Under-screen light sensing module, manufacturing method thereof, and display device

Abstract

The present application discloses an under-screen light sensing module, a preparation method thereof, and a display device, comprising: a display panel, the display panel comprising a base substrate and a plurality of sub-pixel units arranged in an array on the base substrate; a photosensitive layer arranged on the display panel, the photosensitive layer being used to capture external images, the photosensitive layer comprising a plurality of photosensitive elements arranged in an array, the orthographic projections of the photosensitive elements on the base substrate not overlapping with the orthographic projections of the sub-pixel units on the base substrate. A CMOS photosensitive element array is arranged on the photosensitive layer, and the photosensitive layer is arranged above the display panel, eliminating the front lens structure in the prior art, thereby achieving the effect of allowing the screen to form a front-facing image; the photosensitive elements are arranged in the gap between sub-pixels to prevent the photosensitive elements from affecting the display of the display panel; this arrangement of the photosensitive elements does not affect the sub-pixel arrangement of the display panel, and can achieve a high PPI.

Description

Technical Field

[0001] The present application generally relates to the field of display technology, and specifically relates to an under-screen light sensing module, a preparation method thereof, and a display device. Background Art

[0002] To meet the need for video recording, electronic devices, including mobile phones, typically include camera functionality. To this end, existing mobile devices typically feature front and rear camera modules, with the front camera module typically located on the same side of the display screen for user selfies and other functions. However, as the screen-to-body ratio continues to increase, the requirements for the placement of the front camera are also becoming increasingly stringent.

[0003] Although under-screen cameras can increase the screen-to-body ratio, existing under-screen cameras still have some shortcomings. For example, the screen manufacturing cost is high; the camera image quality is poor, and there are still pixels above the camera blocking the low beam; due to differences in wiring and line resistance in the hole area, there are differences in the display of the hole area and other areas, and there are varying degrees of panel mura defects. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide an under-screen light sensing module and its preparation method, and a display device, which can eliminate the front camera in the existing structure, narrow the frame, and improve the display effect.

[0005] In a first aspect, the present application provides an under-screen light sensing module, comprising:

[0006] A display panel, comprising a base substrate and a plurality of sub-pixel units arranged in an array on the base substrate;

[0007] A photosensitive layer is provided on the display panel, and is used to capture external images. The photosensitive layer includes a plurality of photosensitive elements arranged in an array, and the orthographic projection of the photosensitive elements on the base substrate does not overlap with the orthographic projection of the sub-pixel unit on the base substrate.

[0008] Optionally, the photosensitive layer includes an insulating layer arranged on the side of the sub-pixel unit away from the base substrate, the insulating layer is provided with a receiving groove, the orthographic projection of the receiving groove on the base substrate does not overlap with the orthographic projection of the sub-pixel unit on the base substrate, and the photosensitive element is located inside the receiving groove.

[0009] Optionally, the sidewalls and the bottom surface of the accommodating groove are covered with a light-shielding layer, and the light-shielding layer is located between the photosensitive element and the insulating layer.

[0010] Optionally, the photosensitive element includes a plurality of color photosensitive sub-elements arranged in an array on the photosensitive layer, and the color photosensitive sub-elements include a photosensitive sensor and a color resist block arranged on the photosensitive sensor.

[0011] Optionally, the plurality of color photosensitive sub-elements arrayed on the photosensitive layer form a plurality of photosensitive rows arrayed along a first direction and a plurality of photosensitive columns arrayed along a second direction;

[0012] The plurality of sub-pixel units arranged in an array on the display panel form a plurality of pixel rows arranged in an array along a first direction and a plurality of pixel columns arranged in an array along a second direction.

[0013] Optionally, each of the color photosensitive sub-elements is arranged inside one of the accommodating grooves, each of the color photosensitive sub-elements corresponds to one of the color resist blocks, the edge of the color resist block contacts the light-shielding layer, and the upper surface of the color resist block is flush with the upper surface of the insulating layer.

[0014] Optionally, the color photosensitive element further includes a lens arranged on the side of the color block away from the base substrate, the lens is arranged in a one-to-one correspondence with the photosensitive sensor, and the orthographic projection of the center of the lens on the base substrate overlaps with the orthographic projection of the center of the photosensitive sensor on the base substrate.

[0015] Optionally, the photosensitive layer includes a transparent protective layer arranged on a side of the insulating layer away from the substrate, and the lens is arranged inside the transparent protective layer.

