Fingerprint recognition substrate and display device having the same

Abstract

The application relates to a fingerprint identification substrate and a display device with the same, the fingerprint identification substrate comprising: a substrate, a plurality of photoelectric conversion elements on the substrate, a metal diaphragm layer, a collimating optical structure on the light-incident side of each photoelectric conversion element, a microlens layer and a glass cover plate, which are sequentially stacked along a first direction; the metal diaphragm layer comprises a plurality of first light transmission holes; the collimating optical structure comprises a plurality of light shielding groups which are sequentially stacked; each light shielding group comprises a light transmission layer and a light shielding layer which are sequentially stacked along the first direction; each light shielding layer comprises a plurality of second light transmission holes; along a direction gradually away from the substrate, the diameters of the second light transmission holes of the plurality of light shielding groups gradually increase layer by layer; and the diameter of the first light transmission hole is smaller than that of the adjacent second light transmission hole. According to the fingerprint identification substrate, the diameter of the hole can be smaller due to the metal material, the diameter of the first light transmission hole on the metal diaphragm layer is smaller than that of the second light transmission hole, and the crosstalk of light can be better prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of under-screen optical fingerprint identification, and in particular to a fingerprint identification substrate and a display device with the same. BACKGROUND

[0002] With the development of the manufacturing technology of full screens, as the screen ratio increases, an optical fingerprint identification module usually includes a fingerprint identification sensor array and a back plate thereof, and an optical structure layer arranged above the fingerprint identification sensor array. In order to prevent adjacent sensors from receiving fingerprint information from a far position and causing the information received by the sensors to be confused, a layer of optical structure is arranged on the fingerprint identification sensor array to remove stray light and achieve fingerprint identification. However, the existing technical solutions only prevent crosstalk of light at a large angle by forming a plurality of BM layers, and the effect is not good, and there are problems such as unclear fingerprint images of thin fingers of female under strong light at an outdoor angle of 45 degrees. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides a fingerprint identification substrate capable of improving collimation effect, preventing crosstalk of light, and improving the clarity of fingerprint images of thin fingers obtained under strong light.

[0004] The fingerprint identification substrate according to the present application comprises: a substrate substrate, a plurality of photoelectric conversion elements located on the substrate substrate, a metal diaphragm layer, a collimating optical structure located on the light-in side of each photoelectric conversion element, a microlens layer, and a glass cover plate, which are sequentially stacked in a first direction, the photoelectric conversion elements are used to collect light reflected by fingerprints, the metal diaphragm layer comprises a plurality of first light transmission holes, the collimating optical structure comprises a plurality of light shielding groups which are sequentially stacked, each light shielding group comprises a light transmission layer and a light shielding layer which are sequentially stacked in the first direction, each light shielding layer comprises a plurality of second light transmission holes, the diameters of the second light transmission holes of the plurality of light shielding groups gradually increase in the direction away from the substrate substrate, the diameter of the first light transmission hole is smaller than the diameter of the adjacent second light transmission hole, the microlens layer comprises a plurality of microlens groups, the microlens groups are projected in the plane where the substrate substrate is located, the microlens groups, the second light transmission holes, the first light transmission holes, and the photoelectric conversion elements correspond one-to-one, the orthographic projections of the corresponding microlens groups, the second light transmission holes, and the first light transmission holes at least partially overlap, and the overlapping area at least partially overlaps with the orthographic projection of the photoelectric conversion elements.

[0005] According to the fingerprint identification substrate of the present application, by arranging the metal diaphragm layer, the diameter of the hole can be smaller due to the metal material, the diameter of the first light transmission hole on the metal diaphragm layer is smaller than the diameter of the second light transmission hole, which can better converge the light, prevent crosstalk of light, and improve the clarity of the fingerprint images of thin fingers obtained under strong light.

[0006] According to the fingerprint identification substrate of the present application, the collimating optical structure comprises a functional area and a transition area adjacent to the functional area, and the functional area covers the corresponding micro-lens group and the corresponding photoelectric conversion element in the planar projection of the substrate.

[0007] Optionally, the collimating optical structure comprises a first light shielding group and a second light shielding group, the first light shielding group is adjacent to the metal diaphragm layer, and the length of the transition area is greater than or equal to 1700 μm.

