WO2021146955A1

WO2021146955A1 - Optical fingerprint detection apparatus, touch screen and electronic device

Info

Publication number: WO2021146955A1
Application number: PCT/CN2020/073630
Authority: WO
Inventors: 王磊; 张玮; 池文明; 王炳文
Original assignee: 深圳市汇顶科技股份有限公司
Priority date: 2020-01-21
Filing date: 2020-01-21
Publication date: 2021-07-29
Also published as: CN111837134A

Abstract

Provided are an optical fingerprint detection apparatus, a touch screen and an electronic device, which relate to the technical field of fingerprint recognition, and can improve the accuracy of fingerprint recognition when a finger is wet. The optical fingerprint detection apparatus is applied to an electronic device with a display screen, wherein the electronic device is provided with a glass cover plate. The apparatus comprises: a light-emitting assembly, wherein the light-emitting assembly comprises a fingerprint recognition light source, and the incident angle at which light emitted by the fingerprint recognition light source is incident to the upper surface of the glass cover plate is greater than or equal to the total reflection angle at which a light signal is incident to the air from the glass cover plate. The optical fingerprint detection apparatus further comprises an optical fingerprint module. Light that is generated by the fingerprint recognition light source and is incident to the glass cover plate has a first polarization direction, and a first polarizer is arranged in the display screen, wherein the polarization direction of the first polarizer is perpendicular to the first polarization direction.

Description

Optical fingerprint detection device, touch screen and electronic equipment

Technical field

This application relates to the field of fingerprint identification technology, and in particular to an optical fingerprint detection device, touch screen and electronic equipment.

Background technique

In recent years, with the continuous development of display technology, more and more electronic devices adopt under-screen fingerprint recognition to protect user privacy. When a user is operating an electronic device with fingerprint recognition function, he only needs to touch the display screen with his finger to realize authorization verification, and the operation is simple. However, the current under-screen fingerprint recognition method has poor fingerprint recognition accuracy when the finger is wet.

Summary of the invention

The embodiments of the present application provide an optical fingerprint detection device, a touch screen, and an electronic device, which can improve the accuracy of fingerprint recognition when the finger is wet.

On the one hand, an embodiment of the present application provides an optical fingerprint detection device, which is applied to an electronic device with a display screen, the electronic device has a glass cover, and the device includes:

A light-emitting component, the light-emitting component includes a fingerprint recognition light source, the fingerprint recognition light source is used to provide excitation light for fingerprint recognition, the light emitted by the fingerprint recognition light source is incident on the upper surface of the glass cover at an angle of incidence Greater than or equal to the total reflection angle of the light signal incident from the glass cover plate to the air;

The optical fingerprint detection device also includes an optical fingerprint module, which is arranged below the fingerprint detection area of the display screen, and is used to detect that the fingerprint recognition light source illuminates the finger above the fingerprint detection area and transmits from the finger And the light signal passing through the display screen;

The light generated by the fingerprint recognition light source has a first polarization direction after being incident on the glass cover, a first polarizer is arranged in the display screen, and the polarization direction of the first polarizer is perpendicular to the first polarizer. Polarization direction.

On the other hand, the embodiments of the present application also provide a touch screen, including a glass cover and a display screen arranged under the glass cover, wherein the touch screen further includes the above-mentioned optical fingerprint detection device; the fingerprint recognition light source generates After entering the glass cover plate, the light has a first polarization direction, a first polarizer is arranged in the display screen, and the polarization direction of the first polarizer is perpendicular to the first polarization direction.

In another aspect, an embodiment of the present application also provides an electronic device, including the above-mentioned optical fingerprint detection device.

In the optical fingerprint detection device, the touch screen and the electronic device in the embodiments of the present application, the fingerprint image is not generated based on the principle of reflection imaging, but is generated based on the principle of transmission. This application uses total reflection light as the light source for fingerprint identification. Since all the optical signals at the valley line are totally reflected and cannot be received by the optical fingerprint module, most of the optical signals at the ridge line are transmitted into the finger and come from the fingerprint. The ridges are transmitted through the display screen and are received by the optical fingerprint module. In this way, the optical signals returned from the ridges and valleys received by the optical fingerprint module have a higher contrast, and a better imaging effect can be obtained. Furthermore, when the finger is dipped in water, the fingerprint valley is filled with water, and the light is refracted at the interface between the water in the fingerprint valley and the glass cover. Since water has no backscattering property, the light derived from the water continues to be directed to the valley line of the finger And reflect back to the optical fingerprint recognition sensor through the valley line of the finger. As the light travels through the water, the optical path is increased and attenuation occurs. Therefore, after the finger is wet, the brightness of the finger tissue reflected from the fingerprint valley back to the optical fingerprint module and the finger tissue reflected from the fingerprint ridge back to the optical fingerprint module The brightness difference is still large, and the fingerprint valley and the fingerprint ridge still have a high light intensity contrast. The ratio of the light intensity between the two is about 1:100, which means that compared with the prior art, the fingerprint is still better when wet. It can have better imaging quality, thereby improving the accuracy of fingerprint recognition when wet. On the other hand, if the 2D image made with finger fingerprints is placed in the fingerprint recognition position, because the 2D image and the surface of the glass cover will be in overall contact or there will be no overall contact, it is impossible to distinguish between the fingerprint valley and the fingerprint ridge to achieve total reflection and refraction of light. Therefore, the fake fingerprint imaging of the 2D image does not clearly reflect the difference between the fingerprint valley and the fingerprint ridge, which reduces the probability of being recognized as a true fingerprint and improves the security. On the other hand, since the light required for fingerprint identification is provided by the light source outside the display screen, the external light source can be controlled separately, and it is not necessary to wait for the pixels in the display screen to light up through the control method of the display screen, thus saving fingerprint identification. The time can improve the speed and accuracy of fingerprint recognition. In addition, since the light generated by the fingerprint recognition light source has the first polarization direction after being incident on the glass cover, the polarization direction of the first polarizer is perpendicular to the first polarization direction, and part of the light is coupled down into the display screen, and these lights have The first polarization direction, the polarization direction of the first polarizer is perpendicular to the first polarization direction, so when the light that does not change the polarization direction reaches the first polarizer in the display, it will be blocked by the first polarizer and will not It continues to propagate downward so that it will not be coupled to the optical fingerprint recognition sensor below, which improves the problem of interference caused by light leakage from the fingerprint recognition light source to the optical fingerprint recognition sensor, thereby improving the accuracy of fingerprint recognition.

