CN111801679B - Fingerprint detection device and electronic device - Google Patents

Abstract

A fingerprint detection device and an electronic device are provided, wherein the fingerprint detection device has a plurality of fingerprint detection units distributed in an array or staggered, and each fingerprint detection unit includes: at least one microlens, at least one light-blocking layer below the at least one microlens, and a plurality of optical sensing pixels below the at least one light-blocking layer, wherein the inclined light signals in 2M directions reflected from the finger above the display screen are converged by the at least one microlens and then transmitted to the plurality of optical sensing pixels respectively through openings provided in the at least one light-blocking layer, and the inclined light signals are used to detect the fingerprint information of the finger, and M is a positive integer. By receiving the inclined light signals in 2M directions, not only can the dry finger fingerprint recognition effect be improved, but also the thickness of the optical fingerprint module can be reduced.

Description

Fingerprint detection device and electronic device

This application claims the benefit of priority from the following applications, the entire contents of which are incorporated herein by reference:

On July 12, 2019, a PCT application with application number PCT/CN2019/095780 and invention name “Device and electronic device for fingerprint detection” was submitted to the China Patent Office;

On July 12, 2019, a PCT application with application number PCT/CN2019/095880 and invention name “Fingerprint detection device and electronic device” was submitted to the China Patent Office;

On August 2, 2019, a PCT application with application number PCT/CN2019/099135 and invention title “Fingerprint detection device and electronic device” was submitted to the China Patent Office; and

On September 26, 2019, a PCT application with application number PCT/CN2019/108223 and invention name "Fingerprint detection device and electronic device" was submitted to the China Patent Office.

Technical Field

The embodiments of the present application relate to the field of fingerprint detection, and more specifically, to a fingerprint detection device and an electronic device.

Background technique

As handheld electronic products are increasingly miniaturized in the future, the size of the current lens-type under-screen optical fingerprint products is difficult to adapt to this trend, and it is urgently needed to develop in the direction of thinner thickness, smaller volume, and higher degree of integration. Among the existing miniaturization solutions, the image contrast of collimating hole imaging is related to the depth of the collimating hole, and a relatively large depth is required to achieve high imaging quality. At the same time, this solution has low light utilization. The solution using microlens focusing is limited by the process and lens surface shape. Although the light utilization rate is high, the optical path design is relatively complex and lacks standardized design parameters, which makes it easy for light signals at different positions to overlap, resulting in low signal contrast and low fingerprint imaging quality.

Summary of the invention

Provided are a fingerprint detection device and an electronic device, which can reduce the thickness of an optical fingerprint module while improving the dry finger fingerprint recognition effect.

In a first aspect, a fingerprint detection device is provided, which is suitable for being placed under a display screen to realize under-screen optical fingerprint detection. The fingerprint detection device includes a plurality of fingerprint detection units distributed in an array or staggered, and each of the plurality of fingerprint detection units includes:

Multiple optical sensing pixels;

at least one microlens disposed above the plurality of optical sensing pixels;

At least one light-blocking layer is disposed between the at least one microlens and the plurality of optical sensing pixels, and each of the at least one light-blocking layer is provided with openings corresponding to the plurality of optical sensing pixels;

Among them, the inclined light signals in 2M directions reflected from the finger above the display screen are converged by the at least one microlens, and then transmitted to the multiple optical sensing pixels respectively through the openings set in the at least one light blocking layer, and the inclined light signal is used to detect the fingerprint information of the finger, and M is a positive integer.

The inclined light signals in 2M directions reflected from the finger above the display screen are converged by the one microlens and then transmitted to the multiple optical sensing pixels through the openings set in the at least one light blocking layer. This not only reduces the exposure time of the multiple optical sensing pixels, as well as the thickness and cost of the fingerprint detection device, but also improves the robustness, tolerance, field of view and field of view of the fingerprint detection device, thereby improving the fingerprint recognition effect, especially the fingerprint recognition effect of dry fingers.

In addition, by offsetting the center position of the photosensitive area of each of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel, the image distance of the one microlens can be further increased when the vertical distance between the one microlens and the multiple optical sensing pixels is constant, thereby reducing the thickness of the fingerprint detection device.

Moreover, by symmetrically designing the inclined optical signals in the 2M directions, the structural complexity of the fingerprint detection unit can be simplified. For example, the complexity of the optical path design of at least one light-blocking layer in the fingerprint detection unit can be simplified.

In some possible implementations, the 2M directions include a first direction and a second direction, and a projection of the first direction on the display screen is perpendicular to a projection of the second direction on the display screen.

In some possible implementations, a projection of the first direction or the second direction on the display screen is perpendicular to a polarization direction of the display screen.

By receiving an inclined light signal perpendicular to the polarization direction of the display screen, it is possible to ensure that the light receiving direction of the fingerprint detection unit includes the optimal light receiving direction for fingerprint recognition, thereby increasing the signal amount of the light signal received by the fingerprint detection unit to ensure the fingerprint recognition effect.

In some possible implementations, the plurality of optical sensing pixels form a rectangular array of optical sensing pixels, and a projection of the first direction or the second direction on the rectangular array of optical sensing pixels is parallel to a diagonal direction of the rectangular array of optical sensing pixels.

The first direction is designed to be parallel to the diagonal direction of the rectangular array of optical sensing pixels, so that the light spot area of the optical sensing pixels can move in the direction of the diagonal line, which can not only increase the offset tolerance of the light panel area, but also rationally design the pixel arrangement of the optical sensing pixels for inclined light signals.

In some possible implementations, the at least one microlens is one microlens, the multiple optical sensing pixels are the first column of optical sensing pixels in a 2x2 optical sensing pixel matrix array, the one microlens is located above the center position of the 2x2 optical sensing pixel matrix array, and the second column of optical sensing pixels in the 2x2 optical sensing pixel matrix array is multiplexed as optical sensing pixels in the first column of optical sensing pixels in other fingerprint detection units.

By converging light signals from two directions to two optical sensing pixels through a microlens, the design complexity of the fingerprint detection unit can be effectively simplified.

In some possible implementations, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 2x2 optical sensing pixel matrix array are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 2x2 optical sensing pixel matrix array.

By shifting one optical sensing pixel, the space occupied by the fingerprint detection unit can be saved, thereby reducing the size of the fingerprint detection unit.

In some possible implementations, the at least one microlens is one microlens, the multiple optical sensing pixels are the first row and first column optical sensing pixels and the fourth row and first column optical sensing pixels in the first column of optical sensing pixels in a 4x2 optical sensing pixel matrix array, the one microlens is located above the center position of the side length of the second column of optical sensing pixels in the 4x2 optical sensing pixel matrix array away from the first column of optical sensing pixels, and the optical sensing pixels in the 4x2 optical sensing pixel matrix array except the first row and first column optical sensing pixels and the fourth row and first column optical sensing pixels are multiplexed as optical sensing pixels in other fingerprint detection units.

By converging light signals from two directions to two optical sensing pixels through a microlens, the design complexity of the fingerprint detection unit can be effectively simplified.

In addition, by increasing the length of the path between the microlens and the optical sensing pixel for transmitting the light signal, the thickness of the fingerprint detection unit can be reduced.

In some possible implementations, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 4x2 optical sensing pixel matrix array are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 4x2 optical sensing pixel matrix array.

By shifting one optical sensing pixel, the space occupied by the fingerprint detection unit can be saved to reduce the size of the fingerprint detection unit. In addition, the same fingerprint recognition effect can be achieved with as few microlenses as possible.

In some possible implementations, the multiple optical sensing pixels are a 4x4 optical sensing pixel rectangular array, and the 4x4 optical sensing pixel rectangular array includes 4 2x2 optical sensing pixel rectangular arrays distributed in an array, wherein the 2x2 optical sensing pixel rectangular array in the first column and first row and the 2x2 optical sensing pixel rectangular array in the second row and second column of the 4x4 optical sensing pixel rectangular array are used to receive inclined light signals in one direction, and the 2x2 optical sensing pixel rectangular array in the first column and second row and the 2x2 optical sensing pixel rectangular array in the first row and second column of the 4x4 optical sensing pixel rectangular array are used to receive inclined light signals in another direction.

In some possible implementations, the at least one microlens includes a 3x2 microlens rectangular array and two 2x2 microlens rectangular arrays, the 3x2 microlens rectangular array is located above the first to third columns of optical sensing pixels in the 4x4 optical sensing pixel rectangular array, the two 2x2 microlens rectangular arrays are respectively located above the first and fourth rows of optical sensing pixels in the fourth column of optical sensing pixels in the 4x4 optical sensing pixel rectangular array, and the four microlenses in each of the two 2x2 microlens rectangular arrays are respectively located above the four corners of the corresponding optical sensing pixels, so that the 2x2 optical sensing pixel rectangular array in the first column and first row and the 2x2 optical sensing pixel rectangular array in the second row and second column of the 4x4 optical sensing pixel rectangular array receive an inclined light signal in one diagonal direction of the 4x4 optical sensing pixel rectangular array, and the 2x2 optical sensing pixel rectangular array in the first column and second row and the 2x2 optical sensing pixel rectangular array in the first row and second column of the 4x4 optical sensing pixel rectangular array receive an inclined light signal in another diagonal direction.

In some possible implementations, the microlenses in the two 2x2 microlens rectangular arrays that are located above the side length of the 4x4 optical sensing pixel rectangular array are reused as microlenses in other fingerprint detection units.

In some possible implementations, each optical sensing pixel in the 4x4 optical sensing pixel rectangular array is used to receive light signals converged by microlenses above adjacent optical sensing pixels, so that the 2x2 optical sensing pixel rectangular array in the first column and first row and the 2x2 optical sensing pixel rectangular array in the second row and second column of the 4x4 optical sensing pixel rectangular array receive inclined light signals in the direction of one side length of the 4x4 optical sensing pixel rectangular array, and the 2x2 optical sensing pixel rectangular array in the first column and second row and the 2x2 optical sensing pixel rectangular array in the first row and second column of the 4x4 optical sensing pixel rectangular array receive inclined light signals in the direction of another side length adjacent to the one side length.

In some possible implementations, the microlens in the at least one microlens located above the outer area of the 4×4 optical sensing pixel rectangular array is reused as a microlens in other fingerprint detection units.

In some possible implementations, the multiple optical sensing pixels are multiple rows of optical sensing pixels, at least one row of first optical sensing pixels among the multiple rows of optical sensing pixels is used to receive inclined light signals in one direction, and at least one row of second optical sensing pixels among the multiple rows of optical sensing pixels is used to receive inclined light signals in another direction.

In some possible implementations, each optical sensing pixel in the multiple rows of optical sensing pixels is used to receive the light signal converged by the microlens above the adjacent optical sensing pixel, so that the at least one row of first optical sensing pixels receives the inclined light signal along the arrangement direction of the optical sensing pixels, and the at least one row of second optical sensing pixels receives the inclined light signal along the direction perpendicular to the arrangement direction of the optical sensing pixels.

In some possible implementations, the at least one microlens is a 3x1 microlens rectangular array, the multiple optical sensing pixels are the first column of optical sensing pixels in a 4x2 optical sensing pixel rectangular array, the 3x1 microlens rectangular array is located above the 4x2 optical sensing pixel rectangular array, and the second column of optical sensing pixels in the 4x2 optical sensing pixel rectangular array is multiplexed as optical sensing pixels in other fingerprint detection units.

In some possible implementations, the at least one light-blocking layer is a multi-layer light-blocking layer, and the bottom light-blocking layer in the multi-layer light-blocking layer is provided with a plurality of openings corresponding to the plurality of optical sensing pixels, respectively, so that the at least one microlens can converge the inclined light signals in the 2M directions to the plurality of optical sensing pixels through the plurality of openings.

In some possible implementations, the apertures of the openings in the multi-layer light-blocking layer corresponding to the same optical sensing pixel decrease sequentially from top to bottom.

In some possible implementations, a top light-blocking layer of the multiple light-blocking layers is provided with at least one opening corresponding to the plurality of optical sensing pixels.

In some possible implementations, the at least one light-blocking layer is a light-blocking layer, and the light-blocking layer is provided with a plurality of inclined holes corresponding to the plurality of optical sensing pixels, respectively, so that the at least one microlens converges the inclined light signals in the 2M directions to the plurality of optical sensing pixels through the plurality of openings, respectively.

In some possible implementations, the thickness of the light-blocking layer is greater than or equal to a preset thickness, so that the multiple inclined holes are respectively used to transmit the inclined optical signals in the 2M directions.

In some possible implementations, the fingerprint detection device further includes a transparent medium layer, and the transparent medium layer is used to connect the at least one microlens, the at least one light blocking layer, and the plurality of optical sensing pixels.

In some possible implementations, the fingerprint detection device further includes a filter layer, which is disposed in the light path between the at least one microlens and the plurality of optical sensing pixels or above the microlens, and is configured to filter out light signals in non-target bands to transmit light signals in target bands.

In a second aspect, an electronic device is provided, including:

Display screen; and

The fingerprint detection device described in the first aspect or any possible implementation of the first aspect, wherein the device is arranged below the display screen to realize under-screen optical fingerprint detection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic structural diagram of an electronic device to which the present application may be applied.

FIG. 2 is a schematic cross-sectional view of the electronic device shown in FIG. 1 .

FIG. 3 is another schematic structural diagram of an electronic device to which the present application may be applied.

FIG. 4 is a schematic cross-sectional view of the electronic device shown in FIG. 3 .

5 to 29 are schematic structural diagrams of the fingerprint detection unit of the embodiments of the present application.

FIG. 30 is a schematic top view of the fingerprint detection device according to an embodiment of the present application.

FIG. 31 is a schematic side sectional view of the fingerprint detection device shown in FIG. 30 along the BB′ direction.

FIG32 is a schematic structural diagram of light path transmission in a scenario where the light receiving direction of the finger is perpendicular to the fingerprint direction according to an embodiment of the present application.

FIG33 is a schematic structural diagram of light path transmission in a scenario where the light receiving direction of the finger is parallel to the fingerprint direction according to an embodiment of the present application.

34 to 37 are schematic structural diagrams of the relationship between the polarization direction of the display screen and the light receiving direction of the fingerprint detection device according to the embodiment of the present application.

38 to 43 are schematic structural diagrams of a fingerprint detection unit or a fingerprint detection device according to an embodiment of the present application.

44 and 45 are respectively a side cross-sectional view of a fingerprint detection device for receiving a single direction and a schematic diagram of an offset tolerance of a light spot area in an optical sensing pixel according to an embodiment of the present application.

46 and 47 are respectively a side cross-sectional view of a fingerprint detection device for receiving two directions according to an embodiment of the present application and a schematic diagram of the offset tolerance of a light spot area in an optical sensing pixel.

48 to 67 are another schematic structural diagram of a fingerprint detection unit or a fingerprint detection device according to an embodiment of the present application.

Figure 68 is a schematic structural diagram of structural parameters in the fingerprint detection device of an embodiment of the present application.

Figures 69 and 70 are both schematic top views of the fingerprint detection device shown in Figure 68.

Detailed ways

The technical solution in this application will be described below in conjunction with the accompanying drawings.

The technical solution of the embodiment of the present application can be applied to various electronic devices. For example, portable or mobile computing devices such as smart phones, laptops, tablet computers, gaming devices, and other electronic devices such as electronic databases, cars, bank automated teller machines (ATMs), etc. However, the embodiment of the present application is not limited to this.

The technical solution of the embodiment of the present application can be used for biometric identification technology. Among them, biometric identification technology includes but is not limited to fingerprint recognition, palm print recognition, iris recognition, face recognition, and liveness recognition. For the sake of convenience, the following description takes fingerprint recognition technology as an example.

The technical solution of the embodiment of the present application can be used for under-screen fingerprint recognition technology and in-screen fingerprint recognition technology.

Under-screen fingerprint recognition technology refers to installing a fingerprint recognition module under the display screen, so as to realize fingerprint recognition operation within the display area of the display screen, and there is no need to set a fingerprint collection area on the front of the electronic device except for the display area. Specifically, the fingerprint recognition module uses the light returned from the top surface of the display component of the electronic device to perform fingerprint sensing and other sensing operations. This returned light carries information about objects (such as fingers) that are in contact or close to the top surface of the display component, and the fingerprint recognition module located below the display component collects and detects this returned light to realize under-screen fingerprint recognition. Among them, the design of the fingerprint recognition module can be to achieve the desired optical imaging by properly configuring the optical elements for collecting and detecting the returned light, thereby detecting the fingerprint information of the finger.

Correspondingly, in-display fingerprint recognition technology refers to installing the fingerprint recognition module or part of the fingerprint recognition module inside the display screen, so as to realize fingerprint recognition operation within the display area of the display screen, without setting up a fingerprint collection area in the area other than the display area on the front of the electronic device.

FIG1 to FIG4 are schematic diagrams of electronic devices to which the embodiments of the present application can be applied. FIG1 and FIG3 are directional schematic diagrams of the electronic device 10, and FIG2 and FIG4 are cross-sectional schematic diagrams of the electronic device 10 shown in FIG1 and FIG3, respectively. Referring to FIG1 to FIG4, the electronic device 10 may include a display screen 120 and an optical fingerprint recognition module 130.

Among them, the display screen 120 can be a self-luminous display screen, which uses a display unit with self-luminescence as a display pixel. For example, the display screen 120 can be an organic light-emitting diode (OLED) display screen or a micro-light-emitting diode (Micro-LED) display screen. In other alternative embodiments, the display screen 120 can also be a liquid crystal display (LCD) or other passive light-emitting display screens, which is not limited by the embodiments of the present application. Further, the display screen 120 can also be specifically a touch display screen, which can not only display the picture, but also detect the user's touch or press operation, thereby providing a human-computer interaction interface for the user. For example, in one embodiment, the electronic device 10 may include a touch sensor, and the touch sensor may be specifically a touch panel (TP), which may be arranged on the surface of the display screen 120, or may be partially integrated or wholly integrated into the display screen 120, thereby forming the touch display screen.