[0008] Optionally, the length difference between the first light shielding group and the second light shielding group is in the range of 1.5-5 μm.

[0009] Optionally, the two ends of the light shielding layer and the light transmission layer of the first light shielding group are flush in the length direction, and the two ends of the light shielding layer and the light transmission layer of the second light shielding group are flush in the length direction.

[0010] Optionally, the length difference between the light transmission layer and the light shielding layer of the first light shielding group is in the range of 1.5-5 μm, and the length difference between the light transmission layer and the light shielding layer of the second light shielding group is in the range of 1.5-5 μm.

[0011] According to the fingerprint identification substrate of the present application, an infrared filter layer is arranged between the metal diaphragm layer and the collimating optical structure, and the thickness of the infrared filter layer is in the range of 2.4-3 μm.

[0012] According to the fingerprint identification substrate of the present application, the micro-lens group comprises an even number of micro-lenses, and the micro-lenses are formed in an inverted trapezoidal structure.

[0013] Optionally, the planar projection of the micro-lens in the substrate is circular or square, and the four corners of the micro-lens are smoothly transitioned.

[0014] According to the display device of the present application, the above-mentioned fingerprint identification substrate is arranged.

[0015] According to the display device of the present application, the diameter of the first light transmission hole on the metal diaphragm layer is smaller than that of the second light transmission hole, which can better converge light and prevent light crosstalk, thereby improving the clarity of the fingerprint image of a thin finger obtained by the display device under strong light. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional view of a fingerprint recognition substrate according to an embodiment of the present invention;

[0019] Figure 2 A cross-sectional view of the microlens of the fingerprint recognition substrate according to an embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of a microlens assembly of a fingerprint recognition substrate according to an embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the microlens assembly of a fingerprint recognition substrate according to another embodiment of the present invention;

[0022] Figure 5 This is a side view of the collimating optical structure of a fingerprint recognition substrate according to Embodiment 1 of the present invention;

[0023] Figure 6 for Figure 5 Microscopic metallographic image of a collimated optical structure;

[0024] Figure 7 This is a side view of the collimating optical structure of the fingerprint recognition substrate according to Embodiment 2 of the present invention;

[0025] Figure 8 for Figure 7 Microscopic metallographic image of a collimated optical structure;

[0026] Figure 9 This is a side view of the collimating optical structure of the fingerprint recognition substrate according to Embodiment 3 of the present invention;

[0027] Figure 10 for Figure 9 Microscopic metallographic image of a collimated optical structure;

[0028] Figure 11 This is a microstructure image of the light-transmitting layer of the first light-shielding group in the transition region of the collimating optical structure of the fingerprint recognition substrate according to an embodiment of the present invention.

[0029] Figure 12A length and film thickness relationship curve of a light shielding layer of a first light shielding group of a transition area of a collimating optical structure of a fingerprint identification substrate according to an embodiment of the present application;

[0030] Figure 13 A length and film thickness relationship curve of a light shielding layer of a second light shielding group of a transition area of a collimating optical structure of a fingerprint identification substrate according to an embodiment of the present application;

[0031] Figure 14 A length and film thickness relationship curve of a light shielding layer of a second light shielding group of a transition area of a collimating optical structure of a fingerprint identification substrate according to an embodiment of the present application;

[0032] Figure 15 A length and film thickness relationship curve of a light shielding layer between a second light shielding group and a microlens layer of a transition area of a collimating optical structure of a fingerprint identification substrate according to an embodiment of the present application;

[0033] Figure 16 A curve of filtering capability of different thicknesses of an infrared filter layer of a fingerprint identification substrate according to an embodiment of the present application.

