Fingerprint recognition module, fingerprint recognition method, and display device

Abstract

The present disclosure provides a fingerprint recognition module, a fingerprint recognition method, and a display device. The fingerprint recognition module includes: a base substrate; a light convergence layer, which is arranged on the base substrate and is configured to perform total reflection and convergence of stray reflected light reflected by the fingerprint; a photosensitive layer, which is arranged between the base substrate and the light convergence layer and is configured to receive the stray reflected light after convergence by the light convergence layer and the main reflected light reflected by the fingerprint to generate a fingerprint signal. The fingerprint recognition module, the fingerprint recognition method, and the display device disclosed in the present disclosure can improve the accuracy of fingerprint recognition.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to a fingerprint recognition module, a fingerprint recognition method, and a display device. Background Art

[0002] With the continuous development of terminal technology, the application of electronic devices is becoming more and more extensive. Due to the uniqueness of skin patterns such as fingerprint patterns or palm patterns, in order to protect the information security of users, the use of fingerprint recognition functions on electronic devices is becoming more and more common, such as for mobile phone unlocking, mobile payment (such as payment, transfer), etc.

[0003] In the related art, the light emitted by the display device is totally reflected at the fingerprint valley position on the interface formed by the display device and the finger, while the reflectivity at the fingerprint ridge position is lower. These reflected lights are collected by the photosensitive unit to generate a fingerprint pattern.

[0004] At present, the light reflected by the fingerprint valley includes the main reflected light and the stray reflected light. Since the stray reflected light has a large reflection range, it affects the accuracy of fingerprint recognition. Summary of the invention

[0005] In view of this, the purpose of the present disclosure is to provide a fingerprint recognition module, a fingerprint recognition method, and a display device.

[0006] Based on the above objectives, the present disclosure provides a fingerprint recognition module, including:

[0007] substrate substrate;

[0008] A light converging layer, disposed on the base substrate, configured to converge stray reflected light reflected by the fingerprint by total reflection;

[0009] The photosensitive layer is disposed between the base substrate and the light converging layer, and is configured to receive the stray reflected light converged by the light converging layer and the main reflected light reflected by the fingerprint to generate a fingerprint signal.

[0010] Optionally, the light converging layer includes:

[0011] A first electrode layer is disposed on the photosensitive layer;

[0012] A plurality of first microstructure units are arranged on the first electrode layer;

[0013] A plurality of second microstructure units are arranged on the first electrode layer and spaced apart from the first microstructure units, and a slope surface is formed at the junction of the second microstructure units and the first microstructure units, and an acute angle is formed between the slope surface and the first electrode layer;

[0014] A second electrode layer is disposed on a side of the second microstructure unit away from the photosensitive layer;

[0015] Wherein, the first electrode layer and the second electrode layer are configured to: form an electric field between the first electrode layer and the second electrode layer, so that the refractive index of the second microstructure unit is increased to be greater than the refractive index of the first microstructure unit, so as to reflect the stray reflected light incident on the slope surface to the photosensitive layer.

[0016] Optionally, the refractive index of the second microstructure unit is increased to 1.1 to 1.2 times the refractive index of the first microstructure unit.

[0017] Optionally, the acute angle θ between the slope surface and the first electrode layer satisfies:

[0018] arcsin(n1 / n2)≤θ<90°

[0019] Wherein, n1 represents the refractive index of the first microstructure unit, and n2 represents the refractive index of the second microstructure unit.

[0020] Optionally, the first microstructure unit is a strip structure with an inverted trapezoidal cross section, and the second microstructure unit is a strip structure with a regular trapezoidal cross section.

[0021] Optionally, the first microstructure unit is a block structure with an inverted trapezoidal cross section, the second microstructure unit is a block structure with a regular trapezoidal cross section, and a plurality of the first microstructure units and a plurality of the second microstructure units are arranged in an array with intervals.

[0022] Optionally, also include:

[0023] The flat layer is disposed on the first microstructure unit and the second microstructure unit, and is integrally formed with the second microstructure unit.