Description of the drawings

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

Fig. 1 is a schematic diagram of an under-screen fingerprint recognition state in the prior art;

Fig. 2 is a partial enlarged schematic diagram of a partial area of Fig. 1;

3 is a schematic diagram of an electronic device in a fingerprint recognition state in an embodiment of the application;

4 is a partial enlarged schematic diagram of a part of the area where light enters the glass cover in FIG. 3;

FIG. 5 is a partial enlarged schematic diagram of a part of the area in the glass cover plate at the fingerprint recognition location in FIG. 3; FIG.

Fig. 6 is a top view of the first electronic device in an embodiment of the application;

FIG. 7 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of the application;

8 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of the application;

9 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of the application;

FIG. 10 is a schematic cross-sectional structure diagram of still another electronic device in an embodiment of the application; FIG.

11 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of the application;

Fig. 12 is a top view of a second type of electronic device in an embodiment of the application;

FIG. 13 is a top view of a third electronic device in an embodiment of the application;

FIG. 14 is a top view of a fourth type of electronic device in an embodiment of the application;

15 is a top view of a fifth electronic device in an embodiment of the application;

Fig. 16 is a top view of a sixth type of electronic device in an embodiment of the application.

Detailed ways

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

The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms of "a", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

In order to more clearly illustrate the technical effects of the embodiments of the present application, before describing the embodiments of the present application, the under-screen fingerprint recognition technology in the prior art is first introduced, as shown in FIG. 1, which is the prior art. A schematic diagram of fingerprint recognition status under the screen. The electronic device includes a laminated glass cover 1'and a display screen 2'. The display screen 2'includes a light-emitting device layer 20', and the light-emitting device layer 20' is provided with a light-emitting device (Figure (Not shown in ), the light-emitting device realizes screen display by actively emitting light, and an optical fingerprint module 3'is provided under the light-emitting device layer 20' at the position of fingerprint recognition.

It should be understood that, for ease of description, the above-mentioned reflected light and scattered light are collectively referred to as reflected light. Because the ridge and valley of the fingerprint have different light reflection capabilities, the reflected light from the fingerprint ridge and the reflected light from the fingerprint valley have different light intensities. After the reflected light passes through the display screen, it is optically fingerprinted. The sensor array in the module receives and converts into the corresponding electrical signal, that is, the fingerprint detection signal; based on the fingerprint detection signal, fingerprint image data can be obtained, and fingerprint matching verification can be further performed, thereby realizing optical fingerprint recognition in the electronic device Function.

Refer also to Figure 2 for a schematic diagram based on the principle of reflected light imaging. Fingers touch the surface of the glass cover of the mobile phone during fingerprint recognition. The ridges of the fingerprints of the fingers can make good contact with the surface, and the valley lines of the fingerprints of the fingers are in good contact with the surface. A void, the void is air.

According to the law of optical refraction and reflection, when the light I irradiates the finger, the fingerprint ridge line is in good contact, and the refractive index of the finger and the glass cover is similar, so the light absorbed by the finger IT1 is more, and the reflected light IR1 is more. However, there is an air gap at the valley line. Because the refractive index difference between air and the glass cover is large, the light IT2 refracted into the finger is less, and the reflected light IR2 reflected on the surface of the glass cover is more, thus forming Based on the contrast signal between the valley and ridges of the fingerprint, the reflected signal IR2 at the valley line is stronger, while the reflected signal IR1 at the ridge line is weak, that is, the ridge line is dark and the valley line is bright, and the fingerprint sensor passes through the valley line and the ridge line. The signal difference at the location can then form a fingerprint image.

However, when the finger is wet, the valley line and the glass cover 1'are filled with water, resulting in an increase in the light transmission part of the glass cover 1'at the valley line and a decrease in the light reflection part, resulting in the valley line. The difference between the light intensity received by the ridge and the ridge is small, thus reducing the accuracy of fingerprint recognition when the fingerprint is dipped in water. On the other hand, if a 2D image made using finger fingerprints is placed in a fingerprint recognition position as a fake fingerprint, the prior art may recognize the fake fingerprint as a real fingerprint, which may bring security risks. On the other hand, the prior art uses the light-emitting device in the display screen as the light source for fingerprint collection. When performing fingerprint recognition, it is necessary to first control to light up the pixels in the fingerprint recognition area, and the light-emitting device in the driving pixel takes longer to light up. It usually takes 50-100ms, but usually the user’s finger pressing time is 150-200ms during fingerprint recognition, and only 50-150ms is used to realize fingerprint collection, so it is easy to cause inaccurate fingerprint collection, which leads to fingerprint recognition efficiency Low.