[0034] Reference signs:

[0035] A fingerprint identification substrate 1, a substrate substrate 10, a photoelectric conversion element 20, a metal diaphragm layer 30, a first light transmission hole 31, a collimating optical structure 40, a first light shielding group 41a, a second light shielding group 41b, a light transmission layer 412, a light shielding layer 414, a second light transmission hole 4142, a microlens layer 50, a microlens group 51, a microlens 512, an infrared filter layer 60, a functional area A, a transition area B, DETAILED DESCRIPTION

[0036] To make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0037] As shown in Figure 1 A fingerprint identification substrate 1 according to an embodiment of the present application comprises, in sequence along a first direction, a substrate substrate 10, a plurality of photoelectric conversion elements 20 located on the substrate substrate 10, a metal diaphragm layer 30, a collimating optical structure 40 located on an incident light side of each photoelectric conversion element 20, a microlens layer 50, and a glass cover plate.

[0038] Specifically, the photoelectric conversion element 20 is used to collect the light reflected by the fingerprint. According to the principle of total reflection of light, the light is reflected by the photoelectric conversion element 20 after being reflected by the surface of the glass cover plate pressed by the fingerprint. The amount of reflected light depends on the depth of the ridges and valleys of the fingerprint pressed on the surface of the glass cover plate, and the oil and moisture between the skin and the glass. The light that passes through the glass cover plate and reaches the valleys is totally reflected at the air interface of the light transmission layer 412, and the light is reflected to the photoelectric conversion element 20. The light that reaches the ridges is not totally reflected, but is absorbed by the contact surface of the ridges and the glass cover plate or diffusely reflected to other places, so that the image of the fingerprint is formed on the photoelectric conversion element 20.

[0039] The photoelectric conversion element 20 includes a P-type semiconductor layer, an intrinsic semiconductor layer, and an N-type semiconductor layer which are stacked.

[0040] The metal diaphragm layer 30 includes a plurality of first light transmission holes 31. The collimating optical structure 40 includes a plurality of light shielding groups which are stacked in sequence. Each light shielding group includes a light transmission layer 412 and a light shielding layer 414 which are stacked in sequence along the first direction. Each light shielding layer 414 includes a plurality of second light transmission holes 4142. The diameters of the second light transmission holes 4142 of the plurality of light shielding groups gradually increase layer by layer in a direction away from the substrate 10. The diameter of the first light transmission hole 31 is smaller than the diameter of the adjacent second light transmission hole 4142. The microlens layer 50 includes a plurality of microlens groups 51 which are projected in the plane of the substrate 10. The microlens group 51, the second light transmission hole 4142, the first light transmission hole 31, and the photoelectric conversion element 20 correspond one-to-one. The orthographic projection of the corresponding microlens group 51, the second light transmission hole 4142, and the first light transmission hole 31 at least partially overlaps, and the overlapping area at least partially overlaps with the orthographic projection of the photoelectric conversion element 20.

[0041] In some embodiments, in order to improve the collimating effect of the collimating optical structure 40 on the light reflected by the fingerprint, the axis of the first light transmission hole 31 and the corresponding mutually overlapping second light transmission hole 4142 coincide, that is, the orthographic projection centers of the mutually overlapping second light transmission hole 4142 and the corresponding first light transmission hole 31 on the substrate 10 are the same. Of course, considering the process and other factors, the orthographic projection centers of the mutually overlapping second light transmission hole 4142 and the corresponding first light transmission hole 31 are allowed to be slightly offset in the actual product. The axis here is along the first direction.

[0042] "In the direction gradually away from the substrate 10, the diameters of the second light-transmitting holes 4142 of multiple light-shielding groups increase layer by layer". For example, the collimating optical structure 40 includes a first light-shielding group 41a, a second light-shielding group 41b, a third light-shielding group... an Nth light-shielding group stacked in sequence along the first direction. Define the diameter of the first light-transmitting hole 31 of the metal diaphragm layer 30 as W0, the diameter of the second light-transmitting hole 4142 on the light-shielding layer 414 of the first light-shielding group 41a as W1, the diameter of the second light-transmitting hole 4142 on the light-shielding layer 414 of the second light-shielding group 41b as W2, the diameter of the second light-transmitting hole 4142 on the light-shielding layer 414 of the third light-shielding group as W3, and the diameter of the second light-transmitting hole 4142 on the light-shielding layer 414 of the Nth light-shielding group as WN. W0, W1, W2, W3... WN satisfy: W0 < W1 < W2 < W3 <... < WN.

