CN116018032A - Display screen, fingerprint image acquisition method and display device - Google Patents

Abstract

The present disclosure provides a display screen, a fingerprint image acquisition method and a display device, the display screen comprising: a substrate base; a photosensitive element disposed on one side of the substrate base plate; the pixel defining layer is arranged on one side of the photosensitive element, which is far away from the substrate, and the pixel defining layer is provided with a plurality of pixel openings, and the light emitting layer is arranged at the pixel openings; the color film layer comprises a target color filter unit and a black matrix, and the black matrix opposite to the photosensitive element is provided with imaging holes; the shading structure is positioned between the photosensitive element and the target color filter unit and is configured to block a transmission path of target light between the target color filter unit and the photosensitive element, wherein the target light is ambient light which passes through finger fingerprints when a finger of a user touches a fingerprint identification area of the display screen.

Description

Display screen, fingerprint image acquisition method and display device

Technical Field

The disclosure relates to the technical field of display, in particular to a display screen, a fingerprint image acquisition method and a display device.

Background

Fingerprint identification is one of important user authentication modes, and can be applied to the scenes such as fingerprint unlocking, fingerprint payment and the like. Along with the development of fingerprint identification technology, an on-screen fingerprint identification scheme based on the optical fingerprint identification technology is developed, and the scheme enables a pixel circuit and a photosensitive element for fingerprint acquisition to be manufactured on the same substrate, so that the thickness of a display screen with a fingerprint identification function is effectively reduced, the manufacturing cost of the process is also reduced, full-screen fingerprint identification and folding screen fingerprint identification are enabled to be possible, and the on-screen fingerprint identification device has the characteristics of short optical path and high transmittance compared with under-screen fingerprint identification. However, there are still problems with this on-screen fingerprint recognition scheme, such as blurring of fingerprint imaging when using ambient light for fingerprint imaging.

Disclosure of Invention

In view of the above problems, the present disclosure has been made in order to provide a display screen, a fingerprint image acquisition method, and a display device that are advantageous in improving the above problems or at least partially improving the above problems.

In a first aspect, an embodiment of the present disclosure provides a display screen having a fingerprint recognition function, including:

a substrate base;

a photosensitive element disposed on one side of the substrate base plate;

the pixel defining layer is arranged on one side of the photosensitive element, which is far away from the substrate, and is provided with a plurality of pixel openings, and the light emitting layer is arranged at the pixel openings;

the color film layer comprises a target color filter unit and a black matrix, and the black matrix opposite to the photosensitive element is provided with imaging holes;

and the shading structure is positioned between the photosensitive element and the target color filter unit and is configured to block a transmission path of target light between the target color filter unit and the photosensitive element, wherein the target light is ambient light which passes through a finger fingerprint when the finger of a user touches a fingerprint identification area of the display screen.

Further, the light shielding structure includes: and a blocking portion in the pixel defining layer between adjacent pixel openings, the blocking portion being made of a light shielding material to block the target light transmitted from the target color filter unit from being incident on the photosensitive element.

Further, the side wall of the blocking portion has a preset gradient angle, and the preset gradient angle and the thickness of the blocking portion in the direction perpendicular to the substrate are set according to the incident angle of a first reference light ray, wherein the first reference light ray is a light ray which is transmitted from the target color filter unit to the pixel defining layer, the light path is directed to a first critical imaging position of the photosensitive element, and the first critical imaging position is a critical imaging position relatively far away from the target color filter unit.

Further, the display screen further includes: the touch control layer is arranged between the light-emitting layer and the color film layer, and comprises a plurality of first touch control electrodes extending along a first direction and a plurality of second touch control electrodes extending along a second direction, and orthographic projections of the first touch control electrodes and the second touch control electrodes on a substrate are positioned in orthographic projections of the black matrix on the substrate;

the light shielding structure includes: the first touch electrode is configured to block target light transmitted from the target color filter unit from being incident on the photosensitive element.

Further, the wiring width of the first touch electrode and/or the distance between the first touch electrode and the color film layer in the direction vertical to the substrate base plate are set according to the incident angle of the second reference light,

the second reference light is a light ray transmitted from the target color filter unit to the second critical imaging position of the photosensitive element, wherein the light path points to the second critical imaging position of the photosensitive element, and the second critical imaging position is a critical imaging position relatively close to the target color filter unit.

Further, along the direction perpendicular to the substrate, the edge of the first touch electrode is flush with the edge of the corresponding black matrix.

In a second aspect, an embodiment of the present disclosure further provides a display screen with a fingerprint identification function, including:

a substrate base;

the color film layer comprises a target color filter unit and a black matrix;

the fingerprint acquisition module comprises a photosensitive element and a signal acquisition module, wherein the orthographic projection of the photosensitive element on the substrate is positioned in the orthographic projection of the black matrix on the substrate;

the signal acquisition module is connected with the photosensitive element and is configured to: respectively acquiring a first fingerprint image and a second fingerprint image, and performing pixel coordinate adjustment on the first fingerprint image so as to enable the positions of the first fingerprint image and the second fingerprint image to coincide; superposing the adjusted first fingerprint image and second fingerprint image to obtain a target fingerprint image;

The first fingerprint image is an image formed on a photosensitive element on a first side of the target color filter unit, the second fingerprint image is an image formed on a photosensitive element on a second side of the target color filter unit, and the target light is ambient light passing through a finger fingerprint when the finger of a user touches a fingerprint identification area of the display screen.

Further, the light emitting layer includes: red light emitting device, green light emitting device and blue light emitting device, fingerprint acquisition module still includes: the light source is the green light emitting device and the blue light emitting device of fingerprint identification area, the photosensitive element has protruding portion, protruding portion extends towards the interval region between green light emitting device and the blue light emitting device.