As shown in Figure 3, Figure 4, Figure 5 and Figure 6, Figure 3 is a schematic diagram of an electronic device in an embodiment of this application in a fingerprint recognition state, and Figure 4 is a partial area where light enters the glass cover in Figure 3 Fig. 5 is a partial enlarged schematic view of a part of the area in the glass cover plate of the fingerprint recognition in Fig. 3, and Fig. 6 is a top view of the first electronic device in an embodiment of the application. This application provides a An optical fingerprint detection device is applied to an electronic device with a display screen 1. The electronic device has a glass cover 2. The optical fingerprint detection device includes a light-emitting component, the light-emitting component includes a fingerprint recognition light source 3, and the fingerprint recognition light source 3 is used to provide The excitation light for fingerprint recognition, the incident angle of the light emitted by the fingerprint recognition light source 3 to the upper surface of the glass cover plate 2 is greater than or equal to the total reflection angle of the light signal from the glass cover plate 2 into the air; the optical fingerprint detection device also includes The optical fingerprint module 4 is arranged under the fingerprint detection area 10 of the display screen 1, and is used to detect the light signal that the fingerprint recognition light source 3 illuminates the finger above the fingerprint detection area 10 and transmits from the finger and passes through the display screen 1; The light generated by the identifying light source 3 has a first polarization direction after being incident on the glass cover 2. The display screen 1 is provided with a first polarizer 21, and the polarization direction of the first polarizer 21 is perpendicular to the first polarization direction.

Specifically, the structure shown in FIGS. 3 to 5 is a cross-sectional structure of an electronic device, in which the upper side of the display screen 1 is the light-emitting side, the display screen 1 is arranged under the glass cover 2, and the fingerprint recognition light source 3 is used to generate The light used for fingerprint recognition, for example, in the structure shown in FIGS. 3 to 5, in the glass cover 2, the light generated by the fingerprint recognition light source 3 enters the glass cover 2 from the lower surface of the glass cover 2 , Launch to the upper left.

Since the display screen 1 is located under the glass cover 2 and the light generated by the fingerprint identification light source 3 is in the transmission process, if the light only reaches the first polarizer 21 after being totally reflected in the glass cover 2, these The polarization direction of the light will not change and still has the first polarization direction. The polarization direction of the first polarizer 21 is perpendicular to the first polarization direction. Therefore, when the light with the first polarization direction reaches the first polarizer 21 in the display screen 1 It will be blocked by the first polarizer 21 and will not continue to propagate downward, so that it will not be coupled to the optical fingerprint module 4 below, which improves the leakage of light generated by the fingerprint recognition light source 3 to the optical fingerprint module. Group 4 causes interference problems, thereby improving the accuracy of fingerprint recognition. For the light that is generated by the fingerprint recognition light source 3 and illuminates the finger, the light will change into light with no polarization direction in the biological tissue after entering the finger, so that it can pass through the first polarizer 21 and be passed through the first polarizer 21 after returning. The optical fingerprint module 4 can ensure the normal fingerprint signal reception.

Among them, the optical fingerprint module 4 may be, for example, an optical sensor array, which can collect light returned from the finger to determine the spatial pattern and position of the fingerprint ridge and fingerprint valley, and construct the fingerprint pattern and perform fingerprint recognition, for example, as a user authentication As part of the device access process, it is compared with the stored fingerprint patterns of authorized users to determine whether the detected fingerprint is a matching fingerprint.

In the optical fingerprint detection device in the embodiment of the present application, when the first optical signal L reaches the glass cover, due to the gap between the fingerprint valley line and the glass cover, the first optical signal L is totally reflected at the valley. Since the density of fingerprints is greater than the density of air, the total reflection angle of the optical signal from the glass cover to the ridge of the finger is greater than the total reflection angle of the optical signal from the glass cover to the air. When the ridge is in contact with the glass cover, A part of the first light signal that reaches the ridge is reflected, and a part is transmitted into the ridge of the finger, and the light signal transmitted into the finger is used for fingerprint imaging.

The reflected light LR1 at the ridge line and the reflected light LR2 at the valley line will be totally reflected on the upper and lower surfaces of the glass cover, and finally attenuated. After the transmitted light LT1 at the ridge enters the finger, it is transmitted from the finger to form a first return light signal. After the first return light signal passes through the display screen, it is received by the optical fingerprint module below the display screen. The optical fingerprint module performs fingerprint identification according to the received first return light signal.

Since the light signal at the valley line is totally reflected, the fingerprint sensor can hardly receive the light signal returned at the valley line, and most of the light signal at the ridge line will be transmitted into the finger, and then transmitted from the finger by the fingerprint sensor Received, so that the fingerprint sensor can perform fingerprint recognition based on the intensity difference of the light signal at the ridge and valley.

Compared with the traditional fingerprint recognition method, this application uses transmitted light for imaging, and the contrast of the light signal at the ridges and ridges can reach 1:200. In this way, using transmitted light for imaging can obtain 5 times the traditional reflected light. The imaging signal can obtain better imaging quality, which is beneficial to improve the success rate of fingerprint recognition.

In addition, when the finger is dipped in water, the fingerprint valley is filled with water, and the light is refracted at the interface between the water in the fingerprint valley and the glass cover. Since water has no backscattering property, the light derived from the water continues to be directed to the valley line of the finger. , And reflected back to the optical fingerprint recognition sensor through the valley line of the finger. As the light travels through the water, the optical path is increased and attenuation occurs. Therefore, after the finger is wet, the brightness of the finger tissue reflected from the fingerprint valley back to the optical fingerprint module and the finger tissue reflected from the fingerprint ridge back to the optical fingerprint module The brightness difference is still large, and the fingerprint valley and the fingerprint ridge still have a high light intensity contrast. The ratio of the light intensity between the two is about 1:100, which means that compared with the prior art, the fingerprint is still better when wet. It can have better imaging quality, thereby improving the accuracy of fingerprint recognition when wet. On the other hand, if the 2D image made with finger fingerprints is placed in the fingerprint recognition position, because the 2D image and the surface of the glass cover will be in overall contact or there will be no overall contact, it is impossible to distinguish between the fingerprint valley and the fingerprint ridge to achieve total reflection and refraction of light. Therefore, the fake fingerprint imaging of the 2D image does not clearly reflect the difference between the fingerprint valley and the fingerprint ridge, which reduces the probability of being recognized as a true fingerprint and improves the security. On the other hand, since the light required for fingerprint identification is provided by the light source outside the display screen, the external light source can be controlled separately, and it is not necessary to wait for the pixels in the display screen to light up through the control method of the display screen, thus saving fingerprint identification. The time can improve the speed and accuracy of fingerprint recognition.

