WO2021108968A1

WO2021108968A1 - Under-screen optical fingerprint recognition apparatus and system, and liquid crystal display screen

Info

Publication number: WO2021108968A1
Application number: PCT/CN2019/122489
Authority: WO
Inventors: 杜灿鸿; 蒋方林
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2021-06-10
Also published as: CN111095288A; CN111095288B

Abstract

An under-screen optical fingerprint recognition apparatus and system, and a liquid crystal display screen. The under-screen optical fingerprint recognition apparatus comprises: a detection light source (50) arranged below a backlight module (2), a light path guide structure (6) and an optical fingerprint sensor (7), wherein the detection light source (50) is used for emitting detection light, and the detection light is irradiated on a finger (13) by means of passing through a liquid crystal display screen; the light path guide structure (6) is used for guiding, to the optical fingerprint sensor (7), fingerprint detection light that is reflected by the finger (13), carries fingerprint information and passes through the liquid crystal display screen; the optical fingerprint sensor (7) is used for acquiring fingerprint information of the finger (13) according to the fingerprint detection light; at least one of the detection light and the fingerprint detection light passes through a polarization layer (9); the polarization layer (9) is used for filtering an S wave in the detection light and/or the fingerprint detection light; the polarization layer (9) is located above the under-screen optical fingerprint recognition apparatus; and the polarization direction of the polarization layer (9) is the same as the polarization direction of a first reflection-type polarization film layer (3). The present apparatus has a higher accuracy in fingerprint recognition.

Description

Under-screen optical fingerprint recognition device and system, liquid crystal display

Technical field

This application relates to fingerprint identification technology, in particular to an under-screen optical fingerprint identification device and system, and a liquid crystal display screen.

Background technique

With the development of display technology, identification technology continues to innovate, change and develop, especially fingerprint identification technology in mobile terminals has become the mainstay of identification.

Liquid Crystal Display (LCD) screens have many advantages such as thin body, power saving, and no radiation, and are widely used in electronic products such as TVs, computers, and mobile phones. LCD screens generally need to use a backlight module to illuminate the LCD panel to display images. When the under-screen optical fingerprint recognition technology is applied to a liquid crystal display with reflective polarizing film, the under-screen fingerprint recognition module generally includes: a lens group composed of at least one lens, a fingerprint recognition chip, and a lens set under the liquid crystal display. Light source, etc., the light source emits detection light to irradiate the finger on the surface of the liquid crystal display screen, and the fingerprint detection light reflected on the finger passes through the liquid crystal display and is incident on the lens group. The lens group condenses the fingerprint detection light and illuminates the fingerprint The fingerprint image is formed on the identification chip, and the fingerprint image is collected and recognized by the fingerprint identification chip.

However, in the above fingerprint recognition module, the liquid crystal display includes a reflective polarizing film. Regardless of the detection light emitted by the light source or the fingerprint detection light formed on the finger, when passing through the reflective polarizing film, about 50% reflection will be generated. , And 50% transmission, when the reflected light falls within the field of view of the lens group, it will interfere with the imaging of the fingerprint image, resulting in low fingerprint recognition accuracy.

Summary of the invention

This application provides an under-screen optical fingerprint identification device and system, and a liquid crystal display to solve the problem of low fingerprint identification accuracy in the prior art.

The present application provides an under-screen optical fingerprint identification device, which is suitable for a liquid crystal display with a display module and a backlight module, wherein a first reflective polarizing film layer is arranged between the display module and the backlight module,

The under-screen optical fingerprint recognition device includes: a detection light source, a light path guiding structure and an optical fingerprint sensor arranged under the backlight module; the detection light source is used to emit detection light, the detection light is irradiated to the finger through the liquid crystal display, and the light path guiding structure is used It guides the fingerprint detection light reflected by the finger and carrying fingerprint information through the liquid crystal display to the optical fingerprint sensor; the optical fingerprint sensor is used to obtain the fingerprint information of the finger according to the fingerprint detection light; and the detection light and the fingerprint detection light At least one of the polarizing layer is used to filter out the S wave in the detection light and/or fingerprint detection light. The polarizing layer is located above the optical fingerprint identification device under the screen; the polarization direction of the polarizing layer and the first reflection type The polarization direction of the polarizing film layer is the same.

In the specific embodiment of the present application, the polarizing layer is arranged on the light exit surface of the backlight module, or on the back of the backlight module away from the light exit surface, or arranged in the backlight module.

In the specific embodiment of the present application, the backlight module includes a back plate assembly for fixing the light guide plate, and the polarizing layer is arranged on the back plate assembly.

In the specific embodiment of the present application, the polarizing layer is at least located above the detection light source, so that the detection light passes through the polarizing layer and the liquid crystal display to illuminate the finger;

And the position of the back plate assembly corresponding to the detection light source is provided with a first light through hole, and the polarizing layer above the detection light source at least covers the first light through hole.

In the specific embodiment of the present application, the polarizing layer is located at least above the optical path guiding structure, so that the fingerprint detection light enters the optical path guiding structure through the polarizing layer;

In addition, the position of the back plate assembly corresponding to the light path guiding structure is provided with a second light-passing hole, and the polarizing layer covers at least the second light-passing hole.

In the specific embodiment of the present application, the optical path guiding structure includes an optical lens layer, and the optical lens layer includes one or more aspheric lenses for converging fingerprint detection light onto the optical fingerprint sensor, and the polarizing layer above the optical path guiding structure at least covers The field of view of the optical lens layer.

In the specific embodiment of the present application, a second reflective polarizing film layer and a diffuse reflective layer are also provided,

The second reflective polarizing film layer is arranged between the detection light source and the polarizing layer above the detection light source; the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer.

In the specific embodiment of the present application, the second reflective polarizing film layer is disposed on the back plate assembly, and the second reflective polarizing film layer covers at least the first light-passing hole.

The specific implementation of the application further includes a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the diffuse reflection layer is arranged on the side of the flexible circuit board FPC facing the detection light source.

In the specific embodiment of the present application, the diffuse reflection layer is a white ink layer or a silver powder layer.

In the specific implementation of the present application, the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display screen.

The present application provides an under-screen optical fingerprint identification system, including a liquid crystal display and the above-mentioned under-screen optical fingerprint identification device. The under-screen optical fingerprint identification device is arranged under the liquid crystal display and is used to detect the fingerprint of the finger above the liquid crystal display. Fingerprint information.

In the specific embodiment of the present application, the optical path guiding structure includes an optical lens layer, and the optical lens layer includes one or more aspheric lenses for condensing fingerprint detection light onto the optical fingerprint sensor, and the polarization layer above the optical path guiding structure at least covers The field of view of the optical lens layer.

This application provides a liquid crystal display that supports under-screen fingerprint recognition. The above-mentioned under-screen optical fingerprint recognition device is arranged below the liquid crystal display. The liquid crystal display includes a display module, a backlight module, and a display module and a backlight. The first reflective polarizing film layer between the modules;

It also includes a polarizing layer, the polarizing layer is arranged above the optical fingerprint identification device under the screen, at least one of the detection light and the fingerprint detection light passes through the polarizing layer, and the polarizing layer is used to filter out the detection light and/or fingerprint detection light. S wave;

The polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer.

This application also provides an under-screen optical fingerprint identification device, which is suitable for a liquid crystal display with a display module and a backlight module, wherein a first reflective polarizing film layer is arranged between the display module and the backlight module, and the under-screen The optical fingerprint identification device includes: a detection light source, a light path guiding structure and an optical fingerprint sensor arranged under the backlight module; the detection light source is used to emit detection light, part of the detection light is irradiated to the finger through the second reflective polarizing film layer, and part The detection light is reflected by the second reflective polarizing film layer and then incident on the diffuse reflection layer for diffuse reflection, so that part of the diffusely reflected light passes through the second reflective polarizing film layer and irradiates the finger. The light path guiding structure is used for Guide the fingerprint detection light reflected by the finger, carrying fingerprint information, and passing through the liquid crystal display to the optical fingerprint sensor; the optical fingerprint sensor is used to obtain the fingerprint information of the finger according to the fingerprint detection light;

The second reflective polarizing film layer is arranged above the detection light source, the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer, the polarization direction of the second reflective polarizing film layer and the polarization of the first reflective polarizing film layer The same direction.

In the specific embodiment of the present application, the backlight module includes a back plate assembly for fixing the light guide plate, and the position of the back plate assembly corresponding to the detection light source is provided with a first light through hole, and the second reflective polarizing film layer is provided on the back. On the plate assembly, and the second reflective polarizing film layer at least covers the first through hole.

In the specific embodiment of the present application, a polarization layer is also provided, and at least one of the detection light and the fingerprint detection light passes through the polarization layer. The polarization layer is used to filter out the S wave in the detection light and/or the fingerprint detection light. The layer is located above the optical fingerprint recognition device under the screen;

In the specific embodiment of the present application, the polarizing layer is provided on the back plate assembly, and the second reflective polarizing film layer is located between the polarizing layer and the detection light source, so that the detection light can pass through the second reflective polarizing film layer, the polarizing layer, and the light source. The LCD screen is shining on the finger.

In the specific embodiment of the present application, the side of the back plate assembly facing away from the light guide plate is provided with a fourth fixing groove, and the polarizing layer and the second reflective polarizing film layer are sequentially stacked in the fourth fixing groove.

In the specific embodiment of the present application, the polarizing layer is provided on the back plate assembly, and the polarizing layer is located at least above the optical path guiding structure, so that the fingerprint detection light enters the optical path guiding structure through the polarizing layer;

In the specific embodiment of the present application, the second reflective polarizing film layer at least covers the first light-passing hole.

It also includes a second reflective polarizing film layer and a diffuse reflection layer,

The second reflective polarizing film layer is arranged above the detection light source, and the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer.

In addition, the position of the back plate assembly corresponding to the light path guiding structure is provided with a second light-passing hole, and the polarizing layer at least covers the second light-passing hole.

