CN111095288B

CN111095288B - Under-screen optical fingerprint identification device and system and liquid crystal display screen

Info

Publication number: CN111095288B
Application number: CN201980004394.9A
Authority: CN
Inventors: 杜灿鸿; 蒋方林
Original assignee: Shenzhen Goodix Technology Co Ltd
Current assignee: Shenzhen Goodix Technology Co Ltd
Priority date: 2019-12-02
Filing date: 2019-12-02
Publication date: 2023-09-05
Anticipated expiration: 2039-12-02
Also published as: WO2021108968A1; CN111095288A

Abstract

The application provides an under-screen optical fingerprint identification device and system and a liquid crystal display screen. The under-screen optical fingerprint recognition device comprises: the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged below the backlight module; the detection light source is used for emitting detection light, the detection light irradiates the finger through the liquid crystal display screen, and the light path guiding structure is used for guiding the fingerprint detection light which is reflected by the finger, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor; the optical fingerprint sensor is used for acquiring fingerprint information of the finger according to the fingerprint detection light; at least one of the detection light and the fingerprint detection light penetrates through a polarizing layer, the polarizing layer is used for filtering S waves in the detection light and/or the fingerprint detection light, and the polarizing layer is positioned above the under-screen optical fingerprint identification device; the polarization direction of the polarization layer is the same as that of the first reflective polarizing film layer. The fingerprint identification method has higher accuracy.

Description

Under-screen optical fingerprint identification device and system and liquid crystal display screen

Technical Field

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

Background

Along with the development of display technology, the identification technology is innovated, changed and developed, and particularly, the fingerprint identification technology of the mobile phone terminal becomes a medium-current column for identification.

The liquid crystal display (Liquid Crystal Display, LCD) screen has the advantages of thin body, power saving, no radiation and the like, and is widely applied to electronic products such as televisions, computers, mobile phones and the like. LCD screens generally require a backlight module to illuminate a liquid crystal panel to display a picture. When the off-screen optical fingerprint recognition technology is applied to a liquid crystal display screen with a reflective polarizing film, the off-screen fingerprint recognition module generally comprises: the fingerprint detection device comprises a lens group, a fingerprint identification chip, a light source and the like, wherein the lens group is arranged under a liquid crystal display screen and consists of at least one lens, the light source emits detection light to irradiate a finger on the surface of the liquid crystal display screen, fingerprint detection light formed by reflection on the finger is transmitted through the liquid crystal display screen and is incident on the lens group, and the lens group gathers the fingerprint detection light and forms a fingerprint image on the fingerprint identification chip, so that the fingerprint identification chip collects and identifies the fingerprint image.

However, in the above fingerprint recognition module, the liquid crystal display includes a reflective polarizing film, and when the light passes through the reflective polarizing film, about 50% of the light is reflected and 50% of the light is transmitted, and when the reflected light falls within the field of view of the lens group, the reflected light interferes with the imaging of the fingerprint image, resulting in low fingerprint recognition accuracy.

Disclosure of Invention

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

The application provides an under-screen optical fingerprint identification device which is suitable for a liquid crystal display screen 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 comprises: the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged below the backlight module; the detection light source is used for emitting detection light, the detection light irradiates the finger through the liquid crystal display screen, and the light path guiding structure is used for guiding the fingerprint detection light which is reflected by the finger, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor; the optical fingerprint sensor is used for acquiring fingerprint information of the finger according to the fingerprint detection light; at least one of the detection light and the fingerprint detection light penetrates through the polarizing layer, the polarizing layer is used for filtering S waves in the detection light and/or the fingerprint detection light, and the polarizing layer is positioned above the under-screen optical fingerprint identification device; the polarization direction of the polarization layer is the same as that of the first reflective polarizing film layer.

In a specific embodiment of the application, the polarizing layer is disposed on the light emitting surface of the backlight module, or disposed on the back surface of the backlight module away from the light emitting surface, or disposed in the backlight module.

In a specific embodiment of the application, 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.

In a specific embodiment of the application, the polarizing layer is at least positioned above the detection light source, so that the detection light irradiates the finger through the polarizing layer and the liquid crystal display screen;

and the position of the backboard component 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 a specific embodiment of the present application, the polarizing layer is at least located above the light path guiding structure, so that fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

and the position of the backboard component corresponding to the light path guiding structure is provided with a second light through hole, and the polarizing layer at least covers the second light through hole.

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

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

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 positioned between the diffuse reflection layer and the second reflective polarizing film layer.

In a 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 at least covers the first light-transmitting hole.

In the specific embodiment of the application, the LED display device further comprises 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 one surface of the flexible circuit board FPC facing the detection light source.

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

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

The application provides an under-screen optical fingerprint identification system which comprises a liquid crystal display screen and the under-screen optical fingerprint identification device, wherein the under-screen optical fingerprint identification device is arranged below the liquid crystal display screen and is used for detecting fingerprint information of a finger above the liquid crystal display screen.

The application provides a liquid crystal display supporting an under-screen fingerprint identification function, the under-screen optical fingerprint identification device is arranged below the liquid crystal display, and the liquid crystal display comprises: the backlight module comprises a display module, a backlight module and a first reflective polarizing film layer arranged between the display module and the backlight module;

Further comprises: the polarizing layer is arranged above the under-screen optical fingerprint identification device, at least one of the detection light and the fingerprint detection light penetrates through the polarizing layer, and the polarizing layer is used for filtering S waves in the detection light and/or the fingerprint detection light;

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

The application also provides an under-screen optical fingerprint identification device, which is suitable for a liquid crystal display screen 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 optical fingerprint identification device comprises: the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged below the backlight module; the detection light source is used for emitting detection light, part of the detection light irradiates the finger through the second reflective polarizing film layer, part of the detection light irradiates the diffuse reflection layer after being reflected by the second reflective polarizing film layer, so that part of the light after diffuse reflection irradiates the finger through the second reflective polarizing film layer, and the light path guiding structure is used for guiding the fingerprint detection light which is reflected by the finger, carries fingerprint information and penetrates the liquid crystal display to the optical fingerprint sensor; the optical fingerprint sensor is used for acquiring 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 arranged 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.

In a specific embodiment of the application, the backlight module comprises a back plate assembly for fixing the light guide plate, a first light through hole is formed in a position, corresponding to the detection light source, of the back plate assembly, 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.

In the specific embodiment of the application, a polarizing layer is further arranged, at least one of the detection light and the fingerprint detection light penetrates through the polarizing layer, the polarizing layer is used for filtering S waves in the detection light and/or the fingerprint detection light, and the polarizing layer is positioned above the under-screen optical fingerprint identification device;

In a specific embodiment of the application, the polarizing layer is disposed on the back plate assembly, and the second reflective polarizing film layer is disposed between the polarizing layer and the detection light source, so that the detection light irradiates the finger through the second reflective polarizing film layer, the polarizing layer and the liquid crystal display.

In a specific embodiment of the application, a fourth fixing groove is formed on one side, away from the light guide plate, of the back plate assembly, and the polarizing layer and the second reflective polarizing film layer are sequentially laminated in the fourth fixing groove.

In a specific embodiment of the application, the polarizing layer is arranged on the backboard component, and the polarizing layer is at least positioned above the light path guiding structure, so that fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

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

Also comprises 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 arranged between the diffuse reflection layer and the second reflective polarizing film layer.

The application provides an under-screen optical fingerprint identification device and system, and a liquid crystal display, wherein the under-screen optical fingerprint identification device is suitable for the liquid crystal display with a display module and a backlight module, a first reflective polarizing film layer is arranged between the display module and the backlight module, and the under-screen optical fingerprint identification device comprises: the detection light source, the light path guiding structure and the optical fingerprint sensor are arranged below the backlight module; the detection light source is used for emitting detection light, the detection light irradiates the finger through the liquid crystal display screen, and the light path guiding structure is used for guiding the fingerprint detection light which is reflected by the finger, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor; the optical fingerprint sensor is used for acquiring fingerprint information of the finger according to the fingerprint detection light; at least one of the detection light and the fingerprint detection light penetrates through the polarizing layer, the polarizing layer is used for filtering S waves in the detection light and/or the fingerprint detection light, and the polarizing layer is positioned above the under-screen optical fingerprint identification device; the polarization direction of the polarization layer is the same as that of the first reflective polarizing film layer. When light is incident on the first reflective polarizing film layer, the generated reflected light is basically S waves, the generated transmitted light is basically P waves, the S waves can interfere with the imaging of the fingerprint image, and the polarization direction of the polarization layer is the same as that of the first reflective polarizing film layer through arranging the polarization layer above the under-screen optical fingerprint identification device, so that the S wave components to be reflected by the first reflective polarizing film in the detection light and/or the fingerprint detection light can be filtered through the polarization layer, the interference of the reflected light on the imaging of the fingerprint image can be avoided, and the fingerprint identification accuracy of the fingerprint identification device is improved.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it will be obvious that the drawings in the following description are some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort to a person skilled in the art.