In addition, since the light generated by the fingerprint recognition light source and incident on the glass cover has the first polarization direction, the polarization direction of the first polarizer is perpendicular to the first polarization direction. Part of the light is coupled down into the display screen, and these lights have the first polarization direction. , The polarization direction of the first polarizer is perpendicular to the first polarization direction, so when the light that does not change the polarization direction reaches the first polarizer in the display, it will be blocked by the first polarizer and will not continue to propagate downward Therefore, it will not be coupled to the lower optical fingerprint recognition sensor, which improves the problem of interference caused by the light generated by the fingerprint recognition light source leaking to the optical fingerprint recognition sensor, thereby improving the accuracy of fingerprint recognition.

Optionally, the angle between the initial light path that the light generated by the fingerprint recognition light source 3 enters the glass cover 2 and the normal F of the plane where the glass cover 2 is located is θ, 41.8°<θ<72.4°, The normal line F of the plane where the glass cover 2 is located is the normal of the surface of the glass cover 2 away from the display screen 1. The initial light path is that the light generated by the fingerprint recognition light source 3 enters the glass cover 2 for the first time and then starts on the glass. The light path transmitted in the cover 2.

Specifically, the structure shown in FIGS. 3 to 5 is a cross-sectional structure of an electronic device, in which the upper side of the display screen 1 is the light-emitting side, the display screen 1 is arranged under the glass cover 2, and the fingerprint recognition light source 3 is used for The light for fingerprint recognition, the light generated by the fingerprint recognition light source 3 is incident obliquely into the glass cover 2 from the lower surface of the glass cover 2. For example, in the structure shown in FIGS. 3 to 5, the light generated in the glass cover 2 , The light generated by the fingerprint recognition light source 3 enters from the bottom right and emits to the top left. At this time, θ is limited to the range of 41.8°～72.4°. When the initial light of the light entering the glass cover 2 reaches the glass When covering the upper surface of the cover plate 2, the upper surface of the glass cover plate 2 is used as the incident surface, the initial light is taken as the incident light, θ is the angle between the incident light and the normal line F of the incident surface, the upper surface and the lower surface of the glass cover plate 2 Parallel, when the upper surface of the glass cover 2 is in contact with air somewhere, this position may be the area outside the finger pressing, or it may be the position of the valley line where the finger presses, where the upper surface of the glass cover 2 is glass At the interface between the two media and air, the refractive index n ₁ of the glass cover 2 is 1.5, while the refractive index n ₂ of air is 1. When light enters the medium with a lower refractive index from a medium with a higher refractive index , With a critical angle θ _a ,

The angle of incidence θ> when θ _a, so the light will be totally reflected. When the upper surface of the glass cover plate 2 touches the user's finger somewhere, that is, when the position is the position of the ridge line, the upper surface of the glass cover plate 2 at this position is the interface between the glass and the skin. The refractive index n ₁ of the plate 2 is 1.5, and the refractive index n ₃ of the skin is 1.43. When light enters a medium with a lower refractive index from a medium with a higher refractive index, it has a critical angle θ _b ,

The angle of incidence θ <θ _b, and therefore the light will refract the incident light enters the finger from the coupling ridge cover glass 2, so as to illuminate the ridge, the ridge is illuminated by light rays further cover glass 2 and The display screen 1 is transmitted to the finger optical fingerprint module 4, so that the finger optical fingerprint module 4 receives higher light intensity at the ridge line, and at the valley line, the light in the glass cover 2 will continue to pass through total reflection Propagation means that the optical fingerprint module 4 receives a lower intensity of light at the valley line, and realizes fingerprint collection by comparing the intensity of the light received at the ridge line and the valley line.

Optionally, the light generated by the fingerprint recognition light source 3 is infrared light.

Specifically, infrared light is invisible light, and the light generated by the display screen 1 itself is visible light. When the light generated by the fingerprint recognition light source 3 is infrared light, the optical fingerprint module 4 can be set to be used only for Infrared light is received, but visible light is not received. In this way, the adverse effect of visible light generated by the display screen of the display screen 1 on fingerprint recognition can be reduced.

Optionally, the wavelength of the light generated by the fingerprint recognition light source 3 is λ, 920nm<λ<960nm.

Specifically, on the one hand, the wavelength of 920nm<λ<960nm belongs to the wavelength of infrared light, which is invisible light. The light generated by the display screen 1 itself when displaying the picture is visible light. When the light generated by the fingerprint recognition light source 3 is infrared light At the same time, the optical fingerprint module 4 can be set at the same time to only receive infrared light and not to receive visible light. In this way, the visible light generated by the display screen 1 itself can reduce the adverse effect of fingerprint recognition; on the other hand, due to natural light Among them, the light intensity of 940nm wavelength is the smallest. Therefore, using 940nm light for fingerprint recognition can reduce the adverse effect of light on fingerprint recognition when natural light passes through the finger.

