TWM605463U - Under-screen optical fingerprint recognition component and electronic equipment - Google Patents

Abstract

This creation is about under-screen optical fingerprint recognition components and electronic equipment, under-screen optical fingerprint recognition Other components include cover plates, light-emitting components, and optical fingerprint recognition modules. The cover plate is processed with a reflective surface so that the light emitted by the light-emitting element can be totally reflected in the cover plate after entering the cover plate. When a finger enters the fingerprint recognition area of the cover plate, the light emitted by the light emitting element into the cover plate is reflected by the fingerprint of the finger, passes through the cover plate and the liquid crystal display module, and is captured by the optical fingerprint recognition module to complete fingerprint image collection. In this creation, the light entering the cover plate of the light-emitting element is totally reflected in the cover plate by setting the reflective surface, which greatly reduces the light loss and ensures that the optical fingerprint recognition module can capture clear fingerprint images; in addition, the light-emitting element is set in Within the coverage of the cover, the optical fingerprint element under the screen will not affect the LCD screen, and even the structural design of the LCD screen is equipped, which simplifies the structure and reduces the cost.

Description

Under-screen optical fingerprint recognition components and electronic equipment

This creation is about biometric detection components and their application equipment, especially about fingerprint recognition components and electronic devices using the fingerprint recognition components.

The optical fingerprint recognition module under the conventional technology screen is mostly used in Organic Light-Emitting Diode (OLED) display screen. It is assumed that the method used for liquid crystal display (LCD) is the first Means, as shown in FIG. 2, the LCD screen includes an LCD module 961 and a backlight module 962, a glass cover 93 is covered on the LCD module 961, and a light source 941 and an optical fingerprint recognition module 95 are arranged under the backlight module 962. As shown by the arrow, the fingerprint of the finger 99 on the cover 93 is illuminated through the light source 941, and the reflected light information is collected through the optical fingerprint recognition module 95 to obtain a fingerprint image. Due to the relatively complex structure of the LCD screen, the light path emitted by the light source 941 needs to pass through the LCD module 961 and the backlight module 962 twice. The light loss increases exponentially with the number of passes through the LCD screen. The light loss is serious. Optical fingerprint recognition The module 95 cannot capture clear images, which makes this method unusable for mass production.

In order to reduce the number of times the light path passes through the LCD screen, a second method as shown in Figure 3 is proposed. The light source 942 is attached under the cover 93, and the finger 99 is illuminated through the light source 942. The optical fingerprint recognition module 95 collects the reflected light from the finger 99. Optical information to obtain fingerprint images. In this method, the light source 942 and the cover 93 have a complicated structure, low yield, and high cost; the light emitted by the light source 942 enters the cover 93 and is mostly emitted out of the cover 93 and lost in the air. The light in the cover 93 passes through the fingers. 99 reflects through LCD module 961 and backlight module 962 When it reaches the optical fingerprint recognition module 95, the light emitted by the light source 942 has been lost, and a valid fingerprint image cannot be obtained, so that the method cannot be used for mass production.

In order to reduce the light loss in the cover plate 93, a third method as shown in Fig. 4 is proposed. The light source 943 is arranged on the periphery of the cover plate 93 so that the light emitted by the light source 943 can directly illuminate the finger 99 in the fingerprint recognition area and pass through the finger. The light information reflected by 99 passes through the LCD module 961 and the backlight module 962 to the optical fingerprint recognition module 95 to obtain a fingerprint image. Although this method can reduce part of the light loss, the demand for display screens in the prior art has a trend toward reduced bezels and no bezels. The structure of the device using the display screen does not allow the light source 943 to be installed around the cover 93, or it needs to be used. The complicated structure design realizes the setting of the light source 943, and the cost is high, resulting in the method having no market prospects and cannot be used for mass production.

