Display substrate and display device

Abstract

The utility model provides a display substrate and a display device, and belongs to the technical field of display. The display substrate comprises a substrate body; the light-emitting unit and the photoelectric sensing unit are located on the substrate, the photoelectric sensing unit is used for generating an electric signal according to light emitted by the light-emitting unit and transmitting the electric signal to the identification circuit, and the identification circuit is used for being connected with a fingerprint identification chip and transmitting the received electric signal to the fingerprint identification chip; the lens units are located on the sides, away from the substrate, of the photoelectric sensing units, the lens units correspond to the photoelectric sensing units in a one-to-one mode, each lens unit comprises a convex face protruding towards the side, away from the substrate, of the corresponding lens unit, and orthographic projections of the lens units on the substrate and orthographic projections of the photoelectric sensing units on the substrate are overlapped; the refractive index of the lens unit is larger than that of the first film layer. The fingerprint identification precision can be improved.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and particularly refers to a display substrate and a display device. BACKGROUND

[0002] The array substrate of electronic products such as mobile phones and tablet computers usually has a display area for displaying images, and the display area has a fingerprint identification function.

[0003] In the related art, the display area includes a plurality of light emitting units (such as sub-pixel units), a plurality of organic photodiode (OPD) units, and a plurality of OPD circuits. The OPD units are located between the light emitting units, and the OPD units are connected to the OPD circuits one by one. The OPD circuits are connected to a fingerprint identification 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 an electrical signal according to the received light and transmit the electrical signal to the OPD circuits. The OPD circuits transmit the electrical signal to the fingerprint identification chip. The fingerprint identification chip performs fingerprint identification according to the electrical signals sent by the OPD circuits. SUMMARY

[0004] Embodiments of the present disclosure provide a display substrate and a display device, which can improve the fingerprint identification accuracy.

[0005] Embodiments of the present disclosure provide the technical solutions as follows:

[0006] In one aspect, a display substrate is provided, comprising:

[0007] a substrate;

[0008] a light emitting unit and a photoelectric sensing unit located on the substrate, the photoelectric sensing unit being configured to generate an electrical signal according to light emitted by the light emitting unit and transmit the electrical signal to an identification circuit, the identification circuit being configured to connect to a fingerprint identification chip and transmit the received electrical signal to the fingerprint identification chip;

[0009] a lens unit located on a side of the photoelectric sensing unit away from the substrate, the lens unit corresponding to the photoelectric sensing unit one by one, the lens unit including a convex surface protruding toward the side away from the substrate, a normal projection of the lens unit on the substrate overlapping a normal projection of the photoelectric sensing unit on the substrate, a refractive index of the lens unit being greater than a refractive index of a first film layer, the first film layer being located on a side of the lens unit away from the substrate.

[0010] In some embodiments, the first film layer is immediately adjacent to the lens unit.

[0011] In some embodiments, the lens unit further comprises a concave surface protruding towards the side close to the substrate.

[0012] 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.

[0013] In some embodiments, the orthographic projection of the photoelectric sensing unit on the substrate is within the orthographic projection of the corresponding lens unit on the substrate.

[0014] 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

[0015] In some embodiments, L3 is greater than or equal to 1 micrometer.

[0016] In some embodiments, 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.

[0017] 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 micrometer.

[0018] In some embodiments, the pixel defining layer comprises 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

[0019] In some embodiments, θ1 is less than 25° and θ2 is less than 50°.

[0020] In some embodiments, the refractive index of the lens unit is 1.6-3.0.

[0021] In some embodiments, the first film layer comprises:

[0022] a first organic film layer 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.

[0023] In some embodiments, 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, and the photoelectric sensing unit is located between adjacent green sub-pixels.

[0024] In some embodiments, a projection of the lens unit on the substrate is a circle or a rectangle.

[0025] Embodiments of the present disclosure also provide a display device including the display substrate as described above.