[0024] Optionally, the first electrode layer includes a plurality of first electrode units, and an orthographic projection of the first electrode unit on the base substrate coincides with an orthographic projection of a bottom surface of the second microstructure unit close to the photosensitive layer on the base substrate.

[0025] Optionally, the second electrode layer includes a planar electrode layer structure; or, the second electrode layer includes a plurality of second electrode units, and an orthographic projection of the second electrode unit on the base substrate coincides with an orthographic projection of the first electrode unit on the base substrate.

[0026] Optionally, also include:

[0027] The touch sensor is configured to collect pressure information of a fingerprint position, and generate an electrical signal based on the pressure information to form an electric field between the first electrode layer and the second electrode layer.

[0028] The present disclosure also provides a display device, comprising a fingerprint recognition module as described in any one of the above items.

[0029] Optionally, the display device also includes a display panel, the fingerprint recognition module includes a light converging layer, a photosensitive layer, a base substrate and a touch sensor, the light converging layer, the photosensitive layer and the base substrate are stacked in sequence on the backlight surface of the display panel in a direction away from the display panel, and the touch sensor is arranged on the light emitting surface of the display panel.

[0030] The present disclosure also provides a fingerprint recognition method, which is applied to a fingerprint recognition module, wherein the fingerprint recognition module comprises a base substrate, a photosensitive layer, and a light converging layer which are stacked in sequence; the method comprises:

[0031] The stray reflected light reflected by the fingerprint is totally reflected and converged by the light converging layer;

[0032] The stray reflected light converged by the light converging layer and the main reflected light reflected by the fingerprint are received by the photosensitive layer to generate a fingerprint signal.

[0033] Optionally, the light converging layer includes a first electrode layer, a second electrode layer, and a plurality of first microstructure units and a plurality of second microstructure units disposed between the first electrode layer and the second electrode layer, and a slope surface is formed at the junction of the second microstructure unit and the first microstructure unit, and an acute angle is formed between the slope surface and the first electrode layer;

[0034] The method of performing total reflection and converging of stray reflected light reflected by the fingerprint through the light converging layer comprises:

[0035] An electric field is formed between the first electrode layer and the second electrode layer, so that the refractive index of the second microstructure unit is increased to be greater than the refractive index of the first microstructure unit, so as to reflect the stray reflected light incident on the slope surface to the photosensitive layer.

[0036] Optionally, the fingerprint recognition module further includes a touch sensor; and the method further includes:

[0037] The pressure information of the fingerprint position is collected, and an electrical signal is generated based on the pressure information to form an electric field between the first electrode layer and the second electrode layer.

[0038] From the above, it can be seen that the fingerprint recognition module, fingerprint recognition method and display device provided by the present invention, through the light converging layer, totally reflects and converges the stray reflected light reflected by the fingerprint and transmits it to the photosensitive layer, so that the photosensitive layer can receive and process the stray reflected light converged by the light converging layer and the main reflected light reflected by the fingerprint, so as to generate a fingerprint signal, which not only avoids the interference of stray reflected light on fingerprint recognition, but also can utilize the stray reflected light to realize fingerprint recognition together, thereby improving the accuracy of fingerprint recognition. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 This is a schematic diagram of the fingerprint recognition principle of the embodiment of the present disclosure;

[0041] Figure 2 This is a schematic diagram of the structure of the fingerprint recognition module according to the embodiment of the present disclosure;

[0042] Figure 3 A schematic diagram of the total reflection principle of stray reflected light according to an embodiment of the present disclosure;

[0043] Figure 4 Another structural diagram of the fingerprint recognition module according to the embodiment of the present disclosure;

[0044] Figure 5 It is a schematic diagram of the structure of the display device according to an embodiment of the present disclosure;

[0045] Figure 6 A schematic diagram of the fingerprint recognition method according to an embodiment of the present disclosure;

[0046] Figure 7 Another schematic diagram of the fingerprint recognition method according to the embodiment of the present disclosure. DETAILED DESCRIPTION

[0047] In order to make the objectives, technical solutions and advantages of the present disclosure more clearly understood, the present disclosure is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0048] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0049] The under-screen fingerprint recognition technology integrates the fingerprint sensor under the display panel. Since there is a certain gap between the pixels of the display panel, these gaps form a light leakage area, thus ensuring that light can pass through the display panel. Figure 1 As shown, when the user touches the screen with a finger, the screen can emit light to illuminate the finger area, and the reflected light illuminating the fingerprint passes through the gaps between the screen pixels and returns to the image sensor close to the display panel.

