CN111108511B - Fingerprint detection device and electronic equipment - Google Patents

Abstract

The embodiment of the application relates to a fingerprint detection device and an electronic device, wherein the fingerprint detection device is applicable to the lower part of a display screen comprising a fingerprint detection area, and comprises: the fingerprint detection units are determined according to the relevant size parameters of each fingerprint detection unit or fingerprint detection area; each fingerprint detection unit comprises from top to bottom: a microlens array; at least one light blocking layer to form a plurality of inclined light guide channels corresponding to each microlens; and each optical sensing pixel is used for receiving optical signals converged by the micro lens and transmitted through the corresponding light guide channel so as to detect fingerprint information of the finger. The fingerprint detection device and the electronic equipment provided by the embodiment of the application can realize the effective identification of the field of view of the same fingerprint by using a smaller chip area, and reduce the cost.

Description

Fingerprint detection device and electronic equipment

This application requires a PCT patent application submitted to the China Patent Office on July 12, 2019, with the application number PCT/CN2019/095880 and the application name "Fingerprint Detection Device and Electronic Equipment", and submitted to the China Patent Office on August 2, 2019 , the PCT patent application with the application number PCT/CN2019/099135 and the application name "Fingerprint Detection Device and Electronic Equipment", and submitted to the China Patent Office on August 23, 2019, the application number is PCT/CN2019/102366, and the application name is The priority of the PCT patent application for "Fingerprint Detection Apparatus, Method and Electronic Device", the entire content of which is incorporated by reference in this application.

technical field

The present application relates to the field of biometric identification, in particular to a fingerprint detection device and electronic equipment.

Background technique

With the rapid development of the mobile phone industry, people pay more and more attention to biometric technology, and the practical application of more convenient and low-cost off-screen fingerprint recognition technology has become a public demand. Under-screen optical fingerprint recognition technology is to install an optical fingerprint module under the display screen, and realize fingerprint recognition by collecting optical fingerprint images. With the development of terminal products, the requirements for fingerprint identification performance, size and cost are getting higher and higher.

For example, the problem of dry fingers may appear in some scenarios. The contact area between the dry finger and the display is very small, and the recognition response area is very small, resulting in discontinuous collected fingerprints and easy loss of feature points, which affects the performance of fingerprint recognition. In addition, while solving the above-mentioned problem of how to improve the performance of fingerprint recognition, it is also necessary to consider the cost and size of the fingerprint recognition device when it is applied to the special scene under the screen.

Contents of the invention

The present application provides a fingerprint detection device and electronic equipment, which can realize the same effective fingerprint identification field of view with a smaller chip area, thereby reducing the chip area and cost.

In the first aspect, a fingerprint detection device is provided, the fingerprint detection device is suitable for use under the display screen to realize optical fingerprint detection under the screen, the display screen includes a fingerprint detection area, and the fingerprint detection area is used for finger touch to perform Fingerprint detection, the fingerprint detection device includes: a plurality of fingerprint detection units, the size of each fingerprint detection unit in the plurality of fingerprint detection units and the distance between two adjacent fingerprint detection units are set according to size parameters, The size parameters include at least one of the following parameters: the field of view of each fingerprint detection unit, the area of the fingerprint detection area, the thickness of the display screen, and the optical surface of each fingerprint detection unit The distance to the lower surface of the display.

Wherein, each fingerprint detection unit includes: a microlens array, configured to be arranged below the display screen, and includes a plurality of microlenses; at least one light blocking layer, arranged under the microlens array, and A plurality of light guide channels corresponding to each micro lens in the plurality of micro lenses are formed, and each light guide channel in the plurality of light guide channels corresponding to each micro lens is connected to the light of each micro lens The angle between the axes is less than 90°; the optical sensing pixel array is arranged under the at least one light blocking layer, and includes a plurality of optical sensing pixels, and each of the corresponding microlenses in the plurality of light guide channels An optical sensing pixel is arranged below each light guiding channel, and the optical sensing pixel is used to receive the light signal converged by the microlens and transmitted through the corresponding light guiding channel, and the light signal is used to detect the fingerprint information of the finger .

Therefore, the fingerprint detection device including a plurality of fingerprint detection units in the embodiment of the present application can solve the following problems: 1. The problem that the recognition effect of the vertical light signal on the dry finger is too poor; 2. The single-object telecentric microlens array solution 3. The thickness of the fingerprint detection device is too large; 4. The tolerance of the fingerprint detection device is too poor; 5. The size of the fingerprint detection device is too large; 6. The cost of the fingerprint detection device Too high a problem.

With reference to the first aspect, in an implementation manner of the first aspect, the sizes of the multiple fingerprint detection units are the same.

In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the multiple fingerprint detection units located in the same row among the multiple fingerprint detection units are separated by the same distance; and/or, the Among the multiple fingerprint detection units, the distances between the multiple fingerprint detection units located in the same row are equal.

With reference to the first aspect and the foregoing implementation manners thereof, in another implementation manner of the first aspect, the number of the plurality of fingerprint detection units is two.

With reference to the first aspect and the above-mentioned implementation manners thereof, in another implementation manner of the first aspect, two fingerprint detection units are arranged side by side.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is In the case where the edge of each fingerprint detection unit expands at least the first value X, and the length of the fingerprint detection area is greater than or equal to the second value Y, and the width of the fingerprint detection area is greater than or equal to the third value Z, the The length of each fingerprint detection unit is greater than or equal to Y-2X, the width of each fingerprint detection unit is greater than or equal to 0.5Z-2X, and the horizontal distance between the two fingerprint detection units is less than or equal to 2X.

For example, the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least 0.3 mm from the edge of each fingerprint detection unit, and the area of the fingerprint detection area In the case of greater than or equal to 6mm*6mm, the length of each fingerprint detection unit is greater than or equal to 5.4mm, the width of each fingerprint detection unit is greater than or equal to 2.4mm, and the distance between the two fingerprint detection units The horizontal distance is less than or equal to 0.6mm.

In combination with the first aspect and the above implementation manners, in another implementation manner of the first aspect, the length of each fingerprint detection unit is 6 mm, the width of each fingerprint detection unit is 2.3 mm, and the two The horizontal distance between each fingerprint detection unit is 1mm.

In combination with the first aspect and the above implementation manners, in another implementation manner of the first aspect, the length of each fingerprint detection unit is 6.5 mm, the width of each fingerprint detection unit is 2.6 mm, and the The horizontal distance between two fingerprint detection units is 1mm.

With reference to the first aspect and the foregoing implementation manners thereof, in another implementation manner of the first aspect, the number of the plurality of fingerprint detection units is four.

With reference to the first aspect and the foregoing implementation manners thereof, in another implementation manner of the first aspect, the four fingerprint detection units are arranged in a 2*2 matrix.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is In the case where the edge of each fingerprint detection unit expands at least the first value X, and the length of the fingerprint detection area is greater than or equal to the second value Y, and the width of the fingerprint detection area is greater than or equal to the third value Z, the The length of each fingerprint detection unit is greater than or equal to 0.5Y-2X, the width of each fingerprint detection unit is greater than or equal to 0.5Z-2X, and the horizontal distance between two adjacent fingerprint detection units in the horizontal direction is less than Or it is equal to 2X, and the vertical distance between two adjacent fingerprint detection units in the vertical direction is less than or equal to 2X.

For example, the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least 0.3 mm from the edge of each fingerprint detection unit, and the area of the fingerprint detection area In the case of greater than or equal to 6mm*6mm, the length of each fingerprint detection unit is greater than or equal to 2.4mm, the width of each fingerprint detection unit is greater than or equal to 2.4mm, and two adjacent fingerprint detection units in the horizontal direction The horizontal distance between the units is less than or equal to 0.6 mm, and the vertical distance between two adjacent fingerprint detection units in the vertical direction is less than or equal to 0.6 mm.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the length of each fingerprint detection unit is 2.3 mm, the width of each fingerprint detection unit is 2.3 mm, and the horizontal direction The horizontal distance between two adjacent fingerprint detection units is 1.2mm, and the vertical distance between two vertically adjacent fingerprint detection units is 1.2mm.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the length of each fingerprint detection unit is 2.6mm, the width of each fingerprint detection unit is 2.6mm, and the horizontal direction The horizontal distance between two adjacent fingerprint detection units is 1mm, and the vertical distance between two vertically adjacent fingerprint detection units is 1mm.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the bottoms of the plurality of light guide channels corresponding to each microlens respectively extend below the adjacent plurality of microlenses.

With reference to the first aspect and the foregoing implementation manners thereof, in another implementation manner of the first aspect, the bottoms of the plurality of light guide channels corresponding to each microlens are located below the same microlens.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the plurality of light guide channels corresponding to each microlens are center-symmetrically distributed along the optical axis direction of the same microlens.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, each of the plurality of light guide channels corresponding to each microlens and the first plane form a preset clip angle, so that the plurality of optical sensing pixels arranged under each microlens are respectively used to receive optical signals converged by one or more microlenses and transmitted through corresponding light guide channels, wherein the first plane is a plane parallel to the display screen.

With reference to the first aspect and the above-mentioned implementation manners thereof, in another implementation manner of the first aspect, the range of the preset included angle is 15 degrees to 60 degrees.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the projections of the plurality of light guide channels corresponding to each microlens on the first plane are relative to the optical axis of the same microlens Symmetrically distributed in the projection center of the first plane.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the optical sensing pixel array includes multiple groups of optical sensing pixels, and the same group of optical sensing pixels in the multiple groups of optical sensing pixels receives The directions of the light guide channels through which the light signals pass are the same, and the multiple groups of optical sensing pixels are used to receive light signals from multiple directions to obtain multiple images, and the multiple images are used to detect fingerprint information of the finger.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, a group of optical sensing pixels in the plurality of groups of optical sensing pixels is used to receive an optical signal in one direction of the plurality of directions An image among the plurality of images is obtained.

With reference to the first aspect and the above-mentioned implementation manners thereof, in another implementation manner of the first aspect, the number of pixels in each group of pixels in the plurality of groups of pixels is equal, and the arrangement manner is the same.

In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, one optical sensing pixel in a group of optical sensing pixels in the multiple groups of optical sensing pixels corresponds to a pixel point in an image .

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, a plurality of continuous optical sensing pixels in a group of optical sensing pixels in the multiple groups of optical sensing pixels correspond to the a pixel.

With reference to the first aspect and the foregoing implementation manners thereof, in another implementation manner of the first aspect, the distribution of the plurality of optical sensing pixels under each microlens is polygonal.

With reference to the first aspect and the foregoing implementation manners thereof, in another implementation manner of the first aspect, the polygon is a rectangle or a rhombus.

In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the at least one light-shielding layer is a plurality of light-shielding layers, and each of the microlenses corresponding to each light-shielding layer is provided in different light-shielding layers At least one opening of the microlens to form a plurality of light guide channels corresponding to each microlens.

With reference to the first aspect and the above implementation manners, in another implementation manner of the first aspect, the number of openings corresponding to the same microlens in different light blocking layers increases sequentially from top to bottom.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the apertures of the openings in different light-blocking layers corresponding to the same microlens decrease sequentially from top to bottom.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the bottom light-shielding layer among the plurality of light-shielding layers is provided with a plurality of openings corresponding to each microlens The plurality of light guiding channels corresponding to each microlens respectively pass through the plurality of openings corresponding to the same microlens in the bottom light blocking layer.

With reference to the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the non-bottom light-shielding layer in the plurality of light-shielding layers is located between two adjacent microlenses in the plurality of microlenses. The middle position of the back focus of the lens is provided with an opening, and the two light guide channels corresponding to the two adjacent microlenses pass through the corresponding two adjacent microlenses in the non-bottom light blocking layer. openings, so that the bottoms of the plurality of light guide channels corresponding to each microlens respectively extend below the adjacent plurality of microlenses.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the top light-shielding layer among the plurality of light-shielding layers is provided with an opening on the optical axis of each microlens , the plurality of light guiding channels corresponding to each microlens pass through the openings corresponding to the same microlens in the top light blocking layer.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the at least one light-blocking layer only includes one light-shielding layer, and the plurality of light-guiding channels are the one light-shielding layer Multiple inclined via holes corresponding to the same microlens in .

With reference to the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the thickness of the one light-blocking layer is greater than a preset threshold, so that the plurality of optical sensors disposed below each microlens The pixels are respectively used to receive light signals converged by one or more microlenses and transmitted through corresponding light guide channels.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, each fingerprint detection unit further includes: a transparent medium layer disposed at least one of the following positions:

Between the microlens array 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.

With reference to the first aspect and its above implementation manners, in another implementation manner of the first aspect, the at least one light blocking layer and the microlens array are integrated, or the at least one light blocking layer and the The integrated setup of the optical sensing pixel array.