FIG. 1 is an exploded view of natural light;

FIG. 2 is an exploded front view schematic of natural light;

FIG. 3 is a schematic diagram illustrating the operation of a reflective polarizing brightness enhancement film according to an embodiment of the present application;

fig. 4 is a schematic structural diagram of an optical fingerprint recognition device under a screen according to a first embodiment of the present application;

fig. 5 is a schematic diagram illustrating the working principle of filtering reflected light by a polarizing layer in an optical fingerprint identification device under a screen according to a first embodiment of the present application;

FIG. 6 is a schematic diagram of another structure of an on-screen optical fingerprint recognition device according to an embodiment of the present application;

FIG. 7 is a schematic diagram of an under-screen optical fingerprint recognition device according to an embodiment of the present application;

FIG. 8 is a schematic diagram of an under-screen optical fingerprint recognition device according to an embodiment of the present application;

FIG. 9 is a schematic diagram of an under-screen optical fingerprint recognition device according to an embodiment of the present application;

fig. 10 is a schematic diagram illustrating an improvement of illumination efficiency in still another structure of an optical fingerprint recognition device under a screen according to a first embodiment of the present application;

fig. 11 is a schematic structural diagram of an optical fingerprint recognition device under a screen according to a second embodiment of the present application;

fig. 12 is a schematic structural diagram of an optical fingerprint recognition device under a screen according to a fourth embodiment of the present application;

fig. 13 is a schematic diagram of another structure of an optical fingerprint recognition device under a screen according to a fourth embodiment of the present application.

Reference numerals illustrate:

1-a display module; 2-a backlight module; 3-a first reflective polarizing film layer; 5-a second reflective polarizing film layer; 6-an optical path guiding structure; 7-an optical fingerprint sensor; 9-a polarizing layer; 11-protecting cover plate; 12-a liquid crystal display panel; 13-finger; 14-a backlight source; 15-middle frame; 16-applying a polarizer; 17-a lower polarizer; 18-fitting gap; 20-a diffusion sheet; 21-a light guide plate; 22-a back plate assembly; 23-a first light transmission hole; 24-a second light through hole; 25-brightness enhancement film; 26-a reflective film; 27-a back plate; 28-a back plate protection layer; 29-black tape; 31-the light passing direction of the first reflective polarizing film layer; polarization direction of the 32-polarization layer; 33-the light passing direction of the second reflective polarizing film layer; 50-detecting a light source; 51-a diffuse reflection layer; 71-a filter layer; 72-fixing the component; 80-reflective polarizing brightness enhancement film; 81-LEDs; 100-an under-screen optical fingerprint recognition device; 231-a first fixing groove; 232-a flexible circuit board FPC; 241-a second fixing groove; 242-third fixing groove; 243-fourth fixing grooves; 281-groove.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The technical scheme of the application is described in detail below by specific examples. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.

The liquid crystal display screen comprises a first reflective polarizing film layer, wherein the first reflective polarizing film layer is a reflective polarizing brightness enhancement film (Dual Brightness Enhancement Film, DBEF). Optionally, the liquid crystal display further includes a second reflective polarizing film layer, which is also a reflective polarizing brightness enhancing film, that produces approximately 50% reflection and 50% transmission for light incident on either the first reflective polarizing film layer or the second reflective polarizing film layer.

Specifically, fig. 1 is an exploded schematic view of natural light, and fig. 2 is an exploded front schematic view of natural light. As shown in fig. 1 and 2, light has polarization characteristics, and can be classified into P-waves and S-waves according to the relationship between the polarization direction and the propagation direction (denoted by reference numeral "B" in the figure), the polarization direction of the P-waves being parallel to the propagation plane of the light, and the polarization direction of the S-waves being perpendicular to the propagation plane of the light, and it can be considered that the light is composed of 50% of the P-waves and 50% of the S-waves mixed with respect to natural light.

Fig. 3 is a schematic diagram of the working principle of the reflective polarizing brightness enhancement film according to the embodiment of the present application, wherein the dotted arrow is the light-transmitting direction. As shown in fig. 3, in the present application, an LED 81 is generally used as a detection light source, and the light emitted from the LED 81 is natural light, and assuming that the intensity is a, the intensities of both P-wave and S-wave are a/2. The macroscopic property of the reflective polarizing brightness enhancement film 80 is that when light from the LED 81 is incident on the reflective polarizing brightness enhancement film 80, the reflected light is generated as an S wave, as indicated by the downward arrow in fig. 3; as indicated by the black arrow above the reflective polarizing brightness enhancing film 80, the transmitted light is substantially P-wave. Therefore, the natural light emitted from the LED 81 passes through the reflective polarizing brightness enhancing film 80, and is reflected by about 50% (S-wave component with an intensity of a/2), and transmitted by 50% (P-wave component with an intensity of a/2).

Since the reflective polarizing brightness enhancing film has the above characteristics, when the liquid crystal display includes the first reflective polarizing film layer, about 50% reflection and 50% projection are generated when passing through the first reflective polarizing film layer regardless of the detection light emitted from the light source or the fingerprint detection light formed on the finger. Therefore, the fingerprint identification 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, interference is caused to imaging of a fingerprint image, and fingerprint identification accuracy is not high.

In a second aspect, the intensity of the light that produces the reflected interference is 50% and the proportion of transmitted light that participates in the imaging of the fingerprint image is relatively small, thus making the illumination of the finger by the light source less efficient.

The present application has been made to solve the above-described problems.

Example 1

Fig. 4 is a schematic structural diagram of an optical fingerprint identification device under a screen according to an embodiment of the present application, as shown in fig. 4, the optical fingerprint identification device under a screen according to the present embodiment is suitable for a liquid crystal display having a display module 1 and a backlight module 2, wherein a first reflective polarizing film layer 3 is disposed between the display module 1 and the backlight module 2, and the optical fingerprint identification device under a screen 100 includes: a detection light source 50, an optical path guiding structure 6 and an optical fingerprint sensor 7 arranged below the backlight module 2; the detection light source 50 is used for emitting detection light, the detection light irradiates the finger 13 through the liquid crystal display screen, and the light path guiding structure 6 is used for guiding the fingerprint detection light which is reflected by the finger 13, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used for acquiring fingerprint information of the finger 13 according to fingerprint detection light; at least one of the detection light and the fingerprint detection light passes through the polarizing layer 9, the polarizing layer 9 is used for filtering S waves in the detection light and/or the fingerprint detection light, and the polarizing layer 9 is positioned above the under-screen optical fingerprint identification device; the polarization direction of the polarization layer 9 is the same as that of the first reflective polarizing film layer 3. In the above scheme, when light is incident on the first reflective polarizing film layer 3, the generated reflected light is basically S wave, the generated transmitted light is basically P wave, and the S wave interferes with the imaging of the fingerprint image, and the polarizing layer 9 is disposed above the under-screen optical fingerprint recognition device, and the polarizing direction of the polarizing layer 9 is the same as that of the first reflective polarizing film layer 3, so that the S wave component possibly reflected by the first reflective polarizing film in the detection light and/or the fingerprint detection light can be filtered out by the polarizing layer 9, and the interference of the reflected light on the imaging of the fingerprint image can be avoided, thereby improving the fingerprint recognition accuracy of the fingerprint recognition device.

The under-screen optical fingerprint identification device is suitable for a liquid crystal display screen with a display module 1 and a backlight module 2. The display module 1 includes a protective cover plate 11 and a liquid crystal display panel 12, wherein the liquid crystal display panel 12 may be a touch display panel with a touch detection function, and the protective cover plate 11 is disposed above the liquid crystal display panel 12, and is used for protecting the liquid crystal display panel 12 and providing a human-computer interaction interface for finger operation for a user. The backlight module 2 is arranged below the display module 1 and is used for providing a backlight source for the display module 1; the backlight module 2 includes a backlight source 14, and visible light emitted by the backlight source 14 is converted into a uniform ground light source by the backlight module 2 and irradiates the display module 1 to display a picture. It is understood that the protective cover 11 may be, for example, a glass cover or a sapphire cover, and thus, in the embodiment of the present application, the pressing of the finger 13 against the lcd may actually specifically refer to pressing against the protective cover 11 or a protective layer (such as a tempered film or other protective film) covering the surface of the protective cover 11.