The optical fingerprint module 130 includes an optical fingerprint sensor, which includes a sensing array 133 having a plurality of optical sensing units 131 (also referred to as optical sensing pixels, photosensitive pixels, pixel units, etc.). The area where the sensing array 133 is located or its sensing area is the fingerprint detection area 103 (also referred to as a fingerprint collection area, a fingerprint recognition area, etc.) of the optical fingerprint module 130. For example, the optical sensing unit 131 may be a photo detector, that is, the sensing array 133 may specifically be a photo detector array, which includes a plurality of photo detectors distributed in an array.

The optical fingerprint module 130 is disposed in a local area below the display screen 120 .

Please continue to refer to FIG. 1 , the fingerprint detection area 103 may be located in the display area of the display screen 120. In an alternative embodiment, the optical fingerprint module 130 may also be set at other locations, such as the side of the display screen 120 or the non-light-transmissive area at the edge of the electronic device 10, and the optical signal from at least part of the display area of the display screen 120 is guided to the optical fingerprint module 130 through the optical path design, so that the fingerprint detection area 103 is actually located in the display area of the display screen 120.

For the electronic device 10, when the user needs to unlock the electronic device 10 or perform other fingerprint verification, the user only needs to press the finger on the fingerprint detection area 103 located on the display screen 120 to input the fingerprint. Since the fingerprint detection can be realized in the screen, the electronic device 10 adopting the above structure does not need to reserve a special space on the front to set the fingerprint button (such as the Home button), so that a full-screen solution can be adopted, that is, the display area of the display screen 120 can be basically extended to the front of the entire electronic device 10.

Please continue to refer to Figure 2. The optical fingerprint module 130 may include a light detection part 134 and an optical component 132. The light detection part 134 includes the sensing array 133 (also referred to as an optical fingerprint sensor) and a reading circuit and other auxiliary circuits electrically connected to the sensing array 133, which may be made on a chip (Die) through a semiconductor process, such as an optical imaging chip or an optical fingerprint sensor. The optical component 132 may be arranged above the sensing array 133 of the light detection part 134, which may specifically include a filter layer (Filter), a light guide layer or a light path guiding structure, and other optical elements. The filter layer may be used to filter out the ambient light that penetrates the finger, and the light guide layer or the light path guiding structure is mainly used to guide the reflected light reflected from the finger surface to the sensing array 133 for optical detection.

In some embodiments of the present application, the optical component 132 can be packaged in the same optical fingerprint component as the light detection part 134. For example, the optical component 132 can be packaged in the same optical fingerprint chip as the optical detection part 134, or the optical component 132 can be arranged outside the chip where the light detection part 134 is located, such as attaching the optical component 132 above the chip, or integrating some components of the optical component 132 into the above chip.

In some embodiments of the present application, the area where the sensing array 133 of the optical fingerprint module 130 is located or the light sensing range corresponds to the fingerprint detection area 103 of the optical fingerprint module 130. The fingerprint collection area 103 of the optical fingerprint module 130 may be equal to or not equal to the area or light sensing range of the area where the sensing array 133 of the optical fingerprint module 130 is located, and the embodiments of the present application do not specifically limit this.

For example, by guiding the light path in a light collimation manner, the fingerprint detection area 103 of the optical fingerprint module 130 can be designed to be substantially consistent with the area of the sensing array of the optical fingerprint module 130 .

For another example, the area of the fingerprint detection area 103 of the optical fingerprint module 130 can be made larger than the area of the sensing array 133 of the optical fingerprint module 130 through an optical path design such as lens imaging, a reflective folded optical path design, or other light converging or reflecting optical path designs.

The light path guiding structure that the optical component 132 may include is exemplarily described below.

Taking the optical collimator with a through-hole array with a high aspect ratio adopted in the light path guiding structure as an example, the optical collimator can be specifically a collimator (Collimator) layer made on a semiconductor silicon wafer, which has multiple collimation units or microholes. The collimation unit can be specifically a small hole. Among the reflected light reflected from the finger, the light perpendicularly incident to the collimation unit can pass through and be received by the sensor chip below it, while the light with too large incident angle is attenuated after multiple reflections inside the collimation unit. Therefore, each sensor chip can basically only receive the reflected light reflected from the fingerprint pattern directly above it, which can effectively improve the image resolution and thus improve the fingerprint recognition effect.

Taking the optical path design of the optical lens adopted by the optical path guiding structure as an example, the optical path guiding structure can be an optical lens (Lens) layer, which has one or more lens units, such as a lens group composed of one or more aspherical lenses, which is used to converge the reflected light reflected from the finger to the sensing array 133 of the light detection part 134 below it, so that the sensing array 133 can be imaged based on the reflected light, thereby obtaining the fingerprint image of the finger. Further, the optical lens layer can also form a pinhole or micro-aperture diaphragm in the optical path of the lens unit, for example, one or more light shielding sheets can be formed in the optical path of the lens unit, wherein at least one light shielding sheet can form a light-transmitting micro-aperture in the optical axis or optical center area of the lens unit, and the light-transmitting micro-aperture can be used as the above-mentioned pinhole or micro-aperture diaphragm. The pinhole or micro-aperture diaphragm can cooperate with the optical lens layer and/or other optical film layers above the optical lens layer to expand the field of view of the optical fingerprint module 130 to improve the fingerprint imaging effect of the optical fingerprint module 130.

Taking the optical path design of the light path guiding structure using a micro-lens layer as an example, the light path guiding structure may be a micro-lens array formed by a plurality of micro-lenses, which may be formed above the sensing array 133 of the light detection part 134 by a semiconductor growth process or other processes, and each micro-lens may correspond to one of the sensing units of the sensing array 133. In addition, other optical film layers, such as a dielectric layer or a passivation layer, may be formed between the micro-lens layer and the sensing unit. More specifically, a light-blocking layer (or light-shielding layer, light-blocking layer, etc.) having micro-holes (or openings) may be included between the micro-lens layer and the sensing unit, wherein the micro-holes are formed between the corresponding micro-lenses and the sensing unit, and the light-blocking layer may block the optical interference between the adjacent micro-lenses and the sensing unit, and allow the light corresponding to the sensing unit to converge into the micro-holes through the micro-lenses and be transmitted to the sensing unit via the micro-holes for optical fingerprint imaging.

It should be understood that the above-mentioned several implementation schemes for the light path guiding structure can be used alone or in combination.

For example, a microlens layer may be further provided above or below the collimator layer or the optical lens layer. Of course, when the collimator layer or the optical lens layer is used in combination with the microlens layer, the specific stacking structure or optical path may need to be adjusted according to actual needs.

On the other hand, the optical component 132 may also include other optical elements, such as a filter layer or other optical film, which may be arranged between the light path guiding structure and the optical fingerprint sensor or between the display screen 120 and the light path guiding structure, and is mainly used to isolate the influence of external interference light on optical fingerprint detection. Among them, the filter layer can be used to filter out the ambient light that penetrates the finger and enters the optical fingerprint sensor through the display screen 120. Similar to the light path guiding structure, the filter layer can be set for each optical fingerprint sensor to filter out interference light, or a large-area filter layer can be used to cover the multiple optical fingerprint sensors at the same time.

The fingerprint recognition module 140 can be used to collect fingerprint information (such as fingerprint image information) of the user.

Take the display screen 120 as an example, which uses a display screen with a self-luminous display unit, such as an organic light-emitting diode (OLED) display screen or a micro-light-emitting diode (Micro-LED) display screen. The optical fingerprint module 130 can use the display unit (i.e., OLED light source) of the OLED display screen 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 presses on the fingerprint detection area 103, the display screen 120 emits a beam of light 111 to the target finger 140 above the fingerprint detection area 103. The light 111 is reflected on the surface of the finger 140 to form reflected light or is scattered inside the finger 140 to form scattered light (transmitted light). In the relevant patent applications, for the convenience of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Since the ridge 141 and valley 142 of the fingerprint have different reflective capabilities for light, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint valley have different light intensities. After passing through the optical component 132, the reflected light is received by the sensing array 133 in the optical fingerprint module 130 and converted into a corresponding electrical signal, i.e., a fingerprint detection signal. Based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby realizing the optical fingerprint recognition function in the electronic device 10.

In other alternatives, the optical fingerprint module 130 may also use a built-in light source or an external light source to provide an optical signal for fingerprint detection and identification. In this case, the optical fingerprint module 130 can be applied not only to self-luminous display screens such as OLED display screens, but also to non-self-luminous display screens, such as liquid crystal display screens or other passive light-emitting display screens.

Taking the application in a liquid crystal display screen having a backlight module and a liquid crystal panel as an example, in order to support the under-screen fingerprint detection of the liquid crystal display screen, the optical fingerprint system of the electronic device 10 may also include an excitation light source for optical fingerprint detection, and the excitation light source may be specifically an infrared light source or a light source of non-visible light of a specific wavelength, which may be arranged below the backlight module of the liquid crystal display screen or in the edge area below the protective cover of the electronic device 10, and the optical fingerprint module 130 may be arranged below the edge area of the liquid crystal panel or the protective cover and guided through the optical path so that the fingerprint detection light can reach the optical fingerprint module 130; or, the optical fingerprint module 130 may also be arranged below the backlight module, and the backlight module may allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130 by opening holes or other optical designs in the film layers such as the diffuser, the brightness enhancement sheet, and the reflector. When the optical fingerprint module 130 adopts a built-in light source or an external light source to provide an optical signal for fingerprint detection, its detection principle is consistent with the above description.

In a specific implementation, the electronic device 10 may further include a transparent protective cover plate, which may be a glass cover plate or a sapphire cover plate, which is located above the display screen 120 and covers the front of the electronic device 10. Therefore, in the embodiment of the present application, the so-called finger pressing on the display screen 120 actually refers to pressing the cover plate above the display screen 120 or the surface of the protective layer covering the cover plate.

On the other hand, the optical fingerprint module 130 may include only one optical fingerprint sensor. In this case, the fingerprint detection area 103 of the optical fingerprint module 130 is small in area and fixed in position. Therefore, when the user inputs the fingerprint, the user needs to press the finger to a specific position of the fingerprint detection area 103. Otherwise, the optical fingerprint module 130 may not be able to collect the fingerprint image and cause a poor user experience. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. The plurality of optical fingerprint sensors may be arranged side by side under the display screen 120 by splicing, and the sensing areas of the plurality of optical fingerprint sensors together constitute the fingerprint detection area 103 of the optical fingerprint module 130. Thus, the fingerprint detection area 103 of the optical fingerprint module 130 can be extended to the main area of the lower half of the display screen, that is, to the area where the finger is usually pressed, thereby realizing a blind fingerprint input operation. Furthermore, when the number of the optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half of the display area or even the entire display area, thereby realizing half-screen or full-screen fingerprint detection.

Please refer to Figures 3 and 4. The optical fingerprint module 130 in the electronic device 10 may include a plurality of optical fingerprint sensors. The plurality of optical fingerprint sensors may be arranged side by side below the display screen 120 by, for example, splicing, and the sensing areas of the plurality of optical fingerprint sensors together constitute the fingerprint detection area 103 of the optical fingerprint device 130.

Furthermore, the optical assembly 132 may include a plurality of light path guiding structures, each of which corresponds to an optical fingerprint sensor (i.e., the sensing array 133) and is respectively disposed above the corresponding optical fingerprint sensor. Alternatively, the plurality of optical fingerprint sensors may also share an integral light path guiding structure, i.e., the light path guiding structure has an area large enough to cover the sensing arrays of the plurality of optical fingerprint sensors.

Taking the optical collimator with a through-hole array having a high aspect ratio as an example, when the optical fingerprint module 130 includes multiple optical fingerprint sensors, one or more collimation units can be configured for one optical sensing unit in the optical sensing array of each optical fingerprint sensor, and are arranged on top of the corresponding optical sensing unit. Of course, the multiple optical sensing units can also share one collimation unit, that is, the one collimation unit has a large enough aperture to cover multiple optical sensing units. Since one collimation unit can correspond to multiple optical sensing units or one optical sensing unit corresponds to multiple collimation units, the correspondence between the spatial period of the display screen 120 and the spatial period of the optical fingerprint sensor is destroyed. Therefore, even if the spatial structure of the light-emitting display array of the display screen 120 is similar to the spatial structure of the optical sensing array of the optical fingerprint sensor, it can effectively avoid the optical fingerprint module 130 from using the light signal passing through the display screen 120 to perform fingerprint imaging to generate moiré fringes, thereby effectively improving the fingerprint recognition effect of the optical fingerprint module 130.

Taking the optical component 132 using an optical lens as an example, when the optical fingerprint module 130 includes multiple sensor chips, an optical lens can be configured for each sensor chip to perform fingerprint imaging, or an optical lens can be configured for multiple sensor chips to achieve light convergence and fingerprint imaging. Even when a sensor chip has two sensing arrays (Dual Array) or multiple sensing arrays (Multi-Array), two or more optical lenses can be configured for the sensor chip to cooperate with the two sensing arrays or multiple sensing arrays for optical imaging, thereby reducing the imaging distance and enhancing the imaging effect.

It should be understood that Figures 1 to 4 are merely examples of the present application and should not be construed as limiting the present application.

For example, the present application does not specifically limit the number, size, and arrangement of fingerprint sensors, which can be adjusted according to actual needs. For example, the optical fingerprint module 130 may include multiple fingerprint sensors distributed in a square or circular shape.

It should be noted that, assuming that the optical guiding structure included in the optical component 132 is an optical collimator or a microlens array, the effective field of view of the sensing array 133 of the optical fingerprint module 130 is limited by the area of the optical component. Taking the microlens array as an example, in a general design, the microlens array is located directly above or obliquely above the sensing array 133, and one microlens corresponds to one optical sensing unit, that is, each microlens in the microlens array focuses the received light to the optical sensing unit corresponding to the same microlens. Therefore, the fingerprint recognition area of the sensing array 133 is affected by the size of the microlens array.

Therefore, how to improve the fingerprint recognition area has become a technical problem that needs to be solved urgently.

The fingerprint detection device of the embodiment of the present application is applicable to the underside of the display screen to realize the under-screen optical fingerprint detection. The fingerprint detection device can be applicable to the electronic device 10 shown in Figures 1 to 4, or the device can be the optical fingerprint module 130 shown in Figures 2 or 4. For example, the fingerprint detection device includes a plurality of fingerprint detection units 21 as shown in Figure 5.

It should be understood that the fingerprint detection device may include a plurality of fingerprint detection units distributed in an array or staggered, and may also include a plurality of fingerprint detection units distributed in a centrally symmetrical or axially symmetrical manner, and the embodiments of the present application do not specifically limit this. For example, the fingerprint detection device may include a plurality of fingerprint detection units that are independently arranged in structure but staggered in arrangement. For example, two adjacent columns or rows of fingerprint detection units in the fingerprint detection device are staggered. Of course, the fingerprint detection device may also include a plurality of fingerprint detection units that are staggered in structure. For example, the microlens in each fingerprint detection unit in the fingerprint detection device can converge the received inclined light signal to the optical sensing pixels under the microlenses in the adjacent plurality of fingerprint detection units. In other words, each microlens converges the received inclined light signal to the optical sensing pixels under the plurality of microlenses adjacent to the same microlens.

Each of the multiple fingerprint detection units includes multiple optical sensing pixels, at least one microlens and at least one light blocking layer.

In a specific implementation, the at least one microlens can be arranged above the multiple optical sensing pixels, or the multiple optical sensing pixels can be arranged respectively below multiple microlenses adjacent to the one microlens; the at least one light-blocking layer can be arranged between the at least one microlens and the multiple optical sensing pixels, and each of the at least one light-blocking layer is provided with openings corresponding to the multiple optical sensing pixels. The inclined light signals in multiple directions reflected from the finger above the display screen are converged by the at least one microlens and transmitted to the multiple optical sensing pixels respectively through the openings provided in the at least one light-blocking layer, and the inclined light signals are used to detect the fingerprint information of the finger.

The inclined light signals in multiple directions received by at least one microlens may be the incident directions of the inclined light for the at least one microlens. For example, the at least one microlens may be regarded as a whole. In this case, in a top view, the multiple directions may be the light signals received by the at least one microlens from four directions, namely, up, down, left, and right. The angles of the inclined light signals in these four directions relative to the plane where the display screen is located may be the same or different. The multiple directions may be directions for the plane where the display screen is located, or directions for three-dimensional space. The multiple directions may be different from each other, or may be partially different.

The microlens may be any lens with a converging function, which is used to increase the field of view and the amount of light signal transmitted to the photosensitive pixel. The material of the microlens may be an organic material, such as a resin.

The optical sensing pixel may be a photoelectric sensor for converting an optical signal into an electrical signal. Optionally, the optical sensing pixel may adopt a complementary metal oxide semiconductor (CMOS) device, a semiconductor device composed of a PN junction, having a unidirectional conductive property. Optionally, the optical sensing pixel has a light sensitivity greater than a first predetermined threshold for blue light, green light, red light or infrared light, and a quantum efficiency greater than a second predetermined threshold. For example, the first predetermined threshold may be 0.5v/lux-sec, and the second predetermined threshold may be 40%. In other words, the photosensitive pixel has a higher light sensitivity and a higher quantum efficiency for blue light (wavelength of 460±30nm), green light (wavelength of 540±30nm), red light or infrared light (wavelength ≥610nm), so as to facilitate the detection of the corresponding light.