This application provides an under-screen optical fingerprint identification device and system, and a liquid crystal display. The under-screen optical fingerprint identification device is suitable for a liquid crystal display with a display module and a backlight module. The first reflective polarizing film layer is provided, and the under-screen optical fingerprint recognition device includes: a detection light source, a light path guiding structure and an optical fingerprint sensor arranged under the backlight module; the detection light source is used to emit detection light, and the detection light passes through the liquid crystal display Illuminated to the finger, the light path guiding structure is used to guide the fingerprint detection light reflected by the finger, carrying fingerprint information, and passing through the liquid crystal display to the optical fingerprint sensor; the optical fingerprint sensor is used to obtain the fingerprint of the finger according to the fingerprint detection light Information; and at least one of the detection light and the fingerprint detection light passes through the polarizing layer, the polarizing layer is used to filter out the S wave in the detection light and/or the fingerprint detection light, and the polarizing layer is located above the optical fingerprint recognition device under the screen; polarization; The polarization direction of the layer is the same as the polarization direction of the first reflective polarizing film layer. When light is incident on the first reflective polarizing film layer, the reflected light generated is basically S wave, and the transmitted light generated is basically P wave. This S wave will interfere with the imaging of the fingerprint image, and it will pass under the screen. A polarizing layer is arranged above the optical fingerprint identification device, and the polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer. Therefore, the detection light and/or fingerprint detection light can be first detected by the polarizing layer. The S wave component reflected by the reflective polarizing film is filtered out, which can prevent the reflected light from interfering with the imaging of the fingerprint image, thereby improving the fingerprint recognition accuracy of the fingerprint recognition device.

Description of the drawings

In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description These are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative labor.

Figure 1 is an exploded schematic diagram of natural light;

Figure 2 is a schematic front view of the decomposition of natural light;

3 is a schematic diagram of the working principle of the reflective polarizing brightness enhancement film according to an embodiment of the application;

4 is a schematic structural diagram of an under-screen optical fingerprint identification device provided in Embodiment 1 of this application;

FIG. 5 is a schematic diagram of the working principle of filtering reflected light by the polarizing layer in the under-screen optical fingerprint identification device provided in the first embodiment of the application; FIG.

6 is a schematic diagram of another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application;

FIG. 7 is a schematic diagram of still another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application; FIG.

FIG. 8 is a schematic diagram of still another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application; FIG.

FIG. 9 is a schematic diagram of still another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application; FIG.

FIG. 10 is a schematic diagram of the principle of improving the lighting efficiency in still another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application; FIG.

11 is a schematic structural diagram of an under-screen optical fingerprint identification device provided in Embodiment 2 of this application;

FIG. 12 is a schematic structural diagram of an under-screen optical fingerprint identification device provided in Embodiment 4 of this application; FIG.

FIG. 13 is a schematic diagram of another structure of the under-screen optical fingerprint identification device provided in the fourth embodiment of the application.

Description of reference signs:

1-display module; 2-backlight module; 3-first reflective polarizing film layer; 5-second reflective polarizing film layer; 6-light path guiding structure; 7-optical fingerprint sensor; 9-polarizing layer; 11 -Protection cover; 12-LCD panel; 13-finger; 14-backlight source; 15-middle frame; 16-upper polarizer; 17-lower polarizer; 18-assembly gap; 20-diffusion film; 21-guide Light plate; 22-back plate component; 23-first light hole; 24-second light hole; 25-brightness enhancement film; 26-reflective film; 27-back plate; 28-back plate protective layer; 29-black Adhesive tape; 31-light passing direction of the first reflective polarizing film layer; 32-polarizing direction of the polarizing layer; 33-light passing direction of the second reflective polarizing film layer; 50-detection light source; 51-diffuse reflection layer; 71 -Filter layer; 72-Fixed component; 80-Reflective polarizing brightening film; 81-LED; 100-Under-screen optical fingerprint recognition device; 231-First fixed groove; 232-Flexible circuit board FPC; 241-No. Two fixing grooves; 242-The third fixing groove; 243-The fourth fixing groove; 281-The groove.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

The technical solution of the present application will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

The liquid crystal display in the present application includes a first reflective polarizing film layer, and the first reflective polarizing film layer is a reflective polarizing enhancement film (DBEF). Optionally, the liquid crystal display screen further includes a second reflective polarizing film layer, which is also a reflective polarizing brightening film, for light incident on the first reflective polarizing film layer or the second reflective polarizing film layer, Will produce about 50% reflection and 50% transmission.

Specifically, FIG. 1 is a schematic diagram of the decomposition of natural light, and FIG. 2 is a schematic diagram of a front view of the decomposition of natural light. As shown in Figures 1 and 2, light has polarization characteristics. According to the relationship between the polarization direction and the propagation direction (indicated by the symbol "B" in the figure), it can be divided into P wave and S wave. The polarization direction of P wave is parallel to The plane of light propagation, the polarization direction of the S wave is perpendicular to the plane of light propagation. For natural light, it can be considered to be composed of 50% of the P wave and 50% of the S wave.

FIG. 3 is a schematic diagram of the working principle of the reflective polarizing brightness enhancement film according to an embodiment of the application, in which the dotted arrow indicates the direction of light passing. As shown in Fig. 3, in this application, LED 81 is generally used as the detection light source. The light emitted by LED 81 is natural light. Assuming its intensity is A, the intensity of P wave and S wave are both A/2. The macroscopic characteristic of the reflective polarizing brightness enhancement film 80 is that when the light emitted by the LED 81 is incident on the reflective polarizing brightness enhancement film 80, as shown by the downward arrow in FIG. 3, the reflected light generated is basically S wave ; As shown by the black arrow above the reflective polarizing brightness enhancement film 80, the transmitted light is basically P wave. Therefore, when the natural light emitted by the LED 81 passes through the reflective polarization enhancement film 80, it will produce approximately 50% reflection (S wave component with an intensity of A/2) and 50% transmission (with an intensity of A/2). P wave component).

Because the reflective polarizing brightness enhancement film has the above characteristics, when the liquid crystal display includes the first reflective polarizing film layer, no matter the detection light emitted by the light source or the fingerprint detection light formed on the finger, it will pass through the first reflective polarizing film. When polarizing film layer, it will produce about 50% reflection and 50% projection. Therefore, the fingerprint recognition module of the prior art has the following two problems:

In the first aspect, when the reflected light falls within the field of view of the lens group, it will interfere with the imaging of the fingerprint image, and the fingerprint recognition accuracy rate is not high.

In the second aspect, the intensity of light that produces reflection interference is 50%, and the proportion of transmitted light participating in fingerprint image imaging is relatively small, so that the light source has a low lighting efficiency for the finger.

This application is made to solve the above-mentioned problems.

Example one

FIG. 4 is a schematic structural diagram of an under-screen optical fingerprint identification device provided in Embodiment 1 of the application. As shown in FIG. 4, the under-screen optical fingerprint identification device of this embodiment is suitable for a display module 1 and a backlight module 2 A liquid crystal display screen, wherein a first reflective polarizing film layer 3 is arranged between the display module 1 and the backlight module 2, and the under-screen optical fingerprint recognition device 100 includes: a detection light source 50 and a light path guide arranged under the backlight module 2 Structure 6 and optical fingerprint sensor 7; the detection light source 50 is used to emit detection light, the detection light is irradiated on the finger 13 through the liquid crystal display, and the light path guide structure 6 is used to reflect the finger 13 and carry fingerprint information, and transparent The fingerprint detection light passing through the liquid crystal display is guided to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used to obtain fingerprint information of the finger 13 according to the fingerprint detection light; and at least one of the detection light and the fingerprint detection light passes through the polarizing layer 9, polarized The layer 9 is used to filter out the S wave in the detection light and/or fingerprint detection light. The polarization layer 9 is located above the optical fingerprint identification device under the screen; the polarization direction of the polarization layer 9 and the polarization direction of the first reflective polarizing film layer 3 the same. In the above solution, when light is incident on the first reflective polarizing film layer 3, the reflected light generated is basically S wave, and the transmitted light generated is basically P wave. This S wave will interfere with the imaging of the fingerprint image. , And by setting the polarizing layer 9 above the under-screen optical fingerprint identification device, and the polarization direction of the polarizing layer 9 is the same as the polarization direction of the first reflective polarizing film layer 3, so the detection light and/or In the fingerprint detection light, the S wave component reflected by the first reflective polarizing film may be filtered out, which can prevent the reflected light from interfering with the imaging of the fingerprint image, thereby improving the fingerprint recognition accuracy of the fingerprint recognition device.

In the under-screen optical fingerprint identification device of this embodiment, it is suitable for a liquid crystal display with a display module 1 and a backlight module 2. The display module 1 includes a protective cover 11 and a liquid crystal display panel 12. The liquid crystal display panel 12 can be a touch display panel with a touch detection function, and the protective cover 11 is arranged above the liquid crystal display panel 12 to protect the liquid crystal. The display panel 12 also provides the user with a finger-operated human-computer interaction interface. The backlight module 2 is arranged under the display module 1 to provide a backlight source for the display module 1; the backlight module 2 includes a backlight light source 14, and the visible light emitted by the backlight light source 14 is converted into a uniform ground light source through the backlight module 2 and irradiated The module 1 is displayed to display the screen. It is understandable that the protective cover 11 may be, for example, a glass cover or a sapphire cover. Therefore, in the embodiment of the present application, the so-called finger 13 pressing on the liquid crystal display may actually refer to pressing on the protective cover 11 or A protective layer (such as a tempered film or other protective film) covering the surface of the protective cover plate 11.

Specifically, the first reflective polarizing film layer 3 is the above-mentioned reflective polarizing brightness enhancement film, which has the following characteristics: For light incident on the first reflective polarizing film layer 3, about 50% of the reflection and 50% transmission.

In order to ensure that the detection light emitted by the detection light source 50 and the fingerprint detection light formed by illuminating the finger 13 can pass through the backlight module 2, in this embodiment, at least part of the area of the backlight module 2 is transparent to the fingerprint detection light. The light-transmitting area, the light-transmitting area may specifically be the area corresponding to the transmission path of the detection light and the fingerprint detection light formed on the finger 13 on the liquid crystal display screen, and its transmission band covers the emission band of the detection light source 50, so that the detection light The fingerprint detection light formed on the finger 13 can penetrate the light-transmitting area of the backlight module 2.