Specifically, the first reflective polarizing film layer 3 is the 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.

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

In the embodiment of the present application, the backlight module 2 includes the light guide plate 21, the back plate assembly 22 for fixing the light guide plate 21, and the like, and the light-transmitting area may be formed by: the position of the back plate assembly 22 corresponding to the detection light source 50 is provided with a first light through hole 23, the position of the back plate assembly 22 corresponding to the light path guiding structure 6 is provided with a second light through hole 24, the first light through hole 23 can enable detection light emitted by the detection light source 50 to penetrate and enter the light guiding plate 21, and the second light through hole 24 can enable fingerprint detection light penetrating through the light guiding plate 21 to penetrate and enter the light path guiding structure 6.

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

Specifically, the detection light source 50 may be used to emit detection light to the finger 13 above the liquid crystal display, where the detection light irradiates the finger 13 through the backlight module 2 and the display module 1, and forms fingerprint detection light carrying fingerprint information after being reflected or transmitted by the finger 13, and the optical path guiding structure 6 is used to guide the fingerprint detection light reflected by the finger 13, carrying fingerprint information, and penetrating the liquid crystal display to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is for acquiring fingerprint information of the finger 13 from 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 different wavelength bands, for example, the detection light in a specific wavelength band may be invisible light, such as infrared light, located outside the visible light wavelength band. That is, the user cannot see or perceive the detection light 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 application can avoid the interference of the detection light emitted by the detection light source 50 on the display effect of the display module 1.

In this embodiment, the detection light emitted by the detection light source 50 may be infrared light or other light signals with wavelengths outside the band of visible light and capable of realizing fingerprint recognition, and in this embodiment, the detection light may include, but is not limited to, infrared light.

In the embodiment of the 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. The optical fingerprint sensor 7 may be located below the fingerprint recognition area of the liquid crystal display screen, or may be located in another area (such as an edge area of the liquid crystal display screen); also, in this embodiment, the fingerprint detection light of the fingerprint identification area may be guided to the optical fingerprint sensor 7 by the optical path guiding structure 6, so that the optical sensing array may receive the fingerprint detection light to detect and obtain the fingerprint information of the finger 13 corresponding to the fingerprint detection light.

As an alternative implementation, the optical sensing array of the optical fingerprint sensor 7, in particular a Photo detector (Photo detector) array, comprising a plurality of Photo detectors distributed in an array, may be fabricated as the optical sensing unit described above, as well as other circuits, by means of a semiconductor process on one chip (Die). On the other hand, as described above, the under-screen optical fingerprint recognition device may further include an optical path guiding structure 6 and other optical components, and the optical path guiding structure 6 and other optical components may be disposed under the fingerprint recognition area of the liquid crystal display; the light path guiding structure 6 is mainly used for guiding fingerprint detection light to the optical sensing array of the optical fingerprint sensor 7 for optical detection; the other optical components may include a Filter layer 71 (Filter), and the Filter layer 71 may be disposed between the optical path guiding structure 6 and the optical fingerprint sensor 7, for filtering the interference light passing through the optical path guiding structure 6, so as to avoid the interference light being received by the optical sensing array and affecting fingerprint recognition performance.

In the optical fingerprint recognition device under the screen provided in this embodiment, the optical fingerprint sensor 7, the optical path guiding structure 6 and the filter layer 71 may be encapsulated in the same fixing component 72.

The light path guiding structure 6 may take a variety of implementations. As an example, the light path guiding structure 6 may be an optical Lens (Lens) layer having one or more Lens units, such as a Lens group consisting of one or more aspherical lenses. The optical lens layer may be used to focus fingerprint detection light formed from the finger 13 and passing through the liquid crystal display onto the optical sensing array of the optical fingerprint sensor 7 thereunder so that the optical sensing array may be optically imaged based on the fingerprint detection light, thereby obtaining a fingerprint image of the finger 13.

As another alternative embodiment, the optical path guiding structure 6 may be a Collimator (Collimator) layer fabricated on a semiconductor silicon wafer or other substrate, which has a plurality of collimating units, and the collimating units may be collimating through holes with a certain aspect ratio; when a user performs fingerprint identification on the liquid crystal display, among fingerprint detection lights which are formed by the finger 13 above the liquid crystal display and pass through the liquid crystal display, the fingerprint detection lights with the incidence angle basically consistent with the extending direction of the collimation unit can pass through the collimation unit and be received by the induction units below the collimation unit, and the fingerprint detection lights with the overlarge incidence angle are attenuated in the collimation unit through multiple reflections, so that each induction unit basically only can receive the fingerprint detection lights formed by the fingerprint lines above the induction units, and the optical induction array can acquire the fingerprint image of the finger 13 by utilizing the fingerprint detection lights detected by the detection units.

In other embodiments, the optical path guiding structure 6 may further specifically include a Micro-Lens layer and an optical film layer, the Micro-Lens layer including a Micro-Lens array formed of a plurality of Micro-lenses, which may be formed over an optical sensing array of the optical fingerprint sensor by a semiconductor growth process or other processes, and each Micro-Lens may respectively correspond to one or more sensing units of the optical sensing array. An optical film layer may be formed between the microlens layer and the optical sensing unit, and may include at least one light blocking layer having micro holes, and a dielectric layer, passivation layer, buffer layer, or the like formed between the light blocking layer and the microlens layer and the optical sensing array, wherein the at least one light blocking layer having micro holes adopts a specific optical design such that the micro holes are formed between their corresponding microlenses and sensing units, thereby defining a receiving optical path of the sensing unit. The light blocking layer can block optical interference between adjacent microlenses and the sensing units, and the microlenses collect received light into the micropores at a specific angle vertical or inclined and transmit the light to the sensing units through the micropores for optical fingerprint imaging.

In an embodiment of the present application, optionally, the detection light source 50, the light path guiding structure 6 and the optical fingerprint sensor 7 are disposed on the middle frame 15 of the liquid crystal display. Specifically, the middle frame 15 is fixed on the back surface 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, the detection light source 50 is fixed in the first fixing groove 231, and the first fixing groove 231 is communicated with the first light through hole 23, and the setting position of the notch of the first fixing groove 231 corresponds to the first light through hole 23; the optical path guiding structure 6 and the optical fingerprint sensor 7 are fixed in the second fixing groove 241, and the second fixing groove 241 and the second light passing hole 24 communicate, and the notch of the second fixing groove 241 is disposed at a position corresponding to the second light passing hole 24. Illustratively, as shown in fig. 4, the notch size and the arrangement position of the first fixing groove 231 are the same as those of the first light passing hole 23, and the notch size and the arrangement position of the second fixing groove 241 are the same as those of the second light passing hole 24.

In the 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 light path guiding structure 6 and interferes with the imaging of the fingerprint image, at least one of the probe light and the fingerprint detection light can penetrate the polarizing layer 9, the polarizing layer 9 is used for filtering out the S wave in the probe light and/or the fingerprint detection light, and the polarizing layer 9 is positioned above the under-screen optical fingerprint identification device; the polarization direction of the polarization layer 9 is the same as that of the first reflective polarizing film layer 3.

Fig. 5 is a schematic diagram illustrating the working principle of filtering reflected light by the polarizing layer in the optical fingerprint identification device under the screen according to the first embodiment of the present application, and the filtering principle of the polarizing layer 9 will be described below by taking the case that the S-wave is filtered after the probe light emitted by the detection light source 50 shown in fig. 5 passes through the polarizing layer 9 as an example.

