Fingerprint identification device and electronic equipment

Abstract

The embodiment of the utility model provides a fingerprint identification device and electronic equipment. The fingerprint identification device comprises an optical fingerprint sensor and a screen, and the screen is arranged above the optical fingerprint sensor; a light-emitting layer, a 1 / 4 wave plate and a linear polarizer are arranged in the screen; the light-emitting layer is used for emitting light signals; the 1 / 4 wave plate is arranged above the light-emitting layer; the linear polarizing film is arranged above the 1 / 4 wave plate and emits linear polarized light based on an optical signal emitted by the light-emitting layer; the fingerprint identification device further comprises a depolarization layer, and the depolarization layer is arranged above the linear polarizer and used for converting the linearly polarized light emitted from the linear polarizer into non-polarized light. Through adding the depolarization layer, on the basis of realizing optical fingerprint identification, emission of screen natural light is realized, screen reflected light of the electronic equipment is inhibited, and a fingerprint identification function and a screen eye protection function are realized at the same time.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of electronic devices, and in particular to a fingerprint identification device and an electronic device. BACKGROUND

[0002] With the advent of the era of full-screen mobile phones, the application of fingerprint identification devices arranged under or in the screen in electronic devices such as mobile phones has been widely developed. Fingerprint identification has various modes, such as capacitive fingerprint identification, ultrasonic fingerprint identification, optical fingerprint identification, etc. In the process of optical fingerprint identification, the fingerprint identification device emits light to the finger and receives reflected light with fingerprint information reflected by the finger, based on which a fingerprint image is constructed to identify the fingerprint.

[0003] Recently, mobile terminal users have put forward higher requirements for screen eye protection on the basis of realizing fingerprint identification. Some studies have shown that circularly polarized light or natural light can play a role in eye protection compared to linearly polarized light. Therefore, circularly polarized screens have become a new trend, and how to ensure the fingerprint identification function of the fingerprint identification device and the screen eye protection requirement need to be solved urgently. CONTENT OF THE UTILITY MODEL

[0004] Therefore, embodiments of the present application provide a fingerprint identification device and an electronic device, which simultaneously realize the functions of fingerprint identification and screen eye protection.

[0005] According to a first aspect of embodiments of the present application, a fingerprint identification device is provided, comprising: an optical fingerprint sensor and a screen, the screen being arranged above the optical fingerprint sensor, the screen internally being provided with a light-emitting layer, a 1 / 4 wave plate and a linear polarizer; wherein the light-emitting layer is used to emit light signals; the 1 / 4 wave plate is arranged above the light-emitting layer; the linear polarizer is arranged above the 1 / 4 wave plate, based on which linearly polarized light is emitted; the fingerprint identification device further comprises a depolarization layer, the depolarization layer being arranged above the linear polarizer and being used to convert the linearly polarized light emitted from the linear polarizer into unpolarized light.

[0006] Optionally, in an implementation manner, the depolarization layer is arranged in the screen and above the linear polarizer.

[0007] Optionally, in an implementation manner, a bonding adhesive layer is arranged between the depolarization layer and the linear polarizer.

[0008] Optionally, in an implementation manner, the screen further comprises a cover plate, the cover plate being arranged at the uppermost layer of the screen, and the depolarization layer being above the cover plate.

[0009] Optionally, in an implementation manner, the depolarization layer is bonded above the cover plate.

[0010] Optionally, in an implementation form, the material of the depolarization layer is polyethylene terephthalate (PET) or polyimide (PI).

[0011] Optionally, in an implementation form, an angle between the polarization direction of the depolarization layer and the polarization direction of the linear polarizer is within a range of (45°-a, 45°+a) or (135°-a, 135°+a), where a represents a preset error angle.

[0012] Optionally, in an implementation form, the polarization direction of the depolarization layer is parallel or perpendicular to an edge of the screen, and an angle between the polarization direction of the linear polarizer and the edge of the screen is within a range of (45°-a, 45°+a).

[0013] Optionally, in an implementation form, an angle between the polarization direction of the depolarization layer and the edge of the screen is within a range of (45°-a, 45°+a), and the polarization direction of the linear polarizer is parallel or perpendicular to the edge of the screen.

[0014] Optionally, in an implementation form, the preset error angle a is less than or equal to 5°.

[0015] Optionally, in an implementation form, the preset error angle a is less than or equal to 3°.

[0016] According to a second aspect of the embodiments of the present application, an electronic device is provided, including the fingerprint identification apparatus provided by the first aspect of the present application.

