Display substrate and manufacturing method therefor, and display apparatus

Abstract

The present disclosure relates to the technical field of display, and provides a display substrate and a manufacturing method therefor, and a display apparatus. The display substrate comprises: a base substrate; light-emitting units and photoelectric sensing units located on the base substrate, the photoelectric sensing units being configured to generate electrical signals on the basis of light emitted by the light-emitting units and to transmit the electrical signals to a recognition circuit, and the recognition circuit being configured to be connected to a fingerprint recognition chip and to transmit the received electrical signals to the fingerprint recognition chip; and lens units, located on the side of the photoelectric sensing units away from the base substrate, the lens units corresponding to the photoelectric sensing units on a one-to-one basis, wherein each lens unit comprises a convex surface protruding away from the base substrate, an orthographic projection of each lens units on the base substrate overlaps with an orthographic projection of a photoelectric sensing unit on the base substrate, and the refractive index of the lens units is greater than the refractive index of a first film layer. The present disclosure can improve fingerprint recognition accuracy.

Description

Display substrate and its manufacturing method, display device

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510110237.3, filed in China on January 23, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of display technology, and in particular to a display substrate, a method for manufacturing the same, and a display device. Background Technology

[0004] The array substrates of electronic products such as mobile phones and tablets usually have a display area for displaying images, and the display area has a fingerprint recognition function.

[0005] In related technologies, the display area includes multiple light-emitting units (such as sub-pixel units), multiple organic photodiode (OPD) units, and multiple OPD circuits. The OPD units are located between the light-emitting units, and each OPD unit is connected to a corresponding OPD circuit. The OPD circuits are connected to a fingerprint recognition chip. When a finger touches the display area, the light-emitting units emit light. The light is reflected by the finger and received by the OPD units. The OPD units generate electrical signals based on the received light and transmit these signals to the OPD circuits. The OPD circuits then transmit these signals to the fingerprint recognition chip, which performs fingerprint recognition based on the electrical signals sent by each OPD circuit. Summary of the Invention

[0006] This disclosure provides a display substrate and its manufacturing method, as well as a display device, which can improve fingerprint recognition accuracy.

[0007] The embodiments of this disclosure provide the following technical solutions:

[0008] On one hand, a display substrate is provided, comprising:

[0009] Substrate;

[0010] The light-emitting unit and the photoelectric sensing unit are located on the substrate. The photoelectric sensing unit is used to generate an electrical signal based on the light emitted by the light-emitting unit and transmit the electrical signal to the recognition circuit. The recognition circuit is used to connect to the fingerprint recognition chip and transmit the received electrical signal to the fingerprint recognition chip.

[0011] A lens unit is located on the side of the photoelectric sensing unit away from the substrate. Each lens unit corresponds to a photoelectric sensing unit. Each lens unit includes a convex surface that protrudes towards the side away from the substrate. The orthographic projection of the lens unit on the substrate overlaps with the orthographic projection of the photoelectric sensing unit on the substrate. The refractive index of the lens unit is greater than the refractive index of the first film layer, which is located on the side of the lens unit away from the substrate.

[0012] In some embodiments, the first film layer is adjacent to the lens unit.

[0013] In some embodiments, the lens unit further includes a concave surface that convexes toward the side closer to the substrate.

[0014] In some embodiments, the central axis of the lens unit coincides with the central axis of the photoelectric sensing unit; or the central axis of the lens unit is offset from the central axis of the photoelectric sensing unit by a predetermined distance.

[0015] In some embodiments, the orthographic projection of the photoelectric sensing unit on the substrate is located within the orthographic projection of the corresponding lens unit on the substrate.

[0016] In some embodiments, the shortest distance between the boundary of the photoelectric sensing unit and the boundary of the convex surface in a first direction parallel to the substrate is L1, the shortest distance between the boundary of the photoelectric sensing unit and the boundary of the concave surface in the first direction is L2, and the shortest distance between the boundary of the photoelectric sensing unit and the boundary of the lens unit in the first direction is L3, wherein L1≤L2<L3 or L2<L1<L3.

[0017] In some embodiments, L3 is greater than or equal to 1 micrometer.

[0018] In some embodiments, the distance between the photoelectric sensing unit and the substrate is different from the distance between the light-emitting unit and the substrate in a direction perpendicular to the substrate.

[0019] In some embodiments, in a direction perpendicular to the substrate, the distance between the photoelectric sensing unit and the substrate is greater than the distance between the light-emitting unit and the substrate, and the distance difference is greater than 0.1 micrometers.

[0020] In some embodiments, the pixel defining layer includes a first side surface adjacent to the photoelectric sensing unit and a second side surface adjacent to the light-emitting unit, the slope angle of the first side surface is θ1, the slope angle of the second side surface is θ2, and the slope angle of the second pixel defining layer pattern is θ2, wherein θ1 < θ2.

[0021] In some embodiments, θ1 is less than 25° and θ2 is less than 50°.

[0022] In some embodiments, the refractive index of the lens unit is 1.6-3.0.

[0023] In some embodiments, the first film layer includes:

[0024] A first organic film layer is located on the side of the lens unit away from the substrate, the surface height of the first organic film layer is greater than the surface height of the lens unit, and the refractive index of the first organic film layer is less than the refractive index of the lens unit.

[0025] In some embodiments, the display substrate includes a plurality of sub-pixels arranged in an array, the plurality of sub-pixels including a first sub-pixel column and a second sub-pixel column arranged alternately along a third direction, the first sub-pixel column including red sub-pixels and blue sub-pixels arranged alternately along a fourth direction, the second sub-pixel column including a plurality of green sub-pixels arranged at intervals along the fourth direction, the photoelectric sensing unit being located between adjacent green sub-pixels, the third direction being perpendicular to the fourth direction.