[0050] Fingerprints include fingerprint ridges and valleys. Since the fingerprint tissue in the fingerprint ridge area absorbs light, the light reflected from the fingerprint ridges becomes darker, while the light reflected from the fingerprint valleys is relatively brighter. Therefore, the brightness difference between the fingerprint ridges and the fingerprint valleys can form a fingerprint pattern on the image sensor. The image sensor set under the display device realizes the recognition of the fingerprint under the screen by detecting the aforementioned reflected light carrying the user's fingerprint information.

[0051] During the fingerprint recognition process, the light reflected by the fingerprint valley includes main reflected light and stray reflected light, and the stray reflected light will interfere with the fingerprint recognition. If the stray reflected light is not processed, the accuracy of fingerprint recognition will be affected.

[0052] Based on the above reasons, the present disclosure provides a fingerprint recognition module that can converge stray reflected light for fingerprint recognition, thereby improving the accuracy of fingerprint recognition.

[0053] like Figure 2 As shown, the fingerprint recognition module described in the embodiment of the present disclosure includes a base substrate 1, a light converging layer 3 and a photosensitive layer 2.

[0054] The light converging layer 2 is disposed on the base substrate 1, and is configured to perform total reflection and convergence of the stray reflected light reflected by the fingerprint and then transmit it to the photosensitive layer 2. The photosensitive layer 2 is disposed between the base substrate 1 and the light converging layer 3, and is configured to receive the stray reflected light converged by the light converging layer 2 and the main reflected light reflected by the fingerprint to generate a fingerprint signal.

[0055] The fingerprint recognition module described in the embodiment of the present disclosure totally reflects and converges the stray reflected light reflected by the fingerprint through the light convergence layer 2 and transmits it to the photosensitive layer 2, so that the photosensitive layer 2 can receive and process the stray reflected light converged by the light convergence layer 2 and the main reflected light reflected by the fingerprint, thereby generating a fingerprint signal. This not only avoids the interference of the stray reflected light on fingerprint recognition, but also can utilize the stray reflected light to realize fingerprint recognition together, thereby improving the accuracy of fingerprint recognition.

[0056] Optionally, the main reflected light and the stray reflected light in this embodiment may both be the light reflected back from the fingerprint valley.

[0057] Optionally, the base substrate 1 may be a glass plate, a quartz plate, a metal plate or a resin plate, etc. For example, the material of the base substrate 1 may include an organic material, such as a resin material such as polyimide (PI), polycarbonate, polyacrylate, polyetherimide, polyethersulfone, polyethylene terephthalate and polyethylene naphthalate, and the base substrate 1 may be a flexible substrate or a non-flexible substrate, which is not limited in the embodiments of the present disclosure.

[0058] Optionally, the photosensitive layer 2 may include structures such as an image sensor or a fingerprint sensor. When the photosensitive layer 2 includes an image sensor, the image sensor includes a plurality of photosensitive unit arrays arranged in an array, and the photosensitive unit array can receive the main reflected light reflected by the fingerprint and the stray reflected light converged by the light converging layer 2, and generate corresponding electrical signals based on the main reflected light and the stray reflected light, and finally generate a fingerprint signal, which can be used to generate information such as a fingerprint image. When the photosensitive layer 2 includes a fingerprint sensor, the fingerprint sensor can be composed of a photodiode array and a transistor, wherein the photodiode array can absorb the main reflected light reflected by the fingerprint and the stray reflected light converged by the light converging layer 2, and the transistor can convert the light received by the photodiode array into an electrical signal output corresponding to the light intensity, so as to generate a fingerprint signal.