[0043] The diameters of the second light-transmitting holes 4142 in the same layer are the same. For example, the diameters of multiple second light-transmitting holes 4142 on the light-shielding layer 414 of the first light-shielding group 41a are equal, and the diameters of multiple second light-transmitting holes 4142 on the light-shielding layer 414 of the second light-shielding group 41b are equal.

[0044] In some embodiments, as Figure 1 shown, the collimating optical structure 40 includes a first light-shielding group 41a and a second light-shielding group 41b. The first light-shielding group 41a is adjacent to the metal diaphragm layer 30, and the second light-shielding group 41b is located on the side of the first light-shielding group 41a away from the metal diaphragm layer 30. Define the diameter of the first light-transmitting hole 31 of the metal diaphragm layer 30 as W0, the diameter of the second light-transmitting hole 4142 on the light-shielding layer 414 of the first light-shielding group 41a as W1, and the diameter of the second light-transmitting hole 4142 on the light-shielding layer 414 of the second light-shielding group 41b as W2. W0, W1, W2 satisfy: W0 < W1 < W2. 2 < W0 < 4μm, 10 < W1 < 12μm, 20 < W2 < 22μm. The thickness H of the microlens is 8 - 10μm. In this way, while ensuring the ability of the fingerprint recognition substrate 1 to prevent optical crosstalk, it can prevent the fingerprint recognition substrate 1 from being too thick, making the overall fingerprint recognition substrate 1 thin and light. Among them, W0 can be 2.5μm, 3μm, 3.5μm, etc., W1 can be 10.5μm, 11μm, 11.5μm, etc., W2 can be 20.5μm, 21μm, 21.5μm, etc., and H can be 8μm, 8.5μm, 9μm, 9.5μm, 10μm.

[0045] For the fingerprint recognition substrate 1 according to the embodiment of the present invention, the microlens group 51 includes an even number of microlenses 512. Preferably, as Figure 3 and Figure 4 shown, the microlens group 51 includes four microlenses 512, and the four microlenses 512 correspond to one photoelectric conversion element 20. AsFigure 2 As shown, the bottom wall of the microlens 512 is parallel to the substrate 10, and the angle between the side wall and the bottom wall of the microlens 512 is a, which satisfies: 90° < a < 170°. Wherein, a can be 100°, 110°, 120°, 130°, 140°, 150°, 160° and 170°.

[0046] In some embodiments, the projection in the plane where the substrate 10 is located is as shown in FIG. 6A, and the projection in the plane where the substrate 10 is located is as shown in FIG. 6B. Figure 3 As shown, the orthographic projection shape of the microlens 512 is a circle; or as shown in FIG. 6C, the orthographic projection shape of the microlens 512 is a square, and the four corners of the microlens 512 are smoothly transitioned. Figure 4 As shown, the orthographic projection shape of the microlens 512 is a circle; or as shown in FIG. 6C, the orthographic projection shape of the microlens 512 is a square, and the four corners of the microlens 512 are smoothly transitioned.

[0047] According to the fingerprint identification substrate 1 of the embodiment of the present application, by arranging the metal diaphragm layer 30, due to the metal material, the diameter of the hole can be smaller, the diameter of the first light transmission hole 31 on the metal diaphragm layer 30 is smaller than the diameter of the second light transmission hole 4142, which can better converge the light and prevent light crosstalk, and improve the clarity of the fingerprint image of the thin finger obtained under strong light.

[0048] Table 1 is the ability difference data of preventing light crosstalk of the technical scheme of the present application and the existing technical scheme, wherein FWHM is the full name of Full Width at Half Maxima, and the Chinese name is half peak full width. As can be seen from Table 1, when the angle between the light beam and the substrate 10 is 45°, the crosstalk rate of the existing technical scheme is 4%, and the crosstalk rate of the present application is 0%. It can be seen that the anti-crosstalk effect of the present application is better, the integral area of the existing technology for preventing light beam crosstalk is 3.61, and the integral area of the present application for preventing light beam crosstalk reaches 5.42, which is 50% higher than the microlens next to the comparative example. It can be seen that the integral area of the present application for preventing light beam crosstalk is larger, and the effect of preventing crosstalk is better.