[0017] The fingerprint identification apparatus provided by the embodiments of the present application includes, from bottom to top, an optical fingerprint sensor, a light-emitting layer, a 1 / 4 wave plate, a linear polarizer, and a depolarization layer. The light-emitting layer is used for emitting light signals, and the light signals form linearly polarized light after passing through the 1 / 4 wave plate and the linear polarizer. The depolarization layer is used for converting the linearly polarized light emitted from the linear polarizer into non-polarized light. By adding the depolarization layer, the emission of natural light of the screen is realized when the fingerprint identification function is implemented, and the reflection of the screen of the electronic device is also inhibited, and the fingerprint identification function and the screen eye protection function are realized at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the embodiments of the present application, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0019] Figure 1 A scene schematic diagram of the under-screen optical fingerprint identification applicable to the embodiments of the present application;

[0020] Figure 2 A structural schematic diagram of a fingerprint identification device provided by the related art;

[0021] Figure 3 For Figure 2 A light path diagram in which light rays exit the fingerprint identification device;

[0022] Figure 4 For Figure 2 A light path diagram in which light rays enter the fingerprint identification device;

[0023] Figure 5 Another structural schematic diagram of a fingerprint identification device provided by the related art;

[0024] Figure 6 For Figure 5 A light path diagram in which light rays enter the fingerprint identification device;

[0025] Figure 7 For Figure 5 A light path diagram in which light rays exit the fingerprint identification device;

[0026] Figure 8 A structural schematic diagram of a fingerprint identification device provided by an embodiment of the present application;

[0027] Figure 9 For Figure 8 A light path diagram in which light rays exit the fingerprint identification device;

[0028] Figure 10 For Figure 8 A light path diagram in which light rays enter the fingerprint identification device;

[0029] Figure 11 Another structural schematic diagram of a fingerprint identification device provided by an embodiment of the present application;

[0030] Figure 12 A schematic diagram of a polarization direction of a depolarization layer in a fingerprint identification device provided by an embodiment of the present application;

[0031] Figure 13 A schematic diagram of a polarization direction of a linear polarizer in a fingerprint identification device provided by an embodiment of the present application;

[0032] Figure 14 A structural schematic diagram of an electronic device provided by an embodiment of the present application.

[0033] Explanation of reference numerals:

[0034] 20: optical fingerprint sensor 21: back plate

[0035] 22: light emitting layer 23: sealing layer

[0036] 24: adhesive layer 25: 1 / 4 wave plate

[0037] 26: linear polarizer 27: adhesive layer

[0038] 28: cover plate 29: depolarization layer

[0039] 251: 1 / 4 wave plate 252: 1 / 4 wave plate

[0040] 100: fingerprint recognition device 200: electronic device

[0041] 201: fingerprint recognition area 202: screen DETAILED DESCRIPTION

[0042] In order to make the personnel in the art better understand the technical solutions in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the embodiments of the present application shall fall within the scope of protection of the embodiments of the present application.

[0043] In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "right-handed", "left-handed" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0044] The embodiments of the present application provide an optical fingerprint recognition device, which can be applied to an electronic device. The embodiments of the present application are also applicable to other devices or systems using optical fingerprint recognition devices, etc.

[0045] As a common application scenario, the fingerprint recognition device provided by the embodiments of the present application can be applied to a smart phone, a tablet computer and other mobile terminals or other electronic devices having a screen, which is also called a display screen. More specifically, in the above-mentioned electronic device, the fingerprint recognition device can be specifically an optical fingerprint device, which can be arranged in a local area or an entire area below the screen, thereby forming an under-display optical fingerprint system. Alternatively, the fingerprint recognition device can also be partially or entirely integrated into the inside of the screen of the electronic device, thereby forming an in-display optical fingerprint system.

[0046] For the convenience of understanding the present application, first, the related concepts are explained.

[0047] 1. Under-screen optical fingerprint identification technology

[0048] The under-screen optical fingerprint identification technology realizes fingerprint identification by embedding an optical sensor under the screen.

[0049] Exemplary, Figure 1 A schematic diagram of one scenario of the under-screen optical fingerprint identification applicable to the embodiments of the present application. As Figure 1 shown, the electronic device 200 is a mobile phone, and the screen of the mobile phone has a fingerprint identification area 201, and a fingerprint identification device (not shown) is arranged below the screen, which includes an optical sensor (not shown). When the user places a finger in the fingerprint identification area 201 in the screen, the light emitted by the optical sensor will penetrate the screen and irradiate the skin surface of the finger. Due to the unevenness of the fingerprint texture, the intensity of the reflected light after the emitted light is reflected by the finger will be different, forming different reflection patterns. The optical sensor will reconstruct the user's fingerprint image according to the reflection pattern, and compare it with the pre-stored fingerprint image in the mobile phone to realize fingerprint identification.

[0050] 2. Polarizer (POL), polarized light

[0051] The full name of the polarizer is a polarized light sheet, which is an optical element that converts natural light into polarized light. Light is a transverse wave, which means that the vibration direction of the particle is perpendicular to the propagation direction of the wave. The intensity of the light wave in each direction perpendicular to the propagation direction of the natural light is the same. Natural light forms polarized light after passing through the polarizer. Polarization refers to the phenomenon that the vibration vector of the transverse wave is inclined to a certain direction, and the vibration vector is also called the light vector or the electric field vector. Both the polarizer and the polarized light have a polarization direction, which refers to the vibration direction of the light vector.

[0052] Polarized light includes linearly polarized light, circularly polarized light, and elliptically polarized light. Polarizers include linear polarizers, circular polarizers, and elliptical polarizers.