In summary, for LCD screens with relatively complex structures, the optical fingerprint recognition module under the conventional technology screen has not yet been able to achieve mass production. At the same time, the application of optical fingerprint recognition modules to LCD screens is also affected by the current equipment equipped with LCD screens. The structural limitation prevents the formation of mass production means.

The technical problem to be solved in this creation is to avoid the shortcomings of the conventional technology, and to propose an under-screen optical fingerprint identification device for LCD screens that can reduce light loss and has a simple structure that can be mass-produced.

The solution to the technical problems mentioned in this creation can be achieved by using the following technical means:

Design and manufacture an under-screen optical fingerprint identification element for use in liquid crystal display modules. The under-screen optical fingerprint identification element includes a cover plate made of light-transmitting material covering the liquid crystal display module, and a luminous under the cover plate Components, and an optical fingerprint recognition module set under the liquid crystal display module. The surface of the cover plate has a fingerprint recognition area for fingers to press, and the optical fingerprint recognition module is arranged on the fingerprint Just below the recognition area. The cover plate is processed with a reflective surface, so that the light emitted by the light emitting element can be reflected by the reflective surface after entering the cover plate, and the reflected light is totally reflected in the cover plate. When the finger enters the fingerprint recognition area of the cover plate, the totally reflected light is reflected by the fingerprint of the finger, passes through the cover plate and the liquid crystal display module, and is photographed by the optical fingerprint recognition module to complete the fingerprint image collection.

To simplify the structure, the reflective surface is processed on one end of the cover plate to become the end surface of the cover plate.

Specifically, the reflective surface is formed by obliquely cutting the top surface of the cover plate in the direction of the bottom surface, and the included angle formed by the reflective surface and the bottom surface of the cover plate is an acute angle.

To enhance the reflection effect, a reflective film is provided on the reflective surface.

Specifically, the reflecting surface is any one of a flat surface, a circular arc surface, an elliptical arc surface, a curved surface, a spherical surface, an aspheric surface, and a free-form surface, or a surface formed by combining two or more of them.

When the media on both sides of the cover plate are different, the incident angle of the first reflected light is neither smaller than the critical angle of the inner top surface of the cover plate, nor smaller than the critical angle of the inner bottom surface of the cover plate.

Specifically, the optical fingerprint recognition module includes a lens for taking fingerprint images.

In order to improve the light characteristics, the light emitting element further includes a light conversion member capable of changing the light path and/or capable of enhancing the light intensity. The light conversion member includes at least one of a lens, a prism, a condenser lens, and a Fresnel lens.

Specifically, the light-emitting element is an infrared light-emitting diode.

The solution to the technical problems mentioned in this creation can also be achieved by using the following technical means:

Design and manufacture an electronic device that includes a liquid crystal display module and an under-screen optical fingerprint identification element. The under-screen optical fingerprint identification element includes a cover plate made of light-transmitting material that covers the liquid crystal display module and is arranged under the cover plate The light-emitting element, and the optical fingerprint recognition module set under the liquid crystal display module. The surface of the cover has a fingerprint recognition area for fingers to press, and the optical fingerprint recognition module is arranged directly below the fingerprint recognition area. The cover plate is processed with a reflective surface, so that the light emitted by the light emitting element can be reflected by the reflective surface after entering the cover plate, and the reflected light is totally reflected in the cover plate.

Compared with the conventional technology, the technical effects of this creation "Under the screen optical fingerprint recognition components and electronic equipment" are:

In this creation, the light entering the cover plate of the light-emitting element is totally reflected in the cover plate by setting the reflective surface, which greatly reduces the light loss and ensures that the optical fingerprint recognition module can capture clear fingerprint images; in addition, the light-emitting element is set in Within the coverage of the cover, the optical fingerprint element under the screen will not affect the LCD screen, and even the structural design of the LCD screen is equipped, which simplifies the structure and reduces the cost.