It should be noted that the embodiments of the present application do not limit the specific shapes of the microlens and the optical sensing pixel. For example, each of the multiple optical sensing pixels can be a polygonal pixel such as a quadrilateral or hexagonal pixel, or a pixel of other shapes, such as a circular pixel, so that the multiple optical sensing pixels have higher symmetry, higher sampling efficiency, equidistant adjacent pixels, better angular resolution, and less aliasing effect. In addition, the above parameters for the optical sensing pixels can correspond to the light required for fingerprint detection. For example, if the light required for fingerprint detection is only light of one band, the above parameters of the photosensitive pixels only need to meet the requirements of light of that band.

The signals received by the multiple optical sensing pixels are inclined light signals in multiple directions, that is, light signals in multiple directions with oblique incidence.

When the dry hand fingerprint is not in good contact with the OLED screen, the contrast between the fingerprint ridges and the fingerprint valleys in the vertical direction of the fingerprint image is poor, and the image is so blurred that the fingerprint lines cannot be distinguished. This application uses a reasonable optical path design to allow the optical path to receive inclined light signals. While being able to better acquire normal finger fingerprints, it can better detect dry finger fingerprint images. In normal life scenarios, such as after washing hands, getting up in the morning, dusting fingers, and low temperatures, fingers are usually drier and their stratum corneum is uneven. When they are pressed on the OLED screen, poor contact will occur in local areas of the fingers. The emergence of this situation causes the current optical fingerprint solution to be ineffective in dry hand fingerprint recognition. The beneficial effect of this application is to improve the imaging effect of dry hand fingerprints and make the dry hand fingerprint image clearer.

In addition, the one microlens can perform non-direct light imaging (i.e., oblique light imaging) on the oblique light signals in the multiple directions, which can shorten the thickness of the optical path design layer between the one microlens and the optical sensing pixel array, thereby effectively reducing the thickness of the fingerprint detection device.

At the same time, by imaging the inclined light signals in multiple directions, the object-side numerical aperture of the optical system can be expanded, thereby improving the robustness and tolerance of the fingerprint detection device. The numerical aperture can be used to measure the angle range of light that can be collected by the at least one microlens. In other words, the multiple optical sensing pixels can also expand the field of view and field of view of the fingerprint detection unit by receiving light signals in multiple directions, thereby increasing the field of view and field of view of the fingerprint detection device. For example, the field of view of the fingerprint detection device can be expanded from ^6x9mm2 to 7.5x10.5 ^mm2 , further improving the fingerprint recognition effect.

Moreover, by arranging a plurality of optical sensing pixels under the at least one microlens, when the number of the at least one microlens is not equal to the number of the plurality of optical sensing pixels, the spatial period of the microlens (i.e., the spacing between adjacent microlenses) and the spatial period of the optical sensing pixels (i.e., the spacing between adjacent optical sensing pixels) can be made unequal, thereby avoiding the appearance of moiré fringes in the fingerprint image and improving the fingerprint recognition effect. In particular, when the number of the at least one microlens is less than the number of the plurality of optical sensing pixels, the cost of the lens can be reduced and the density of the plurality of optical sensing pixels can be increased, thereby reducing the size and cost of the fingerprint detection device.

At the same time, a single fingerprint detection unit can multiplex light signals in multiple directions (for example, a single microlens can multiplex light signals at four angles), and light beams with different object aperture angles can be split for imaging, effectively increasing the amount of light entering the fingerprint detection device, thereby reducing the exposure time of the optical sensing pixel.

Moreover, since the multiple optical sensing pixels can respectively receive inclined light signals from multiple directions, the multiple optical sensing pixels can be divided into multiple optical sensing pixel groups according to the directions of the inclined light signals. The multiple optical sensing pixel groups can be used to receive the inclined light signals from the multiple directions, that is, each optical sensing pixel group can generate a fingerprint image based on the received inclined light signals, and thus the multiple optical sensing pixel groups can be used to generate multiple fingerprint images. In this case, the multiple fingerprint images can be superimposed to obtain a high-resolution fingerprint image, and then fingerprint recognition can be performed based on this high-resolution fingerprint image, which can improve the fingerprint recognition performance.

Based on the above analysis, it can be known that the inclined light signals in multiple directions reflected from the finger above the display screen are converged by the at least one microlens and then transmitted to the multiple optical sensing pixels respectively through the openings set in the at least one light blocking layer. This can not only reduce the exposure time of the multiple optical sensing pixels, as well as the thickness and cost of the fingerprint detection device, but also improve the robustness, tolerance, field of view and field of view of the fingerprint detection device, thereby improving the fingerprint recognition effect, especially the fingerprint recognition effect of dry fingers.

The fingerprint detection unit of the embodiment of the present application is described below with reference to the accompanying drawings.

In some embodiments of the present application, the number of the at least one microlens is equal to the number of the plurality of optical sensing pixels, wherein a microlens is disposed above each of the plurality of optical sensing pixels.

In one implementation, the at least one microlens is a 2x2 microlens rectangular array, the multiple optical sensing pixels are a 2x2 optical sensing pixel rectangular array, and a microlens is arranged directly above each optical sensing pixel in the 2x2 optical sensing pixel rectangular array. In another implementation, the at least one microlens is a 2x2 microlens rectangular array, the multiple optical sensing pixels are a 2x2 optical sensing pixel rectangular array, and a microlens is arranged obliquely above each optical sensing pixel in the 2x2 optical sensing pixel rectangular array. For example, as shown in FIG5, the fingerprint detection unit 21 may include 4 optical sensing pixels 211 and 4 microlenses 212 distributed in a rectangular array, wherein a microlens 212 is arranged directly above each optical sensing pixel 211. At this time, in terms of optical path design, as shown in FIG6, the fingerprint detection unit 21 may include a top light blocking layer and a bottom light blocking layer. Among them, the top light blocking layer may include 4 openings 2141 corresponding to the 4 microlenses 212 respectively, and the bottom light blocking layer may include 4 openings 213 corresponding to the 4 microlenses 212 respectively.

During the light transmission process, the 2x2 microlens rectangular array receives the inclined light signals in the multiple directions in a clockwise direction, and each microlens in the 2x2 microlens rectangular array converges the received inclined light signals to the optical sensing pixels under the adjacent microlens in the clockwise direction, or the 2x2 microlens rectangular array receives the inclined light signals in the multiple directions in a counterclockwise direction, and each microlens in the 2x2 microlens rectangular array converges the received inclined light signals to the optical sensing pixels under the adjacent microlens in the counterclockwise direction. 7, the four microlenses 212 can converge the oblique light signals in multiple directions to the four optical sensing pixels 211 along the following paths: the microlens 212 in the upper right corner converges the received oblique light signal to the optical sensing pixel 211 in the upper left corner, the microlens 212 in the upper left corner converges the received oblique light signal to the optical sensing pixel 211 in the lower left corner, the microlens 212 in the lower left corner converges the received oblique light signal to the optical sensing pixel 211 in the lower right corner, and the microlens 212 in the lower right corner converges the received oblique light signal to the optical sensing pixel 211 in the upper right corner. Therefore, when the fingerprint detection device includes a plurality of fingerprint detection units distributed in an array, a plurality of fingerprint images can be generated based on the received light signals in multiple directions, and then a high-resolution fingerprint image can be obtained to improve the fingerprint recognition effect.

In other words, the 4x4 fingerprint detection unit rectangular array may include an optical sensing pixel array as shown in FIG8, wherein "1" represents an optical sensing pixel for receiving an oblique light signal in a first direction, "2" represents an optical sensing pixel for receiving an oblique light signal in a second direction, "3" represents an optical sensing pixel for receiving an oblique light signal in a third direction, and "4" represents an optical sensing pixel for receiving an oblique light signal in a fourth direction. In other words, the optical sensing pixels represented by "1", "2", "3" and "4" can be used to generate a fingerprint image respectively, that is, a total of 4 fingerprint images can be generated, and these 4 fingerprint images can be used to merge into a high-resolution fingerprint image, thereby improving the recognition effect of the fingerprint detection device. In conjunction with FIG7, the first direction to the fourth direction can be the directions where the oblique light signals received by the lower right microlens 212, the upper right microlens 212, the upper left microlens 212 and the lower left microlens 212 are located.

FIG. 9 is a side view of a fingerprint detection device located below a display screen.

As shown in FIG9 , the fingerprint detection device may include microlenses 212 distributed in an array, a top light-blocking layer and a bottom light-blocking layer located below the microlenses 212, and optical sensing pixels distributed in an array located below the bottom light-blocking layer, wherein for each microlens 212, the top light-blocking layer and the bottom light-blocking layer are respectively formed with corresponding openings 2141 and openings 213. The fingerprint detection device is arranged below the display screen 216. Each microlens 212 converges the received inclined light signal with a specific direction (the light signal shown by the solid line in the figure) to the corresponding optical sensing pixel through the corresponding opening 2141 and opening 213, and transmits the received inclined light signal with a non-specific direction (the light signal shown by the dotted line in the figure) to the area of the light-blocking layer other than the opening 2141 and the opening 214, so as to avoid being received by other optical sensing pixels, thereby causing segmentation imaging of the fingerprint image.

FIG. 10 is a schematic diagram of the optical path of optical signals tilted in two directions according to an embodiment of the present application.

In combination with Figure 7, Figure 10 may be a schematic side sectional view of the fingerprint detection device including the fingerprint detection unit shown in Figure 7 in the AA' direction. At this time, one microlens 212 in the fingerprint detection unit (for example, the lower left microlens 212 shown in Figure 7) converges the received inclined light signal in one direction (i.e., the fourth direction) (the light signal shown by the solid line in Figure 10) to the corresponding optical sensing pixel (for example, the lower right optical sensing pixel 211 shown in Figure 7) through the corresponding opening 2141 and the opening 213, and another microlens 212 in the fingerprint detection unit (for example, the upper right microlens 212 shown in Figure 7) converges the received inclined light signal in another direction (i.e., the second direction) (the light signal shown by the dotted line in Figure 10) to the corresponding optical sensing pixel (for example, the upper left optical sensing pixel 211 shown in Figure 7) through the corresponding opening 2141 and the opening 213.

During the fingerprint collection process, the fingerprint recognition area (also called fingerprint collection area or fingerprint detection area) of the fingerprint detection device shown in FIG10 includes a first recognition area and a second recognition area, wherein the fingerprint recognition area corresponding to the microlens 212 for converging the oblique light signal in the second direction is the first recognition area, and the fingerprint recognition area corresponding to the microlens for converging the oblique light signal in the fourth direction is the second recognition area. The first recognition area is offset to the right by a first increased area relative to the array formed by the optical sensing pixels, and the second recognition area is offset to the left by a second increased area relative to the array formed by the optical sensing pixels. In other words, assuming that the first recognition area and the second recognition area are both equal to the area where the optical sensing array is located, relative to the fingerprint detection device that only receives light signals in one direction, the recognition area of the fingerprint detection device shown in FIG10 additionally includes the first increased area and the second increased area, which effectively increases the visible area (i.e., the field of view). In addition, the overlapping area of the first recognition area and the second recognition area can effectively improve the image resolution of the fingerprint image, thereby improving the fingerprint recognition effect.

It should be understood that the optical path design shown in FIG. 7 is merely an example of the present application and should not be construed as a limitation to the present application.

As for the optical path design, in another implementation, the 2x2 microlens rectangular array receives the inclined light signals in the multiple directions along the diagonal direction of the 2x2 microlens rectangular array, and each microlens in the 2x2 microlens rectangular array converges the received inclined light signals to the optical sensing pixel below the adjacent microlens in the diagonal direction. For example, as shown in FIG11 and FIG12, the four microlenses 212 can converge the inclined light signals in multiple directions to the four optical sensing pixels 211 respectively along the following paths: the microlens 212 in the upper right corner converges the received inclined light signal to the optical sensing pixel 211 in the lower left corner, the microlens 212 in the lower left corner converges the received inclined light signal to the optical sensing pixel 211 in the upper right corner, the microlens 212 in the upper left corner converges the received inclined light signal to the optical sensing pixel 211 in the lower right corner, and the microlens 212 in the lower right corner converges the received inclined light signal to the optical sensing pixel 211 in the upper left corner. Therefore, when the fingerprint detection device includes a plurality of fingerprint detection units distributed in an array, a plurality of fingerprint images can be generated based on light signals received in multiple directions, thereby obtaining a high-resolution fingerprint image to improve the fingerprint recognition effect.

Similarly, the 4x4 rectangular array of fingerprint detection units may include an optical sensing pixel array as shown in FIG8, wherein "1" represents an optical sensing pixel for receiving an oblique light signal in a first direction, "2" represents an optical sensing pixel for receiving an oblique light signal in a second direction, "3" represents an optical sensing pixel for receiving an oblique light signal in a third direction, and "4" represents an optical sensing pixel for receiving an oblique light signal in a fourth direction. In other words, the optical sensing pixels represented by "1", "2", "3" and "4" can be used to generate a fingerprint image respectively, that is, a total of 4 fingerprint images can be generated, and these 4 fingerprint images can be used to merge into a high-resolution fingerprint image, thereby improving the recognition effect of the fingerprint detection device. In conjunction with FIG11, the first to fourth directions can be the directions where the oblique light signals received by the lower left microlens 212, the lower right microlens 212, the upper right microlens 212, and the upper left microlens 212 are located.

The fingerprint detection device may include at least one light-blocking layer and an optical sensing pixel array. In one implementation, the at least one light-blocking layer is a plurality of light-blocking layers. One opening in the pinhole array in each of the plurality of light-blocking layers corresponds to a plurality of optical sensing pixels in the optical sensing pixels, or one opening in the pinhole array in each of the plurality of light-blocking layers corresponds to one optical sensing pixel in the optical sensing pixels. For example, one opening in the pinhole array in the top light-blocking layer in the plurality of light-blocking layers corresponds to a plurality of optical sensing pixels in the optical sensing pixels. For another example, one opening in the pinhole array in the top light-blocking layer in the plurality of light-blocking layers corresponds to one optical sensing pixel in the optical sensing pixels. One opening in the pinhole array in the bottom light-blocking layer in the plurality of light-blocking layers corresponds to one optical sensing pixel in the optical sensing pixels. Optionally, the apertures of the openings corresponding to the same optical sensing pixel in the plurality of light-blocking layers decrease in sequence from top to bottom. In another implementation, the at least one light-blocking layer is a light-blocking layer. Optionally, the thickness of the one light-blocking layer is greater than a preset threshold. Optionally, the metal wiring layer of the optical sensing pixel array is arranged at the rear focal plane position of the microlens array, and the metal wiring layer has an opening above each optical sensing pixel in the optical sensing pixel array to form the bottom light blocking layer.

In other words, the fingerprint detection unit may include at least one light-blocking layer and a plurality of optical sensing pixels, wherein each of the at least one light-blocking layer is provided with openings corresponding to the plurality of optical sensing pixels. For example, the at least one light-blocking layer may be a multi-layer light-blocking layer, and the top light-blocking layer of the multi-layer light-blocking layer may be provided with at least one opening corresponding to the plurality of optical sensing pixels. For example, one of the small holes in the small hole array in the top light-blocking layer corresponds to at least two optical sensing pixels among the plurality of optical sensing pixels. For example, as shown in FIG12 , the at least one light-blocking layer may include a top light-blocking layer and a bottom light-blocking layer, wherein the top light-blocking layer is provided with four openings 2141 corresponding to four optical sensing pixels, respectively. The bottom light-blocking layer is provided with four openings 213 corresponding to four optical sensing pixels, respectively. For another example, as shown in FIG13 , the at least one light-blocking layer may include a top light-blocking layer and a bottom light-blocking layer, wherein the top light-blocking layer is provided with one opening 2142 corresponding to four optical sensing pixels. The bottom light-blocking layer is provided with four openings 213 corresponding to four optical sensing pixels, respectively.

It should be noted that the openings provided in the light-blocking layer in FIG. 12 and FIG. 13 are only illustrated by taking the fingerprint detection unit shown in FIG. 11 as an example, and the implementation method thereof can be applied to various embodiments of the present application, and the present application does not limit this. For example, the at least one light-blocking layer can be a light-blocking layer having more than two layers. Alternatively, the at least one light-blocking layer can be a light-blocking layer, that is, the at least one light-blocking layer can be a straight hole collimator or a hole collimator having a certain thickness. It should also be understood that FIG. 5 to FIG. 13 are only examples of a microlens being provided above each optical sensing pixel, and should not be understood as a limitation of the present application. For example, the fingerprint detection unit may also include microlenses or optical sensing pixels of other numbers or other arrangements. For example, in another implementation, the at least one microlens is a plurality of rows of microlenses, and the plurality of optical sensing pixels are a plurality of rows of optical sensing pixels corresponding to the plurality of rows of microlenses, wherein each row of optical sensing pixels in the plurality of rows of optical sensing pixels is staggeredly arranged below a corresponding row of microlenses. Optionally, the plurality of rows of microlenses can be a plurality of columns or rows of microlenses. The plurality of rows of optical sensing pixels can be a plurality of columns or rows of optical sensing pixels.

Among them, the at least one light-blocking layer may be provided with a corresponding optical path design so that the multiple rows of microlenses receive the inclined light signals in the multiple directions along the staggered directions of the multiple rows of optical sensing pixels, and each row of microlenses in the multiple rows of microlenses converges the received inclined light signals to the optical sensing pixels under the same row of microlenses or an adjacent row of microlenses.

For example, as shown in FIG. 14 , the fingerprint detection unit 22 may include 4 columns of optical sensing pixels distributed in a rectangular array and 4 columns of microlenses corresponding to the 4 columns of optical sensing pixels, wherein each column of the 4 columns of optical sensing pixels includes 6 optical sensing pixels 221, and each column of the 4 columns of microlenses includes 6 microlenses 222, and one optical sensing pixel 221 is staggered below one microlens 222. The fingerprint detection unit 22 may also include a top light-blocking layer and a bottom light-blocking layer. At this time, for each microlens 222, the top light-blocking layer and the bottom light-blocking layer may be respectively provided with their corresponding openings 2241 and openings 2231. Among them, each microlens 222 in each row of microlenses in the multiple rows of microlenses can converge the received light signal to the optical sensing pixel 221 obliquely below the same microlens 222 through the corresponding openings 2241 and openings 2231. Therefore, when the fingerprint detection device includes a plurality of fingerprint detection units distributed in an array, a plurality of fingerprint images can be generated based on light signals received in multiple directions, thereby obtaining a high-resolution fingerprint image to improve the fingerprint recognition effect.