In a third aspect, an embodiment of the present disclosure further provides a fingerprint image obtaining method, applied to a display screen having a fingerprint identification function, where the display screen includes: the color filter comprises a substrate, a photosensitive element and a color film layer, wherein the color film layer comprises a target color filter unit and a black matrix; an orthographic projection of the photosensitive element on the substrate is located within an orthographic projection of the black matrix on the substrate, the method comprising:

Respectively acquiring a first fingerprint image and a second fingerprint image in response to fingerprint touch operation of a user, wherein the first fingerprint image is a target light ray transmitted through the target color filter unit, an image is formed on a photosensitive element on the first side of the target color filter unit, the second fingerprint image is a target light ray transmitted through the target color filter unit, an image is formed on a photosensitive element on the second side of the target color filter unit, and the target light ray is ambient light transmitted through a finger fingerprint when the finger of the user touches a fingerprint identification area of the display screen;

performing pixel coordinate adjustment on the first fingerprint image so as to enable the positions of the first fingerprint image and the second fingerprint image to coincide;

and superposing the adjusted first fingerprint image and second fingerprint image to obtain a target fingerprint image.

Further, performing pixel coordinate adjustment on the first fingerprint image so that positions of the first fingerprint image and the second fingerprint image coincide, including:

and carrying out rotation and translation processing on the pixel coordinates of the first fingerprint image so as to enable the pixel coordinates of the first fingerprint image to coincide with the pixel coordinates of the second fingerprint image.

In a fourth aspect, an embodiment of the present disclosure further provides a display apparatus, including: the display screen provided in the first aspect or the second aspect.

The technical scheme provided in the embodiment of the disclosure has at least the following technical effects or advantages:

according to the display screen with the fingerprint identification function, the imaging holes are formed in the black matrix opposite to the photosensitive elements, and the light shielding structure is further arranged on the basis of collecting target light entering from the imaging holes and used for blocking the transmission path of the target light between the target color filter unit and the photosensitive elements. The target light is ambient light which passes through the finger fingerprint when the finger of the user touches the fingerprint identification area of the display screen. Therefore, when the ambient light is used for fingerprint imaging, the problem of fingerprint imaging blurring caused by the target light incident from the target color filter unit can be effectively solved, and the definition of the acquired fingerprint image is improved.

The foregoing description is merely an overview of the technical solutions provided by the embodiments of the present disclosure, and in order to make the technical means of the embodiments of the present disclosure more clear, it may be implemented according to the content of the specification, and in order to make the foregoing and other objects, features and advantages of the embodiments of the present disclosure more understandable, the following specific implementation of the embodiments of the present disclosure will be specifically described below.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures. In the drawings:

FIG. 1 is a schematic cross-sectional view of an exemplary display screen;

FIG. 2 is a schematic diagram of the optical path of ambient light transmitted by a fingerprint;

FIG. 3 is a schematic cross-sectional view of an exemplary display screen in an embodiment of the present disclosure;

FIG. 4 is a schematic view of shielding a target light by a sidewall of a blocking portion according to an embodiment of the disclosure;

FIG. 5 is a schematic diagram of a design of a barrier in an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of shielding a target light by a first touch electrode according to an embodiment of the disclosure;

FIG. 7 is a schematic diagram of a touch electrode design in an embodiment of the disclosure;

FIG. 8 is a schematic cross-sectional view of another exemplary display screen in an embodiment of the present disclosure;

FIG. 9 is an image light path diagram of a target light ray on both sides of a red filter unit according to an embodiment of the present disclosure;

FIG. 10 is an exemplary blended fingerprint image;

FIG. 11 is a diagram of a fingerprint acquired by a left sensor;

FIG. 12 is a graph of a fingerprint acquired by a right sensor;

FIG. 13 is a processed image of a target fingerprint in an embodiment of the present disclosure;

FIG. 14 is a schematic diagram of an arrangement of pixels and photosensors in an embodiment of the disclosure;

fig. 15 is a flowchart of a fingerprint image acquisition method according to an embodiment of the present disclosure.

Detailed Description

The most obvious structural features of the fingerprint are staggered ridge lines and valley lines, wherein the ridge lines are convex parts in the fingerprint texture, and the valley lines are concave parts in the fingerprint texture. For example, using optical fingerprint sensing technology to obtain the fingerprint may include two ways:

first, ambient light is transmitted for imaging. When a finger of a user touches a fingerprint recognition area of the display screen, after the finger is irradiated by ambient light, ridge transmission light (i.e., ambient light transmitted after irradiating the ridge in the finger fingerprint) and Gu Toushe light (i.e., ambient light transmitted after irradiating the valley in the finger fingerprint) are obtained, the light intensities of the ridge transmission light and Gu Toushe light are different, and after the ridge transmission light and Gu Toushe light are collected, a fingerprint image with alternate brightness can be formed according to the ridge transmission light and Gu Toushe light.

Second, light reflection imaging is displayed. And acquiring light reflected after the ridges in the finger fingerprint are irradiated by the display light and light reflected after the valleys in the finger fingerprint are irradiated by the display light, so as to obtain a fingerprint line image with alternate brightness and darkness.

As shown in fig. 1, in some examples, a display screen with an on-screen fingerprinting function may include: a substrate 100, a photosensitive element 102 disposed on one side of the substrate 100, a pixel defining layer 104 disposed on one side of the photosensitive element 102 away from the substrate 100, and a light emitting layer 106, a color film layer 110 disposed on one side of the light emitting layer 106 away from the photosensitive element 102. The light emitting layer 106 is disposed at a pixel opening of the pixel defining layer 104, and the color film layer 110 includes a plurality of color filter units 111 and a black matrix 112 disposed between adjacent color filter units 111.