[0016] Optionally, the photosensor includes a photosensitive layer and a photosensitive circuit layer located on a side of the photosensitive layer close to the base substrate, and a photosensitive circuit electrically connected to the photosensitive layer is provided on the photosensitive circuit layer.

[0017] Optionally, the photosensitive circuit layer includes multiple data voltage lines arranged along the first direction and multiple gate control lines arranged along the second direction, one of the data voltage lines is connected to the photosensitive circuit located in the same photosensitive column, and one of the gate control lines is connected to the photosensitive circuit located in the same photosensitive row.

[0018] In a second aspect, the present application provides a method for preparing an under-screen light sensing module, for preparing any of the above under-screen light sensing modules, the method comprising:

[0019] forming a display panel, the display panel comprising a base substrate and a plurality of sub-pixel units arranged in an array on the base substrate;

[0020] A photosensitive layer is formed on the display panel, and the photosensitive layer is used to capture external images. The photosensitive layer includes a plurality of photosensitive elements arranged in an array, and the orthographic projections of the photosensitive elements on the base substrate do not overlap with the orthographic projections of the sub-pixel units on the base substrate.

[0021] In a third aspect, the present application provides a display device comprising an under-screen light sensing module as described above.

[0022] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0023] The under-screen light sensing module, preparation method thereof, and display device provided in the embodiments of the present application adopt a CMOS photosensitive element array to be set on the photosensitive layer, and the photosensitive layer is arranged above the display panel, eliminating the front lens structure in the prior art, so as to achieve the effect of allowing the screen to form a front imaging; the photosensitive elements are arranged in the gap between sub-pixels to prevent the photosensitive elements from affecting the display of the display panel; this arrangement of the photosensitive elements will not affect the sub-pixel arrangement of the display panel, and can achieve high PPI. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0025] Figure 1 A schematic diagram of the arrangement of sub-pixels of a display panel in an under-screen camera;

[0026] Figure 2 A schematic structural diagram of an under-screen light sensing module provided in an embodiment of the present application;

[0027] Figure 3 A top view of an under-screen light sensor module provided in an embodiment of the present application;

[0028] Figure 4 A schematic structural diagram of a display panel provided in an embodiment of the present application;

[0029] Figure 5 A schematic structural diagram of a photosensitive element provided in an embodiment of the present application;

[0030] Figure 6 An optical principle diagram of a pinhole optical fingerprint imaging provided by an embodiment of the present application;

[0031] Figure 7 A schematic structural diagram of a photosensor provided in an embodiment of the present application;

[0032] Figure 8A schematic diagram of a driving circuit of a photosensor provided in an embodiment of the present application;

[0033] Figure 9 A schematic structural diagram of a photosensitive circuit layer provided in an embodiment of the present application;

[0034] Figure 10 A schematic diagram of a photosensitive circuit layer routing method provided in an embodiment of the present application;

[0035] Figure 11 A flowchart of a method for preparing an under-screen light sensing module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0037] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0038] In the prior art, the under-screen camera utilizes a screen, such as an AMOLED (Active-matrix Organic Light-emitting Diode) screen, which has a certain transmittance. The camera is set under the screen. In order to enable the opening area D1 to display the image, and the photosensitive element can also receive the incident light from the outside of the display panel through the opening area D1 of the display panel, the pixel density (such as Figure 1 (I)) is lower than the pixel density of other normal areas D2 (as shown in Figure 1 (II) Although this method increases the transmittance of the aperture area D1, due to the difference in wiring and line resistance in the aperture area D1, the display of the aperture area D1 and other areas D2 are different, and both areas have different degrees of panel mura defects.

[0039] This application proposes an under-screen light sensing module that eliminates the existing under-screen camera. Please see Figure 2-3 ,include:

[0040] A display panel 100 includes a base substrate 11 and a plurality of sub-pixel units P arranged in an array on the base substrate 11;

[0041] A photosensitive layer 200 is provided on the display panel 100, and the photosensitive layer 200 is used to capture external images. The photosensitive layer 200 includes a plurality of photosensitive elements 1 arranged in an array, and the orthographic projection of the photosensitive element 1 on the base substrate 11 does not overlap with the orthographic projection of the sub-pixel unit P on the base substrate 11.

[0042] Photosensitive element 1 is a device that converts light signals into electrical signals and is a key component of a digital camera. Depending on the component, it can be divided into two categories: CCD (Charge Coupled Device) and CMOS (Complementary Metal Oxide Semiconductor). CMOS image sensors have lower power consumption than traditional CCD sensors. In the embodiments of this application, the photosensitive element 1 is described as a CMOS image sensor.