[0059] In some embodiments of the present disclosure, Figure 2As shown, the light converging layer 3 includes a first electrode layer 31 , a second electrode layer 32 , and a plurality of first microstructure units 33 and a plurality of second microstructure units 34 disposed between the first electrode layer 31 and the second electrode layer 32 .

[0060] like Figure 2 As shown, in this embodiment, the first electrode layer 31 is disposed on the photosensitive layer 2. A plurality of first microstructure units 33 and a plurality of second microstructure units 34 are disposed on the first electrode layer 31 and are disposed away from the substrate 1. The second microstructure unit 34 is disposed at intervals from the first microstructure unit 33, and a slope surface is formed at the junction between the second microstructure unit 34 and the first microstructure unit 33, and an acute angle is formed between the slope surface and the first electrode layer 31; the second electrode layer 32 is disposed on the side of the second microstructure unit 34 away from the photosensitive layer.

[0061] Wherein, the first electrode layer 31 and the second electrode layer 32 are configured to: form an electric field between the first electrode layer 31 and the second electrode layer 32, so that the refractive index of the second microstructure unit 34 is increased to be greater than the refractive index of the first microstructure unit 33, so as to reflect the stray reflected light incident on the slope surface to the photosensitive layer 2.

[0062] In the present embodiment, when no electric field is formed between the first electrode layer 31 and the second electrode layer 32, the refractive index of the first microstructure unit 33 is substantially the same as the refractive index of the second microstructure unit 34. For example, the refractive index of the first microstructure unit 33 and the refractive index of the second microstructure unit 34 differ by only 0-0.002. Thus, when light is transmitted between the first microstructure unit 33 and the second microstructure unit 34, there is almost no total reflection. Thus, when the display device is displaying normally, the displayed picture will not be unevenly displayed in brightness due to the total reflection of light between the first microstructure unit 33 and the second microstructure unit 34.

[0063] When fingerprint recognition is required, an electric field will be formed between the first electrode layer 31 and the second electrode layer 32. At this time, under the action of the electric field, the refractive index of the second microstructure unit 34 will increase until the refractive index of the second microstructure unit 34 is greater than the refractive index of the first microstructure unit 33, so that the stray reflected light incident on the slope surface from the second microstructure unit 34 can be totally reflected. The stray reflected light after total reflection can be transmitted to the photosensitive layer 2 and absorbed by the photosensitive layer 2, thereby improving the accuracy of fingerprint recognition.

[0064] Optionally, the connection points between two adjacent slope surfaces and the first electrode layer 31 do not overlap and have a certain distance therebetween, thereby ensuring that the stray reflected light after total reflection by the slope surfaces can be transmitted to the photosensitive layer 2 .

[0065] In some optional embodiments, when an electric field is formed between the first electrode layer 31 and the second electrode layer 32, the size of the electric field needs to be controlled so that the refractive index of the second microstructure unit 34 is increased to 1.1 to 1.2 times the refractive index of the first microstructure unit 33, thereby ensuring that the stray reflected light is not only totally reflected when incident on the slope surface, but also can enter the photosensitive layer 2 after total reflection and be absorbed by the photosensitive layer 2.

[0066] In some optional embodiments, such as Figure 3 As shown, the acute angle θ between the slope surface and the first electrode layer 31 satisfies:

[0067] arcsin(n1 / n2)≤θ<90°

[0068] Wherein, n1 represents the refractive index of the first microstructure unit 33 when no electric field is applied, n2 represents the refractive index of the second microstructure unit 34 when no electric field is applied, and arcsin(x) represents an angle in degrees.

[0069] Optionally, when the acute angle θ between the slope surface and the first electrode layer 31 is in the range of 60°-80°, the light converging layer 3 can achieve a better reflection effect on the stray reflected light.