In the embodiment of the present application, the backlight module 2 includes a light guide plate 21 and a back plate assembly 22 for fixing the light guide plate 21, etc., and the above-mentioned light-transmitting area may be formed in the following manner: the back plate assembly 22 corresponds to the detection light source 50 The position is provided with a first light-passing hole 23, and the back plate assembly 22 is provided with a second light-passing hole 24 at a position corresponding to the light path guiding structure 6, and the first light-passing hole 23 can transmit the detection light emitted by the detection light source 50. And it is incident into the light guide plate 21, and the second light through hole 24 can transmit the fingerprint detection light passing through the light guide plate 21 and enter the optical path guide structure 6.

In addition, the under-screen optical fingerprint recognition device includes: a detection light source 50, a light path guiding structure 6 and an optical fingerprint sensor 7 arranged under the backlight module 2; wherein the detection light source 50 can be specifically arranged on the backlight module 2 of the liquid crystal display. Below, the detection light source 50 may specifically be a light source with a different wavelength band from the backlight (visible light) provided by the backlight module 2, and it may be used to emit detection light of a specific wavelength, and the detection light of a specific wavelength is used for fingerprint detection on the finger 13 Light.

Specifically, the detection light source 50 can be used to emit detection light to the finger 13 above the liquid crystal display. The detection light is irradiated to the finger 13 through the backlight module 2 and the display module 1, and is formed after being reflected or transmitted by the finger 13. Fingerprint detection light carrying fingerprint information. The optical path guide structure 6 is used to guide the fingerprint detection light reflected by the finger 13 and carrying fingerprint information and passing through the liquid crystal display to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used for The fingerprint information of the finger 13 is obtained according to the fingerprint detection light.

In the embodiment of the present application, the detection light emitted by the detection light source 50 to the finger 13 and the visible light provided by the backlight module 2 are light in different wavelength bands. For example, the detection light in a specific wavelength band may be invisible light outside the visible light band, such as infrared light. Light. In other words, the user cannot see or perceive the detection light used for fingerprint recognition through the display module 1, and the light signal of the image displayed by the display module 1 is the visible light of the backlight module 2. Therefore, the embodiment of the present application can prevent the detection light emitted by the detection light source 50 from causing interference to the display effect of the display module 1.

Wherein, in this embodiment, the detection light emitted by the detection light source 50 may be infrared light or other light signals whose wavelength is outside the visible light band and can realize fingerprint recognition. In this embodiment, the detection light may include but is not limited to infrared light. Light.

In the embodiment of the present application, the optical fingerprint sensor 7 includes an optical sensing array having a plurality of sensing units, and a reading circuit and other auxiliary circuits electrically connected to the optical sensing array. The sensing area of the optical sensing array may correspond to the fingerprint recognition area of the optical fingerprint sensor 7. Wherein, the optical fingerprint sensor 7 may be located below the fingerprint recognition area of the liquid crystal display screen, or may be located in other areas (such as the edge area of the liquid crystal display screen); and, in this embodiment, the optical path guide structure may be used 6 to guide the fingerprint detection light in the fingerprint recognition area to the optical fingerprint sensor 7, so that the optical sensor array can receive the fingerprint detection light to detect the fingerprint information of the finger 13 corresponding to the fingerprint detection light.

As an optional implementation manner, the optical sensing array and other circuits of the optical fingerprint sensor 7 can be fabricated on a chip (Die) through a semiconductor process, wherein the optical sensing array is specifically a photodetector array, which It includes a plurality of photodetectors distributed in an array, and the photodetectors can be used as the above-mentioned optical sensing unit. On the other hand, as described above, the under-screen optical fingerprint recognition device may also include a light path guiding structure 6 and other optical components, and the light path guiding structure 6 and other optical components may be arranged under the fingerprint recognition area of the liquid crystal display; wherein, The optical path guiding structure 6 is mainly used to guide the fingerprint detection light to the optical sensing array of the optical fingerprint sensor 7 for optical detection; the other optical components mentioned above may include a filter layer 71 (Filter), which may be arranged in the optical path guide Between the structure 6 and the optical fingerprint sensor 7, it is used to filter out the interference light passing through the optical path guiding structure 6, so as to prevent the interference light from being received by the optical sensor array and affecting the fingerprint recognition performance.

Among them, in the under-screen optical fingerprint identification device provided in this embodiment, the optical fingerprint sensor 7, the optical path guiding structure 6 and the filter layer 71 may be packaged in the same fixing component 72.

The light path guiding structure 6 can adopt a variety of implementation schemes. As an embodiment, the light path guiding structure 6 may 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. The optical lens layer may be used to converge the fingerprint detection light formed from the finger 13 and passing through the liquid crystal display to the optical sensor array of the optical fingerprint sensor 7 below, so that the optical sensor array can perform optical imaging based on the fingerprint detection light , Thereby obtaining the fingerprint image of the finger 13.

As another alternative embodiment, the optical path guiding structure 6 may specifically be a collimator (Collimator) layer fabricated on a semiconductor silicon wafer or other substrate, which has a plurality of collimator units, and the collimator unit may be specifically Collimation through hole with a certain aspect ratio; when the user performs fingerprint recognition on the LCD screen, in the fingerprint detection light formed by the finger 13 above the LCD screen and passing through the LCD screen, the incident angle is consistent with the collimation The fingerprint detection light whose extension direction of the unit is basically the same can pass through the collimation unit and be received by the sensing unit below it, while the fingerprint detection light with an excessively large incident angle is attenuated by multiple reflections inside the collimation unit. Therefore, each sensing unit can basically only receive the fingerprint detection light formed by the fingerprint lines directly above it, so that the optical sensing array uses the fingerprint detection light detected by each detection unit to obtain the fingerprint image of the finger 13 respectively.

In other embodiments, the optical path guiding structure 6 may also specifically include a micro-lens (Micro-Lens) layer and an optical film layer. The micro-lens layer includes a micro-lens array formed by a plurality of micro-lenses, which may be formed by a semiconductor growth process. Or other processes are formed above the optical sensing array of the optical fingerprint sensor, and each microlens may correspond to one or more sensing units of the optical sensing array. The optical film layer may be formed between the micro lens layer and the optical sensor unit, and it may include at least one light blocking layer with micro holes and a medium layer formed between the light blocking layer and the micro lens layer and the optical sensor array, A passivation layer or a buffer layer, etc., in which at least one light-blocking layer with micro-holes adopts a specific optical design so that the micro-holes are formed between the corresponding micro-lens and the sensing unit, thereby limiting the receiving of the sensing unit Light path. Wherein, the light-blocking layer can block the optical interference between the adjacent microlens and the sensing unit, and the microlens condenses the received light into the microhole at a vertical or oblique specific angle and transmits it to the microhole through the microhole. Sensor unit for optical fingerprint imaging.

In the embodiment of the present application, optionally, the detection light source 50, the light path guiding structure 6 and the optical fingerprint sensor 7 are arranged on the middle frame 15 of the liquid crystal display screen. Specifically, the middle frame 15 is fixed on the back of the back plate assembly 22 of the backlight module 2, and the surface of the middle frame 15 facing the backlight module 2 is provided with a first fixing groove 231 and a second fixing groove 241, and detecting the light source 50 Fixed in the first fixing groove 231, and the first fixing groove 231 communicates with the first light-passing hole 23, and the position of the notch of the first fixing groove 231 corresponds to the first light-passing hole 23; the light path guiding structure 6 and the optical fingerprint sensor 7 are fixed in the second fixing groove 241, and the second fixing groove 241 communicates with the second light-passing hole 24, and the setting position of the notch of the second fixing groove 241 is the same as that of the second light-passing hole. 24 corresponds. Exemplarily, as shown in FIG. 4, the notch size and setting position of the first fixing groove 231 are the same as those of the first light-passing hole 23, and the notch size and setting position of the second fixing groove 241 are the same as those of the second light-passing hole 23. The holes 24 are the same.

In this application, in order to avoid the problem that the reflected light of the first reflective polarizing film layer 3 falls within the field of view of the optical path guiding structure 6 and interferes with the imaging of the fingerprint image, at least one of the detection light and the fingerprint detection light can be made One through the polarization layer 9, the polarization layer 9 is used to filter out the S wave in the detection light and/or fingerprint detection light, the polarization layer 9 is located above the optical fingerprint identification device under the screen; the polarization direction of the polarization layer 9 and the first reflection The polarization direction of the polarizing film layer 3 is the same.

FIG. 5 is a schematic diagram of the working principle of filtering reflected light by the polarizing layer in the under-screen optical fingerprint identification device provided in Embodiment 1 of the application. Below, after the detection light emitted by the detection light source 50 shown in FIG. 5 passes through the polarizing layer 9, S The case where the wave is filtered is taken as an example to describe the filtering principle of the polarizing layer 9.

As shown in FIG. 5, the polarization direction of the polarizing layer 9 is indicated by the symbol "32", and the light passing direction of the first reflective polarizing film layer 3 is indicated by the symbol "31". The polarization direction of the polarizing layer 9 and the first reflection The polarizing film layer 3 has the same transmission polarization direction (light passing direction). As shown in FIG. 5, the detection light emitted by the detection light source 50 has an incident intensity of A. After passing through the polarizing layer 9, the intensity of the S wave is approximately A/2. After being absorbed by the polarizing layer 9, a small amount of unabsorbed S waves and P waves with an intensity of A/2 pass through the polarizing layer 9, and when passing through the first reflective polarizing film layer 3, the polarization direction of the P waves and the first reflection The transmission polarization direction of the polarizing film layer 3 is the same. Therefore, the P wave with an intensity of A/2 passes through the first reflective polarizing film layer 3 with almost no attenuation, and irradiates the finger through the display module. A reflective polarizing film layer 3 reflects a small amount of S waves, and the reflected light intensity is almost zero. In this way, after the detection light emitted by the detection light source 50 is filtered by the polarizing layer 9, there is almost no reflected light even if it is irradiated to the first reflective polarizing film layer 3, which solves the reflected light interference mentioned at the beginning. Imaging problems.