In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, each microlens satisfies at least one of the following conditions: the light-gathering surface of the microlens is perpendicular to its optical axis The projection on the plane of the microlens is rectangular or circular; the light-gathering surface of the microlens is aspheric; the curvature of the light-gathering surface of the microlens is the same in all directions; the microlens includes at least one lens; and the The focal length range of the microlens is 10um-2mm.

In combination with the first aspect and its above-mentioned implementation manners, in another implementation manner of the first aspect, the microlens array satisfies at least one of the following conditions: the microlens array is arranged in a polygonal shape, and the microlens array The range of duty cycle is 100%-50%.

In combination with the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, the period of the microlens array is not equal to the period of the optical sensing pixel array, and the period of the microlens array is A rational multiple of the period of the optical sensing pixel array.

With reference to the first aspect and the above implementation manners, in another implementation manner of the first aspect, the distance between the fingerprint detection device and the display screen is 20um-3000um.

With reference to the first aspect and the above-mentioned implementation manners, in another implementation manner of the first aspect, each fingerprint detection unit further includes: a filter layer disposed at least one of the following positions: the microlens Above the array, and between the microlens array and the optical sensing pixel array.

In a second aspect, an electronic device is provided, including: a display screen; and a fingerprint detection device according to the first aspect or any possible implementation manner of the first aspect.

With reference to the second aspect, in an implementation manner of the second aspect, the display screen includes a fingerprint detection area, and the fingerprint detection area is used to provide a touch interface for a finger.

Description of drawings

FIG. 1 is a schematic front view of an electronic device according to an embodiment of the present application.

FIG. 2 is a schematic cross-sectional view of the electronic device in FIG. 1 according to an embodiment of the present application.

Fig. 3 is a front view of a fingerprint detection unit in the fingerprint detection device of the embodiment of the present application.

Fig. 4 is a front view of another fingerprint detection unit in the fingerprint detection device according to the embodiment of the present application.

FIG. 5 is a schematic top view of any microlens and its corresponding optical sensing pixel in the fingerprint detection unit according to the embodiment of the present application.

FIG. 6 is another schematic top view of any microlens and its corresponding optical sensing pixel in the fingerprint detection unit according to the embodiment of the present application.

Fig. 7 is a front view of another fingerprint detection unit in the fingerprint detection device according to the embodiment of the present application.

Fig. 8 is a front view of another fingerprint detection unit in the fingerprint detection device according to the embodiment of the present application.

FIG. 9 is a schematic view of the field of view of the fingerprint detection device with a single fingerprint detection unit according to the embodiment of the present application.

FIG. 10 is a schematic diagram of a calculation method of a field of view of a fingerprint detection device with a single fingerprint detection unit according to an embodiment of the present application.

FIG. 11 is a schematic diagram of the field of view of a fingerprint detection device with multiple fingerprint detection units according to an embodiment of the present application.

Fig. 12 is a schematic front view of the arrangement of two fingerprint detection units according to the embodiment of the present application.

Fig. 13 is a schematic front view of the arrangement of four fingerprint detection units according to the embodiment of the present application.

Fig. 14 is a schematic side view of the arrangement of four fingerprint detection units according to the embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

The technical solutions of the embodiments of the present application can be applied to various electronic devices. Examples include portable or mobile computing devices such as smartphones, laptops, tablets, gaming devices, and other electronic devices such as electronic databases, automobiles, and bank automated teller machines (ATMs). However, this embodiment of the present application is not limited thereto.

The technical solutions of the embodiments of the present application can be used in biometric identification technology. Among them, biometric identification technologies include but are not limited to fingerprint identification, palmprint identification, iris identification, face identification and living body identification and other identification technologies. For ease of description, the fingerprint recognition technology is taken as an example below for description.

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

The fingerprint identification technology under the screen refers to installing the fingerprint identification module under the display screen, so as to realize the fingerprint identification operation in the display area of the display screen, and does not 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 assembly of the electronic device to perform fingerprint sensing and other sensing operations. The returned light carries information of an object (such as a finger) that is in contact with or close to the top surface of the display component. The fingerprint recognition module located under the display component collects and detects the returned light to realize off-screen fingerprint recognition. Among them, the design of the fingerprint identification module can be to realize the desired optical imaging by properly configuring the optical elements for collecting and detecting the returned light, so as to detect the fingerprint information of the finger.

Correspondingly, the in-display fingerprint recognition technology refers to the installation of the fingerprint recognition module or part of the fingerprint recognition module inside the display screen, so as to realize the fingerprint recognition operation in the display area of the display screen, without the need of electronic devices. The fingerprint collection area is set on the front of the device except the display area.

FIG. 1 to FIG. 2 show schematic diagrams of electronic devices to which the embodiments of the present application can be applied. 1 is a front view of the electronic device 10 , and FIG. 2 is a schematic cross-sectional view of the electronic device 10 shown in FIG. 1 .

As shown in FIGS. 1 and 2 , the electronic device 10 may include a display screen 120 and an optical fingerprint identification module 130 .

The display screen 120 may be a self-luminous display screen, which uses a self-luminous display unit as a display pixel. For example, the display screen 120 may be an organic light-emitting diode (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 may also be a liquid crystal display (Liquid Crystal Display, LCD) or other passive light-emitting display screens, which is not limited in this embodiment of the present application. Furthermore, the display screen 120 can also be specifically a touch screen display, which can not only display images, but also detect touch or press operations of the user, 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 specifically be a touch panel (Touch Panel, TP), which may be disposed on the surface of the display screen 120, or may be partially or entirely integrated into the The inside of the display screen 120 forms a touch 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 corresponding to the optical fingerprint module 130 (also referred to as a fingerprint collection area, a fingerprint recognition area, etc.).

Wherein, the optical fingerprint module 130 is arranged in a local area below the display screen 120 .

As shown in 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 can also be arranged in other positions, such as the side of the display screen 120 or the edge non-transparent area of the electronic device 10, and the The optical signal of at least part of the display area of the screen 120 is guided to the optical fingerprint module 130 , 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 realize fingerprint input. Since the fingerprint detection can be realized in the screen, the electronic device 10 adopting the above-mentioned structure does not need to reserve a special space on its front to set a fingerprint button (such as a Home button), so that a full-screen solution can be adopted, that is, the display area of the display screen 120 can be Extends substantially to the entire front of the electronic device 10 .

As shown in FIG. 2 , the optical fingerprint module 130 may include a light detection part 134 and an optical component 132 . The light detection part 134 includes a 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 can be manufactured on a chip (Die) through a semiconductor process. , such as optical imaging chips or optical fingerprint sensors. The sensing array 133 is specifically a photo detector array, which includes a plurality of photo detectors distributed in an array, and the photo detectors can be used as the above-mentioned optical sensing unit. The optical component 132 can be arranged above the sensing array 133 of the light detection part 134, and it can specifically include a filter layer (Filter), a light guide layer or an optical path guiding structure, and other optical elements, and the filter layer can be used for The ambient light penetrating the finger is filtered out, and the light guiding layer or light path guiding structure is mainly used to guide the reflected light reflected from the surface of the finger to the sensing array 133 for optical detection.

In some embodiments of the present application, the optical component 132 and the light detection part 134 may be packaged in the same optical fingerprint component. For example, the optical component 132 and the optical detection part 134 can be packaged in the same optical fingerprint chip, or the optical component 132 can be arranged outside the chip where the light detection part 134 is located, for example, the optical component 132 can be attached to the chip. above, or integrate some components of the optical component 132 into the above-mentioned 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 . Wherein, the fingerprint collection area 103 of the optical fingerprint module 130 may be equal to or not equal to the area of the sensing array 133 of the optical fingerprint module 130 or the light sensing range, which is not specifically limited in this embodiment of the present application.

For example, the optical path is guided by light collimation, and 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 that of the optical fingerprint module 130 by, for example, optical path design such as lens imaging, reflective folding optical path design, or other optical path designs such as light convergence or reflection. The area of the sensing array 133 .

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

Taking the optical collimator whose optical path guiding structure includes a through-hole array with a high aspect ratio as an example, the optical collimator may specifically be a collimator (Collimator) layer made on a semiconductor silicon wafer, which has multiple Collimation unit or microhole, the collimation unit can be specifically a small hole, in the reflected light reflected from the finger, the light perpendicularly incident on the collimation unit can pass through and be received by the sensor chip below it, and the incident angle Excessive light is attenuated after multiple reflections inside the collimation unit, so 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 improve the fingerprint quality. recognition effect.

Taking the optical path design of the optical path guiding structure including an optical lens 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 aspheric lenses, which The sensing array 133 is used for converging the reflected light from the finger to the light detecting part 134 below it, so that the sensing array 133 can perform imaging based on the reflected light, thereby obtaining a fingerprint image of the finger. Further, the optical lens layer can also be formed with a pinhole or a micro-aperture diaphragm in the optical path of the lens unit, for example, one or more shading sheets can be formed in the optical path of the lens unit, wherein at least one shading sheet A light-transmitting microhole may be formed on the optical axis or the optical center region of the lens unit, and the light-transmitting microhole may serve as the above-mentioned pinhole or microhole diaphragm. The pinhole or micro-aperture 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, so as to improve the fingerprint imaging effect of the optical fingerprint module 130 .

Taking the optical path design of the optical path guiding structure including a micro-lens (Micro-Lens) layer as an example, the optical path guiding structure may be a micro-lens array formed by a plurality of micro-lenses, which may be formed on the optical path through a semiconductor growth process or other processes. The light detecting part 134 is above the sensing array 133 , and each microlens may correspond to one sensing unit of the sensing array 133 . Moreover, other optical film layers, such as a dielectric layer or a passivation layer, may also be formed between the microlens layer and the sensing unit. More specifically, a light-shielding layer (or called light-shielding layer, light-shielding layer, etc.) with micro-holes (or called openings) may also be included between the micro-lens layer and the sensing unit, wherein the micro-holes are formed in Between the corresponding microlens and the sensing unit, the light blocking layer can block the optical interference between the adjacent microlens and the sensing unit, and make the light corresponding to the sensing unit converge into the microhole through the microlens and It is transmitted to the sensing unit via the micropore for optical fingerprint imaging.

It should be understood that the above several implementation solutions for the light path guiding structure may be used alone or in combination with each other.

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, its specific stacked structure or optical path may need to be adjusted according to actual needs.

On the other hand, the optical assembly 132 can also include other optical elements, such as a filter layer (Filter) or other optical films, which can be arranged between the optical path guiding structure and the optical fingerprint sensor or arranged on the display screen 120 Between the optical path guiding structure and the light path guiding structure, it is mainly used to isolate the influence of external interference light on the optical fingerprint detection. Wherein, 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 separately for each optical fingerprint sensor to filter out interfering light, or a large-area filter layer may be used to simultaneously cover the multiple optical fingerprint sensors.

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

For example, the display screen 120 adopts a display screen with a self-luminous display unit, such as an organic light-emitting diode (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 (ie OLED light source) of the OLED display 120 located in the fingerprint detection area 103 as an excitation light source for optical fingerprint detection. When the finger 140 is pressed on the fingerprint detection area 103, the display screen 120 sends a beam of light 111 to the target finger 140 above the fingerprint detection area 103, and the light 111 is reflected on the surface of the finger 140 to form reflected light or passes through the finger 140. Internal scattering to form scattered light (transmitted light).

In the embodiment of the present application, for the convenience of description, the above-mentioned reflected light and scattered light are collectively referred to as returning light. Because the ridge (ridge) 141 and the valley (valley) 142 of the fingerprint have different light reflection capabilities, therefore, the reflected light 151 from the fingerprint ridge and the reflected light 152 from the fingerprint valley have different light intensities, and the reflected light passes through the optical assembly 132 Afterwards, it is received by the induction array 133 in the optical fingerprint module 130 and converted into a corresponding electrical signal, that is, a fingerprint detection signal; based on the fingerprint detection signal, the fingerprint image data can be obtained, and further fingerprint matching verification can be performed, so that in The electronic device 10 implements an optical fingerprint recognition function.

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

For a liquid crystal display with a backlight module and a liquid crystal panel, in order to support the under-screen fingerprint detection of the liquid crystal display, 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 specifically be an infrared A light source or a light source of non-visible light of a specific wavelength can be arranged under the backlight module of the liquid crystal display or in the edge area under the protective cover of the electronic device 10, and the optical fingerprint module 130 can be provided with a liquid crystal panel or a protective cover Below the edge area of the board 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 can also be arranged under the backlight module, and the backlight module passes through the diffusion sheet, Film layers such as the brightness enhancement sheet and the reflective sheet are provided with openings or other optical designs to allow the fingerprint detection light to pass through the liquid crystal panel and the backlight module and reach the optical fingerprint module 130 . When the optical fingerprint module 130 uses a built-in light source or an external light source to provide optical signals for fingerprint detection, the detection principle is consistent with the above description.