[0049] Table 1 is the ability difference data of preventing light crosstalk of the technical scheme of the present application and the existing technical scheme

[0050]

[0051] As shown in FIG. 1A, FIG. 1B, Figure 5 Figure 7 , and Figure 9 As shown in FIG. 1A, FIG. 1B,​

[0052] Example 1:

[0053] like Figure 5 As shown, when projected onto the plane of the substrate 10, the orthographic projection of functional region A covers the orthographic projection of the corresponding microlens group 51 and the orthographic projection of the corresponding photoelectric conversion element 20. The cross-section of each light-shielding group in transition region B is a right-angled trapezoidal structure. Each layer of transition region B includes right-angled ends and non-right-angled ends located at both ends along the length direction. The right-angled ends of each layer of transition region B are adjacent to and flush with each corresponding layer of functional region A. That is to say, each layer in functional region A and transition region B of collimating optical structure 40 shares the same layer. In the molding process, each corresponding layer of functional region A and transition region B is integrally molded. The reason for distinguishing between transition region B and functional region A is to ensure that the film thickness of each layer of functional region A, which is directly opposite to photoelectric conversion element 20, is stable.

[0054] In some embodiments, the light-shielding layer 414 comprises BM (Black Matrix) resin, and the light-transmitting layer 412 comprises OC (Overcoat). The reason for setting the transition zone B is that the light-shielding layer 414 and the light-transmitting layer 412 in the collimating optical structure 40 are prepared layer by layer. Since the thickness of the light-transmitting layer 412 is relatively thick, under the influence of large step differences, the thickness of each layer in the collimating optical structure 40 has a "climbing" process from the edge to the direction close to the functional area A. After a certain distance, the thickness of each layer can reach stability. This is a problem that will exist in the actual production process. Since the degree of optical path crosstalk and imaging effect are very sensitive to the thickness of the light-shielding layer 414 and the thickness of the light-transmitting layer 412, it is necessary to set the transition zone B to ensure that the thickness of each layer in the functional area A is stable and controllable.

[0055] Wherein, "cross section" refers to the cross section passing through the central axis of the microlens 512 in a direction perpendicular to the substrate 10, and "length direction" refers to the direction perpendicular to the first direction in the cross section.

[0056] In other words, the stacked structure of the fingerprint recognition substrate 1 in the transition region B of the collimating optical structure 40 is a substrate 10, a photoelectric conversion element 20, a metal aperture layer 30, the transition region B, a filling layer and a glass cover plate stacked sequentially along the first direction.

[0057] Example 2:

[0058] Projecting onto the plane where the substrate 10 is located, the orthographic projection of functional area A covers the orthographic projection of the corresponding microlens group 51 and the orthographic projection of the corresponding photoelectric conversion element 20, and the non-right-angle ends of the cross-section of each light-shielding group in transition area B are flush.

[0059] Example 3:

[0060] In the plane in which the substrate 10 lies, the orthographic projection of the functional area A covers the orthographic projection of the corresponding microlens group 51 and the orthographic projection of the corresponding photoelectric conversion element 20, and the wrapping of the light-blocking group in the transition area B away from the photoelectric conversion element 20 is close to the light-blocking group of the photoelectric conversion element 20.

[0061] Since the film thickness of the light-transmitting layer 412 is large, when the light-blocking layer 414 is prepared, it is easy to leave some raw material for preparing the light-blocking layer 414 on the edge of the light-transmitting layer 412, which will affect the light-transmitting property of the light-transmitting layer 412. Therefore, along the first direction, the non-right-angle ends of the multiple light-blocking groups in the transition area B are arranged in a positive step-by-step manner. In this way, the possibility of leaving the raw material of the light-blocking layer 414 on the light-transmitting layer 412 can be greatly reduced. As shown in Figure 8 In the structure shown in Example 2, the length of the light-blocking layer raw material left on the light-transmitting layer 412 reaches 9.8 μm, Figure 9 In the structure shown in Example 3, the length of the light-blocking layer raw material left on the light-transmitting layer 412 reaches 23 μm, as shown in Figure 6 In the structure shown in Example 1, the length of the light-blocking layer raw material left on the light-transmitting layer 412 can be reduced to 6.2 μm. Therefore, the structure of Example 1 is preferred.