[0026] In some embodiments, the orthographic projection of the lens unit onto the substrate is circular or rectangular.

[0027] Embodiments of this disclosure also provide a display device, including the display substrate described above.

[0028] Embodiments of this disclosure also provide a method for manufacturing a display substrate, comprising:

[0029] Provide substrates;

[0030] A light-emitting unit and a photoelectric sensing unit are formed on the substrate. The photoelectric sensing unit is used to generate an electrical signal based on the light emitted by the light-emitting unit and transmit the electrical signal to the recognition circuit. The recognition circuit is used to connect to the fingerprint recognition chip and transmit the received electrical signal to the fingerprint recognition chip.

[0031] A lens unit is formed on the side of the photoelectric sensing unit away from the substrate. The lens unit corresponds to the photoelectric sensing unit one by one. The lens unit includes a convex surface that protrudes towards the side away from the substrate. The orthographic projection of the lens unit on the substrate overlaps with the orthographic projection of the photoelectric sensing unit on the substrate. The refractive index of the lens unit is greater than the refractive index of the first film layer, which is located on the side of the lens unit away from the substrate.

[0032] In some embodiments, forming the light-emitting unit and the photoelectric sensing unit includes:

[0033] A planarization layer is formed on the substrate.

[0034] The planarization layer is patterned to form a first planarization layer region and a second planarization layer region. In a direction perpendicular to the substrate, the distance between the first planarization layer region and the substrate is different from the distance between the second planarization layer region and the substrate.

[0035] The photoelectric sensing unit is formed in the first planarization layer region, and the light-emitting unit is formed in the second planarization layer region.

[0036] In some embodiments, the method further includes:

[0037] A pixel defining layer is formed that defines the photoelectric sensing unit and the light-emitting unit. The pixel defining layer includes a first side surface adjacent to the photoelectric sensing unit and a second side surface adjacent to the light-emitting unit. The slope angle of the first side surface is θ1, and the slope angle of the second side surface is θ2, where θ1 < θ2.

[0038] In some embodiments, forming the lens unit includes:

[0039] A second organic film layer is formed on the side of the photoelectric sensing unit away from the substrate, and the refractive index of the second organic film layer is less than the refractive index of the lens unit;

[0040] The second organic film layer is patterned to form a groove, the groove including a concave surface that protrudes toward the side close to the substrate, the radius of curvature of the concave surface being smaller than the radius of curvature of the convex surface;

[0041] The lens unit is formed within the groove.

[0042] The embodiments disclosed herein have the following beneficial effects:

[0043] In the above scheme, a lens unit is set on the side of the photoelectric sensing unit away from the substrate. The refractive index of the lens unit is greater than that of the first film layer. In this way, when the light emitted from the display substrate is reflected by an external object such as a finger, it passes through the first film layer and shines on the lens unit. It can be refracted and focused towards the central axis of the lens unit, and then incident on the photoelectric sensing unit. This allows as much of the fingerprint reflected light as possible to be incident on the surface of the photoelectric sensing unit, increasing the amount of light received by the photoelectric sensing unit, generating more photocurrent, and thus improving the fingerprint recognition accuracy. Attached Figure Description

[0044] Figures 1 and 2 are schematic diagrams of the structure of a display substrate according to an embodiment of the present disclosure;

[0045] Figure 3 is a schematic diagram showing that the central axis of the lens unit coincides with the central axis of the photoelectric sensing unit in an embodiment of this disclosure;

[0046] Figure 4 is a schematic diagram of the lens unit disposed between adjacent green sub-pixels according to an embodiment of the present disclosure;

[0047] Figure 5 is a schematic diagram of light propagation in the display substrate according to an embodiment of this disclosure;

[0048] Figure 6 is a schematic diagram of light that is not parallel to the principal optical axis entering the lens and being focused to the secondary focal point;

[0049] Figures 7-10 are schematic diagrams showing that the central axis of the lens unit and the central axis of the photoelectric sensing unit are a certain distance apart in the embodiments of this disclosure;

[0050] Figures 11-17 are schematic diagrams of the fabrication of a display substrate according to an embodiment of this disclosure.

[0051] Reference numerals: 01 Substrate; 02 Barrier layer; 03 Light-shielding metal layer; 04 First insulating layer; 05 Active layer; 06 Second insulating layer; 07 / 08 Gate metal layer; 09 Third insulating layer; 10 Fourth insulating layer; 11 Source / drain metal layer; 12 Planarization layer; 13 Pixel boundary layer; 131 First side surface; 132 Second side surface; 14 Organic encapsulation layer; 15 Second inorganic encapsulation layer; 16 First touch insulating layer; 17 Second touch insulating layer; 18 Second organic film layer; 181 Groove; 19 First organic film layer; 20 Light-emitting unit; 21 Anode of light-emitting unit; 22 Organic functional layer of light-emitting unit; 23 Cathode of light-emitting unit; 24 First inorganic encapsulation layer; 30 Photoelectric sensing unit; 31 Anode of photoelectric sensing unit; 32 Organic functional layer of photoelectric sensing unit; 33 Cathode of photoelectric sensing unit; 40 Encapsulation structure; 41 Touch functional layer; 42 Lens unit; 421 Convex surface; 422 Concave surface; 43 Object to be identified. Detailed Implementation

[0052] To make the technical problems, technical solutions and advantages to be solved by the embodiments of this disclosure clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0053] In related technologies, during fingerprint recognition, the light emitted from the display substrate is reflected by the fingerprint, and the reflected light is incident on areas other than the OPD (Optical Display Device), failing to be fully received by the OPD. This results in a low photocurrent generated by the OPD, a weak received signal, and ineffective fingerprint recognition. Embodiments of this disclosure provide a display substrate, a method for manufacturing the same, and a display device, which can improve fingerprint recognition accuracy.