[0053] Linearly polarized light, also known as plane polarized light, has light vectors vibrating in a fixed direction in the direction of light propagation. The plane formed by the direction of the light vector and the direction of light propagation is called the vibration plane. The vibration plane of linearly polarized light is fixed and does not rotate. Linearly polarized light includes horizontally polarized light and vertically polarized light, with the light vector of horizontally polarized light parallel to the horizontal direction and the light vector of vertically polarized light perpendicular to the horizontal direction. Natural light forms linearly polarized light after passing through a linear polarizer.

[0054] Circularly polarized light, the vibration direction of light changes in a circular trajectory during propagation, the vibration direction of light is different at each time, but overall forms a circular trajectory. Natural light forms circularly polarized light after passing through a circular polarizer.

[0055] Elliptical polarized light, the vibration direction of light changes in an elliptical trajectory during propagation, the vibration direction of light is different at each time, but overall forms an elliptical trajectory. Natural light forms elliptical polarized light after passing through an elliptical polarizer.

[0056] Circularly polarized light includes left-handed circularly polarized light and right-handed circularly polarized light. Elliptical polarized light includes left-handed elliptical polarized light and right-handed elliptical polarized light. Among them, left-handed and right-handed refer to clockwise rotation of light vector when looking against the direction of light, and counterclockwise rotation of light vector is called left-handed.

[0057] 3, wave plate, half wave plate, 1 / 4 wave plate

[0058] Wave plate is an optical element that changes the polarization state of light by changing the phase difference of incident light.

[0059] Half wave plate can decompose linearly polarized light into two directionally polarized light and realize half wave loss of wavelength difference for the two light. In the half wave plate, the polarization angle of light in one direction is 0 degrees, and the polarization angle in the other direction is 90 degrees.

[0060] 1 / 4 wave plate, also known as quarter wave plate, can change linearly polarized light into circularly polarized light or elliptically polarized light, or change circularly polarized light or elliptically polarized light into linearly polarized light. When linearly polarized light is vertically incident on the quarter wave plate, the outgoing light forms elliptical polarized light. When the polarization direction of incident light is 45° to the wave plate optical axis, the outgoing light is circularly polarized light.

[0061] 4, depolarization

[0062] Depolarization refers to the process of converting polarized light into non-polarized light, converting light with a specific polarization direction into light without a fixed polarization direction, thereby eliminating the polarization characteristics of light.

[0063] Depolarization optical elements are usually used to realize the depolarization of light, and polarized light forms non-polarized light after passing through the depolarization optical element.

[0064] The following will be combined Figures 2-4 , the structure and working principle of the optical fingerprint identification device are exemplarily explained.

[0065] It should be noted that in this application, display screen and screen have the same meaning.

[0066] Figure 2 A structure diagram of a fingerprint identification device provided by the related art is shown in FIG. 1. Figure 2As shown, the fingerprint recognition device comprises:

[0067] The optical fingerprint sensor 20 and the screen 202. Among them, the screen 202 is provided with a back plate 21, a light emitting layer 22, a sealing layer 23, a bonding adhesive layer 24, a 1 / 4 wave plate 25, a linear polarizer 26, a bonding adhesive layer 27 and a cover plate 28.

[0068] The back plate 21 is arranged above the optical fingerprint sensor 20;

[0069] The light emitting layer 22 is arranged above the back plate 21, and the light emitting layer 22 is used for emitting light signals;

[0070] The sealing layer 23 is arranged above the light emitting layer 22;

[0071] The bonding adhesive layer 24 is arranged above the sealing layer 23;

[0072] The 1 / 4 wave plate 25 is arranged above the bonding adhesive layer 24;

[0073] The linear polarizer 26 is arranged above the 1 / 4 wave plate 25;

[0074] The bonding adhesive layer 27 is arranged above the linear polarizer 26;

[0075] The cover plate 28 is arranged above the bonding adhesive layer 27.

[0076] In structure, the back plate 21, the sealing layer 23, the bonding adhesive layer 24, the bonding adhesive layer 27 and the cover plate 28 provide protection, bearing, sealing, dust blocking and other functions for the fingerprint recognition device.

[0077] The materials, sizes (such as thickness) of the back plate 21, the sealing layer 23, the bonding adhesive layer 24, the bonding adhesive layer 27 and the cover plate 28 are not limited in the application. For example, the cover plate 28 can be a glass cover plate or a sapphire cover plate, which is located at the top of the screen of the electronic device and covers the front of the electronic device.

[0078] The 1 / 4 wave plate 25 and the linear polarizer 26 included in the fingerprint recognition device are used to change the polarization state of light.

[0079] The working principle of the fingerprint recognition device is as follows:

[0080] As shown in Figure 3 The light path direction is the light emitted from the fingerprint recognition device, which is used to realize the fingerprint recognition function.