[0062] In some embodiments, the collimating optical structure 40 includes a first light-blocking group 41a and a second light-blocking group 41b, and the collimating optical structure 40 further includes a light-transmitting layer 412 arranged between the second light-blocking group 41b and the microlens layer 50, so as to separate the light-blocking layer 414 of the second light-blocking group 41b from the microlens layer 50, the first light-blocking group 41a is adjacent to the metal diaphragm layer 30, and the length L of the transition area B is greater than or equal to 1700 μm.

[0063] In some embodiments, as shown in Figure 11 the length of the light-transmitting layer 412 of the first light-blocking group 41a gradually stabilizes from the edge to the functional area A is at least 20 μm; as shown in Figure 12 the length of the light-blocking layer 414 of the first light-blocking group 41a gradually increases from the edge to a stable length is at least 800 μm; as shown in Figure 13 the length of the light-transmitting layer 412 of the second light-blocking group 41b gradually increases from the edge to a stable length is at least 1200 μm; as shown in Figure 14 the length of the light-blocking layer 414 of the second light-blocking group 41b gradually increases from the edge to a stable length is at least 1400 μm, as shown in Figure 15As shown, the film thickness of the light-transmitting layer 412 between the second light-shielding group 41b and the microlens layer 50 gradually increases from the edge to a stable length of at least 1700 μm, so the length of the transition zone B is greater than or equal to 1700 μm, which can ensure that the film thickness of the light-transmitting layer 412 and the light-shielding layer 414 of the first light-shielding group 41a and the light-transmitting layer 412 and the light-shielding layer 414 of the second light-shielding group 41b are stable and reliable.

[0064] In some embodiments, the length difference M between the first light-shielding group 41a and the second light-shielding group 41b ranges from 1.5 μm to 5 μm. M can be 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc.

[0065] In some embodiments, the two ends of the light-shielding layer 414 and the light-transmitting layer 412 of the first light-shielding group 41a in the length direction are flush, and the two ends of the light-shielding layer 414 and the light-transmitting layer 412 of the second light-shielding group 41b in the length direction are flush.

[0066] In some embodiments, the length difference M1 between the light-transmitting layer 412 and the light-shielding layer 414 of the first light-shielding group 41a ranges from 1.5 μm to 5 μm, where M1 can be 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc.

[0067] The length difference M2 between the light-transmitting layer 412 and the light-shielding layer 414 of the second light-shielding group 41b ranges from 1.5 μm to 5 μm. M2 can be 1.5 μm, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, etc.

[0068] According to the fingerprint identification substrate 1 of the embodiment of the present application, as shown in Figure 1 As shown, the infrared filter layer 60 is arranged between the metal diaphragm layer 30 and the collimating optical structure 40, so that the ambient light above 600 nm can be filtered through the infrared filter layer 60, preventing the ambient light from entering the photoelectric conversion element 20 through the relatively thin fingers of women or children, etc., to generate identification interference, and improving the clarity of the fingerprint signal.

[0069] As shown in Figure 16As shown, the thickness of the infrared filter layer 60 ranges from 2.4 to 3 μm. The thicker the thickness of the infrared filter layer 60, the better the filtering effect on the ambient light, but the thickness of the fingerprint identification substrate 1 will also increase with the increase of the thickness of the infrared filter layer 60, therefore, the thickness of the infrared filter layer 60 should be selected appropriately. In some embodiments, preferably, the thickness of the infrared filter layer 60 is 2.71 μm, and it has been verified through experiments that the error rate of the infrared filter layer 60 with a thickness of 2.71 μm remains within 3% under strong light conditions, the cutoff rate of the light beam of 600 nm reaches more than 88%, and the cutoff rate of the light beam of 620 nm reaches more than 1%.

[0070] The display device according to the embodiments of the present application comprises the fingerprint identification substrate 1 described above.

[0071] The display device according to the embodiments of the present application, by arranging the metal diaphragm layer 30, due to the metal material, the diameter of the opening can be smaller, the diameter of the first light transmission hole 31 on the metal diaphragm layer 30 is smaller than that of the second light transmission hole 4142, which can better converge the light and prevent light crosstalk, and improve the clarity of the fingerprint image of the thin finger obtained by the display device under strong light.