[0043] In the embodiment of the present application, an array of CMOS photosensitive elements 1 is set on the photosensitive layer 200, and the photosensitive layer 200 is arranged above the display panel 100, eliminating the front lens structure in the prior art, so as to achieve the effect of allowing the screen to form a front imaging; the photosensitive elements 1 are arranged in the gap between sub-pixels to prevent the photosensitive elements 1 from affecting the display of the display panel 100; this arrangement of the photosensitive elements 1 will not affect the sub-pixel arrangement of the display panel 100, can achieve high PPI (pixel density), will not affect the picture display of the display panel 100, is conducive to ensuring the aperture ratio of the display panel 100, and ensures a good display effect of the display screen.

[0044] In the embodiment of the present application, the photosensitive layer 200 includes an insulating layer 201 disposed on a side of the sub-pixel unit P away from the base substrate 11. The insulating layer 201 is provided with a receiving groove 202. The orthographic projection of the receiving groove 202 on the base substrate 11 does not overlap with the orthographic projection of the sub-pixel unit P on the base substrate 11. The photosensitive element 1 is located within the receiving groove 202. The sidewalls and bottom surface of the receiving groove 202 are covered with a light shielding layer 211, and the light shielding layer 211 is located between the photosensitive element 1 and the insulating layer 201.

[0045] It should be noted that the shape of the receiving groove 202 is not limited in the embodiment of the present application. The cross-sectional shape of the receiving groove 202 in the direction parallel to the base substrate 11 can be circular, elliptical, trapezoidal, etc. The cross-sectional shape of the receiving groove 202 in the direction perpendicular to the base substrate 11 can be trapezoidal, square, etc.

[0046] In this embodiment, the light shielding layer 211 can completely cover the sidewalls and bottom surface of the receiving groove 202. This design can better suppress stray light caused by the refraction and reflection effects of the microstructures (such as the light-emitting structure and its driving structure) within the display screen, especially the impact of the light-emitting structure within the display screen on the photosensitive element 1, thereby improving imaging accuracy. In this embodiment of the present application, the orthographic projection of the light shielding layer 211 on the base substrate 11 does not overlap with the orthographic projection of the sub-pixel unit P on the base substrate 11, thereby preventing the transmittance of the display panel 100 from being affected, thereby affecting the display quality.

[0047] The display panel 100 in the embodiment of the present application can be an active light-emitting display panel 100, such as an organic light emitting diode (OLED) display panel 100, an active-matrix organic light emitting diode (AMOLED) display panel 100, a passive-matrix organic light emitting diode (Passive Matrix OLED) display panel 100, a quantum dot organic light emitting diode (QLED) display panel 100, etc.

[0048] The display panel 100 of the embodiment of the present application can also be a liquid crystal display panel 100. The present application does not limit the type of the display panel 100. It can be a vertical electric field type liquid crystal display panel 100, such as a twisted nematic (TN) type liquid crystal display panel 100, a multi-domain vertical alignment (MVA) type liquid crystal display panel 100, or a horizontal electric field type liquid crystal display panel 100, such as a fringe field switching (FFS) type liquid crystal display panel 100 or an in-plane switching (IPS) type liquid crystal display panel 100.

[0049] In the embodiment of the present application, the display panel 100 is taken as an OLED display panel 100 for example. Figure 4 As shown, the display panel 100 includes a pixel driving circuit layer 12 , a pixel defining layer 13 (PDL), an organic light emitting element 14 , and an encapsulation layer 15 , which are disposed on a base substrate 11 .

[0050] The organic light-emitting element 14 includes an anode 108, a cathode 109, and an organic light-emitting layer located therebetween. The anode 108 is electrically connected to the pixel drive circuit layer 12. The pixel drive circuit layer 12 includes pixel drive circuits, gate lines, data voltage lines (Vdd), power lines, and other components for driving the organic light-emitting element 14. Typically, the pixel drive circuit for each sub-pixel includes a drive transistor, a switching transistor, a capacitor, and other components, and is electrically connected to the corresponding gate line, data voltage line (Vdd), and power line.

[0051] The pixel defining layer 13 is used to separate adjacent organic light-emitting layers to prevent color crosstalk. Openings are formed in the pixel defining layer 13 to divide it into a pixel opening region and a pixel spacing region. The pixel opening region exposes the anode 108 of the organic light-emitting element 14. The organic light-emitting layer is formed in the pixel region of the pixel defining layer 13 and on the anode 108.