[0081] In the outgoing light path: the light-emitting layer 22 emits a light signal, which is natural light. The natural light exiting after passing through the quarter-wave plate 25 is also natural light. The natural light exiting from the quarter-wave plate 25 is converted into linearly polarized light after passing through the linear polarizer 26. For example, if the linear polarizer 26 is a horizontal linear polarizer 26, then the light exiting from the linear polarizer 26 is horizontally linearly polarized light. The horizontally linearly polarized light is reflected from the surface of the cover plate 28, and the reflected light is also horizontally linearly polarized light.

[0082] In the reflected light path: the horizontally linearly polarized light reflected from the surface of the cover plate 28 can pass through the linear polarizer 26. The horizontally linearly polarized light passing through the linear polarizer 26 passes through the quarter-wave plate 25 and then exits as right-hand circularly polarized light, which finally reaches the optical fingerprint sensor 20.

[0083] An optical fingerprint sensor, also known as an optical fingerprint chip, sensor, sensor chip, or chip, receives reflected light, converts it into an electrical signal (i.e., a fingerprint recognition signal), and determines a fingerprint image based on this signal. Electronic devices pre-store the user's fingerprints; by comparing the fingerprint image determined by the optical fingerprint sensor 20 with the pre-stored fingerprint images in the electronic device, optical fingerprint recognition can be achieved.

[0084] like Figure 4 As shown, the light path direction is from outside the screen into the fingerprint recognition device, which is used to realize the screen eye protection function.

[0085] In the incident light path: Natural light from outside the electronic device enters the screen and is converted into linearly polarized light by the linear polarizer 26. For example, if the linear polarizer 26 is a horizontal linear polarizer 26, then the light emitted from the linear polarizer 26 is horizontally linearly polarized light. The horizontally linearly polarized light emitted from the linear polarizer 26 is then converted into right-hand circularly polarized light after passing through the quarter-wave plate 25. The right-hand circularly polarized light emitted from the quarter-wave plate 25 is converted into left-hand circularly polarized light after being reflected by the metal of the light-emitting layer 22.

[0086] In the reflected light path: the left-handed circularly polarized light reflected by the metal of the light-emitting layer 22 is transformed into vertically linearly polarized light after passing through the quarter-wave plate 25. The vertically linearly polarized light exiting from the quarter-wave plate 25 cannot pass through the linear polarizer 26 (horizontal linear polarizer).

[0087] As can be seen, natural light incident on the screen from outside the electronic device cannot pass through the linear polarizer 26 after the polarization state of the light is changed by the linear polarizer 26 and the quarter-wave plate 25. That is, the natural light incident on the screen is reflected and ultimately cannot exit the screen, thereby achieving the effect of suppressing screen reflection and protecting the user's eyes.

[0088] It should be noted that the description of the linear polarizer 26 as a horizontal linear polarizer is merely an example and does not limit the polarization direction of the linear polarizer.

[0089] Recently, mobile phone users have placed higher demands on screen eye protection. Some studies have shown that, compared to linearly polarized light, circularly polarized light or natural light can have a protective effect on the eyes. For example, ... Figure 3 As shown, when implementing the fingerprint recognition function, the light emitted from the screen in the light path of the light emitted from the fingerprint recognition device is horizontally polarized light, which is considered to have poor eye protection effect.

[0090] To meet higher eye protection requirements, Figures 5-7 Another implementation of a fingerprint recognition device provided for related technologies. For example... Figure 5 As shown, the fingerprint recognition device includes:

[0091] An optical fingerprint sensor 20 and a screen 202 are provided. The screen 202 includes a back plate 21, a light-emitting layer 22, a sealing layer 23, an adhesive layer 24, a quarter-wave plate 251, a linear polarizer 26, a quarter-wave plate 252, an adhesive layer 27, and a cover plate 28.

[0092] The back panel 21 is positioned above the optical fingerprint sensor 20;

[0093] The light-emitting layer 22 is disposed above the back plate 21, and the light-emitting layer 22 is used to emit light signals;

[0094] A sealing layer 23 is disposed above the light-emitting layer 22;

[0095] Adhesive layer 24 is disposed above sealing layer 23;

[0096] A quarter-wave plate 251 is disposed above the adhesive layer 24;

[0097] A linear polarizer 26 is positioned above a quarter-wave plate 251;

[0098] A quarter-wave plate 252 is positioned above the linear polarizer 26;

[0099] Adhesive layer 27 is disposed above quarter wave plate 252;

[0100] Cover plate 28 is disposed above adhesive layer 27.

[0101] Structurally, Figure 5 and Figure 3 In comparison: Figure 3 The fingerprint recognition device shown includes a quarter-wave plate 25 and a linear polarizer 26; Figure 5 The fingerprint recognition device shown includes two quarter-wave plates and a linear polarizer 26, with the linear polarizer 26 located between the two quarter-wave plates.

[0102] The working principle of a fingerprint recognition device is as follows:

[0103] As shown in FIG. 4, the light path direction is from the screen to the fingerprint recognition device, which is used to realize the screen eye protection function. Figure 6

[0104] On the incident light path: the natural light from outside the electronic device enters the screen, and the light emitted from the 1 / 4 wave plate 252 is natural light. The natural light emitted from the 1 / 4 wave plate 252 is converted into linearly polarized light by the linear polarizer 26. For example, the linear polarizer 26 is a horizontal linear polarizer 26, and the light emitted from the linear polarizer 26 is horizontal linearly polarized light. The horizontal linearly polarized light emitted from the linear polarizer 26 is converted into right circularly polarized light after passing through the 1 / 4 wave plate 251. The circularly polarized light emitted from the 1 / 4 wave plate 251 is converted into left circularly polarized light by the light-emitting layer 22 metal reflection.