As shown in fig. 5, the polarization direction of the polarizing layer 9 is denoted by reference numeral 32, and the light passing direction of the first reflective polarizing film 3 is denoted by reference numeral 31, and the polarization direction of the polarizing layer 9 is the same as the transmission polarization direction (light passing direction) of the first reflective polarizing film 3, and as shown in fig. 5, the detection light emitted from the light source 50 is detected, the incident intensity is a, after passing through the polarizing layer 9, the S wave having an intensity of approximately a/2 is absorbed by the polarizing layer 9, and a trace amount of the S wave which is not absorbed and the P wave having an intensity of a/2 are transmitted through the polarizing layer 9, and when passing through the first reflective polarizing film 3, the P wave having an intensity of a/2 is transmitted through the first reflective polarizing film 3 with little attenuation, and is irradiated to the finger through the display module, and at the same time, the reflected light intensity of the S wave having an intensity of approximately a/2 is reflected by the first reflective polarizing film 3. In this way, after the detection light emitted from the detection light source 50 is filtered by the polarizing layer 9, the reflected light hardly appears even if it is irradiated to the first reflective polarizing film layer 3, which solves the problem of the reflected light interfering with imaging mentioned at the beginning.

It can be understood that the principle of filtering the S-wave in the fingerprint detection light by the polarizing layer 9 is similar to that, the fingerprint detection light generated on the finger 13 is filtered by the polarizing layer 9 after passing through the display module 1, and only the P-wave passes through, so that even if there is interference reflected light and stray light, the interference reflected light is filtered by the polarizing layer 9, and thus the problem of interference imaging of the reflected light can be avoided.

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

In the embodiment of the present application, the setting position of the polarizing layer may be that the polarizing layer is disposed on the light emitting surface of the backlight module, or disposed on the back surface of the backlight module away from the light emitting surface, or disposed in the backlight module. That is, the polarizing layer may be provided between the detection light source and the first reflective polarizing film layer.

Fig. 6 is a schematic diagram of another structure of an optical fingerprint recognition device under a screen according to a first embodiment of the present application, as shown in fig. 6, a display module includes a protective cover plate 11, an upper polarizer 16, a liquid crystal display panel 12, a lower polarizer 17, and a first reflective polarizing film layer 3 stacked in order; the backlight module includes a diffusion sheet 20, a brightness enhancement film 25, a light guide plate 21, a reflection film 26, a back plate 27, and a back plate protection layer 28, which are sequentially stacked. An assembly gap 18 is provided between the first reflective polarizing film layer 3 and the diffusion sheet 20, a black tape 29 is further provided on the sides of the diffusion sheet 20 and the brightness enhancement film 25 for shielding light, and a backlight source 14 is further provided on the side of the light guide plate 21. Specifically, the polarizing layer 9 may be disposed on the light exit surface of the backlight module 2, that is, the diffusion sheet 20, or may be disposed on the back surface of the backlight module 2 facing away from the light exit surface as shown in fig. 6. Or may be provided between any two adjacent layers of the diffusion sheet 20, the brightness enhancement film 25, the light guide plate 21, the reflection film 26, the back sheet 27, and the back sheet protection layer 28.

Further, as shown in fig. 4, the polarizing layer 9 may be disposed on the back plate assembly 22. At this time, the polarizing layer 9 may be disposed in the groove 281 by providing the groove 281 on the back plate protection layer 28. Alternatively, the polarizing layer 9 may be disposed between the back plate 27 and the reflective film 26, or the polarizing layer 9 may be disposed 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 may be positioned at least above the detection light source 50, so that the detection light irradiates the finger 13 through the polarizing layer 9 and the liquid crystal display; in the case where the first light-passing hole 23 is provided at a position of the back plate assembly 22 corresponding to the detection 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 an optical fingerprint recognition device under a screen according to an embodiment of the present application, as shown in fig. 7, as an alternative embodiment, the polarizing layer 9 is at least located above the optical path guiding structure 6, so that fingerprint detection light is incident into the optical path guiding structure 6 through the polarizing layer 9, and when the second light through holes 24 are provided at positions of the back plate assembly 22 corresponding to the optical path guiding structure 6, the polarizing layer 9 needs to cover at least the second light through holes 24. In this case, even if the detection light and/or the fingerprint detection light irradiated onto the first reflective polarizing film layer 3 are reflected, the reflected light passes through the polarizing layer 9 and is filtered out, and thus the reflected light does not affect the imaging of the optical fingerprint sensor 7.

Fig. 8 is a schematic diagram of still another structure of an optical fingerprint recognition device under a screen according to an embodiment of the present application, as shown in fig. 8, as an alternative implementation manner, a polarizing layer 9 is located above a detection light source 50 and above an optical path guiding structure 6, and the polarizing layer 9 covers the first light-passing hole 23 and the second light-passing hole 24 at the same time, so that the detection light passes through the polarizing layer 9, and the S-wave is filtered and irradiated onto a finger 13; and the formed fingerprint detection light is transmitted through the polarizing layer 9, and the S wave is filtered and then is incident into the light path guiding structure 6, so that the filtering effect on the reflected light is optimal.

In the case where the polarizing layer 9 covers the second light through hole 24, the polarizing layer 9 above the light path guiding structure 6 covers at least the field of view of the optical lens layer in case the light path guiding structure 6 comprises an optical lens layer comprising one or more aspherical lenses for converging fingerprint detection light onto the optical fingerprint sensor 7. To filter out as much as possible all reflected light that may be incident on the light path guiding structure 6.

In the embodiment of the present application, fig. 9 is a schematic diagram of still another structure of an optical fingerprint recognition device under a screen provided in the first embodiment of the present application, and fig. 10 is a schematic diagram of a principle of improving illumination efficiency in still another structure of an optical fingerprint recognition device under a screen provided in the first embodiment of the present application, as shown in fig. 9 and 10, in order to solve the problem that the illumination efficiency of a finger by a light source is low due to relatively small proportion of transmitted light that participates in fingerprint image imaging because the intensity of light that generates reflection interference is 50%. The second reflective polarizing film layer 5 and the diffuse reflection layer 51 may be further provided without increasing the power and the number of the detection light sources 50, the second reflective polarizing film layer 5 being provided between the detection light sources 50 and the polarizing layer 9 above the detection light sources 50; 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 from the detection light source 50 passes through the second reflective polarizing film layer 5, the P wave with intensity a/2 passes through, and the S wave with intensity a/2 is reflected and irradiated onto the diffuse reflection layer 51. The direction of light passing through the second reflective polarizing film layer is shown by reference numeral 33.

The S wave with the intensity of a/2 irradiates the diffuse reflection film 51 to diffuse reflect and form divergent light, the direction of the polarized light of the S wave is disturbed and reduced to natural light, the reduced natural light passes through the second reflective polarizing film layer 5, the p wave is transmitted, and the S wave is reflected and irradiated to the diffuse reflection layer 51.

The above process is repeated continuously, and most of the natural light emitted from the detection light source 50 can be converted into P-wave polarized light, which can reach 80% conversion rate, that is, the P-wave intensity of the light transmitted through the second reflective polarizing film layer 5 is 0.8A.

Thus, the problem of the low illumination efficiency of the finger 13 by the detection light source 50 can be solved.

When the P-wave having an intensity of 0.8A transmitted through the second reflective polarizing film 5 passes through the polarizing layer 9, a small amount of unabsorbed S-wave and the P-wave having an intensity of 0.8A transmitted through the polarizing layer 9, and passes through the first reflective polarizing film 3, the P-wave having an intensity of 0.8A transmitted through the first reflective polarizing film 3 with little attenuation, and transmitted through the display module, and irradiated to the finger, and at the same time, the first reflective polarizing film 3 reflects a small amount of S-wave, 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 reflection film 51, and after being filtered by the polarizing layer 9, no reflected light will appear even if the detection light irradiates the first reflective polarizing film layer 3, which solves the problem of interference imaging of the reflected light mentioned at the beginning.

As shown in fig. 9, the second reflective polarizing film 5 is disposed on the back plate assembly, and the second reflective polarizing film 5 covers at least the first light-transmitting hole 23. Since the light emitted from the detection light source 50 is incident on the light guide plate through the first light-passing hole 23, the detection light emitted from the detection light source 50 can be converted as much as possible when the second reflective polarizing film layer 5 covers the first light-passing hole 23. It is understood that the diffuse reflection layer 51 is disposed in a range corresponding to the second reflective polarizing film layer 5, and the diffuse reflection layer 51 is illustratively disposed to cover the second reflective polarizing film layer 5 in a plan view.