It is understandable that the principle of filtering the S wave in the fingerprint detection light by the polarizing layer 9 is similar to this. The fingerprint detection light generated on the finger 13 is filtered by the polarizing layer 9 after passing through the display module 1. The P wave is transmitted, so even if there is interference reflected light and stray light, it will be filtered out by the polarizing layer 9, so it is possible to avoid the problem of reflected light interfering with imaging.

In addition, the polarization direction of the polarizing layer 9 mentioned above is the same as the polarization direction of the first reflective polarizing film layer 3. Specifically, the polarization direction of the polarizing layer 9 and the polarization direction of the first reflective polarizing film layer 3 are roughly the same. The same, for example, as long as the difference between the two is in the range of -5° to +5°, it can be considered that the filtering effect of the polarizing layer 9 is within the allowable range.

In the embodiments of the present application, the position of the polarizing layer may be that the polarizing layer is arranged on the light-emitting surface of the backlight module, or on the back of the backlight module away from the light-emitting surface, or in the backlight module. That is, the polarizing layer only needs to be provided between the detection light source and the first reflective polarizing film layer.

6 is a schematic diagram of another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application. As shown in FIG. 6, the display module includes a protective cover 11, an upper polarizer 16, and a liquid crystal display panel stacked in sequence. 12. The lower polarizer 17, the first reflective polarizer layer 3; the backlight module includes a diffuser 20, a brightness enhancement film 25, a light guide plate 21, a reflective film 26, a back plate 27, and a back plate protective layer 28 stacked in sequence. An assembly gap 18 is provided between the first reflective polarizing film layer 3 and the diffusion sheet 20, and a black tape 29 is also provided on the side of the diffusion sheet 20 and the brightness enhancement film 25 for shading light, on the side of the light guide plate 21 A backlight light source 14 is also provided. Specifically, the polarizing layer 9 may be provided on the light-emitting surface of the backlight module 2, that is, on the diffuser 20, or may be provided on the back of the backlight module 2 that faces away from the light-emitting surface as shown in FIG. 6. Or, it can also be provided in the diffuser 20, the brightness enhancement film 25, the light guide plate 21, the reflective film 26, the back plate 27, and the back plate protective layer 28, between any two adjacent layers.

Further, as shown in FIG. 4, the polarizing layer 9 can be arranged on the back plate assembly 22. At this time, the polarizing layer 9 can be arranged in the groove 281 by providing the groove 281 on the back plate protective layer 28. Alternatively, the polarizing layer 9 may be provided between the back plate 27 and the reflective film 26, or the polarizing layer 9 may be provided between the back plate 27 and the back plate protective layer 28.

Further, for the setting range of the polarizing layer 9, the polarizing layer 9 can be located at least above the detection light source 50, so that the detection light can pass through the polarizing layer 9 and the liquid crystal display screen to illuminate the finger 13; When the first light-passing hole 23 is provided at a position corresponding to the light source 50, the polarizing layer 9 above the detection light source 50 covers at least the first light-passing hole 23.

FIG. 7 is a schematic diagram of still another structure of the under-screen optical fingerprint identification device provided in the first embodiment of the application. As shown in FIG. 7, as an optional implementation manner, the polarizing layer 9 is located at least above the optical path guiding structure 6 , So that the fingerprint detection light passes through the polarizing layer 9 and enters the light path guiding structure 6. When the second light through hole 24 is provided at the position of the back plate assembly 22 corresponding to the light path guiding structure 6, it is necessary to make the polarizing layer 9 cover at least the first Two light hole 24. In this case, even if the detection light and/or fingerprint detection light irradiated on the first reflective polarizing film layer 3 is reflected, the reflected light first passes through the polarizing layer 9 and then is filtered out, so the reflected light will not This affects the imaging of the optical fingerprint sensor 7.

FIG. 8 is a schematic diagram of still another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of the application. As shown in FIG. 8, as an optional implementation manner, the polarization layer 9 is located above and above the detection light source 50 at the same time. Above the optical path guiding structure 6, the polarizing layer 9 simultaneously covers the first light-passing hole 23 and the second light-passing hole 24, so that the detection light passes through the polarizing layer 9, and after filtering the S wave, it irradiates the finger 13; The fingerprint detection light of 5 passes through the polarizing layer 9 and enters the optical path guiding structure 6 after filtering the S wave, so that the filtering effect of the reflected light is optimal.

In the solution where the polarizing layer 9 covers the second light-passing hole 24, the optical path guiding structure 6 includes an optical lens layer, and the optical lens layer includes one or more aspheric lenses and is used to converge the fingerprint detection light to the optical fingerprint sensor 7. In the above case, the polarizing layer 9 above the optical path guiding structure 6 at least covers the field of view of the optical lens layer. In order to filter out all possible reflected light incident on the light path guiding structure 6 as much as possible.

In the embodiments of this application, FIG. 9 is a schematic diagram of another structure of the under-screen optical fingerprint identification device provided in Embodiment 1 of this application, and FIG. 10 is still another of the under-screen optical fingerprint identification device provided in Embodiment 1 of this application. The schematic diagram of the principle of improving the lighting efficiency in this structure, as shown in Figures 9 and 10, in order to solve the problem of 50% of the light intensity of the reflected interference, the proportion of the transmitted light involved in the imaging of the fingerprint image is relatively small, so that the light source affects the finger. The problem of low lighting efficiency. Without increasing the power and number of the detection light source 50, a second reflective polarizing film layer 5 and a diffuse reflection layer 51 can also be provided, and the second reflective polarizing film layer 5 is provided above the detection light source 50 and the detection light source 50. Between the polarizing layers 9; the detection light source 50 is located between the diffuse reflection layer 51 and the second reflective polarizing film layer 5.

As shown in FIG. 10, the detection light with intensity A emitted by the detection light source 50 passes through the second reflective polarizing film layer 5, the P wave with the intensity A/2 is transmitted through, and the S wave with the intensity A/2 is reflected and irradiated. On the diffuse reflection layer 51. In the figure, the light passing direction of the second reflective polarizing film layer is indicated by the symbol "33".

The S wave with an intensity of A/2 irradiates the diffuse reflection film 51 to diffusely reflect and form divergent light, which disrupts the polarization direction of the S wave and restores it to natural light. The restored natural light passes through the second reflective polarizing film layer. 5. The P wave is transmitted through, and the S wave is reflected and irradiated on the diffuse reflection layer 51.

The above process is repeated continuously, and finally most of the natural light emitted by the detection light source 50 can be converted into P-wave polarized light, and a conversion rate of 80% can usually be achieved, that is, the P-wave intensity that finally passes through the second reflective polarizing film layer 5. It is 0.8A.

In this way, the above-mentioned problem of low illuminating efficiency of the detection light source 50 for the finger 13 can be solved.

The P wave with an intensity of 0.8A transmitted through the second reflective polarizing film layer 5, after passing through the polarizing layer 9, a small amount of unabsorbed S wave and a P wave with an intensity of 0.8A pass through the polarizing layer 9 In the case of the first reflective polarizing film layer 3, the polarization direction of the P wave is the same as the transmission polarization direction of the first reflective polarizing film layer 3. Therefore, the P wave with an intensity of 0.8A passes through the first reflective polarizing film almost without attenuation The layer 3 is irradiated to the finger through the display module. At the same time, the first reflective polarizing film layer 3 reflects a small amount of S waves, and the reflected light intensity is almost zero. In this way, the detection light emitted by the detection light source 50 is strengthened by the second reflective polarizing film layer 5 and the diffuse reflective film 51, and then filtered by the polarizing layer 9, even if it is irradiated to the first reflective polarizing film layer 3. Reflected light will appear, which solves the problem of reflected light interfering with imaging mentioned at the beginning.

As shown in FIG. 9, the second reflective polarizing film layer 5 is disposed on the back plate assembly, and the second reflective polarizing film layer 5 covers at least the first light-passing hole 23. Since the light emitted by the detection light source 50 enters the light guide plate through the first light-passing hole 23, when the second reflective polarizing film layer 5 covers the first light-passing hole 23, the detection light emitted by the detection light source 50 can be Try to convert. It can be understood that the setting range of the diffuse reflection layer 51 should correspond to the second reflection type polarizing film layer 5. Illustratively, the diffuse reflection layer 51 covers the second reflection type polarizing film layer 5 in a plan view.

In the embodiment of the present application, a flexible circuit board FPC 232 is also provided on the middle frame 15, the detection light source 50 is disposed on the flexible circuit board FPC 232, and the diffuse reflection layer 51 is disposed on the side of the flexible circuit board FPC 232 facing the detection light source 50. For example, after the detection light source 50 is arranged on the flexible circuit board FPC 232, the diffuse reflection layer 51 is arranged on the side of the flexible circuit board FPC 232 facing the display module 1, or the flexible circuit board FPC 232 is oriented first A diffuse reflection layer 51 is provided on one side of the display module 1, and then the detection light source 50 is disposed on the diffuse reflection layer 51, or the diffuse reflection layer 51 may also be disposed on the sidewall of the first fixing groove 231 to enhance the contrast The diffuse reflection effect of the probe light.

In the embodiment of the present application, the diffuse reflection layer 51 is a white ink layer or a silver powder layer.

In this embodiment, when light is incident on the first reflective polarizing film layer, the reflected light generated is basically S wave, and the transmitted light generated is basically P wave. The S wave will interfere with the imaging of the fingerprint image. And by providing a polarizing layer above the optical fingerprint recognition device under the screen, and the polarization direction of the polarizing layer is the same as that of the first reflective polarizing film layer, so the detection light and/or fingerprint detection light can be incorporated into the detection light and/or fingerprint detection light through the polarizing layer. The S wave component reflected by the first reflective polarizing film may be filtered out, which can prevent the reflected light from interfering with the imaging of the fingerprint image, thereby improving the fingerprint recognition accuracy of the fingerprint recognition device.