The orthographic projection of the photosensitive element 102 on the substrate 100 is located within the orthographic projection of the black matrix 112 on the substrate 100. The black matrix 112, which is directly opposite to the photosensor 102, is provided with an opening as an imaging aperture 113 for imaging a fingerprint. The micro-collimation effect is achieved by the size ratio of the photosensitive element 102 to the facing black matrix 112, so that the photosensitive element 102 can receive light rays carrying fingerprint information after being transmitted by ambient light or reflected by display light through the imaging hole 113.

For example, when imaging a fingerprint with ambient light, the ambient light transmitted through the finger may be incident on the photosensor 102 through the imaging aperture 113 to be imaged, resulting in a fingerprint image. However, in the practical application process, the phenomenon of fingerprint imaging blurring is found to be generated under the environment light. In this regard, it was found through practical verification analysis and data verification that the reason for the light mixing is that when fingerprint imaging is performed using ambient light, as shown in fig. 2, a larger portion of the light transmitted through the finger is transmitted from the red filter unit 111a above the light-emitting layer 106 in addition to the light incident on the light-sensitive element 102 from the imaging aperture 113 of the black matrix 112 above the light-sensitive element 102 as intended. Since the ambient light transmitted through the finger is usually red light, the red light can pass through the red filter unit 111a therein, and the spectral transmission is not affected, but the light receiving amount of the portion is high due to the large opening of the red filter unit 111 a. Therefore, when fingerprint imaging is performed using ambient light, images generated by the light transmitted through the red filter unit 111a, which are left and right, occur, resulting in blurring of fingerprint imaging.

In view of this, the embodiments of the present disclosure provide two schemes, one is to image the fingerprint along the imaging hole 113, and shade the transmitted light of the large-angle oblique red filter unit 111 a; the other is to discard the design of opening holes on the black matrix 112 opposite to the photosensitive element 102, and only use the ambient light obliquely incident from the transparent red filter unit 111a to image the fingerprint, and both schemes can effectively improve the imaging blur problem caused by light mixing when imaging the ambient light fingerprint, thereby improving the definition of the acquired fingerprint image.

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It should be noted that, the term "and/or" appearing herein is merely an association relationship describing the association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. The term "plurality" includes two or more than two cases.

An embodiment of the present disclosure provides a display screen with a fingerprint recognition function. For example, the display screen may be a display panel, a smart display screen, or other display product or component having fingerprint recognition functionality.

The display screen includes a plurality of pixel regions, each pixel region including a plurality of sub-pixels, each sub-pixel emitting light of one color, such as one of red light, green light, blue light, and white light. The number and arrangement of the sub-pixels in each pixel region may be set according to actual needs, which is not limited in this embodiment. For example, each pixel region may include three sub-pixels, respectively a red sub-pixel, a green sub-pixel, and a blue sub-pixel. For another example, each pixel region may also include four sub-pixels, respectively: a white subpixel, a red subpixel, a green subpixel, and a blue subpixel; alternatively, respectively: a red sub-pixel, a blue sub-pixel, and two green sub-pixels.

The display screen includes a fingerprint recognition area, which may be located in an active display area (AA area) of the display screen, for example. When the finger of the user touches the fingerprint identification area, the display screen can acquire the fingerprint image of the user, so that the fingerprint identification function is realized.

FIG. 3 illustrates a schematic cross-sectional view of an exemplary display screen. As shown in fig. 3, the display screen 10 may include: the light-shielding structure comprises a substrate 100, a photosensitive element 102, a pixel defining layer 104 (Pixel Define Layer, PDL), a light-emitting layer 106, a color film layer 110 and a light-shielding structure.

For example, the substrate 100 may be a rigid substrate such as a Glass substrate or a PMMA (Polymethyl methacrylate ) substrate, or a flexible substrate such as an Ultra-thin Glass (Ultra-thin Glass), a PET (Polyethylene terephthalate ) substrate, a PEN (Polyethylenenaphthalate two formic acid glycol ester, polyethylene naphthalate) substrate, or a PI (Polyimide) substrate, or the like, which is not limited in this embodiment.

The photosensitive element 102 is disposed on one side of the substrate 100. For example, the photosensor 102 may be an amorphous silicon (a-Si) PIN photodiode, or other device having a function of converting an optical signal into an electrical signal.

It should be noted that, the side of the photosensitive element 102 near the substrate 100 is further provided with a thin film transistor array and related functional film layers such as a buffer layer and/or an insulating layer. For example, the thin film transistor array may include a driving transistor 122 and a photosensitive control transistor 121, the driving transistor 122 being connected to the light emitting device of the corresponding sub-pixel, the photosensitive control transistor 121 being connected to the photosensitive element 102 and configured to control the derivation of the electrical signal converted by the photosensitive element 102. For example, when the photosensitive control transistor 121 is turned on, an electric signal converted from an optical signal collected by the photosensitive element 102 is output through the photosensitive control transistor 121.

In some examples, the photosensitive elements 102 are distributed within the fingerprint identification area. For example, at least one photosensitive element 102 is disposed within each pixel area within the fingerprint identification area. That is, one photosensor 102 may be disposed in each pixel region, or a plurality of photosensors 102 may be disposed in each pixel region, specifically according to actual needs. Of course, in other examples, the photosensitive elements 102 may be disposed in other display areas besides the fingerprint recognition area, which is not limited in this embodiment.

The pixel defining layer 104 is arranged on the side of the photosensitive element 102 remote from the substrate 100. The pixel defining layer 104 has a plurality of pixel openings for defining light emitting regions of the respective sub-pixels.