[0105] On the reflected light path: the left circularly polarized light reflected by the light-emitting layer 22 metal is converted into vertical linearly polarized light after passing through the 1 / 4 wave plate 251. The vertical linearly polarized light emitted from the 1 / 4 wave plate 251 cannot pass through the linear polarizer 26 (horizontal linear polarizer).

[0106] As can be seen, the natural light incident on the screen cannot be finally emitted from the screen after reflection, thereby achieving the effect of suppressing screen reflection and protecting the user's eyes.

[0107] As shown in FIG. 4, the light path direction is from the screen to the fingerprint recognition device, which is used to realize the screen eye protection function. Figure 7

[0108] On the incident light path: the natural light from outside the electronic device enters the screen, and the light emitted from the 1 / 4 wave plate 252 is natural light. The natural light emitted from the 1 / 4 wave plate 252 is converted into linearly polarized light by the linear polarizer 26. For example, the linear polarizer 26 is a horizontal linear polarizer 26, and the light emitted from the linear polarizer 26 is horizontal linearly polarized light. The horizontal linearly polarized light emitted from the linear polarizer 26 is converted into right circularly polarized light after passing through the 1 / 4 wave plate 252. The right circularly polarized light emitted from the 1 / 4 wave plate 252 is reflected by the surface of the cover plate 28, and the reflected light is left circularly polarized light.

[0109] On the reflected light path: the left circularly polarized light reflected by the surface of the cover plate 28 is converted into vertical linearly polarized light after passing through the 1 / 4 wave plate 252. The vertical linearly polarized light emitted from the 1 / 4 wave plate 252 cannot pass through the linear polarizer 26, and finally cannot reach the optical fingerprint sensor 20.

[0110] As can be seen, in the implementation of the fingerprint recognition function, the light emitted from the fingerprint recognition device on the light path is right circularly polarized light, and the eye protection effect is better than that of the prior art. Figure 3 ​​The structure shown exits horizontally linearly polarized light. However, in the reflected light path, the reflected light cannot reach the optical fingerprint sensor 20, and it is difficult to realize the fingerprint recognition function.

[0111] The embodiment of the present application provides a fingerprint recognition device, which comprises, from bottom to top, an optical fingerprint sensor, a light-emitting layer, a 1 / 4 wave plate, a linear polarizer and a depolarization layer. By adding the depolarization layer, the exit of natural light of the screen is realized when realizing the fingerprint recognition function, and the screen reflected light of the electronic device is also inhibited, and the fingerprint recognition function and the screen eye protection function are realized.

[0112] The technical solutions in the embodiments of the present application will be described below with reference to the drawings.

[0113] Figure 8 A structural schematic diagram of the fingerprint recognition device provided by the embodiment of the present application is shown in the figure. Figure 8 The fingerprint recognition device provided by the embodiment comprises:

[0114] The optical fingerprint sensor 20 and the screen 202. The screen 202 is provided with a light-emitting layer 22, a 1 / 4 wave plate 25 and a linear polarizer 26.

[0115] The fingerprint recognition device further comprises a depolarization layer 29.

[0116] The light-emitting layer 22 is arranged above the optical fingerprint sensor 20, and the light-emitting layer 22 is used for exiting light signals; the 1 / 4 wave plate 25 is arranged above the light-emitting layer 22;

[0117] The linear polarizer 26 is arranged above the 1 / 4 wave plate 25, and linearly polarized light is exited based on the light signals;

[0118] The depolarization layer 29 is arranged above the linear polarizer 26, and the depolarization layer 29 is used for converting the linearly polarized light exited from the linear polarizer 26 into non-polarized light.

[0119] The fingerprint recognition device provided by the embodiment is structurally provided with the 1 / 4 wave plate 25, the linear polarizer 26 and the depolarization layer 29. The 1 / 4 wave plate 25 and the linear polarizer 26 are used for changing the polarization state of light, and the depolarization layer 29 is used for converting the incident linearly polarized light into non-polarized light.

[0120] The working principle of the fingerprint recognition device will be described below by taking the linear polarizer 26 as a horizontal linear polarizer 26 as an example.

[0121] As shown in the figure, Figure 9 The light path direction is the exit of light from the fingerprint recognition device, which is used for realizing the fingerprint recognition function.

[0122] In the outgoing light path: the light-emitting layer 22 emits a light signal, which is natural light. The natural light exiting after passing through the quarter-wave plate 25 is also natural light. The natural light exiting from the quarter-wave plate 25 is converted into horizontally linearly polarized light after passing through the linear polarizer 26. The horizontally linearly polarized light exiting from the linear polarizer 26 is converted back into natural light after passing through the depolarization layer 29. The natural light exiting from the depolarization layer 29 is reflected from the surface of the cover plate 28, and the reflected light is also natural light.