Example two

This embodiment provides an under-screen optical fingerprint identification system that can be applied to a liquid crystal display device on the basis of the first embodiment. FIG. 11 is a schematic structural diagram of the under-screen optical fingerprint identification device provided in the second embodiment of the application, as shown in FIG. 11 As shown, the under-screen optical fingerprint identification system of this embodiment includes a liquid crystal display 200 and the under-screen optical fingerprint identification device 100 described in Embodiment 1. The under-screen optical fingerprint identification device is arranged under the liquid crystal display for detection Fingerprint information of finger 13 above the LCD screen. The under-screen optical fingerprint recognition system can be applied to smart phones, tablet computers, and other mobile terminals or electronic devices that use liquid crystal displays.

In this embodiment, the liquid crystal display includes a display module 1 and a backlight module 2, and a first reflective polarizing film layer 3 located between the display module 1 and the backlight module 2. The backlight module 2 is arranged on the display module The bottom of 1 is used to provide the backlight for the display module 1. The fingerprint detection light formed by the finger 13 above the liquid crystal display is transmitted through the backlight module 2 to the under-screen optical fingerprint identification device below the backlight module 2. The first reflective polarizing film layer 3 is a reflective polarizing brightness enhancement film, which has the following characteristics: For light incident on the first reflective polarizing film layer 3, about 50% reflection and 50% transmission are generated.

The liquid crystal display also includes a polarizing layer 9, which is arranged above the optical fingerprint identification device under the screen, at least one of the detection light and fingerprint detection light passes through the polarizing layer 9, and the polarizing layer 9 is used to filter the detection light and / Or S wave in the fingerprint detection light; the polarization direction of the polarizing layer 9 is the same as the polarization direction of the first reflective polarizing film layer 3.

In this embodiment, the under-screen optical fingerprint recognition device includes: a detection light source 50, a light path guiding structure 6 and an optical fingerprint sensor 7 arranged under the backlight module 2; the detection light source 50 is used to emit detection light, and the detection light passes through the liquid crystal display The screen is irradiated on the finger 13, and the light path guiding structure 6 is used to guide the fingerprint detection light reflected by the finger 13 and carrying fingerprint information and passing through the liquid crystal display to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used to follow the fingerprint The fingerprint information of the finger 13 is acquired by detecting light.

In this embodiment, the structure, installation position, working principle, etc. of the display module 1, the backlight module 2, the polarizing layer 9 and the under-screen optical fingerprint recognition device have been described in detail in the first embodiment, and will not be omitted here. Go into details.

In this embodiment, when light is incident on the first reflective polarizing film layer, the reflected light generated is basically S wave, and the transmitted light generated is basically P wave. The S wave will interfere with the imaging of the fingerprint image. And by providing a polarizing layer above the optical fingerprint recognition device under the screen, and the polarization direction of the polarizing layer is the same as that of the first reflective polarizing film layer, so the detection light and/or fingerprint detection light can be incorporated into the detection light and/or fingerprint detection light through the polarizing layer. It may be filtered out by the S wave component reflected by the first reflective polarizing film, which can prevent the reflected light from interfering with the imaging of the fingerprint image, thereby improving the fingerprint recognition accuracy of the under-screen optical fingerprint recognition system.

Example three

This embodiment provides a liquid crystal display that supports an under-screen fingerprint recognition function, and the under-screen optical fingerprint recognition device 100 described in the first embodiment is provided under the liquid crystal display. The liquid crystal display includes: a display module 1, a backlight module 2, and a first reflective polarizing film layer 3 between the display module 1 and the backlight module 2; the backlight module 2 is arranged under the display module 1, and To provide a backlight for the display module 1, and make the fingerprint detection light formed by the finger 13 above the liquid crystal display pass through the backlight module 2 to illuminate the under-screen optical fingerprint identification device 100 below the backlight module 2, that is, this embodiment In an example, the fingerprint detection light can be transmitted to the light path guiding structure 6 and the optical fingerprint sensor 7 of the under-screen optical fingerprint identification device 100 through the backlight module 2. The first reflective polarizing film layer 3 is a reflective polarizing brightness enhancement film, which has the following characteristics: For light incident on the first reflective polarizing film layer 3, about 50% reflection and 50% transmission are generated.

The liquid crystal display also includes a polarizing layer 9, which is arranged above the optical fingerprint identification device 100 under the screen, at least one of the detection light and fingerprint detection light passes through the polarizing layer 9, and the polarizing layer 9 is used to filter the detection light And/or the S wave in the fingerprint detection light; the polarization direction of the polarizing layer 9 is the same as the polarization direction of the first reflective polarizing film layer 3.

In the liquid crystal display supporting the under-screen fingerprint recognition function provided by this embodiment, when light is incident on the first reflective polarizing film layer, the reflected light generated is basically a wave, and the transmitted light generated is basically a P wave. The wave will interfere with the imaging of the fingerprint image, and by setting a polarizing layer above the under-screen optical fingerprint identification device, and the polarization direction of the polarizing layer is the same as that of the first reflective polarizing film layer, so it can pass through the polarizing layer The detection light and/or fingerprint detection light may be filtered out by the S wave component reflected by the first reflective polarizing film. Therefore, the liquid crystal display provided in this embodiment supports the under-screen fingerprint recognition function, which solves the existing problem. In the technology, the reflected light is likely to cause interference to the imaging of the fingerprint image, thereby improving the accuracy of fingerprint recognition of the liquid crystal display.

Example four

This embodiment improves on whether the polarizing layer 9 is provided on the basis of the first embodiment, and the rest is the same as the first embodiment. Among them, the structure of the display module 1, the backlight module 2, the polarizing layer 9 and the under-screen optical fingerprint identification device , Setting position, working principle, etc. have been described in detail in the first embodiment, and will not be repeated here.

FIG. 12 is a schematic structural diagram of an under-screen optical fingerprint identification device provided in Embodiment 4 of the application. As shown in FIG. 12, the under-screen optical fingerprint identification device of this embodiment is suitable for a display module 1 and a backlight module 2 Liquid crystal display, wherein a first reflective polarizing film layer 3 is arranged between the display module 1 and the backlight module 2. The under-screen optical fingerprint recognition device includes: a detection light source 50, a light path guiding structure 6 and an optical fingerprint sensor 7 arranged under the backlight module 2; the detection light source 50 is used to emit detection light, and part of the detection light passes through the second reflective polarizing film layer 5 After being reflected, it is incident on the diffuse reflection layer 51 for diffuse reflection, so that part of the diffusely reflected light passes through the second reflective polarizing film layer 5 and irradiates the finger 13, and the optical path guiding structure 6 is used to reflect the finger 13 , And carry fingerprint information, and the fingerprint detection light through the liquid crystal display is guided to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used to obtain fingerprint information of the finger 13 according to the fingerprint detection light; the second reflective polarizing film layer 5 is set Above the detection light source 50, the detection light source 50 is located between the diffuse reflective layer 51 and the second reflective polarizing film layer 5; the polarization direction of the second reflective polarizing film layer 5 is the same as the polarization direction of the first reflective polarizing film layer 3 .

In the above solution, when light is incident on the first reflective polarizing film layer 3, the reflected light generated is basically S wave, and the transmitted light generated is basically P wave. This S wave will interfere with the imaging of the fingerprint image. , And by positioning the detection light source 50 between the diffuse reflective layer 51 and the second reflective polarizing film layer 5, and the polarization direction of the second reflective polarizing film layer 5 is the same as the polarization direction of the first reflective polarizing film layer 3, When the detection light source 50 is irradiated on the second reflective polarizing film layer 5, about 50% of the P wave is transmitted through, and the remaining 50% of the S wave is reflected and irradiated on the diffuse reflection layer 51, and irradiated on the diffuse reflection film 51 The S wave will be diffusely reflected to form divergent light, which will disrupt the polarization direction of the S wave and restore it to natural light. The restored natural light passes through the second reflective polarizing film layer 5, the P wave is transmitted through, and the S wave is reflected and irradiated to the diffuser. On the reflective layer 51. The above process is repeated continuously, and finally most of the natural light emitted by the detection light source 50 can be converted into P-wave polarized light, and the conversion rate can usually reach 80%, and the intensity of the reflected S-wave finally generated is about 20%, which is different from the existing Compared with the 50% reflected S wave in the technology, the amount of reflected light is greatly reduced. Therefore, the degree of interference of the reflected light on the imaging of the fingerprint image is reduced, thereby improving the fingerprint recognition accuracy of the under-screen optical fingerprint recognition device 100 rate. For the specific conversion process, please refer to the discussion process in the first embodiment and FIG. 10, which will not be described in detail here.

On the other hand, the intensity of the P wave finally transmitted through the second reflective polarizing film layer 5 is 80%, which is compared with the 50% transmission of the P wave in the prior art, without increasing the power and quantity of the detection light source 50. In this case, the utilization rate of the detection light is improved, so that the detection light source 50 has a higher illuminating efficiency for the finger 13.

Specifically, the under-screen optical fingerprint identification device of this embodiment is suitable for a liquid crystal display screen having a display module 1 and a backlight module 2. The display module 1 includes a protective cover 11 and a liquid crystal display panel 12. The liquid crystal display panel 12 can be a touch display panel with a touch detection function, and the protective cover 11 is arranged above the liquid crystal display panel 12 to protect the liquid crystal. The panel also provides a human-computer interaction interface operated by the finger 13 for the user. The backlight module 2 is arranged under the display module 1 to provide a backlight source for the display module 1; the backlight module 2 includes a backlight light source, and the visible light emitted by the backlight light source is converted into a uniform ground light source by the backlight module 2 and illuminates the display module. Group 1 to make it display the screen. It is understandable that the protective cover 11 may be, for example, a glass cover or a sapphire cover. Therefore, in the embodiment of the present application, the so-called finger 13 pressing on the liquid crystal display may actually refer to pressing on the protective cover 11 or A protective layer (such as a tempered film or other protective film) covering the surface of the protective cover plate 11. In addition, the polarization direction of the second reflective polarizing film layer 5 is the same as the polarization direction of the first reflective polarizing film layer 3, which specifically means that the two are substantially the same, for example, as long as the difference between the two is between -5° and +5. The range of ° can be considered to be within the allowable range.

