Fingerprint recognition device and forming method thereof

Abstract

A fingerprint recognition device and its formation method include: a photosensitive layer having a horizontal pixel region on its surface; an aperture layer located on the photosensitive layer and having multiple apertures; and a convex lens group located on the aperture layer and projecting onto the photosensitive layer within the pixel region. The convex lens group includes multiple convex lenses, each corresponding to the aperture. The center of the bottom surface of each convex lens and the center of the corresponding aperture form a sub-field of view central axis. The projections of any two sub-field of view central axes belonging to the same pixel region intersect in at least one vertical plane, and the intersection point is located above the convex lens group. The fingerprint recognition device can improve image resolution and enhance fingerprint imaging clarity. It also helps reduce the risk of optical crosstalk, further improving imaging quality.

Description

Technical Field

[0001] The present invention relates to the field of fingerprint recognition technology, and in particular to a fingerprint recognition device and a forming method thereof. Background Art

[0002] Fingerprint recognition devices can realize automatic fingerprint collection and are widely used in devices such as attendance machines, access control systems, mobile phones or tablets.

[0003] According to the fingerprint imaging principle, fingerprint recognition devices can be divided into optical fingerprint recognition devices, semiconductor capacitance recognition devices, semiconductor thermal recognition devices, semiconductor pressure-sensitive recognition devices, etc.

[0004] Among them, the optical fingerprint recognition device mainly uses the principle of refraction and reflection of light. The light emitted by the light source is refracted at different angles on the uneven lines of the fingerprint on the surface of the finger, and the reflected light is different in brightness. The optical sensor will correspondingly collect image information of different brightness levels, thereby completing the fingerprint collection.

[0005] Optical fingerprint recognition devices have strong environmental adaptability and good stability, and low production costs, so optical fingerprint recognition devices are widely used.

[0006] However, the structure of existing optical fingerprint recognition devices still needs to be improved. Summary of the Invention

[0007] The problem solved by the present invention is to provide a fingerprint identification device and a forming method thereof, which are helpful to improve the quality of fingerprint imaging.

[0008] To solve the above problems, the present invention provides a fingerprint recognition device, comprising: a photosensitive layer, wherein the surface of the photosensitive layer has a horizontal pixel area; an aperture layer, located on the photosensitive layer, and the aperture layer has multiple aperture holes; a convex lens group, located on the aperture layer and whose projection toward the photosensitive layer is located within the pixel area, the convex lens group including multiple convex lenses, the convex lenses corresponding to the aperture holes, the center of the bottom surface of the convex lens and the corresponding center of the aperture hole forming a sub-field of view center axis, and any two sub-field of view center axes belonging to the same pixel area intersect in at least one vertical plane projection, and the intersection point is located above the convex lens group.

[0009] Optionally, the convex lens and the corresponding aperture hole constitute a focusing collimating unit, and the sub-fields of view of any two focusing collimating units belonging to the same pixel area overlap, and the boundary of the sub-field of view of the focusing collimating unit coincides with the path of the incident light with the maximum inclination angle that can pass through the aperture hole, and the inclination angle is the angle between the incident light and the central axis of the sub-field of view.

[0010] Optionally, the fingerprint recognition device further includes: a display panel, wherein the display panel is located above the convex lens group.

[0011] Optionally, on the top surface of the display panel, a ratio of an overlapping area of ​​sub-fields of view of any two focusing and collimating units belonging to the same pixel area to an area of ​​a sub-field of view of a single focusing and collimating unit is equal to or greater than 50%.

[0012] Optionally, on the top surface of the display panel, a ratio of an overlapping area of ​​sub-fields of view of any two focusing and collimating units belonging to the same pixel area to an area of ​​a sub-field of view of a single focusing and collimating unit is equal to or greater than 90%.

[0013] Optionally, the central axes of all the sub-fields of view belonging to the same pixel area intersect at the same point.

[0014] Optionally, there is an air gap between the display panel and the convex lens group.