1: reflective film

2: reflective surface

3: cover

4: Light-emitting element

5: Optical fingerprint recognition module

6: Liquid crystal display module

7: fingers

61: LCD monitor

62: Backlight module

71: Fingerprint

93: cover

95: Optical fingerprint recognition module

99: finger

941: light source

942: light source

943: Light Source

961: LCD module

962: Backlight module

FL: reflected light

OP: Normal

θ: incident angle

Figure 1 is a schematic cross-sectional view of a preferred embodiment of the present creation; Figure 2 is a schematic cross-sectional view of the first means of the prior art; Figure 3 is a schematic cross-sectional view of the second means of the prior art; Figure 4 is the third section of the prior art Schematic cross-section.

The following is a further detailed description with reference to the preferred embodiments shown in the drawings.

The preferred embodiment of the present invention proposes an under-screen optical fingerprint identification device for the liquid crystal display module 6. As shown in Figure 1, the under-screen optical fingerprint recognition element includes a liquid crystal display module 6, a cover 3 made of light-transmitting material, a light-emitting element 4 arranged under the cover 3, and a liquid crystal display module. Optical fingerprint recognition module 5 under group 6. The surface of the cover plate 3 has a fingerprint recognition area for fingers to press, and the optical fingerprint recognition module is arranged directly below the fingerprint recognition area. The cover plate 3 is processed with a reflective surface 2, so that the light emitted by the light-emitting element 4 can be reflected by the reflective surface 2 to form a reflected light FL after entering the cover plate 3, as shown by the arrow in FIG. 1, and the reflected light FL is on the cover plate 3. Total reflection occurs. That is, the reflected light FL is incident on the bottom surface of the cover 3 at an incident angle θ not less than the critical angle on the inner surface of the cover 3 (θ is the angle between the reflected light FL and the normal OP of the inner bottom surface of the cover 3), so that The light emitted from the light emitting element 4 into the cover plate 3 is totally reflected in the cover plate 3. When the finger 7 enters the fingerprint recognition area of the cover 3, the total reflection light path of the light emitting element 4 entering the cover 3 is destroyed, and a part of the light is reflected by the finger 7 and enters the optical fingerprint recognition module 5 at the position below the fingerprint recognition area. The optical fingerprint identification module 5 includes a lens for taking fingerprint images. Because the ridge of the fingerprint 71 reflects more light and the valley of the fingerprint 71 reflects less light, the ridge of the fingerprint 71 corresponds to a larger amount of signal, and the valley of the fingerprint 71 corresponds to a smaller amount of signal, so it can be used for signal amplification. Operation, so that the optical fingerprint recognition module 5 obtains a fingerprint image through the waveform change of the detection signal, and then performs fingerprint recognition. The critical angle is the incident angle of the light at which the refraction angle reaches 90 degrees when the light is emitted from the optically dense medium (higher refractive index) to the lighter medium (lower refractive index). Once the critical angle is reached or exceeded , The incident light will only reflect but not refraction.

In this creation, the reflective surface 2 is set to make the light of the light-emitting element 4 incident on the cover 3 form total reflection in the cover 3, which greatly reduces light loss and ensures that the optical fingerprint recognition module 5 can capture clear fingerprint images; in addition, The light-emitting element 4 is arranged within the coverage of the cover 3 so that the optical fingerprint element under the screen will not affect the LCD screen, and even the structural design of the LCD screen is equipped, which simplifies the structure, reduces the cost, and enables the creation of mass production.

In this creation, a plurality of light-emitting elements 4 can also be arranged according to light intensity requirements or other process requirements.

In the preferred embodiment of the invention, as shown in FIG. 1, the reflecting surface 2 is processed on one end of the cover 3 to become the end surface of the cover 3, so that the reflecting surface 2 is realized with a relatively simple structure. Obviously, a reflective surface 2 can also be built into the cover 3 through modern technology.

In the preferred embodiment of the present creation, as shown in Fig. 1, the reflecting surface 2 is formed by obliquely cutting the top surface of the cover plate 3 in the direction of the bottom surface, and the included angle formed by the reflecting surface 2 and the bottom surface of the cover plate 3 is an acute angle.