Among them, the detection light source 50, the light path guiding structure 6, and the optical fingerprint sensor 7 included in the under-screen optical fingerprint identification device and arranged under the backlight module 2 have been described in detail in the first embodiment, and will not be repeated here.

The under-screen optical fingerprint identification device also includes a second reflective polarizing film layer 5 and a diffuse reflective layer 51. The second reflective polarizing film layer 5 is also a reflective polarizing brightness enhancement film, which also has the following characteristics: The light on the reflective polarizing film layer 5 will produce about 50% reflection and 50% transmission.

In addition, diffuse reflection is a phenomenon in which light projected on a rough surface is reflected in various directions. When a beam of parallel incident light hits a rough surface, the surface will reflect the light in all directions. Therefore, although the incident rays are parallel to each other, the normal directions of the points are inconsistent, causing the reflected light to be irregularly reflected in different directions. This kind of reflection is called "diffuse reflection". The diffuse reflection film 51 in this embodiment can irregularly reflect the S waves reflected by the second reflective polarizing film layer 5 in different directions, and finally restore to natural light and irradiate the second reflective polarizing film layer 5 again. .

The second reflective polarizing film layer 5 is arranged above the detection light source 50, which means that the second reflective polarizing film is arranged on the side of the light exit surface of the detection light source 50, so that the detection light emitted by the detection light source 50 can irradiate the second reflective polarized light膜上。 The membrane. When the detection light source 50 is located between the diffuse reflection layer 51 and the second reflection type polarizing film layer 5, the second reflection type polarization film layer 5 can be made to reflect the S wave component in the detection light emitted by the detection light source 50 to the diffuse reflection layer. 51 on. In addition, in order to make the P waves transmitted through the second reflective polarizing film layer 5 smoothly pass through the first reflective polarizing film layer 3, it is also necessary to make the polarization direction of the second reflective polarizing film layer 5 and the first reflective polarizing film The polarization direction of layer 3 is the same.

As shown in FIG. 12, the first light-passing hole 23 on the back plate assembly 22 corresponds to the first fixing groove on the middle frame 15, and the second reflective polarizing film layer 5 needs to cover at least the first light-passing hole 23 For example, a third fixing groove 242 may be provided at the opening of the first light-passing hole 23 facing the detection light source 50, and the second reflective polarizing film layer 5 may be arranged on the third fixing groove on the back plate assembly 22. In the groove 242, the second reflective polarizing film layer 5 covers the light output range of the detection light source 50.

In the embodiment of the present application, the middle frame 15 also has a flexible circuit board FPC 232, the detection light source 50 is arranged on the flexible circuit board FPC 232, and the diffuse reflection layer 51 is arranged on the side of the flexible circuit board FPC 232 facing the detection light source 50. For example, after the detection light source 50 is arranged on the flexible circuit board FPC 232, the diffuse reflection layer 51 is arranged on the side of the flexible circuit board FPC 232 facing the display module 1, or the flexible circuit board FPC 232 is oriented first A diffuse reflection layer 51 is provided on one side of the display module 1, and then the detection light source 50 is disposed on the diffuse reflection layer 51, or the diffuse reflection layer 51 may also be disposed on the sidewall of the first fixing groove 231 to enhance the contrast The diffuse reflection effect of the probe light.

In addition, in order to further reduce reflected waves, a polarization layer can also be provided above the under-screen optical fingerprint identification device. FIG. 13 is a schematic diagram of another structure of the under-screen optical fingerprint identification device provided in the fourth embodiment of the application, as shown in FIG. As shown, at least one of the detection light and the fingerprint detection light passes through the polarizing layer 9. The polarizing layer 9 is used to filter out S waves in the detection light and/or fingerprint detection light, and the polarization direction of the polarizing layer 9 and the first reflection The polarization direction of the polarizing film layer 3 is the same.

Optionally, the polarizing layer 9 is arranged on the light emitting surface of the backlight module, or on the back of the backlight module away from the light emitting surface, or arranged in the backlight module.

Further, the polarizing layer 9 is provided on the back plate assembly 22, and the second reflective polarizing film layer 5 is located between the polarizing layer 9 and the detection light source 50, so that the detection light can pass through the second reflective polarizing film layer 5 and the polarizing layer. 9 and the liquid crystal display is illuminated on the finger 13. As shown in FIG. 13, this arrangement can make the probe light converted by the second reflective polarizing film layer 5 and the diffuse reflection layer 51 pass through the polarizing layer 9. The polarizing layer 9 further filters out a small amount of S waves in the probe light. Avoid the interference of reflected light on fingerprint imaging.

In addition, the back plate protective layer 28 is provided with a fourth fixing groove 243 at positions corresponding to the first light through hole 23 and the second light through hole 24, and the fourth fixing groove 243 is opened in the back plate protective layer 28. On the surface away from the light guide plate 21, the polarizing layer 9 may be disposed in the fourth fixing groove 243, and then the second reflective polarizing film layer 5 is also placed in the fourth fixing groove 243, and is overlapped on the polarizing layer 9 . When the middle frame 15 and the back plate protective layer 28 are attached to each other, the upper surface of the middle frame 15 can be pressed against the lower surface of the second reflective polarizing film layer 5 for positioning.

The setting position and setting range of the polarizing layer 9 have been described in detail in the first embodiment, and will not be repeated here. It can be understood that, in the case where the second reflective polarizing film layer 5 and the diffuse reflective layer 51 are provided in this embodiment, various modifications to the polarizing layer 9 described in the first embodiment can be further included.

In the embodiment of the present application, the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer, and the polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer 3. When the detection light source irradiates the second reflective polarizing film layer, about 50% of the P wave is transmitted through, the remaining 50% of the S wave is reflected and irradiated on the diffuse reflection layer, and 50% of the S wave is irradiated on the diffuse reflection film Diffuse reflection will be formed to form divergent light, which will disrupt the polarization of S wave and restore it to natural light. The restored natural light passes through the second reflective polarizing film layer, P wave is transmitted through, and S wave is reflected and irradiated to the diffuse reflection layer. on. The above process is repeated continuously, and finally, most of the natural light emitted by the detection light source can be converted into P-wave polarized light, and the conversion rate can usually reach 80%, that is, the intensity of the reflected S-wave is about 20%, which is different from the current situation. Compared with the case where 50% of the reflected S wave is generated in the technology, the amount of reflected light is greatly reduced. Therefore, the degree of interference of the reflected light on the imaging of the fingerprint image is reduced, thereby improving the fingerprint recognition accuracy of the under-screen optical fingerprint recognition device rate.

Example five

On the basis of the fourth embodiment, this embodiment provides an under-screen optical fingerprint identification system that can be applied to a liquid crystal display device. The under-screen optical fingerprint identification system of this embodiment includes a liquid crystal display and the under-screen described in the second embodiment. Optical fingerprint identification device 100. The under-screen optical fingerprint identification device 100 is arranged under the liquid crystal display screen, and is used to detect fingerprint information of the finger 13 above the liquid crystal display screen. The under-screen optical fingerprint recognition system can be applied to smart phones, tablet computers, and other mobile terminals or electronic devices that use liquid crystal displays.

In this embodiment, the liquid crystal display includes a display module 1 and a backlight module 2, and a first reflective polarizing film layer 3 located between the display module 1 and the backlight module 2. The backlight module 2 is arranged on the display module 1 below, used to provide a backlight for the display module 1; the first reflective polarizing film layer 3 reflective polarizing brightness enhancement film, which has the following characteristics: for the light incident on the first reflective polarizing film layer 3, Approximately 50% reflection and 50% transmission are produced.

The liquid crystal display screen further includes: a second reflective polarizing film layer 5 and a diffuse reflective layer 51. The second reflective polarizing film layer 5 is arranged above the detection light source 50, and the detection light source 50 is located on the diffuse reflective layer 51 and the second reflective polarizer. Between the film layers 5; the polarization direction of the second reflective polarizing film layer 5 and the polarization direction of the first reflective polarizing film layer 3 are the same.

In this embodiment, the under-screen optical fingerprint recognition device 100 includes: a detection light source 50, a light path guiding structure 6 and an optical fingerprint sensor 7 arranged under the backlight module 2; the detection light source 50 is used to emit detection light, and the detection light passes through the liquid crystal. The display screen illuminates the finger 13, and the light path guiding structure 6 is used to guide the fingerprint detection light reflected by the finger 13 and carrying fingerprint information and passing through the liquid crystal display to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used to follow The fingerprint detection light acquires fingerprint information of the finger 13.

In this embodiment, the structure, installation position, working principle, etc. of the display module 1, the backlight module 2, the polarizing layer 9 and the under-screen optical fingerprint identification device 100 have been described in detail in the first and fourth embodiments. , I won’t repeat it here.

In the embodiment of the present application, the detection light source is located between the diffuse reflective layer and the second reflective polarizing film layer, and the polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer. When the light source irradiates the second reflective polarizing film layer, about 50% of the P wave is transmitted through, the remaining 50% of the S wave is reflected and irradiated on the diffuse reflection layer, and 50% of the S wave is irradiated on the diffuse reflection film. Diffuse reflection is performed to form divergent light, which disrupts the polarization direction of the S wave and restores it to natural light. The restored natural light passes through the second reflective polarizing film layer, the P wave is transmitted through, and the S wave is reflected and irradiated on the diffuse reflection layer. . The above process is repeated continuously, and finally, most of the natural light emitted by the detection light source can be converted into P-wave polarized light, and the conversion rate can usually reach 80%, that is, the intensity of the reflected S-wave is about 20%, which is different from the current situation. Compared with the case where 50% of the reflected S wave is generated in the technology, the amount of reflected light is greatly reduced. Therefore, the degree of interference of the reflected light on the imaging of the fingerprint image is reduced, thereby improving the fingerprint recognition accuracy of the under-screen optical fingerprint recognition device rate.