[0072] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0073] In the description of the present application, it should be noted that unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between the two elements inside. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0074] In the description of the specification, reference to "one embodiment", "some embodiments", "an exemplary embodiment", "an example", "a specific example", or "some examples" means that a particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "in some embodiments", "in an exemplary embodiment", "an example", "a specific example", or "some examples" in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics being described can be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A fingerprint recognition substrate, characterized in that, include: The substrate, a plurality of photoelectric conversion elements on the substrate, a metal aperture layer, a collimating optical structure on the light-incident side of each photoelectric conversion element, a microlens layer, and a glass cover plate are stacked sequentially along a first direction. The photoelectric conversion element is used to collect the light reflected from the fingerprint. The metal aperture layer includes a plurality of first light-transmitting holes. The collimating optical structure includes sequentially stacked light-shielding groups. Each light-shielding group includes a light-transmitting layer and a light-shielding layer sequentially stacked along the first direction. Each light-shielding layer includes multiple second light-transmitting holes. Along the direction gradually moving away from the substrate, the diameter of the second light-transmitting holes in the multiple groups of light-shielding groups increases layer by layer. The diameter of the first light-transmitting hole is smaller than the diameter of the adjacent second light-transmitting hole. The microlens layer includes multiple microlens groups that project onto the plane of the substrate. Each microlens group, the second light-transmitting aperture, the first light-transmitting aperture, and the photoelectric conversion element correspond one-to-one. The orthographic projections of corresponding microlens groups, the second light-transmitting aperture, and the first light-transmitting aperture at least partially overlap, and the overlapping area at least partially overlaps with the orthographic projection of the photoelectric conversion element. The collimating optical structure includes a functional area and a transition area adjacent to the functional area. In a direction perpendicular to the plane of the substrate, the orthographic projection of the functional area covers the orthographic projection of the corresponding microlens group and the orthographic projection of the corresponding photoelectric conversion element. The cross-section of each group of light-shielding groups in the transition area is a right-angled trapezoidal structure. Each layer of the transition area includes right-angled ends and non-right-angled ends located at both ends along the length direction. The right-angled ends of each layer of the transition area are adjacent to and flush with the corresponding layer of the functional area. Along the first direction, the non-right-angled ends of multiple groups of light-shielding groups in the transition area are arranged in a stepped pattern. The collimating optical structure includes a first light-shielding group and a second light-shielding group, the first light-shielding group being adjacent to the metal aperture layer, and the length of the transition region being greater than or equal to 1700 μm.

2. The fingerprint recognition substrate according to claim 1, characterized in that, The length difference between the first shading group and the second shading group ranges from 1.5 to 5 μm.

3. The fingerprint recognition substrate according to claim 1, characterized in that, The two ends of the light-shielding layer and the light-transmitting layer in the first light-shielding group are aligned along their length, and the two ends of the light-shielding layer and the light-transmitting layer in the second light-shielding group are aligned along their length.

4. The fingerprint recognition substrate according to claim 3, characterized in that, The length difference between the light-transmitting layer and the light-shielding layer of the first light-shielding group is in the range of 1.5 to 5 μm, and the length difference between the light-transmitting layer and the light-shielding layer of the second light-shielding group is in the range of 1.5 to 5 μm.

5. The fingerprint recognition substrate according to claim 1, characterized in that, An infrared filter layer is provided between the metal aperture layer and the collimating optical structure, and the thickness of the infrared filter layer ranges from 2.4 to 3 μm.

6. The fingerprint recognition substrate according to claim 1, characterized in that, The microlens group includes an even number of microlenses, the bottom wall of each microlens is parallel to the substrate, and the angle between the sidewall and the bottom wall of each microlens is α, where α satisfies: 90° < α < 170°.

7. The fingerprint recognition substrate according to claim 6, characterized in that, When projected onto the plane of the substrate, the orthographic projection shape of the microlens is circular. Alternatively, the orthographic projection shape of the microlens may be square, with the four corners of the microlens rounded off smoothly.

8. A display device, characterized in that, Includes the fingerprint recognition substrate as described in any one of claims 1-7.

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