[0054] Embodiments of this disclosure provide a display substrate, comprising:

[0055] Substrate;

[0056] The light-emitting unit and the photoelectric sensing unit are located on the substrate. The photoelectric sensing unit is used to generate an electrical signal based on the light emitted by the light-emitting unit and transmit the electrical signal to the recognition circuit. The recognition circuit is used to connect to the fingerprint recognition chip and transmit the received electrical signal to the fingerprint recognition chip.

[0057] A lens unit is located on the side of the photoelectric sensing unit away from the substrate. Each lens unit corresponds to a photoelectric sensing unit. Each lens unit includes a convex surface that protrudes towards the side away from the substrate. The orthographic projection of the lens unit on the substrate overlaps with the orthographic projection of the photoelectric sensing unit on the substrate. The refractive index of the lens unit is greater than the refractive index of the first film layer, which is located on the side of the lens unit away from the substrate.

[0058] In some embodiments, the first film layer is adjacent to the lens unit.

[0059] In this embodiment, a lens unit is disposed on the side of the photoelectric sensing unit away from the substrate. The refractive index of the lens unit is greater than that of the first film layer. In this way, when the light emitted from the display substrate is reflected by an external object such as a finger, it passes through the first film layer and illuminates the lens unit, where it is refracted and converged towards the central axis of the lens unit before being incident on the photoelectric sensing unit. This allows as much of the fingerprint-reflected light as possible to be incident on the surface of the photoelectric sensing unit, increasing the amount of light received by the photoelectric sensing unit and causing it to generate more photocurrent, thereby improving the fingerprint recognition accuracy.

[0060] Figures 1 and 2 are schematic diagrams of the structure of a display substrate according to an embodiment of the present disclosure. As shown in Figures 1 and 2, the display substrate includes a display backplate and a light-emitting unit 20 and a photoelectric sensing unit 30 disposed on the display backplate. The display backplate includes a substrate 01, a barrier layer 02, a light-shielding metal layer 03, a first insulating layer 04, an active layer 05, a second insulating layer 06, gate metal layers 07 / 08, a third insulating layer 09, a fourth insulating layer 10, a source / drain metal layer 11, and a planarization layer 12. The substrate 01 can be a glass substrate or a quartz substrate; the barrier layer 02 can be made of silicon oxide or silicon nitride, which can prevent impurities and ions in the substrate 01 from entering the display film layer; the orthographic projection of the active layer 05 on the substrate 01 is located within the orthographic projection of the light-shielding metal layer 03 on the substrate 01, and the light-shielding metal layer 03 can prevent light from shining on the active layer 05 and affecting the performance of the thin film transistor; the gate metal layers 07 / 08 can be metals such as Cu, Al, Ag, Mo, Cr, Nd, Ni, Mn, Ti, Ta, W, and alloys of these metals. The gate metal layers can be single-layer or multi-layer structures, such as Cu\Mo, Ti\Cu\Ti, Mo\Al\Mo, etc.; the source / drain metal layers 11 can be metals such as Cu, Al, Ag, Mo, Cr, Nd, Ni, Mn, Ti, Ta, W, and alloys of these metals. The source / drain metal layers can be single-layer or multi-layer structures, such as Cu\Mo, Ti\Cu\Ti, Mo\Al\Mo, etc.

[0061] The light-emitting unit 20 includes an anode 21, an organic functional layer 22, and a cathode 23; the photoelectric sensing unit 30 includes an anode 31, an organic functional layer 32, and a cathode 33. To simplify the structure and manufacturing process of the display substrate, the anode 31 of the photoelectric sensing unit 30 can be disposed in the same layer and with the same material as the anode 21 of the light-emitting unit 20, the organic functional layer 32 of the photoelectric sensing unit 30 can be disposed in the same layer and with the same material as the organic functional layer 22 of the light-emitting unit 20, and the cathode 33 of the photoelectric sensing unit 30 can be disposed in the same layer and with the same material as the cathode 23 of the light-emitting unit 20.

[0062] As shown in Figures 1 and 2, an encapsulation layer is also provided on the side of the light-emitting unit 20 and the photoelectric sensing unit 30 away from the substrate 01. The encapsulation layer includes a first inorganic encapsulation layer 24, an organic encapsulation layer 14, and a second inorganic encapsulation layer 15. A touch structure is also provided on the side of the encapsulation layer away from the substrate 01. The touch structure includes a touch function layer 41, a first touch insulating layer 16, and a second touch insulating layer 17. An encapsulation structure 40 is also provided on the side of the touch structure away from the substrate 01. The encapsulation structure 40 can be composed of multiple composite film materials, including a polarizer, an optical adhesive layer, and a glass cover plate.

[0063] In this embodiment, as shown in Figures 1 and 2, a second organic film layer 18, a lens unit 42, and a first organic film layer 19 are disposed on the side of the photoelectric sensing unit 30 away from the substrate 01. The central axis of the photoelectric sensing unit 30 coincides with the central axis (i.e., the principal optical axis) of the lens unit 42. The refractive index of the lens unit 42 is greater than that of the second organic film layer 18 and the first organic film layer 19. The refractive indices of the second organic film layer 18 and the first organic film layer 19 can be less than 1.6, and the refractive index of the lens unit 42 can be between 1.6 and 3.0. The surface height of the lens unit 42 on the side away from the substrate 01 is not greater than the surface height of the first organic film layer 19 on the side away from the substrate 01.

