Display substrate, display device and fingerprint identification method

Abstract

The display substrate, the display device and the fingerprint identification method provided by the present disclosure comprise a substrate substrate; a plurality of light emitting devices arranged in an array on the substrate substrate; a plurality of photosensitive devices located between the layer where the light emitting devices are located and the substrate substrate; the orthographic projection of each photosensitive device on the substrate substrate and the orthographic projection of the gap of the adjacent light emitting devices overlap each other; a black matrix located on the side of the layer where the light emitting devices are located away from the substrate substrate; the orthographic projection of the black matrix on the substrate substrate and the orthographic projection of the gap of the adjacent light emitting devices overlap each other, the black matrix has a plurality of first openings, the orthographic projection of the first opening on the substrate substrate and the orthographic projection of the photosensitive device overlap each other; the total amount of light irradiated to the photosensitive device through the first opening meets the signal-to-noise ratio of fingerprint identification and is less than the full well capacity of the photosensitive device.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, and in particular to a display substrate, a display device and a fingerprint identification method. BACKGROUND

[0002] With the continuous development of terminal technology, electronic devices are applied more and more widely. In order to protect the information security of users, the use of fingerprint identification function on electronic devices is becoming more and more common, such as for mobile phone unlocking, mobile payment (such as payment, transfer) and the like. SUMMARY

[0003] The present disclosure provides a display substrate, a display device and a fingerprint identification method, and the specific solutions are as follows:

[0004] In one aspect, the present disclosure provides a display substrate, comprising:

[0005] a substrate substrate;

[0006] a plurality of light emitting devices arranged in an array on the substrate substrate;

[0007] a plurality of light sensitive devices located between the layer where the light emitting devices are located and the substrate substrate; the orthographic projection of each light sensitive device on the substrate substrate and the orthographic projection of the gap of adjacent light emitting devices overlap with each other;

[0008] a black matrix located on the side of the layer where the light emitting devices are located away from the substrate substrate; the orthographic projection of the black matrix on the substrate substrate and the orthographic projection of the gap of adjacent light emitting devices overlap with each other, the black matrix has a plurality of first openings, the orthographic projection of the first opening on the substrate substrate and the orthographic projection of the light sensitive device overlap with each other; the total amount of light irradiated to the light sensitive device through the first opening meets the signal-to-noise ratio of fingerprint identification and is less than the full well capacity of the light sensitive device.

[0009] In some embodiments, in the above-mentioned display substrate provided by the present disclosure, the first opening and the photoelectric conversion layer of the light sensitive device are one-to-one corresponding and overlapping, and the center of the orthographic projection of the first opening on the substrate substrate substantially coincides with the center of the orthographic projection of the photoelectric conversion layer contained in the corresponding light sensitive device.

[0010] In some embodiments, in the above-mentioned display substrate provided by the present disclosure, the orthographic projection of the first opening on the substrate substrate is located within the orthographic projection of the photoelectric conversion layer contained in the corresponding light sensitive device.

[0011] In some embodiments, in the above-mentioned display substrate provided by the present disclosure, the optical comprehensive transmittance T of the light reaching the light sensitive device through the finger and the first opening satisfies the following relationship:

[0012] 0 < T < k * K s *K L ;

[0013] wherein k is a coefficient, K S is a ratio of a width of the first opening to a width of a photoelectric conversion layer corresponding to the photosensitive device in a row direction, K L is a ratio of a length of the first opening to a length of the photoelectric conversion layer corresponding to the photosensitive device in a column direction.

[0014] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, a light receiving angle a determined by the first opening satisfies the following relationship:

[0015] a = arctan[P / (2h1)], 0 < (D LPIN + D LBM ) / (2*h2) < a;

[0016] wherein P is a distance between two adjacent valley centers or two adjacent ridge centers of a fingerprint, h1 is a distance from a contact surface of a finger to the black matrix of the display substrate, h2 is a distance from the black matrix to the photosensitive device, D LPIN is a length of the photoelectric conversion layer of the photosensitive device in the column direction, D LBM is a length of the first opening in the column direction.

[0017] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, 0 < k < 0.4, 0 < K S < 0.75, 0 < K L < 0.75, 8 pm ≤ D LPIN ≤ 40 pm, 50 pm ≤ h1 ≤ 200 pm, 8 pm ≤ h2 ≤ 20 pm, 300 pm ≤ P ≤ 500 pm, 8 pm ≤ D SPIN ≤ 20 pm, D SPIN is a width of the photoelectric conversion layer of the photosensitive device in the row direction.

[0018] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, further comprising a red resin filling the first opening;

[0019] A normal projection of the first opening on the substrate substrate is greater than or equal to a normal projection of a photoelectric conversion layer corresponding to the photosensitive device.

[0020] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, a ratio of a width of the first opening to a width of the photoelectric conversion layer of the light-sensitive device in the row direction is greater than or equal to 1 and less than 2, and a ratio of a length of the first opening to a length of the photoelectric conversion layer of the light-sensitive device in the column direction is greater than or equal to 1 and less than 2.

[0021] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, further comprising: a plurality of color resist located on a side of the black matrix away from the substrate, the color resist comprising a red color resist, the red color resist being same layer and same material as the red resin.

[0022] The black matrix further comprises a plurality of second openings, the color resist is located at the second opening, and the orthographic projection of the color resist on the substrate and the orthographic projection of the light-emitting device overlap each other.

[0023] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, in the same row, every three adjacent light-sensitive devices are a first light-sensitive device, a second light-sensitive device and a third light-sensitive device, respectively, and the column where the first light-sensitive device is located is between the column where the second light-sensitive device is located and the column where the second light-sensitive device is located in adjacent two rows.