In other words, the fingerprint detection unit shown in FIG. 14 may include an optical sensing pixel array as shown in FIG. 15 , wherein “1” represents an optical sensing pixel for receiving an oblique light signal in a first direction, and “2” represents an optical sensing pixel for receiving an oblique light signal in a second direction. In other words, the optical sensing pixels represented by “1” and “2” can be used to generate a fingerprint image respectively, that is, a total of 2 fingerprint images can be generated, and these 2 fingerprint images can be used to merge into a high-resolution fingerprint image, thereby improving the recognition effect of the fingerprint detection device. In conjunction with FIG. 14 , based on the order from left to right, the first direction may be the direction of the oblique light signal received by the microlenses in the first and second columns of microlenses, and the second direction may be the direction of the oblique light signal received by the microlenses in the third and fourth columns.

In one embodiment of the present application, the projection of each microlens in each row of microlenses in the multiple rows of microlenses on the plane where the display screen is located is circular, the projection of each optical sensing pixel in each row of optical sensing pixels in the multiple rows of optical sensing pixels on the plane where the display screen is located is rectangular, and the projection of the center of each optical sensing pixel in each row of optical sensing pixels in the multiple rows of optical sensing pixels on the plane where the display screen is located is offset by a preset distance along the misalignment direction of the multiple rows of optical sensing pixels relative to the projection of the center of the corresponding microlens on the plane where the display screen is located, and the preset distance is less than or equal to the side length of the rectangle, or the preset distance is less than or equal to the diameter of the circle. In other words, each row of microlenses in the multiple rows of microlenses is offset by a preset distance along the misalignment direction along the respective misalignment directions. For example, in one implementation, as shown in FIG. 14, the misalignment direction is the diagonal direction of each optical sensing pixel in each row of optical sensing pixels in the multiple rows of optical sensing pixels, that is, each microlens 222 in each row of microlenses in the multiple rows of microlenses is offset by a preset distance along the diagonal direction of the same optical sensing pixel 221. At this time, each optical sensing pixel 221 in each row of the multiple rows of optical sensing pixels may be provided with a corresponding opening 2241 and opening 2231 above, that is, at least one light-blocking layer in the fingerprint detection unit 22 is provided with a corresponding opening above each optical sensing pixel 221. Of course, the misalignment direction may also be the direction in which the vertical side length of each optical sensing pixel in each row of the multiple rows of optical sensing pixels is located. For example, the misalignment direction may also be the direction in which the rows or columns of the optical sensing pixel array are located.

It should be noted that the preset distance may also be an offset distance in the direction where the side length of the optical sensing pixel 221 is located. For example, the two side lengths of the optical sensing pixel 221 are the X-axis direction and the Y-axis direction, wherein the preset distance may include an offset distance along the X-axis direction and an offset distance along the Y-axis direction. For example, assuming that the side length of the optical sensing pixel is 12.5 mm, the diameter of the microlens is 11.5 mm, the offset distance along the X-axis direction may be 4 to 5 mm, and the offset distance along the Y-axis direction may be 4 to 5 mm. Of course, the above parameters are only examples and should not be understood as limitations on themselves. For example, the offset distance along the X-axis direction may not be equal to the offset distance along the Y-axis direction. For another example, the offset distance along the X-axis direction or the offset distance along the Y-axis direction may be greater than 5 mm or less than 4 mm.

With respect to the misalignment direction, in another implementation, as shown in FIG16 , the fingerprint detection unit 22 may include a top light-blocking layer and a bottom light-blocking layer. At this time, for each microlens 222, the top light-blocking layer and the bottom light-blocking layer may be provided with their corresponding openings 2242 and openings 2232, respectively. Among them, each microlens 222 in each row of microlenses in the multiple rows of microlenses can converge the received oblique light signal to the optical sensing pixel 221 directly below the adjacent microlens 222 through the corresponding openings 2242 and openings 2232. For example, the upper left corner microlens 222 can converge the received oblique light signal to the optical sensing pixel 221 directly below the adjacent second row and first column microlens 222. At this time, the bottom light-blocking layer may be provided with its corresponding opening 2232 above each optical sensing pixel 221 in each row of optical sensing pixels in the multiple rows of optical sensing pixels, and the top light-blocking layer may be provided with its corresponding opening 2242 above the optical sensing pixel 221 adjacent to the same optical sensing pixel 221.

It should be understood that the misalignment direction may also be other directions. For example, the misalignment direction is the direction where the horizontal side length of each optical sensing pixel in each row of the multiple rows of optical sensing pixels is located. For another example, the misalignment direction may be the direction where the rows or columns of the multiple rows of optical sensing pixels are located.

In some other embodiments of the present application, the number of the at least one microlens is smaller than the number of the plurality of optical sensing pixels.

In one implementation, the at least one microlens is one microlens, and the plurality of optical sensing pixels are a 2x2 optical sensing pixel rectangular array, wherein the one microlens is disposed directly above the 2x2 optical sensing pixel rectangular array. For example, as shown in FIG17 , the fingerprint detection unit 23 may include one microlens 232 and four optical sensing pixels 231 distributed in a rectangular array.

In a specific optical path design, at least one light-blocking layer in the fingerprint detection unit 23 may be provided with openings corresponding to the four optical sensing pixels 231 respectively below the one microlens, so that the one microlens can receive the inclined light signals in the multiple directions along the diagonal direction of the 2x2 optical sensing pixel rectangular array, and the one microlens can converge the inclined light signals in the multiple directions along the diagonal direction to the optical sensing pixels in the optical sensing pixel rectangular array respectively, so as to increase the amount of signal that each optical sensing pixel can receive, thereby improving the fingerprint recognition effect. For example, as shown in FIG. 18 or FIG. 19, the at least one light-blocking layer may include a top light-blocking layer and a bottom light-blocking layer. The top light-blocking layer is provided with openings 2341 corresponding to the four optical sensing pixels 231 respectively below the one microlens 232, and the bottom light-blocking layer is provided with openings 232 corresponding to the four optical sensing pixels 231 respectively below the one microlens 232. The one microlens 232 converges the received light signals from multiple directions to the four optical sensing pixels 231 through the corresponding openings 2341 and the openings 232. Of course, the four small holes of the top light-blocking layer corresponding to the four optical sensing pixels 231 can also be merged into one large hole, such as the opening 2342 shown in FIG. 20 or FIG. 21.

In another implementation, the one microlens is a 2x2 microlens rectangular array, the multiple optical sensing pixels are a 3x3 optical sensing pixel rectangular array, and a microlens is disposed directly above every 4 adjacent optical sensing pixels in the 3x3 rectangular array. For example, a microlens is disposed directly above the center position of every 4 adjacent optical sensing pixels in the 3x3 rectangular array. For example, as shown in FIG22 , the fingerprint detection unit 24 may include 4 microlenses 242 distributed in a rectangular array and 9 optical sensing pixels 241 distributed in a rectangular array.

In a specific optical path design, as shown in FIG23 , at least one light-blocking layer in the fingerprint detection unit 24 may be provided with openings corresponding to the optical sensing pixels 241 at the four corners of the 3x3 optical sensing pixel rectangular array, so that each microlens 242 in the 2x2 microlens rectangular array can converge the received oblique light signal to the optical sensing pixel 241 at the four corners of the 3x3 optical sensing pixel rectangular array that is closest to the same microlens 424. For example, the at least one light-blocking layer may include a top light-blocking layer and a bottom light-blocking layer. The top light-blocking layer is provided with openings 244 corresponding to the optical sensing pixels 241 at the four corners, and the bottom light-blocking layer is provided with openings 243 corresponding to the optical sensing pixels 241 at the four corners. Thus, the four microlenses 242 can converge the oblique light signals in multiple directions to the optical sensing pixels 241 at the four corners through the corresponding openings 2341 and openings 243.

Since only the optical sensing pixels 241 at the four corners of the 3x3 optical sensing pixel rectangular array will receive the inclined light signals for detecting fingerprint information, in order to increase the utilization rate of the optical sensing pixels, in some embodiments of the present application, a fingerprint detection device including a plurality of fingerprint detection units 24 can be formed by an interlaced arrangement. For example, as shown in FIG24 , the optical sensing pixel 241 between the upper left optical sensing pixel 241 and the upper right optical sensing pixel 241 of the central fingerprint detection unit located in the middle position can be reused as the optical sensing pixel 241 located at the lower left corner of another fingerprint detection unit, the optical sensing pixel 241 between the upper left optical sensing pixel 241 and the lower left optical sensing pixel 241 of the central fingerprint detection unit can be reused as the optical sensing pixel 241 located at the lower right corner of another fingerprint detection unit, the optical sensing pixel 241 between the lower left optical sensing pixel 241 and the lower right optical sensing pixel 241 of the central fingerprint detection unit can be reused as the optical sensing pixel 241 located at the upper right corner of another fingerprint detection unit, and the optical sensing pixel 241 between the lower right optical sensing pixel 241 and the upper right optical sensing pixel 241 of the central fingerprint detection unit can be reused as the optical sensing pixel 241 located at the upper left corner of another fingerprint detection unit.

In other words, the fingerprint detection device may include a plurality of optical sensing pixels as shown in FIG. 25, wherein "0" represents an optical sensing pixel that is not used to receive light signals, "1", "2", "3" and "4" represent optical sensing pixels used to receive light signals in four different directions, and blank spaces represent optical sensing pixels that can be reused as other fingerprint detection units. In other words, the optical sensing pixels represented by "1", "2", "3" and "4" can be used to generate a fingerprint image respectively, that is, a total of four fingerprint images can be generated, and these four fingerprint images can be used to merge into a high-resolution fingerprint image, thereby improving the recognition effect of the fingerprint detection device.

In another implementation, the at least one microlens is a 3x3 microlens rectangular array, the multiple optical sensing pixels are a 4x4 optical sensing pixel rectangular array, and a microlens is disposed directly above every 4 adjacent optical sensing pixels in the 4x4 optical sensing pixel rectangular array. For example, as shown in FIG26 , the fingerprint detection unit 25 may include 9 microlenses 252 distributed in a rectangular array and 16 optical sensing pixels 251 distributed in a rectangular array. Among them, a microlens 252 is disposed directly above every 4 adjacent optical sensing pixels 251 in the 16 optical sensing pixels 251.

In a specific optical path design, at least one light-blocking layer in the fingerprint detection unit 25 may be respectively provided with openings corresponding to the 16 optical sensing pixels 251, so that the central microlens in the 3x3 microlens rectangular array converges the received oblique light signal to the 4 optical sensing pixels below the central microlens, each of the microlenses at the 4 corners in the 3x3 microlens rectangular array converges the received oblique light signal to the optical sensing pixel located at the corner of the 4x4 optical sensing pixel rectangular array below the same microlens, and each of the other microlenses in the 3x3 microlens rectangular array converges the received oblique light signal to the two outer optical sensing pixels below the same microlens. For example, as shown in FIG27, the at least one light-blocking layer may include a top light-blocking layer and a bottom light-blocking layer. The top light-blocking layer is provided with openings 2541 corresponding to the 16 optical sensing pixels 251, and the bottom light-blocking layer is provided with openings 253 corresponding to the 16 optical sensing pixels 251. Thus, the nine microlenses 252 can respectively converge the inclined light signals in the multiple directions to the 16 optical sensing pixels 251 through the corresponding openings 2341 and openings 243 .

In other words, the fingerprint detection device may include a plurality of optical sensing pixels as shown in FIG. 28, wherein "1", "2", "3" and "4" respectively represent optical sensing pixels for receiving 4 different directions. In other words, the optical sensing pixels represented by "1", "2", "3" and "4" can be used to generate a fingerprint image respectively, that is, a total of 4 fingerprint images can be generated, and these 4 fingerprint images can be used to merge into a high-resolution fingerprint image, thereby improving the recognition effect of the fingerprint detection device.

Of course, FIG. 27 is merely an example of the present application and should not be construed as a limitation to the present application.

For example, as shown in FIG29 , the two small holes corresponding to the two optical sensing pixels 251 located between the two corners in the 4x4 optical sensing pixel rectangular array in the top light blocking layer can be merged into one large hole, and the four small holes corresponding to the four adjacent optical sensing pixels 251 located at the center position in the 4x4 optical sensing pixel rectangular array in the top light blocking layer can be merged into one large hole, so as to reduce the processing difficulty and increase the amount of converged light signals, thereby improving the fingerprint recognition effect of the fingerprint detection device.

The above describes the fingerprint detection units that can be staggered in arrangement. The following describes the fingerprint detection units that are staggered in the optical path structure.

For example, the fingerprint detection device may include a plurality of fingerprint detection units distributed in an array or staggered, each of the plurality of fingerprint detection units may include a microlens, at least one light-blocking layer and a plurality of optical sensing pixels, each of the at least one light-blocking layer is provided with openings corresponding to the plurality of optical sensing pixels, and the at least one light-blocking layer is arranged between the one microlens and the plurality of optical sensing pixels. The microlenses in the plurality of fingerprint detection units may converge the received inclined light signals to the optical sensing pixels in the adjacent plurality of fingerprint detection units. In other words, the plurality of optical sensing pixels in each fingerprint detection unit in the fingerprint detection device are used to receive the inclined light signals converged by the microlenses in the adjacent plurality of fingerprint detection units. For ease of description, the plurality of staggered fingerprint detection units are explained below from the perspective of the fingerprint detection device.

FIG. 30 is a schematic top view of a fingerprint detection device 30 according to an embodiment of the present application, and FIG. 31 is a side sectional view of the fingerprint detection device 30 shown in FIG. 30 along the BB′ direction.

As shown in FIG30 , the fingerprint detection device 30 may include 3x3 fingerprint detection units, wherein each of the 3x3 fingerprint detection units includes a microlens and a 2x2 rectangular array of optical sensing pixels located below the microlens. Taking the middle fingerprint detection unit located in the middle of the 3x3 fingerprint detection units as an example, the 2x2 rectangular array of optical sensing pixels in the middle fingerprint detection unit is used to receive the inclined light signals converged by the microlenses in the fingerprint detection units located at the four corners of the 3x3 fingerprint detection units. In other words, the microlens in the central fingerprint detection unit located at the center of the 3x3 fingerprint detection unit rectangular array is used to converge the received inclined light signals in multiple directions along the diagonal direction of the 3x3 fingerprint detection unit rectangular array to the optical sensing pixels in the adjacent fingerprint detection units close to the central fingerprint detection unit.

As shown in FIG31 , the fingerprint detection device 30 may include a microlens array 310, at least one light-blocking layer, and an optical sensing pixel array 340. The microlens array 310 may be used to be arranged below the display screen of the electronic device, the at least one light-blocking layer may be arranged below the microlens array 310, and the optical sensing pixel array 340 may be arranged below the at least one light-blocking layer. Among them, the microlens array 310 and the at least one light-blocking layer may be the light-guiding structure included in the optical component 132 shown in FIG3 or FIG4 , and the optical sensing pixel array 340 may be the sensing array 133 having a plurality of optical sensing units 131 (also referred to as optical sensing pixels, photosensitive pixels, pixel units, etc.) shown in FIG1 to FIG4 , and will not be described in detail here to avoid repetition.

The microlens array 310 includes a plurality of microlenses. For example, the microlens array 310 may include a first microlens 311, a second microlens 312, and a third microlens 313. The at least one light-blocking layer may include a plurality of light-blocking layers, for example, the at least one light-blocking layer may include a first light-blocking layer 320 and a second light-blocking layer 330. The optical sensing pixel array 340 may include a plurality of optical sensing pixels, for example, the optical sensing pixel array may include a first optical sensing pixel 341, a second optical sensing pixel 342, a third optical sensing pixel 343, a fourth optical sensing pixel 344, a fifth optical sensing pixel 345, and a sixth optical sensing pixel 346. At least one opening corresponding to each of the plurality of microlenses (i.e., the first microlens 311, the second microlens 312, and the third microlens 313) is respectively provided in the first light-blocking layer 320 and the second light-blocking layer 330. For example, the first light-blocking layer 320 is provided with a first opening 321 and a second opening 322 corresponding to the first microlens 311, the first light-blocking layer 320 is also provided with a second opening 322 and a third opening 323 corresponding to the second microlens 312, and the first light-blocking layer 320 is provided with a third opening 323 and a fourth opening 324 corresponding to the third microlens 313. Similarly, the second light-blocking layer 330 is provided with a fifth opening 331 and a sixth opening 332 corresponding to the first microlens 311, the second light-blocking layer 330 is also provided with a seventh opening 333 and an eighth opening 334 corresponding to the second microlens 312, and the second light-blocking layer 330 is provided with a ninth opening 335 and a tenth opening 336 corresponding to the third microlens 313.

In the specific optical path design, a plurality of optical sensing pixels are arranged under each microlens in the microlens array 310. The plurality of optical sensing pixels arranged under each microlens are respectively used to receive light signals converged by a plurality of adjacent microlenses. Taking the second microlens 312 as an example, a third optical sensing pixel 343 and a fourth optical sensing pixel 344 may be arranged under the second microlens 312, wherein the third optical sensing pixel 343 may be used to receive an inclined light signal converged by the first microlens 311 and passing through the second opening 322 and the seventh opening 333, and the fourth optical sensing pixel 344 may be used to receive an inclined light signal converged by the third microlens 313 and passing through the third opening 323 and the eighth opening 334.