[0052] The pixel driving circuit layer 12 includes, for example, a conventional OLED pixel driving circuit, such as a 2T1C / 3T1C / 7T1C circuit. One of the TFTs is a switching transistor; the other TFT is a driving transistor, electrically connected to the organic light emitting element 14. For clarity, Figure 4 Only the structure of the driving transistor is shown. In this embodiment, the driving transistor is a top-gate structure. In other embodiments, the driving transistor may also be a bottom-gate structure. Figure 4 As shown, the top-gate driving transistor includes an active layer 103, a gate insulating layer 104, a gate layer 105, an interlayer dielectric layer 106 (ILD), and a source-drain metal layer 107, which are stacked in sequence. The source or drain of the driving transistor is electrically connected to the anode 108 of the organic light-emitting element 14.

[0053] In the embodiment of the present application, the photosensitive element 1 for realizing the front camera function is a color image sensor, which can be used to measure the ambient light spectrum of visible light wavelengths. Figure 5 As shown, the photosensitive element 1 includes a plurality of color photosensitive sub-elements arranged in an array on the photosensitive layer 200 , and the color photosensitive sub-elements include a photosensitive sensor 204 and a color resist block 207 arranged on the photosensitive sensor 204 .

[0054] Each of the color photosensitive sub-elements is arranged inside one of the receiving grooves 202, and each of the color photosensitive sub-elements corresponds to one of the color resist blocks 207. For example, a blue photosensitive sub-element and a blue color resist block are located in the same receiving groove 202. The blue color resist block is used to filter the blue light entering it so as to allow the three primary colors of light used for color display to pass through (for example, the green color resist block can only pass green light, the red color resist block can only pass red light, and the blue color resist block can only pass blue light).

[0055] The color photosensitive sub-element also includes a lens 205 disposed on a side of the color resist block 207 away from the base substrate 11. The lens 205 is provided in a one-to-one correspondence with the light sensor 204. The orthographic projection of the center of the lens 205 on the base substrate 11 overlaps with the orthographic projection of the center of the light sensor 204 on the base substrate 11. The lens 205 is configured to convert ambient light incident on the lens 205 into collimated light or focused light. The size of the lens 205 can be the same as that of the color resist block 207.

[0056] The edge of the color resist block 207 contacts the light-shielding layer 211, and the upper surface of the color resist block 207 is flush with the upper surface of the insulating layer 201. This design can better suppress stray light caused by the refraction and reflection effects of the microstructure in the display screen (such as the light-emitting structure and its driving structure), especially the influence of the light-emitting structure in the display screen on the photosensitive element 1, thereby improving imaging accuracy.

[0057] The photosensitive layer 200 includes a transparent protective layer 206 disposed on a side of the insulating layer 201 away from the base substrate 11, and the lens 205 is disposed inside the transparent protective layer 206. The transparent protective layer 206 can be made of silicon nitride, silicon oxide, or a mixture of silicon nitride and silicon oxide.

[0058] In an embodiment of the present application, the display panel 100 further includes a color filter layer 16 disposed on a side of the encapsulation layer 15 away from the substrate 208, the color filter layer 16 including a plurality of color filters 101 and a black matrix 102; the plurality of color filters 101 are arranged in an array; and the black matrix 102 separates the plurality of color filters 101. Typically, color filters may include: a red filter, a green filter, and a blue filter, and color filters 101 of the same color correspond one-to-one to sub-pixels of the same color. By utilizing a plurality of color filters 101 and a black matrix 102, while preventing at least a portion of the reflected light of the external ambient light from being emitted outside the display panel 100, the light transmittance of the display panel 100 is increased, thereby improving the display effect of the display device and reducing the power consumption of the display device.

[0059] In one possible embodiment, the photosensitive layer 200 is disposed above the color filter layer 16, and the corresponding photosensitive element 1 in the photosensitive layer 200 is disposed at a position corresponding to the black matrix 102. The light received by the photosensitive element 1 does not affect other hierarchical structures of the display panel 100, and the display panel 100 has good transmittance. At the same time, the light from the organic light-emitting element 14 is prevented from affecting the photosensitive element 1 when passing through the color filter 101.