[0026] Embodiments of the present disclosure have the following beneficial effects:

[0027] In the above scheme, the lens unit is arranged on the side of the photoelectric sensing unit away from the substrate, and the refractive index of the lens unit is greater than the refractive index of the first film layer. Thus, after the light emitted by the display substrate is reflected by an external object such as a finger, the light passes through the first film layer and is incident on the photoelectric sensing unit after being refracted by the lens unit and being gathered towards the central axis of the lens unit. This makes the reflected light of the fingerprint incident on the surface of the photoelectric sensing unit as much as possible, increases the light receiving amount of the photoelectric sensing unit, generates more photoelectric current, and thus improves the fingerprint recognition accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 And Figure 2 FIG. 1 is a structural schematic diagram of a display substrate according to an embodiment of the present disclosure;

[0029] Figure 3 FIG. 4 is a schematic diagram in which the central axis of the lens unit coincides with the central axis of the photoelectric sensing unit according to an embodiment of the present disclosure;

[0030] Figure 4 FIG. 5 is a schematic diagram in which the lens unit is arranged between adjacent green sub-pixels according to an embodiment of the present disclosure;

[0031] Figure 5 FIG. 6 is a schematic diagram of light propagation in the display substrate according to an embodiment of the present disclosure;

[0032] Figure 6 FIG. 7 is a schematic diagram in which light incident on the lens not parallel to the main optical axis is gathered to a secondary focal point;

[0033] Figures 7-10 FIG. 8 is a schematic diagram in which the central axis of the lens unit is at a distance from the central axis of the photoelectric sensing unit according to an embodiment of the present disclosure;

[0034] Figures 11-17 A schematic diagram of a display substrate made for embodiments of the present disclosure.

[0035] Reference signs

[0036] 01 Substrate substrate

[0037] 02 Barrier layer

[0038] 03 Light shielding metal layer

[0039] 04 First insulating layer

[0040] 05 Active layer

[0041] 06 Second insulating layer

[0042] 07 / 08 Gate metal layer

[0043] 09 Third insulating layer

[0044] 10 Fourth insulating layer

[0045] 11 Source / drain metal layer

[0046] 12 Planarization layer

[0047] 13 Pixel definition layer

[0048] 131 First side surface

[0049] 132 Second side surface

[0050] 14 Organic encapsulation layer

[0051] 15 Second inorganic encapsulation layer

[0052] 16 First touch insulation layer

[0053] 17 Second touch insulation layer

[0054] 18 Second organic film layer

[0055] 181 Groove

[0056] 19 First organic film layer

[0057] 20 Light emitting unit

[0058] 21 Anode of light emitting unit

[0059] 22 Organic functional layer of light emitting unit

[0060] 23 Cathode of light emitting unit

[0061] 24 First inorganic encapsulation layer

[0062] 30 photoelectric sensing units

[0063] Anode of 31 photoelectric sensing unit

[0064] Organic functional layer of 32 photoelectric sensing units

[0065] Cathode of 33 photoelectric sensing unit

[0066] 40 Package Structure

[0067] 41 Touch Function Layer

[0068] 42 Lens Units

[0069] 421 Convex surface

[0070] 422 Concave surface

[0071] 43 Objects to be identified Detailed Implementation

[0072] 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.

[0073] 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, 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 and display device that can improve fingerprint recognition accuracy.

[0074] Embodiments of this disclosure provide a display substrate, comprising:

[0075] Substrate;

[0076] 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.

[0077] 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.

[0078] In some embodiments, the first film layer is adjacent to the lens unit.

[0079] 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.

[0080] Figure 1 and Figure 2 This is a schematic diagram of the structure of a display substrate according to an embodiment of the present disclosure; as shown Figure 1 and Figure 2 As shown, the display substrate includes a display backplane and light-emitting units 20 and photoelectric sensing units 30 disposed on the display backplane. 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, source / drain metal layers 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.

[0081] The light-emitting unit 20 comprises an anode 21, an organic functional layer 22 and a cathode 23; the photoelectric sensing unit 30 comprises 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 arranged 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 arranged 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 arranged in the same layer and with the same material as the cathode 23 of the light-emitting unit 20.

[0082] As shown in Figure 1 and Figure 2 , the light-emitting unit 20 and the photoelectric sensing unit 30 are further provided with an encapsulation layer on the side away from the substrate 01, the encapsulation layer comprises a first inorganic encapsulation layer 24, an organic encapsulation layer 14 and a second inorganic encapsulation layer 15; a touch structure is further provided on the side of the encapsulation layer away from the substrate 01, the touch structure comprises a touch functional layer 41, a first touch insulation layer 16 and a second touch insulation layer 17; and an encapsulation structure 40 is further provided on the side of the touch structure away from the substrate 01, the encapsulation structure 40 can be composed of multiple composite films, including a polarizer, an optical adhesive layer and a glass cover plate, etc.

[0083] In the embodiment, as shown in Figure 1 and Figure 2 , a second organic film layer 18, a lens unit 42 and a first organic film layer 19 are provided on the side of the photoelectric sensing unit 30 away from the substrate 01, and the central axis of the photoelectric sensing unit 30 coincides with the central axis (i.e. the main 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 index of the second organic film layer 18 and the first organic film layer 19 can be less than 1.6, the refractive index of the lens unit 42 can be 1.6-3.0, and the surface height of the side of the lens unit 42 away from the substrate 01 is not greater than the surface height of the side of the first organic film layer 19 away from the substrate 01.