[0024] In the first light-sensitive device, the second light-sensitive device and the third light-sensitive device adjacent in the same row:

[0025] The bottom electrode of the first light-sensitive device is independent of the bottom electrode of the second light-sensitive device and the bottom electrode of the third light-sensitive device, and the bottom electrode of the second light-sensitive device is electrically connected to the bottom electrode of the third light-sensitive device.

[0026] The area of the photoelectric conversion layer of the light-sensitive device that is not blocked by the anode of the light-emitting device is the effective photosensitive area, and the effective photosensitive area of the first light-sensitive device is equal to the sum of the effective photosensitive area of the second light-sensitive device and the effective photosensitive area of the third light-sensitive device.

[0027] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, the orthographic projection of the photoelectric conversion layer of the light-sensitive device on the substrate and the edge of the orthographic projection of the anode of the light-emitting device extending in the column direction overlap each other.

[0028] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, the orthographic projection of the photoelectric conversion layer of the light-sensitive device on the substrate and the orthographic projection of the anode of the light-emitting device do not overlap each other.

[0029] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, the orthographic projection of the photoelectric conversion layer of the light-sensitive device on the substrate is a rectangle.

[0030] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, the photoelectric conversion layer of the first photosensitive device comprises a first photoelectric conversion layer and a second photoelectric conversion layer which are independent of each other.

[0031] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, the photoelectric conversion layer of the first photosensitive device comprises a first photoelectric conversion layer and a second photoelectric conversion layer which are independent of each other.

[0032] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, further comprising a touch grid layer between the layer where the light emitting device is located and the black matrix, the orthographic projection of the touch grid layer on the substrate is located within the orthographic projection of the black matrix, and the orthographic projection of the touch grid layer on the substrate does not overlap with the orthographic projection of the photoelectric conversion layer of the photosensitive device.

[0033] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, the area where any grid of the touch grid layer is located is provided with one photoelectric conversion layer of the photosensitive device or one effective light emitting layer of the light emitting device.

[0034] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, the grid line width of the touch grid layer extending along the column direction is half of the grid line width extending along other directions.

[0035] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, the area where any grid of the touch grid layer is located is provided with one photoelectric conversion layer of the photosensitive device and one effective light emitting layer of the light emitting device.

[0036] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, the grid line width of the touch grid layer extending in each direction is substantially equal.

[0037] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, further comprising an ultra-thin glass cover plate on the side of the black matrix away from the substrate.

[0038] In another aspect, the embodiments of the present disclosure also provide a display device comprising the display substrate provided by the embodiments of the present disclosure.

[0039] In another aspect, the embodiments of the present disclosure also provide a fingerprint identification method, comprising:

[0040] Detecting the brightness of ambient light;

[0041] Determine if the ambient light brightness is greater than the preset brightness. If so, use the ambient light for fingerprint recognition; otherwise, use the emitted light from the light-emitting device for fingerprint recognition. Attached Figure Description

[0042] Figure 1 This is a schematic diagram of the structure of a display substrate provided in an embodiment of this disclosure;

[0043] Figure 2 For along Figure 1 A schematic diagram of a cross-sectional structure of the Middle I-II line;

[0044] Figure 3 for Figure 2 The diagram shown illustrates fingerprint recognition using light emitted by a light-emitting device on a display substrate.

[0045] Figure 4 for Figure 1 A schematic diagram of a structure in region Z shown;

[0046] Figure 5 for Figure 1 Another structural diagram of region Z shown;

[0047] Figure 6 for Figure 1 Another structural diagram of region Z shown;

[0048] Figure 7 A dimensional relationship diagram between the first opening and the photoelectric conversion layer provided in an embodiment of this disclosure;

[0049] Figure 8 The graph shows the relationship between the dimensions of the first opening and the photoelectric conversion layer and the overall optical transmittance.

[0050] Figure 9 Provided for the embodiments of this disclosure Figure 2 The diagram shown illustrates the fingerprint imaging principle of the display substrate.

[0051] Figure 10 Another dimensional relationship diagram between the first opening and the photoelectric conversion layer provided in the embodiments of this disclosure;

[0052] Figure 11 For along Figure 1 Another cross-sectional structural diagram of the Middle I-II line;

[0053] Figure 12 Another dimensional relationship diagram between the first opening and the photoelectric conversion layer provided in the embodiments of this disclosure;

[0054] Figure 13 for Figure 1 Another structural diagram of region Z shown;

[0055] Figure 14 Fig. 7 shows another structural schematic diagram of the Z region; Figure 1 Fig. 8 shows another structural schematic diagram of the Z region;

[0056] Figure 15 Fig. 9 shows another cross-sectional structural schematic diagram along the I-II line; Figure 1 Fig. 10 shows another cross-sectional structural schematic diagram along the I-II line;

[0057] Figure 16 Fig. 11 shows a flowchart of a fingerprint identification method provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0058] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings of the embodiments of the present disclosure. It should be noted that the sizes and shapes of the figures in the drawings do not reflect the true proportions, but only serve to illustrate the present disclosure. And the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout.

[0059] Unless otherwise defined, the technical terms or scientific terms used herein should be understood as the usual meanings understood by a person with ordinary skills in the art to which the present disclosure belongs. The terms "first", "second" and the like used in the specification and claims of the present disclosure do not represent any order, number or importance, but are only used to distinguish different components. The terms "include", "contain" and the like mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, without excluding other elements or objects. "In", "out", "up", "down" and the like are only used to represent relative positional relationships, which may change accordingly when the absolute positions of the described objects change.