In other words, the at least one light-blocking layer is formed with a plurality of light-guiding channels corresponding to each microlens in the microlens array 310, and the bottoms of the plurality of light-guiding channels corresponding to each microlens extend to the bottom of the adjacent plurality of microlenses, respectively. Taking the second microlens 312 as an example, the plurality of light-guiding channels corresponding to the second microlens 312 may include a light-guiding channel formed by the second opening 322 and the sixth opening 332, and a light-guiding channel formed by the third opening 323 and the ninth opening 335. The light-guiding channel formed by the second opening 322 and the sixth opening 332 extends to the bottom of the first microlens 311, and the light-guiding channel formed by the third opening 323 and the ninth opening 335 extends to the bottom of the third microlens 313. An optical sensing pixel may be provided below each of the plurality of light-guiding channels corresponding to each microlens in the microlens array 310. Taking the second microlens 312 as an example, a second optical sensing pixel 342 is disposed below the light guide channel formed by the second opening 322 and the sixth opening 332 , and a fifth optical sensing pixel 345 is disposed below the light guide channel formed by the third opening 323 and the ninth opening 335 .

By rationally designing multiple light-guiding channels corresponding to each microlens, the optical sensing pixel array 340 can receive tilted light signals in multiple directions, and converge the tilted light signals in multiple directions through a single microlens, which can solve the problem of long exposure time of the single object-space telecentric microlens array solution. In other words, the fingerprint detection device 30 can not only solve the problem of poor recognition effect of vertical light signals on dry fingers and the problem of long exposure time of the single object-space telecentric microlens array solution, but also solve the problems of excessive thickness, poor tolerance and excessive size.

It should be understood that the embodiment of the present application does not specifically limit the arrangement and size of the optical sensing pixel array. For example, the fingerprint detection unit may include a plurality of optical sensing pixels distributed in a polygonal (eg, diamond), circular or elliptical shape.

Please continue to refer to FIG. 31 , the fingerprint detection device 30 may further include a transparent medium layer 350 .

The transparent medium layer 350 may be disposed at least one of the following positions: between the microlens array 310 and the at least one light-blocking layer; between the at least one light-blocking layer; and between the at least one light-blocking layer and the optical sensing pixel array 340. For example, the transparent medium layer 350 may include a first medium layer 351 between the microlens array 310 and the at least one light-blocking layer (i.e., the first light-blocking layer 320) and a second medium layer 352 between the first light-blocking layer 320 and the second light-blocking layer 330.

The material of the transparent medium layer 350 can be any transparent material that is transparent to light, such as glass, or can be a transition of air or vacuum, which is not specifically limited in the present application.

The above describes a fingerprint detection device for receiving inclined light signals in four directions, but the embodiments of the present application are not limited thereto. The fingerprint detection device can also be used to receive inclined light signals in two or three directions to achieve the beneficial effects mentioned above.

In some embodiments of the present application, the fingerprint detection device is suitable for use under a display screen to realize under-screen optical fingerprint detection. The fingerprint detection device includes a plurality of fingerprint detection units distributed in an array or staggered. Each of the plurality of fingerprint detection units includes at least one microlens, at least one light-blocking layer below the at least one microlens, and a plurality of optical sensing pixels below the at least one light-blocking layer.

Among them, the at least one microlens is arranged above the multiple optical sensing pixels; the at least one light-blocking layer is arranged between the at least one microlens and the multiple optical sensing pixels, and each of the at least one light-blocking layer is provided with openings corresponding to the multiple optical sensing pixels; the inclined light signals in 2M directions reflected from the finger above the display screen are converged by the at least one microlens, and then transmitted to the multiple optical sensing pixels respectively through the openings provided in the at least one light-blocking layer, and the inclined light signals are used to detect the fingerprint information of the finger, and M is a positive integer.

In some embodiments of the present application, the 2M directions include a first direction and a second direction, and a projection of the first direction on the display screen is perpendicular to a projection of the second direction on the display screen.

Typically, fingerprints contain raised ridges and sunken valleys. Optical fingerprint systems rely on light reflected from the fingerprint surface to form images. As shown in Figure 32, when the incident light is perpendicular to the fingerprint direction, the reflected light from the valley will be blocked by the side of the ridge, making the difference between the ridge and the valley more obvious. As shown in Figure 33, when the incident light is parallel to the fingerprint direction, the reflected light from the valley will not be blocked by the side of the ridge, and the difference between the ridge and the valley is not obvious. If the light collection direction is a single direction, since the direction of pressing the fingerprint is random, the pressed fingerprint is likely to be parallel to the light collection direction. At this time, the fingerprint signal is very poor and may be difficult to identify. The multi-directional light collection solution collects signal light at different angles. Taking orthogonal bidirectional light collection as an example, if one direction receives the worst signal (parallel to the fingerprint direction), the other direction must receive the best signal (perpendicular to the fingerprint direction). The multi-directional (bidirectional) light collection solution can receive a relatively good signal when the fingerprint is pressed randomly, thereby improving the fingerprint recognition ability.

In some embodiments of the present application, a projection of the first direction or the second direction on the display screen is perpendicular to a polarization direction of the display screen.

Typically, the display screen of an electronic device is an OLED screen, which has polarization characteristics, and the angle between its polarization direction and the horizontal (or vertical) direction of the screen is 45 degrees or 135 degrees. For example, the polarization direction 361 shown in Figure 34 or the polarization direction 366 shown in Figure 35. The polarization characteristics of the OLED screen make the signal amount of the fingerprint different with the angle between the incident surface and the polarization direction. The signal amount is the largest when the incident surface is perpendicular to the polarization direction, and the signal amount is the smallest when the incident surface is parallel to the polarization direction. In other words, the best light receiving direction of the screen with a polarization direction of 45 degrees is exactly the worst light receiving direction of the screen with a polarization direction of 135 degrees.

Therefore, in order to ensure that both screens can be used, the single light receiving direction solution can only select a direction of 45 degrees or 135 degrees from the optimal light receiving direction as the light receiving direction. For example, as shown in FIG34 or FIG35 , the light receiving direction of the fingerprint detection device 362 is direction 363 or the opposite direction of direction 363.

For the multi-directional light receiving solution, taking the orthogonal four-directional or two-way light receiving solution as an example, since the signal light in four (two) directions can be received at the same time, the signal light in the best direction can be received under the 45° and 135° screens. For example, as shown in FIG36, the light receiving directions of the fingerprint detection device 362 are direction 364 and direction 365. For another example, as shown in FIG37, the light receiving directions of the fingerprint detection device 362 are direction 364, direction 365, the opposite direction of direction 364, and the opposite direction of direction 365.

From another perspective, those skilled in the art may design an arrangement of the plurality of optical sensing pixels based on the first direction or the second direction.

For example, the plurality of optical sensing pixels form an optical sensing pixel rectangular array, and a projection of the first direction or the second direction on the optical sensing pixel rectangular array is parallel to a diagonal direction of the optical sensing pixel rectangular array.

In some embodiments of the present application, the at least one microlens is one microlens, the multiple optical sensing pixels are the first column of optical sensing pixels in a 2x2 optical sensing pixel matrix array, the one microlens is located above the center of the 2x2 optical sensing pixel matrix array, and the second column of optical sensing pixels in the 2x2 optical sensing pixel matrix array is multiplexed as optical sensing pixels in the first column of optical sensing pixels in other fingerprint detection units. Optionally, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 2x2 optical sensing pixel matrix array are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 2x2 optical sensing pixel matrix array.

In other words, the multiple optical sensing pixels are a 2x2 optical sensing pixel rectangular array, and the openings of the at least one light blocking layer enable the optical sensing pixels in the first row and first column and the optical sensing pixels in the second row and second column in the 2x2 optical sensing pixel rectangular array to receive inclined light signals along a diagonal direction of the 2x2 optical sensing pixel rectangular array, and the openings of the at least one light blocking layer also enable the optical sensing pixels in the first row and second column and the optical sensing pixels in the second row and first column in the 2x2 optical sensing pixel rectangular array to receive inclined light signals along another diagonal direction of the 2x2 optical sensing pixel rectangular array.

For example, as shown in FIG38, the fingerprint detection unit 26 may include a microlens 262 and two optical sensing pixels 261 on the left side of four optical sensing pixels 261 distributed in a rectangular array, wherein the two optical sensing pixels 261 on the left side are used to receive the inclined light signals in two directions converged by the one microlens 262. At this time, in terms of the optical path design, as shown in FIG38, the fingerprint detection unit 26 may include a top light-blocking layer and a bottom light-blocking layer. Among them, the top light-blocking layer may include two openings 262 corresponding to the two optical sensing pixels 261 on the left side, respectively, and the bottom light-blocking layer may include two openings 263 corresponding to the two optical sensing pixels 261 on the left side. Optionally, the two openings 262 in the top light-blocking layer may be merged into one large hole.

In other words, the at least one microlens is one microlens, the multiple optical sensing pixels are two optical sensing pixels, the one microlens is located above the symmetry axis of the two optical sensing pixels, and the opening of the at least one light blocking layer enables the two optical sensing pixels to receive inclined light signals in two directions respectively. For example, the one microlens is located above the center position of the long sides of the two optical sensing pixels. Optionally, two adjacent fingerprint detection units in the fingerprint detection device are offset by one optical sensing pixel in the arrangement direction of the two optical sensing pixels to reasonably design the microlens in the fingerprint detection device.

For example, as shown in FIG. 39 , each fingerprint detection unit in the fingerprint detection device may include a microlens 262 and two optical sensing pixels 261 corresponding to the microlens.

In other words, the at least one microlens is three microlenses, a first microlens among the three microlenses is located above the center position of the 2x2 optical sensing pixel rectangular array, a second microlens among the three microlenses is located above a corner of the first row and second column optical sensing pixels in the 2x2 optical sensing pixel array that is away from the center position, and a third microlens among the three microlenses is located above a corner of the second row and second column optical sensing pixels in the 2x2 optical sensing pixel array that is away from the center position, and the second microlens or the third microlens can be reused as the first microlens of an adjacent fingerprint detection unit.

For example, as shown in FIG40 , each fingerprint detection unit in the fingerprint detection device may include three microlenses 262 and four optical sensing pixels 261 (i.e., a 2x2 optical sensing pixel 261 array) corresponding to the three microlenses 262. Among them, one microlens 262 of the three microlenses 262 is located above the center position of the 2x2 optical sensing pixel 261 array; the other two microlenses 262 of the three microlenses 262 are arranged above two adjacent corners of the four corners of the 2x2 optical sensing pixel 261 array. The microlens 262 located above the center position is used to converge the received light signal to the optical sensing pixels 261 to which the other two corners of the four corners belong, and the other two microlenses 262 are respectively used to converge the received light signal to the optical sensing pixels 261 at the two corners.

Optionally, the other two microlenses 262 may also be reused as microlenses located above the center of the optical sensing pixel array in other fingerprint detection units.

The fingerprint detection device may include multiple fingerprint detection units (such as the fingerprint detection units shown in Figures 38 to 40). By reasonably designing the arrangement of the multiple fingerprint detection units, the size of the fingerprint detection device can be reduced.

For example, as shown in FIG41, the fingerprint detection device may include a plurality of complete fingerprint detection units and a plurality of incomplete fingerprint detection units. The complete fingerprint detection unit includes a microlens and two optical sensing pixels, and the incomplete fingerprint detection unit includes a microlens and an optical sensing pixel. In other words, as shown in FIG42, the fingerprint detection device may include a plurality of optical sensing pixels for receiving oblique light signals in direction 1 and a plurality of optical sensing pixels for receiving oblique light signals in direction 2, wherein "1" and "2" respectively represent optical sensing pixels for receiving two different directions. In other words, the optical sensing pixels represented by "1" and "2" can be used to generate a fingerprint image respectively, that is, a total of two fingerprint images can be generated, and these two fingerprint images can be used to merge into a high-resolution fingerprint image, thereby improving the recognition effect of the fingerprint detection device. Further, for the complete fingerprint detection unit, the two small-sized openings for the two optical sensing pixels in the top light-blocking layer can be merged into a large-sized opening. Optionally, as shown in FIG43, the large-sized opening can be an elliptical opening or other polygonal opening. For example, a rectangular opening.

In order to receive the tilted signal light, there needs to be a certain displacement between the microlens and the photosensitive unit in the fingerprint detection unit. When the light receiving direction is a single direction, the photosensitive unit can be translated in the corresponding direction for a certain distance so that the signal light falls on the center of the photosensitive unit. For example, as shown in FIG44, if the microlens 371 in the fingerprint detection device 370 converges the tilted light signal in a single direction to the optical sensing pixel 372, optionally, as shown in FIG45, each microlens 371 in the fingerprint detection device 370 moves in the direction of the side length of the optical sensing pixel 372. At this time, the offset range of the light spot area 3721 is the length d1 of the side length of the optical sensing pixel 372.

When the fingerprint detection device needs to receive inclined light in different directions at the same time, as shown in FIG. 46, the microlens 371 in the fingerprint detection device 370 can converge the inclined light signal in one direction to the corresponding optical sensing pixel 372, and the other microlens 373 can converge the inclined light signal in another direction to the corresponding optical sensing pixel 372. At this time, in one implementation, as shown in FIG. 46, the microlens 371 and the microlens 373 are both arranged above the center position of the optical sensing pixel 372, so that the signal light is separated from the illumination position of the optical sensing pixel 372 and the center position of the optical sensing pixel 372 by a certain distance d2. In another implementation, as shown in FIG. 47, each microlens 371 and each microlens 373 in the fingerprint detection device 370 moves in the direction where the diagonal of the optical sensing pixel 372 is located. At this time, the offset range of the light spot area 3721 is the length d3 of the diagonal of the optical sensing pixel 372.

In other words, when the fingerprint detection device needs to receive inclined light in different directions at the same time, in one implementation, each microlens in the fingerprint detection unit moves along the direction of the diagonal of the optical sensing pixel. In another implementation, the center position of the light spot area in the fingerprint detection device moves along the direction of the diagonal of the optical sensing pixel. For example, the angle between the offset direction of the microlens and the side length of the optical sensing pixel in the four-way and two-way light collection schemes is 45 degrees. When there is a certain offset between the light spot area and the center position of the optical sensing pixel, the light spot area that moves diagonally in the optical sensing pixel has a higher tolerance for the offset than the horizontally or vertically moving light spot area.

In some embodiments of the present application, the at least one microlens is one microlens, the multiple optical sensing pixels are the first row and first column optical sensing pixels and the fourth row and first column optical sensing pixels in the first column optical sensing pixels in the 4x2 optical sensing pixel matrix array, the one microlens is located above the center position of the side length of the second column optical sensing pixels in the 4x2 optical sensing pixel matrix array away from the first column optical sensing pixels, and the optical sensing pixels in the 4x2 optical sensing pixel matrix array except the first row and first column optical sensing pixels and the fourth row and first column optical sensing pixels are reused as optical sensing pixels in other fingerprint detection units. Optionally, two fingerprint detection units adjacent in the row direction of the 4x2 optical sensing pixel matrix array in the fingerprint detection device are offset by one optical sensing pixel in the column direction of the 4x2 optical sensing pixel matrix array. For example, in conjunction with FIG. 48, the second row and first column optical sensing pixels in the 4x2 optical sensing pixel matrix array can be reused as the first row and first column optical sensing pixels in the adjacent fingerprint detection units in the row direction.

For example, as shown in FIG48 , the fingerprint detection unit 27 includes a microlens 272 and two optical sensing pixels 271 (i.e., the upper left optical sensing pixel 271 and the lower left optical sensing pixel 271 in the 4×2 optical sensing pixel 271 matrix array). The two openings 274 corresponding to the two optical sensing pixels 271 in the top light blocking layer and the two openings 273 corresponding to the two optical sensing pixels 271 in the bottom light blocking layer enable the microlens 272 to converge the received light signals to the two optical sensing pixels 271.

In other words, the at least one microlens is three microlenses, the multiple optical sensing pixels are the first column of optical sensing pixels in the 4x2 optical sensing pixel matrix array, and the three microlenses are evenly distributed above the side length of the second column of optical sensing pixels in the 4x2 optical sensing pixel matrix array away from the first column of optical sensing pixels. Optionally, two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 4x2 optical sensing pixel matrix array are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 4x2 optical sensing pixel matrix array.

For example, as shown in FIG49, one microlens 272 of the three microlenses is located above the center of the side length of the second column of optical sensing pixels in the 4x2 optical sensing pixel matrix array away from the first column of optical sensing pixels, and the other two microlenses 272 of the three microlenses are respectively located above the two ends of the side length of the second column of optical sensing pixels in the 4x2 optical sensing pixel matrix array away from the first column of optical sensing pixels.

In other words, the at least one microlens is four microlenses, the plurality of optical sensing pixels is a 2x2 optical sensing pixel matrix array, the optical sensing pixels in the 2x2 optical sensing pixel rectangular array are located at the first and second columns in the second and third rows of the 4x3 optical sensing pixel rectangular array, wherein two of the four microlenses are respectively located above two corners of the four corners of the 2x2 optical sensing pixel rectangular array close to the third column of the 4x3 optical sensing pixel rectangular array, and the other two microlenses are respectively located above two corners of the four corners of the 4x3 optical sensing pixel rectangular array away from the center of the 2x2 optical sensing pixel rectangular array along the diagonal direction of the 2x2 optical sensing pixel rectangular array. Optionally, the optical sensing pixels in the 4x3 optical sensing pixel rectangular array other than the 2x2 optical sensing pixel rectangular array are multiplexed as optical sensing pixels in the 2x2 optical sensing pixel rectangular array in the adjacent fingerprint detection unit for receiving inclined light signals.