[0084] As shown in Figure 1 , the light emitted by the light-emitting unit 20 is irradiated onto the object to be identified 43 (such as a fingerprint), passes through the first organic film layer 19 and is irradiated onto 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 irradiated onto the surface of the lens unit 42 can be refracted and gathered towards the direction of the central axis of the lens unit 42, and then is incident onto the photoelectric sensing unit 30, so that the reflected light of the fingerprint is incident onto the surface of the photoelectric sensing unit 30 as much as possible, the light receiving amount of the photoelectric sensing unit 30 is increased, the photoelectric sensing unit 30 generates more photoelectric current, and the fingerprint recognition accuracy is improved.

[0085] 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.

[0086] like Figure 2 As shown, 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.

[0087] like Figure 2 As shown, 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.

[0088] 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.

[0089] like Figure 3As shown, 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; ​​and 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.

[0090] 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.

[0091] In some embodiments, such as Figure 2 As shown, in the direction perpendicular to the substrate 01, the distance between the photoelectric sensing unit 30 and 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.

[0092] In this embodiment, as Figure 2 As shown, 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.

[0093] 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.

[0094] In some embodiments, the display substrate includes a plurality of sub-pixels arranged in an array, such as Figure 4 As shown, 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 placement 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 may be located between adjacent green sub-pixels P2. The third direction is perpendicular to the fourth direction. Figures 1-2 for Figure 4 A schematic diagram of the cross-section along the AA' direction is shown.

[0095] like Figure 5 As shown, 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 Figure 6 As shown, when light that is not parallel to the principal optical axis enters the lens structure, it will be focused to the secondary focal point and will not be focused to the principal focal point.

[0096] 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) can be 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. Figure 7 As shown, 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. Figure 8 As shown, 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. Figure 9As shown, by designing the main optical axis of the lens unit 42 to be offset relative to the central axis of the photosensitive unit 30, it is possible to prevent large-angle reflected light from being converged outside the photosensitive unit 30, to improve the light signal receiving amount of the photosensitive unit 30, and thus to improve the recognition accuracy. Of course, the value of d1 cannot be too large, and needs to be less than 1 / 2 of the width of the photosensitive unit 30 in the first direction. If the value of d1 is too large, the light convergence degree of the lens unit 42 will decrease, and the signal enhancement effect cannot be achieved.

[0097] In some embodiments, the main 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 photosensitive unit 30. For example, as shown in FIG. 3, the main optical axis of the lens unit 42 can be offset relative to the central axis of the photosensitive unit 30 in the first direction and the second direction. Figure 10 As shown, the photosensitive unit 30 is symmetrical relative to the symmetry axis 1 and the symmetry axis 2; the lens unit 42 is symmetrical relative to the symmetry axis 1' and the symmetry axis 2'; the distance between the symmetry axis 1' and the symmetry axis 1 in the first direction is d1, and the distance between the symmetry axis 2' and the symmetry axis 2 in the second direction is d2, and d1 and d2 are greater than 0 microns. Of course, the values of d1 and d2 cannot be too large, and need to be less than 1 / 2 of the width of the photosensitive unit 30 in the first direction. If the values of d1 and d2 are too large, the light convergence degree of the lens unit 42 will decrease, and the signal enhancement effect cannot be achieved.

[0098] Embodiments of the present disclosure also provide a display device including the display substrate as described above.

[0099] The display device includes, but is not limited to, 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, a power supply, and the like. Those skilled in the art can understand that the structure of the display device described above does not constitute a limitation on the display device, and the display device can include more or fewer components described above, or combine certain components, or different component arrangements. In the embodiments of the present disclosure, the display device includes, but is not limited to, a display, a mobile phone, a tablet computer, a television, a wearable electronic device, a navigation display device, and the like.

[0100] The display device can be a television, a display, a digital photo frame, a mobile phone, a tablet computer, or any product or component with a display function. The display device further includes a flexible circuit board, a printed circuit board, and a back plate.