The light emitting layer 106 is located within the pixel opening and includes a plurality of light emitting devices. Each sub-pixel includes one light emitting device, and the light emitting layer 106 may include a red light emitting device, a blue light emitting device, and a green light emitting device, for example, each pixel region includes a red sub-pixel, a green sub-pixel, and a blue sub-pixel.

The light emitting device may include: the first electrode layer, the light-emitting material layer, and the second electrode layer are stacked, and the first electrode layer and the second electrode layer serve as an anode 103 and a cathode, respectively, and for example, the first electrode layer may be the anode 103 and the second electrode layer may be the cathode. In addition, the light emitting device may further include: functional material layers such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and the like are provided between the anode 103 and the light emitting material layer, and between the cathode and the light emitting material.

The luminescent material used for the luminescent material layer may be of various types. For example, the light emitting material may include an organic material, and in this case, the light emitting device may be an OLED (Organic Light Emitting Diode ) light emitting device. For another example, the light emitting material may include a quantum dot material, and in this case, the light emitting device may be a QLED (Quantum Dot Light Emitting Diodes, quantum dot light emitting diode) light emitting device.

Of course, the display panel further includes a thin film encapsulation layer 130 (Thin Film Encapsulation, TFE), where the thin film encapsulation layer 130 is disposed on a side of the light emitting layer 106 away from the substrate 100, so as to protect the light emitting layer 106 and planarize the light emitting layer.

The color film layer 110 is disposed on a side of the film packaging layer 130 away from the light emitting layer 106, that is, a core (Color filter On Encapsulation, color filter on packaging layer) structure is adopted, so that no additional polarizer is required, and the thickness above the screen is reduced.

The color film layer 110 includes a plurality of color filter units 111 and a black matrix 112. The color filter unit 111 is provided corresponding to the light emitting device. Taking the example that the plurality of light emitting devices includes a red light emitting device, a blue light emitting device and a green light emitting device, the color filter unit 111 correspondingly also includes a red filter unit 111a, a blue filter unit and a green filter unit. The photosensor 102 is disposed corresponding to the black matrix 112, and the black matrix 112 facing the photosensor 102 is provided with imaging holes 113. In fingerprint recognition, light reflected or transmitted by the finger can be incident on the photosensor 102 through the imaging aperture 113 to be imaged.

In a scenario where fingerprint imaging is performed using ambient light, when a user's finger touches a fingerprint recognition area of a display screen, the ambient light that passes through the finger fingerprint is referred to herein as target light. Some of these target light rays may pass through the imaging apertures 113 on the black matrix 112 and be incident on the corresponding photosensitive elements 102 for imaging. Another part may continue into the screen through the color filter unit 111 of the corresponding color. The color filter unit 111 that is capable of transmitting the target light is referred to herein as a target color filter unit. For example, the target light is red light, and the target color filter unit is the color filter unit 111 capable of transmitting red light. Taking the example that the color filter unit 111 includes a red filter unit, a blue filter unit, and a green filter unit, the target color filter unit is a red filter unit. The target color filter unit is mainly taken as a red filter unit for illustration.

The light shielding structure is located between the light sensitive element 102 and the target color filter unit. The light shielding structure is configured to block a transmission path of the target light between the target color filter unit and the photosensitive element 102. Therefore, the target light rays entering from the target color filter unit at a large angle can be shielded, the target light rays penetrating through the target color filter unit are prevented from irradiating the photosensitive element 102, and the imaging hole 113 opposite to the photosensitive element 102 is used for fingerprint imaging, so that the problem of fingerprint imaging blurring caused by light mixing of the target light rays entering from the target color filter unit and the target light rays entering from the imaging hole 113 is solved, and the definition of the acquired fingerprint image is improved.

In some examples, the light shielding structure may include: the blocking portions 1041 in the pixel defining layer 104 between adjacent pixel openings can effectively block the target light transmitted from the target color filter unit from being incident on the photosensitive element 102 by designing the material and the structural parameters of the blocking portions 1041. At this time, the material of the pixel defining layer 104 is a light shielding material, that is, the material of the blocking portion 1041 is a light shielding material. For example, in actual processing, after the anode 103 layer of the light-emitting device is prepared, the pixel defining layer 104 may be prepared on the anode 103 layer using a black light-shielding material, forming the blocking portion 1041 capable of blocking the target light incident at the above-described large angle.

For example, in consideration of the limitation of the processing process of the pixel defining layer 104 and the better blocking of the large-angle target light transmitted from the target color filter unit, the sidewall of the blocking portion 1041 may be a curved surface protruding toward the pixel opening direction. Of course, in other examples, the side wall of the blocking portion 1041 may be an inclined plane or other non-plane, which is not limited in this embodiment.

As shown in fig. 4, the sidewall of the blocking portion 1041 has a preset slope angle, and the target light transmitted from the target color filter unit and incident toward the photosensitive element 102 can be blocked by configuring the slope angle and the thickness of the blocking portion 1041 in the direction perpendicular to the substrate 100.

For example, as shown in fig. 5, the closer the incident position is to the right of the red filter unit 111a, the more easily it is blocked by the blocking portion 1041, and the most easily it is the light incident on the photosensor 102 from the left side that bypasses the blocking portion 1041. It will be appreciated that the photosensitive element 102 has an effective imaging area, i.e. an area where the incident target light can be collected, which has two critical imaging positions with respect to the red filter unit 111a, which are located on both sides of the effective imaging area. Herein, a critical imaging position relatively far from the red filter unit 111a is referred to as a first critical imaging position P1, and a critical imaging position relatively close to the red filter unit 111a is referred to as a second critical imaging position P2.