In the embodiment of the present application, the flexible circuit board FPC 232 is further disposed 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 a surface of the flexible circuit board FPC 232 facing the detection light source 50. For example, after the detection light source 50 is disposed on the flexible circuit board FPC 232, the diffuse reflection layer 51 is disposed on a side of the flexible circuit board FPC 232 facing the display module 1, or the diffuse reflection layer 51 is disposed on a side of the flexible circuit board FPC 232 facing 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 be disposed on a side wall of the first fixing groove 231, so as to enhance the diffuse reflection effect on the detection 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 generated reflected light is basically an S wave, the generated transmitted light is basically a P wave, and the S wave interferes with the imaging of the fingerprint image, and the polarizing layer is disposed above the optical fingerprint recognition device under the screen, and the polarizing direction of the polarizing layer is the same as that of the first reflective polarizing film layer, so that the S wave component possibly reflected by the first reflective polarizing film in the detection light and/or the fingerprint detection light can be filtered out by the polarizing layer, so that the interference of the reflected light on the imaging of the fingerprint image can be avoided, and the fingerprint recognition accuracy of the fingerprint recognition device is improved.

Example two

The first embodiment provides an optical fingerprint recognition system under a screen, which can be applied to a liquid crystal display device, and fig. 11 is a schematic structural diagram of the optical fingerprint recognition device under a screen provided by the second embodiment of the present application, as shown in fig. 11, where the optical fingerprint recognition system under a screen includes a liquid crystal display 200 and the optical fingerprint recognition device under a screen 100 described in the first embodiment, and the optical fingerprint recognition device under a screen is disposed below the liquid crystal display and is used for detecting fingerprint information of a finger 13 above the liquid crystal display. The under-screen optical fingerprint identification system can be applied to smart phones, tablet computers and other mobile terminals or electronic equipment adopting liquid crystal display screens.

In this embodiment, the liquid crystal display includes a display module 1, a backlight module 2, and a first reflective polarizing film layer 3 disposed between the display module 1 and the backlight module 2, where the backlight module 2 is disposed below the display module 1 and is used for providing a backlight source for the display module 1, and fingerprint detection light formed by a finger 13 above the liquid crystal display is transmitted to an under-screen optical fingerprint identification device below the backlight module 2 through the backlight module 2. The first reflective polarizing film layer 3 is a reflective polarizing brightness enhancement film, and 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 further includes: the polarizing layer 9 is arranged above the under-screen optical fingerprint identification device, at least one of the detection light and the fingerprint detection light penetrates through the polarizing layer 9, and the polarizing layer 9 is used for filtering S waves in the detection light and/or the fingerprint detection light; the polarization direction of the polarization layer 9 is the same as that of the first reflective polarizing film layer 3.

In this embodiment, the under-screen optical fingerprint recognition device includes: a detection light source 50, an optical path guiding structure 6 and an optical fingerprint sensor 7 arranged below the backlight module 2; the detection light source 50 is used for emitting detection light, the detection light irradiates the finger 13 through the liquid crystal display screen, and the light path guiding structure 6 is used for guiding the fingerprint detection light which is reflected by the finger 13, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is for acquiring fingerprint information of the finger 13 from the fingerprint detection light.

In this embodiment, the structure, the setting position, the 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 are not described here again.

In this embodiment, when light is incident on the first reflective polarizing film layer, the generated reflected light is basically an S wave, the generated transmitted light is basically a P wave, and the S wave interferes with the imaging of the fingerprint image, and the polarizing layer is disposed above the optical fingerprint recognition device under the screen, and the polarizing direction of the polarizing layer is the same as that of the first reflective polarizing film layer, so that in the detection light and/or the fingerprint detection light, the S wave component possibly reflected by the first reflective polarizing film is filtered out by the polarizing layer, so that the interference of the reflected light on the imaging of the fingerprint image can be avoided, thereby improving the fingerprint recognition accuracy of the optical fingerprint recognition system under the screen.

Example III

The present embodiment provides a liquid crystal display screen supporting an on-screen fingerprint identification function, and the under-screen optical fingerprint identification device 100 according to the first embodiment is disposed below the liquid crystal display screen. The liquid crystal display includes: the backlight module comprises a display module 1, a backlight module 2 and a first reflective polarizing film layer 3 positioned between the display module 1 and the backlight module 2; the backlight module 2 is disposed below the display module 1, and is configured to provide a backlight source for the display module 1, and enable fingerprint detection light formed by the finger 13 above the liquid crystal display to irradiate the under-screen optical fingerprint recognition device 100 below the backlight module 2 through the backlight module 2, that is, in this embodiment, the fingerprint detection light may be transmitted to the optical path guiding structure 6 and the optical fingerprint sensor 7 of the under-screen optical fingerprint recognition device 100 through the backlight module 2. The first reflective polarizing film layer 3 is a reflective polarizing brightness enhancement film, and 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 further includes: the polarizing layer 9, the polarizing layer 9 is arranged above the under-screen optical fingerprint identification device 100, at least one of the detection light and the fingerprint detection light passes through the polarizing layer 9, and the polarizing layer 9 is used for filtering out S waves in the detection light and/or the fingerprint detection light; the polarization direction of the polarization layer 9 is the same as that of the first reflective polarizing film layer 3.

In the liquid crystal display screen supporting the fingerprint identification function under the screen provided by the embodiment, when light is incident on the first reflective polarizing film layer, the generated reflected light is basically a wave, the generated transmitted light is basically a P wave, the S wave can interfere with the imaging of the fingerprint image, and the polarizing layer is arranged above the optical fingerprint identification device under the screen, and the polarizing direction of the polarizing layer is the same as that of the first reflective polarizing film layer, so that the detection light and/or the fingerprint detection light can be filtered by the S wave component reflected by the first reflective polarizing film through the polarizing layer.

Example IV

The present embodiment improves whether to provide the polarizing layer 9 based on the implementation one, and the rest is the same as the implementation one, wherein the structure, the setting position, the 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 implementation one, and are not repeated here.

Fig. 12 is a schematic structural diagram of an optical fingerprint identification device under a screen according to a fourth embodiment of the present application, as shown in fig. 12, the optical fingerprint identification device under a screen according to the present embodiment is suitable for a liquid crystal display having a display module 1 and a backlight module 2, wherein a first reflective polarizing film layer 3 is disposed between the display module 1 and the backlight module 2. The under-screen optical fingerprint recognition device comprises: a detection light source 50, an optical path guiding structure 6 and an optical fingerprint sensor 7 arranged below the backlight module 2; the detection light source 50 is used for emitting detection light, part of the detection light is reflected by the second reflective polarizing film layer 5 and then enters the diffuse reflection layer 51 for diffuse reflection, so that part of the light after diffuse reflection passes through the second reflective polarizing film layer 5 and irradiates the finger 13, and the light path guiding structure 6 is used for guiding fingerprint detection light which is reflected by the finger 13, carries fingerprint information and passes through the liquid crystal display screen to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is used for acquiring fingerprint information of the finger 13 according to fingerprint detection light; the second reflective polarizing film layer 5 is arranged above the detection light source 50, and the detection light source 50 is arranged between the diffuse reflection 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 that of the first reflective polarizing film layer 3.

In the above-described configuration, when light is incident on the first reflective polarizing film layer 3, the reflected light generated is substantially S-wave, the transmitted light generated is substantially P-wave, the S-wave interferes with the imaging of the fingerprint image, and by locating the detection light source 50 between the diffuse reflection film 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 that of the first reflective polarizing film layer 3, when the detection light source 50 irradiates the second reflective polarizing film layer 5, about 50% of the P-wave is transmitted, the remaining 50% of the S-wave is reflected and irradiates the diffuse reflection film layer 51, the S-wave irradiated to the diffuse reflection film 51 is diffusely reflected to form divergent light, the polarization direction of the S-wave is disturbed and reduced to natural light, the reduced natural light passes through the second reflective polarizing film layer 5, and the P-wave is reflected and irradiates the diffuse reflection film 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, which can generally reach 80% of conversion rate, and the intensity of the finally generated reflected S-wave is about 20%, which greatly reduces the amount of reflected light compared with the case of generating 50% of reflected S-wave in the prior art, thus reducing the degree of interference of the reflected light on the imaging of the fingerprint image, and improving the fingerprint identification accuracy of the under-screen optical fingerprint identification device 100. The specific conversion process may refer to the first embodiment and the discussion process in fig. 10, and will not be described in detail herein.

On the other hand, the intensity of the P-wave finally transmitted through the second reflective polarizing film layer 5 is 80%, which improves the utilization rate of the detection light and makes the illumination efficiency of the detection light source 50 on the finger 13 higher under the condition that the power and the number of the detection light sources 50 are not increased compared with the prior art that only 50% of the P-wave is transmitted.