[0064] As shown in Figure 1, the light emitted by the light-emitting unit 20 illuminates the object 43 to be identified (such as a fingerprint), passes through the first organic film layer 19, and then illuminates the lens unit 42. Due to the fact that the refractive index of the first organic film layer 19 is less than that of the lens unit 42, and the converging effect of the convex surface of the lens unit 42, the light illuminating the surface of the lens unit 42 can be refracted and converged towards the central axis of the lens unit 42, and then incident on the photoelectric sensing unit 30. This allows as much of the fingerprint reflected light as possible to be incident on the surface of the photoelectric sensing unit 30, increasing the amount of light received by the photoelectric sensing unit 30, causing the photoelectric sensing unit 30 to generate more photocurrent, thereby improving the fingerprint recognition accuracy.

[0065] In some embodiments, the orthographic projection of the lens unit 42 on the substrate 01 can be a circle or a rectangle. Of course, the orthographic projection of the lens unit 42 on the substrate 01 can also be other regular shapes, such as triangles or polygons (with more than 4 sides); or the orthographic projection of the lens unit 42 on the substrate 01 can also be an irregular shape.

[0066] As shown in Figure 2, the lens unit 42 includes a convex surface 421 protruding towards the side away from the substrate, and a concave surface 422 protruding towards the side closer to the substrate. The radius of curvature of the convex surface 421 is R2, and the radius of curvature of the concave surface 422 is R1, where R1 is less than R2, greater than R2, or equal to R2. The photoelectric sensing unit 30 receives light reflected from the adjacent light-emitting unit 20 by the object to be identified (e.g., a fingerprint). The reflected light is incident on the area where the photoelectric sensing unit 30 is located at a certain angle. The design of the convex surface 421 and the concave surface 422 allows the light to be better focused, enabling as much of the fingerprint reflected light as possible to be incident on the surface of the photoelectric sensing unit 30, increasing the amount of light received by the photoelectric sensing unit 30, and causing the photoelectric sensing unit 30 to generate more photocurrent, thereby improving the fingerprint recognition accuracy.

[0067] As shown in Figure 2, when R1 is less than R2, the edge of the lens unit 42 is stepped, the height of the convex surface 421 is h1, the height of the etched step on the edge of the lens unit 42 is h2, the height of the concave surface 422 is h3, the height of the concave surface 422 is less than the thickness of the second organic film layer 18, and the thickness of the first organic film layer 19 is greater than the sum of h1 and h2.

[0068] In this embodiment, the boundary of the photoelectric sensing unit 30 can be recessed or expanded relative to any boundary of the lens unit 42 (the boundary of the convex surface 421, the boundary of the concave surface 422, or the outer boundary of the lens unit 42). To ensure that the lens unit 42 converges as much light as possible, the orthographic projection of the lens unit 42 on the substrate 01 covers the orthographic projection of the photoelectric sensing unit 30 on the substrate 01, that is, the orthographic projection of the photoelectric sensing unit 30 on the substrate 01 is located within the orthographic projection of the corresponding lens unit 42 on the substrate 01.

[0069] As shown in Figure 3, both the photoelectric sensing unit 30 and the lens unit 42 are symmetrical with respect to symmetry axes 1 and 2. The shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the convex surface 421 in a first direction parallel to the substrate 01 is L1. The shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the concave surface 422 in the first direction is L2. The shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the lens unit 42 in the first direction is L3, where L1 ≤ L2 < L3 or L2 < L1 < L3. To ensure that the lens unit 42 converges as much light as possible, L3 can be greater than or equal to 1 micrometer.

[0070] In the direction perpendicular to the substrate 01, when the photoelectric sensing unit 30 and the light-emitting unit 20 are located on the same horizontal plane, a significant amount of crosstalk light enters the photoelectric sensing unit 30. This crosstalk light can be light emitted by the light-emitting unit 20 reflected by the touch metal, or light entering the photoelectric sensing unit 30 along the pixel defining layer 13. This crosstalk light is not reflected by the object to be identified 43, which leads to increased signal noise in the photoelectric sensing unit 30 and reduced recognition performance. Therefore, in this embodiment, in the direction perpendicular to the substrate 01, the photoelectric sensing unit 30 can be higher or lower than the light-emitting unit 20, that is, the distance between the photoelectric sensing unit 30 and the substrate 01 is different from the distance between the light-emitting unit 20 and the substrate 01. The photoelectric sensing unit 30 may not be located on the same horizontal plane as the light-emitting unit 20, thus reducing the crosstalk light entering the photoelectric sensing unit 30.

[0071] In some embodiments, as shown in FIG2, the distance between the photoelectric sensing unit 30 and the substrate 01 in the direction perpendicular to the substrate 01 is greater than the distance between the light-emitting unit 20 and the substrate 01, and the distance difference H1 is greater than 0.1 micrometers. This can effectively reduce crosstalk light entering the photoelectric sensing unit 30.

[0072] In this embodiment, as shown in FIG2, the pixel defining layer 13 includes a first side surface 131 adjacent to the photoelectric sensing unit 30 and a second side surface 132 adjacent to the light-emitting unit 20. When the photoelectric sensing unit 30 is not located on the same horizontal plane as the light-emitting unit 20, in order to ensure the leveling of the inkjet-printed organic material layer during the packaging process, the first side surface 131 and the second side surface 132 have different slope angles. The slope angle of the first side surface 131 is θ1, and the slope angle of the second side surface 132 is θ2, where θ1 < θ2.

[0073] In some embodiments, θ1 can be less than 25° and θ2 can be less than 50° to ensure the leveling of the inkjet-printed organic material layer during the encapsulation process. Of course, if the process allows, the smaller the values ​​of θ1 and θ2, the better the leveling of the inkjet-printed organic material layer.