Thus, there are two critical cases in the optical path that can be irradiated onto the photosensor 102, among the target light rays incident on the pixel defining layer 104 at a large angle from the first incident position of the red filter unit 111 a: one is directed to a first critical imaging position P1 of the photosensitive element 102, such as ray 2 in fig. 5, and the other is directed to a second critical imaging position P2 of the photosensitive element 102, such as ray 1 in fig. 5. The first light incident position is a critical light incident position near one side of the corresponding photosensitive element 102.

In some examples, considering that when the display screen also has a touch function, the touch layer 140 also has a certain shielding of the target light, assuming that the touch layer 140 has a shielding function of h0 micrometers, for the photosensor 102 located on the left side of the red filter unit 111a, the first light entering position is located at the Q1 point in fig. 5, considering the shielding of the touch layer 140. At this time, for the target light rays incident from the left side of the red filter unit 111a and not blocked by the touch layer 140, the incident angles may be calculated by respectively:

for ray 1, the angle of incidence a may be by: a=arctan (b/(h-h 0)) where b denotes a distance between the opening of the black matrix 112 corresponding to the red filter unit 111a and the imaging hole 113 in the first direction (i.e., x direction in the drawing), and h denotes a distance between the anode 103 and the black matrix 112 in the direction perpendicular to the substrate 100 (i.e., z direction in the drawing).

For ray 2, the angle of incidence B may be by: b=arctan ((b+k)/(h-h 0)), where k represents the effective imaging plane width of the photosensor 102 in the first direction. It is considered that the blocking portion 1041 only needs to block the light 2, so as to block the target light having a large angle incident toward the photosensor 102.

That is, the above-described light ray 2 may be used as the first reference light ray. The sidewall slope angle of the blocking portion 1041 and the thickness of the blocking portion 1041 may be set according to the incident angle B of the light ray 2, that is, determined according to B, k, h, and h 0.

For example, if the thickness of the touch metal layer is 6500 angstroms and the distance between the touch metal layer and the black matrix 112 is 3000 angstroms along the direction perpendicular to the substrate 100, it can be considered that the touch metal layer has a shielding function of 1 micrometer, h0=1 micrometer, h=15 micrometers, b=13.5 micrometers, and k=6 micrometers, and the incident angle of the light 2 is arctan (19.5/14) =54 °. At this time, the slope angle C of the sidewall of the blocking portion 1041 may be set to 60 °, and the thickness of the blocking portion 1041 may be set to 7 μm. Of course, the setting of the slope angle and the thickness can also float within an acceptable error range, and the fingerprint imaging quality requirement which needs to be met can be met.

In some examples, the display screen further includes: the touch layer 140 makes the display screen have a touch function. The touch layer 140 is disposed between the light emitting layer 106 and the color film layer 110, and may specifically be disposed between the packaging layer and the color film layer 110.

The touch layer 140 includes a plurality of first touch electrodes 141 extending along a first direction and a plurality of second touch electrodes 142 extending along a second direction. The first direction intersects the second direction. For example, the first direction is the x-direction of the display screen and the second direction is the y-direction of the display screen. The orthographic projections of the first touch electrode 141 and the second touch electrode 142 on the substrate 100 are located in the orthographic projection of the black matrix 112 on the substrate 100, and the first touch electrode 141 and the second touch electrode 142 are insulated from each other.

At this time, the light shielding structure may include: the first touch electrode 141 is described above. As shown in fig. 6, in addition to providing a touch function, the first touch electrode 141 is configured to block the target light transmitted from the target color filter unit from being incident on the photosensitive element 102.

For example, on the basis of meeting the design requirement of the touch function, the first touch electrode 141 may be widened, and/or the distance between the first touch electrode 141 and the color film layer 110 along the direction perpendicular to the substrate 100 may be increased to block the large-angle target light that passes through the target color filter unit and is incident toward the photosensitive element 102.

In some examples, the routing of the first touch electrode 141 may be widened such that an edge of the first touch electrode 141 is flush with an edge of the corresponding black matrix 112 in a direction perpendicular to the substrate 100 to better block the target light incident at a large angle.

For example, as shown in fig. 7, when the first touch electrode 141 is designed to block the target light, only the target light transmitted from the second light incident position of the red filter unit 111a and possibly irradiated to the photosensitive element 102 needs to be blocked, so that the target light having a large angle and being incident to the photosensitive element 102 can be blocked. The second light incident position is a critical light incident position far from one side of the corresponding photosensitive element 102, such as a Q2 position located on the right side of the red filter unit 111a in fig. 7.

At this time, for the light ray 3 and the light ray 4 incident from the second light incident position toward the first critical imaging position P1 and the second critical imaging position P2 of the corresponding photosensor 102, the incident angle can be calculated as follows:

the angle of incidence A1 of the light ray 3 can be expressed by the formula: a1 =arctan (B1/h), the incident angle B1 of the light ray 4 can be obtained by the formula: b1 Obtained by =arctan (b 2/h). Wherein b1 is a distance between the second incident light position and the second critical imaging position P2 along the first direction, i.e., the x direction in the figure; b2 is the distance between the second incident light position and the first critical imaging position P1 along the first direction, i.e. the x-direction in the figure.

Then, the target light of the angle A1 is shielded, and the shielding of the target light of the large angle can be realized. That is, the light ray 3 may be used as the second reference light ray, and the wiring width of the first touch electrode 141 and/or the distance between the first touch electrode 141 and the color film layer 110 in the direction perpendicular to the substrate 100 may be set according to the incident angle of the light ray 3, that is, according to the above-mentioned b1 and h.