[0015] Optionally, the air gap has a thickness of 0.1 mm to 0.6 mm.

[0016] Optionally, the display panel includes: a panel body; and a protective glass, wherein the protective glass covers the top surface of the panel body.

[0017] Optionally, the convex lenses are of the same size, and the distances between adjacent convex lenses are equal.

[0018] Optionally, the number of the aperture layers is one or more.

[0019] Optionally, the aperture holes of at least one of the aperture layers are the same size.

[0020] Optionally, when the number of the aperture layers is multiple, the aperture of the aperture hole gradually increases from top to bottom.

[0021] Optionally, when the number of the aperture layers is multiple, the aperture of the aperture hole gradually decreases from top to bottom.

[0022] Optionally, the surface of the photosensitive layer has a plurality of pixel areas, and the convex lens groups correspond one-to-one to the pixel areas.

[0023] Optionally, in at least one aperture layer of a single pixel area, the spacing between adjacent aperture holes is different.

[0024] Optionally, within a single pixel area, the sub-fields of view of all the focusing and collimating units constitute a unit field of view; within at least one aperture layer within a single pixel area, the farther away from the center of the unit field of view, the larger the distance between adjacent aperture holes.

[0025] Correspondingly, the present invention also provides a method for forming a fingerprint recognition device, comprising: providing a photosensitive layer, wherein the surface of the photosensitive layer has a horizontal pixel area; forming an aperture layer on the photosensitive layer, wherein the aperture layer has multiple aperture holes; forming a convex lens group on the aperture layer, wherein the projection of the convex lens group toward the photosensitive layer is located within the pixel area, the convex lens group includes multiple convex lenses, the convex lenses correspond to the aperture holes, the center of the bottom surface of the convex lens and the corresponding center of the aperture hole constitute a sub-field of view center axis, and any two sub-field of view center axes belonging to the same pixel area intersect in at least one vertical plane projection, and the intersection point is located above the convex lens group.

[0026] Optionally, the convex lens and the corresponding aperture hole constitute a focusing collimating unit, and the sub-fields of view of any two focusing collimating units belonging to the same pixel area overlap, and the boundary of the sub-field of view of the focusing collimating unit coincides with the path of the incident light with the maximum inclination angle that can pass through the aperture hole, and the inclination angle is the angle between the incident light and the central axis of the sub-field of view.

[0027] Optionally, the formation method also includes: forming a display panel above the convex lens group; on the top surface of the display panel, the ratio of the overlapping area of ​​the sub-fields of view of any two of the focusing and collimating units belonging to the same pixel area to the sub-field area of ​​a single focusing and collimating unit is equal to or greater than 50%.

[0028] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0029] In the technical solution of the fingerprint recognition device provided by the present invention, the convex lens group is located on the aperture layer and its projection onto the photosensitive layer is located within the pixel area. The convex lens group is adapted to receive and focus incident light, with the focused light then collimated by the aperture layer. The aperture layer has multiple apertures, through which some of the light output by the convex lens group passes, while the remaining light is filtered out by the aperture layer to improve the directional consistency of the light. The convex lens group includes multiple convex lenses, each corresponding to the aperture. The photosensitive layer in the pixel area receives light output by the convex lenses and apertures belonging to the same pixel area to form a fingerprint image for a single pixel area. The center of the bottom surface of each convex lens and the center of the corresponding aperture form the central axis of the sub-field of view. The projections of any two sub-field of view central axes belonging to the same pixel area on at least one vertical plane intersect, with the intersection point located above the convex lens group. Compared with the sub-field of view central axes of different focusing and collimating units being parallel, in the technical solution of the present invention, the convex lens and the corresponding aperture hole constitute a focusing and collimating unit, and the projections of the sub-field of view central axes of any two of the sub-fields belonging to the same pixel area intersect in at least one vertical plane, which is beneficial to improving the degree of overlap of the sub-fields of view of any two focusing and collimating units. The fingerprint image resolution of a single pixel area is related to the degree of overlap of the sub-fields of view of the focusing and collimating unit. The increased degree of overlap of the sub-fields of view of any two of the focusing and collimating units belonging to the same pixel area helps to improve the image resolution and thus improve the clarity of fingerprint imaging. Furthermore, the increased degree of overlap of the sub-fields of view of any two of the focusing and collimating units belonging to the same pixel area is beneficial to shielding crosstalk light from adjacent pixel areas, thereby reducing the risk of light crosstalk and further improving imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic structural diagram of a fingerprint recognition device according to an embodiment of the present invention;