[0070] In some embodiments, Figure 2 As shown, the first microstructure unit 33 is a strip structure with an inverted trapezoidal cross section, and the second microstructure unit 34 is a strip structure with a regular trapezoidal cross section, and the two are arranged at intervals.

[0071] In other embodiments, the first microstructure unit 33 is a block structure with an inverted trapezoidal cross-section, the second microstructure unit 34 is a block structure with a regular trapezoidal cross-section, and a plurality of the first microstructure units 33 and a plurality of the second microstructure units 34 are arranged in an array at intervals, thereby increasing the number of slope surfaces between the first microstructure units 33 and the second microstructure units 34, improving the reflection effect on stray reflected light, and further improving the accuracy of fingerprint recognition.

[0072] In some embodiments, Figure 4 As shown, the fingerprint recognition module further includes a flat layer 35. The flat layer 35 is disposed on the first microstructure unit 33 and the second microstructure unit 34, and is integrally formed with the second microstructure unit 34. The flat layer 35 is provided so that the first microstructure unit 33 and the second microstructure unit 34 are flat on one side facing the second electrode layer 32, thereby facilitating the formation of structures such as the second electrode layer 32.

[0073] Optionally, after forming the first microstructure units 33 with an inverted trapezoidal cross section on the first electrode layer 31 , the gaps between the first microstructure units 33 are filled with the material of the second microstructure units 34 , and the structure of the flat layer 35 is formed while forming the second microstructure units 34 .

[0074] In some embodiments, the first electrode layer 31 includes a plurality of first electrode units, and the orthographic projection of the first electrode unit on the base substrate 1 coincides with the orthographic projection of the second microstructure unit 34 on the base substrate 1 near the bottom surface of the photosensitive layer, so that the electric field formed between the first electrode layer 31 and the second electrode layer 32 can only apply an electric field to the second microstructure unit 34, so that only the refractive index of the second microstructure unit 34 is increased to be greater than the refractive index of the first microstructure unit 33, thereby achieving total reflection of stray reflected light.

[0075] Optional, such as Figure 4 As shown, the second electrode layer 32 includes a planar electrode layer structure, so as to facilitate the manufacture and formation of the second electrode layer 32. Alternatively, the second electrode layer 32 includes a plurality of second electrode units, and the orthographic projection of the second electrode unit on the base substrate 1 coincides with the orthographic projection of the first electrode unit on the base substrate 1, so that the electric field can be applied only to the second microstructure unit 34, so that only the refractive index of the second microstructure unit 34 is increased to be greater than the refractive index of the first microstructure unit 33, so as to achieve total reflection of stray reflected light.

[0076] In some other embodiments of the present disclosure, the fingerprint recognition module further includes a touch sensor. The touch sensor is configured to collect pressure information of the fingerprint position, and generate an electrical signal based on the pressure information to form an electric field between the first electrode layer 31 and the second electrode layer 32. In this embodiment, when a finger touches the fingerprint recognition position, pressure is formed on the display device; when the pressure signal corresponding to the fingerprint recognition is detected, the touch sensor can convert the pressure signal into an electrical signal, which can be processed to form an electric field signal applied between the first electrode layer 31 and the second electrode layer 32. Based on the electric field signal, an electric field can be formed between the first electrode layer 31 and the second electrode layer 32, so that the refractive index of the second microstructure unit 34 can be increased to be greater than the refractive index of the first microstructure unit 33, thereby achieving total reflection of stray reflected light.

[0077] Optionally, the touch sensor may be disposed on the light emitting surface of the display panel, or may be disposed on the backlight surface of the display panel.

[0078] Based on the same inventive concept, an embodiment of the present disclosure further provides a display device, which includes a fingerprint recognition module as described in any of the above embodiments.

[0079] like Figure 5 As shown, the display device further includes a display panel 4. The display panel 4 may include a liquid crystal display panel, an OLED display panel, etc., which is not limited in the embodiments of the present disclosure.