[0060] It should be noted that, in other embodiments, the photosensitive layer 200 can also be provided on any layer of the display panel 100 located above the sub-pixel, the photosensitive layer 200 is provided above the encapsulation layer 15, the color filter and the color block 207 on the photosensitive layer 200 are made of the same material, and the black matrix 102 and the light-shielding layer 211 are made of the same material. The color block 207 on the photosensitive layer 200 and the color filter 101 on the color filter layer 16 are formed by the same process, and the light-shielding layer 211 on the photosensitive layer 200 and the black matrix 102 on the color filter layer 16 are formed by the same process. With this arrangement, the thickness of the display panel 100 can be reduced and the preparation process can be simplified. In application, different arrangements can be made according to different devices or application scenarios, and this application does not limit this.

[0061] The plurality of sub-pixel units P arranged in an array on the display panel 100 form a plurality of pixel rows arranged in an array along a first direction X and a plurality of pixel columns arranged in an array along a second direction Y.

[0062] In the embodiment of the present application, the first direction X and the second direction Y may be perpendicular to each other, or nearly perpendicular to each other. The present application does not limit the specific directions of the first direction X and the second direction Y. Of course, in other embodiments, the first direction X and the second direction Y may be interchangeable. The first direction X may be the direction in which pixel columns (photosensitive columns) are arranged, and the second direction Y may be the direction in which pixel rows (photosensitive rows) are arranged.

[0063] It should also be noted that, in the embodiment of the present application, the sub-pixel units P include a red sub-pixel unit P, a green sub-pixel unit P, and a blue sub-pixel unit P arranged in an array. Although each sub-pixel is described as including a red sub-pixel unit, a green sub-pixel unit P, and a blue sub-pixel unit P, the present invention is not limited thereto. The colors of the sub-pixel units P can also be described as a first color, a second color, and a third color, and the first color, the second color, and the third color can also be cyan, magenta, and yellow. In addition, the sub-pixel can include a white sub-pixel unit P.

[0064] In the embodiment of the present application, the arrangement of the sub-pixel units P in each pixel unit is not limited. The arrangement of the sub-pixel units P can be a strip arrangement, an island arrangement, a mosaic arrangement, or a herringbone arrangement. In application, different settings can be made according to different devices or application scenarios. The shape of each sub-pixel can be a polygon, such as a quadrilateral or a hexagon; it can also be a non-polygonal shape, such as a circular or elliptical shape, which is not limited in the embodiment of the present invention.

[0065] The plurality of color photosensitive sub-elements arranged in an array on the photosensitive layer 200 form a plurality of photosensitive rows in an array along a first direction X and a plurality of photosensitive columns in an array along a second direction Y.

[0066] In this embodiment, the color photosensitive sub-elements are arranged in the same array as the sub-pixel units P, and the color photosensitive sub-elements and sub-pixels can have the same shape. Since the orthographic projection of the photosensitive element 1 on the substrate 11 does not overlap with the orthographic projection of the sub-pixel units P on the substrate 11, in order to avoid affecting the pixel arrangement of the existing display panel 100, the photosensitive sub-elements are arranged at the intersection between the sub-pixel units P. In this embodiment, the size and number of the color photosensitive sub-elements vary according to the shape and size of the sub-pixels.

[0067] In order to increase the area of ​​the color photosensitive sub-element and reduce the difficulty of preparation, the present application provides an exemplary arrangement of sub-pixels and color photosensitive sub-elements, in which the sub-pixel units P in each pixel unit are arranged in a herringbone shape, and the color photosensitive sub-element is located at the intersection of the first sub-pixel, the second sub-pixel, and the third sub-pixel, that is, in the blank position between the three sub-pixels, and is adjacent to the first sub-pixel, the second sub-pixel, and the third sub-pixel.

[0068] In this embodiment, the ratio of the sub-pixel density to the color photosensitive sub-element density is 3:1. That is, a color photosensitive sub-element is provided in each pixel unit. This approach increases the area of ​​a single color photosensitive sub-element and reduces manufacturing difficulty. It is understood that this is not limited to this embodiment and will be determined based on the device or application scenario. In this embodiment, color photosensitive sub-elements of the same color are arranged in the same photosensitive row, and color photosensitive sub-elements of different colors are arranged alternately in the same photosensitive column.

[0069] It should be noted that in the embodiment of the present application, the color photosensitive sub-element is arranged on the entire surface of the display area of ​​the display panel 100, which can increase the photosensitivity accuracy and improve the shooting effect, but the embodiment of the present application is not limited to this. In some possible embodiments, the photosensitive element 1 array can be arranged in the entire display area as needed, and reused as a fingerprint recognition unit and other purposes; it can also be arranged in a preset area to achieve a shooting effect, for example, it can be applied only to the camera area or the fingerprint recognition area.