By designing the angle at which the light emitting element 4 emits light, the material of the reflecting surface 2 and the inclination angle of the reflecting surface 2, the light emitted from the light emitting element 4 into the cover 3 enters the reflecting surface at an angle not less than the critical angle, so that the light emitting element 4 The light incident on the cover plate 3 is reflected on the surface of the reflective surface 2 to form a reflected light FL, and the reflected light FL is totally reflected in the cover plate 3. In this embodiment, as shown in FIG. 1, the reflective surface 2 of the cover 3 is further coated with a reflective film 1. For example, the reflective surface 2 is plated into a mirror surface to achieve the anti-refraction effect. There are many implementations here, not one example.

In the preferred embodiment of the present creation, as shown in Fig. 1, the reflecting surface 2 is a flat surface. According to the light-emitting characteristics of the light-emitting element 4, such as the light-emitting path, light intensity, and some requirements for improving the characteristics of the light entering the cover 3, the reflective surface 2 may also be a circular arc surface, an elliptical arc surface, Any of curved surfaces, spherical surfaces, aspheric surfaces, and free-form surfaces, or a surface formed by combining two or more of them. The structure of various reflective surfaces 2 can at least realize that: a light emitting element 4 is provided under the cover plate 3, and the light emitted from the light emitting element 4 into the cover plate 3 can pass through the reflective surface 2 to achieve total reflection in the cover plate 3. In the preferred embodiment of the invention, as shown in FIG. 1, the light emitted by the light-emitting element 4 vertically enters the bottom surface of the cover 3. In actual use, according to changes in design requirements, the light emitted by the light-emitting element 4 should be able to enter the cover 3 in various directions, and pass through the structural design of the reflective surface 2 to make the reflected light FL meet the requirements.

When the top and bottom surfaces of the cover 3 are in different media, the incident angle of the first reflected light FL is neither less than the critical angle of the inner top surface of the cover 3, nor less than the critical angle of the inner bottom surface of the cover 3 angle.

The preferred embodiment of this creation, as shown in FIG. 1, directly uses the light emitted by the light-emitting element 4 to enter the cover 3. In practical applications, the light-emitting element 4 can also be combined with various light conversion components to achieve the effects of improving the light path and adjusting the light intensity. Therefore, the light-emitting element 4 also includes a light conversion that can change the light path and/or can enhance the light intensity. member. The light conversion component includes at least one of a lens, a prism, a condenser lens and a Fresnel lens, through one of them, or a combination of two or more to achieve the effect of changing the light path, enhancing the light intensity, or even both effect.

In a preferred embodiment of the invention, as shown in FIG. 1, the light-emitting element 4 is an infrared light-emitting diode, that is, an infrared light-emitting diode.

In a preferred embodiment of the invention, as shown in FIG. 1, the liquid crystal display module 6 includes a liquid crystal display 61 and a backlight module 62 arranged under the liquid crystal display 61.

This creation also proposes an electronic device that includes a liquid crystal display module and an under-screen optical fingerprint identification element. The under-screen optical fingerprint identification element includes a cover plate made of light-transmitting material that covers the liquid crystal display module and is set under the cover plate. A light-emitting element, and an optical fingerprint recognition module arranged under the liquid crystal display module; the surface of the cover plate has a fingerprint sensing area for finger pressing, and the optical fingerprint recognition module is arranged directly below the fingerprint recognition area; The cover plate is processed with a reflective surface, so that the light emitted by the light emitting element can be reflected by the reflective surface after entering the cover plate, and the reflected light is totally reflected in the cover plate. When the finger enters the fingerprint recognition area of the cover plate, the totally reflected light is reflected by the fingerprint of the finger, passes through the cover plate and the liquid crystal display module, and is photographed by the optical fingerprint recognition module to complete the fingerprint image collection. The electronic equipment is a mobile communication terminal, a computer, a palmtop computer, a tablet computer, a video/audio playback device or an electronic watch.