Optionally, the effective wavelength range of the first polarizer 21 includes the wavelength band of the light generated by the fingerprint identification light source 3 and the visible light wavelength band; the display screen 1 further includes a quarter wave plate 22, which is located at the first A polarizing plate 21 is away from the side of the glass cover plate 2.

Specifically, for example, the wavelength band of the light generated by the fingerprint recognition light source 3 is λ, and the first polarizer 21 is set to have an effective wavelength range including λ and visible light. The first polarizer 21 can be used to improve the above-mentioned light leakage problem. It can also cooperate with the lower quarter-wave plate 22 to block the visible light from the upper environment after being reflected by the display screen 1 to reduce the adverse effect on the display screen when the ambient visible light is reflected from the display screen 1.

Optionally, the first polarizer 21 has a reflectance greater than 0.8 for the light generated by the fingerprint recognition light source 3.

Specifically, for example, the wavelength band of the light generated by the fingerprint recognition light source 3 is λ, and the first polarizer 21 blocks the light with the wavelength λ and the first polarization direction while reflecting it back to the glass cover 2 for reuse. These lights, when irradiated on the finger, can further enhance the light intensity that can be obtained by the finger, thereby further improving the accuracy of fingerprint recognition.

Optionally, the first polarizer 21 is used to adhere to the surface of the glass cover plate 2 through the glue layer 20. Even if the light is reflected back to the glass cover 2 as close to the glass cover 2 as possible, the loss of light is minimized.

In the following, two specific embodiments are used to describe the situations where the fingerprint recognition light source generates natural light and polarized light.

Example one

As shown in FIG. 7 and FIG. 8, FIG. 7 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of this application, and FIG. 8 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of this application. , The light-emitting assembly further includes: a second polarizer 30, the second polarizer 30 is located between the fingerprint recognition light source 3 and the glass cover 2, so that the light generated by the fingerprint recognition light source 3 is incident on the glass cover through the second polarizer 30 2. The second polarizer 30 has the first polarization direction.

Specifically, in the first embodiment, the light generated by the fingerprint recognition light source 3 is natural light (natural light divided according to the characteristics of the polarization direction), and the natural light is a composite light including light in the first polarization direction and light in the second polarization direction. , The first polarization direction is perpendicular to the second polarization direction. By arranging the second polarizer 30 with the first polarization direction, the light in the second polarization direction cannot pass through the second polarizer 30, that is, the natural light generated by the fingerprint recognition light source 3 After passing through the second polarizer 30, it becomes polarized light having the first polarization direction, and then enters the glass cover 2. In this embodiment, the fingerprint recognition light source 3 is infrared light, the wavelength of which is λ, and 920nm<λ<960nm.

Optionally, as shown in FIG. 7, the second polarizer 30 is used to attach to the surface of the glass cover plate 2; the fingerprint recognition light source 3 is used to attach to the second polarizer 30 away from the surface of the second polarizer 30 through optical glue 5 or an optical coupler. The surface on one side of the glass cover 2.

Optionally, as shown in FIG. 8, the second polarizer 30 is used for attaching to the light-emitting surface of the fingerprint identification light source 3; the second polarizer 30 is used for attaching to the glass cover 2 through the optical glue 5 or an optical coupler. s surface.

Example two

As shown in FIG. 4, in the second embodiment, the light generated by the fingerprint recognition light source 3 has a first polarization direction.

Specifically, in the second embodiment, in the structure shown in FIG. 4, there is no need to provide a polarizer between the fingerprint recognition light source 3 and the glass cover 2, and the fingerprint recognition light source 3 can directly generate the polarization with the first polarization direction. Light.

On the basis of the first embodiment and the second embodiment, the setting method of the fingerprint recognition light source is further described below.

Optionally, the fingerprint recognition light source 3 is a vertical-cavity surface-emitting laser (Vecsel), and the light emitted by the vertical-cavity surface-emitting laser is incident on the upper surface of the glass cover plate 2 at an angle of incidence greater than or equal to the light The total reflection angle of the signal from the glass cover 2 to the air.

Specifically, when a vertical cavity surface emitting laser is used as a light source, the direction of the light generated is stronger, and the light emitting angle is more concentrated, that is, it is easier to control the light path of the light generated by it, for example, it is easier to make the light generated in the Total reflection occurs on the upper surface of the glass cover plate 2, that is, it is easier to realize that the incident angle generated on the upper surface of the glass cover plate 2 is greater than or equal to the total reflection angle from the glass cover plate 2 to the air.

Optionally, the fingerprint recognition light source 3 includes a light-emitting diode and a condensing sheet located on the light-emitting side of the light-emitting diode. The condensing sheet is used to converge the light generated by the light-emitting diodes, so that the light with the angle θ between the initial light path and the normal of the plane where the glass cover 2 is located is injected into the glass cover 2.

On the basis of the foregoing embodiments, different structures of the light-emitting assembly will be described as different embodiments in the following.

Example three

As shown in Figures 3 and 4, in the third embodiment, the light-emitting assembly further includes an optical glue 5, which is used to make the light exit surface of the fingerprint identification light source 3 adhere to the bottom of the glass cover plate 2 through the optical glue 5. Surface; the angle between the plane where the light exit surface of the fingerprint identification light source 3 is located and the lower surface of the glass cover 2 is θ, and the included angle θ is greater than or equal to the total reflection angle of the light signal from the glass cover 2 to the air; optical glue The refractive index of 5 can be 1.4 to 1.6, inclusive.

Specifically, through the arrangement of the optical glue 5, on the one hand, the fingerprint recognition light source 3 can be arranged obliquely near the lower surface of the glass cover plate 2, and on the other hand, the light exit surface of the fingerprint recognition light source 3 and the glass cover plate 2 can be set up. Fill the material with the same refractive index as the glass, so that the light path generated by the fingerprint recognition light source 3 does not change and enters the glass cover 2. The tilt of the fingerprint recognition light source 3 can be set according to the angle required by the light in the glass cover 2 angle.