[0060] The optical fingerprint identification principle in the related art is as follows: when a finger is placed above a display product, the emitted light of the light emitting device contained in the display product irradiates the positions of the valleys and ridges of the finger, and then enters the light sensitive device contained in the display product after being reflected by the valleys and ridges of the finger. Since the light intensities reflected by the positions of the valleys and ridges are different, the light sensitive device generates different electrical signals according to the difference in the above reflected light intensities, thereby realizing fingerprint identification. It can be seen that the display light is used as the light source in the related art, but the light greater than 600nm in the external environment light will pass through the finger and irradiate the light sensitive device, thereby interfering with the fingerprint imaging quality and affecting the user experience.

[0061] In order to improve the above technical problems existing in the related art, the present disclosure provides a display substrate, as shown in Figures 1 to 3 which comprises:

[0062] a substrate 101;

[0063] Multiple light-emitting devices 102 are arranged in an array on the substrate 101;

[0064] Multiple photosensitive devices 103 are located between the layer containing the light-emitting device 102 and the substrate 101; the orthographic projection of each photosensitive device 103 on the substrate 101 overlaps with the orthographic projection of the gap between adjacent light-emitting devices 102.

[0065] The black matrix 104 is located on the side of the layer where the light-emitting device 102 is located, away from the substrate 101. The orthographic projection of the black matrix 104 on the substrate 101 overlaps with the orthographic projection of the gap between adjacent light-emitting devices 102. The black matrix 104 has multiple first openings K1. The orthographic projection of the first openings K1 on the substrate 101 overlaps with the orthographic projection of the photosensitive device 103. The total amount of light irradiating the photosensitive device 103 through the first openings K1 meets the signal-to-noise ratio (SNR) of fingerprint recognition and is less than the full-well capacity of the photosensitive device 103. The incident light of the first openings K1 is either ambient light transmitted through the finger or emitted light from the light-emitting device 102 reflected by the finger.

[0066] In the display substrate provided in this embodiment, the interaction between the first opening K1 and the photosensitive device 103 below it allows for fingerprint recognition when the total amount of ambient light passing through the finger F and the first opening K1 and illuminating the photosensitive device 103 meets the signal-to-noise ratio requirement for fingerprint recognition and is less than the full-well capacity of the photosensitive device 103. When the ambient light is too weak to meet the signal-to-noise ratio requirement, fingerprint recognition can be performed using the emitted light from the light-emitting device 102. Therefore, the display substrate provided in this disclosure is compatible with both ambient light and display light for fingerprint recognition, which improves user experience and enhances the core competitiveness of the product.

[0067] In some embodiments, such as Figure 2 and Figure 3 As shown, the photosensitive device 103 provided in this embodiment may include a bottom electrode a, a photoelectric conversion layer PIN, and a top electrode b stacked together. The photoelectric conversion layer PIN may include a P-type semiconductor layer, an I-type semiconductor layer (also called an intrinsic semiconductor layer), and an N-type semiconductor layer stacked together. The photoelectric conversion layer PIN and the top electrode b can be formed using a single patterning process. Optionally, to reduce leakage current, the orthographic projection of the top electrode b onto the substrate 101 needs to be slightly smaller than the orthographic projection of the photoelectric conversion layer PIN onto the substrate 101. For example, the distance between the boundary of the orthographic projection of the second electrode onto the substrate 101 and the boundary of the orthographic projection of the photoelectric conversion layer PIN onto the substrate 101 can be 0.5 μm to 2 μm.

[0068] In some embodiments, such as Figure 2 and Figure 3As shown, the light-emitting device 102 provided by the embodiment of the present disclosure can include an anode A, a light-emitting functional layer EL and a cathode C arranged in a stack, wherein the light-emitting functional layer EL can include but is not limited to a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting material layer, a hole blocking layer, an electron transport layer and an electron injection layer, and the light-emitting functional layer EL located in the pixel opening of the pixel defining layer 105 is the effective light-emitting layer of the light-emitting device 102. The light-emitting device 102 includes but is not limited to a red light device, a green light device and a blue light device.

[0069] In some embodiments, as Figures 1 to 3 As shown, the black matrix 104 provided by the embodiment of the present disclosure can also include a second opening K2 which is mutually overlapped with the light-emitting device 102 in orthographic projection, and the color resist 106 is arranged in the second opening K2. Optionally, in order to improve the color purity, the orthographic projection of the color resist 106 on the substrate 101 covers and is larger than the orthographic projection of the effective light-emitting layer of the light-emitting device 102 on the substrate 101. Optionally, the color resist 106 can include a red light color resist R, a green light color resist G and a blue light color resist B, wherein the red light device is below the red light color resist R, the green light device is below the green light color resist G, and the blue light device is below the blue light color resist B.

[0070] In some embodiments, in the above-mentioned display substrate provided by the embodiment of the present disclosure, as Figures 4 to 6 As shown, the first opening K1 is arranged in one-to-one correspondence with the photoelectric conversion layer PIN of the photosensitive device 103 in orthographic projection, and the center of the orthographic projection of the first opening K1 on the substrate 101 substantially coincides with the center of the orthographic projection of the photoelectric conversion layer PIN contained in the corresponding photosensitive device 103, so that the light transmitted by each first opening K1 has a better collimation effect, and the transmitted light is completely irradiated onto the corresponding photoelectric conversion layer PIN, thereby improving the fingerprint imaging quality.

[0071] It should be noted that in the embodiments provided by the present disclosure, due to the limitation of process conditions or the influence of other factors such as measurement, the above-mentioned "substantially" can be completely equivalent, or there can be some deviation, therefore, as long as the error (for example, a floating of 5% up and down, or a distance of 0 μm-1 μm deviation) is allowed, the above-mentioned "substantially" relationship belongs to the protection scope of the present disclosure.