Example Six

This embodiment provides a liquid crystal display that supports an under-screen fingerprint identification function, and the under-screen optical fingerprint identification device 100 described in the fourth embodiment is provided under the liquid crystal display. The liquid crystal display includes: a display module 1, a backlight module 2, and a first reflective polarizing film layer 3 between the display module 1 and the backlight module 2; the backlight module 2 is arranged under the display module 1, and To provide a backlight source for the display module 1, and transmit the fingerprint detection light formed by the finger 13 above the liquid crystal display to the under-screen optical fingerprint identification device 100 below the backlight module 2. That is, in this embodiment, the backlight module 2 The fingerprint detection light can be transmitted to the optical path guiding structure 6 and the optical fingerprint sensor 7 of the under-screen optical fingerprint identification device 100. The first reflective polarizing film layer 3 has the following characteristics: the light incident on the first reflective polarizing film layer 3 will produce approximately 50% reflection and 50% transmission.

The liquid crystal display also includes: a second reflective polarizing film layer 5 and a diffuse reflective layer 51. The second reflective polarizing film layer 5 is arranged above the detection light source 50, and the detection light source 50 is located on the diffuse reflective layer 51 and the second reflective polarizing film. Between the layers 5; the polarization direction of the second reflective polarizing film layer 5 and the polarization direction of the first reflective polarizing film layer 3 are the same.

In this embodiment, the structure, installation position, working principle, etc. of the display module, the backlight module, the polarizing layer, and the under-screen optical fingerprint identification device have been described in detail in the first embodiment, and will not be repeated here.

In the liquid crystal display supporting the under-screen fingerprint recognition function provided by this embodiment, the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer, and the polarization direction of the second reflective polarizing film layer is the same as that of the first reflective polarizing film layer. The polarization direction of the reflective polarizing film layer is the same. When the detection light source illuminates the second reflective polarizing film layer, about 50% of the P wave is transmitted through, and the remaining 50% of the S wave passes through the second reflective polarizing film layer and diffuse reflection The continuous conversion of the film can finally convert most of the natural light emitted by the detection light source into P-wave polarized light, usually reaching a conversion rate of 80%, that is, the intensity of the reflected S-wave finally generated is about 20%, which is different from the current situation. Compared with the case where 50% of the reflected S wave is generated in the technology, the amount of reflected light is greatly reduced. Therefore, the degree of interference of the reflected light on the imaging of the fingerprint image is reduced, thereby improving the fingerprint recognition accuracy of the under-screen optical fingerprint recognition device rate.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the application, not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the technical solutions described in the foregoing embodiments, or equivalently replace some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present application. range.

Claims

An under-screen optical fingerprint identification device, which is suitable for a liquid crystal display with a display module and a backlight module, wherein a first reflective polarizing film layer is arranged between the display module and the backlight module. Is that

The under-screen optical fingerprint recognition device includes: a detection light source, a light path guiding structure, and an optical fingerprint sensor arranged under the backlight module; the detection light source is used to emit detection light, and the detection light passes through the liquid crystal display The screen is irradiated on the finger, and the light path guiding structure is used to guide the fingerprint detection light reflected by the finger and carrying fingerprint information and passing through the liquid crystal display to the optical fingerprint sensor; for the optical fingerprint sensor The fingerprint information of the finger is obtained according to the fingerprint detection light; and at least one of the detection light and the fingerprint detection light passes through a polarizing layer, and the polarizing layer is used to filter the detection light and/or The S wave in the fingerprint detection light, and the polarization layer is located above the under-screen optical fingerprint identification device;

The polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer.
The under-screen optical fingerprint identification device according to claim 1, wherein the polarizing layer is arranged on the light-emitting surface of the backlight module, or arranged on the back of the backlight module that faces away from the light-emitting surface, Or set in the backlight module.
The under-screen optical fingerprint identification device according to claim 2, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, and the polarizing layer is arranged on the back plate assembly.
The under-screen optical fingerprint identification device according to claim 3, wherein the polarizing layer is located at least above the detection light source, so that the detection light can pass through the polarizing layer and illuminate the liquid crystal display Onto the finger;

In addition, a position of the back plate assembly corresponding to the detection light source is provided with a first light-passing hole, and the polarizing layer above the detection light source at least covers the first light-passing hole.
The under-screen optical fingerprint identification device according to claim 3 or 4, wherein the polarizing layer is located at least above the optical path guide structure, so that the fingerprint detection light passes through the polarizing layer and is incident on the In the light guide structure;

Moreover, a second light-passing hole is provided at a position corresponding to the light path guiding structure of the back plate assembly, and the polarizing layer at least covers the second light-passing hole.
The under-screen optical fingerprint identification device according to claim 5, wherein the optical path guiding structure includes an optical lens layer, and the optical lens layer includes one or more aspheric lenses for detecting the fingerprint Converging on the optical fingerprint sensor, the polarizing layer above the optical path guiding structure at least covers the field of view of the optical lens layer.
The under-screen optical fingerprint identification device according to claim 4, wherein a second reflective polarizing film layer and a diffuse reflective layer are further provided,

The second reflective polarizing film layer is disposed between the detection light source and the polarizing layer above the detection light source; the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer between;

The polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer.
The under-screen optical fingerprint identification device according to claim 7, wherein the second reflective polarizing film layer is disposed on the back plate assembly, and the second reflective polarizing film layer at least covers the The first light-through hole.
The under-screen optical fingerprint identification device according to claim 7, further comprising a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the diffuse reflection layer is arranged on the flexible circuit board. The board FPC faces the side of the detection light source.
The under-screen optical fingerprint identification device according to claim 7, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.
The under-screen optical fingerprint identification device according to any one of claims 1-4, wherein the detection light source, the optical path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display .
An under-screen optical fingerprint identification system, characterized in that it comprises a liquid crystal display and the under-screen optical fingerprint identification device according to any one of claims 1-11, and the under-screen optical fingerprint identification device is arranged on the liquid crystal display. The lower part of the screen is used to detect the fingerprint information of the finger on the upper part of the liquid crystal display.
The under-screen optical fingerprint identification system according to claim 12, wherein the polarizing layer in the liquid crystal display is arranged on the light-emitting surface of the backlight module, or arranged on the back of the backlight module away from the The back of the light-emitting surface or is arranged in the backlight module.
The under-screen optical fingerprint identification system according to claim 13, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, and the polarizing layer is arranged on the back plate assembly.
The under-screen optical fingerprint identification system according to claim 14, wherein the polarizing layer is located at least above the detection light source, so that the detection light can pass through the polarizing layer and illuminate the liquid crystal display Onto the finger;

In addition, a position of the back plate assembly corresponding to the detection light source is provided with a first light-passing hole, and the polarizing layer above the detection light source at least covers the first light-passing hole.
The under-screen optical fingerprint identification system according to claim 14 or 15, wherein the polarizing layer is located at least above the optical path guide structure, so that the fingerprint detection light passes through the polarizing layer and is incident on the In the light guide structure;

Moreover, a second light-passing hole is provided at a position corresponding to the light path guiding structure of the back plate assembly, and the polarizing layer at least covers the second light-passing hole.
The under-screen optical fingerprint identification system according to claim 16, wherein the optical path guiding structure comprises an optical lens layer, and the optical lens layer comprises one or more aspheric lenses for detecting the fingerprint Converging on the optical fingerprint sensor, the polarizing layer above the optical path guiding structure at least covers the field of view of the optical lens layer.
The under-screen optical fingerprint identification system according to claim 15, wherein a second reflective polarizing film layer and a diffuse reflective layer are further provided,

The second reflective polarizing film layer is disposed between the detection light source and the polarizing layer above the detection light source; the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer between;

The polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer.
The under-screen optical fingerprint identification system of claim 18, wherein the second reflective polarizing film layer is disposed on the back plate assembly, and the second reflective polarizing film layer at least covers the The first light-through hole.
The under-screen optical fingerprint identification system according to claim 18, further comprising a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the diffuse reflection layer is arranged on the flexible circuit board. The board FPC faces the side of the detection light source.
The under-screen optical fingerprint identification system of claim 18, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.
The under-screen optical fingerprint identification system according to any one of claims 12-15, wherein the detection light source, the optical path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display .
A liquid crystal display supporting an under-screen fingerprint identification function, the under-screen optical fingerprint identification device according to any one of claims 1-11 is arranged below the liquid crystal display, and it is characterized in that it comprises: a display module, A backlight module and a first reflective polarizing film layer located between the display module and the backlight module;

It also includes a polarization layer, the polarization layer is arranged above the under-screen optical fingerprint identification device, at least one of the detection light and the fingerprint detection light passes through the polarization layer, and the polarization layer is used for Filtering out S waves in the detection light and/or the fingerprint detection light;

The polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer.
The liquid crystal display according to claim 23, wherein the polarizing layer is arranged on the light-emitting surface of the backlight module, or on the back of the backlight module away from the light-emitting surface, or on the back of the backlight module. Inside the backlight module.
22. The liquid crystal display screen of claim 24, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, and the polarizing layer is disposed on the back plate assembly.
The liquid crystal display according to claim 25, wherein the polarizing layer is located at least above the detection light source, so that the detection light passes through the polarizing layer and the liquid crystal display irradiates the On the finger

In addition, a position of the back plate assembly corresponding to the detection light source is provided with a first light through hole, and the polarization layer above the detection light source at least covers the first light through hole.
The liquid crystal display according to claim 25 or 26, wherein the polarizing layer is located at least above the optical path guiding structure, so that the fingerprint detection light passes through the polarizing layer and enters the optical path guiding structure. Structure

Moreover, a second light-passing hole is provided at a position corresponding to the light path guiding structure of the back plate assembly, and the polarizing layer at least covers the second light-passing hole.
The liquid crystal display screen of claim 27, wherein the optical path guiding structure comprises an optical lens layer, and the optical lens layer comprises one or more aspheric lenses for converging the fingerprint detection light to all the On the optical fingerprint sensor, the polarizing layer above the optical path guiding structure at least covers the field of view of the optical lens layer.
The liquid crystal display screen of claim 26, wherein a second reflective polarizing film layer and a diffuse reflective layer are further provided,