Specifically, the under-screen optical fingerprint identification device of the embodiment is suitable for a liquid crystal display screen 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, wherein the liquid crystal display panel 12 may be a touch display panel with a touch detection function, and the protective cover 11 is disposed above the liquid crystal display panel 12 and is used for protecting the liquid crystal panel and providing a human-computer interaction interface operated by fingers 13 for a user. The backlight module 2 is arranged below the display module 1 and is used for providing a backlight source for the display module 1; the backlight module 2 comprises a backlight source, and visible light emitted by the backlight source is converted into uniform ground light source by the backlight module 2 and irradiates the display module 1 so as to display a picture. It is understood that the protective cover 11 may be, for example, a glass cover or a sapphire cover, and thus, in the embodiment of the present application, the pressing of the finger 13 against the lcd may actually specifically refer to pressing against the protective cover 11 or a protective layer (such as a tempered film or other protective film) covering the surface of the protective cover 11. The polarization direction of the second reflective polarizing film layer 5 is the same as that of the first reflective polarizing film layer 3, specifically, it means that the two are substantially the same, and for example, it is considered that the difference between them is within the allowable range as long as the difference is within the range of-5 ° to +5°.

The detection light source 50, the light path guiding structure 6, the optical fingerprint sensor 7, and the like, which are disposed below the backlight module 2, included in the under-screen optical fingerprint recognition device are described in detail in the first embodiment, and are not described herein again.

The optical fingerprint identification device under the screen further comprises a second reflective polarizing film layer 5 and a diffuse reflection layer 51, wherein the second reflective polarizing film layer 5 is also a reflective polarizing brightness enhancement film, and has the following characteristics: about 50% reflection and 50% transmission are generated for light incident on the second reflective polarizing film layer 5.

Further, diffuse reflection is a phenomenon in which light projected on a rough surface is reflected in various directions. When a parallel incident beam of light strikes a rough surface, the surface reflects the light in all directions, so that the incident beams are parallel to each other, and the reflected light is irregularly reflected in different directions due to the non-uniform normal directions of each point, and the reflection is called diffuse reflection. The diffuse reflection film 51 in this embodiment can irregularly reflect the S-wave reflected by the second reflective polarizing film layer 5 in different directions, and finally, the S-wave is reduced to natural light and irradiated onto the second reflective polarizing film layer 5 again.

The second reflective polarizing film layer 5 is disposed above the detection light source 50, that is, the second reflective polarizing film is disposed on the light-emitting surface side of the detection light source 50, so that the detection light emitted from the detection light source 50 can be irradiated onto the second reflective polarizing film. When the detection light source 50 is located between the diffuse reflection layer 51 and the second reflective polarizing film layer 5, the second reflective polarizing film layer 5 may reflect the S-wave component of the detection light emitted from the detection light source 50 onto the diffuse reflection layer 51. In order to smoothly pass the P-wave passing through the second reflective polarizing film 5 through the first reflective polarizing film 3, the polarization direction of the second reflective polarizing film 5 and the polarization direction of the first reflective polarizing film 3 need to be 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, so that the second reflective polarizing film 5 needs to cover at least the first light-passing hole 23, for example, a third fixing groove 242 may be disposed at an aperture of the first light-passing hole 23 facing the detection light source 50, and the second reflective polarizing film 5 may be disposed in the third fixing groove 242 on the back plate assembly 22, so that the second reflective polarizing film 5 covers the light-emitting range of the detection light source 50.

In addition, in order to further reduce the reflected wave, a polarizing layer may be disposed above the under-screen optical fingerprint recognition device, and fig. 13 is a schematic diagram of another structure of the under-screen optical fingerprint recognition device according to the fourth embodiment of the present application, as shown in fig. 13, at least one of the probe light and the fingerprint detection light passes through the polarizing layer 9, the polarizing layer 9 is used for filtering out the S wave in the probe light and/or the fingerprint detection light, and the polarizing direction of the polarizing layer 9 is the same as the polarizing direction of the first reflective polarizing film layer 3.

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

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

In addition, a fourth fixing groove 243 is further disposed on the back plate protection layer 28 at a position corresponding to the first light through hole 23 and the second light through hole 24, the fourth fixing groove 243 is disposed on a surface of the back plate protection layer 28 facing 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 disposed in the fourth fixing groove 243 and is overlapped on the polarizing layer 9. When the middle frame 15 is attached to the back plate protection layer 28, the upper surface of the middle frame 15 may abut against the lower surface of the second reflective polarizing film layer 5 to position the same.

The setting position, setting range, etc. of the polarizing layer 9 have been described in detail in the embodiment, and are not described here again. It will be appreciated that this embodiment may further include the various modifications of the polarizing layer 9 described in the first embodiment, in the case where the second reflective polarizing film layer 5 and the diffuse reflective layer 51 are provided.

In the embodiment of the application, the detection light source is arranged 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 that of the first reflective polarizing film layer 3, when the detection light source irradiates on the second reflective polarizing film layer, about 50% of P waves are transmitted, the rest 50% of S waves are reflected and irradiated on the diffuse reflection layer, 50% of S waves irradiate on the diffuse reflection film and are diffusely reflected to form divergent light, the polarization direction of the S waves is disordered to be reduced to natural light, the reduced natural light passes through the second reflective polarizing film layer, the P waves are transmitted, and the S waves are reflected and irradiated on the diffuse reflection layer. The process is repeated continuously, and finally, most of natural light emitted by the detection light source can be converted into P-wave polarized light, so that the conversion rate can be generally 80%, namely, the intensity of finally generated reflected S waves is about 20%, compared with the condition that 50% of reflected S waves are generated in the prior art, the quantity of the reflected light is greatly reduced, the degree of imaging interference of the reflected light on fingerprint images is reduced, and the fingerprint identification accuracy of the under-screen optical fingerprint identification device is improved.

Example five

The present embodiment provides an optical fingerprint recognition system under a screen, which is applicable to a liquid crystal display device, and the optical fingerprint recognition system under a screen in this embodiment includes a liquid crystal display screen and the optical fingerprint recognition device under a screen 100 in the second embodiment, where the optical fingerprint recognition device under a screen 100 is disposed below the liquid crystal display screen, and is used for detecting fingerprint information of a finger 13 above the liquid crystal display screen. The under-screen optical fingerprint identification system can be applied to smart phones, tablet computers and other mobile terminals or electronic equipment adopting liquid crystal display screens.

In this embodiment, the liquid crystal display includes a display module 1, a backlight module 2, and a first reflective polarizing film layer 3 disposed between the display module 1 and the backlight module 2, where the backlight module 2 is disposed below the display module 1 and is used for providing a backlight source for the display module 1; 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 includes further including: a second reflective polarizing film layer 5 and a diffuse reflection layer 51, the second reflective polarizing film layer 5 being disposed above the detection light source 50, the detection light source 50 being located between the diffuse reflection 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 that of the first reflective polarizing film layer 3.

In this embodiment, the under-screen optical fingerprint recognition device 100 includes: a detection light source 50, an optical path guiding structure 6 and an optical fingerprint sensor 7 arranged below the backlight module 2; the detection light source 50 is used for emitting detection light, the detection light irradiates the finger 13 through the liquid crystal display screen, and the light path guiding structure 6 is used for guiding the fingerprint detection light which is reflected by the finger 13, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor 7; the optical fingerprint sensor 7 is for acquiring fingerprint information of the finger 13 from the fingerprint detection light.

In this embodiment, the structure, the setting position, the working principle, etc. of the display module 1, the backlight module 2, the polarizing layer 9 and the under-screen optical fingerprint recognition device 100 have been described in detail in the first embodiment and the fourth embodiment, and are not described here again.

In the embodiment of the application, the detection light source is arranged 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 that of the first reflective polarizing film layer, when the detection light source irradiates on the second reflective polarizing film layer, about 50% of P waves are transmitted, the rest 50% of S waves are reflected and irradiated on the diffuse reflection layer, 50% of S waves irradiate on the diffuse reflection film and are diffusely reflected to form divergent light, the polarization direction of the S waves is disordered to restore to natural light, the restored natural light passes through the second reflective polarizing film layer, the P waves are transmitted, and the S waves are reflected and irradiated on the diffuse reflection layer. The process is repeated continuously, and finally, most of natural light emitted by the detection light source can be converted into P-wave polarized light, so that the conversion rate can be generally 80%, namely, the intensity of finally generated reflected S waves is about 20%, compared with the condition that 50% of reflected S waves are generated in the prior art, the quantity of the reflected light is greatly reduced, the degree of imaging interference of the reflected light on fingerprint images is reduced, and the fingerprint identification accuracy of the under-screen optical fingerprint identification device is improved.