In a specific implementation, the electronic device 10 may further include a transparent protective cover, which may be a glass cover or a sapphire cover, 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 on 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 only include an optical fingerprint sensor. At this time, the fingerprint detection area 103 of the optical fingerprint module 130 has a small area and a fixed position, so the user needs to press the finger to the The specific location of the fingerprint detection area 103, otherwise the optical fingerprint module 130 may not be able to capture the fingerprint image, resulting in poor user experience. In other alternative embodiments, the optical fingerprint module 130 may specifically include a plurality of optical fingerprint sensors. The multiple optical fingerprint sensors can be arranged side by side under the display screen 120 by splicing, and the sensing areas of the multiple optical fingerprint sensors together constitute the fingerprint detection area 103 of the optical fingerprint module 130 . Therefore, 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 usual pressing area of the finger, so as to realize blind-press fingerprint input operation. Further, when the number of optical fingerprint sensors is sufficient, the fingerprint detection area 103 can also be extended to half the display area or even the entire display area, so as to realize half-screen or full-screen fingerprint detection.

With the development of terminal products, the requirements for the performance of fingerprint recognition under the screen are getting higher and higher. However, in some scenarios, there may be a dry finger problem. The contact area between the dry finger and the display screen is very small, and the recognition response area is very small, resulting in discontinuous fingerprints collected, and feature points are easily lost, which affects the performance of fingerprint recognition. . Therefore, the embodiment of the present application provides a fingerprint detection device, which can solve the problem that the current fingerprint recognition scheme has a poor fingerprint recognition effect on dry fingers, that is, can improve the performance of fingerprint recognition on dry fingers.

Specifically, the fingerprint detection device of the embodiment of the present application is suitable for use under the display screen to realize optical fingerprint detection under the screen. The fingerprint detection device in the embodiment of the present application includes a plurality of fingerprint detection units. Any one of the multiple fingerprint detection units will be described in detail below with reference to FIG. 3 to FIG. 8 .

Specifically, FIG. 3 and FIG. 4 both show schematic diagrams of the fingerprint detection unit 20 according to the embodiment of the present application. The fingerprint detection unit 20 may be suitable for the electronic device 10 shown in FIGS. 1 to 2 , or the fingerprint detection unit 20 may be the optical fingerprint module 130 shown in FIGS. 1 to 2 .

As shown in FIGS. 3 and 4 , the fingerprint detection unit 20 may include a microlens array 210 , at least one light blocking layer and an optical sensing pixel array 240 . The microlens array 210 can be arranged under the display screen of an electronic device, the at least one light blocking layer can be arranged under the microlens array 210, and the optical sensing pixel array 240 can be arranged on the at least one light blocking layer. below the layer.

It should be understood that the microlens array 210 and at least one light blocking layer may be the light guide structure included in the optical assembly 132 shown in FIG. The sensing array 133 of each optical sensing unit 131 (also referred to as an optical sensing pixel, a photosensitive pixel, a pixel unit, etc.), will not be described here for brevity.

In the embodiment of the present application, the microlens array 210 may include a plurality of microlenses. For example, as shown in FIG. 3 and FIG. 4 , the microlens array 210 may include a first microlens 211 , a second microlens 212 and a third microlens 213 . The at least one light blocking layer may include a plurality of light blocking layers. For example, as shown in FIGS. 3 and 4 , the at least one light blocking layer may include a first light blocking layer 220 and a second light blocking layer 230 . The optical sensing pixel array 240 may include a plurality of optical sensing pixels, for example, as shown in FIG. 3 and FIG. The sensing pixel 243 , the fourth optical sensing pixel 244 , the fifth optical sensing pixel 245 and the sixth optical sensing pixel 246 .

Optionally, each microlens in the microlens array 210 can be filled with a circle or square; in addition, the material of each microlens in the microlens array 210 can be plastic or glass; the microlens The production process of each microlens in the lens array 210 may be implemented by a micro-nano fabrication process or a compression molding process, which is not limited in the embodiment of the present application.

In the embodiment of the present application, the at least one light blocking layer and the microlens array 210 can be integrated, or the at least one light blocking layer and the optical sensing pixel array 240 can be integrated, and even the microlens array 210, Both the at least one light blocking layer and the optical sensing pixel 240 are integrated into one component, which is not limited in the embodiment of the present application.

Optionally, each microlens in the microlens array 210 can meet at least one of the following conditions: the projection of the light-concentrating surface of the microlens on a plane perpendicular to its optical axis is rectangular or circular; The light-gathering surface of the lens is spherical or aspherical; the curvature of the light-gathering surface of the microlens is the same in all directions; the microlens includes at least one lens; and the focal length range of the microlens is 10um-2mm.

In the embodiment of the present application, the microlens array 210 satisfies at least one of the following conditions: the microlens array 210 is arranged in a polygonal shape and the duty ratio of the microlens array 210 ranges from 100% to 50%. For example, the microlens array 210 is arranged in a square or hexagonal shape. Another example is that the duty cycle of the microlens array 210 is 85%.

In the embodiment of the present application, the period of the microlens array 210 is not equal to the period of the optical sensing pixel array 240, and the period of the microlens array 210 is a rational multiple of the period of the optical sensing pixel array 240, thus avoiding Moiré fringes appear during the fingerprint imaging process and improve the fingerprint recognition effect.

In the embodiment of the present application, the distance between the fingerprint detection unit 20 and the display screen can be configured according to actual applications, for example, it can be set to 20um-1000um to ensure that the fingerprint detection unit 20 has a sufficient safety distance from the display screen , so as to ensure that the fingerprint detection unit 20 will not hit the display screen due to vibration or drop of the electronic device, thereby preventing damage to the device.

It should be understood that at least one light blocking layer in the embodiment of the present application is formed with a plurality of light guide channels corresponding to each micro lens in the microlens array 210, and each light guide channel in the plurality of light guide channels corresponding to each micro lens The included angle between the channel and the optical axis of the corresponding microlens is less than 90°, that is to say, for any microlens, the corresponding plurality of light guide channels are inclined instead of vertical.

It should be noted that the above-mentioned angle may be the angle between the central axis of the light guide channel and the optical axis of the microlens, or the angle between any straight line passing through the light guide channel and the optical axis; in addition, The value range of the included angle can be any range from 0° to 90°, for example, the included angle can be in the range of 15° to 60°, or 10° to 70°, for example, the included angle can be equal to 20°, or may also be equal to 40°, but this embodiment of the present application is not limited thereto.

It should be understood that the angle between the light guide channel and the optical axis of the corresponding microlens can be set to any value not equal to 90° according to practical applications. and the distance between the optical sensing pixel arrays 240 to adjust the size of the included angle between the light guide channel and the optical axis of the corresponding microlens. Since the included angle between the light guide channel and the optical axis of the corresponding microlens is not equal to 90°, the bottoms of multiple light guide channels of the same microlens may be located under the same microlens, or at the bottom of different microlenses. below.

Optionally, for any microlens, the bottoms of the plurality of light guide channels corresponding to the microlens may still be located below the microlens, for example, as shown in FIG. 4 .

Optionally, for any microlens, the bottoms of the plurality of light guide channels corresponding to the microlens may not be located under the microlens, but located under other different microlenses. For example, the bottoms of multiple light guide channels corresponding to the same microlens may respectively extend to the bottom of multiple adjacent micro lenses, for example, as shown in Figure 3; or, the multiple light guide channels corresponding to the same microlens The bottom of each microlens may respectively extend to the bottom of other multiple microlenses that are not adjacent to the microlens, which is not limited in this embodiment of the present application.

It should be understood that, for the sake of illustration, the bottoms of the plurality of light guide channels corresponding to each microlens respectively extend to the bottom of the adjacent plurality of microlenses respectively in combination with FIG. 3 , and in combination with FIG. 4 , each The bottoms of the multiple light guide channels corresponding to the microlens are still located under the microlens as an example. For other cases, the distance between the microlens array 210, at least one light blocking layer and the optical sensing pixel array 240 can be adjusted. Alternatively, it can be realized by adjusting the size of the included angle between the light guide channel and the optical axis of the corresponding microlens. For the sake of brevity, details will not be described here.

Specifically, as shown in FIG. 3, at least one opening is respectively provided in the first light blocking layer 220 and the second light blocking layer 230, so as to form each microlens in the plurality of microlenses (that is, the first The microlens 211 , the second microlens 212 and the third microlens 213 ) correspond to a plurality of light guide channels. Specifically, for the convenience of description, the hole included in the area covered by the position below each microlens is taken as an example for description, which is hereinafter referred to as the coverage area of the microlens. For example, in FIG. 3, the first light blocking layer 220 is provided with a first opening 221 and a second opening 222 within the coverage of the first microlens 211; the first light blocking layer 220 is also provided with a second micro lens The second opening 222 and the third opening 223 within the coverage of the lens 212; the third opening 223 and the fourth opening 224 within the coverage of the third microlens 213 are also arranged in the first light blocking layer 220; For another example, there are similar settings in FIG. 4 , and the specific settings are shown in FIG. 4 , which will not be repeated here.

Similarly, as shown in FIG. 3 , the second light blocking layer 230 is provided with a fifth opening 231 and a sixth opening 232 within the coverage of the first microlens 211; The seventh opening 233 and the eighth opening 234 within the coverage of the second microlens 212; the ninth opening 235 and the tenth opening within the coverage of the third microlens 213 are also arranged in the second light blocking layer 230 236. Similarly, there are similar settings in FIG. 4 , and the specific settings are shown in FIG. 4 , which will not be repeated here.

For the convenience of description, the second microlens 212 is mainly used as an example for description below, but the related descriptions are also applicable to the first microlens 211 and the third microlens 213 . Specifically, as shown in FIG. 3 , the plurality of light guide channels corresponding to the second microlens 212 may include a light guide channel formed by the second opening 222 and the sixth opening 232 , and a light guide channel formed by the third opening 223 and the sixth opening 232 . The light guide channel formed by the ninth opening 235 . In addition, the light guiding channel formed by the second opening 222 and the sixth opening 232 extends to the bottom of the first microlens 211, and the light guiding channel formed by the third opening 223 and the ninth opening 235 extends to the third Below the microlens 213. As shown in FIG. 4 , the plurality of light guide channels corresponding to the second microlens 212 may include: a light guide channel formed by an opening 226 and an opening 233, a light guide channel formed by an opening 226 and an opening 234, and a light guide channel formed by an opening 226 and an opening 234. The light guiding channel formed by the opening 227 and the opening 233 and the light guiding channel formed by the opening 227 and the opening 234 . In addition, the above four light guide channels all extend to the bottom of the second microlens 211 .

It should be understood that the hole corresponding to any one of the microlenses described in the embodiments of the present application refers to a plurality of holes through which its corresponding light guide channel passes. For example, the hole corresponding to the second microlens 212 refers to its light guide channel. A plurality of holes passed through, for example, the holes corresponding to the second microlens 212 in FIG. Six openings 232, the third opening 223 and the ninth opening 235; for another example, the holes corresponding to the second microlens 212 in FIG. 227 , opening 233 and opening 234 .

Further, an optical sensing pixel may be disposed below each of the plurality of light guide channels corresponding to each micro lens in the microlens array 210 .

Still taking the second microlens 212 in FIG. 3 as an example, a second optical sensing pixel 242 is arranged below the light guide channel formed by the second opening 222 and the sixth opening 232, and the second optical sensing pixel 242 is formed by the third opening 223 and the sixth opening 232. A fifth optical sensing pixel 245 is disposed below the light guide channel formed by the ninth opening 235 . For the second microlens 221 in FIG. 4 , a third optical sensing pixel 243 is arranged below the light guiding channel formed by the opening 226 and the opening 233 and the light guiding channel formed by the opening 227 and the opening 233; Fourth optical sensing pixels 244 are disposed below the light guiding channel formed by the opening 226 and the opening 234 and the light guiding channel formed by the opening 227 and the opening 234 .

Furthermore, a plurality of optical sensing pixels are arranged under each microlens in the microlens array 210, and the plurality of optical sensing pixels arranged under each microlens are respectively used to receive The optical signal transmitted through the corresponding light guide channel is used to detect the fingerprint information of the finger. That is to say, for any microlens, if the bottoms of the plurality of light guide channels corresponding to the microlens are still located under the microlens, the plurality of optical sensing pixels arranged under the microlens are used to receive the light passing through the microlens respectively. The light signals that are collected by the lens and transmitted through the corresponding multiple light guide channels; or, if the bottoms of the multiple light guide channels corresponding to the microlens extend below the adjacent multiple microlenses, the microlens The plurality of optical sensing pixels disposed below are respectively used to receive light signals converged by a plurality of adjacent microlenses and transmitted through corresponding light guide channels.