[0123] In the reflected light path: the natural light reflected from the surface of the cover plate 28 remains natural light after passing through the depolarization layer 29. The natural light emitted from the depolarization layer 29 is converted into horizontally linearly polarized light after passing through the linear polarizer 26. The horizontally linearly polarized light emitted from the linear polarizer 26 is converted into right-hand circularly polarized light after passing through the quarter-wave plate 25. The right-hand circularly polarized light emitted from the quarter-wave plate 25 finally reaches the optical fingerprint sensor 20.

[0124] The optical fingerprint sensor 20 receives reflected light, converts the reflected light into an electrical signal, i.e., a fingerprint recognition signal, and determines a fingerprint image based on the fingerprint recognition signal. The electronic device pre-stores the user's fingerprint; by comparing the fingerprint image determined by the optical fingerprint sensor with the pre-stored fingerprint image in the electronic device, the optical fingerprint recognition function can be achieved.

[0125] It is evident that when implementing fingerprint recognition, the light emitted from the fingerprint recognition device onto the screen is natural light, which improves the screen's eye protection effect compared to emitted linearly polarized light.

[0126] like Figure 10 As shown, the light path direction is from outside the screen to the fingerprint recognition device, which is used to realize the screen eye protection function.

[0127] In the incident light path: Natural light from outside the electronic device enters the screen and remains natural light after passing through the depolarization layer 29. Natural light exiting the depolarization layer 29 is converted into horizontally linearly polarized light after passing through the linear polarizer 26. The horizontally linearly polarized light exiting the linear polarizer 26 is converted into right-hand circularly polarized light after passing through the quarter-wave plate 25. The right-hand circularly polarized light exiting the quarter-wave plate 25 is converted into left-hand circularly polarized light after being reflected by the metal of the light-emitting layer 22.

[0128] In the reflected light path: the left-handed circularly polarized light reflected by the metal of the light-emitting layer 22 is transformed into vertically linearly polarized light after passing through the quarter-wave plate 25. The vertically linearly polarized light exiting from the quarter-wave plate 25 cannot pass through the linear polarizer 26 (horizontal linear polarizer).

[0129] As can be seen, the natural light incident on the screen from the outside of the electronic device cannot pass through the linear polarizer 26 after the change of the polarization state of the light by the linear polarizer 26 and the 1 / 4 wave plate 25, that is, the natural light incident on the screen is finally reflected and cannot exit the screen, thereby achieving the effect of suppressing screen reflection and protecting the eyes of the user.

[0130] In summary, the fingerprint identification device provided in the embodiment includes, from bottom to top, an optical fingerprint sensor, a light-emitting layer, a 1 / 4 wave plate, a linear polarizer, and a depolarization layer. By arranging the depolarization layer, the light exiting the screen is natural light when the fingerprint identification function is implemented, which improves the screen eye protection effect on the basis of implementing the fingerprint identification function compared with the case of exiting linearly polarized light. Moreover, the fingerprint identification device provided in the embodiment also suppresses the screen reflection caused by the light incident from the outside of the screen of the electronic device, and simultaneously implements the fingerprint identification function and the screen eye protection function.

[0131] It should be noted that the fingerprint identification device can also include other hierarchical structures. Optionally, the fingerprint identification device can also include a back plate, a sealing layer, a bonding adhesive layer, and a cover plate, which can be referred to the related descriptions of the structures shown in the above Figure 2 Optionally, in one structure, as shown in the above Figure 8 The fingerprint identification device includes, from bottom to top, an optical fingerprint sensor 20, a back plate 21, a light-emitting layer 22, a sealing layer 23, a bonding adhesive layer 24, a 1 / 4 wave plate 25, a linear polarizer 26, a depolarization layer 29, a bonding adhesive layer 27, and a cover plate 28.

[0132] Optionally, in order to improve the depolarization effect of the depolarization layer on light, the material of the depolarization layer is polyethylene terephthalate (PET) or polyimide (PI).

[0133] The position of the depolarization layer 29 in the fingerprint identification device is described below.

[0134] Optionally, in one implementation, as shown in the above Figure 8 The depolarization layer 29 is arranged in the screen 202 and above the linear polarizer 26.

[0135] In this implementation, the depolarization layer is a layer structure in the hierarchical structure of the screen, the screen is referred to as a whole in the electronic device, and the possibility of damage to the depolarization layer is low, thereby increasing the service life.

[0136] Further, a bonding adhesive layer is arranged between the depolarization layer 29 and the linear polarizer 26.

[0137] In this implementation, the depolarization layer and the linear polarizer are bonded together with an adhesive layer to form a stable structure, which ensures the effect of changing the polarization state of light, reduces the possibility of damage, and increases the service life.

[0138] Optionally, in another implementation, the screen 202 also includes a cover plate 28, which is disposed on the top layer of the screen 202, and the depolarization layer 29 is located above the cover plate 28.