Example six

The present embodiment provides a liquid crystal display screen supporting an on-screen fingerprint identification function, and the under-screen optical fingerprint identification device 100 described in the fourth embodiment is disposed below the liquid crystal display screen. The liquid crystal display includes: the backlight module comprises a display module 1, a backlight module 2 and a first reflective polarizing film layer 3 positioned between the display module 1 and the backlight module 2; the backlight module 2 is disposed below the display module 1, and is configured to provide a backlight source for the display module 1, and transmit fingerprint detection light formed by the finger 13 above the liquid crystal display to the under-screen optical fingerprint recognition device 100 below the backlight module 2, that is, in this embodiment, the backlight module 2 may transmit the fingerprint detection light to the optical path guiding structure 6 and the optical fingerprint sensor 7 of the under-screen optical fingerprint recognition device 100. 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 further includes: a second reflective polarizing film layer 5 and a diffuse reflection layer 51, the second reflective polarizing film layer 5 being disposed above the detection light source 50, the detection light source 50 being located between the diffuse reflection 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 that of the first reflective polarizing film layer 3.

In this embodiment, the structure, the setting position, the working principle, etc. of the display module, the backlight module, the polarizing layer and the under-screen optical fingerprint recognition device have been described in detail in the first embodiment, and are not described here again.

In the liquid crystal display screen supporting the fingerprint identification function under the screen provided by the embodiment, the detection light source is located between the diffuse reflection layer and the second reflection type polarized light film layer, and the polarization direction of the second reflection type polarized light film layer is the same as that of the first reflection type polarized light film layer, when the detection light source irradiates on the second reflection type polarized light film layer, about 50% of P waves pass through, and the rest 50% of S waves are continuously converted through the second reflection type polarized light film layer and the diffuse reflection film layer, so that most of natural light emitted by the detection light source can be converted into P wave polarized light, generally, the conversion rate of 80% can be achieved, namely, the intensity of finally generated reflected S waves is about 20%, compared with the condition that 50% of reflected S waves are generated in the prior art, the quantity of reflected light is greatly reduced, the degree of imaging interference of the reflected light on fingerprint images is reduced, and the fingerprint identification accuracy of the optical fingerprint identification device under the screen is improved.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the application.

Claims

1. An under-screen optical fingerprint identification device is suitable for a liquid crystal display screen 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 comprises: the optical fingerprint sensor comprises an optical sensing array with a plurality of sensing units; the detection light source is used for emitting detection light, the detection light irradiates the finger through the liquid crystal display screen, and the light path guiding structure is used for guiding the fingerprint detection light which is reflected by the finger, carries fingerprint information and penetrates through the liquid crystal display screen to the optical fingerprint sensor; the optical fingerprint sensor is used for acquiring fingerprint information of the finger according to the fingerprint detection light; at least one of the detection light and the fingerprint detection light penetrates through a polarizing layer, the polarizing layer is used for filtering S waves in the detection light and/or the fingerprint detection light, and the polarizing layer is positioned above the under-screen optical fingerprint identification device;

2. The under-screen optical fingerprint recognition device according to claim 1, wherein the polarizing layer is disposed on a light-emitting surface of the backlight module, or disposed on a back surface of the backlight module facing away from the light-emitting surface, or disposed in the backlight module.

3. The device of claim 2, 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.

4. An off-screen optical fingerprint recognition device according to claim 3, wherein the polarizing layer is located at least above the detection light source so that the detection light is irradiated onto the finger through the polarizing layer and the liquid crystal display;

and a first light through hole is arranged at the position of the backboard component corresponding to the detection light source, and the polarization layer above the detection light source at least covers the first light through hole.

5. An off-screen optical fingerprint recognition device according to claim 3 or 4, wherein the polarizing layer is located at least above the light path guiding structure such that the fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

And a second light through hole is arranged at the position of the backboard component corresponding to the light path guiding structure, and the polarizing layer at least covers the second light through hole.

6. The off-screen optical fingerprint recognition device of claim 5, wherein the light path guiding structure comprises an optical lens layer comprising one or more aspheric lenses for converging the fingerprint detection light onto the optical fingerprint sensor, and a polarizing layer over the light path guiding structure covers at least a field of view of the optical lens layer.

7. The device of claim 4, further comprising a second reflective polarizing film layer and a diffuse reflective layer,

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 positioned 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 that of the first reflective polarizing film layer.

8. The under-screen optical fingerprint recognition device of claim 7, wherein 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.

9. The under-screen optical fingerprint recognition device according to claim 7, further comprising a flexible circuit board FPC, wherein the detection light source is disposed on the flexible circuit board FPC, and the diffuse reflection layer is disposed on a face of the flexible circuit board FPC facing the detection light source.

10. The under-screen optical fingerprint recognition device according to claim 7, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.

11. The under-screen optical fingerprint recognition device according to any one of claims 1-4, wherein the detection light source, the light path guiding structure, and the optical fingerprint sensor are disposed on a center frame of the liquid crystal display.

12. An off-screen optical fingerprint identification system, comprising a liquid crystal display screen and the off-screen optical fingerprint identification device according to any one of claims 1-11, wherein the off-screen optical fingerprint identification device is arranged below the liquid crystal display screen and is used for detecting fingerprint information of a finger above the liquid crystal display screen.

13. The system of claim 12, wherein the polarizing layer in the liquid crystal display is disposed on a light exit surface of the backlight module, or on a back surface of the backlight module facing away from the light exit surface, or in the backlight module.

14. The system of claim 13, 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.

15. The system of claim 14, wherein the polarizing layer is positioned at least above the detection light source such that the detection light impinges on the finger through the polarizing layer and the liquid crystal display;

16. An off-screen optical fingerprint recognition system according to claim 14 or 15, wherein the polarizing layer is located at least above the light path guiding structure such that the fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

17. The off-screen optical fingerprint recognition system of claim 16, wherein the light path directing structure comprises an optical lens layer comprising one or more aspheric lenses for focusing the fingerprint detection light onto the optical fingerprint sensor, a polarizing layer over the light path directing structure covering at least a field of view of the optical lens layer.

18. The system of claim 15, further comprising a second reflective polarizing film layer and a diffuse reflective layer,

19. The under-screen optical fingerprint recognition 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 covers at least the first light passing aperture.

20. The under-screen optical fingerprint recognition system of claim 18, further comprising a flexible circuit board FPC, wherein the detection light source is disposed on the flexible circuit board FPC, and wherein the diffuse reflection layer is disposed on a side of the flexible circuit board FPC facing the detection light source.

21. The under-screen optical fingerprint recognition system of claim 18, wherein the diffuse reflecting layer is a white ink layer or a silver powder layer.

22. The system of any of claims 12-15, wherein the detection light source, the light path guiding structure, and the optical fingerprint sensor are disposed on a center frame of the liquid crystal display.

23. An lcd screen supporting an on-screen fingerprint recognition function, below which an on-screen optical fingerprint recognition device according to any one of claims 1 to 11 is disposed, comprising: the display module, the backlight module and the first reflective polarizing film layer are positioned between the display module and the backlight module;

24. The lcd of claim 23, wherein the polarizing layer is disposed on a light exit surface of the backlight module, or on a back surface of the backlight module facing away from the light exit surface, or within the backlight module.

25. The lcd 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.

26. The lcd panel of claim 25, wherein the polarizing layer is positioned at least above the detection light source such that the detection light is transmitted through the polarizing layer and the lcd panel to the finger;

27. The lcd screen of claim 25 or 26, wherein the polarizing layer is positioned at least above the light path guiding structure such that the fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

28. The liquid crystal display of claim 27, wherein the light path directing structure comprises an optical lens layer comprising one or more aspheric lenses for focusing the fingerprint detection light onto the optical fingerprint sensor, and wherein a polarizing layer over the light path directing structure covers at least a field of view of the optical lens layer.

29. The liquid crystal display of claim 26, wherein a second reflective polarizing film layer and a diffuse reflective layer are further provided,

30. The lcd of claim 29, wherein 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.

31. The liquid crystal display of claim 29, further comprising a flexible circuit board FPC, wherein the detection light source is disposed on the flexible circuit board FPC, and wherein the diffuse reflection layer is disposed on a side of the flexible circuit board FPC facing the detection light source.