For example, if the opening size b11 of the black matrix 112 corresponding to the red filter unit 111a is: 33.5 micrometers, the width b12 of the black matrix 112 between the opening of the black matrix 112 and the imaging aperture 113 is 13.5 micrometers, k is 6 micrometers, h1 is 15 micrometers, b1=b11+b12=47 micrometers, b2=b1+k=53 micrometers. Then A1 is 72 ° and B1 is 74 °. At this time, the wiring of the first touch electrode 141 may be widened to be flush with the corresponding black matrix 112, and the distance D between the first touch electrode 141 and the color film layer 110 in the direction perpendicular to the substrate 100 may be set to be 10.7 micrometers, so as to realize shielding of the large-angle target light incident from the red filter unit 111a in case of satisfying the touch function.

For example, the distance between the first touch electrode 141 and the color film layer 110 may be adjusted in the direction perpendicular to the substrate 100, for example, the distance D between the first touch electrode 141 and the color film layer 110 in the direction perpendicular to the substrate 100 may be increased by moving the bottom surface of the first touch electrode 141 downward, so as to increase the shielding of the target light incident at a large angle.

It should be noted that the light shielding structure may include: the blocking portion 1041 and/or the first touch electrode 141. That is, both schemes can realize shielding of the large-angle target light incident from the target color filter unit, and both schemes can be applied to the product alone or together, which is not limited in this embodiment.

Of course, the display screen may further include other structures besides the above structure, for example, a cover layer (not shown in the drawings) disposed on a side of the color film layer 110 away from the substrate 100, for protecting the color film layer 110, which may be referred to in the related art.

According to the embodiment of the disclosure, the original hierarchical structure in the display screen is improved, so that the large-angle target light transmitted by the target color filter unit can be shielded, the problem of fingerprint imaging blurring caused by incidence of the target light to the photosensitive element 102 is solved, and the definition of the acquired fingerprint image is improved.

An embodiment of the present disclosure further provides a display screen with a fingerprint recognition function, for example, the display screen may be a display panel, an intelligent display screen, or other display products or components with a fingerprint recognition function. As shown in fig. 8, the display 20 includes: the fingerprint sensor comprises a substrate 100, a pixel defining layer 104, a light emitting layer 106, a color film layer 110 and a fingerprint acquisition module.

The color film layer 110 includes a plurality of color filter units 111 and a black matrix 112. Among the plurality of color filter units 111, the color filter unit 111 that transmits the target light is referred to as a target color filter unit.

The fingerprint acquisition module includes: the photosensor 102 and the signal acquisition module. The orthographic projection of the photosensitive element 102 on the substrate 100 is located within the orthographic projection of the black matrix 112 on said substrate 100. Unlike the embodiment provided above, the black matrix 112 facing the photosensor 102 in this embodiment is not provided with the above-described imaging holes 113. At this time, when fingerprint imaging is performed using ambient light, fingerprint imaging light comes from target light incident at a large angle after passing through the target color filter unit. The target light transmitted through the target color filter unit is respectively irradiated to the photosensitive elements 102 on both sides for fingerprint imaging.

For example, as shown in fig. 9, after the target light carrying fingerprint information passes through the red filter unit 111a, the target light is imaged on both the photosensitive elements 102a and 102b on the left and right sides, so that two overlapping images exist in the acquired fingerprint image, as shown in fig. 10. The light signals collected by the photosensors 102a, 102b on the left and right sides of the red filter unit 111a are extracted as separate fingerprint patterns, fig. 11 shows the fingerprint pattern collected by the left photosensor 102a, and fig. 12 shows the fingerprint pattern collected by the right photosensor 102 b. Comparing fig. 11 and 12, it is found that the images formed on both sides are identical, but there is a positional deviation in the imaging position, so that the two images are overlapped in a staggered manner, that is, there is a ghost problem, and the definition of the fingerprint image is affected.

Therefore, the two-dimensional fingerprint image acquisition device can be used for carrying out coordinate conversion according to the relative position relation of the two-dimensional images and then overlapping, on one hand, the imaging blurring problem caused by the misplaced images can be solved, on the other hand, the signal quantity after brightness overlapping is twice that of a single fingerprint image, and the signal-to-noise ratio of the acquired fingerprint image can be effectively improved, so that a clearer fingerprint image is obtained.

Based on this, the image formed on the photosensitive element on the first side of the target color filter unit by the target light transmitted through the target color filter unit is referred to herein as a first fingerprint image, and the image formed on the photosensitive element on the second side of the target color filter unit by the target light transmitted through the target color filter unit is referred to herein as a second fingerprint image. The first side and the second side are opposite sides, for example, if the first side is the left side in fig. 9, the second side is the right side in fig. 9, and if the first side is the right side in fig. 9, the second side is the left side in fig. 9, which is not limited in this embodiment.

The signal acquisition module is connected to the photosensitive element 102 and configured to: acquiring a first fingerprint image and a second fingerprint image, and then, performing pixel coordinate adjustment on the first fingerprint image so as to enable the positions of the first fingerprint image and the second fingerprint image to coincide; and then, superposing the adjusted first fingerprint image and the second fingerprint image to obtain a target fingerprint image.

In the implementation, the signals collected by the photosensitive elements on the first side of each target color filter unit and the signals collected by the photosensitive elements on the second side of each target color filter unit can be obtained respectively. The signals collected by the photosensitive elements on the first side are spliced to obtain the first fingerprint image, and the signals collected by the photosensitive elements on the second side are spliced to obtain the second fingerprint image.

After the first fingerprint image and the second fingerprint image are obtained, the first fingerprint image and the second fingerprint image which are dislocated can be subjected to position correction. For example, the positional relationship of the two may be predetermined and configured, and then the pixel coordinates of the first fingerprint image are rotated and translated according to the preset positional relationship so that the positions of the first fingerprint image and the second fingerprint image coincide. For example, the preset positional relationship may include: and the rotation matrix and the translation matrix are used for adjusting the pixel coordinates of the first fingerprint image according to the rotation matrix and the translation matrix, and the pixel coordinates of the first fingerprint image can be overlapped with the pixel coordinates of the second fingerprint image.