[0031] Figure 2 is a schematic structural diagram of a fingerprint recognition device according to another embodiment of the present invention;

[0032] Figures 3 to 5 It is a schematic structural diagram corresponding to each step in an embodiment of a method for forming a fingerprint recognition device of the present invention. DETAILED DESCRIPTION

[0033] As can be seen from the background art, the structure of existing fingerprint recognition devices still needs to be improved.

[0034] Now, an analysis is conducted in conjunction with a fingerprint recognition device, which includes: a photosensitive layer, wherein the surface of the photosensitive layer has a horizontal pixel area; an aperture layer, located on the photosensitive layer, and the aperture layer has a plurality of aperture holes; a convex lens group, located on the aperture layer and whose projection toward the photosensitive layer is located within the pixel area, the convex lens group including a plurality of convex lenses, the convex lenses corresponding to the aperture holes, and the projection of the center of the bottom surface of the convex lens toward the aperture layer coincides with the center of the corresponding aperture hole.

[0035] The convex lens and the corresponding aperture constitute a focusing and collimating unit. The photosensitive layer of the pixel area receives light output by multiple focusing and collimating units belonging to the same pixel area to form a fingerprint image for a single pixel area. The center of the convex lens bottom surface and the center of the corresponding aperture constitute the sub-field of view central axis. Because the projection of the convex lens bottom surface center toward the aperture layer coincides with the center of the corresponding aperture, the central axes of all sub-fields of view are parallel. The sub-field of view of a single focusing and collimating unit is centered on the sub-field of view central axis. The parallelism of all sub-field of view central axes results in low overlap between the sub-fields of view of two different focusing and collimating units, resulting in relatively dispersed sub-fields of view within a single pixel area. The fingerprint image resolution of a single pixel area is related to the degree of overlap between the sub-fields of view of the focusing and collimating units. Low overlap between the sub-fields of view of the focusing and collimating units belonging to the same pixel area results in poor fingerprint image resolution and easily causes optical crosstalk between adjacent pixel areas, affecting fingerprint imaging quality.

[0036] The inventors have studied the above-mentioned problem and, through creative work, have noticed that the projections of the central axes of any two sub-fields of view belonging to the same pixel area intersect in at least one vertical plane, and the intersection point is located above the convex lens group, which helps to improve the fingerprint imaging quality.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0038] refer to Figure 1 A fingerprint recognition device 100 includes: a photosensitive layer 200, wherein the surface of the photosensitive layer 200 has a horizontal pixel area I; an aperture layer 300, located on the photosensitive layer 200, and the aperture layer 300 has a plurality of aperture holes 301; a convex lens group, located on the aperture layer 300 and whose projection toward the photosensitive layer 200 is located within the pixel area I, the convex lens group including a plurality of convex lenses 400, wherein the convex lenses 400 correspond to the aperture holes 301; and a display panel 500, wherein the display panel 500 is located above the convex lens group.

[0039] In this embodiment, the surface of the photosensitive layer 200 has a plurality of pixel regions I, each of which includes a photosensitive device for receiving light signals. Adjacent pixel regions I are spaced apart to form the entire photosensitive layer 200 . Figure 1 Only one pixel region I is shown.

[0040] In other embodiments, the pixel regions I are closely arranged and connected to form the entire photosensitive layer 200 .

[0041] The number of the convex lens groups is the same as the number of the pixel regions I, and the convex lens groups correspond to the pixel regions I.