32. The liquid crystal display according to claim 29, wherein the diffuse reflection layer is a white ink layer or a silver powder layer.

33. The liquid crystal display of any one of claims 23-26, wherein the detection light source, the light path guiding structure, and the optical fingerprint sensor are disposed on a center frame of the liquid crystal display.

34. An under-screen optical fingerprint identification device is suitable for a liquid crystal display screen 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 comprises: the optical fingerprint sensor comprises an optical sensing array with a plurality of sensing units; the detection light source is used for emitting detection light, part of the detection light irradiates the finger through the second reflection type polarized light film layer, part of the detection light irradiates the diffuse reflection layer after being reflected by the second reflection type polarized light film layer, so that part of the light after diffuse reflection irradiates the finger through the second reflection type polarized light film layer, and the light path guiding structure is used for guiding the fingerprint detection light which is reflected by the finger, carries fingerprint information and penetrates through the liquid crystal display to the optical fingerprint sensor; the optical fingerprint sensor is used for acquiring 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 positioned between the diffuse reflection layer and the second reflective polarizing film layer;

35. The device of claim 34, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, a first light hole is formed in a position of the back plate assembly corresponding to the detection light source, 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 light hole.

36. The device according to claim 35, further comprising a polarizing layer, wherein at least one of the probe light and the fingerprint detection light is transmitted through the polarizing layer, the polarizing layer is used for filtering S-waves in the probe light and/or the fingerprint detection light, and the polarizing layer is located above the device;

37. The device of claim 36, wherein the polarizing layer is disposed on a light exit surface of the backlight module, or on a back surface of the backlight module facing away from the light exit surface, or in the backlight module.

38. The device of claim 37, wherein the polarizing layer is disposed on the back plate assembly, and the second reflective polarizing film layer is disposed between the polarizing layer and the detection light source such that the detection light passes through the second reflective polarizing film layer, the polarizing layer, and the liquid crystal display to illuminate the finger.

39. The device of claim 38, wherein a fourth fixing groove is formed in a side of the back plate component facing away from the light guide plate, and the polarizing layer and the second reflective polarizing film layer are sequentially stacked in the fourth fixing groove.

40. An off-screen optical fingerprint recognition device according to claim 37 or 38, wherein the polarizing layer is provided on the back plate assembly, the polarizing layer being located at least above the light path guiding structure such that the fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

41. An off-screen optical fingerprint recognition apparatus according to claim 40, wherein the light path directing structure comprises an optical lens layer comprising one or more aspheric lenses for focusing the fingerprint detection light onto the optical fingerprint sensor, a polarizing layer over the light path directing structure covering at least a field of view of the optical lens layer.

42. The under-screen optical fingerprint recognition device according to any one of claims 34-38, further comprising a flexible circuit board FPC, wherein the detection light source is disposed on the flexible circuit board FPC, and wherein the diffuse reflection layer is disposed on a side of the flexible circuit board FPC facing the detection light source.

43. An under-screen optical fingerprint recognition device according to any one of claims 34-38, wherein the diffuse reflecting layer is a white ink layer or a silver powder layer.

44. An off-screen optical fingerprint recognition device according to any one of claims 34-38, wherein the detection light source, the light path guiding structure and the optical fingerprint sensor are provided on a center frame of the liquid crystal display.

45. An off-screen optical fingerprint identification system comprising a liquid crystal display and an off-screen optical fingerprint identification device as claimed in any one of claims 34 to 44, the off-screen optical fingerprint identification device being disposed below the liquid crystal display for detecting fingerprint information of a finger above the liquid crystal display.

46. The system of claim 45, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, a first light hole is formed in a position, corresponding to the detection light source, of the back plate assembly, 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 hole.

47. The system of claim 46, further comprising a polarizing layer, wherein at least one of the probe light and the fingerprint detection light is transmitted through the polarizing layer, the polarizing layer is configured to filter S-waves in the probe light and/or the fingerprint detection light, and the polarizing layer is located above the device;

48. The system of claim 47, wherein the polarizing layer is disposed on a light exit surface of the backlight module, or on a back surface of the backlight module facing away from the light exit surface, or within the backlight module.

49. An off-screen optical fingerprint recognition system according to claim 48, wherein the polarizing layer is disposed on the back plate assembly, and a second reflective polarizing film layer in the liquid crystal display is disposed between the polarizing layer and the detection light source, such that a portion of the detection light passes through the second reflective polarizing film layer, the polarizing layer, and the liquid crystal display to illuminate the finger.

50. An under-screen optical fingerprint recognition system according to claim 49, wherein a fourth fixing groove is formed in a side of the back plate component facing away from the light guide plate, and the polarizing layer and the second reflective polarizing film layer are sequentially laminated in the fourth fixing groove.

51. An off-screen optical fingerprint recognition system according to claim 48 or 49, wherein the polarizing layer is provided on the backplate assembly, the polarizing layer being located at least above the light path guiding structure such that the fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

52. The off-screen optical fingerprint recognition system of claim 51, wherein the light path directing structure comprises an optical lens layer including one or more aspheric lenses for focusing the fingerprint detection light onto the optical fingerprint sensor, a polarizing layer over the light path directing structure covering at least a field of view of the optical lens layer.

53. The system of any one of claims 45-49, further comprising a flexible circuit board FPC, wherein the detection light source is disposed on the flexible circuit board FPC, and wherein the diffuse reflection layer in the liquid crystal display is disposed on a side of the flexible circuit board FPC facing the detection light source.

54. An under-screen optical fingerprint recognition system according to any one of claims 45-49, wherein the diffuse reflecting layer is a white ink layer or a silver powder layer.

55. An off-screen optical fingerprint recognition system according to any one of claims 45-49, wherein the detection light source, the light path guiding structure and the optical fingerprint sensor are disposed on a center frame of the liquid crystal display.

56. An lcd screen supporting an on-screen fingerprint recognition function, below which is provided an on-screen optical fingerprint recognition device according to any one of claims 34 to 44, comprising: the display module, the backlight module and the first reflective polarizing film layer are positioned between the display module and the backlight module;

57. The liquid crystal display of claim 56, wherein the backlight module comprises a back plate assembly for fixing the light guide plate, a first light through hole is formed in a position, corresponding to the detection light source, of the back plate assembly, 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.

58. The liquid crystal display of claim 57, further comprising a polarizing layer, wherein at least one of the probe light and the fingerprint detection light is transmitted through the polarizing layer, the polarizing layer is used to filter S-waves in the probe light and/or the fingerprint detection light, and the polarizing layer is located above the under-screen optical fingerprint recognition device;

59. The liquid crystal display of claim 58, wherein the polarizing layer is disposed on a light exit surface of the backlight module, or on a back surface of the backlight module facing away from the light exit surface, or within the backlight module.

60. A liquid crystal display according to claim 59 wherein the polarizing layer is disposed on the back plate assembly and the second reflective polarizing film layer is disposed between the polarizing layer and the detection light source such that the detection light passes through the second reflective polarizing film layer, the polarizing layer, and the liquid crystal display to illuminate the finger.

61. The lcd of claim 60, wherein the back plate assembly has a fourth fixing groove formed at a side facing away from the light guide plate, and the polarizing layer and the second reflective polarizing film layer are sequentially laminated in the fourth fixing groove.

62. A liquid crystal display according to claim 59 or 60, wherein the polarizing layer is provided on the back plate assembly, the polarizing layer being located at least above the light path guiding structure such that the fingerprint detection light is incident into the light path guiding structure through the polarizing layer;

63. The liquid crystal display of claim 62, wherein the light path directing structure comprises an optical lens layer comprising one or more aspheric lenses for focusing the fingerprint detection light onto the optical fingerprint sensor, and a polarizing layer over the light path directing structure covers at least a field of view of the optical lens layer.

64. The lcd screen of any one of claims 56-60, further comprising a flexible circuit board FPC, wherein the detection light source is disposed on the flexible circuit board FPC, and wherein the diffuse reflection layer is disposed on a side of the flexible circuit board FPC facing the detection light source.

65. The lcd of any one of claims 56-60, wherein the diffuse reflective layer is a white ink layer or a silver powder layer.

66. The lcd of any one of claims 56-60, wherein the detection light source, the light path guiding structure, and the optical fingerprint sensor are disposed on a center frame of the lcd.