[0139] For example, Figure 11 This is another structural schematic diagram of the fingerprint recognition device provided in an embodiment of this application. (See attached diagram.) Figure 11 As shown, the fingerprint recognition device includes, from bottom to top: an optical fingerprint sensor 20, a back plate 21, a light-emitting layer 22, a sealing layer 23, an adhesive layer 24, a quarter-wave plate 25, a linear polarizer 26, an adhesive layer 27, a cover plate 28, and a depolarization layer 29.

[0140] In this implementation, the de-biasing layer serves as the top-level structure of the fingerprint recognition device, making it easier to repair and replace when problems occur, and allowing for more flexible setup.

[0141] Optionally, the deflection layer 29 is attached above the cover plate 28.

[0142] In this implementation, the depolarization layer can be an independent film layer that can be applied to the top of the screen cover by the user, making it easy to replace in case of problems and providing more flexible settings.

[0143] Optionally, the angle between the polarization direction of the depolarization layer 29 and the polarization direction of the linear polarizer 26 is within the range of (45°-a, 45°+a) or (135°-a, 135°+a), where a represents a preset error angle.

[0144] Specifically, when light is emitted from the fingerprint recognition device, the linear polarizer emits linearly polarized light, and the depolarization layer converts this linearly polarized light into unpolarized light. The linear polarizer has a polarization direction, which affects the polarization direction of the emitted linearly polarized light. The depolarization layer may exhibit depolarization, which refers to the change in polarization state of light after passing through a medium, resulting in a decrease in the degree of polarization.

[0145] In order to ensure that the structure of the depolarization layer combined with the linear polarizer makes the light emitted from the depolarization layer be non-polarized light, reduce the depolarization problem of the depolarization layer, the angle between the polarization direction of the depolarization layer and the polarization direction of the linear polarizer is set to 45° or 135°. However, in actual products, there is usually a small deviation in the setting of the angle, therefore, the angle deviation a is set, that is, the angle between the polarization direction of the depolarization layer and the polarization direction of the linear polarizer is within the range of (45°-a, 45°+a) or (135°-a, 135°+a), which ensures the effect that the linear polarized light emitted from the linear polarizer is converted into non-polarized light by the depolarization layer, and further improves the eye protection effect of the screen when realizing the fingerprint identification function.

[0146] It should be noted that the present embodiment does not limit the value or value range of the preset error angle a. Alternatively, the preset error angle a is less than or equal to 5°. Alternatively, the preset error angle a is less than or equal to 3°. It can be understood that, in order to improve the effect that the light emitted from the depolarization layer is non-polarized light, the smaller the value of a is, the better, and in an ideal case, it can be equal to 0.

[0147] Alternatively, in an implementation manner, the polarization direction of the depolarization layer is parallel or perpendicular to the edge of the screen, and the angle between the polarization direction of the linear polarizer and the edge of the screen is within the range of (45°-a, 45°+a) or (135°-a, 135°+a).

[0148] The screen of the electronic device is usually rectangular, and the edges of the screen include two mutually perpendicular edges. According to the length of the edges of the screen, the edges of the screen include long edges and short edges. The polarization direction of the depolarization layer is parallel or perpendicular to the edge of the screen, including that the polarization direction of the depolarization layer is parallel or perpendicular to the long edge of the screen, or the polarization direction of the depolarization layer is parallel or perpendicular to the short edge of the screen of the electronic device. Exemplarily, Figure 12 The schematic diagram of the polarization direction of the depolarization layer in the fingerprint identification device provided by the embodiments of the present application is shown. As shown in Figure 12 The polarization direction of the depolarization layer 29 is parallel or perpendicular to the edge of the screen of the electronic device 200.

[0149] Exemplarily, Figure 13 The schematic diagram of the polarization direction of the linear polarizer in the fingerprint identification device provided by the embodiments of the present application is shown. As shown in Figure 13 The angle between the polarization direction of the linear polarizer and the edge (long edge or short edge) of the screen is within the range of (45°-a, 45°+a) or (135°-a, 135°+a).

[0150] In this implementation manner, the structure of the depolarization layer combined with the linear polarizer and the angle setting reduce the depolarization problem of the depolarization layer, ensure that the light emitted from the depolarization layer is non-polarized light, and further improve the eye protection effect of the screen when realizing the fingerprint identification function.

[0151] Optionally, in another implementation, the included angle between the polarization direction of the depolarization layer and the edge of the screen is located in the range of (45°-a, 45°+a) or (135°-a, 135°+a), and the polarization direction of the linear polarizer is parallel or perpendicular to the edge of the screen.

[0152] In this implementation, the polarization direction of the linear polarizer is parallel or perpendicular to the edge (long edge or short edge) of the screen, and the included angle between the polarization direction of the depolarization layer and the polarization direction of the linear polarizer is located in the range of (45°-a, 45°+a) or (135°-a, 135°+a). The structure and angle setting of the depolarization layer combined with the linear polarizer reduce the depolarization problem of the depolarization layer, ensure that the light emitted from the depolarization layer is non-polarized light, and further improve the eye protection effect of the screen when realizing the fingerprint recognition function.