[0042] When a finger presses the top surface of the display panel 500, light emitted from the display panel 500 is reflected by the finger surface to form reflected light. Because the finger surface has uneven ridges and valleys, the intensity of the reflected light formed at the ridges and valleys varies, so the reflected light carries fingerprint information.

[0043] The display panel 500, the convex lens group, the aperture layer 300, and the photosensitive layer 200 within a single pixel region I constitute a unit imaging group. The following describes a single unit imaging group: The reflected light carrying fingerprint information is incident from the display panel 500 onto the convex lens group. The convex lens group is adapted to receive and focus the incident light, which is then collimated by the aperture layer 300. The aperture layer 300 has multiple apertures 301. Some of the light emitted by the convex lens group passes through these apertures, while the remaining light is filtered (absorbed or reflected) by the aperture layer 300 to improve the directional consistency of the light. The convex lens 400 and the corresponding aperture 301 constitute a focusing and collimating unit. Multiple focusing and collimating units are present within a single pixel region I. The photosensitive layer 200 within this pixel region I receives light from multiple focusing and collimating units belonging to the same pixel region I, forming a fingerprint image for that pixel region I.

[0044] The center of the bottom surface of the convex lens 400 and the corresponding center of the aperture 301 form the sub-field of view central axis OO'. The sub-field of view 600 of the focusing and collimating unit is centered on the sub-field of view central axis OO'. The boundary of the sub-field of view 600 of the focusing and collimating unit coincides with the path of the incident light with the maximum inclination angle that can pass through the aperture 301. The inclination angle is the angle between the incident light and the sub-field of view central axis OO'.

[0045] The sub-field of view 600 of the focusing and collimating unit is suitable for measuring the tilt range of the light beam that can pass through the focusing and collimating unit. Incident light within the sub-field of view 600 is sequentially output through the convex lens 400 and the aperture 301 and received by the photosensitive layer 200. Incident light outside the sub-field of view 600 is filtered out by the aperture layer 300 during transmission and is therefore not received by the photosensitive layer 200.

[0046] The projections of the sub-field central axes OO' of any two focusing and collimating units belonging to the same pixel area I intersect in at least one vertical plane, and the intersection point is located above the convex lens group. The vertical direction here refers to the direction perpendicular to the surface of the photosensitive layer 200.

[0047] In this embodiment, the sub-field of view center axes OO′ of any two focusing and collimating units belonging to the same pixel area I intersect in at least one vertical plane projection, and the intersection point is located above the convex lens group. The vertical plane is a plane perpendicular to the surface of the photosensitive layer 200.

[0048] like Figure 1 As shown, the convex lens group includes three convex lenses 400. The three convex lenses 400 and the corresponding apertures 301 constitute three focusing and collimating units. The three focusing and collimating units belong to the same pixel region I. The sub-fields of view 600 of the three focusing and collimating units are represented by dashed lines of varying densities, and the central axis OO′ of the sub-field of view 600 is represented by a dotted line.

[0049] like Figure 1 As shown, the sub-field central axes OO′ of any two of the three focusing and collimating units intersect.

[0050] In other embodiments, the convex lenses 400 included in the convex lens assembly are arranged in an array on a two-dimensional plane. It is possible that the sub-field-of-view center axes OO' of the two focusing and collimating units are spatially staggered and parallel. Staggered and parallel means that the two sub-field-of-view center axes OO' are respectively on two vertically parallel planes, but the projections of the two sub-field-of-view center axes OO' onto any of the vertically parallel planes intersect. In this case, the sub-fields of view 600 of the two focusing and collimating units will also overlap.

[0051] Compared with the parallelism of the sub-field of view central axes OO′ of different focusing and collimating units, in the technical solution of the present invention, the projections of the sub-field of view central axes OO′ of any two focusing and collimating units belonging to the same pixel area I intersect in at least one vertical plane, which is beneficial to improving the overlap of the sub-fields of view 600 of any two focusing and collimating units belonging to the same pixel area I. The fingerprint image resolution of a single pixel area I is related to the overlap of the sub-field of view 600 of the focusing and collimating unit. The increased overlap of the sub-field of view 600 of any two focusing and collimating units belonging to the same pixel area I helps to improve the image resolution and thus improve the clarity of fingerprint imaging. Furthermore, the increased overlap of the sub-field of view 600 of any two focusing and collimating units belonging to the same pixel area I helps to shield the crosstalk light from the adjacent pixel area I, thereby reducing the risk of light crosstalk and further improving the imaging quality.