For example, as shown in FIG50 , the microlens 272 at the upper right corner converges the received light signal along the diagonal direction of the optical sensing pixel 271 to the second row and second column of the optical sensing pixel 271. The microlens 272 at the lower right corner converges the received light signal along the diagonal direction of the optical sensing pixel 271 to the third row and second column of the optical sensing pixel 271. The microlens 272 at the upper left corner can converge the received light signal along the diagonal direction of the optical sensing pixel 271 to the third row and first column of the optical sensing pixel 271. The microlens 272 at the lower left corner can converge the received light signal along the diagonal direction of the optical sensing pixel 271 to the second row and first column of the optical sensing pixel 271.

Alternatively, the upper left corner microlens 272 may converge the received light signal along the diagonal direction of the optical sensing pixel 271 to the optical sensing pixel 271 at other positions (for example, the optical sensing pixel 271 in the third row and the first column).

In some embodiments of the present application, multiple rows of microlenses in multiple fingerprint detection units in the fingerprint detection device are staggered. For example, the fingerprint detection device includes multiple rows of microlenses, and two adjacent rows of microlenses in the multiple rows of microlenses are staggered.

For example, as shown in FIG. 51 , the fingerprint detection device may include multiple complete and multiple incomplete fingerprint detection units as shown in FIG. 48 . The complete fingerprint detection unit includes a microlens and two optical sensing pixels, and the incomplete fingerprint detection unit includes a microlens and an optical sensing pixel. In other words, as shown in FIG. 52 , the optical sensing pixels in the fingerprint detection device adjacent to the optical sensing pixels for receiving the inclined light signal in direction 1 are all multiple optical sensing pixels for receiving the inclined light signal in direction 2, so that the optical sensing pixels in the optical sensing pixel array are evenly distributed, thereby improving the recognition effect of the fingerprint detection device. Furthermore, for the complete fingerprint detection unit, the two small-sized openings for the two optical sensing pixels in the top light-blocking layer can be merged into a large-sized opening. Optionally, as shown in FIG. 53 , the large-sized opening can be an elliptical opening or other polygonal opening. For example, a rectangular opening.

For another example, as shown in FIG54, the fingerprint detection device may include four fingerprint detection units as shown in FIG50. Optionally, as shown in FIG55, the optical sensing pixels for receiving inclined light signals in two directions in the four fingerprint detection units may be distributed in an array. Optionally, as shown in FIG56, two adjacent fingerprint detection units may share a microlens (i.e., a shared microlens), and the shared microlens corresponds to a large-sized opening in the at least one light-blocking layer.

In some embodiments of the present application, the multiple optical sensing pixels are a 4x4 optical sensing pixel rectangular array, and the 4x4 optical sensing pixel rectangular array includes 4 2x2 optical sensing pixel rectangular arrays distributed in an array, wherein the 2x2 optical sensing pixel rectangular array in the first column and first row and the 2x2 optical sensing pixel rectangular array in the second row and second column of the 4x4 optical sensing pixel rectangular array are used to receive inclined light signals in one direction, and the 2x2 optical sensing pixel rectangular array in the first column and second row and the 2x2 optical sensing pixel rectangular array in the first row and second column of the 4x4 optical sensing pixel rectangular array are used to receive inclined light signals in another direction.

In other words, the microlens corresponding to the same optical sensing pixel is offset in the opposite direction of the inclined light direction received by each optical sensing pixel in the fingerprint detection unit. Optionally, when the positions of the microlenses corresponding to multiple optical sensing pixels overlap after being offset, the microlenses corresponding to the multiple optical sensing pixels may be merged into a large-size microlens. For example, when the positions of the microlenses corresponding to the multiple optical sensing pixels completely overlap after being offset, the multiple optical sensing pixels may directly correspond to one microlens. Optionally, when the multiple optical sensing pixels correspond to one microlens, the multiple small-sized openings corresponding to the multiple optical sensing pixels in the top light blocking layer of the at least one light blocking layer may also be merged into a large-sized opening. Optionally, the top light blocking layer of the at least one light blocking layer is provided with an opening corresponding to each optical sensing pixel.

As an example, the at least one microlens includes a 3x2 microlens rectangular array and two 2x2 microlens rectangular arrays, the 3x2 microlens rectangular array is located above the first to third columns of optical sensing pixels in the 4x4 optical sensing pixel rectangular array, the two 2x2 microlens rectangular arrays are respectively located above the first and fourth rows of optical sensing pixels in the fourth column of optical sensing pixels in the 4x4 optical sensing pixel rectangular array, and the four microlenses in each of the two 2x2 microlens rectangular arrays are respectively located above the four corners of the corresponding optical sensing pixels, so that the 2x2 optical sensing pixel rectangular array in the first column and first row and the 2x2 optical sensing pixel rectangular array in the second row and second column of the 4x4 optical sensing pixel rectangular array receive an inclined light signal in one diagonal direction of the 4x4 optical sensing pixel rectangular array, and the 2x2 optical sensing pixel rectangular array in the first column and second row and the 2x2 optical sensing pixel rectangular array in the first row and second column of the 4x4 optical sensing pixel rectangular array receive an inclined light signal in another diagonal direction. Optionally, the microlenses in the two 2x2 microlens rectangular arrays that are located above the side length of the 4x4 optical sensing pixel rectangular array are reused as microlenses in other fingerprint detection units.

For example, as shown in FIG57, the array of optical sensing pixels 281 in the fingerprint detection unit 28 is used to receive the oblique light signals in the two diagonal directions of the array. Each microlens 282 in the fingerprint detection unit 28 moves a certain distance in the opposite direction of the converged oblique light signal. For example, the certain distance can be half the length of the diagonal of the optical sensing pixel 281. Wherein each light-blocking layer in the fingerprint detection unit 28 can be provided with an opening for each optical sensing pixel 281. In other words, as shown in FIG58, the fingerprint detection device may include 4 2x2 optical sensing pixel arrays distributed in an array, wherein the 2x2 optical sensing pixel arrays in the two diagonal directions are respectively used to receive oblique light signals in two directions. Optionally, as shown in FIG59, when multiple optical sensing pixels 281 correspond to one microlens 282, a large-size opening can be provided in the top light-blocking layer of the at least one light-blocking layer for the multiple optical sensing pixels 281. Optionally, as shown in FIG60, the optical sensing pixels 281 in the multiple fingerprint detection units 28 are continuously distributed in an array.

As another example, each optical sensing pixel in the 4x4 optical sensing pixel rectangular array is used to receive the light signal converged by the microlens above the adjacent optical sensing pixel, so that the first column and first row of the 2x2 optical sensing pixel rectangular array and the second row and second column of the 4x4 optical sensing pixel rectangular array receive the inclined light signal in the direction of one side length of the 4x4 optical sensing pixel rectangular array, and the first column and second row of the 2x2 optical sensing pixel rectangular array and the first row and second column of the 4x4 optical sensing pixel rectangular array receive the inclined light signal in the direction of another side length adjacent to the one side length. Optionally, it is characterized in that the microlens located above the outer area of the 4x4 optical sensing pixel rectangular array in the at least one microlens is reused as a microlens in other fingerprint detection units.

For example, as shown in FIG61 , the array of optical sensing pixels 281 in the fingerprint detection unit 28 is used to receive oblique light signals in the direction of two adjacent side lengths of the array. Each microlens 282 in the fingerprint detection unit 28 moves a certain distance in the opposite direction of the converged oblique light signal. For example, the certain distance may be the length of the side length of the optical sensing pixel 281. Each light blocking layer in the fingerprint detection unit 28 may be provided with an opening for each optical sensing pixel 281. Optionally, as shown in FIG62 , the fingerprint detection device may include a plurality of fingerprint detection units 28, and the optical sensing pixels 281 in the plurality of fingerprint detection units 28 are continuously distributed in an array.

In some embodiments of the present application, the multiple optical sensing pixels are multiple rows of optical sensing pixels, at least one row of first optical sensing pixels among the multiple rows of optical sensing pixels is used to receive inclined light signals in one direction, and at least one row of second optical sensing pixels among the multiple rows of optical sensing pixels is used to receive inclined light signals in another direction.

In other words, when the fingerprint detection device includes a plurality of fingerprint detection units distributed in an array, the fingerprint detection device includes an optical sensing pixel array distributed in an array, at least one row or one column in the optical sensing pixel array is used to receive an inclined light signal in one direction, and the remaining rows or columns are used to receive an inclined light signal in another direction.

As an example, each optical sensing pixel in the multiple rows of optical sensing pixels is used to receive the light signal converged by the microlens above the adjacent optical sensing pixel, so that the at least one row of first optical sensing pixels receives the inclined light signal along the arrangement direction of the optical sensing pixels, and the at least one row of second optical sensing pixels receives the inclined light signal along the direction perpendicular to the arrangement direction of the optical sensing pixels.

For example, as shown in FIG63 , the fingerprint detection unit 29 includes a 4×4 optical sensing pixel 291 array, and each optical sensing pixel 291 in the 4×4 optical sensing pixel 291 array is used to receive the light signal converged by the microlens 292 above the adjacent optical sensing pixel 291. The bottom light blocking layer in the at least one light blocking layer is provided with an opening 264 corresponding to each optical sensing pixel 291, and the top light blocking layer in the at least one light blocking layer is provided with an opening 263 corresponding to each optical sensing pixel 291. In other words, as shown in FIG64 , the first and second rows of the fingerprint detection unit 29 are used to receive inclined light signals in the horizontal direction, and the third and fourth rows of the fingerprint detection unit 29 are used to receive inclined light signals in the vertical direction.

As another example, the at least one microlens is a 3x1 microlens rectangular array, the multiple optical sensing pixels are the first column of optical sensing pixels in a 4x2 optical sensing pixel rectangular array, the 3x1 microlens rectangular array is located above the 4x2 optical sensing pixel rectangular array, and the second column of optical sensing pixels in the 4x2 optical sensing pixel rectangular array is multiplexed as optical sensing pixels in other fingerprint detection units.

For example, as shown in FIG65, through three microlenses 292, the first and second rows of optical sensing pixels 291 of the 3x1 microlens rectangular array receive light signals in a diagonal direction, and the third and fourth rows of optical sensing pixels 291 of the 3x1 microlens rectangular array receive light signals in another diagonal direction. Similarly, the top light-blocking layer in the at least one light-blocking layer is provided with four openings 294 corresponding to the 3x1 microlens rectangular array, and the bottom light-blocking layer in the at least one light-blocking layer is provided with four openings 293 corresponding to the 3x1 microlens rectangular array. Optionally, the fingerprint detection device may include a plurality of fingerprint detection units 29 distributed in an array. For example, as shown in FIG66, the fingerprint detection device may include 4 fingerprint detection units 29. Optionally, as shown in FIG67, a large-size opening in the top light-blocking layer corresponds to the second and third rows of optical sensing pixels 291 in the 3x1 microlens rectangular array.

The above introduces the structure of the fingerprint detection unit or the fingerprint detection device. For example, the structure of the fingerprint detection unit or the fingerprint detection device is expected to be constructed based on the transmission of optical signals. During the manufacturing process, mass production is required based on specific design parameters. The specific design parameters of the fingerprint detection device are exemplified below.

Figure 68 is a schematic structural diagram of the fingerprint detection device of an embodiment of the present application. For ease of understanding, the following structural diagram 68 illustrates the design parameters of the fingerprint detection device.

As an example, the fingerprint detection device includes a microlens array, Z light-blocking layers located below the microlens array, and an optical sensing pixel array located below the Z light-blocking layers, where Z is a positive integer. The microlens array is used to be arranged below the display screen; the Z light-blocking layers are arranged below the microlens array, and each of the Z light-blocking layers is provided with a small hole array; the optical sensing pixel array is arranged below the small hole array of the bottom light-blocking layer among the Z light-blocking layers.

It should be understood that the fingerprint detection device and the microlens array, the Z light-blocking layers, and the optical sensing pixel array in the fingerprint detection device can refer to the relevant descriptions in the above text, and will not be repeated here to avoid repetition.

As shown in FIG. 68 , the microlens array may include a plurality of microlenses 411, the Z light-blocking layers may include a top light-blocking layer 412, an intermediate light-blocking layer 413, and a bottom light-blocking layer 414, and the optical sensing pixel array may include a plurality of optical sensing pixels 415. C represents the maximum aperture of a single microlens. If the microlens is a square or other shaped microlens, C may be the maximum length of the microlens cross section in the periodic direction. P represents the period of the microlens. H represents the height of a single microlens, that is, the height from the vertex of the microlens to the top of the flat layer. _D1 , _D2 , and _D3 represent the maximum aperture of the small holes in the bottom light-blocking layer 414, the intermediate light-blocking layer 413, and the top light-blocking layer 412, respectively, that is, the size of the maximum aperture of the opening. _X1 , _X2 , and _X3 represent the offset of the center position of the opening in the bottom light-blocking layer 414, the intermediate light-blocking layer 413, and the top light-blocking layer 412 from the center position of the corresponding microlens on the plane where the microlens array is located. Z ₁ , Z ₂ , and Z ₃ respectively represent the distances between the bottom light blocking layer 414 , the middle light blocking layer 413 , and the top light blocking layer 412 and the bottom (eg, the lower surface) of the microlens array.

The microlenses in the microlens array may be circular microlenses, that is, FIG. 68 may be a side sectional view of the fingerprint detection device 40 shown in FIG. 69 along the E-E' direction. The microlenses in the microlens array may also be square microlenses. That is, FIG. 69 may be a side sectional view of the fingerprint detection device 40 shown in FIG. 70 along the F-F' direction. For example, the microlenses in the microlens array are circular microlenses, and the gaps between adjacent circular microlenses in the circular microlens matrix are large, resulting in a small proportion of their effective light-collecting area, which is generally 60%; the microlenses in the square microlens matrix can be obtained by cutting a sphere into a rectangular shape to obtain a square microlens, which can obtain a higher proportion of the light-collecting area (for example, more than 98%) compared to the circular microlens matrix. Of course, in order to achieve a high duty cycle, a single microlens may also be of other shapes.

Taking the structure shown in FIG68 as an example, the specific parameters of the fingerprint detection device are designed.

In some embodiments of the present application, the pinhole array of each of the Z light-blocking layers satisfies 0≤X _i /Z _d ≤3, so that the light signal returned from the finger above the display screen is converged by the microlens array and then transmitted to the optical sensing pixel array through the pinhole array set in the Z light-blocking layers, and the light signal is used to detect the fingerprint information of the finger. Z _d represents the vertical distance between the bottom light-blocking layer and the microlens array, _Xi represents the distance between the projections of the first center and the second center on the plane where the microlens array is located, the first center is the center of the microlens in the microlens array, and the second center is the center of the pinhole in the i-th light-blocking layer of the Z light-blocking layers for transmitting the light signal converged by the microlens. For example, Z _d represents the vertical distance between the lower surface of the bottom light-blocking layer and the lower surface of the microlens array. For another example, Z _d represents the vertical distance between the upper surface of the bottom light-blocking layer and the lower surface of the microlens array. For example, the pinhole array of each of the Z light-blocking layers satisfies 0≤X _i /Z _d ≤3/2. For another example, the small hole array of each of the Z light-blocking layers satisfies 1/2≤X _i /Z _d ≤3/2.

The i-th light-blocking layer may be the i-th light-blocking layer from top to bottom, or the i-th light-blocking layer from bottom to top.

By constraining the structural parameters of the small holes in the small hole array, it is possible to avoid aliasing of light signals sent back from different positions of the finger, that is, to improve the brightness of the fingerprint image while ensuring the contrast of the fingerprint image, increase the signal-to-noise ratio and resolution of the fingerprint image, and improve the fingerprint recognition effect and recognition accuracy.

It should be noted that the structural parameter _Xi / _Zd of the pinholes in the pinhole array is the distance between the first center and the second center, which can be divided into three parameters in a spatial rectangular coordinate system. For example, the center position of each microlens array in the microlens array can be taken as the origin, the direction of the rows of the microlens array can be taken as the X-axis, the direction of the columns of the microlens array can be taken as the Y-axis, and the direction perpendicular to the XY plane can be taken as the Z-axis. At this time, the pinhole parameter _Xi can be replaced with the position of the pinhole in the XY coordinate system, and the pinhole parameter _Zd can be replaced with the parameter of the pinhole in the pinhole array in the Z-axis direction. For another example, the spatial position of each pinhole in the pinhole array can also be determined with the center position of the microlens array as the origin.

It should also be noted that, with respect to the parameters of the pinholes in the pinhole array, since a microlens may transmit the converged light signal to the corresponding optical sensing pixel through multiple pinholes, a microlens may correspond to multiple parameters _Xi / _Zd . In addition, since multiple microlenses may transmit the converged light signal to the corresponding optical sensing pixel through a pinhole, similarly, a pinhole may correspond to multiple parameters _Xi / _Zd . In other words, the spatial structure of a pinhole can be designed using multiple parameters _Xi / _Zd .

In some embodiments of the present application, the maximum aperture of the small holes in the small hole array in the bottom light-blocking layer needs to be greater than a first preset value and less than a second preset value.

For example, the pinholes in the pinhole array in the bottom light-blocking layer satisfy 0um＜D _d ≤6um, where D _d represents the maximum aperture of the pinholes in the pinhole array in the bottom light-blocking layer. For example, the pinholes in the pinhole array in the bottom light-blocking layer satisfy 0.5um＜D _d ≤5um. For another example, the pinholes in the pinhole array in the bottom light-blocking layer satisfy 0.4um＜D _d ≤4um.

The fingerprint image obtained by pinhole imaging has a greater image contrast and a smaller brightness (i.e., the light entering the pinhole). Correspondingly, the greater the brightness, the smaller the image contrast. In this embodiment, by constraining the maximum aperture of the pinholes in the pinhole array, it is possible not only to ensure that each optical sensing pixel of the optical sensing pixel array can receive sufficient light signals, but also to ensure that the imaged image has sufficient brightness.