[0153] Based on the fingerprint recognition device provided in the above embodiments of the application, the application further provides an electronic device. Exemplarily, Figure 14 A structural schematic diagram of the electronic device provided in the embodiments of the application is shown in FIG. 2. As shown in FIG. 2, the electronic device 200 includes the fingerprint recognition device 100 provided in the embodiments of the application. Figure 14

[0154] Optionally, the electronic device can further include a processor, a communications interface, a memory, and a communications bus. Wherein:

[0155] The processor, the communications interface, and the memory complete mutual communication through the communications bus.

[0156] The communications interface is configured to communicate with other devices.

[0157] The processor is configured to execute the computer program.

[0158] Specifically, the computer program can include program codes including computer operation instructions.

[0159] The processor can be a CPU, or a GPU (Graphic Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the application. The one or more processors included in the smart device can be processors of the same type, such as one or more CPUs; or can be processors of different types, such as one or more CPUs and one or more ASICs.

[0160] ​a memory for storing the computer program. The memory can comprise a high speed RAM memory and can also include a non-volatile memory, such as at least one disk memory.

[0161] Those skilled in the art can understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or in a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0162] It should be understood that the various drawings of the embodiments of the present application are for the purpose of showing structures, and the size proportions of each structure are not necessarily drawn according to actual proportions.

[0163] The above method according to the embodiments of the present application can be implemented in hardware, firmware, or as software or computer code that can be stored in a recording medium such as a CD-ROM, a RAM, a floppy disk, a hard disk, or a magneto-optical disk, or be downloaded through a network and originally stored in a remote recording medium or a non-transitory machine-readable medium and then stored in a local recording medium, so that the method described herein can be stored in such software processing using a general computer, a special processor, or programmable or special hardware such as an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA). It can be understood that the computer, processor, microprocessor controller, or programmable hardware includes a storage component (for example, Random Access Memory (RAM), Read-Only Memory (ROM), flash memory, etc.) that can store or receive software or computer code, which, when accessed and executed by the computer, processor, or hardware, realizes the method described herein. In addition, when a general computer accesses the code for realizing the method shown herein, the execution of the code will convert the general computer into a special computer for executing the method shown herein.

[0164] Those skilled in the art can understand that the units and method steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software manner depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for a specific application, but such implementation should not be considered beyond the scope of the embodiments of the present application.

[0165] The above embodiments are only used to illustrate but not to limit the embodiments of the present application. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present application, and all equivalent technical solutions belong to the scope of the embodiments of the present application. The patent protection scope of the embodiments of the present application should be defined by the claims.

Claims

1. A fingerprint recognition device, comprising: An optical fingerprint sensor and a screen disposed above the optical fingerprint sensor, the screen internally provided with a light-emitting layer, a 1 / 4 wave plate and a linear polarizer; wherein The light-emitting layer is configured to emit light signals; The 1 / 4 wave plate is disposed above the light-emitting layer; The linear polarizer is disposed above the 1 / 4 wave plate and configured to emit linearly polarized light based on the light signals; The fingerprint identification device further comprises a depolarization layer disposed above the linear polarizer and configured to convert the linearly polarized light emitted from the linear polarizer into non-polarized light.

2. The fingerprint recognition apparatus of claim 1, wherein, The depolarization layer is disposed in the screen and above the linear polarizer.

3. The fingerprint recognition apparatus of claim 2, wherein, A bonding adhesive layer is disposed between the depolarization layer and the linear polarizer.

4. The fingerprint recognition apparatus of claim 1, wherein, The screen further comprises a cover plate disposed at the uppermost layer of the screen, and the depolarization layer is above the cover plate.

5. The fingerprint recognition apparatus of claim 4, wherein, The depolarization layer is bonded above the cover plate.

6. The fingerprint recognition device according to any one of claims 1-5, wherein, The depolarization layer is made of polyethylene terephthalate (PET) or polyimide (PI).

7. The fingerprint recognition device according to any one of claims 1-5, wherein, An angle between a polarization direction of the depolarization layer and a polarization direction of the linear polarizer is within a range of (45°-a, 45°+a) or (135°-a, 135°+a), where a represents a preset error angle.

8. The fingerprint recognition apparatus of claim 7, wherein, The polarization direction of the depolarization layer is parallel or perpendicular to an edge of the screen, and an angle between the polarization direction of the linear polarizer and the edge of the screen is within a range of (45°-a, 45°+a) or (135°-a, 135°+a).

9. The fingerprint recognition apparatus of claim 7, wherein, An angle between the polarization direction of the depolarization layer and the edge of the screen is within a range of (45°-a, 45°+a) or (135°-a, 135°+a), and the polarization direction of the linear polarizer is parallel or perpendicular to the edge of the screen.

10. The fingerprint recognition apparatus of claim 7, wherein, The preset error angle a is less than or equal to 5°.

11. The fingerprint recognition apparatus of claim 10, wherein, The preset error angle a is less than or equal to 3°.

12. An electronic device comprising: The fingerprint identification device according to any one of claims 1-11.

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