[0072] In some embodiments, in the above-mentioned display substrate provided by the embodiment of the present disclosure, as Figures 4 to 7As shown, the orthographic projection of the first opening K1 on the substrate 101 can be located within the orthographic projection of the photoelectric conversion layer PIN contained in the photosensitive device 103. By matching the size of the photoelectric conversion layer PIN, the first opening K1 with a smaller size is set, which can effectively adjust the total amount of light transmitted through the first opening K1, so that the total amount of light received by the photoelectric conversion layer PIN under the first opening K1 meets the signal-to-noise ratio of fingerprint identification, and is less than the full well capacity of the photosensitive device 103, thereby the fingerprint information can be obtained through the photosensitive device 103.

[0073] It should be noted that in the related art, in order to avoid the interference of ambient light, a green resin is usually added above the photosensitive device 103, thereby increasing the production cost and reducing the product competitiveness. In the above embodiment, by adjusting the size of the first opening K1, the ambient light can be effectively utilized for fingerprint identification, avoiding the setting of the green resin, saving the production cost, and improving the product competitiveness.

[0074] Since the size of the first opening K1 is positively correlated with the total amount of light transmitted through it, when the brightness of the ambient light is particularly large (for example, greater than or equal to 10 W lx), a first opening with a smaller size can be set to match it, so that the total amount of ambient light transmitted through the first opening K1 and irradiated onto the photosensitive device 103 will not exceed the full well capacity of the photosensitive device 103. However, due to the influence of factors such as current manufacturing process and equipment precision, the smaller the size of the first opening K1, the more difficult it is to manufacture, and even the first opening K1 cannot be made.

[0075] Therefore, the size of the first opening K1 cannot be too small, and while ensuring the size of the first opening K1, in order to prevent the total amount of light transmitted through the finger and the first opening K1 and irradiated onto the photosensitive device 103 from exceeding the full well capacity of the photosensitive device 103 due to the brightness of the ambient light being too large, causing fingerprint identification to be impossible, as shown in Figure 7 and Figure 8 As shown, the optical comprehensive transmittance T of the ambient light in the present disclosure transmitted through the finger and the first opening K1 to reach the photosensitive device 103 needs to meet the following relationship:

[0076] 0 < T < k * K s * K L ;

[0077] Wherein, k is a coefficient, K S is the ratio of the width of the first opening K1 to the photoelectric conversion layer PIN of the corresponding photosensitive device 103 in the row direction X, and K L is the ratio of the length of the first opening K1 to the photoelectric conversion layer PIN of the corresponding photosensitive device 103 in the column direction Y. Optionally, 0 < T < 0.15, preferably 0 < T ≤ 0.1267.

[0078] Correspondingly, as shown inFigure 9 As shown, the light receiving angle a determined by the first opening K1 satisfies the following relationship:

[0079] a = arctan [P / (2h1)], 0 < (D LPIN +D LBM ) / (2*h2) < a;

[0080] wherein P is the distance between the centers of two adjacent valleys or the centers of two adjacent ridges of the fingerprint, h1 is the distance from the contact surface of the finger to the black matrix 104 of the display substrate, h2 is the distance from the black matrix 104 to the photosensitive device 103, D LPIN is the length of the photoelectric conversion layer PIN of the photosensitive device 103 in the column direction Y, and D LBM is the length of the first opening K1 in the column direction Y.

[0081] In some embodiments, 0 < k < 0.4, 0 < K S < 0.75, 0 < K L < 0.75, 8 μm ≤ D LPIN ≤ 40 μm, 50 μm ≤ h1 ≤ 200 μm, 8 μm ≤ h2 ≤ 20 μm, 300 μm ≤ P ≤ 500 μm, the width D SPIN of the photoelectric conversion layer PIN of the photosensitive device 103 in the row direction X satisfies 8 μm ≤ D SPIN ≤ 20 μm, and the center distance p of adjacent first openings satisfies 20 μm ≤ p ≤ 80 μm, as shown. Figure 9

[0082] Table 1 shows the fingerprint evaluation data of the first opening K1 and the photoelectric conversion layer PIN at different scales. As can be seen from Table 1, when the ratio of the side length of the first opening K1 to the photoelectric conversion layer PIN is less than 0.75, the optical comprehensive transmittance T of the ambient light is less than 12.67%, and the ambient light can be used for fingerprint recognition.

[0083] Table 1

[0084]

[0085] In some embodiments, in the above display substrate provided by the embodiments of the present disclosure, as Figure 10 and Figure 11 ​As shown, in order to facilitate the manufacture of the first opening K1, the size of the first opening K1 can be large, and specifically, the orthographic projection of the first opening K1 on the substrate 101 can be greater than or equal to the orthographic projection of the photoelectric conversion layer PIN of the corresponding photosensitive device 103. In order to avoid too much light from irradiating onto the photosensitive device 103, the red resin R' can be filled in the first opening K1. Since the light greater than 600 nm in the ambient light can penetrate the finger, the red light can be effectively transmitted through the red resin R', and the light in the near-infrared band greater than the wavelength of the red light is intercepted, so as to reduce the total amount of light received by the photosensitive device 103, and avoid the total amount of light exceeding the full well capacity of the photosensitive device 103 and failing to identify the fingerprint.

[0086] Generally, the black matrix 104 further includes a second opening K2 in which the color resist 106 is arranged. The emitted light of the light emitting device 102 transmits through the color resist 106 to realize the display function. Therefore, in the case that the first opening K1 is large, in order to balance the fingerprint identification effect and the display effect, the size of the first opening K1 needs to be reasonably set. Based on this, in some embodiments, the ratio K S of the width of the first opening K1 to the photoelectric conversion layer PIN of the corresponding photosensitive device 103 in the row direction X can be greater than or equal to 1 and less than 2, and the ratio K L of the length of the first opening K1 to the photoelectric conversion layer PIN of the corresponding photosensitive device 103 in the column direction Y can be greater than or equal to 1 and less than 2.