Still taking the second microlens 212 in FIG. 3 as an example, two optical sensing pixels are arranged in the range directly below the coverage of the second microlens 212 in FIG. 3 , that is, the second microlens 212 A third optical sensing pixel 243 and a fourth optical sensing pixel 244 may be provided below, wherein the third optical sensing pixel 243 may be used to receive light collected by the first microlens 211 and pass through the second opening 222 and the seventh optical sensing pixel. The oblique optical signal transmitted by the light guide channel formed by the opening 233, the fourth optical sensing pixel 244 can be used to receive the light signal converged by the third microlens 213 and pass through the guide channel formed by the third opening 223 and the eighth opening 234. The optical channel transmits oblique optical signals, and the first microlens 211 and the third microlens 213 are both adjacent to the second microlens 212 .

For another example, as shown in FIG. 4 , still taking the second microlens 212 as an example, two optical sensing pixels are arranged in the range directly below it, that is, a third optical sensing pixel can be arranged under the second microlens 212 . Sensing pixel 243 and fourth optical sensing pixel 244, wherein, the third optical sensing pixel 243 can be used to receive light collected by the second microlens 212 and transmitted through the light guide channel formed by the opening 226 and the opening 233 The oblique optical signal, the third optical sensing pixel 243 can also be used to receive the oblique optical signal collected by the second microlens 212 and transmitted through the light guide channel formed by the opening 227 and the opening 233; similarly, the The fourth optical sensing pixel 244 can be used to receive the inclined light signal converged by the second microlens 212 and transmitted through the light guide channel formed by the opening 226 and the opening 234, and the fourth optical sensing pixel 244 can also be used for The oblique light signal converged by the second microlens 212 and transmitted through the light guide channel formed by the opening 227 and the opening 234 is received.

In addition, the number of multiple optical sensing pixels under each microlens in the microlens array 210 can be set according to actual applications. For example, in the embodiment of the present application, 4 optical sensing pixels are set under each microlens as For example; or, the bottom of each microlens may also correspond to 9 optical sensing pixels, or other numbers may also be set, and the embodiment of the present application is not limited thereto. In addition, the distribution of multiple optical sensing pixels under each microlens may be polygonal. For example, the polygon includes, but is not limited to, a rectangle or a rhombus. For another example, the distribution of the plurality of optical sensing pixels under each microlens in the microlens array 210 may be circular or elliptical.

Since the microlenses in the microlens array are distributed in an array, when the distribution of multiple optical sensing pixels under each microlens is polygonal, the correspondence between the microlens array and the optical sensing array can be effectively simplified, and further The structural design of the fingerprint detection unit is simplified. Specifically, FIG. 5 and FIG. 6 are two schematic top views of the second microlens 212 shown in FIG. 3 or FIG. 4 , respectively. As shown in Figures 5 and 6, it is assumed here that four optical sensing pixels can be arranged below the second microlens 212, wherein the distribution of the four optical sensing pixels in Figure 5 is rectangular, and the four microlenses in Figure 6 The distribution of can be presented as a diamond.

It should be noted that, the embodiment of the present application does not limit the specific correspondence manner between each microlens and the optical sensing pixels below it. Taking the third photosensitive pixel 243 below the second microlens 212 as an example, the second microlens 212 may cover part or all of the photosensitive area (AA) of the third photosensitive pixel 243 . Preferably, taking the light guide channel in FIG. 3 as an example, the second microlens 212 can cover the light collected by the first microlens 211 in the photosensitive area (PD area, AA) of the third optical sensing pixel 243 and passed through the second microlens. The area that can be irradiated by the oblique optical signal transmitted by the light guide channel formed by the second opening 222 and the seventh opening 233, such as the oblique shaded area in each photosensitive area in Fig. 5 and Fig. 6, to ensure that the third optical sensing The pixels 243 can receive enough light signals to improve the fingerprint identification effect.

The design of multiple light guide channels corresponding to each microlens will be described in detail below.

In some embodiments of the present application, the plurality of light guide channels corresponding to each microlens in the microlens array 210 may be distributed centrally symmetrically along the optical axis direction of the same microlens. By arranging a plurality of light guide channels corresponding to each microlens in a centrosymmetric manner, the process complexity of the fingerprint detection unit can be reduced, that is, the process complexity of the entire fingerprint detection device can be reduced.

Still taking the second microlens 212 in FIG. 3 as an example, as shown in FIG. The light guide channel below the microlens, the two are symmetrical to the center along the optical axis direction of the second microlens 212; among the plurality of light guide channels of the second microlens 212, the light guide channel that can extend to the bottom of the upper left corner microlens and The light guide channel that can extend to the lower right corner of the micro-lens is also center-symmetrical along the optical axis direction of the second micro-lens 212 . The light guide channel in FIG. 4 is also similar, and for the sake of brevity, details are not repeated here.

In some embodiments of the present application, each of the plurality of light guide channels corresponding to each microlens in the microlens array 210 may form a preset angle with the first plane, so that each microlens A plurality of optical sensing pixels disposed under the lens are respectively used to receive light signals converged by one or more microlenses and transmitted through corresponding light guide channels, wherein the first plane is a plane parallel to the display screen. The preset included angle can ensure that the bottom ends of the plurality of light guide channels corresponding to each microlens respectively extend to the bottom of the same microlens or extend to the bottom of a plurality of adjacent microlenses.

As shown in FIGS. 3 and 5 , still taking the second microlens 212 as an example, the plane where the optical sensing pixel array 240 is located is parallel to the first plane, and the second opening 222 and the sixth opening 232 form The light guiding channel forms a first angle with the plane where the optical sensing pixel array 240 is located, and the light guiding channel formed by the third opening 223 and the ninth opening 235 forms a second angle with the plane where the optical sensing pixel array 240 is located. angle. Wherein the first angle is equal to the second angle. Of course, in other alternative embodiments, the first angle may not be equal to the second angle, which is not limited in this embodiment of the present application. Moreover, the light guide channel in FIG. 4 is also similar, and for the sake of brevity, details are not repeated here.

It should be noted that the preset angle may be the angle between the central axis of the light guide channel and the first plane, or the angle between any straight line passing through the light guide channel and the first plane; in addition, The range of the preset included angle may be any range from 0° to 90°, for example, the range of the preset included angle may be from 15° to 60°, or from 10° to 70°. Be specific.

In some embodiments of the present application, the projections of the plurality of light guide channels corresponding to each microlens in the microlens array 210 on the first plane may be center-symmetrical to the projection of the optical axis of the same microlens on the first plane. distribution, so as to ensure that each optical sensing pixel in the optical sensing pixel array 240 can receive enough light signals, thereby improving the resolution of the fingerprint image and the fingerprint recognition effect.

As shown in Figures 3 and 5, still taking the second microlens 212 as an example, since each light guide channel is an inclined channel, the end face of each light guide channel on the first plane is elliptical, and the The four light guide channels corresponding to the second microlens 212 are symmetrically distributed along the projection center of the optical axis of the second microlens 212 on the first plane near the end face of the optical sensing pixel array 240 .

The implementation of at least one light blocking layer in the fingerprint detection unit 20 will be described in detail below.

In some embodiments of the present application, the fingerprint detection unit 20 may include a plurality of light-blocking layers, and at least one opening corresponding to each microlens is provided in different light-blocking layers to form a plurality of holes corresponding to the microlens. Light guide channel. For example, the at least one light blocking layer may include the first light blocking layer 220 and the second light blocking layer 230 described above with respect to FIG. 3 or FIG. 4 . For another example, in addition to the two light-blocking layers described in Figures 3 and 4, the fingerprint detection unit 20 may also include more light-blocking layers, taking Figure 3 as an example, correspondingly, Figure 7 is the embodiment of the present application Another schematic structural diagram of the fingerprint detection unit 20. As shown in FIG. 7 , the fingerprint detection unit 20 may include a third light blocking layer 260 in addition to the first light blocking layer 220 and the second light blocking layer 230 shown in FIG. 3 , wherein the third light blocking layer The layer 260 includes an eleventh opening 261 , a twelfth opening 262 and a thirteenth opening 263 . For the convenience of description, the following description mainly takes FIG. 3 and FIG. 7 as examples.

In some implementations, the number of openings corresponding to the same microlens in different light blocking layers may be the same, for example as shown in FIG. 4; or the number of openings corresponding to the same microlens in different light blocking layers is determined by It can be increased or decreased sequentially from top to bottom to form a plurality of light guide channels corresponding to each microlens.

Take the example that the number of openings corresponding to the same microlens in different light-blocking layers can increase sequentially from top to bottom. In other words, the distance between the openings in different light-blocking layers can be sequentially increased from top to bottom decrease. For example, as shown in FIG. 3 , the distance D between two adjacent openings in the first light blocking layer 220 is greater than the distance d between two adjacent openings in the second light blocking layer 230 . The upper part of the light-shielding layer with a lower density of openings in the plurality of light-shielding layers shields most of the undesired optical signals received by the fingerprint detection unit, and passes through the upper part of the plurality of light-shielding layers with a lower density of openings. The partial light-shielding layer and the lower part of the light-shielding layer with higher hole density can form a plurality of light-guiding channels corresponding to each microlens. In addition, the manufacturing complexity of the at least one light-shielding layer can be reduced and the strength of the upper part of the light-shielding layer can be increased.

In the embodiment of the present application, a plurality of openings corresponding to each microlens may be provided in the bottom light blocking layer of the plurality of light blocking layers, and a plurality of light guiding channels corresponding to each micro lens respectively pass through the bottom layer A plurality of openings corresponding to the same microlens in the light blocking layer. For example, as shown in FIGS. 3 and 7 , still taking the second microlens 212 as an example, the second light blocking layer 230 is provided with a sixth opening 232 and a ninth opening 235 corresponding to the second microlens 212 , two light guiding channels of the plurality of light guiding channels of the second microlens 212 pass through the sixth opening 232 and the ninth opening 235 respectively.

In the embodiment of the present application, the top light-blocking layer of the plurality of light-blocking layers may be provided with an opening on the optical axis of each microlens, and the plurality of light-guiding channels corresponding to the microlens all pass through the top layer The opening corresponding to the microlens in the light blocking layer. For example, as shown in FIG. 7, for the second microlens 212, the third light-blocking layer 260 can be provided with a twelfth opening at a position close to the first light-blocking layer 220 in the direction of the optical axis of the second microlens 260. Hole 262. At this time, one light guiding channel corresponding to the second microlens 212 passes through the twelfth opening 262 , the second opening 222 and the sixth opening 232 , and the other light guiding channel corresponding to the second microlens 212 Pass through the twelfth opening 262 , the third opening 223 and the ninth opening 235 , that is, the two light guide channels of the second microlens 212 all pass through the twelfth opening 262 .

In the embodiment of the present application, for the case where the bottoms of the plurality of light guide channels corresponding to the same microlens extend to the bottom of the adjacent microlens, the non-bottom light blocking layer in the plurality of light blocking layers is placed on the bottom of the plurality of microlenses. The middle position of the back focus of two adjacent microlenses can be provided with an opening, then the two light guide channels corresponding to the two adjacent microlenses all pass through the adjacent The openings corresponding to the two microlenses.

For example, as shown in Figure 3 and Figure 7, for the second microlens 212, the first light-blocking layer 220 can be set at the middle position of the back focus of the first microlens 211 and the back focus of the second microlens 212 The second opening 222, and each of the first microlens 211 and the second microlens 212 has a light guide channel that will pass through the second hole 222; similarly, the first light blocking layer 220 is in the third microlens 213 and the middle position of the second microlens 212's back focus can be provided with a third opening 223, and the third microlens 213 and the second microlens 212 each have a light guide channel that will pass through the The third opening 223 .

In other implementations, the apertures of the openings in different light-blocking layers corresponding to the same microlens can also increase, decrease, or remain unchanged from top to bottom, so as to screen out the optical sensing pixel array 240 that is expected to receive received light signal.

For example, as shown in FIG. 7 , for a top-down three-layer light-shielding layer, the aperture of the opening in the third light-shielding layer 260 of the upper layer is larger than that of the opening in the first light-shielding layer 220 of the middle layer. Apertures, the apertures of the openings in the first light blocking layer 220 of the middle layer are larger than the apertures of the openings in the second light blocking layer 230 of the lower layer.