[0074] In some embodiments, the display substrate includes a plurality of sub-pixels arranged in an array, as shown in FIG4. The plurality of sub-pixels includes a first sub-pixel column M1 and a second sub-pixel column M2 arranged alternately along a third direction. The first sub-pixel column M1 includes red sub-pixels P1 and blue sub-pixels P3 arranged alternately along a fourth direction. The second sub-pixel column M2 includes a plurality of green sub-pixels P2 arranged at intervals along the fourth direction. The setting position of the photoelectric sensing unit 30 can be determined according to the spectrum identified by the photoelectric sensing unit 30. In some embodiments, the photoelectric sensing unit 30 can be located between adjacent green sub-pixels P2. The third direction is perpendicular to the fourth direction. FIG1-FIG2 are cross-sectional schematic diagrams in the AA' direction shown in FIG4.

[0075] As shown in Figure 5, the light emitted from the light-emitting unit 20 is reflected by the object 43 to be identified at a certain angle. Some of the large-angle reflected light (not parallel to the principal optical axis of the lens unit 42) is converged outside the photoelectric sensing unit 30 after entering the lens unit 42, causing the photoelectric sensing unit 30 to not receive enough light signal, which poses a risk of reduced recognition accuracy. This is because, as shown in Figure 6, when a light that is not parallel to the principal optical axis enters the lens structure, it will be focused to a secondary focal point and not to the principal focal point.

[0076] To ensure sufficient light signal reception by the photoelectric sensing unit 30 and guarantee recognition accuracy, in this embodiment, the principal optical axis of the lens unit 42 (i.e., the central axis of the lens unit 42) is offset relative to the central axis of the photoelectric sensing unit 30. This allows large-angle reflected light to converge into the photoelectric sensing unit 30, increasing the amount of light signal received by the photoelectric sensing unit 30 and thus improving recognition accuracy. As shown in Figure 7, the photoelectric sensing unit 30 is symmetrical with respect to symmetry axes 1 and 2; the lens unit 42 is symmetrical with respect to symmetry axes 1' and 2; the distance between symmetry axes 1' and 1 in the first direction is d1. As shown in Figure 8, the distance between the central axis of the photoelectric sensing unit 30 and the central axis of the lens unit 42 is d1, where d1 > 0 micrometers. As shown in Figure 9, by offsetting the principal optical axis of the lens unit 42 relative to the central axis of the photoelectric sensing unit 30, large-angle reflected light is prevented from converging outside the photoelectric sensing unit 30, increasing the amount of light signal received by the photoelectric sensing unit 30 and thus improving recognition accuracy. Of course, the value of d1 cannot be too large. It needs to be less than 1 / 2 of the width of the photoelectric sensing unit 30 in the first direction. If the value of d1 is too large, the light focusing degree of the lens unit 42 will decrease, and it will not be able to achieve the effect of signal enhancement.

[0077] In some embodiments, the principal optical axis of the lens unit 42 (i.e., the central axis of the lens unit 42) can also be offset in multiple directions relative to the central axis of the photoelectric sensing unit 30. As shown in Figure 10, the photoelectric sensing unit 30 is symmetrical with respect to symmetry axis 1 and symmetry axis 2; the lens unit 42 is symmetrical with respect to symmetry axis 1' and symmetry axis 2'; the distance between symmetry axis 1' and symmetry axis 1 in the first direction is d1, and the distance between symmetry axis 2' and symmetry axis 2 in the second direction is d2, where d1 and d2 are greater than 0 micrometers. Of course, the values ​​of d1 and d2 cannot be too large, and both need to be less than 1 / 2 of the width of the photoelectric sensing unit 30 in the first direction. If the values ​​of d1 and d2 are too large, the light-gathering degree of the lens unit 42 will decrease, and it will not be able to achieve the signal enhancement effect.

[0078] Embodiments of this disclosure also provide a display device, including the display substrate described above.

[0079] The display device includes, but is not limited to, components such as: a radio frequency unit, a network module, an audio output unit, an input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, and a power supply. Those skilled in the art will understand that the structure of the display device described above does not constitute a limitation on the display device; the display device may include more or fewer of the aforementioned components, or combine certain components, or arrange different components. In the embodiments of this disclosure, the display device includes, but is not limited to, a monitor, a mobile phone, a tablet computer, a television set, a wearable electronic device, a navigation display device, etc.

[0080] The display device can be any product or component with display function, such as a television, monitor, digital photo frame, mobile phone, or tablet computer. The display device also includes a flexible circuit board, a printed circuit board, and a backplate.

[0081] Embodiments of this disclosure also provide a method for manufacturing a display substrate, comprising:

[0082] Provide substrates;

[0083] A light-emitting unit and a photoelectric sensing unit are formed on the substrate. The photoelectric sensing unit is used to generate an electrical signal based on the light emitted by the light-emitting unit and transmit the electrical signal to the recognition circuit. The recognition circuit is used to connect to the fingerprint recognition chip and transmit the received electrical signal to the fingerprint recognition chip.

[0084] A lens unit is formed on the side of the photoelectric sensing unit away from the substrate. The lens unit corresponds to the photoelectric sensing unit one by one. The lens unit includes a convex surface that protrudes towards the side away from the substrate. The orthographic projection of the lens unit on the substrate overlaps with the orthographic projection of the photoelectric sensing unit on the substrate. The refractive index of the lens unit is greater than the refractive index of the first film layer, which is located on the side of the lens unit away from the substrate.

[0085] In this embodiment, a lens unit is formed on the side of the photoelectric sensing unit away from the substrate. The refractive index of the lens unit is greater than that of the first film layer. In this way, when the light emitted from the display substrate is reflected by an external object such as a finger, it passes through the first film layer and shines on the lens unit. It can be refracted and focused towards the central axis of the lens unit, and then incident on the photoelectric sensing unit. This allows as much of the fingerprint reflected light as possible to be incident on the surface of the photoelectric sensing unit, increasing the amount of light received by the photoelectric sensing unit, generating more photocurrent, and thus improving the fingerprint recognition accuracy.