[0070] It should be further clarified that in the embodiment of the present application, the ambient light collected by the photosensitive element 1 is used to realize the shooting function, which is different from the fingerprint imaging in the prior art. The display panel 100 uses the image sensor and the small holes designed in the OLED display panel 100 to realize fingerprint imaging through the small hole imaging principle.

[0071] Fingerprint imaging utilizes an OLED as a light source. Light from the OLED is reflected upon reaching the finger's skin on the touchscreen surface, forming a reflected beam that travels toward a photosensitive element 1 beneath the touchscreen. This reflected light is then received by the photosensitive element 1, which then generates a fingerprint image based on the reflected light, thereby achieving fingerprint recognition. Specifically, the pinhole imaging principle requires the pinhole opening to be as small as possible, typically limited to 5-40μm. Furthermore, to prevent overlap of sub-images formed by different pinholes on the image plane, the pinhole spacing is kept sufficiently large, typically within a range of 1-1.5mm.

[0072] The optical principle diagram of pinhole optical fingerprint imaging is as follows Figure 6 As shown. Lo is the object distance, Li is the image distance, F is the size of the finger area recognized by each imaging pinhole, and S is the imaging size of each imaging pinhole on the photosensor. If the size of the hole remains unchanged, the image distance (the distance from the image to the pinhole) remains unchanged and the object distance increases, then the resolution of the imaging will decrease, otherwise the resolution will increase. Therefore, the fingerprint recognition technology in the prior art cannot achieve the function of the front camera in this application. The principle of the photosensitive layer 200 being used to capture the external image will be described in detail below.

[0073] In this embodiment, the photosensor 204 includes a photosensitive layer PIN and a photosensitive circuit layer 203 located on the side of the photosensitive layer PIN near the base substrate 11. A photosensitive circuit electrically connected to the photosensitive layer is provided on the photosensitive circuit layer 203. The photosensitive layer is configured to perform photoelectric conversion on incident light in the optical path; the photosensitive circuit is configured to transmit the resulting photoelectrically converted electrical signal to peripheral circuitry for processing. The photosensitive circuit layer 203 can be implemented using one or more metal layers.

[0074] Figure 7, a schematic structural diagram of a photosensor 204 is shown, which includes a first electrode 209 made of a metal conductive material, a second electrode 210 made of a transparent conductive material, and a photosensitive layer PIN located between the first electrode 209 and the second electrode 210. In one example, the first electrode 209 and the second electrode 210 are both in contact with the photosensitive layer PIN. It should be noted that the present disclosure does not limit the material of the photosensitive layer PIN, and those skilled in the art can select it as needed. For example, the photosensitive layer PIN can be a PIN junction photodiode or a photosensitive transistor. In addition, the first electrode 209 can be formed by the source and drain metal layer 107 of the thin film transistor.

[0075] like Figure 8 、 9 As shown, the photosensitive circuit layer 203 includes a substrate 208 and a reset thin film transistor T1, a driving thin film transistor T2, and a switch thin film transistor T3 formed on the substrate 208. It should be understood that the substrate 208 here can be a glass substrate 208 or a flexible substrate 208. The thin film transistor TFT can adopt various structures in the prior art, which are not limited in this application, for example, including functional layers such as a buffer layer, a P-Si layer, a GI layer, a gate layer, an ILD layer, and an SD layer.

[0076] Among them, the control end of the driving thin film transistor T2 is connected to the photosensitive layer PIN, the first end of the driving thin film transistor T2 is connected to the data voltage line Vdd, and the second end of the driving thin film transistor T2 is connected to the first end of the switching thin film transistor T3; the first end of the reset thin film transistor T1 is connected to the reset voltage line Vrst, the second end of the reset thin film transistor T1 is connected to the control end of the driving thin film transistor T2 and the photosensitive layer PIN, and the control end of the reset thin film transistor T1 is connected to the reset signal line Reset; the control end of the switching thin film transistor T3 is connected to the gate control line Gate, the first end of the switching thin film transistor T3 is connected to the second end of the driving thin film transistor T2, and the second end of the switching thin film transistor T3 is connected to the output voltage line Vout.

[0077] In this embodiment, the driving thin-film transistor T2 is used to convert the charge change in the photosensitive layer PIN into a current change; when the reset thin-film transistor T1 is turned on, the PT point potential is reset to the reset voltage (Vrst) to reset the optical sensor; when the reset thin-film transistor T1 is turned off, the optical sensor enters the photosensitivity stage, and the PD point potential decreases due to the accumulation of photocharges; the switching thin-film transistor T3 controls the signal output to control whether the photosensitive layer PIN is in the state of collecting light signals and the time for collecting light signals.