[0080] The fingerprint recognition module includes a light converging layer 3, a photosensitive layer 2, a base substrate 1 and a touch sensor 5. The light converging layer 3, the photosensitive layer 2 and the base substrate 1 are sequentially stacked on the backlight surface of the display panel 4 in a direction away from the display panel 4, and the touch sensor 5 is arranged on the light emitting surface of the display panel 4.

[0081] Optionally, the display device may further include a polarizer and a cover plate disposed on the display panel 4 .

[0082] The display device of the above embodiment includes the fingerprint recognition module described in any of the above embodiments, and has the beneficial effects of the corresponding fingerprint recognition module embodiments, which will not be described in detail here.

[0083] It should be noted that the display device in this embodiment can be: electronic paper, mobile phone, tablet computer, television, notebook computer, digital photo frame, navigator, or any other product or component with a display function.

[0084] It should be noted that in the accompanying drawings, the sizes of layers and regions may be exaggerated for clarity of illustration. It is also understood that when an element or layer is referred to as being "on" another element or layer, it may be directly on the other element, or there may be an intermediate layer. In addition, it is understood that when an element or layer is referred to as being "under" another element or layer, it may be directly under the other element, or there may be more than one intermediate layer or element. In addition, it is also understood that when a layer or element is referred to as being "between" two layers or two elements, it may be the only layer between the two layers or two elements, or there may also be more than one intermediate layer or element. Similar reference numerals throughout the text indicate similar elements.

[0085] Based on the same inventive concept, the present disclosure also provides a fingerprint recognition method. The fingerprint recognition method is applied to a fingerprint recognition module, wherein: Figure 2 , Figure 4 As shown, the fingerprint recognition module includes a base substrate 1, a photosensitive layer 2 and a light converging layer 3 which are stacked in sequence. Figure 6 As shown, the fingerprint recognition method includes:

[0086] Step S101, the stray reflected light reflected by the fingerprint is totally reflected and converged by the light converging layer.

[0087] Step S102 , receiving the stray reflected light converged by the light converging layer and the main reflected light reflected by the fingerprint through the photosensitive layer to generate a fingerprint signal.

[0088] In some optional embodiments, such as Figure 2 , Figure 4 As shown, the light converging layer 3 includes a first electrode layer 31, a second electrode layer 32, and a plurality of first microstructure units 33 and a plurality of second microstructure units 34 disposed between the first electrode layer 31 and the second electrode layer 32, and a slope surface is formed at the junction of the second microstructure unit 34 and the first microstructure unit 31, and an acute angle is formed between the slope surface and the first electrode layer 31. In step S101, the stray reflected light reflected by the fingerprint is totally reflected and converged by the light converging layer, including: forming an electric field between the first electrode layer and the second electrode layer, so that the refractive index of the second microstructure unit is increased to be greater than the refractive index of the first microstructure unit, so as to reflect the stray reflected light incident on the slope surface to the photosensitive layer.

[0089] Optionally, the fingerprint recognition module further includes a touch sensor; the method further includes: collecting pressure information of the fingerprint position, and generating an electrical signal based on the pressure information to form an electric field between the first electrode layer and the second electrode layer. In this embodiment, the pressure information of the fingerprint position can be collected by the touch sensor, and an electrical signal for forming an electric field between the first electrode layer and the second electrode layer can be generated based on the pressure information.

[0090] In some optional embodiments, such as Figure 7 As shown, the fingerprint recognition method further includes:

[0091] Step S201, collecting pressure information of the fingerprint position, and generating an electrical signal based on the pressure information.

[0092] In this step, when it is detected that a finger touches the fingerprint recognition position, the touch sensor 5 collects pressure information of the fingerprint position and generates an electrical signal based on the pressure information. The electrical signal can be processed to form an electric field signal applied between the first electrode layer 31 and the second electrode layer 32.