After the position adjustment is completed, the pixel value of the first fingerprint image and the pixel value of the second fingerprint image can be overlapped to obtain the target fingerprint image. That is, for each pixel, the pixel value of the first fingerprint image is overlapped with the pixel value of the second fingerprint image, and the overlapped pixel value is used as the pixel value of the pixel in the target fingerprint image, so that the signal-to-noise ratio of the ambient light fingerprint image is effectively improved. For example, as shown in fig. 13, the target fingerprint image obtained by converting and superimposing the coordinates shown in fig. 11 and 12 has effectively improved sharpness compared to the image shown in fig. 10.

On the basis, in order to ensure that a fingerprint image can still be formed under low ambient light, the display screen provided by the embodiment of the disclosure also has a display light imaging function. When the brightness of the environment is detected to be lower than a preset threshold value, the environment brightness is judged to be too low, and a display light fingerprint imaging mode is started, namely fingerprint imaging is carried out by utilizing light reflected by display light irradiation on the fingerprint.

At this time, the fingerprint acquisition module further comprises a light source. For example, a portion of the light emitting devices distributed over the fingerprint recognition area may be multiplexed as a light source for displaying an optical fingerprint image. In some examples, the light emitting layer 106 includes: red light emitting device, green light emitting device, and blue light emitting device. Considering that the ambient light transmitted through the finger is usually red light, a green light emitting device and a blue light emitting device of the fingerprint recognition area may be multiplexed as a light source for displaying the optical fingerprint image so as to suppress the influence of the ambient light. Accordingly, fingerprint imaging can be performed using fingerprint reflected light transmitted from the blue filter unit and the green filter unit.

Further, as shown in fig. 14, the photosensor 102 also has a projection 1021, which projection 1021 extends toward the interval region between the green light emitting device and the blue light emitting device, away from the red filter unit 111a. The shape and area of the protruding portion 1021 may be set according to practical needs, for example, the shape may be square, for example, a region of 6 microns by 6 microns or 10 microns by 10 microns is added, or the shape may be circular, which is not limited in this embodiment.

For example, as shown in fig. 14, each pixel region 200 of the display panel may include one red subpixel R, two green subpixels G, and one blue subpixel B. Each pixel region 200 may be provided with one photosensor 102, and the photosensor 102 may be disposed between the red and blue subpixels R and B. That is, the photosensor 102 is disposed opposite to the black matrix 112 between the red and blue sub-pixels R and B. The photosensor 102 may be provided with the above-described protrusion 1021 between the upper green sub-pixel G and the blue sub-pixel B (as shown in fig. 14), or may be provided with the above-described protrusion 1021 between the lower green sub-pixel G and the blue sub-pixel B, or may be provided with the above-described protrusion 1021 between the two green sub-pixels G and the blue sub-pixel B, respectively, which is not limited in this embodiment.

By increasing the area of the photosensitive element 102 and increasing this area between the blue sub-pixel B and the green sub-pixel G, the small area of the imaging area can be made to form a microcollimator effect with the blue filter element and the green filter element. Therefore, the display light intensity can be utilized to a large extent, the light effect of fingerprint reflection is improved, the influence of ambient light is restrained, and a clear fingerprint image is formed.

In addition, an embodiment of the disclosure further provides a fingerprint image acquisition method applied to the display screen with the fingerprint identification function. The display screen includes: the substrate 100, the photosensitive element 102, the light emitting layer 106 and the color film layer 110, wherein the color film layer 110 comprises a target color filter unit and a black matrix 112; the orthographic projection of the photosensitive element 102 on the substrate 100 is located within the orthographic projection of the black matrix 112 on the substrate 100. The specific structure may be referred to the related description in the above embodiment, and will not be described herein. As shown in fig. 15, the method may include:

step S101, respectively acquiring a first fingerprint image and a second fingerprint image in response to fingerprint touch operation of a user;

step S102, pixel coordinate adjustment is carried out on a first fingerprint image so that the positions of the first fingerprint image and a second fingerprint image coincide;

step S103, overlapping the adjusted first fingerprint image and the second fingerprint image to obtain a target fingerprint image.

The first fingerprint image is the target light transmitted through the target color filter unit, the image is formed on the photosensitive element at the first side of the target color filter unit, and the second fingerprint image is the target light transmitted through the target color filter unit, and the image is formed on the photosensitive element at the second side of the target color filter unit. The target light is ambient light that passes through the finger print when the user's finger touches the fingerprint recognition area of the display screen.

It should be noted that, the specific implementation process of step S101 to step S103 may refer to the related description in the above embodiment, and will not be repeated here.

In some examples, performing pixel coordinate adjustment on the first fingerprint image such that the positions of the first fingerprint image and the second fingerprint image coincide may include: and performing rotation and translation processing on pixel coordinates of the first fingerprint image so that the positions of the first fingerprint image and the second fingerprint image coincide. Specific implementation processes may refer to the related descriptions in the above embodiments, and are not repeated here.

In addition, an embodiment of the present disclosure further provides a display apparatus, including: any one of the embodiments above provides a display screen. For example, the display device may be any product or component with display function, such as a mobile phone, a notebook computer, a tablet computer, a display, a television, a digital photo frame, etc.

It should be noted that, each embodiment provided in the present disclosure is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.

In the above description, technical details such as patterning of the respective layers of the product are not described in detail. Those skilled in the art will appreciate that layers, regions, etc. of the desired shape may be formed by a variety of techniques. In addition, to form the same structure, those skilled in the art can also devise methods that are not exactly the same as those described above. Although the embodiments are described above separately, this does not mean that the measures in the embodiments cannot be used advantageously in combination.