Example four

As shown in FIG. 9, FIG. 9 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of the application. In the fourth embodiment, the light-emitting assembly further includes a first optical coupler 601, and the first optical coupler 601 includes a first optical coupler 601. A surface 61 and a second surface 62, the included angle between the first surface 61 and the second surface 62 is θ, the included angle θ is greater than or equal to the total reflection angle of the light signal from the glass cover 2 to the air; The first surface 61 of the coupler 601 is used for attaching to the lower surface of the glass cover 2. The first surface 61 of the first optical coupler 601 is parallel to the lower surface of the glass cover 2; the light exit surface of the fingerprint recognition light source 3 is used for It is adhered to the second surface 62 of the first optical coupler 601 by optical glue (not shown in FIG. 7), and the light exit surface of the fingerprint identification light source 3 is parallel to the second surface 62 of the first optical coupler 601; optical glue The refractive index of can be 1.4 to 1.6, including the endpoint value.

Specifically, the difference between the fourth embodiment and the third embodiment is that an optical coupler is added to couple the light of the fingerprint identification light source 3 into the glass cover 2. The first optical coupler 601 may specifically be a glass structure with a trapezoidal cross-section. The first surface 61 is attached to the lower surface of the glass cover plate 2, and the second surface 62 is attached to the light exit surface of the fingerprint identification light source 3, so that it couples the light generated from the fingerprint identification light source 3 into the glass When the cover plate 2 is installed, the light utilization rate generated by the fingerprint recognition light source 3 can be increased, so that the inclination angle of the fingerprint recognition light source 3 can be set according to the direction required by the light path in the glass cover plate 2, even if the fingerprint recognition light source 3 The angle between the light output surface and the lower surface of the glass cover plate 2 is set to θ.

Example five

As shown in FIG. 10, FIG. 10 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of this application. In Embodiment 5, the light-emitting assembly further includes: a second optical coupler 602, and the second optical coupler 602 includes a second optical coupler 602. The third surface 63, the fourth surface 64, and the fifth surface 65 connecting the third surface 63 and the fourth surface 64, and the third surface 63 of the second optical coupler 602 is used to attach to the lower surface of the glass cover plate 2, The light exit surface of the fingerprint identification light source 3 is used to adhere to the fourth surface 64 of the second optical coupler 602 through optical glue. The refractive index of the optical glue can be 1.4 to 1.6, including the endpoint value; the fingerprint identification light source 3 produces The light is reflected by the fifth surface 65 of the second optical coupler 602 and then enters the glass cover 2.

Specifically, the difference between the fifth embodiment and the fourth embodiment is that the structure of the optical coupler is different, and the fingerprint recognition light source 3 does not need to be arranged obliquely. Instead, the light path of the parallel emerging light is adjusted in the second optical coupler 602, for example The light path will be reflected, and then coupled into the glass cover plate 2 through the third surface 63, it is easier to control the angle between the initial incident light path in the glass cover plate 2 and the normal line of the plane where the glass cover plate 2 is located. In order to improve the light utilization rate generated by the fingerprint identification light source 3.

Example Six

As shown in FIG. 11, FIG. 11 is a schematic cross-sectional structure diagram of another electronic device in an embodiment of this application. In the sixth embodiment, the electronic device further includes: a middle frame 7 located on the side of the display screen 1 away from the glass cover 2 The fingerprint recognition light source 3 is used to be arranged on the middle frame 7; the light-emitting assembly also includes a reflector 600 located under the glass cover 2. The light emitted by the fingerprint recognition light source 3 is reflected by the reflector 600 and then enters the glass cover 2. , And the incident angle to the upper surface of the glass cover plate 2 is greater than or equal to the total reflection angle of the light signal from the glass cover plate 2 to the air.

Specifically, the difference between the sixth embodiment and the third, fourth, and fifth embodiments is that the fixed position of the fingerprint recognition light source 3 is different. The fingerprint recognition light source 3 is arranged on the middle frame 7 under the display screen 1, and the light source 3 can be recognized by fingerprints. It is fixed with the middle frame 7 to adjust the light path of the fingerprint recognition light source 3 to improve the light utilization rate generated by the fingerprint recognition light source 3, and because the fingerprint recognition light source 3 is located under the display screen 1, there is no need to occupy the frame area of the electronic device The space is conducive to the realization of narrow borders.

Optionally, as shown in FIG. 11, the reflective device 600 is arranged on the side of the display screen 1, and the reflective surface of the reflective device 600 is perpendicular to the upper surface of the glass cover 2.

On the basis of the foregoing embodiments, the different setting modes of the fingerprint identification light source position will be described as different embodiments.

Example Seven

As shown in FIG. 6, in the seventh embodiment, the fingerprint recognition light source 3 includes a first light source 31, and the display screen 1 includes a first position 101 opposite to the position where the first light source 31 is located, and opposite to the position where the optical fingerprint module 4 is located. The second position 102 is the second position 102 where the fingerprint detection area 10 is located, and the first position 101 is located at a position where the center of the second position 102 extends along the length direction of the display screen 1. Among them, the fingerprint detection area 10 is located near the bottom frame area 84 of the electronic device to facilitate the user to place fingers for fingerprint recognition. At the same time, the fingerprint recognition light source 3 is set in the bottom frame area 84 to prevent adverse effects on the display area. The location of the fingerprint detection area 10 is relatively close, which is convenient to provide the light source required for fingerprint identification.