[0078] In addition, in the embodiment of the present application, the photosensitive layer PIN and the reset thin film transistor T1, the driving thin film transistor T2 and the switch thin film transistor T3 are basically not overlapped in configuration, so as to reduce the interference of the noise brought by the capacitance change caused by the overlap on the PIN.

[0079] In this embodiment, the color photosensitive sub-elements are arranged in the entire display area of ​​the display panel 100 as an example for description. Figure 9-10 As shown, the photosensitive circuit layer 203 includes multiple data voltage lines Vdd arranged along a first direction X and multiple gate control lines Gate arranged along a second direction Y. The intersection of the data voltage lines Vdd and the gate control lines Gate defines a single photosensitive sensor 204. One data voltage line Vdd is connected to a photosensitive circuit located in the same photosensitive column, and one gate control line Gate is connected to a photosensitive circuit located in the same photosensitive row. Furthermore, the reset voltage line Vrst and the output voltage line Vout are both arranged along the first direction X, and the reset signal line Reset is arranged along the second direction Y.

[0080] In this embodiment, the photosensitive element 1 includes three different colored photosensitive sub-elements: a first color R, a second color G, and a third color B. The same color photosensitive sub-elements are arranged in the same photosensitive row, while the different color photosensitive sub-elements are arranged in RGB order in the same photosensitive column. The color photosensitive sub-elements in the photosensitive column connected to the same output voltage line Vout are all color photosensitive sub-elements. The output voltage line Vout is located on the same side of the same photosensitive column and between two adjacent photosensitive columns.

[0081] When applied, this embodiment can use a row-by-row scanning method to detect the electrical signals of each photosensitive sensor 204, and provide input signals to each row of photosensitive sensors 204 in turn to put the photosensitive sensors 204 into working state, and then obtain the electrical signal output by the output voltage line Vout of each column of photosensitive sensors 204. After the row-by-row scanning is completed, the electrical signal output by the entire surface of the photosensitive sensors 204 is obtained, and finally processed by the image processing chip (IC) to obtain the captured image, and sent to the display panel 100 through the image processing chip (IC) for image display.

[0082] like Figure 11 As shown, the present application also provides a method for preparing an under-screen light sensing module, which is used to prepare any of the above under-screen light sensing modules, and the method includes:

[0083] S100 , forming a display panel 100 , wherein the display panel 100 includes a base substrate 11 and a plurality of sub-pixel units P arranged in an array on the base substrate 11 .

[0084] Specifically, the display panel 100 is formed by sequentially forming one or more of a pixel driving circuit layer 12 , a pixel defining layer 13 , an organic light emitting element 14 , an encapsulation layer 15 , and a color filter layer 16 on a base substrate 11 .

[0085] S200, forming a photosensitive layer 200 on the display panel 100, wherein the photosensitive layer 200 is used to capture external images, and the photosensitive layer 200 includes a plurality of photosensitive elements 1 arranged in an array, and the orthographic projection of the photosensitive element 1 on the base substrate 11 does not overlap with the orthographic projection of the sub-pixel unit P on the base substrate 11.

[0086] Specifically, the photosensitive layer 200 is formed by forming an insulating layer 201 on the display panel 100 and patterning the insulating layer 201 to form a receiving groove 202; forming a light shielding layer 211 on the insulating layer 201 and patterning the layer to cover the sidewalls and bottom of the receiving groove 202; forming a photosensitive circuit layer 203 and a photosensitive layer on the light shielding layer 211; forming a color resist block 207 on the photosensitive layer; forming a lens 205 on the color resist block 207; and forming a transparent protective layer 206 on the lens 205. It is understood that the photosensitive layer 200 can also be formed into an independent film layer using film forming technology and attached to the display panel 100.

[0087] Based on the same inventive concept, the present application provides a display device, including an under-screen light sensing module as described above. The specific structure of the under-screen light sensing module has been described in detail in the above embodiments and will not be repeated here. The display device in the embodiment of the present application can be a TV, or it can be a PC, a smart phone, a tablet computer, an e-book reader, an MP3 (Moving Picture Experts Group Audio Layer III, Moving Picture Experts Group Audio Layer) player, an MP4 (Moving Picture Experts Group Audio Layer IV, Moving Picture Experts Group Audio Layer) player, a portable computer, and other devices with display functions.