Optionally, the fingerprint detection unit 20 includes two or three light-blocking layers as an example for illustration. Similarly, the fingerprint detection unit 20 may also include more light-blocking layers, or the fingerprint detection The unit 20 may also include only one light-shielding layer, and this embodiment of the present application is not limited thereto.

For example, in the case where the fingerprint detection unit 20 only includes one light-blocking layer, a plurality of inclined through holes can be arranged on the light-blocking layer at this time, that is, a plurality of light-guiding channels of any one microlens can provide the light-blocking channel for the light-blocking layer. A plurality of inclined through holes corresponding to the microlenses on the layer. For example, the thickness of the one light blocking layer is greater than the preset threshold, so that the plurality of optical sensing pixels arranged under each microlens are respectively used to receive the light collected by the same microlens or by a plurality of adjacent microlenses. The optical signal transmitted through the corresponding light guide channel.

Optionally, the fingerprint detection unit 20 of the embodiment of the present application may further include a transparent medium layer 250 . Wherein, as shown in FIG. 3 , FIG. 4 and FIG. 7 , the transparent medium layer 250 can be arranged in at least one of the following positions: between the microlens array 210 and the at least one light-blocking layer, the at least one light-blocking layer between the layers, and between the at least one light blocking layer and the optical sensing pixel array 240 .

For example, as shown in FIGS. 3 and 4 , the transparent medium layer 250 may include a first medium layer 251 between the microlens array 210 and the at least one light-blocking layer (ie, the first light-blocking layer 220 ) and The second medium layer 252 is between the first light blocking layer 220 and the second light blocking layer 230 .

For another example, as shown in FIG. 7 , the transparent medium layer 250 may include: a first medium layer 251 and three layers located between the microlens array 210 and the at least one light-blocking layer (ie, the third light-blocking layer 260 ). The second medium layer 252 between the two light-blocking layers, wherein the second medium layer 252 includes the second medium layer 252 between the third light-blocking layer 260 and the first light-blocking layer 220 and the first light-blocking layer 220 and the second medium layer 252 between the second light blocking layer 230 .

The material of the transparent medium layer 250 is any transparent material that is transparent to light, such as glass, and may also be made of air or vacuum, which is not specifically limited in this application.

Optionally, the fingerprint detection unit 20 of the embodiment of the present application may further include a filter layer. FIG. 8 is another schematic structural diagram of the fingerprint detection unit 20 of the embodiment of the present application. As shown in FIG. 8, the fingerprint detection unit 20 may also include a filter layer 270, which may be arranged at the following positions: At least one place: above the microlens array 210, between the microlens array 210 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 240 between. For example, the filter layer 270 can be disposed between the optical sensing pixel array 240 and the second light blocking layer 230 . For example, the filter layer 270 may be the filter layer in the optical component 132 mentioned above.

The filter layer 270 can be used to reduce unwanted ambient light in fingerprint sensing, so as to improve the optical sensing of the optical sensing pixel array 240 to the received light. The filter layer 270 can specifically be used to filter out light of a specific wavelength, for example, near-infrared light and part of red light. For example, human fingers absorb most of the energy of light with wavelengths below 580nm, if one or more optical filters or optical filter layers are designed to filter light with wavelengths from 580nm to infrared, the impact of ambient light on fingerprints can be greatly reduced Influence of optical detection in sensing.

For example, the filter layer 270 may include one or more optical filters configured, for example, as a bandpass filter to allow transmission of light emitted by the OLED screen while blocking infrared light from sunlight and other light components. This optical filtering can effectively reduce background light caused by sunlight when the under-screen fingerprint detection unit 20 is used outdoors. One or more optical filters may be implemented, for example, as optical filter coatings formed on one or more continuous interfaces, or may be implemented as one or more discrete interfaces. It should be understood that the filter layer 270 can be fabricated at any position along the optical path from the reflected light formed by finger reflection to the optical sensing pixel array 240 , which is not specifically limited in this embodiment of the present application.

In addition, the light-incoming surface of the filter layer 270 may be provided with an optical inorganic coating or an organic blackening coating, so that the reflectance of the light-incoming surface of the filter layer 270 is lower than a first threshold, such as 1%, so as to ensure The optical sensing pixel array 240 can receive sufficient light signals, thereby improving the fingerprint identification effect.

Take the filter layer 270 fixed on the upper surface of the optical sensing pixel array 240 by a fixing device as an example. The filter layer 270 and the photosensitive pixel array 240 can be glued on the non-photosensitive area of the photosensitive pixel array 240 , and there is a gap between the filter layer 270 and the photosensitive area of the photosensitive pixel array 240 . Alternatively, the lower surface of the filter layer 270 is fixed on the upper surface of the optical sensing pixel array 240 by glue whose refractive index is lower than a preset refractive index, for example, the preset refractive index includes but is not limited to 1.3.

Therefore, the fingerprint detection device of the embodiment of the present application includes a plurality of fingerprint detection units, and each fingerprint detection unit is set based on the above technical solution, which can at least solve the following technical problems: 1. The recognition effect of the vertical light signal on the dry finger is too poor Problems; 2. The problem of too long exposure time of the single-object telecentric microlens array scheme; 3. The problem of excessive thickness of the fingerprint detection device; 4. The problem of poor tolerance tolerance of the fingerprint detection device; 5. Fingerprint detection Problem with oversized device.

For problem 1, by designing multiple light guide channels for each microlens, and making the angle between each of the multiple light guide channels corresponding to each microlens and the optical axis of the corresponding microlens If it is less than 90°, correspondingly, multiple optical sensing pixels under each microlens can respectively receive oblique optical signals gathered from the same microlens or multiple adjacent microlenses and transmitted through corresponding light guide channels, Therefore, the fingerprint information of the dry finger can be detected by using the inclined light signal. When the dry hand fingerprint is not in good contact with the OLED screen, the contrast between the fingerprint ridges and fingerprint valleys of the fingerprint image in the vertical direction is poor, and the image is blurred to the point that the fingerprint lines cannot be distinguished. This application uses a reasonable optical path design to allow the optical path to receive optical signals in an oblique direction , 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, plastering fingers, low temperature and other scenarios, fingers are usually dry and their cuticles are uneven. When they are pressed on the OLED screen, poor contact will occur in some areas of the finger. The emergence of this situation causes the current optical fingerprint scheme to be ineffective in identifying dry hand fingerprints. The beneficial effect of this application is to improve the imaging effect of dry hand fingerprints and make the image of dry hand fingerprints clearer.

In addition, the optical sensing pixel array 240 can also expand the viewing angle and field of view of the optical sensing pixel array 240 by receiving the inclined light signal. For example, the field of view of the fingerprint detection unit 20 that can receive inclined light can be expanded from 6x9mm ^to 7.5x10.5mm ² , which further improves the fingerprint recognition effect.

Moreover, a plurality of optical sensing pixels are arranged under each microlens, so that the spatial period of the lens array 210 is not equal to that of the optical sensing pixel array 240, thereby avoiding moiré fringes in the fingerprint image and improving the fingerprint identification effect.

For problem 2, by designing multiple light guide channels for each microlens, and each light guide channel corresponds to an optical sensor pixel to receive the optical signal passing through the light guide channel, that is, a single microlens and multiple optical channels can be formed. The imaging light path matched with the sensing pixels. That is, the optical signals of multiple angles can be multiplexed through a single microlens (for example, as shown in Figure 5 or Figure 6, the optical signals of 4 angles can be multiplexed through a single microlens), so that different object apertures can be The light beams of different angles are segmented and imaged, which effectively increases the amount of light entering each fingerprint detection unit, which also increases the light entering amount of the fingerprint detection device, thereby reducing the exposure time of the optical sensing pixel array. It should be noted that the aperture angle is the angle formed by the object point on the optical axis of the microlens and the effective diameter of the front lens of the microlens. The larger the aperture angle of the microlens, the greater the amount of light entering the microlens. The effective diameter of the lens is directly proportional to the distance from the focal point.

Specifically, since a plurality of optical sensing pixels under each microlens can respectively receive the inclined optical signals transmitted by the corresponding light guide channel, the optical sensing pixel array can be divided into multiple optical sensing pixel arrays according to the direction of the light guide channel. Sensing pixel groups, wherein each optical sensing pixel in each optical sensing pixel group is used to receive an oblique light signal in the same direction as the direction of the light guide channel corresponding to the same optical sensing pixel group, that is, each optical sensing pixel group can be based on The received oblique optical signal generates a fingerprint image, 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 fingerprint image A high-resolution fingerprint image, and then perform fingerprint identification based on this high-resolution fingerprint image.

Referring to FIG. 5 or FIG. 6, the optical sensing pixel array 240 can collect oblique light signals to the 4 optical sensing pixels through the 4 light guide channels corresponding to each microlens, that is, the optical sensing pixel array 240 can be divided into 4 optical sensing pixel groups are used to form 4 fingerprint images. Based on these 4 fingerprint images, a fingerprint image with higher resolution can be obtained, thereby improving the fingerprint recognition effect.

It can be seen that, since each microlens can gather oblique light signals in multiple directions through multiple light guide channels, or the optical sensing pixel array can simultaneously acquire multiple fingerprint images through optical path design, even if the optical sensing pixel array is reduced The exposure time of the array leads to a lower resolution of each fingerprint image, and a fingerprint image with a higher resolution can also be obtained by processing multiple fingerprint images with lower resolution.

That is to say, based on the above technical solution, it is possible to reduce the exposure time of the optical sensing pixel array 240 (ie, the image sensor) while ensuring the fingerprint recognition effect.

For problem 3, the imaging optical path combined with a single microlens and multiple optical sensing pixels can perform non-frontal light imaging (that is, oblique light imaging) of the object-side beam of the fingerprint under the screen, especially the multiple The optical sensing pixels are respectively used to receive light signals converged by a plurality of adjacent microlenses, thereby expanding the object-side numerical aperture of the optical system and shortening the optical path design of the optical sensing pixel array (that is, the at least one light blocking layer) Finally, the thickness of each fingerprint detection unit can be effectively reduced, which also reduces the thickness of the fingerprint detection device.

For problem 4, the imaging optical path combined with a single microlens and multiple optical sensing pixels can perform non-frontal imaging of the object-side beam of the fingerprint under the screen, which can expand the object-side numerical aperture of the optical system, thereby improving the robustness of the system And the tolerance tolerance of the fingerprint detection unit 20 . The numerical aperture may be the product of the refractive index (h) of the medium between the front lens of the microlens and the object to be inspected and the sine of the half of the aperture angle (u).

For problem 5, through the imaging optical path of a single microlens and multiple optical sensing pixels and the light guide channel set in the at least one light-blocking layer, the optical sensing can be improved while ensuring that two adjacent optical sensing pixels do not affect each other. The density of the optical sensing pixels in the sensing pixel array 240 can further reduce the size of each fingerprint detection unit, thus reducing the size of the fingerprint detection device.

As can be seen from the above, the technical solution of the present application can make the optical sensing pixel array 240 only receive optical signals at oblique angles through a reasonable design of multiple light guide channels corresponding to each microlens, and converge multiple angles through a single microlens. The oblique optical signal solves the problem of too long exposure time of the single-object telecentric microlens array scheme. In other words, the fingerprint detection unit 20 can not only solve the problem that the recognition effect of the vertical light signal on the dry finger is too poor and the problem that the exposure time of the single-object telecentric microlens array solution is too long, but also solve the problem of multiple fingerprint detection. The fingerprint detection device of the unit is too thick, the tolerance tolerance is too bad, and the size is too large.

In the embodiment of the present application, the fingerprint detection device includes a plurality of fingerprint detection units, and each fingerprint detection unit can receive multiple oblique lights in different directions. For example, the above-mentioned fingerprint detection unit 20 as shown in FIGS. For light in different oblique directions, the inclination angles of each direction can be the same or different.

Assuming that the fingerprint detection device under the screen only includes one fingerprint detection unit, which can be used to receive oblique light from multiple directions, at this time, the effective imaging field of view of the single fingerprint detection unit will be at its vertical The direction is offset outward by a certain distance. For example, FIG. 9 shows a schematic diagram of the field of view of a single fingerprint detection unit. As shown in FIG. 9, the electronic device includes a display screen 310, and a single fingerprint detection unit is included below the display screen 310. The fingerprint detection unit 20 in FIGS. 3 to 8 can receive light from four different oblique directions. As shown in Figure 9, since the fingerprint detection unit can receive light in an oblique direction, the size of the upper surface of the fingerprint detection unit (or the field of view of the fingerprint detection unit) will be smaller than the fingerprint detection area 311 above the display screen 310 The area of the effective area, that is to say, the size of the entire fingerprint detection unit will expand the field of view of ΔL to the edge of the fingerprint detection unit relative to the field of view range of the fingerprint detection area 311 on the display screen 310 . Wherein, the fingerprint detection area 311 included in the display screen 310 is used to provide a touch interface for the user to perform fingerprint identification, and its effective area can also be referred to as the field of view of the fingerprint detection unit in the fingerprint detection area 311, or as the fingerprint detection area The field of view of 311 refers to the effective touch range when a finger is touched for fingerprint identification. It should be understood that the expanded field of view is proportional to the distance between the upper surface of the screen and the upper surface of the fingerprint detection unit.