Example eight

As shown in FIGS. 12 and 13, FIG. 12 is a top view of the second type of electronic device in an embodiment of this application, and FIG. 13 is a top view of the third type of electronic device in an embodiment of this application. The difference between the eighth embodiment and the seventh embodiment That is, in the eighth embodiment, the first position 101 is located on one side of the position where the center of the second position 102 extends along the length direction of the display screen 1. The difference between the structure shown in FIG. 12 and the structure shown in FIG. 6 is that two fingerprint recognition light sources 3 are provided in the bottom frame area 84. The difference between the structure shown in FIG. 13 and the structure shown in FIG. 12 is that the two fingerprint recognition light sources 3 are respectively located at opposite ends of the bottom frame area 84, and the fingerprint detection area 10 can be provided from different directions for fingerprint recognition. Light.

Example 9

As shown in FIG. 14, FIG. 14 is a top view of the fourth electronic device in the embodiment of the application. In Embodiment 9, the fingerprint recognition light source 3 includes a second light source 32 and a third light source 33, and the display screen 1 includes a second light source 32 and a third light source 33. The third position 103 opposite to the position of the light source 32, the fourth position 104 opposite to the position of the third light source 33, and the second position 102, the third position 103 and the fourth position 104 opposite to the position of the optical fingerprint module 4 It is arranged on both sides of the position extending along the length direction of the display screen 1 in the central position of the second position 102. In the structure shown in FIG. 12, the two fingerprint recognition light sources 3 are respectively located in the first side frame area 81 and the second side frame area 82 on the left and right sides, and the fingerprint recognition light source 3 and the fingerprint detection area 10 are both located near the bottom. . The difference between the ninth embodiment and the seventh and the eighth embodiment is that, in the ninth embodiment, the position of the fingerprint recognition light source and the position of the optical fingerprint module are arranged along the width direction of the display screen 1.

Example ten

On the basis of the seventh, eighth or ninth embodiment, as shown in FIG. 6, FIG. 12 to FIG. 16, FIG. 15 is a top view of the fifth electronic device in the embodiment of the application, and FIG. 16 is the sixth embodiment of the application. A top view of an electronic device. The electronic device includes a first side frame area 81 and a second side frame area 82 opposed to each other. The electronic device also includes a top frame area 83 and a bottom frame area 84 opposed to each other; the fingerprint detection area 10 and the first side frame area The distance between the areas 81 is h1, the distance to the second side frame area 82 is h2, the distance to the top frame area 83 is h3, and the distance to the bottom frame area 84 is h4, h3>h1, h3>h2 , H3>h4; the number of fingerprint identification light sources 3 is one or more; as shown in Figure 6, if the number of fingerprint identification light sources 3 is one, the fingerprint identification light source 3 is located in the bottom frame area 84; Figures 12 to 16 As shown, if the number of fingerprint recognition light sources 3 is multiple, the multiple fingerprint recognition light sources 3 are located in at least one of the first side frame area 81, the second side frame area 82, and the bottom frame area 84, and any one of them The distance between the fingerprint recognition light source 3 and the fingerprint detection area 10 is less than h3. In the structure shown in FIG. 15, three fingerprint recognition light sources 3 are provided in the bottom frame area 84, including the first position 101 located at the center of the second position 102 extending along the length direction of the display screen 1, and including The first position 101 is located on the side of the position where the center of the second position 102 extends along the length direction of the display screen 1. In the structure shown in FIG. 16, a fingerprint recognition light source 3 is provided in each of the first side frame area 81, the second side frame area 82 and the bottom frame area 84, wherein the third position 103 corresponding to the second light source 32 is located In the first side frame area 81, the fourth position 104 corresponding to the third light source 33 is located in the second side frame area 82, and the first position 101 corresponding to the first light source 31 is located in the bottom frame area 84.

As shown in FIGS. 3 to 16, an embodiment of the present application also provides a touch screen, including a glass cover 2 and a display screen 1 arranged under the glass cover 2, wherein the touch screen further includes the optical fingerprints in the foregoing embodiments Detection device; the light generated by the fingerprint recognition light source 3 and incident on the glass cover 2 has a first polarization direction, a first polarizer 21 is provided in the display screen 1, and the polarization direction of the first polarizer 21 is perpendicular to the first polarization direction.

Specifically, the specific structures and principles of the glass cover 2, the display screen 1, the optical fingerprint detection device, and the fingerprint light reflection layer 01 are the same as those in the foregoing embodiment, and will not be repeated here. The touch screen may be any touch screen device with a display function, such as a touch screen, a mobile phone, a tablet computer, a notebook computer, or a television. Among them, the display screen 1 may specifically be, for example, an OLED (Organic Light-Emitting Diode, OLED) display screen. Wherein, as shown in FIGS. 4, 7 and 8, the display screen 1 may specifically include a first polarizer 21, a quarter-wave plate 22, a touch layer 23, an encapsulation layer 24, and an organic light-emitting device stacked in sequence. Layer 25 and circuit control layer 26.

Optionally, the angle between the initial light path that the light generated by the fingerprint recognition light source 3 enters the glass cover 2 and the normal F of the plane where the glass cover 2 is located is θ, 41.8°<θ<72.4°.

Optionally, the first polarizer 21 is attached to the surface of the glass cover plate 2 through the glue layer 20.

Optionally, referring to the description of the first embodiment above, the light-emitting assembly further includes: a second polarizer 30, which is located between the fingerprint recognition light source 3 and the glass cover 2, so that the light generated by the fingerprint recognition light source 3 The second polarizer 30 is incident on the glass cover plate 2, and the second polarizer 30 has the first polarization direction.

Optionally, as shown in FIG. 7, the second polarizer 30 is attached to the surface of the glass cover plate 2; the fingerprint recognition light source 3 is attached to the second polarizer 30 away from the glass cover plate 2 through optical glue 5 or an optical coupler. The surface on one side.