[0086] In some embodiments, the manufacturing method of this embodiment includes the following steps:

[0087] Step 1: As shown in Figure 11, a display backplate is formed, and the anode 31 of the light-emitting unit 20 and the anode 21 of the photoelectric sensing unit 30 located on the display backplate are formed, and a pixel defining layer 13 is formed.

[0088] The display backplane includes a substrate 01, a barrier layer 02, a light-shielding metal layer 03, a first insulating layer 04, an active layer 05, a second insulating layer 06, gate metal layers 07 / 08, a third insulating layer 09, a fourth insulating layer 10, a source / drain metal layer 11, and a planarization layer 12. The substrate 01 can be a glass substrate or a quartz substrate; the barrier layer 02 can be made of silicon oxide or silicon nitride, which can prevent impurities and ions in the substrate 01 from entering the display film layer; the orthographic projection of the active layer 05 on the substrate 01 is located within the orthographic projection of the light-shielding metal layer 03 on the substrate 01, and the light-shielding metal layer 03 can prevent light from shining on the active layer 05 and affecting the performance of the thin film transistor; the gate metal layers 07 / 08 can be metals such as Cu, Al, Ag, Mo, Cr, Nd, Ni, Mn, Ti, Ta, W, and alloys of these metals. The gate metal layers can be single-layer or multi-layer structures, such as Cu\Mo, Ti\Cu\Ti, Mo\Al\Mo, etc.; the source / drain metal layers 11 can be metals such as Cu, Al, Ag, Mo, Cr, Nd, Ni, Mn, Ti, Ta, W, and alloys of these metals. The source / drain metal layers can be single-layer or multi-layer structures, such as Cu\Mo, Ti\Cu\Ti, Mo\Al\Mo, etc.

[0089] The light-emitting unit 20 includes an anode 21, an organic functional layer 22, and a cathode 23; the photoelectric sensing unit 30 includes an anode 31, an organic functional layer 32, and a cathode 33; in order to simplify the structure and manufacturing process of the display substrate, the anode 31 of the photoelectric sensing unit 30 can be set in the same layer and with the same material as the anode 21 of the light-emitting unit 20.

[0090] During the patterning of the planarization layer 12, a layer with a thickness of approximately 4000 nm can be coated on the display substrate. An organic resin, which can be benzocyclobutene (BCB) or other organic photosensitive materials, is used to pattern the planarization layer 12, forming a first planarization layer region and a second planarization layer region. In a direction perpendicular to the substrate 01, the distance between the first planarization layer region and the substrate 01 is different from the distance between the second planarization layer region and the substrate 01. Subsequently, the anode 31 of the photoelectric sensing unit and other films can be formed in the first planarization layer region, and the anode 21 of the light-emitting unit and other films can be formed in the second planarization layer region. This ensures that the photoelectric sensing unit 30 and the light-emitting unit 20 are not located on the same horizontal plane, reducing crosstalk light entering the photoelectric sensing unit 30.

[0091] Furthermore, when forming the pattern of the pixel defining layer 13, a grayscale mask or a halftone mask can be used to pattern the pixel defining layer 13, so that the first side surface 131 and the second side surface 132 of the pixel defining layer 13 have different slope angles. The slope angle of the first side surface 131 is θ1, and the slope angle of the second side surface 132 is θ2, where θ1 < θ2. The first side surface 131 is adjacent to the photoelectric sensing unit 30, and the second side surface 132 is adjacent to the light-emitting unit 20. In some embodiments, θ1 can be less than 25°, and θ2 can be less than 50°, which ensures the leveling of the inkjet-printed organic material layer during the encapsulation process. Of course, if the process allows, the smaller the values ​​of θ1 and θ2, the better the leveling of the inkjet-printed organic material layer.

[0092] Step 2: As shown in Figure 12, the organic functional layer 32 and cathode 33 of the photoelectric sensing unit 30 and the organic functional layer 22 and cathode 23 of the light-emitting unit 20 are formed, and the first inorganic encapsulation layer 24 and organic encapsulation layer 14 are formed.

[0093] To simplify the structure and manufacturing process of the display substrate, the organic functional layer 32 of the photoelectric sensing unit 30 can be disposed in the same layer and with the same material as the organic functional layer 22 of the light-emitting unit 20; the cathode 33 of the photoelectric sensing unit 30 can be disposed in the same layer and with the same material as the cathode 23 of the light-emitting unit 20.

[0094] Step 3: As shown in Figure 13, a second inorganic encapsulation layer 15 is formed; and a touch structure is formed on the side of the encapsulation layer away from the substrate 01. The touch structure includes a touch functional layer 41, a first touch insulating layer 16, and a second touch insulating layer 17.

[0095] Step 4: As shown in Figure 14, a second organic film layer 18 is formed. The refractive index of the second organic film layer 18 is less than 1.6. The second organic film layer 18 can be patterned using a gray-toned mask or a halftone mask to form a groove 181. The groove 181 includes a concave surface that protrudes toward the side close to the substrate 01. The radius of curvature of the concave surface is smaller than the radius of curvature of the convex surface of the lens unit 42.

[0096] Step 5: As shown in Figure 15, a high refractive index material layer (the refractive index can be 1.6-3.0) is formed on the substrate. Then, a gray-tone mask or a halftone mask can be used to pattern the high refractive index material layer to form a lens unit 42 in the groove.

[0097] In this embodiment, as shown in Figures 1-2, the central axis of the photoelectric sensing unit 30 can coincide with the central axis (i.e., the main optical axis) of the lens unit 42.