[0087] In some embodiments, in the above display substrate provided by the embodiments of the present disclosure, the red resin R' filling the first opening K1 can be the same layer and the same material as the red light color resist R, that is, the red resin R' and the red light color resist R are formed by patterning the same red resin material film layer, so as to reduce the number of film layers and save production cost.

[0088] In some embodiments, in the above display substrate provided by the embodiments of the present disclosure, as shown, Figures 4 to 6 each of the three adjacent photosensitive devices 103 in the same row is a first photosensitive device 31, a second photosensitive device 32 and a third photosensitive device 33, and the column where the first photosensitive device 31 is located is located between the column where the second photosensitive device 32 is located and the column where the second photosensitive device 32 is located in the adjacent two rows.

[0089] In the adjacent first photosensitive device 31, second photosensitive device 32 and third photosensitive device 33 in the same row:

[0090] The bottom electrode a of the first photosensitive device 31 is independent of the bottom electrode a of the second photosensitive device 32 and the bottom electrode a of the third photosensitive device 33, and the bottom electrode a of the second photosensitive device 32 is electrically connected to the bottom electrode a of the third photosensitive device 33.

[0091] The area of ​​the photoelectric conversion layer PIN contained in the photosensitive device 103 that is not blocked by the anode A of the light-emitting device 102 is the effective photosensitive area. The effective photosensitive area S1 of the first photosensitive device 31 is equal to the sum of the effective photosensitive area S2 of the second photosensitive device 32 and the effective photosensitive area S3 of the third photosensitive device 33.

[0092] The above-described arrangement of photosensitive devices 103 ensures that the photosensitive devices 103 are uniformly distributed in the gaps between the light-emitting devices 102, and makes the area of ​​the photoelectric conversion layer PIN in all detection pixels basically the same, thereby improving the uniformity of fingerprint imaging. It should be noted that in this disclosure, a detection pixel is either a second photosensitive device 32 and a third photosensitive device 33 electrically connected to the bottom electrode a, or a first photosensitive device 31 whose bottom electrode a is independent of the second photosensitive device 32 and the third photosensitive device 33.

[0093] In some embodiments, such as Figure 2 and Figure 3 As shown, each photosensitive device 103 is electrically connected to a readout transistor TFT2. To reduce the coupling capacitance between the photosensitive device 103 and the readout transistor TFT2, as follows... Figure 1 , Figures 4 to 6 As shown, the first photosensitive device 31 can be disposed at the gap between the blue light device (corresponding to blue color resist B) and the green light device (corresponding to green color resist G), the second photosensitive device 32 can be disposed at the gap between the green light device (corresponding to green color resist G) and the red light device (corresponding to red color resist R), and the third photosensitive device 33 can be disposed at the gap between the red light device (corresponding to red color resist R) and the blue light device (corresponding to blue color resist B). In this case, the orthographic projection of the first photosensitive device 31 on the substrate 101 is arranged in the same column as the orthographic projection of the red light device (corresponding to red color resist R), the orthographic projection of the second photosensitive device 32 on the substrate 101 is arranged in the same column as the orthographic projection of the blue light device (corresponding to blue color resist B), and the orthographic projection of the third photosensitive device 33 on the substrate 101 is arranged in the same column as the orthographic projection of the green light device (corresponding to green color resist G). In related technologies, in order to make the lifespans of red, green, and blue light devices approximately equal, the aperture ratio of blue light device B is usually set to > that of green light device > that of red light device. Therefore, in the column direction Y, there is a large space between the first photosensitive device 31 and the red light device to accommodate the readout transistor TFT2 electrically connected to the first photosensitive device 31. There is also a large space between the second photosensitive device 32 and the blue light device to accommodate the readout transistor TFT2 electrically connected to the bottom electrode a shared by the second photosensitive device 32 and the third photosensitive device 33.

[0094] Of course, in a specific implementation, the positions of the first photosensitive device 31, the second photosensitive device 32, and the third photosensitive device 33 can not be limited to the above-described arrangement. For example, in the case where the first photosensitive device 31, the second photosensitive device 32, and the third photosensitive device 33 are all small, the gap between any two light-emitting devices 102 is sufficient to arrange the photosensitive device 103 and the read transistor TFT2 electrically connected thereto, and in this case, the positions of the first photosensitive device 31, the second photosensitive device 32, and the third photosensitive device 33 can be arranged arbitrarily.

[0095] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, as shown in Figure 4 , the orthographic projection of the photoelectric conversion layer PIN of the photosensitive device 103 on the substrate 101 can overlap with the edge along the column direction Y extending from the orthographic projection of the anode A of the adjacent light-emitting device 102. Alternatively, as shown in Figure 5 , the orthographic projection of the photoelectric conversion layer PIN of the photosensitive device 103 on the substrate 101 can also not overlap with the orthographic projection of the anode A of the light-emitting device 102, which is not specifically limited herein.