Specifically, FIG. 10 shows a schematic diagram of the calculation method of the field of view of a single fingerprint detection unit in the embodiment of the present application. As shown in FIG. 10 , the size of the entire fingerprint detection unit 20 is relative to the fingerprint detection area on the display screen 310 The field of view of 311 will expand the field of view of ΔL to the edge of the fingerprint detection unit, and the ΔL can be calculated by the following formula (1):

ΔL＝h ₁ tanθ ₁ +h ₂ tanθ ₂ (1)

Wherein, as shown in Figure 10, h ₁ is the thickness of display screen 310; θ ₁ is the deflection angle that light propagates in display screen 310; h ₂ is the thickness of the gap between fingerprint detection unit 20 and display screen 310; θ ₂ is the deflection angle of the light propagating in the gap, for example, when the gap is air, the _θ2 is the deflection angle of the light propagating in the air. Optionally, the θ ₁ and θ ₂ satisfy the formula n ₁ sin θ ₁ = n ₂ sin θ ₂ , n ₁ represents the refractive index of the display screen 310, and n ₂ represents the refractive index of the gap between the fingerprint detection unit 20 and the display screen 310 , for example, if the gap is air, then the n ₂ represents the refractive index of air.

For example, assuming that the fingerprint detection unit receives light from four different oblique directions, each direction has an angle of 40° in the air, and the display screen 310 is an OLED screen with a thickness of 1.4mm. At this time, when the fingerprint detection unit 20 is installed under the display screen 310 , by adjusting the distance between the fingerprint detection unit 20 and the display screen 310 , the expanded field of view of the fingerprint detection unit can be adjusted to ΔL=0.75mm.

Usually, the smaller the chip of the fingerprint detection unit is, the larger the ratio of its expanded field of view is. For example, assuming that the minimum size of a fingerprint detection unit is 2.3mmx2.3mm, which may be the size of a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) photosensitive area, then the optical path through the fingerprint detection unit involves, It will expand the effective area of its field of view to 3.8mm*3.8mm, and the entire field of view will be expanded to nearly 2.7 times.

According to the experience of using the fingerprint under the screen, usually the effective area of the optical fingerprint under the screen is greater than or equal to the effective field of view of 6mmx6mm, and its recognition effect is better, that is to say, the effective area of the fingerprint detection area 311 included in the display screen 310 is usually greater than or equal to Equal to 6mmx6mm, the fingerprint detection area 311 is used to provide a touch interface for the user to perform fingerprint identification. In order to obtain as many fields of view as possible with a chip area as small as possible, an embodiment of the present application provides a fingerprint detection device, which realizes a larger field of view by physically splicing multiple fingerprint detection units.

Specifically, the fingerprint detection device of the embodiment of the present application includes a plurality of fingerprint detection units. FIG. 11 shows a schematic diagram of the electronic device 300 of the embodiment of the present application. As shown in FIG. 11 , the electronic device 300 includes a display screen 310, the The display screen 310 includes a fingerprint detection area 311, which is used to provide a touch interface for users to perform fingerprint identification. A fingerprint detection device is arranged below the display screen 310. The fingerprint detection device includes a plurality of fingerprint detection units, for example, the plurality of fingerprint detection units Any one of the fingerprint detection units may be the above-mentioned fingerprint detection unit 20 .

Specifically, the size of each fingerprint detection unit among the plurality of fingerprint detection units and the distance between two adjacent fingerprint detection units are set according to a size parameter, and the size parameter includes at least one of the following parameters: each The field of view range of the fingerprint detection unit (that is, including the total area of the field of view that the fingerprint detection unit can expand), the area of the fingerprint detection area, the thickness of the display screen, and the optical path from the surface of each fingerprint detection unit to the display distance from the top surface of the screen.

It should be understood that the structures or sizes of the multiple fingerprint detection units included in the fingerprint detection device in the embodiments of the present application may be the same or different. Specifically, any one of the multiple fingerprint detection units can be the fingerprint detection unit 20 of the above-mentioned Fig. 3 to Fig. 8, but the multiple fingerprint detection units can be fingerprint detection units with the same or different structures It can be fingerprint detection units with the same size or different sizes. For example, in order to facilitate production and processing, the structure and size of the plurality of fingerprint detection units can be set to be exactly the same, for example, the plurality of fingerprint detection units can be the fingerprint detection unit 20 shown in Figure 3 or Figure 7, but this The application embodiments are not limited thereto.

In the embodiment of the present application, the multiple fingerprint detection units included in the fingerprint detection device may be arranged as an n*m matrix, where n and m are positive integers. Among the multiple fingerprint detection units, the distances between the multiple fingerprint detection units located in the same row are equal; and/or, among the multiple fingerprint detection units, the distances between the multiple fingerprint detection units located in the same column are equal.

Optionally, the arrangement of multiple fingerprint detection units in this embodiment of the present application will be described in detail below in conjunction with specific embodiments.

Optionally, as a first embodiment, the fingerprint detection device may include two fingerprint detection units.

Optionally, the two fingerprint detection units can be arranged side by side, and can also be arranged side by side up and down. For example, FIG. 12 shows a schematic diagram of the arrangement of two fingerprint detection units according to the embodiment of the present application. As shown in FIG. 12 , it is assumed here that two rectangular fingerprint detection units are arranged side by side. Each fingerprint detection unit may be the fingerprint detection unit 20 shown in FIGS. 3 to 8 above.

Specifically, as shown in Figure 12, the width of the fingerprint detection unit is represented as W here, the length is represented as H, and the horizontal distance between two fingerprint detection units is represented as G, the two fingerprint detection units in this Figure 12 The surrounding rectangular frame can represent the effective range of the fingerprint detection area, which is larger than the area of the fingerprint detection unit. Optionally, the actual area of the fingerprint detection area may be larger than its effective range, and the effective range represents the minimum area that can be used for fingerprint identification. For example, other functional areas may also be set in the fingerprint detection area. Not limited to this.

It should be understood that, as shown in Figure 12, according to the size of the field of view of each fingerprint detection unit on the upper surface of the display screen, in the case of two fingerprint detection units, by setting the sizes of W, H and G reasonably, It can be made to meet the requirements of the effective area size of the fingerprint detection area.

Specifically, the size parameter includes: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least a first value X (that is, ΔL is greater than or equal to the first value X) at the edge of each fingerprint detection unit. value X), and the length of the fingerprint detection area is greater than or equal to the second value Y, and the width of the fingerprint detection area is greater than or equal to the third value Z, then with reference to Figure 12, the following parameters can be set correspondingly: each The length H of each fingerprint detection unit is greater than or equal to Y-2X, the width W of each fingerprint detection unit is greater than or equal to 0.5Z-2X, and the horizontal distance G between the two fingerprint detection units is less than or equal to 2X.

For example, it is assumed that the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least 0.75mm (that is, ΔL is greater than or equal to 0.75mm) at the edge of each fingerprint detection unit, and the fingerprint detection unit The area of the area is greater than or equal to 6mm*6mm, then referring to Figure 12, the following parameters can be set correspondingly: the length H of each fingerprint detection unit is greater than or equal to 4.5mm, the width W of each fingerprint detection unit is greater than or equal to 1.5mm, The horizontal distance G between the two fingerprint detection units is less than or equal to 1.5 mm. For example, the length H of each fingerprint detection unit is set to 6mm, the width W of each fingerprint detection unit is set to 2.3mm, and the horizontal distance G between the two fingerprint detection units is set to 1mm, then according to the above parameter settings, the corresponding The effective field of view or effective area of the fingerprint recognition area is 7.1mm*7.5mm.

For another example, assume that the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least 0.6mm outside the edge of each fingerprint detection unit (that is, ΔL is greater than or equal to 0.6mm), and the fingerprint The area of the detection area is greater than or equal to 6mm*6mm, then referring to Figure 12, the following parameters can be set correspondingly: the length H of each fingerprint detection unit is greater than or equal to 4.8mm, and the width W of each fingerprint detection unit is greater than or equal to 1.8mm , the horizontal distance G between the two fingerprint detection units is less than or equal to 1.2 mm. For example, the length H of each fingerprint detection unit is set to 6.5mm, the width W of each fingerprint detection unit is set to 2.6mm, and the horizontal distance G between the two fingerprint detection units is set to 1mm, then according to the above parameter settings, The effective field of view or effective area of the corresponding fingerprint identification area is 7.4mm*7.7mm.

For another example, assume that the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least 0.3mm outside the edge of each fingerprint detection unit (that is, ΔL is greater than or equal to 0.3mm), and the fingerprint The area of the detection area is greater than or equal to 6mm*6mm, then referring to Figure 12, the following parameters can be set correspondingly: the length H of each fingerprint detection unit is greater than or equal to 5.4mm, and the width W of each fingerprint detection unit is greater than or equal to 2.4mm , the horizontal distance G between the two fingerprint detection units is less than or equal to 0.6 mm.

It should be understood that the distance ΔL of the field of view of each fingerprint detection unit on the upper surface of the display screen relative to the edge of each fingerprint detection unit can be calculated according to the formula (1) through parameters h ₁ , h ₂ , θ ₁ and _θ2 , and the range of ΔL can be set according to the actual application, for example, the above-mentioned 0.6mm or 0.75mm can be set, or it can be set to a larger or smaller value, for example, usually set ΔL greater than or equal to 0.3mm. For example, assuming that the thickness h ₁ of the display screen is 1.4mm, and the deflection angle θ ₂ of the light propagating in the air is 40°, by adjusting the vertical distance h ₂ from the upper surface of the optical path of the fingerprint detection unit to the display screen, ΔL can reach 0.6mm, or up to 0.75mm; as another example, assuming that the vertical distance h ₁ + h ₂ from the optical path surface of each fingerprint detection unit to the upper surface of the display screen is 1.6mm, the deflection angle θ ₂ of light propagating in the air It is 20°, which can also make ΔL reach 0.6mm.

Therefore, according to the above-mentioned method of setting two fingerprint detection units, that is, the method of splicing two light-sensitive areas, the three parameters W, G, and H are reasonably set to meet the requirements of the effective area of the fingerprint detection area, and low Low-cost under-screen optical fingerprint recognition solution. According to this splicing method, the data output from the regions of the two fingerprint detection units can be spliced together through the digital image processing algorithm to perform fingerprint recognition.

Optionally, as a second embodiment, the fingerprint detection device may include four fingerprint detection units.

Optionally, the four fingerprint detection units can be arranged in various ways. For example, four fingerprint detection units may be arranged in a row or a column, or four fingerprint detection units may be arranged in a 2*2 matrix.

Fig. 13 shows a schematic diagram of the arrangement of four fingerprint detection units according to the embodiment of the present application. As shown in FIG. 13 , it is assumed here that four rectangular fingerprint detection units are arranged in a 2*2 matrix, wherein each fingerprint detection unit may be the fingerprint detection unit 20 shown in FIGS. 3 to 8 above.

Specifically, as shown in Figure 13, the length of each fingerprint detection unit is denoted as H, the width of each fingerprint detection unit is denoted as W, and the horizontal distance between two adjacent fingerprint detection units in the horizontal direction is Denoted as G1, the vertical distance between two adjacent fingerprint detection units in the vertical direction is denoted as G2. The rectangular boxes around the four fingerprint detection units in FIG. 13 can represent the effective range of the fingerprint detection area, which is larger than the total area of the fingerprint detection units. Optionally, the actual area of the fingerprint detection area may be larger than its effective range, and the effective range represents the minimum area that can be used for fingerprint identification. For example, other functional areas may also be set in the fingerprint detection area. Not limited to this.

It should be understood that, as shown in Figure 13, according to the size of the field of view of each fingerprint detection unit on the upper surface of the display screen, in the case of setting four fingerprint detection units, by reasonably setting W, H, G1 and G2 The size can make it meet the requirements of the effective area size of the fingerprint detection area. For example, it can be determined based on the distance of the field of view of each fingerprint detection unit on the upper surface of the display screen relative to the edge of each fingerprint detection unit and the minimum effective area of the fingerprint detection area in the display screen. The size and distance of each fingerprint detection unit to meet the requirements of the fingerprint detection area.