The second reflective polarizing film layer is disposed between the detection light source and the polarizing layer above the detection light source; the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer between;

The polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer.
The liquid crystal display screen of claim 29, wherein the second reflective polarizing film layer is disposed on the back plate assembly, and the second reflective polarizing film layer at least covers the first pass Light hole.
The liquid crystal display of claim 29, further comprising a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the diffuse reflection layer is arranged on the flexible circuit board FPC facing toward One side of the detection light source.
The liquid crystal display of claim 29, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.
The liquid crystal display screen according to any one of claims 23-26, wherein the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display screen.
An under-screen optical fingerprint identification device, which is suitable for a liquid crystal display with a display module and a backlight module, wherein a first reflective polarizing film layer is arranged between the display module and the backlight module. Is that

The under-screen optical fingerprint recognition device includes: a detection light source, a light path guiding structure, and an optical fingerprint sensor arranged under the backlight module; the detection light source is used to emit detection light, and part of the detection light passes through the second reflection The polarizing film layer is irradiated on the finger, and part of the probe light is reflected by the second reflective polarizing film layer and then incident on the diffuse reflection layer for diffuse reflection, so that the partially diffusely reflected light passes through the second reflection layer. The reflective polarizing film layer is irradiated on the finger, and the light path guiding structure is used to guide the fingerprint detection light reflected by the finger and carrying fingerprint information and passing through the liquid crystal display to the optical fingerprint sensor The optical fingerprint sensor is used to obtain fingerprint information of the finger according to the fingerprint detection light;

The second reflective polarizing film layer is arranged above the detection light source, and the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer;

The polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer.
The under-screen optical fingerprint identification device according to claim 34, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, and the position of the back plate assembly corresponding to the detection light source is provided The first light-passing hole, the second reflective polarizing film layer is arranged on the back plate assembly, and the second reflective polarizing film layer at least covers the first light-passing hole.
The under-screen optical fingerprint identification device according to claim 35, wherein a polarization layer is further provided, and at least one of the detection light and the fingerprint detection light passes through the polarization layer, and the polarization layer is used for Filtering out S waves in the detection light and/or the fingerprint detection light, and the polarization layer is located above the under-screen optical fingerprint identification device;

The polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer.
The under-screen optical fingerprint identification device according to claim 36, wherein the polarizing layer is arranged on the light-emitting surface of the backlight module, or arranged on the back of the backlight module that faces away from the light-emitting surface, Or set in the backlight module.
The under-screen optical fingerprint identification device according to claim 37, wherein the polarizing layer is provided on the back plate assembly, and the second reflective polarizing film layer is located between the polarizing layer and the detection light source. In between, so that the detection light passes through the second reflective polarizing film layer, the polarizing layer and the liquid crystal display to illuminate the finger.
The under-screen optical fingerprint identification device according to claim 38, wherein a fourth fixing groove is provided on the side of the back plate assembly away from the light guide plate, and the polarizing layer and the second reflective type The polarizing film layers are sequentially stacked in the fourth fixing groove.
The under-screen optical fingerprint identification device according to claim 37 or 38, wherein the polarizing layer is provided on the back plate assembly, and the polarizing layer is located at least above the optical path guide structure, so that the The fingerprint detection light enters the optical path guiding structure through the polarizing layer;

Moreover, a second light-passing hole is provided at a position corresponding to the light path guiding structure of the back plate assembly, and the polarizing layer at least covers the second light-passing hole.
The under-screen optical fingerprint identification device according to claim 40, wherein the optical path guiding structure comprises an optical lens layer, and the optical lens layer comprises one or more aspheric lenses for detecting the fingerprint Converging on the optical fingerprint sensor, the polarizing layer above the optical path guiding structure at least covers the field of view of the optical lens layer.
The under-screen optical fingerprint identification device according to any one of claims 34-38, further comprising a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the diffuse reflection layer is arranged On the side of the flexible circuit board FPC facing the detection light source.
The under-screen optical fingerprint identification device according to any one of claims 34-38, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.
The under-screen optical fingerprint identification device according to any one of claims 34-38, wherein the detection light source, the optical path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display .
An under-screen optical fingerprint identification system, characterized in that it comprises a liquid crystal display and the under-screen optical fingerprint identification device according to any one of claims 34-44, and the under-screen optical fingerprint identification device is arranged on the liquid crystal display. The lower part of the screen is used to detect the fingerprint information of the finger on the upper part of the liquid crystal display.
The under-screen optical fingerprint recognition system according to claim 45, wherein the backlight module includes a back plate assembly for fixing the light guide plate, and the position of the back plate assembly corresponding to the detection light source is provided The first light-passing hole, the second reflective polarizing film layer is arranged on the back plate assembly, and the second reflective polarizing film layer at least covers the first light-passing hole.
The under-screen optical fingerprint identification system according to claim 46, wherein a polarization layer is further provided, and at least one of the detection light and the fingerprint detection light passes through the polarization layer, and the polarization layer is used for Filtering out S waves in the detection light and/or the fingerprint detection light, and the polarization layer is located above the under-screen optical fingerprint identification device;

The polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer.
The under-screen optical fingerprint identification system according to claim 47, wherein the polarizing layer is arranged on the light-emitting surface of the backlight module, or arranged on the back of the backlight module that faces away from the light-emitting surface, Or set in the backlight module.
The under-screen optical fingerprint identification system of claim 48, wherein the polarizing layer is provided on the back plate assembly, and the second reflective polarizing film layer in the liquid crystal display is located on the polarizing layer. And the detection light source, so that part of the detection light passes through the second reflective polarizing film layer, the polarizing layer, and the liquid crystal display to illuminate the finger.
The under-screen optical fingerprint identification system according to claim 49, wherein a fourth fixing groove is provided on the side of the back plate assembly away from the light guide plate, and the polarizing layer and the second reflective type The polarizing film layers are sequentially stacked in the fourth fixing groove.
The under-screen optical fingerprint identification system according to claim 48 or 49, wherein the polarizing layer is provided on the back plate assembly, and the polarizing layer is located at least above the optical path guide structure, so that The fingerprint detection light enters the optical path guiding structure through the polarizing layer;

Moreover, a second light-passing hole is provided at a position corresponding to the light path guiding structure of the back plate assembly, and the polarizing layer at least covers the second light-passing hole.
The under-screen optical fingerprint identification system according to claim 51, wherein the optical path guiding structure includes an optical lens layer, and the optical lens layer includes one or more aspheric lenses for detecting the fingerprint Converging on the optical fingerprint sensor, the polarizing layer above the optical path guiding structure at least covers the field of view of the optical lens layer.
The under-screen optical fingerprint identification system according to any one of claims 45-49, further comprising a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the liquid crystal display The diffuse reflection layer is arranged on the side of the flexible circuit board FPC facing the detection light source.
The under-screen optical fingerprint identification system according to any one of claims 45-49, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.
The under-screen optical fingerprint identification system according to any one of claims 45-49, wherein the detection light source, the optical path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display .
A liquid crystal display screen supporting an under-screen fingerprint identification function. The under-screen optical fingerprint identification device according to any one of claims 34-44 is arranged below the liquid crystal display screen, and is characterized in that it comprises: a display module, A backlight module and a first reflective polarizing film layer located between the display module and the backlight module;

It also includes a second reflective polarizing film layer and a diffuse reflection layer,

The second reflective polarizing film layer is arranged above the detection light source, and the detection light source is located between the diffuse reflection layer and the second reflective polarizing film layer;

The polarization direction of the second reflective polarizing film layer is the same as the polarization direction of the first reflective polarizing film layer.
The liquid crystal display according to claim 56, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, and a position corresponding to the back plate assembly and the detection light source is provided with a first communication A light hole, the second reflective polarizing film layer is arranged on the back plate assembly, and the second reflective polarizing film layer at least covers the first light through hole.
The liquid crystal display according to claim 57, further comprising a polarizing layer, and at least one of the detection light and the fingerprint detection light passes through the polarizing layer, and the polarizing layer is used to filter out The S wave in the detection light and/or the fingerprint detection light, and the polarization layer is located above the under-screen optical fingerprint identification device;

The polarization direction of the polarizing layer is the same as the polarization direction of the first reflective polarizing film layer.
The liquid crystal display according to claim 58, wherein the polarizing layer is arranged on the light-emitting surface of the backlight module, or on the back of the backlight module away from the light-emitting surface, or on the Inside the backlight module.
The liquid crystal display of claim 59, wherein the polarizing layer is provided on the back plate assembly, and the second reflective polarizing film layer is located between the polarizing layer and the detection light source, So that the detection light passes through the second reflective polarizing film layer, the polarizing layer and the liquid crystal display to illuminate the finger.
The liquid crystal display screen of claim 60, wherein a fourth fixing groove is provided on a side of the back plate assembly away from the light guide plate, and the polarizing layer and the second reflective polarizing film layer They are sequentially stacked in the fourth fixing groove.
The liquid crystal display according to claim 59 or 60, wherein the polarizing layer is provided on the back plate assembly, and the polarizing layer is located at least above the optical path guiding structure, so that the fingerprint detection Light passes through the polarizing layer and enters the optical path guiding structure;

Moreover, a second light-passing hole is provided at a position corresponding to the light path guiding structure of the back plate assembly, and the polarizing layer at least covers the second light-passing hole.
The liquid crystal display screen according to claim 62, wherein the optical path guiding structure comprises an optical lens layer, and the optical lens layer comprises one or more aspheric lenses for converging the fingerprint detection light to all the On the optical fingerprint sensor, the polarizing layer above the optical path guiding structure at least covers the field of view of the optical lens layer.
The liquid crystal display screen according to any one of claims 56-60, further comprising a flexible circuit board FPC, the detection light source is arranged on the flexible circuit board FPC, and the diffuse reflection layer is arranged on the The flexible circuit board FPC faces the side of the detection light source.
The liquid crystal display of any one of claims 56-60, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.
The liquid crystal display screen according to any one of claims 56 to 60, wherein the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged on the middle frame of the liquid crystal display screen.