The above implementations are only used to illustrate the technical means of this creation, not to limit it. Although this creation has been described in detail with reference to the above preferred implementations, those with ordinary knowledge in the field to which this creation belongs should understand that the technical means of this creation can be modified or modified. No equivalent replacement should deviate from this creative technique The spirit and scope of the technique. Those with ordinary knowledge in the field to which this creation belongs can also make other changes within the spirit of this creation, etc., as long as it does not deviate from the technical effect of this creation. These changes based on the spirit of this creation should all be included in the scope of protection required by this creation.

1: reflective film

2: reflective surface

3: cover

4: Light-emitting element

5: Optical fingerprint recognition module

6: Liquid crystal display module

7: fingers

61: LCD monitor

62: Backlight module

71: Fingerprint

FL: reflected light

OP: Normal

θ: incident angle

Claims (10)

An under-screen optical fingerprint identification element, characterized in that: the under-screen optical fingerprint identification element is used for a liquid crystal display module; the under-screen optical fingerprint identification element includes a cover made of transparent material covering the liquid crystal display module Board, a light-emitting element arranged under the cover, and an optical fingerprint recognition module arranged under the liquid crystal display module; the surface of the cover has a fingerprint recognition area for fingers to press, and the optical fingerprint recognition module is arranged at Directly below the fingerprint recognition area; the cover is processed with a reflective surface, so that the light emitted by the light-emitting element can be reflected by the reflective surface after entering the cover, and the reflected light is totally reflected in the cover; when a finger enters the cover When in the fingerprint recognition area, the totally reflected light is reflected by the fingerprint of the finger, passes through the cover plate and the liquid crystal display module, and is photographed by the optical fingerprint recognition module to complete the fingerprint image collection. The under-screen optical fingerprint identification device according to claim 1, wherein: the reflective surface is processed on one end of the cover plate to become an end surface of the cover plate. The under-screen optical fingerprint identification device according to claim 2, wherein: the reflective surface is formed by obliquely cutting the top surface of the cover plate in the direction of the bottom surface, and the included angle formed by the reflective surface and the bottom surface of the cover plate is an acute angle. The under-screen optical fingerprint identification element according to any one of claims 1 to 3, wherein: a reflective film is provided on the reflective surface. The off-screen optical fingerprint identification device according to claim 1 or 2, wherein: The reflecting surface is any one of a flat surface, a circular arc surface, an elliptical arc surface, a curved surface, a spherical surface, an aspheric surface, and a free curved surface, or a surface formed by combining two or more of them. The under-screen optical fingerprint identification device according to claim 1, wherein: the incident angle of the reflected light is neither smaller than the critical angle of the inner top surface of the cover plate, nor smaller than the critical angle of the inner bottom surface of the cover plate. The under-screen optical fingerprint identification device according to claim 1, wherein: the optical fingerprint identification module includes a lens for taking fingerprint images. The under-screen optical fingerprint recognition element according to claim 7, wherein: the light-emitting element further includes a light conversion device capable of changing the optical path and/or capable of enhancing light intensity; the light conversion member includes a lens, a prism, a condenser, and a Fresnel At least one of the ear lenses. The under-screen optical fingerprint identification element according to claim 1, wherein: the light-emitting element is an infrared light-emitting diode. An electronic device comprising a liquid crystal display module and an under-screen optical fingerprint identification element, characterized in that: the under-screen optical fingerprint identification element includes a cover plate made of light-transmitting material covering the liquid crystal display module, and is arranged on the cover plate The light-emitting element underneath, and the optical fingerprint recognition module arranged under the liquid crystal display module; the surface of the cover plate has a fingerprint recognition area for fingers to press, and the optical fingerprint recognition module is arranged directly below the fingerprint recognition area The cover is processed with a reflective surface, so that the light emitted by the light-emitting element can be reflected by the reflective surface after entering the cover, and the reflected light is totally reflected in the cover.

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