In addition, one of ordinary skill in the art will appreciate that: the discussion of any of the embodiments above is merely exemplary and is not intended to suggest that the scope of the disclosure is limited to these examples; combinations of features of the above embodiments or in different embodiments are also possible within the spirit of the present disclosure, steps may be implemented in any order, and there are many other variations of the different aspects of one or more embodiments of the present disclosure as described above, which are not provided in detail for the sake of brevity.

While the preferred embodiments of the present disclosure have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the disclosure.

Claims (11)

1. A display screen with fingerprint identification function, characterized by comprising:

a substrate base;

a photosensitive element disposed on one side of the substrate base plate;

the pixel defining layer is arranged on one side of the photosensitive element, which is far away from the substrate, and is provided with a plurality of pixel openings, and the light emitting layer is arranged at the pixel openings;

The color film layer comprises a target color filter unit and a black matrix, and the black matrix opposite to the photosensitive element is provided with imaging holes;

and the shading structure is positioned between the photosensitive element and the target color filter unit and is configured to block a transmission path of target light between the target color filter unit and the photosensitive element, wherein the target light is ambient light which passes through a finger fingerprint when the finger of a user touches a fingerprint identification area of the display screen.

2. The display screen of claim 1, wherein the light shielding structure comprises: and a blocking portion in the pixel defining layer between adjacent pixel openings, the blocking portion being made of a light shielding material to block the target light transmitted from the target color filter unit from being incident on the photosensitive element.

3. The display screen according to claim 2, wherein a sidewall of the blocking portion has a preset slope angle, and a thickness of the blocking portion in a direction perpendicular to the substrate is set according to an incident angle of a first reference light ray, wherein the first reference light ray is a target light ray transmitted from the target color filter unit to the pixel defining layer, and an optical path is directed to a first critical imaging position of the photosensitive element, the first critical imaging position being a critical imaging position relatively distant from the target color filter unit.

4. The display screen of claim 1, further comprising:

the touch control layer is arranged between the light-emitting layer and the color film layer, and comprises a plurality of first touch control electrodes extending along a first direction and a plurality of second touch control electrodes extending along a second direction, and orthographic projections of the first touch control electrodes and the second touch control electrodes on a substrate are positioned in orthographic projections of the black matrix on the substrate;

the light shielding structure includes: the first touch electrode is configured to block target light transmitted from the target color filter unit from being incident on the photosensitive element.

5. The display screen of claim 4, wherein the wiring width of the first touch electrode and/or the distance between the first touch electrode and the color film layer in the direction perpendicular to the substrate is set according to the incident angle of the second reference light,

the second reference light is a light ray transmitted from the target color filter unit to the second critical imaging position of the photosensitive element, wherein the light path points to the second critical imaging position of the photosensitive element, and the second critical imaging position is a critical imaging position relatively close to the target color filter unit.

6. The display screen of claim 4, wherein an edge of the first touch electrode is flush with an edge of the corresponding black matrix in a direction perpendicular to the substrate base plate.

7. A display screen with fingerprint identification function, characterized by comprising:

a substrate base;

the color film layer comprises a target color filter unit and a black matrix;

the fingerprint acquisition module comprises a photosensitive element and a signal acquisition module, wherein the orthographic projection of the photosensitive element on the substrate is positioned in the orthographic projection of the black matrix on the substrate;

the signal acquisition module is connected with the photosensitive element and is configured to: respectively acquiring a first fingerprint image and a second fingerprint image, and performing pixel coordinate adjustment on the first fingerprint image so as to enable the positions of the first fingerprint image and the second fingerprint image to coincide; superposing the adjusted first fingerprint image and second fingerprint image to obtain a target fingerprint image;

the first fingerprint image is an image formed on a photosensitive element on a first side of the target color filter unit, the second fingerprint image is an image formed on a photosensitive element on a second side of the target color filter unit, and the target light is ambient light passing through a finger fingerprint when the finger of a user touches a fingerprint identification area of the display screen.

8. The display screen of claim 7, wherein the light emitting layer comprises: red light emitting device, green light emitting device and blue light emitting device, fingerprint acquisition module still includes: the light source is the green light emitting device and the blue light emitting device of fingerprint identification area, the photosensitive element has protruding portion, protruding portion extends towards the interval region between green light emitting device and the blue light emitting device.

9. A fingerprint image acquisition method, applied to a display screen with fingerprint identification function, the display screen comprising: the color filter comprises a substrate, a photosensitive element and a color film layer, wherein the color film layer comprises a target color filter unit and a black matrix; an orthographic projection of the photosensitive element on the substrate is located within an orthographic projection of the black matrix on the substrate, the method comprising:

respectively acquiring a first fingerprint image and a second fingerprint image in response to fingerprint touch operation of a user, wherein the first fingerprint image is a target light ray transmitted through the target color filter unit, an image is formed on a photosensitive element on the first side of the target color filter unit, the second fingerprint image is a target light ray transmitted through the target color filter unit, an image is formed on a photosensitive element on the second side of the target color filter unit, and the target light ray is ambient light transmitted through a finger fingerprint when the finger of the user touches a fingerprint identification area of the display screen;

Performing pixel coordinate adjustment on the first fingerprint image so as to enable the positions of the first fingerprint image and the second fingerprint image to coincide;

and superposing the adjusted first fingerprint image and second fingerprint image to obtain a target fingerprint image.

10. The method of claim 9, wherein performing pixel coordinate adjustment on the first fingerprint image such that the positions of the first fingerprint image and the second fingerprint image coincide comprises:

and carrying out rotation and translation processing on pixel coordinates of the first fingerprint image so as to enable the positions of the first fingerprint image and the second fingerprint image to coincide.

11. A display device, comprising: the display screen of any one of claims 1-8.

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