In some embodiments of the present application, each microlens in the microlens array may satisfy the formula 0＜H/C≤1, where H represents the maximum thickness of the microlens in the microlens array, and C represents the maximum aperture of the microlens in the microlens array. For example, each microlens in the microlens array satisfies 0＜H/C≤1/2. For another example, each microlens in the microlens array satisfies 0.2＜H/C≤0.4.

The maximum aperture of the microlens may be the maximum width of the cross section of the microlens with the largest area. For example, if the microlens is a hemispherical lens, the maximum aperture of the microlens may be the maximum width of the plane of the hemispherical lens.

In other words, each microlens in the microlens array is a hemispherical microlens, and the curvature of each microlens in the microlens array is less than or equal to 0.5.

When acquiring a fingerprint image through pinhole imaging, it is necessary to ensure that the spherical aberration of the microlens in the microlens array does not affect the imaging quality. In this embodiment, by constraining the ratio between the maximum thickness and the maximum aperture of the microlens, on the basis of a miniaturized fingerprint detection device, it is possible to ensure that the microlens focuses the converged light signal into the pinhole of the underlying light-blocking layer, thereby ensuring the imaging quality of the fingerprint image. In other words, by constraining the ratio of H and C, the spherical aberration of the microlens array is reduced on the basis of ensuring that the fingerprint detection device has a smaller thickness, thereby ensuring the fingerprint recognition effect.

In some embodiments of the present application, the distance between the bottom light-blocking layer and the microlens array satisfies 0um≤Z _d ≤100um. For example, the distance between the bottom light-blocking layer and the microlens array satisfies 2um≤Z _d ≤50um. For another example, the distance between the bottom light-blocking layer and the microlens array satisfies 3um≤Z _d ≤40um.

By constraining the parameters between the bottom light-blocking layer and the microlens array, the thickness of the fingerprint detection device can be effectively reduced. Of course, the maximum distance or minimum distance between each of the Z light-blocking layers and the microlens array can also be constrained, which all belong to the technical solutions protected by the embodiments of the present application.

In some embodiments of the present application, the microlens array satisfies 0um＜P≤100um. For example, the microlens array satisfies 2um≤P≤50um. For another example, the microlens array satisfies 1um≤P≤40um. Wherein, P represents the period of the microlenses in the microlens array.

In other words, the distance between the center positions of two adjacent microlenses in the microlens array satisfies 0um＜P≤100um, that is, P can also be used to represent the distance between the center positions of two adjacent microlenses in the microlens array.

By constraining the period of the microlens array, it is not only convenient to produce the microlens array separately, but also beneficial to spatially match the optical sensing pixel array, thereby obtaining an optical fingerprint image with a desired resolution.

In some embodiments of the present application, the pinholes in the pinhole array in each of the Z light-blocking layers and the microlenses in the microlens array satisfy 0＜D _i /P≤3, wherein _Di represents the aperture of the pinholes in the pinhole array in the i-th light-blocking layer in the Z light-blocking layers, and P represents the period of the microlenses in the microlens array. For example, the pinholes in the pinhole array in each of the Z light-blocking layers and the microlenses in the microlens array satisfy 0＜D _i /P≤2. For another example, the pinholes in the pinhole array in each of the Z light-blocking layers and the microlenses in the microlens array satisfy 1＜D _i /P≤4.

In other words, a small hole in the small hole array in the fingerprint detection device can correspond to a microlens or multiple microlenses. That is, one or more microlenses can transmit the light signal to the corresponding optical sensing pixel through a small hole in the small hole array.

For array-distributed microlens arrays and pinhole arrays, the design of optical path parameters can be effectively simplified by using the parameter _Di /P.

In some embodiments of the present application, the microlens array satisfies 0＜C/P≤1, wherein C represents the maximum aperture of the microlenses in the microlens array, and P represents the period of the microlenses in the microlens array.

By constraining the ratio between C and P, the duty cycle of the microlens array can be increased, thereby ensuring that the fingerprint detection device has a smaller volume.

In some embodiments of the present application, the Z light-blocking layers satisfy 0≤Z _i /Z _d ≤1, wherein _Zi represents the vertical distance between the i-th light-blocking layer in the Z light-blocking layers and the microlens array, and Z _d represents the vertical distance between the bottom light-blocking layer and the microlens array. For example, the Z light-blocking layers satisfy 0≤Z _i /Z _d ≤0.5.

In other words, by specifying the parameter _Zi / _Zd , the design parameters of the Z light-blocking layers can be simplified, so that the installation efficiency of the Z light-blocking layers can be improved during mass production.

The following are examples of specific values for the above parameters.

Table 1

parameter Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 P 16.88 10.45 22.50 8.75 7.86 18.14 12.50 13.63 11.50 C 15.53 9.61 22.50 8.75 7.86 16.68 9.09 12.54 10.58 H 4.37 1.71 6.55 2.76 3.17 3.63 2.06 1.96 2.47 D1 1.38 2.17 5.30 1.62 1.59 4.30 2.59 2.41 1.71 D2 13.51 4.01 7.47 3.12 4.09 6.50 5.81 7.97 12.22 D3 none 9.44 none none none 17.33 none 13.47 none X1 0.00 0.00 0.00 0.00 11.91 10.68 9.13 8.64 8.19 X2 0.00 0.00 0.00 0.00 9.93 6.85 3.10 3.40 2.79 X3 none 0.00 none none none 0.00 none 2.00 none Z1 18.13 19.90 27.34 11.79 12.78 25.43 21.45 23.74 22.20 Z2 1.79 16.25 15.44 8.41 7.74 20.90 13.30 15.24 14.99 Z3 none 0.75 none none none 1.72 none 10.86 none

As shown in Table 1, the fingerprint detection device can be provided with two light-blocking layers (i.e., light-blocking layers associated with Z1 and Z2), or can be provided with three light-blocking layers (i.e., light-blocking layers associated with Z1, Z2, and Z3). Of course, the number of light-blocking layers provided can also be one, or greater than three, and this application does not make any specific limitation on this.

Based on the values of the parameters in Table 1, Table 2 exemplarily shows the structural parameters of the fingerprint detection device designed by the ratio of two parameters.

Table 2

As shown in Table 2, the structure of the fingerprint detection device can also be designed using the ratio of the two parameters mentioned above. It should be noted that the embodiments of the present application are not limited to the above specific values, and those skilled in the art can determine the specific values of each parameter according to the actual optical path design requirements. For example, the above parameters can be accurate to three or four decimal places.

In some embodiments of the present application, the fingerprint detection device may include a plurality of fingerprint detection units distributed in an array or staggered arrangement, and the center position of a photosensitive area of each of a plurality of optical sensing pixels in each of the plurality of fingerprint detection units is offset relative to the center position of the same optical sensing pixel.

In other words, the center position of the photosensitive area of each of the plurality of optical sensing pixels does not coincide with the center position of the same optical sensing pixel. In other words, the photosensitive area of the fingerprint detection device is arranged in a periodic unit of fingerprint detection units, rather than in a periodic unit of optical sensing pixels.

By offsetting the center position of the photosensitive area of each of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel, the image distance of the one microlens can be increased when the vertical distance between the one microlens and the multiple optical sensing pixels is constant, thereby reducing the thickness of the fingerprint detection device.

In other words, for the fingerprint detection device, by receiving light signals at multiple tilt angles and shifting the center position of the photosensitive area of the optical sensing pixel, the thickness of the fingerprint detection device can be reduced as much as possible.

It should be understood that the optical sensing pixel in the present application may refer to an area on a substrate where a photosensitive device is provided, and the photosensitive area of the optical sensing pixel refers to an area where an inclined light signal can be guided to the optical sensing pixel through an opening in at least one light blocking layer. In other words, the photosensitive area may also refer to an area in the optical sensing pixel that can be illuminated by an opening in the light blocking layer in the fingerprint detection unit, and the sensing area is also called a light spot area.

In some embodiments of the present application, the distance between the center position of each of the multiple optical sensing pixels and the center position of the one microlens is smaller than the distance between the center position of the photosensitive area of the same optical sensing pixel and the center position of the one microlens.

In other words, the center position of the photosensitive area of each optical sensing pixel among the multiple optical sensing pixels is offset relative to the center position of the same optical sensing pixel, which can increase the distance between the center position of the photosensitive area of each optical sensing pixel among the multiple optical sensing pixels and the center position of the one microlens.

In this way, the image distance of the one microlens can be increased while keeping the vertical distance between the one microlens and the multiple optical sensing pixels unchanged.

In some embodiments of the present application, a light spot area is formed on the photosensitive area of each of the multiple optical sensing pixels through an opening set in the at least one light blocking layer, and the center position of the light spot area is offset by a first distance relative to the projection of the center position of the one microlens on the plane where the multiple optical sensing pixels are located. A line between the center position of the one microlens and the center position of the light spot area forms a first angle with a direction perpendicular to the display screen, and the first distance is inversely proportional to the cotangent of the first angle.

The first angle may be a refraction angle of light when it enters the fingerprint detection unit or the optical path medium of the fingerprint detection unit from the air, and the optical path medium may include the one microlens and a transparent medium between the one microlens and the plurality of optical sensing pixels.

In other words, the first angle may be an oblique incident angle of the fingerprint detection unit or an optical path medium of the fingerprint detection unit.

In other words, the first angle may be an angle between the fingerprint detection unit or the inclined light signal transmitted in the optical path medium of the fingerprint detection unit and a direction perpendicular to the display screen.

As an example, the light spot area is smaller than the photosensitive area of each of the plurality of optical sensing pixels, and the light spot area is arranged on a side of the photosensitive area close to or away from the one microlens. Of course, the light spot area can also be arranged at the center of the photosensitive area.

In some embodiments of the present application, a vertical distance between the one microlens and the plurality of optical sensing pixels is equal to a product of a cotangent of the first angle and the first distance.

In other words, the vertical distance can be determined by the formula h=x*cotθ, where h is the vertical distance, x is the first distance, and θ is the first angle. The vertical distance can also be called the optical path height of the fingerprint detection unit.

In this way, it can be ensured that the one microlens images the light signal returned by the finger onto the multiple optical sensing pixels to form a fingerprint image.

In other words, setting the vertical distance to the product of the cotangent of the first angle and the first distance can enable the one microlens to image the inclined light signals in multiple directions onto the offset photosensitive area.

Taking the light signal with an oblique incident angle of 26° in the air (i.e., the first angle) as an example, it is assumed that the parameters of the fingerprint detection unit in the fingerprint detection device are as follows:

The multiple optical sensing pixels are located below the one microlens, and the multiple optical sensing pixels are a 2x2 optical sensing pixel rectangular array. Each optical sensing pixel in the 2x2 optical sensing pixel rectangular array is a rectangular pixel with a side length of 7.5um. The center position of the photosensitive area of each optical sensing pixel in the 2x2 optical sensing pixel rectangular array is 5um away from the center position of the 2x2 optical sensing pixel rectangular array, and the oblique incident angle (i.e., the first angle) of the optical path medium of the fingerprint detection unit is approximately 19°.

At this time, if the period of the microlens in the fingerprint detection device is 15 um and the center position of the photosensitive area is offset, the thickness of the optical path of the fingerprint detection unit is about 20 um.

At the same time, if the period of the microlens in the fingerprint detection device is 7.5um (ie, the microlens and the optical sensing pixel correspond one to one), and the center position of the photosensitive area is not offset, the optical path of the fingerprint detection unit needs to be 40um, and the processing difficulty increases exponentially.

It can be seen that the fingerprint detection device of the present application has a thinner optical path thickness than the solution in which the photosensitive area is evenly distributed.

In a specific implementation, the angle (i.e., the first angle) and direction of the inclined light signals to be received by the multiple optical sensing pixels can be reasonably designed by adjusting at least one of the offset of the center position of the photosensitive area, the position of the light spot area in the photosensitive area, the position of the bottom light blocking layer of the at least one light blocking layer, the setting position of the opening in the at least one light blocking layer, the curvature radius of the microlens, and the optical path height of the fingerprint detection unit.

In some embodiments of the present application, the center position of the photosensitive area of each optical sensing pixel of the plurality of optical sensing pixels is offset in a direction away from or close to the center position of the plurality of optical sensing pixels relative to the center position of the same optical sensing pixel.

In other words, a person skilled in the art can determine the first distance based on the first angle and the vertical distance, and further determine the positional relationship between the one microlens and the multiple optical sensing pixels based on the first distance. For example, the multiple optical sensing pixels are located below the one microlens. For another example, the multiple optical sensing pixels are respectively located below multiple microlenses adjacent to the one microlens.

For example, the multiple optical sensing pixels are arranged below the one microlens, and the center position of the photosensitive area of each of the multiple optical sensing pixels is offset in a direction away from the center position of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel.

In other words, assuming that each of the multiple optical sensing pixels is a rectangular pixel, after a technician in this field determines the first distance based on the first angle and the vertical distance, if the first distance is less than the length of the hypotenuse of the rectangular pixel, it means that the one microlens can converge the received inclined light signal to the photosensitive areas of the multiple optical sensing pixels under the one microlens.

At this time, the offset distance of the center position of the photosensitive area of each of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel can be determined by the formula y=x-1/2L, wherein y represents the offset distance, and a positive number of y indicates that the center position of the photosensitive area of each of the multiple optical sensing pixels is offset in a direction away from the center position of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel. A negative number of y indicates that the center position of the photosensitive area of each of the multiple optical sensing pixels is offset in a direction close to the center position of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel.

Of course, the offset distance of the center position of the photosensitive area of each of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel can also be determined by the formula y=x-1/2L-z, wherein z represents the offset distance of the center position of the light spot area relative to the center position of the sensing area. z is a positive number indicating the offset distance of the center position of the light spot area relative to the center position of the sensing area in a direction away from the center positions of the multiple optical sensing pixels, and z is a negative number indicating the offset distance of the center position of the light spot area relative to the center position of the sensing area in a direction close to the center positions of the multiple optical sensing pixels.

For another example, the multiple optical sensing pixels are respectively located below a plurality of microlenses adjacent to the first microlens, and the center position of the photosensitive area of each of the multiple optical sensing pixels is offset relative to the center position of the same optical sensing pixel in a direction away from or close to the center position of the multiple optical sensing pixels.

In other words, assuming that each of the multiple optical sensing pixels is a rectangular pixel, after the technicians in this field determine the first distance based on the first angle and the vertical distance, if the first distance is greater than the length of the hypotenuse of the rectangular pixel, it means that the one microlens can converge the received inclined light signal to the photosensitive area of the optical sensing pixel under the multiple microlenses adjacent to the one microlens.

At this time, the offset distance of the center position of the photosensitive area of each of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel can be determined by the formula y=x-L, wherein y represents the offset distance, and a positive number of y indicates that the center position of the photosensitive area of each of the multiple optical sensing pixels is offset in a direction closer to the center position of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel. A negative number of y indicates that the center position of the photosensitive area of each of the multiple optical sensing pixels is offset in a direction away from the center position of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel.

Of course, the offset distance of the center position of the photosensitive area of each of the multiple optical sensing pixels relative to the center position of the same optical sensing pixel can also be determined by the formula y=x-L-z, wherein z represents the offset distance of the center position of the light spot area relative to the center position of the sensing area. z is a positive number indicating the offset distance of the center position of the light spot area relative to the center position of the sensing area in a direction close to the center positions of the multiple optical sensing pixels, and z is a negative number indicating the offset distance of the center position of the light spot area relative to the center position of the sensing area in a direction away from the center positions of the multiple optical sensing pixels.

For example, the center position of the photosensitive area of each optical sensing pixel among the multiple optical sensing pixels is offset along the diagonal line of the same optical sensing pixel, so that the center position of the photosensitive area of each optical sensing pixel among the multiple optical sensing pixels is located on the diagonal line of the same optical sensing pixel.

Taking the case where the plurality of optical sensing pixels are a 2×2 optical sensing pixel rectangular array as an example, the four photosensitive areas of the 2×2 optical sensing pixel rectangular array may be distributed at the four corners of the 2×2 optical sensing pixel rectangular array.

For another example, the center position of the photosensitive area of each optical sensing pixel among the multiple optical sensing pixels is offset along the side length of the same optical sensing pixel, so that a line connecting the center position of the photosensitive area of each optical sensing pixel among the multiple optical sensing pixels and the center position of the same optical sensing pixel is parallel to the side length of the same optical sensing pixel.

Taking the case where the plurality of optical sensing pixels are a 2×2 optical sensing pixel rectangular array as an example, the four photosensitive areas of the 2×2 optical sensing pixel rectangular array may be distributed on four sides of the 2×2 optical sensing pixel rectangular array.

In some embodiments of the present application, the center position of the photosensitive area of each of the plurality of optical sensing pixels is offset by a first distance relative to the center position of the same optical sensing pixel, and each of the plurality of optical sensing pixels is a rectangular pixel, and the first distance is less than or equal to the side length P of the rectangular pixel. For example, the first distance ranges from P/10 to P/2.

In some embodiments of the present application, the angle of the inclined light signal in each of the multiple directions relative to the display screen ranges from 10 degrees to 60 degrees. For example, the angles of the inclined light signals in the multiple directions relative to the display screen are the same.

In other words, the oblique incident angle in air may range from 10 degrees to 60 degrees.

In some embodiments of the present application, the at least one light-blocking layer is a plurality of light-blocking layers, and the bottom light-blocking layer among the plurality of light-blocking layers is provided with a plurality of openings corresponding to the plurality of optical sensing pixels, respectively, so that the one microlens converges the inclined light signals in the plurality of directions to the photosensitive areas of the plurality of optical sensing pixels, respectively, through the plurality of openings. The top light-blocking layer of the plurality of light-blocking layers is provided with at least one opening corresponding to the plurality of optical sensing pixels. For example, an opening may be provided in the top light-blocking layer for each of the plurality of optical sensing pixels, and for another example, an opening may be provided in the top light-blocking layer for at least two of the plurality of optical sensing pixels.