[0093] Meanwhile, only when a finger is detected touching the fingerprint recognition position, the touch sensor 5 will generate an electrical signal for applying an electric field between the first electrode layer 31 and the second electrode layer 32. When a finger is not detected touching the fingerprint recognition position, no electrical signal will be generated and no electric field will be applied between the first electrode layer 31 and the second electrode layer 32, so that the total reflection of light between the first microstructure unit 33 and the second microstructure unit 34 will cause uneven brightness and darkness of the screen.

[0094] Step S202: applying the electrical signal between the first electrode layer and the second electrode layer, thereby forming an electric field between the first electrode layer and the second electrode layer.

[0095] In the present embodiment, since the refractive index of the second microstructure unit 34 needs to be increased to 1.1 to 1.2 times the refractive index of the first microstructure unit 33 in order to achieve total reflection of the stray reflected light when it is incident on the slope surface, it is necessary to control the size of the electric field so that the refractive index of the second microstructure unit 34 is increased to 1.1 to 1.2 times the refractive index of the first microstructure unit 33, thereby ensuring that the stray reflected light can not only be totally reflected when it is incident on the slope surface, but also can enter the photosensitive layer 2 after total reflection and be absorbed by the photosensitive layer 2.

[0096] In step S203, after a certain electric field is formed between the first electrode layer and the second electrode layer, the refractive index of the second microstructure unit at the electric field region increases, so that the stray reflected light incident on the slope surface through the second microstructure unit can be totally reflected to the photosensitive layer.

[0097] In this embodiment, the orthographic projections of the plurality of first electrode units included in the first electrode layer 31 on the base substrate 1 coincide with the orthographic projections of the second microstructure unit 34 on the base substrate 1 near the bottom surface of the photosensitive layer, so that the electric field formed between the first electrode layer 31 and the second electrode layer 32 can only apply the electric field to the second microstructure unit 34. The second electrode layer 32 may include a planar electrode layer structure. Alternatively, the second electrode layer 32 may also include a plurality of second electrode units, and the orthographic projections of the second electrode units on the base substrate 1 coincide with the orthographic projections of the first electrode units on the base substrate 1, so that the electric field can only be applied to the second microstructure unit 34.

[0098] In step S204, the photosensitive layer 2 collects the stray reflected light and the main reflected light reflected by the fingerprint after being converged by the light converging layer 2, and generates a fingerprint signal, and finally generates a fingerprint image. Since the light converging layer 2 can totally reflect the stray light reflected from the fingerprint valley and converge it to the photosensitive layer 2, it not only avoids the interference of the stray reflected light on the fingerprint recognition, but also can use the stray reflected light to realize the fingerprint recognition together, thereby improving the accuracy of the fingerprint recognition.

[0099] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples. Based on the concept of the present disclosure, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of simplicity.

[0100] In addition, to simplify the description and discussion, and in order not to make the embodiments of the present disclosure difficult to understand, the known power / ground connections to the integrated circuit (IC) chips and other components may or may not be shown in the provided figures. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present disclosure difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present disclosure will be implemented (that is, these details should be fully within the scope of understanding of those skilled in the art). Where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it is apparent to those skilled in the art that the embodiments of the present disclosure can be implemented without these specific details or with changes in these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0101] Although the present disclosure has been described in conjunction with specific embodiments of the present disclosure, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.

[0102] The embodiments of the present disclosure are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A fingerprint recognition module, comprising: substrate substrate; A light converging layer, disposed on the base substrate, configured to converge stray reflected light reflected by the fingerprint by total reflection; A photosensitive layer, disposed between the base substrate and the light converging layer, configured to receive the stray reflected light converged by the light converging layer and the main reflected light reflected by the fingerprint to generate a fingerprint signal; Wherein, the light converging layer comprises: A first electrode layer is disposed on the photosensitive layer; A plurality of first microstructure units are arranged on the first electrode layer; A plurality of second microstructure units are arranged on the first electrode layer and spaced apart from the first microstructure units, and a slope surface is formed at the junction of the second microstructure units and the first microstructure units, and an acute angle is formed between the slope surface and the first electrode layer; A second electrode layer is disposed on a side of the second microstructure unit away from the photosensitive layer; Wherein, the first electrode layer and the second electrode layer are configured to: form an electric field between the first electrode layer and the second electrode layer, so that the refractive index of the second microstructure unit is increased to be greater than the refractive index of the first microstructure unit, so as to reflect the stray reflected light incident on the slope surface to the photosensitive layer.