[0088] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0089] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0090] Unless otherwise defined, the technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art in the art of the present invention. The terms used herein are only for describing specific implementation purposes and are not intended to limit the present invention. Terms such as "setting" appearing in this article can mean that one component is directly attached to another component, or that one component is attached to another component through an intermediate component. Features described in this article in one embodiment can be applied to another embodiment alone or in combination with other features, unless the feature is not applicable in the other embodiment or otherwise specified.

[0091] The present invention has been described through the above embodiments, but it should be understood that the above embodiments are for illustrative and illustrative purposes only and are not intended to limit the present invention to the described embodiments. Those skilled in the art will appreciate that various variations and modifications may be made based on the teachings of the present invention, and such variations and modifications fall within the scope of protection claimed in the present invention.

Claims

1. An under-screen light sensor module, characterized in that: include: A display panel, comprising a base substrate and a plurality of sub-pixel units arranged in an array on the base substrate; A photosensitive layer is provided on the display panel, the photosensitive layer is used to capture external images, the photosensitive layer includes a plurality of photosensitive elements arranged in an array, and the orthographic projections of the photosensitive elements on the base substrate do not overlap with the orthographic projections of the sub-pixel units on the base substrate; The photosensitive layer includes an insulating layer provided on a side of the sub-pixel unit away from the base substrate, the insulating layer is provided with a receiving groove, the orthographic projection of the receiving groove on the base substrate does not overlap with the orthographic projection of the sub-pixel unit on the base substrate, and the photosensitive element is located inside the receiving groove; The sidewall and bottom surface of the accommodating groove are covered with a light shielding layer, and the light shielding layer is located between the photosensitive element and the insulating layer.

2. The under-screen light sensor module according to claim 1, wherein: The photosensitive element includes a plurality of color photosensitive sub-elements arranged in an array on the photosensitive layer, and the color photosensitive sub-elements include a photosensitive sensor and a color resist block arranged on the photosensitive sensor.

3. The under-screen light sensor module according to claim 2, wherein: The plurality of color photosensitive sub-elements arranged in an array on the photosensitive layer form a plurality of photosensitive rows arrayed along a first direction and a plurality of photosensitive columns arrayed along a second direction; The plurality of sub-pixel units arranged in an array on the display panel form a plurality of pixel rows arranged in an array along a first direction and a plurality of pixel columns arranged in an array along a second direction.

4. The under-screen light sensor module according to claim 2, wherein: Each of the color photosensitive sub-elements is arranged inside a said accommodating groove, and each of the color photosensitive sub-elements corresponds to a said color resist block, the edge of the said color resist block contacts the said light shielding layer, and the upper surface of the said color resist block is flush with the upper surface of the said insulating layer.

5. The under-screen light sensor module according to claim 2, wherein: The color photosensitive element also includes a lens arranged on the side of the color block away from the base substrate. The lens is arranged in a one-to-one correspondence with the photosensitive sensor, and the orthographic projection of the center of the lens on the base substrate overlaps with the orthographic projection of the center of the photosensitive sensor on the base substrate.

6. The under-screen light sensor module according to claim 5, characterized in that: The photosensitive layer includes a transparent protective layer arranged on a side of the insulating layer away from the base substrate, and the lens is arranged inside the transparent protective layer.

7. The under-screen light sensor module according to claim 3, wherein: The photosensor includes a photosensitive layer and a photosensitive circuit layer located on a side of the photosensitive layer close to the base substrate. The photosensitive circuit layer is provided with a photosensitive circuit electrically connected to the photosensitive layer.

8. The under-screen light sensor module according to claim 7, wherein: The photosensitive circuit layer includes multiple data voltage lines arranged along the first direction and multiple gate control lines arranged along the second direction. One data voltage line is connected to the photosensitive circuit located in the same photosensitive column, and one gate control line is connected to the photosensitive circuit located in the same photosensitive row.

9. A method for preparing an under-screen optical sensor module, characterized in that: For preparing the under-screen light sensing module according to any one of claims 1 to 8, the method comprises: forming a display panel, the display panel comprising a base substrate and a plurality of sub-pixel units arranged in an array on the base substrate; A photosensitive layer is formed on the display panel, and the photosensitive layer is used to capture external images. The photosensitive layer includes a plurality of photosensitive elements arranged in an array, and the orthographic projections of the photosensitive elements on the base substrate do not overlap with the orthographic projections of the sub-pixel units on the base substrate.

10. A display device, characterized in that: It includes the under-screen light sensing module as described in any one of claims 1-8.

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