[0101] Embodiments of the present disclosure also provide a manufacturing method of a display substrate, including:

[0102] A substrate is provided;

[0103] forming a light emitting unit and a photoelectric sensing unit on the substrate, the photoelectric sensing unit being used to generate an electrical signal according to the light emitted by the light emitting unit and transmit the electrical signal to an identification circuit, the identification circuit being used to connect a fingerprint identification chip and transmit the received electrical signal to the fingerprint identification chip;

[0104] forming a lens unit on a side of the photoelectric sensing unit away from the substrate, the lens unit corresponding to the photoelectric sensing unit one by one, the lens unit including a convex surface protruding toward the side away from the substrate, a normal projection of the lens unit on the substrate overlapping a normal projection of the photoelectric sensing unit on the substrate, a refractive index of the lens unit being greater than a refractive index of a first film layer on the side of the lens unit away from the substrate.

[0105] In the embodiment, the lens unit is formed on a side of the photoelectric sensing unit away from the substrate, and the refractive index of the lens unit is greater than the refractive index of the first film layer. In this way, after the light emitted by the display substrate is reflected by an external object such as a finger, the light passes through the first film layer and irradiates the lens unit, is refracted, is gathered toward the central axis of the lens unit, and then is incident on the photoelectric sensing unit. This makes the fingerprint reflected light as much as possible to be incident on the surface of the photoelectric sensing unit, increases the light receiving amount of the photoelectric sensing unit, generates more photoelectric current, and then improves the fingerprint identification accuracy.

[0106] In some embodiments, the manufacturing method of the embodiment includes the following steps:

[0107] Step 1, as shown in Figure 11 forming a display backplane and an anode 31 of a light emitting unit 20 and an anode 21 of a photoelectric sensing unit 30 on the display backplane, and forming a pixel definition layer 13;

[0108] 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.

[0109] 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.

[0110] During the patterning of the planarization layer 12, a layer with a thickness of approximately [thickness missing] 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.

[0111] In addition, when forming the pixel defining layer 13, a gray-tone mask or a half-tone 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 photosensitive 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°, so as to ensure the leveling of the inkjet-printed organic material layer during encapsulation. Of course, the smaller the values of θ1 and θ2, the better the leveling of the inkjet-printed organic material layer, if the process allows.

[0112] Step 2, as shown in Figure 12 , the organic functional layer 32 of the photosensitive sensing unit 30, the cathode 33, the organic functional layer 22 of the light emitting unit 20, the cathode 23, the first inorganic encapsulation layer 24, and the organic encapsulation layer 14 are formed;

[0113] In order to simplify the structure and manufacturing process of the display substrate, the organic functional layer 32 of the photosensitive sensing unit 30 can be arranged 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 photosensitive sensing unit 30 can be arranged in the same layer and with the same material as the cathode 23 of the light emitting unit 20.

[0114] Step 3, as shown in Figure 13 , the second inorganic encapsulation layer 15 is formed; and a touch structure including the touch functional layer 41, the first touch insulating layer 16, and the second touch insulating layer 17 is formed on the side of the encapsulation layer away from the substrate 01;

[0115] Step 4, as shown in Figure 14 , the second organic film layer 18 is formed, the refractive index of the second organic film layer 18 is less than 1.6, and the second organic film layer 18 can be patterned by using a gray-tone mask or a half-tone mask to form a groove 181, the groove 181 includes a concave surface protruding towards the side close to the substrate 01, and the curvature radius of the concave surface is smaller than the curvature radius of the convex surface of the lens unit 42;

[0116] 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, and then the high-refractive-index material layer can be patterned by using a gray-tone mask or a half-tone mask to form the lens unit 42 in the groove;

[0117] In this embodiment, as shown in Figures 1-2 , the central axis of the photosensitive sensing unit 30 can coincide with the central axis (i.e., the main optical axis) of the lens unit 42.

[0118] The boundary of the photoelectric sensing unit 30 can be inwardly or outwardly extended 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 many light rays as possible, the orthographic projection of the lens unit 42 on the substrate substrate 01 covers the orthographic projection of the photoelectric sensing unit 30 on the substrate substrate 01, i.e. the orthographic projection of the photoelectric sensing unit 30 on the substrate substrate 01 is located within the orthographic projection of the corresponding lens unit 42 on the substrate substrate 01.