[0096] In some embodiments, as shown in Figure 4 and Figure 5 , the orthographic projection of the photoelectric conversion layer PIN of the photosensitive device 103 on the substrate 101 can be a rectangle. In other embodiments, as shown in Figure 6 , the photoelectric conversion layer PIN of the first photosensitive device 31 can include a first photoelectric conversion layer (effective photosensitive area S 11 ) and a second photoelectric conversion layer (effective photosensitive area S 12 ) independent of each other, and the orthographic projections of the first photoelectric conversion layer, the second photoelectric conversion layer, the photoelectric conversion layer PIN of the second photosensitive device 32, and the photoelectric conversion layer PIN of the third photosensitive device 33 on the substrate 101 can all be squares or circles (as shown in Figure 12 ). Of course, in a specific implementation, the orthographic projection of the photoelectric conversion layer PIN on the substrate 101 can also be other shapes (for example, a regular polygon), which is not limited herein. Accordingly, in order to match the photoelectric conversion layer PIN, the first opening K1 can have the same shape as the photoelectric conversion layer PIN.

[0097] In addition, the present disclosure provides a fingerprint identification effect for the display substrate as shown in Figures 4 to 6 , as shown in Table 2. Wherein, the ratio represents the ratio of the amount of fingerprint feature signal to the total amount of light received by the photoelectric conversion layer PIN, and in Table 2, 144 μm 2 specifically represents the effective photosensitive area S 11 of the first photoelectric conversion layer or the effective photosensitive area S 12It can be seen from Table 2 that the PIN photoelectric conversion layer of the first photosensitive device 31 is divided into a first photoelectric conversion layer and a second photoelectric conversion layer with a smaller area, so that the collimation degree can be improved on the basis of meeting the effective photosensitive area requirement of fingerprint identification, the fingerprint ridge-valley illuminance difference is improved, and the fingerprint identification precision is higher.

[0098] Table 2

[0099]

[0100]

[0101] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, to realize the touch function, as shown in Figure 2 , Figure 3 and Figure 13 , the display substrate can further include a touch grid layer 107 located between the layer where the light emitting device 102 is located and the black matrix 104. The orthographic projection of the touch grid layer 107 on the substrate 101 is located within the orthographic projection of the black matrix 104, so as to prevent external light from being reflected out and affecting the display effect; and the orthographic projection of the touch grid layer 107 on the substrate 101 does not overlap with the orthographic projection of the PIN photoelectric conversion layer of the photosensitive device 103, so that when the light emitting device 102 is lit, the emitted light of the light emitting device 102 is prevented from being reflected to the photosensitive device 103 after being radiated upward to the touch grid layer 107, thereby affecting the fingerprint signal.

[0102] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, as shown in Figure 13 , the area where any grid of the touch grid layer 107 is located is provided with a PIN photoelectric conversion layer of a photosensitive device 103 or an effective light emitting layer of a light emitting device 102. At this time, the wiring of the touch grid is arranged on both sides of the PIN photoelectric conversion layer along the column direction Y. Optionally, in order to ensure that the resistance of the touch grid line in each direction is relatively uniform, the grid line width of the touch grid layer 107 extending along the column direction Y can be set to be half of the grid line width extending along other directions.

[0103] In some embodiments, in the display substrate provided in the embodiments of the present disclosure, as shown in Figure 14 and Figure 15 , the area where any grid of the touch grid layer 107 is located can be further provided with a PIN photoelectric conversion layer of a photosensitive device 103 and an effective light emitting layer of a light emitting device 102, which is equivalent to arranging the wiring of the touch grid on one side of the PIN photoelectric conversion layer along the column direction Y. At this time, the grid line width of the touch grid layer 107 extending in each direction is substantially equal, that is, the resistance of the touch grid line in each direction can be ensured to be relatively uniform.

[0104] The two configuration methods described above for the touch grid layer 107 can effectively utilize the area where the black matrix 104 is located, ensuring that the touch grid is evenly distributed within that area, resulting in high touch sensitivity without affecting fingerprint recognition and display performance. Of course, in practical implementations, if the requirement for touch accuracy is low, multiple photosensitive devices 103 and multiple light-emitting devices 102 can be simultaneously configured within any grid area of ​​the touch grid layer 107; this is not limited here.

[0105] In addition, this disclosure also addresses Figure 13 and Figure 14 The impact of two types of touch mesh layers 107 on fingerprint recognition performance was evaluated, and the results are shown in Table 3. Among them, as... Figure 9 As shown, D BM D represents the side length of the first opening K1. PIN Indicates the side length of the photoelectric conversion layer PIN, such as Figure 15 As shown, h represents the thickness of the black matrix 104, which is typically 1μm ≤ h ≤ 2μm. This thickness can be ignored. Therefore, h1 + h2 can approximate the distance H from the finger contact surface to the photosensitive device 103. As can be seen from Table 3, Figure 13 and Figure 14 Both methods of setting the touch grid layer 107 have minimal impact on fingerprint recognition, especially Figure 13 The method of setting touch grid lines on both sides of the photoelectric conversion layer PIN extending along the column direction Y, as shown, has almost no impact on the fingerprint recognition effect.

[0106] Table 3

[0107]

[0108] In some embodiments, in the display substrate provided in the present disclosure, such as Figure 15 As shown, it may also include an ultra-thin glass cover 108 located on the side of the black matrix 104 opposite to the substrate 101. Since the ultra-thin glass cover 108 retains the properties of glass while also having good flexibility, it can fully meet the requirements of foldable products.

[0109] Specifically, ultra-thin glass (UTG) refers to a glass layer with a thickness on the order of tens of micrometers or less, which is flexible, deformable, and foldable. In this invention, the thickness of the ultra-thin glass cover 108 is approximately 50 μm. Compared to polymer plastic films, the ultra-thin glass cover 108 can effectively prevent screen damage while providing better optical clarity; at the same time, the ultra-thin glass cover 108 is less prone to creases, has high reliability, and does not decompose naturally like plastic, resulting in a long lifespan, thus providing more stable and reliable protection for the display screen.