Optionally, as shown in FIG. 8, the second polarizer 30 is attached to the light-emitting surface of the fingerprint identification light source 3; the second polarizer 30 is attached to the surface of the glass cover 2 through the optical glue 5 or an optical coupler.

An embodiment of the present application also provides an electronic device, including the optical fingerprint detection device in the foregoing embodiments. The specific structure and principle of the optical fingerprint detection device are the same as the foregoing embodiment, and will not be repeated here.

The above descriptions are only preferred embodiments of this application and are not intended to limit this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in this application Within the scope of protection.

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

Claims

An optical fingerprint detection device, which is applied to an electronic device with a display screen, the electronic device has a glass cover, and is characterized in that the device includes:

A light-emitting component, the light-emitting component includes a fingerprint recognition light source, the fingerprint recognition light source is used to provide excitation light for fingerprint recognition, the light emitted by the fingerprint recognition light source is incident on the upper surface of the glass cover at an angle of incidence Greater than or equal to the total reflection angle of the light signal incident from the glass cover plate to the air;

The optical fingerprint detection device also includes an optical fingerprint module, which is arranged below the fingerprint detection area of the display screen, and is used to detect that the fingerprint recognition light source illuminates the finger above the fingerprint detection area and transmits from the finger And the light signal passing through the display screen;

The light generated by the fingerprint recognition light source has a first polarization direction after being incident on the glass cover, a first polarizer is arranged in the display screen, and the polarization direction of the first polarizer is perpendicular to the first polarizer. Polarization direction.
The optical fingerprint detection device according to claim 1, wherein:

The angle between the initial light path of the light generated by the fingerprint identification light source entering the glass cover and the normal of the plane where the glass cover is located is θ, 41.8°<θ<72.4°.
The optical fingerprint detection device according to claim 1, wherein:

The light generated by the fingerprint recognition light source is infrared light.
The optical fingerprint detection device according to claim 3, wherein:

The wavelength of the light generated by the fingerprint identification light source is λ, 920nm<λ<960nm.
The optical fingerprint detection device according to claim 1, wherein:

The effective wavelength range of the first polarizer includes the wavelength band of light generated by the fingerprint identification light source and the visible light wavelength band;

The display screen further includes a quarter wave plate, and the quarter wave plate is located on a side of the first polarizer away from the glass cover plate.
The optical fingerprint detection device according to claim 1, wherein:

The first polarizer has a reflectance greater than 0.8 for the light generated by the fingerprint recognition light source.
The optical fingerprint detection device according to claim 1, wherein:

The first polarizer is used for attaching to the surface of the glass cover through an adhesive layer.
The optical fingerprint detection device according to claim 1, wherein the light-emitting component further comprises:

The second polarizer, the second polarizer is located between the fingerprint recognition light source and the glass cover, so that the light generated by the fingerprint recognition light source is incident on the glass cover through the second polarizer , The second polarizer has the first polarization direction.
The optical fingerprint detection device according to claim 8, wherein:

The second polarizer is used to be attached to the surface of the glass cover plate;

The fingerprint recognition light source is used for attaching to the surface of the second polarizer on the side away from the glass cover through optical glue or an optical coupler.
The optical fingerprint detection device according to claim 8, wherein:

The second polarizer is used to be attached to the light-emitting surface of the fingerprint identification light source;

The second polarizer is used for attaching to the surface of the glass cover through optical glue or an optical coupler.
8. The optical fingerprint detection device according to claim 8, wherein the natural light generated by the fingerprint recognition light source passes through the second polarizer and is converted into polarized light with the first polarization direction.
The optical fingerprint detection device according to claim 1, wherein:

The light generated by the fingerprint recognition light source has the first polarization direction.
A touch screen, comprising a glass cover and a display screen arranged under the glass cover, wherein the touch screen further comprises the optical fingerprint detection device according to any one of claims 1 to 12; the fingerprint The light generated by the identifying light source has a first polarization direction after being incident on the glass cover, a first polarizer is arranged in the display screen, and the polarization direction of the first polarizer is perpendicular to the first polarization direction.
The touch screen according to claim 13, wherein:

The angle between the initial light path of the light generated by the fingerprint identification light source entering the glass cover and the normal of the plane where the glass cover is located is θ, 41.8°<θ<72.4°.
The touch screen according to claim 13, wherein:

The effective wavelength range of the first polarizer includes the wavelength range of light generated by the fingerprint identification light source and the visible light wavelength range;

The display screen further includes a quarter wave plate, and the quarter wave plate is located on a side of the first polarizer away from the glass cover plate.
The touch screen according to claim 13, wherein:

The first polarizer has a reflectance greater than 0.8 for the light generated by the fingerprint recognition light source.
The touch screen according to claim 13, wherein:

The first polarizer is attached to the surface of the glass cover through an adhesive layer.
The touch screen according to claim 13, wherein the light-emitting component further comprises:

The second polarizer, the second polarizer is located between the fingerprint recognition light source and the glass cover, so that the light generated by the fingerprint recognition light source is incident on the glass cover through the second polarizer , The second polarizer has the first polarization direction.
The touch screen according to claim 18, wherein:

The second polarizer is attached to the surface of the glass cover plate;

The fingerprint recognition light source is attached to the surface of the second polarizer on the side away from the glass cover through optical glue or an optical coupler.
The touch screen according to claim 18, wherein:

The second polarizer is attached to the light emitting surface of the fingerprint identification light source;

The second polarizer is attached to the surface of the glass cover through optical glue or an optical coupler.
An electronic device, characterized by comprising the optical fingerprint detection device according to any one of claims 1 to 12.