[0098] The boundary of the photoelectric sensing unit 30 can be recessed or expanded relative to any boundary of the lens unit 42 (the boundary of the convex surface 421, the boundary of the concave surface 422, or the outer boundary of the lens unit 42). In order to ensure that the lens unit 42 converges as much light as possible, the orthographic projection of the lens unit 42 on the substrate 01 covers the orthographic projection of the photoelectric sensing unit 30 on the substrate 01, that is, the orthographic projection of the photoelectric sensing unit 30 on the substrate 01 is located within the orthographic projection of the corresponding lens unit 42 on the substrate 01.

[0099] As shown in Figure 3, both the photoelectric sensing unit 30 and the lens unit 42 are symmetrical with respect to symmetry axes 1 and 2. The shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the convex surface 421 in a first direction parallel to the substrate 01 is L1. The shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the concave surface 422 in the first direction is L2. The shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the lens unit 42 in the first direction is L3, where L1 ≤ L2 < L3 or L2 < L1 < L3. To ensure that the lens unit 42 converges as much light as possible, L3 can be greater than or equal to 1 micrometer.

[0100] As shown in Figure 5, the light emitted from the light-emitting unit 20 is reflected by the object 43 to be identified at a certain angle. Some of the large-angle reflected light (not parallel to the principal optical axis of the lens unit 42) is converged outside the photoelectric sensing unit 30 after entering the lens unit 42, causing the photoelectric sensing unit 30 to not receive enough light signal, which poses a risk of reduced recognition accuracy. This is because, as shown in Figure 6, when a light that is not parallel to the principal optical axis enters the lens structure, it will be focused to a secondary focal point and not to the principal focal point.

[0101] To ensure sufficient light signal reception by the photoelectric sensing unit 30 and guarantee recognition accuracy, in this embodiment, the principal optical axis of the lens unit 42 (i.e., the central axis of the lens unit 42) is offset relative to the central axis of the photoelectric sensing unit 30. This allows large-angle reflected light to converge into the photoelectric sensing unit 30, increasing the amount of light signal received by the photoelectric sensing unit 30 and thus improving recognition accuracy. As shown in Figure 7, the photoelectric sensing unit 30 is symmetrical with respect to symmetry axes 1 and 2; the lens unit 42 is symmetrical with respect to symmetry axes 1' and 2; the distance between symmetry axes 1' and 1 in the first direction is d1. As shown in Figure 8, the distance between the central axis of the photoelectric sensing unit 30 and the central axis of the lens unit 42 is d1, where d1 > 0 micrometers. As shown in Figure 9, by offsetting the principal optical axis of the lens unit 42 relative to the central axis of the photoelectric sensing unit 30, large-angle reflected light is prevented from converging outside the photoelectric sensing unit 30, increasing the amount of light signal received by the photoelectric sensing unit 30 and thus improving recognition accuracy. Of course, the value of d1 cannot be too large. It needs to be less than 1 / 2 of the width of the photoelectric sensing unit 30 in the first direction. If the value of d1 is too large, the light focusing degree of the lens unit 42 will decrease, and it will not be able to achieve the effect of signal enhancement.

[0102] In some embodiments, the principal optical axis of the lens unit 42 (i.e., the central axis of the lens unit 42) can also be offset in multiple directions relative to the central axis of the photoelectric sensing unit 30. As shown in Figure 10, the photoelectric sensing unit 30 is symmetrical with respect to symmetry axis 1 and symmetry axis 2; the lens unit 42 is symmetrical with respect to symmetry axis 1' and symmetry axis 2'; the distance between symmetry axis 1' and symmetry axis 1 in the first direction is d1, and the distance between symmetry axis 2' and symmetry axis 2 in the second direction is d2, where d1 and d2 are greater than 0 micrometers. Of course, the values ​​of d1 and d2 cannot be too large, and both need to be less than 1 / 2 of the width of the photoelectric sensing unit 30 in the first direction. If the values ​​of d1 and d2 are too large, the light-gathering degree of the lens unit 42 will decrease, and it will not be able to achieve the signal enhancement effect.

[0103] Step 6: As shown in Figure 16, after forming the lens unit 42, in order to ensure that the subsequent related module materials are flat and to ensure a better light converging effect, a first organic film layer 19 can be formed on the lens unit 42. The surface height of the first organic film layer 19 is greater than the surface height of the lens unit 42, and the refractive index of the first organic film layer 19 is less than the refractive index of the lens unit 42, for example, the refractive index can be less than 1.6.

[0104] Step 7, as shown in Figure 17, forms the encapsulation structure 40. The encapsulation structure 40 can be composed of multiple composite film materials, including a polarizer, an optical adhesive layer, and a glass cover plate, etc.

[0105] The technical solution of this embodiment allows as much reflected light from the fingerprint as possible to be incident on the surface of the photoelectric sensing unit, increasing the amount of light received by the photoelectric sensing unit, generating more photocurrent, and thus improving the fingerprint recognition accuracy.

[0106] In the various method embodiments of this disclosure, the sequence numbers of each step are not intended to limit the order of the steps. For those skilled in the art, any changes in the order of the steps are within the scope of protection of this disclosure without any creative effort.

[0107] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, since the embodiments are basically similar to the product embodiments, the descriptions are relatively simple, and the relevant parts can be referred to the descriptions of the product embodiments.

[0108] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0109] It is understandable that when a component such as a layer, film, region, or substrate is referred to as being "above" or "below" another component, the component may be "directly" located "above" or "below" the other component, or there may be intermediate components present.

[0110] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0111] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A display substrate, characterized in that, include: Substrate; The light-emitting unit and the photoelectric sensing unit are located on the substrate. The photoelectric sensing unit is used to generate an electrical signal based on the light emitted by the light-emitting unit and transmit the electrical signal to the recognition circuit. The recognition circuit is used to connect to the fingerprint recognition chip and transmit the received electrical signal to the fingerprint recognition chip. A lens unit is located on the side of the photoelectric sensing unit away from the substrate. Each lens unit corresponds to a photoelectric sensing unit. Each lens unit includes a convex surface that protrudes towards the side away from the substrate. The orthographic projection of the lens unit on the substrate overlaps with the orthographic projection of the photoelectric sensing unit on the substrate. The refractive index of the lens unit is greater than the refractive index of the first film layer, which is located on the side of the lens unit away from the substrate.