Specifically, the size parameter includes: the field of view range of each fingerprint detection unit on the upper surface of the display screen is at least a first value X (that is, ΔL is greater than or equal to the first value X) at the edge of each fingerprint detection unit. value X), and the length of the fingerprint detection area is greater than or equal to the second value Y, and the width of the fingerprint detection area is greater than or equal to the third value Z, then referring to Figure 13, the following parameters can be set correspondingly: the The length H of each fingerprint detection unit is greater than or equal to 0.5Y-2X, the width W of each fingerprint detection unit is greater than or equal to 0.5Z-2X, and the horizontal distance G1 between two adjacent fingerprint detection units in the horizontal direction is less than or equal to 2X, and the vertical distance G2 between two adjacent fingerprint detection units in the vertical direction is less than or equal to 2X.

For example, assume that the size parameters of the embodiment of the present application include: the range of the field of view of each fingerprint detection unit on the upper surface of the display screen is at least 0.75mm (that is, ΔL is greater than or equal to 0.75mm) ), and the area of the fingerprint detection area is greater than or equal to 6mm*6mm, then with reference to Figure 13, the following parameters can be set correspondingly: the length H of each fingerprint detection unit can be set to be greater than or equal to 1.5mm, each fingerprint detection unit The width W of W can be set to be greater than or equal to 1.5mm, the horizontal distance G1 between two adjacent fingerprint detection units in the horizontal direction can be set to be less than or equal to 1.5mm, and the two fingerprint detection units adjacent to the vertical direction The vertical distance G2 between them can be set to be less than or equal to 1.5 mm.

For example, according to the above size parameters, the length H of each fingerprint detection unit can be set to 2.3mm, the width W of each fingerprint detection unit can be set to 2.3mm, and the distance between two adjacent fingerprint detection units in the horizontal direction The horizontal distance G1 is set to 1.2mm, and the vertical distance G2 between two adjacent fingerprint detection units in the vertical direction is set to 1.2mm, then the effective area of the four-electron beam eye splicing scheme is (2.3×2+1.2+ 1.5) ² =7.3×7.3 (mm ² ).

For another example, assume that the size parameters of the embodiment of the present application include: the range of field of view of each fingerprint detection unit on the upper surface of the display screen is at least 0.6mm outside the edge of each fingerprint detection unit (that is, ΔL is greater than or equal to 0.6mm ), and the area of the fingerprint detection area is greater than or equal to 6mm*6mm, then with reference to Figure 13, the following parameters can be set correspondingly: the length H of each fingerprint detection unit can be set to be greater than or equal to 1.8mm, each fingerprint detection unit The width W can be set to be greater than or equal to 1.8mm, the horizontal distance G1 between two adjacent fingerprint detection units in the horizontal direction can be set to be less than or equal to 1.2mm, and the two fingerprint detection units adjacent to the vertical direction The vertical distance G2 between them can be set to be less than or equal to 1.2 mm.

Fig. 14 shows the schematic diagram of the set size of four fingerprint detection units in the embodiment of the present application. When the edge of the unit is expanded to 0.6mm, the length H of each fingerprint detection unit can be set to 2.6mm, the width W of each fingerprint detection unit can be set to 2.6mm, and two adjacent fingerprints in the horizontal direction The horizontal distance G1 between the detection units is set to 1 mm, and the vertical distance G2 between two adjacent fingerprint detection units in the vertical direction is set to 1 mm, then correspondingly, the effective area of the fingerprint detection area is (2.6× 2+1+1.2) ² =7.4×7.4 (mm ² ), meeting the requirement that the area of the fingerprint detection area is greater than or equal to 6mm*6mm.

For another example, assume that the size parameters of the embodiment of the present application include: the range of field of view of each fingerprint detection unit on the upper surface of the display screen is at least 0.3mm outside the edge of each fingerprint detection unit (that is, ΔL is greater than or equal to 0.3mm ), and the area of the fingerprint detection area is greater than or equal to 6mm*6mm, then with reference to Figure 13, the following parameters can be set correspondingly: the length H of each fingerprint detection unit can be set to be greater than or equal to 2.4mm, each fingerprint detection unit The width W can be set to be greater than or equal to 2.4mm, the horizontal distance G1 between two adjacent fingerprint detection units in the horizontal direction can be set to be less than or equal to 0.6mm, and the two fingerprint detection units adjacent to the vertical direction The vertical distance G2 between them can be set to be less than or equal to 0.6mm.

It should be understood that, similar to when two fingerprint detection units are set, no matter how many fingerprint detection units are set, the distance of the field of view of each fingerprint detection unit on the upper surface of the display screen is expanded relative to the edge of each fingerprint detection unit ΔL can be determined by the parameters h ₁ , h ₂ , θ ₁ and θ ₂ according to formula (1), and the range of ΔL can be set according to the actual application, for example, the above-mentioned 0.6mm or 0.75mm can be set, Alternatively, it may be set to a larger or smaller value. For example, ΔL is generally set to be greater than or equal to 0.3 mm. For the sake of brevity, details are not repeated here.

According to the above two embodiments, the fingerprint detection device can include two or four fingerprint detection units by splicing, on this basis, other numbers of fingerprint detection units can also be set, for example, more than 4 can also be set The fingerprint detection unit, the embodiment of the present application is not limited thereto.

In addition, the splicing scheme of the fingerprint detection unit can be implemented on a single CMOS imaging chip, or it can be realized by splicing multiple small-area CMOS imaging chips with an optical path structure of the fingerprint detection unit. Both of them can realize low-cost, large-scale Field of view, ultra-thin under-display optical fingerprint.

In the embodiment of the present application, the data output by each fingerprint detection unit may be processed by a digital image reconstruction algorithm. Specifically, the image data in the same direction of the sensing area of each fingerprint detection unit is shifted by specific pixels to obtain the clearest image in this area; images of the same corresponding area of different fingerprint detection units can be spliced by moving specific pixels , to obtain the clearest image. In the stitching process, interpolation can be used to make up for the problem of different sampling of image data in non-overlapping areas. Compared with the single-object telecentric microlens array solution, under the same field of view, the area of multiple fingerprint detection units in the fingerprint identification device of the embodiment of the present application is smaller, the amount of data obtained is less, and the consumption of software resources is lower. Small. In addition, the space between the AA areas of each fingerprint detection unit can be used to lay out the wiring, or can also be used to place the drive circuit and control circuit of the CMOS sensitive unit pixel, which can further reduce the area of the chip.

For the convenience of explanation, the image processing method of an optical sensor pixel array included in a fingerprint detection unit is used as an example for description, and each fingerprint detection unit in the multiple fingerprint detection units included in the fingerprint detection device can perform image processing in the same way .

Specifically, for a fingerprint detection unit, it includes an optical sensing pixel array, the optical sensing pixel array includes a plurality of optical sensing pixels, and the plurality of optical sensing pixels are divided into multiple groups of optical sensing pixels, and the same group of optical sensing pixels is used for The optical signals in the same direction are received, that is, the optical signals received by the same group of optical sensing pixels pass through the same light guide channel in the same direction.

The optical sensing pixel array is divided into multiple groups of optical sensing pixels, and the multiple groups of optical sensing pixels are used to receive light signals from multiple directions to obtain multiple images, and the multiple images are used to detect fingerprint information of fingers. For example, each fingerprint detection unit may directly output the multiple images, or may reconstruct an image from the multiple images, and the reconstructed image is used for fingerprint recognition.

Optionally, a group of optical sensing pixels in the plurality of groups of optical sensing pixels is used to receive an optical signal in one direction in the plurality of directions to obtain an image in the plurality of images. For example, as shown in Figure 5, assuming that the optical sensing pixel array in the fingerprint detection unit can receive light from four directions in total, that is, the fingerprint detection unit includes light guide channels in four directions, then the optical sensing pixel array can be divided into four directions. It is four groups of optical sensing pixels, wherein, the first group of optical sensing pixels is used to receive light signals in the first direction, for example, the first group of optical sensing pixels may include the optical sensing pixels included in the upper left corner of FIG. A group of electrical signals, the first group of electrical signals is used to form the first image; and so on, the second group of optical sensing pixels is used to receive light signals in the second direction, for example, the second group of optical sensing pixels can include the The optical sensing pixels included in the upper right corner are converted into a second group of electrical signals, which are used to form a second image; the third group of optical sensing pixels is used to receive light signals in a third direction, such as the third The group of optical sensing pixels may include the optical sensing pixels included in the lower left corner of FIG. Directional optical signals, for example, the fourth group of optical sensing pixels may include the optical sensing pixels included in the lower right corner of FIG. 5 , and converted into a fourth group of electrical signals, which are used to form a fourth image.

Optionally, the number of pixels in each group of the multiple groups of optical sensing pixels can be equal or unequal; if the number of the multiple groups of optical sensing pixels is equal, then the same arrangement can be adopted. For example, as shown in Figure 5, assuming that the bottom of each microlens is like the second microlens 212, four optical sensing pixels are correspondingly distributed, so when the optical sensing pixel array is grouped, each microlens can be placed on the upper left The optical sensing pixels on each side are divided into the same group, and the optical signals received by the optical sensing pixels in the same group are in the same direction; similarly, they can be divided into four groups, and the number of optical sensing pixels included in the four groups of optical sensing pixels is the same. are the same, and the arrangement is also the same, and they are all located at the position corresponding to the upper left corner of the microlens.

It should be understood that when the optical sensing pixel array is divided into multiple groups of optical sensing pixels, each optical sensing pixel in each group of optical sensing pixels may correspond to a pixel in an image, that is to say, each optical sensing pixel in the optical sensing pixel array Each optical sensor pixel corresponds to only one pixel point, so the corresponding image is relatively clear, and the relative calculation amount is relatively large.

In consideration of reducing the amount of calculation, optionally, for any group of optical sensing pixels in the multiple groups of optical sensing pixels, one pixel point may also be generated by a plurality of optical sensing pixels. For example, assuming that the number of optical sensing pixels included in multiple groups of optical sensing pixels is the same, the preset number of optical sensing pixels in a group of optical sensing pixels can be correspondingly output as one pixel, which can greatly reduce the number of optical sensing pixels. Calculations.

Among them, the multiple optical sensing pixels in the same group of optical sensing pixels that output the same pixel point may not be adjacent to each other, that is to say, for any continuous multiple optical sensing pixels used to output the same pixel point In terms of sensing pixels, other optical sensing pixels may exist between any two optical sensing pixels in the continuous plurality of optical sensing pixels, but the optical signals received by the existing optical sensing pixels are different from those of the continuous plurality of optical sensing pixels. The direction of the light signal received by each optical sensing pixel is different, that is to say, the following optical sensing pixel cannot exist between any two optical sensing pixels in the continuous plurality of optical sensing pixels: the light received by the optical sensing pixel The direction of the signal is the same as the direction of the light signals received by the continuous plurality of optical sensing pixels.

For example, taking FIG. 5 as an example, assuming that each microlens is the same as the second microlens 212 and corresponds to four optical sensing pixels, the optical sensing pixels in the upper left corner of each microlens belong to the same group, and for this group of optical sensing pixels In terms of sensing pixels, one or more optical sensing pixels continuous with the third optical sensing pixel 243 may include: one or more micro lenses adjacent to the second micro lens 212 (such as shown in FIG. 3 In the first microlens 211 and the third microlens 213), the optical sensing pixel corresponding to the upper left corner of each microlens; meanwhile, one or more optical sensing pixels continuous with the third optical sensing pixel 243 will not include: The optical sensing pixels corresponding to the microlenses that are not adjacent to the second microlens 212 , for example, do not include the optical sensing pixels corresponding to any microlens that is separated from the second microlens 212 by other microlenses. Moreover, the third optical sensing pixel 243 and one or more other continuous optical sensing pixels can be used to jointly output a pixel point.

It should be understood that, according to the manner described above, each fingerprint detection unit can output one or more images, for example, assuming that each of the multiple fingerprint detection units finally outputs a fingerprint image, the multiple images can be combined, for fingerprint detection. Or, if each fingerprint detection unit in a plurality of fingerprint detection units outputs a plurality of images, for example, the plurality of images correspond to optical signals in multiple directions, the fingerprints with the same optical signal in all the images output by the plurality of fingerprint detection units can be The images are merged, for example, the image data in the same direction of the sensing area of each fingerprint detection unit is shifted by specific pixels to obtain the clearest image in this area; the images of the same corresponding area of different fingerprint detection units can be specified by moving Pixels stitch images together to get the clearest images.