2. The fingerprint recognition module according to claim 1, wherein: The refractive index of the second microstructure unit is increased to 1.1 to 1.2 times the refractive index of the first microstructure unit.

3. The fingerprint recognition module according to claim 1, wherein: The acute angle θ between the slope surface and the first electrode layer satisfies: Wherein, n1 represents the refractive index of the first microstructure unit, and n2 represents the refractive index of the second microstructure unit.

4. The fingerprint recognition module according to claim 1, wherein: The first microstructure unit is a strip structure with an inverted trapezoidal cross section, and the second microstructure unit is a strip structure with a regular trapezoidal cross section.

5. The fingerprint recognition module according to claim 1, wherein: The first microstructure unit is a block structure with an inverted trapezoidal cross section, the second microstructure unit is a block structure with a regular trapezoidal cross section, and a plurality of the first microstructure units and a plurality of the second microstructure units are arranged in an array with intervals.

6. The fingerprint recognition module according to claim 4 or 5, further comprising: The flat layer is disposed on the first microstructure unit and the second microstructure unit, and is integrally formed with the second microstructure unit.

7. The fingerprint recognition module according to claim 4 or 5, wherein: The first electrode layer includes a plurality of first electrode units, and the orthographic projection of the first electrode unit on the base substrate coincides with the orthographic projection of the bottom surface of the second microstructure unit close to the photosensitive layer on the base substrate.

8. The fingerprint recognition module according to claim 7, wherein: The second electrode layer includes a planar electrode layer structure; or, the second electrode layer includes a plurality of second electrode units, and the orthographic projection of the second electrode unit on the base substrate coincides with the orthographic projection of the first electrode unit on the base substrate.

9. The fingerprint recognition module according to claim 1, further comprising: The touch sensor is configured to collect pressure information of a fingerprint position, and generate an electrical signal based on the pressure information to form an electric field between the first electrode layer and the second electrode layer.

10. A display device, comprising the fingerprint recognition module according to any one of claims 1 to 9.

11. The display device according to claim 10, wherein: The display device also includes a display panel, and the fingerprint recognition module includes a light converging layer, a photosensitive layer, a base substrate and a touch sensor. The light converging layer, the photosensitive layer and the base substrate are stacked in sequence on the backlight surface of the display panel in a direction away from the display panel, and the touch sensor is arranged on the light emitting surface of the display panel.

12. A fingerprint recognition method, applied to a fingerprint recognition module, the fingerprint recognition module comprising a base substrate, a photosensitive layer and a light converging layer stacked in sequence; the method comprising: The stray reflected light reflected by the fingerprint is totally reflected and converged by the light converging layer; The photosensitive layer receives the stray reflected light converged by the light converging layer and the main reflected light reflected by the fingerprint to generate a fingerprint signal; The light converging layer includes a first electrode layer, a second electrode layer, and a plurality of first microstructure units and a plurality of second microstructure units disposed between the first electrode layer and the second electrode layer, and a slope surface is formed at the junction of the second microstructure unit and the first microstructure unit, and an acute angle is formed between the slope surface and the first electrode layer; The method of performing total reflection and converging of stray reflected light reflected by the fingerprint through the light converging layer comprises: An electric field is formed between the first electrode layer and the second electrode layer, so that the refractive index of the second microstructure unit is increased to be greater than the refractive index of the first microstructure unit, so as to reflect the stray reflected light incident on the slope surface to the photosensitive layer.

13. The fingerprint recognition method according to claim 12, wherein: The fingerprint recognition module further includes a touch sensor; and the method further includes: The pressure information of the fingerprint position is collected, and an electrical signal is generated based on the pressure information to form an electric field between the first electrode layer and the second electrode layer.

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