For example, the apertures of the openings in the plurality of light-blocking layers corresponding to the same optical sensing pixel decrease in sequence from top to bottom.

In other words, the aperture of the opening in the upper light-blocking layer is set larger than the aperture of the opening in the lower light-blocking layer, thereby enabling the multiple light-blocking layers to guide more (a certain angle range) light signals to the corresponding photosensitive pixels.

For another example, the metal wiring layer of the multiple optical sensing pixels is arranged at the rear focal plane position of the one microlens, and the metal wiring layer is respectively formed with multiple openings above the photosensitive areas of the multiple optical sensing pixels to form the bottom light blocking layer of the multiple light blocking layers.

In other words, an opening corresponding to the photosensitive area of each optical sensing pixel is formed on the metal wiring layer of the fingerprint sensor chip to form the bottom light blocking layer of the multiple light blocking layers. In other words, the metal wiring layer of the fingerprint sensor chip can be reused as the optical path layer between the microlens and the optical sensing pixel.

Taking the at least one light-blocking layer as 2-3 layers of aperture as an example, there are four optical sensing pixels (such as photodiode pixels) under one microlens, and the center of the photosensitive area (Active Area, AA) of each optical sensing pixel is offset relative to the center position of the same optical sensing pixel. Through the reasonable combination of apertures, the one microlens unit can simultaneously receive light signals in four oblique directions and converge them to the four optical sensing pixels respectively.

In some other embodiments of the present application, the at least one light-blocking layer is a light-blocking layer, and the one light-blocking layer is provided with a plurality of inclined holes corresponding to the plurality of optical sensing pixels, so that the one microlens can converge the inclined light signals in the plurality of directions to the photosensitive areas of the plurality of optical sensing pixels through the plurality of inclined holes.

For example, the thickness of the light blocking layer is greater than or equal to a preset thickness, so that the multiple inclined holes are respectively used to transmit inclined light signals in the multiple directions and crosstalk of the inclined light signals transmitted by the multiple inclined holes can be avoided.

It should be understood that in a specific implementation, those skilled in the art can determine the inclination angle of each of the plurality of inclined holes according to the optical path design requirements, and the plurality of inclined holes can be a plurality of inclined holes with different inclination angles, or can be inclined holes with partially or completely the same inclination angles. The directions of the plurality of inclined holes can be the directions of the light signals that the optical sensing pixels expect to receive after being converged by the microlenses.

In a specific implementation, the transmittance of each light-blocking layer in the at least one light-blocking layer to light in a specific band (such as visible light or a band above 610 nm) is less than a preset threshold value (for example, 20%) to prevent the corresponding light from passing through. The opening may be a cylindrical through hole, or a through hole of other shapes, such as a polygonal through hole. The aperture of the opening may be greater than a predetermined value, for example, the aperture of the opening is greater than 100 nm, so as to facilitate the transmission of the required light for imaging. The aperture of the opening should also be less than a predetermined value to ensure that the light-blocking layer can block unnecessary light. For another example, the aperture of the opening may be smaller than the diameter of the microlens.

As an example, the openings in the at least one light-blocking layer may also include a large-aperture opening equivalently synthesized by a plurality of small-aperture openings. For example, the plurality of small-aperture openings may be a plurality of openings corresponding to a plurality of optical sensing pixels. For example, a plurality of small-aperture openings in the top light-blocking layer of the at least one light-blocking layer for transmitting light signals converged by the same microlens may be combined into a large-aperture opening.

For example, each of the at least one light-blocking layer may be a metal layer, and accordingly, the openings provided in the light-blocking layer may be through holes formed in the metal layer. The light-blocking layer in the at least one light-blocking layer may also be a black polymer light-absorbing material. For example, for a light signal greater than a preset angle, the at least one light-blocking layer has a visible light band transmittance of less than 2%.

It should be understood that the parameters of the opening should be set so that the light signal required for imaging is transmitted to the optical sensing pixel as much as possible, while the unnecessary light is blocked as much as possible. For example, the parameters of the opening can be set so that the light signal incident at a specific angle (such as 35 degrees) is transmitted to the corresponding optical sensing pixel as much as possible, while other light signals are blocked as much as possible.

It should be understood that the above drawings are merely examples of the present application and should not be construed as limitations of the present application.

As an example, in some embodiments of the present application, the fingerprint detection device may further include a transparent medium layer, wherein the transparent medium layer is used to connect the one microlens, the at least one light blocking layer, and the plurality of optical sensing pixels.

For example, the transparent medium layer can transmit the optical signal of the target band (i.e., the optical signal of the band required for fingerprint detection). For example, the transparent medium layer can be made of oxide or nitride. Optionally, the transparent medium layer can include multiple layers to respectively realize the functions of protection, transition and buffer. For example, a transition layer can be set between the inorganic layer and the organic layer to achieve a close connection; a protective layer can be set on the easily oxidized layer to achieve protection.

As another example, in some embodiments of the present application, the fingerprint detection device further includes a filter layer, wherein the filter layer is arranged in the optical path between the microlens array and the optical sensing pixel array or arranged above the microlens array, and the filter layer is used to filter out light signals in non-target bands to transmit light signals in target bands.

For example, the filter layer may be a polarizer, a color filter, an infrared filter, etc., to achieve functions such as selecting polarization and selecting a specific spectrum.

For another example, the transmittance of the filter layer to the light in the target band may be greater than or equal to a preset threshold, and the cutoff rate to the light in the non-target band may be greater than or equal to the preset threshold. For example, the preset threshold may be 80%. Optionally, the filter layer may be an independently formed filter layer. For example, the filter layer may be a filter layer formed using blue crystal or blue glass as a carrier. Optionally, the filter layer may be a coating formed on the surface of any layer in the optical path. For example, a coating may be formed on the surface of an optical sensing pixel, the surface of any layer in the transparent medium layer, or the surface of a microlens, thereby forming a filter layer.

For another example, the fingerprint detection device may also include an image sensor driving unit, a microprogrammed control unit (MCU) and other devices.

The preferred embodiments of the present application are described in detail above in conjunction with the accompanying drawings; however, the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all fall within the protection scope of the present application.

For example, the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this application will not further explain various possible combinations.

For another example, the various implementation modes of the present application may be arbitrarily combined, and as long as they do not violate the concept of the present application, they should also be regarded as the contents disclosed in the present application.

It should be understood that in the various method embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

An embodiment of the present application also provides an electronic device, which may include a display screen and a fingerprint detection device of the above-mentioned embodiment of the present application, wherein the fingerprint detection device is arranged under the display screen to realize under-screen optical fingerprint detection.

The electronic device may be any electronic device having a display screen. For example, the electronic device may be the electronic device 10 shown in FIG. 1 to FIG. 4 .

The display screen may be the display screen described above, such as an OLED display screen or other display screens. For the relevant description of the display screen, please refer to the description of the display screen in the above description. For the sake of brevity, it will not be repeated here.

In some embodiments of the present application, a foam layer may be provided below the display screen, and the foam layer may be provided with at least one opening above the fingerprint detection device, and the at least one opening is used to transmit the light signal reflected by the finger to the fingerprint detection device.

For example, there is a layer of black foam under the display screen, and the black foam may be provided with an opening above the fingerprint detection device. When a finger is placed above the lit display screen, the finger will reflect the light emitted by the display screen, and the reflected light reflected by the finger will penetrate the display screen and be transmitted to the fingerprint detection device through the at least one opening. The fingerprint is a diffuse reflector, and its reflected light exists in all directions.

At this time, a specific optical path in the fingerprint detection device can be used to enable the optical sensing pixel array in the fingerprint detection device to receive inclined light signals in multiple directions. The processing unit in the fingerprint detection device or the processing unit connected to the fingerprint detection device can obtain a reconstructed fingerprint image through an algorithm, and then perform fingerprint recognition.

In some embodiments of the present application, there may or may not be a gap between the fingerprint detection device and the display screen.

For example, there may be a gap of 0-1000 um between the fingerprint detection device and the display screen.

In some embodiments of the present application, the fingerprint detection device can output the collected image to an MCU, an FPGA, a DSP, a computer-specific processor, or a dedicated processor of an electronic device to perform fingerprint recognition.

It should be understood that the specific examples in the embodiments of the present application are only intended to help those skilled in the art better understand the embodiments of the present application, rather than to limit the scope of the embodiments of the present application.

It should be understood that the terms used in the embodiments of the present application and the appended claims are only for the purpose of describing specific embodiments, and are not intended to limit the embodiments of the present application. For example, the singular forms "a", "above", and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

Those of ordinary skill in the art will appreciate that the units of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

In the several embodiments provided in the present application, it should be understood that the disclosed systems and devices can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, or it can be an electrical, mechanical or other form of connection.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiments of the present application.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims (23)

1. A fingerprint detection device, characterized in that it is suitable for use under a display screen to realize under-screen optical fingerprint detection, the fingerprint detection device comprises a plurality of fingerprint detection units distributed in an array or staggered, and each of the plurality of fingerprint detection units comprises: A plurality of optical sensing pixels, wherein the optical sensing pixels are photoelectric sensors; at least one microlens disposed above the plurality of optical sensing pixels; At least one light-blocking layer is disposed between the at least one microlens and the plurality of optical sensing pixels, and each of the at least one light-blocking layer is provided with openings corresponding to the plurality of optical sensing pixels; Among them, the inclined light signals in 2M directions reflected from the finger above the display screen are converged by the at least one microlens and then transmitted to the multiple optical sensing pixels respectively through the openings set in the at least one light blocking layer, and the inclined light signals are used to detect the fingerprint information of the finger. M is a positive integer, and the 2M directions include a first direction and a second direction, and the projection of the first direction on the display screen is perpendicular to the projection of the second direction on the display screen. 2. The fingerprint detection device according to claim 1 is characterized in that a projection of the first direction or the second direction on the display screen is perpendicular to a polarization direction of the display screen. 3. The fingerprint detection device according to claim 1 is characterized in that the multiple optical sensing pixels form an optical sensing pixel rectangular array, and the projection of the first direction or the second direction on the optical sensing pixel rectangular array is parallel to the diagonal direction of the optical sensing pixel rectangular array. 4. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the at least one microlens is one microlens, the multiple optical sensing pixels are the first column of optical sensing pixels in a 2x2 optical sensing pixel matrix array, the one microlens is located above the center position of the 2x2 optical sensing pixel matrix array, and the second column of optical sensing pixels in the 2x2 optical sensing pixel matrix array is multiplexed as optical sensing pixels in the first column of optical sensing pixels in other fingerprint detection units. 5. The fingerprint detection device according to claim 4 is characterized in that two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 2x2 optical sensing pixel matrix array are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 2x2 optical sensing pixel matrix array. 6. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the at least one microlens is one microlens, the multiple optical sensing pixels are the first row and first column optical sensing pixels and the first column optical sensing pixels in the fourth row in the first column of optical sensing pixels in a 4x2 optical sensing pixel matrix array, the one microlens is located above the center position of the side length of the second column of optical sensing pixels in the 4x2 optical sensing pixel matrix array away from the first column of optical sensing pixels, and the optical sensing pixels in the 4x2 optical sensing pixel matrix array except the first row and first column optical sensing pixels and the first column optical sensing pixels in the fourth row are multiplexed as optical sensing pixels in other fingerprint detection units. 7. The fingerprint detection device according to claim 6 is characterized in that two fingerprint detection units in the fingerprint detection device that are adjacent in the row direction of the 4x2 optical sensing pixel matrix array are offset by one optical sensing pixel in the arrangement direction of the first column of optical sensing pixels in the 4x2 optical sensing pixel matrix array. 8. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the multiple optical sensing pixels are a 4x4 optical sensing pixel rectangular array, and the 4x4 optical sensing pixel rectangular array includes 4 2x2 optical sensing pixel rectangular arrays distributed in an array, wherein the 2x2 optical sensing pixel rectangular array in the first column and the first row and the 2x2 optical sensing pixel rectangular array in the second row and the second column of the 4x4 optical sensing pixel rectangular array are used to receive inclined light signals in one direction, and the 2x2 optical sensing pixel rectangular array in the first column and the second row and the 2x2 optical sensing pixel rectangular array in the first row and the second column of the 4x4 optical sensing pixel rectangular array are used to receive inclined light signals in another direction. 9. The fingerprint detection device according to claim 8, characterized in that the at least one microlens comprises a 3x2 microlens rectangular array and two 2x2 microlens rectangular arrays, the 3x2 microlens rectangular array is located above the first to third columns of optical sensing pixels in the 4x4 optical sensing pixel rectangular array, the two 2x2 microlens rectangular arrays are respectively located above the first and fourth rows of optical sensing pixels in the fourth column of optical sensing pixels in the 4x4 optical sensing pixel rectangular array, and the four microlenses in each of the two 2x2 microlens rectangular arrays are respectively located above the four corners of the corresponding optical sensing pixels, so that the first column and first row 2x2 optical sensing pixel rectangular array and the second row and second column 2x2 optical sensing pixel rectangular array in the 4x4 optical sensing pixel rectangular array receive an inclined light signal in one diagonal direction of the 4x4 optical sensing pixel rectangular array, and the first column and second row 2x2 optical sensing pixel rectangular array and the first row and second column 2x2 optical sensing pixel rectangular array in the 4x4 optical sensing pixel rectangular array receive an inclined light signal in another diagonal direction. 10. The fingerprint detection device according to claim 9, characterized in that the microlenses in the two 2x2 microlens rectangular arrays located above the side length of the 4x4 optical sensing pixel rectangular array are reused as microlenses in other fingerprint detection units. 11. The fingerprint detection device according to claim 8 is characterized in that each optical sensing pixel in the 4x4 optical sensing pixel rectangular array is used to receive the light signal converged by the microlens above the adjacent optical sensing pixel, so that the 2x2 optical sensing pixel rectangular array in the first column and the first row and the 2x2 optical sensing pixel rectangular array in the second row and the second column of the 4x4 optical sensing pixel rectangular array receive the inclined light signal in the direction of one side length of the 4x4 optical sensing pixel rectangular array, and the 2x2 optical sensing pixel rectangular array in the first column and the second row and the second column of the 4x4 optical sensing pixel rectangular array receive the inclined light signal in the direction of another side length adjacent to the one side length. 12. The fingerprint detection device according to claim 11, characterized in that the microlens located above the outer area of the 4x4 optical sensing pixel rectangular array in the at least one microlens is reused as a microlens in other fingerprint detection units. 13. The fingerprint detection device according to any one of claims 1 to 3 is characterized in that the multiple optical sensing pixels are multiple rows of optical sensing pixels, at least one row of first optical sensing pixels in the multiple rows of optical sensing pixels is used to receive inclined light signals in one direction, and at least one row of second optical sensing pixels in the multiple rows of optical sensing pixels is used to receive inclined light signals in another direction. 14. The fingerprint detection device according to claim 13 is characterized in that each optical sensing pixel in the multiple rows of optical sensing pixels is used to receive the light signal converged by the microlens above the adjacent optical sensing pixel, so that the at least one row of first optical sensing pixels receives the inclined light signal along the arrangement direction of the optical sensing pixels, and the at least one row of second optical sensing pixels receives the inclined light signal along the direction perpendicular to the arrangement direction of the optical sensing pixels. 15. The fingerprint detection device according to claim 13 is characterized in that the at least one microlens is a 3x1 microlens rectangular array, the multiple optical sensing pixels are the first column of optical sensing pixels in a 4x2 optical sensing pixel rectangular array, the 3x1 microlens rectangular array is located above the 4x2 optical sensing pixel rectangular array, and the second column of optical sensing pixels in the 4x2 optical sensing pixel rectangular array is multiplexed as optical sensing pixels in other fingerprint detection units. 16. The fingerprint detection device according to any one of claims 1 to 3 is characterized in that the at least one light-blocking layer is a multi-layer light-blocking layer, and the bottom light-blocking layer in the multi-layer light-blocking layer is provided with a plurality of openings corresponding to the plurality of optical sensing pixels, respectively, so that the at least one microlens can converge the inclined light signals in the 2M directions to the plurality of optical sensing pixels through the plurality of openings. 17. The fingerprint detection device according to claim 16, characterized in that the apertures of the openings corresponding to the same optical sensing pixel in the multi-layer light-blocking layer decrease in diameter from top to bottom. 18. The fingerprint detection device according to claim 16, characterized in that a top light-blocking layer of the multi-layer light-blocking layer is provided with at least one opening corresponding to the plurality of optical sensing pixels. 19. The fingerprint detection device according to any one of claims 1 to 3 is characterized in that the at least one light-blocking layer is a light-blocking layer, and the light-blocking layer is provided with a plurality of inclined holes corresponding to the plurality of optical sensing pixels, so that the at least one microlens converges the inclined light signals in the 2M directions to the plurality of optical sensing pixels respectively through the plurality of openings. 20. The fingerprint detection device according to claim 19, characterized in that the thickness of the light-blocking layer is greater than or equal to a preset thickness, so that the multiple inclined holes are respectively used to transmit the inclined light signals in the 2M directions. 21. The fingerprint detection device according to any one of claims 1 to 3, characterized in that the fingerprint detection device also includes a transparent medium layer, and the transparent medium layer is used to connect the at least one microlens, the at least one light blocking layer and the multiple optical sensing pixels. 22. The fingerprint detection device according to any one of claims 1 to 3 is characterized in that the fingerprint detection device also includes a filter layer, which is arranged in the light path between the at least one microlens and the multiple optical sensing pixels or above the microlens, and is used to filter out light signals in non-target bands to pass light signals in target bands. 23. An electronic device, comprising: Display screen; and According to any one of claims 1 to 22, the fingerprint detection device is arranged below the display screen to realize under-screen optical fingerprint detection.