In addition, the fingerprint detection device of the embodiment of the present application can also be used for 2D and 3D identification of true and false fingerprints. Since each fingerprint detection unit can receive images in multiple directions, for example, it can receive images in four directions. In the case where the valleys and ridges of the fingerprint are pressed against the upper surface of the OLED screen, when light is received in an oblique direction, due to the characteristics of Brewster's angle, the place where the upper surface of the OLED screen is located in the valley reflects linearly polarized light and penetrates into the mobile phone. When the reflected linearly polarized light is parallel to the linear polarizer of the mobile phone, the light intensity received by the lower sensor is the largest; when the reflected linearly polarized light is perpendicular to the direction of the linear polarizer of the mobile phone screen, the light received by the lower sensor is the weakest. That is to say, when the 3D fingerprint is pressed on the upper surface of the OLED screen, the original image data of the electron beam eye and the linear polarizer of the mobile phone screen are different in different directions, but the difference is not obvious for the 2D fingerprint. Therefore, 2D fake fingerprints and 3D fingerprints can be distinguished to a certain extent by distinguishing the raw data differences of different directions of light.

Therefore, the fingerprint detection device of the embodiment of the present application includes a plurality of fingerprint detection units. By splicing the plurality of fingerprint detection units reasonably, a large field of view and oblique light reception can be realized, thereby reducing the actual chip area and chip size. It reduces the cost, reduces the consumption of software resources, and can also improve the imaging effect of dry hand fingerprints.

The embodiment of the present application also provides an electronic device, which may include a display screen and the 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 the under-screen optical Fingerprint detection.

The electronic device can be any electronic device with a display screen.

The display screen may be the display screen described above, such as an OLED display screen or other display screens, and related descriptions of the display screens may refer to the description of the display screens in the above description, and for the sake of brevity, details are not repeated here.

The electronic device may also include at least one processor, and the at least one processor is used for processing data output by multiple fingerprint detection units. For example, the electronic device can respectively receive the image data output by each fingerprint detection unit through a processor, for example, can receive the data of each fingerprint detection unit through a serial peripheral interface (Serial Peripheral Interface, SPI), and send the Data from multiple fingerprint detection units are processed. Alternatively, the electronic device can also receive the image data output by each fingerprint detection unit through the SPI interface of multiple processors, and after each processor processes them separately, one of the processors can perform combined processing. Examples are not limited to this.

It should be understood that the specific examples in the embodiments of the present application are only for helping those skilled in the art to better understand the embodiments of the present application, rather than limiting 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 of "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 otherwise.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present application.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

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

The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

If the functions described above are realized in the form of software function units and sold or used as independent products, they 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 the 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 Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (read-only memory, ROM), random access memory (random access memory, RAM), magnetic disk or optical disk and other various media that can store program codes. .

The above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto. Anyone familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the application. Should be covered within the protection scope of this application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims (37)

1. A fingerprint detection device, characterized in that, it is applicable to the bottom of the display screen to realize optical fingerprint detection under the screen, the display screen includes a fingerprint detection area, and the fingerprint detection area is used for finger touch to perform fingerprint detection, so The fingerprint detection device includes: A plurality of fingerprint detection units, the minimum size of each fingerprint detection unit in the plurality of fingerprint detection units and the maximum distance between two adjacent fingerprint detection units are set according to size parameters, and the size parameters include the following parameters At least one of: the field of view range of each fingerprint detection unit, the area of the fingerprint detection area, the thickness of the display screen, and the upper surface of the optical path of each fingerprint detection unit to the lower surface of the display screen distance; Wherein, the effective range of the fingerprint detection area is greater than or equal to the minimum value of the area of the fingerprint detection area, and the effective range is the minimum area for fingerprint identification; Wherein, each fingerprint detection unit includes: A microlens array, configured to be arranged under the display screen, and includes a plurality of microlenses; At least one light blocking layer is arranged under the microlens array, and is formed with a plurality of light guide channels corresponding to each microlens in the plurality of microlenses, and a plurality of light guide channels corresponding to each microlens The angle between each light guide channel in the light channel and the optical axis of each microlens is less than 90°; The optical sensing pixel array is arranged under the at least one light-blocking layer and includes a plurality of optical sensing pixels, and one is arranged under each of the plurality of light guiding channels corresponding to each microlens. The optical sensing pixel, the one optical sensing pixel is used to receive the optical signal converged by the microlens and transmitted through the corresponding light guide channel, and the optical signal is used to detect the fingerprint information of the finger. 2. The fingerprint detection device according to claim 1, wherein the sizes of the plurality of fingerprint detection units are the same. 3. The fingerprint detection device according to claim 2, characterized in that, among the plurality of fingerprint detection units, a plurality of fingerprint detection units located in the same row are equally spaced apart; and/or, Among the plurality of fingerprint detection units, the distances between the plurality of fingerprint detection units located in the same column are equal. 4. The fingerprint detection device according to claim 1, wherein the number of the plurality of fingerprint detection units is two. 5. The fingerprint detection device according to claim 4, wherein two fingerprint detection units are arranged side by side. 6. The fingerprint detection device according to claim 5, wherein the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is In the case that edge expansion is at least the first value X, and the length of the fingerprint detection area is greater than or equal to the second value Y, and the width of the fingerprint detection area is greater than or equal to the third value Z, each fingerprint detection The length of the unit is greater than or equal to Y-2X, the width of each fingerprint detection unit is greater than or equal to 0.5Z-2X, and the horizontal distance between the two fingerprint detection units is less than or equal to 2X. 7. The fingerprint detection device according to claim 1, wherein the number of the plurality of fingerprint detection units is four. 8. The fingerprint detection device according to claim 7, wherein the four fingerprint detection units are arranged in a 2*2 matrix. 9. The fingerprint detection device according to claim 8, wherein the size parameters include: the field of view range of each fingerprint detection unit on the upper surface of the display screen is In the case that edge expansion is at least the first value X, and the length of the fingerprint detection area is greater than or equal to the second value Y, and the width of the fingerprint detection area is greater than or equal to the third value Z, each fingerprint detection The length of the unit is greater than or equal to 0.5Y-2X, the width of each fingerprint detection unit is greater than or equal to 0.5Z-2X, the horizontal distance between two adjacent fingerprint detection units in the horizontal direction is less than or equal to 2X, and the vertical distance The vertical distance between two adjacent fingerprint detection units in the vertical direction is less than or equal to 2X. 10. The fingerprint detection device according to any one of claims 1 to 9, characterized in that, The bottoms of the plurality of light guide channels corresponding to each microlens respectively extend below the adjacent plurality of microlenses; or, The bottoms of the plurality of light guide channels corresponding to each microlens are located below the same microlens. 11. The fingerprint detection device according to any one of claims 1 to 9, wherein the plurality of light guide channels corresponding to each microlens are symmetrically distributed along the optical axis of the same microlens. 12. The fingerprint detection device according to any one of claims 1 to 9, characterized in that, each of the plurality of light guide channels corresponding to each microlens and the first plane form a preset angle, so that the plurality of optical sensing pixels arranged under each microlens are respectively used to receive the optical signals converged by the microlens and transmitted through the corresponding light guide channel, wherein the first plane is the same as the first plane A plane parallel to the display screen described above. 13. The fingerprint detection device according to claim 12, wherein the range of the preset included angle is 15 degrees to 60 degrees. 14. The fingerprint detection device according to claim 13, wherein the projections of the plurality of light guide channels corresponding to each microlens on the first plane are within the first plane relative to the optical axis of the same microlens. The projection center of the plane is distributed symmetrically. 15. The fingerprint detection device according to claim 14, wherein the optical sensing pixel array includes multiple groups of optical sensing pixels, and the light signals received by the same group of optical sensing pixels in the multiple groups of optical sensing pixels pass through The directions of the light guide channels are the same, and the multiple groups of optical sensing pixels are used to receive light signals from multiple directions to obtain multiple images, and the multiple images are used to detect fingerprint information of the finger. 16. The fingerprint detection device according to claim 15, wherein a group of optical sensing pixels in the plurality of groups of optical sensing pixels is used to receive an optical signal from one of the plurality of directions to obtain the plurality of fingerprints An image in an image. 17. The fingerprint detection device according to claim 16, characterized in that, the number of pixels in each group of pixels in the plurality of groups of pixels is equal, and the arrangement is the same. 18 . The fingerprint detection device according to claim 16 , wherein one optical sensing pixel in a group of optical sensing pixels in the plurality of groups of optical sensing pixels corresponds to a pixel point in an image. 19 . The fingerprint detection device according to claim 16 , wherein a plurality of continuous optical sensing pixels in a group of optical sensing pixels among the plurality of groups of optical sensing pixels correspond to one pixel point in an image. 20. The fingerprint detection device according to any one of claims 1 to 9, characterized in that the distribution of a plurality of optical sensing pixels under each microlens is rectangular or rhombus. 21. The fingerprint detection device according to any one of claims 1 to 9, wherein the at least one light-blocking layer is a plurality of light-blocking layers, and each microlens is arranged in a different light-blocking layer corresponding to at least one opening to form a plurality of light guide channels corresponding to each microlens. 22. The fingerprint detection device according to claim 21, wherein the number of openings corresponding to the same microlens in different light blocking layers increases sequentially from top to bottom. 23. The fingerprint detection device according to claim 21, characterized in that the apertures of the openings in different light-blocking layers corresponding to the same microlens decrease sequentially from top to bottom. 24. The fingerprint detection device according to claim 21, wherein a plurality of openings corresponding to each of the microlenses are provided in the bottom light-shielding layer among the plurality of light-shielding layers, and each of the light-shielding layers A plurality of light guide channels corresponding to the microlens respectively pass through a plurality of openings corresponding to the same microlens in the bottom light blocking layer. 25. The fingerprint detection device according to claim 21, wherein the top light-shielding layer among the plurality of light-shielding layers is provided with an opening on the optical axis of each microlens, and each of the light-shielding layers The plurality of light guiding channels corresponding to the microlens all pass through the openings corresponding to the same microlens in the top light blocking layer. 26. The fingerprint detection device according to claim 21, wherein the non-bottom light-blocking layer in the plurality of light-blocking layers is at the back focus of two adjacent microlenses in the plurality of microlenses. An opening is provided at the middle position, and the two light guide channels corresponding to the two adjacent microlenses pass through the corresponding openings of the two adjacent microlenses in the non-bottom light blocking layer, so as to The bottoms of the plurality of light guide channels corresponding to each microlens respectively extend below the adjacent plurality of microlenses. 27. The fingerprint detection device according to any one of claims 1 to 9, wherein the at least one light-blocking layer only includes one light-blocking layer, and the plurality of light-guiding channels are the one light-blocking layer A plurality of inclined vias corresponding to the same microlens in the layer. 28. The fingerprint detection device according to claim 27, wherein the thickness of said one light-shielding layer is greater than a preset threshold, so that a plurality of optical sensing pixels arranged under each microlens are respectively used to receive The light signal is collected by the microlens and transmitted through the corresponding light guide channel. 29. The fingerprint detection device according to any one of claims 1 to 9, wherein each fingerprint detection unit further comprises: The transparent medium layer is set in at least one of the following positions: Between the microlens array and the at least one light blocking layer, between said at least one light blocking layer, and The at least one light blocking layer and the optical sensing pixel array. 30. The fingerprint detection device according to any one of claims 1 to 9, characterized in that, the at least one light-blocking layer and the microlens array are integrated, or the at least one light-blocking layer and the The optical sensing pixel array is integrated. 31. The fingerprint detection device according to any one of claims 1 to 9, wherein each microlens satisfies at least one of the following conditions: The projection of the light-gathering surface of the microlens on a plane perpendicular to its optical axis is rectangular or circular; The light-gathering surface of the microlens is an aspheric surface; The curvature in each direction of the light-gathering surface of the microlens is the same; The microlens includes at least one lens; and The focal length range of the microlens is 10um-2mm. 32. The fingerprint detection device according to any one of claims 1 to 9, wherein the microlens array satisfies at least one of the following conditions: The microlens array is arranged in a polygon; and The duty ratio of the microlens array ranges from 100% to 50%. 33. The fingerprint detection device according to any one of claims 1 to 9, wherein the period of the microlens array is not equal to the period of the optical sensing pixel array, and the period of the microlens array is a rational multiple of the period of the optical sensing pixel array. 34. The fingerprint detection device according to any one of claims 1 to 9, wherein the distance between the fingerprint detection device and the display screen is 20um-3000um. 35. The fingerprint detection device according to any one of claims 1 to 9, wherein each fingerprint detection unit further comprises: Filter layer, set at least one of the following positions: above the microlens array, and between the microlens array and the optical sensing pixel array. 36. An electronic device, comprising: display screen; and A fingerprint detection device according to any one of claims 1-35. 37. The electronic device according to claim 36, wherein the display screen comprises a fingerprint detection area, and the fingerprint detection area is used to provide a touch interface for fingers.