[0110] In some embodiments, in the display substrate provided by the embodiments of the present disclosure, as shown in Figure 15 The display substrate provided by the embodiments of the present disclosure can further include a driving transistor TFT1, a back film 109, a gate insulating layer 110, an interlayer dielectric layer 111, a first insulating layer 112, a resin layer 113, a support layer 114, an encapsulation layer 115, a buffer layer 116, a second planarization layer 117, a second planarization layer 118, a first adhesive layer 119, a second adhesive layer 120, and a transparent protective layer 121. Other essential components of the display substrate should be understood by those skilled in the art, and will not be described here again, nor should they be considered as a limitation on the present disclosure.

[0111] Based on the same inventive concept, the embodiments of the present disclosure provide a display device including the display substrate provided by the embodiments of the present disclosure. Since the display device solves the problem by a similar principle to the display substrate described above, the implementation of the display device provided by the embodiments of the present disclosure can refer to the implementation of the display substrate provided by the embodiments of the present disclosure, and the repeated parts will not be described again.

[0112] In some embodiments, the display device can be any product or component with display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, a smart watch, a fitness wristband, a personal digital assistant, etc. The display device includes but is not limited to the following components: a radio frequency unit, a network module, an audio output & input unit, a sensor, a display unit, a user input unit, an interface unit, a memory, a processor, a power supply, etc. In addition, those skilled in the art can understand that the above structure does not constitute a limitation on the display device provided by the embodiments of the present disclosure, in other words, the display device provided by the embodiments of the present disclosure can include more or less components described above, or combine some components, or arrange different components.

[0113] Based on the same inventive concept, the embodiments of the present disclosure further provide a fingerprint identification method, as shown in Figure 16 The method can include the following steps:

[0114] S1601, detecting the brightness of ambient light;

[0115] S1602, determining whether the brightness of ambient light is greater than a preset brightness, if yes, using the ambient light for fingerprint identification, if not, using the emission light of the light emitting device for fingerprint identification.

[0116] Specifically, in the case of using the emitted light of the light emitting device 102 for fingerprint identification, when the finger F contacts the transparent protective layer 121 of the display device, the light emitting device 102 is controlled to light up the surface light source to emit light, the light is emitted from the light emitting material layer of the light emitting device 102, and then upwardly passes through the film layers of the encapsulation layer 115, the color resistance 106, the ultra-thin glass cover plate 108, the transparent protective layer 121, etc. to reach the fingerprint interface, the light reflected and scattered back on the interface passes through the film layers of the transparent protective layer 121, the ultra-thin glass cover plate 108, the first opening K1, the encapsulation layer 115, the support layer 114, the pixel definition layer 105, etc. to reach the photosensitive device 103, is received by the photoelectric conversion layer PIN of the photosensitive device 103 and converted into an electrical signal, the signals reflected by the valleys and ridges are different, thereby performing fingerprint identification.

[0117] In the case of using ambient light for fingerprint identification, when the finger F contacts the transparent protective layer 121 of the display device, the external ambient light passes downward through the film layers of the transparent protective layer 121, the ultra-thin glass cover plate 108, the first opening K1, the encapsulation layer 115, the support layer 114, the pixel definition layer 105, etc. to reach the photosensitive device 103, is received by the photoelectric conversion layer PIN of the photosensitive device 103 and converted into an electrical signal, the signals reflected by the valleys and ridges are different, thereby performing fingerprint identification.

[0118] Although the preferred embodiments of the present disclosure have been described, those skilled in the art can make various modifications and variations to the embodiments of the present disclosure without departing from the spirit and scope of the embodiments of the present disclosure. Thus, if these modifications and variations of the embodiments of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure also intends to include these modifications and variations.