[0119] As shown in FIG. 1, the photoelectric sensing unit 30 and the lens unit 42 are both symmetrical relative to the symmetry axis 1 and the symmetry axis 2, the shortest distance between the boundary of the photoelectric sensing unit 30 and the boundary of the convex surface 421 in the first direction parallel to the substrate 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, and 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, wherein L1≤L2<L3 or L2<L1<L3. In order to ensure that the lens unit 42 converges as many light rays as possible, L3 can be greater than or equal to 1 micrometer. Figure 3 As shown in FIG. 1, the light emitted by the light emitting unit 20 is reflected by the object to be identified 43 at a certain angle, and part of the large-angle reflected light (not parallel to the principal axis of the lens unit 42) is converged to the outside of the photoelectric sensing unit 30 after entering the lens unit 42, resulting in that the photoelectric sensing unit 30 cannot receive sufficient light signals, and there is a risk of reducing the identification accuracy. This is because, as shown in FIG. 2, when a light incident not parallel to the principal axis enters the lens structure, it will be focused to the secondary focal point, and will not be focused to the primary focal point.

[0120] Figure 5 In order to make the photoelectric sensing unit 30 receive sufficient light signals and ensure the identification accuracy, in the embodiment, the principal axis of the lens unit 42 (i.e. the central axis of the lens unit 42) can be designed to be offset relative to the central axis of the photoelectric sensing unit 30, so that the large-angle reflected light can be converged into the photoelectric sensing unit 30, the light signal receiving amount of the photoelectric sensing unit 30 is improved, and thus the identification accuracy is improved. As shown in FIG. 3, the photoelectric sensing unit 30 is symmetrical relative to the symmetry axis 1 and the symmetry axis 2; the lens unit 42 is symmetrical relative to the symmetry axis 1' and the symmetry axis 2; and the distance between the symmetry axis 1' and the symmetry axis 1 in the first direction is d1. As shown in FIG. 4, the distance between the central axis of the photoelectric sensing unit 30 and the central axis of the lens unit 42 is d1, and d1>0 micrometers. Figure 6

[0121] In order to make the photoelectric sensing unit 30 receive sufficient light signals and ensure the identification accuracy, in the embodiment, the principal axis of the lens unit 42 (i.e. the central axis of the lens unit 42) can be designed to be offset relative to the central axis of the photoelectric sensing unit 30, so that the large-angle reflected light can be converged into the photoelectric sensing unit 30, the light signal receiving amount of the photoelectric sensing unit 30 is improved, and thus the identification accuracy is improved. As shown in FIG. 3, the photoelectric sensing unit 30 is symmetrical relative to the symmetry axis 1 and the symmetry axis 2; the lens unit 42 is symmetrical relative to the symmetry axis 1' and the symmetry axis 2; and the distance between the symmetry axis 1' and the symmetry axis 1 in the first direction is d1. As shown in FIG. 4, the distance between the central axis of the photoelectric sensing unit 30 and the central axis of the lens unit 42 is d1, and d1>0 micrometers. Figure 7 Figure 8 Figure 9 ​​​​As shown, by offsetting the principal optical axis of the lens unit 42 relative to the central axis of the photoelectric sensing unit 30, it is possible to prevent large-angle reflected light from being focused outside the photoelectric sensing unit 30, thereby increasing the amount of light signal received by the photoelectric sensing unit 30 and 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 focusing power of the lens unit 42 will decrease, and it will not achieve the effect of signal enhancement.

[0122] 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. For example... Figure 10 As shown, 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, and the distance between symmetry axes 2' and 2 in the second direction is d2, where d1 and d2 are greater than 0 micrometers. However, the values ​​of d1 and d2 cannot be too large; they must both be less than half 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 ability of the lens unit 42 will decrease, failing to achieve the signal enhancement effect.

[0123] Step 6, as follows Figure 16 As shown, after the lens unit 42 is formed, 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.

[0124] Step 7, as follows Figure 17 As shown, an encapsulation structure 40 is formed. The encapsulation structure 40 can be composed of multiple composite film materials, including a polarizer, an optical adhesive layer, and a glass cover.

[0125] 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.

[0126] 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.

[0127] It should be noted that each of the embodiments in the present specification is described in a progressive manner, and the same or similar parts between each embodiment can be mutually referred to, and each embodiment focuses on the difference from other embodiments. In particular, for the embodiments, since they are basically similar to the product embodiments, they are described more simply, and the relevant parts can be referred to the part of the product embodiments.

[0128] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning of those skilled in the art to which the present disclosure pertains. The terms "first", "second", and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include", "comprise", and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connected" or "coupled" or similar terms do not mean only physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right", and the like are used only to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships can also be changed accordingly.

[0129] It can be understood that when an element such as a layer, a film, a region, or a substrate is referred to as being "on" or "under" another element, it can be "directly" on or under the other element, or an intervening element can also be present.

[0130] In the description of the above-described embodiments, specific features, structures, materials, or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0131] The above description is merely a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present disclosure, and all should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection 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.

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