2. The display substrate according to claim 1, characterized in that, The first film layer is adjacent to the lens unit.

3. The display substrate according to claim 1, characterized in that, The lens unit also includes a concave surface that protrudes toward the side closer to the substrate.

4. The display substrate according to claim 1, characterized in that, The central axis of the lens unit coincides with the central axis of the photoelectric sensing unit; or the central axis of the lens unit is offset from the central axis of the photoelectric sensing unit by a predetermined distance.

5. The display substrate according to claim 1, characterized in that, The orthographic projection of the photoelectric sensing unit on the substrate is located within the orthographic projection of the corresponding lens unit on the substrate.

6. The display substrate according to claim 3, characterized in that, The shortest distance between the boundary of the photoelectric sensing unit and the boundary of the convex surface in a first direction parallel to the substrate is L1, the shortest distance between the boundary of the photoelectric sensing unit and the boundary of the concave surface in the first direction is L2, and the shortest distance between the boundary of the photoelectric sensing unit and the boundary of the lens unit in the first direction is L3, wherein L1≤L2<L3 or L2<L1<L3.

7. The display substrate according to claim 6, characterized in that, L3 is greater than or equal to 1 micrometer.

8. The display substrate according to claim 1, characterized in that, In a direction perpendicular to the substrate, the distance between the photoelectric sensing unit and the substrate is different from the distance between the light-emitting unit and the substrate.

9. The display substrate according to claim 8, characterized in that, In a direction perpendicular to the substrate, the distance between the photoelectric sensing unit and the substrate is greater than the distance between the light-emitting unit and the substrate, and the distance difference is greater than 0.1 micrometers.

10. The display substrate according to claim 8, characterized in that, The pixel defining layer of the display substrate includes a first side surface adjacent to the photoelectric sensing unit and a second side surface adjacent to the light-emitting unit. The slope angle of the first side surface is θ1, and the slope angle of the second side surface is θ2, where θ1 < θ2.

11. The display substrate according to claim 10, characterized in that, θ1 is less than 25°, and θ2 is less than 50°.

12. The display substrate according to any one of claims 1-11, characterized in that, The refractive index of the lens unit is 1.6-3.

0.

13. The display substrate according to any one of claims 1-11, characterized in that, The first membrane layer includes: A first organic film layer is located on the side of the lens unit away from the substrate, the surface height of the first organic film layer is greater than the surface height of the lens unit, and the refractive index of the first organic film layer is less than the refractive index of the lens unit.

14. The display substrate according to any one of claims 1-11, characterized in that, The display substrate includes a plurality of sub-pixels arranged in an array. The plurality of sub-pixels includes a first sub-pixel column and a second sub-pixel column arranged alternately along a third direction. The first sub-pixel column includes red sub-pixels and blue sub-pixels arranged alternately along a fourth direction. The second sub-pixel column includes a plurality of green sub-pixels arranged at intervals along the fourth direction. The photoelectric sensing unit is located between adjacent green sub-pixels. The third direction is perpendicular to the fourth direction.

15. The display substrate according to any one of claims 1-11, characterized in that, The orthographic projection of the lens unit onto the substrate is a circle or a rectangle.

16. A display device, characterized in that, Includes the display substrate as described in any one of claims 1-15.

17. A method for manufacturing a display substrate, characterized in that, include: Provide substrates; A light-emitting unit and a photoelectric sensing unit are formed on the substrate. The photoelectric sensing unit is used to generate an electrical signal based on the light emitted by the light-emitting unit and transmit the electrical signal to the recognition circuit. The recognition circuit is used to connect to the fingerprint recognition chip and transmit the received electrical signal to the fingerprint recognition chip. A lens unit is formed on the side of the photoelectric sensing unit away from the substrate. The lens unit corresponds to the photoelectric sensing unit one by one. The lens unit includes a convex surface that protrudes towards the side away from the substrate. The orthographic projection of the lens unit on the substrate overlaps with the orthographic projection of the photoelectric sensing unit on the substrate. The refractive index of the lens unit is greater than the refractive index of the first film layer, which is located on the side of the lens unit away from the substrate.

18. The method for manufacturing a display substrate according to claim 17, characterized in that, The light-emitting unit and the photoelectric sensing unit comprise: A planarization layer is formed on the substrate. The planarization layer is patterned to form a first planarization layer region and a second planarization layer region. In a direction perpendicular to the substrate, the distance between the first planarization layer region and the substrate is different from the distance between the second planarization layer region and the substrate. The photoelectric sensing unit is formed in the first planarization layer region, and the light-emitting unit is formed in the second planarization layer region.

19. The method for manufacturing a display substrate according to claim 17, characterized in that, The method further includes: A pixel defining layer is formed that defines the photoelectric sensing unit and the light-emitting unit. The pixel defining layer includes a first side surface adjacent to the photoelectric sensing unit and a second side surface adjacent to the light-emitting unit. The slope angle of the first side surface is θ1, and the slope angle of the second side surface is θ2, where θ1 < θ2.

20. The method for manufacturing a display substrate according to claim 17, characterized in that, The lens unit comprises: A second organic film layer is formed on the side of the photoelectric sensing unit away from the substrate, and the refractive index of the second organic film layer is less than the refractive index of the lens unit; The second organic film layer is patterned to form a groove, the groove including a concave surface that protrudes toward the side close to the substrate, the radius of curvature of the concave surface being smaller than the radius of curvature of the convex surface; The lens unit is formed within the groove.

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