Claims

1. A display substrate, wherein, The application relates to a substrate, a plurality of light-emitting devices arranged in an array on the substrate, wherein the light-emitting devices comprise blue light devices, green light devices and red light devices, a plurality of light-sensitive devices between the layer of the light-emitting devices and the substrate, wherein the light-sensitive devices are arranged in an array on the substrate, and the orthographic projection of each light-sensitive device on the substrate and the orthographic projection of the gap between adjacent light-emitting devices overlap each other, a black matrix on the side of the layer of the light-emitting devices away from the substrate, wherein the orthographic projection of the black matrix on the substrate and the orthographic projection of the gap between adjacent light-emitting devices overlap each other, and the black matrix has a plurality of first openings, wherein the orthographic projection of the first openings on the substrate and the orthographic projection of the light-sensitive devices overlap each other, the total amount of light passing through the first openings and reaching the light-sensitive devices meets the signal-to-noise ratio of fingerprint identification and is less than the full well capacity of the light-sensitive devices, wherein every three adjacent light-sensitive devices in the same row are a first light-sensitive device, a second light-sensitive device and a third light-sensitive device, and the column of the first light-sensitive device is between the column of the second light-sensitive device and the column of the second light-sensitive device in adjacent two rows, wherein, in the first light-sensitive device, the second light-sensitive device and the third light-sensitive device in the same row, the bottom electrode of the first light-sensitive device is independent of the bottom electrode of the second light-sensitive device and the bottom electrode of the third light-sensitive device, the bottom electrode of the second light-sensitive device is electrically connected with the bottom electrode of the third light-sensitive device, the area of the photoelectric conversion layer of the light-sensitive device which is not shielded by the anode of the light-emitting device is the effective photosensitive area, the effective photosensitive area of the first light-sensitive device is equal to the sum of the effective photosensitive area of the second light-sensitive device and the effective photosensitive area of the third light-sensitive device, wherein, in the column direction, a light-sensitive device and a reading transistor electrically connected with the light-sensitive device are arranged between any two light-emitting devices, or a light-sensitive device is arranged between any two light-emitting devices, a reading transistor electrically connected with the first light-sensitive device is arranged between the first light-sensitive device and the red light device, and a reading transistor electrically connected with the second light-sensitive device and the third light-sensitive device sharing a bottom electrode is arranged between the second light-sensitive device and the blue light device. The first opening and the photoelectric conversion layer of the light-sensitive device are one-to-one corresponding and overlapping, and the center of the orthographic projection of the first opening on the substrate substantially coincides with the center of the orthographic projection of the photoelectric conversion layer of the corresponding light-sensitive device. The orthographic projection of the first opening on the substrate is located in the orthographic projection of the photoelectric conversion layer of the corresponding light-sensitive device. The optical comprehensive transmittance T of ambient light reaching the light-sensitive device through the finger and the first opening meets the following relationship: The light collection angle alpha determined by the first opening meets the following relationship: The first opening on the substrate is greater than or equal to the orthographic projection of the photoelectric conversion layer of the corresponding light-sensitive device. ​ ​ ​ ​ ​ 2.The display substrate of claim 1, wherein, ​ 3.The display substrate of claim 2, wherein, ​ 4.The display substrate of claim 3, wherein, ​ 0 < T < k*K s *K L ; wherein k is a coefficient, K S is a ratio of the width of the first opening to the width of the photoelectric conversion layer corresponding to the photosensitive device in the row direction, K L is a ratio of the length of the first opening to the length of the photoelectric conversion layer corresponding to the photosensitive device in the column direction. 5.The display substrate of claim 4, wherein, ​ a = arctan[P / (2hi)], 0 < (D LPIN + D LBM ) / (2*h2) < a; wherein P is a distance between two adjacent valley centers or two adjacent ridge centers of the fingerprint, h1 is a distance from a contact surface of the finger to the black matrix of the display substrate, h2 is a distance from the black matrix to the photosensitive device, D LPIN is a length of a photoelectric conversion layer of the photosensitive device in the column direction, D LBM is a length of the first opening in the column direction. 6.The display substrate of claim 5, wherein, 0 < k < 0.4, 0 < K S < 0.75, 0 < K L < 0.75, 8 μm ≤ D LPIN ≤ 40 μm, 50 μm ≤ hi ≤ 200 μm, 8 μm ≤ h2 ≤ 20 μm, 300 μm ≤ P ≤ 500 μm, 8 μm ≤ D SPIN ≤ 20 μm, D SPIN is the width of the photoelectric conversion layer of the light-sensitive device in the row direction. 7.The display substrate of claim 2, wherein, ​ ​ 8.The display substrate of claim 7, wherein, The ratio of the width of the first opening to the photoelectric conversion layer of the photosensitive device in the row direction is greater than or equal to 1 and less than 2, and the ratio of the length of the first opening to the photoelectric conversion layer of the photosensitive device in the column direction is greater than or equal to 1 and less than 2. 9.The display substrate of claim 7, wherein, Further comprising: A plurality of color resist located on the side of the black matrix away from the substrate, the color resist comprising a red light color resist, the red light color resist being in the same layer and same material as the red resin; The black matrix further comprises a plurality of second openings, the color resist is located at the second opening, and the orthographic projection of the color resist on the substrate and the orthographic projection of the light emitting device overlap each other. 10.The display substrate of claim 1, wherein, The orthographic projection of the photoelectric conversion layer of the photosensitive device on the substrate and the edge of the anode of the light emitting device extending in the column direction overlap each other. 11.The display substrate of claim 1, wherein, The orthographic projection of the photoelectric conversion layer of the photosensitive device on the substrate and the orthographic projection of the anode of the light emitting device do not overlap each other. 12.The display substrate of claim 10 or 11, wherein, The orthographic projection of the photoelectric conversion layer of the photosensitive device on the substrate is a rectangle. 13.The display substrate of claim 1, wherein, The photoelectric conversion layer of the first photosensitive device comprises a first photoelectric conversion layer and a second photoelectric conversion layer which are independent of each other. 14.The display substrate of claim 13, wherein, The orthographic projection of the first photoelectric conversion layer, the second photoelectric conversion layer, the photoelectric conversion layer of the second photosensitive device, and the photoelectric conversion layer of the third photosensitive device on the substrate are all squares or circles. 15.The display substrate of claim 1, wherein, Further comprising a touch grid layer between the layer of the light emitting device and the black matrix, the orthographic projection of the touch grid layer on the substrate is located within the orthographic projection of the black matrix, and the orthographic projection of the touch grid layer on the substrate and the orthographic projection of the photoelectric conversion layer contained in the photosensitive device do not overlap each other. 16.The display substrate of claim 15, wherein, Any grid area of the touch grid layer is provided with a photoelectric conversion layer of the photosensitive device or an effective light emitting layer of the light emitting device.

17. The display substrate of claim 16, wherein, The grid line width of the touch grid layer extending in the column direction is half of the grid line width extending in other directions.

18. The display substrate of claim 15, wherein, Any grid area of the touch grid layer is provided with a photoelectric conversion layer of the photosensitive device and an effective light emitting layer of the light emitting device.

19. The display substrate of claim 18, wherein, The grid line width of the touch grid layer extending in each direction is approximately equal.

20. The display substrate of claim 19, wherein, Further comprising an ultra-thin glass cover plate located on the side of the black matrix away from the substrate.

21. A display device, wherein, The display substrate comprises any one of claims 1-20.

22. A method of fingerprinting, wherein, Applied to the display substrate of any one of claims 1-20, comprising: Detecting the brightness of the ambient light; Judging whether the brightness of the ambient light is greater than a preset brightness, if yes, using the ambient light for fingerprint identification, if not, using the emitted light of the light emitting device for fingerprint identification.

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