[0052] Within a single pixel region I, all of the sub-fields of view 600 of the focusing and collimating units constitute a unit field of view. The edge of the outermost sub-field of view 600 constitutes the edge of the unit field of view. Overlapping sub-fields of view 600 of any two focusing and collimating units within the same pixel region I helps reduce the unit field of view, thereby increasing image resolution and clarity while maintaining the same amount of light signal.

[0053] On the top surface of the display panel 500, the ratio of the overlapping area of ​​the sub-fields 600 of any two focusing and collimating units belonging to the same pixel area I to the area of ​​the sub-field 600 of a single focusing and collimating unit is equal to or greater than 50%.

[0054] When a finger presses the top surface of the display panel 500, the reflected light carrying the fingerprint information is incident on the convex lens group from the display panel 500. The top surface of the display panel 500 can be regarded as the emission surface of the incident light. Therefore, the larger the overlapping area of ​​the sub-fields of view 600 of the two focusing and collimating units on the top surface of the display panel 500, the higher the degree of overlap of the sub-fields of view 600 of the focusing and collimating units, and the higher the fingerprint image resolution of a single pixel area I. In this embodiment, on the top surface of the display panel 500, the ratio of the overlapping area of ​​the sub-fields of view 600 of any two focusing and collimating units belonging to the same pixel area I to the area of ​​the sub-field of view 600 of a single focusing and collimating unit is equal to or greater than 90%.

[0055] like Figure 1As shown, taking two of the focusing collimating units as an example, the area of ​​the sub-field of view 600 of the focusing collimating unit on the left at the top surface of the display panel 500 is S1, the area of ​​the sub-field of view 600 of the focusing collimating unit in the middle at the top surface of the display panel 500 is S2, and the overlapping area of ​​the sub-fields of view 600 of the two focusing collimating units on the left and in the middle at the top surface of the display panel 500 is S12, wherein the ratio of S12 to S1 is equal to or greater than 90%, and the ratio of S12 to S2 is equal to or greater than 90%.

[0056] In other embodiments, within a single pixel region I, the sub-field-of-view central axes OO' of all the focusing and collimating units intersect at the same point, with the intersection point located above the convex lens assembly. When the sub-field-of-view central axes OO' of all the focusing and collimating units within a single pixel region I intersect at the same point, this helps maximize the overlap of the sub-fields 600 of any two focusing and collimating units within the same pixel region I, thereby improving fingerprint image clarity and reducing the risk of optical crosstalk between adjacent pixel regions I.

[0057] In this embodiment, the display panel 500 includes: a panel body 510; and a protective glass 520, wherein the protective glass 520 covers the top surface of the panel body 510. The top surface of the protective glass 520 serves as a finger pressing surface.

[0058] The panel body 510 is an OLED (Organic Light-Emitting Diode) display panel and also includes capacitive touch sensing for detecting finger touches. The OLED panel material includes organic semiconductor materials and luminescent materials. Under the influence of an electric field, electrons and holes in the organic semiconductor material combine to form excitons, which excite the luminescent material molecules to emit visible light.

[0059] In this embodiment, an air gap 501 is provided between the display panel 500 and the convex lens assembly. Compared to using an adhesive layer to bond the convex lens assembly to the bottom surface of the display panel, maintaining the air gap 501 has a minimal effect on the optical path. There is no need to worry about the adhesive layer itself affecting the optical path, or about bubbles or impurities within the adhesive layer affecting the optical path, thus helping to ensure fingerprint imaging quality.

[0060] In this embodiment, the thickness of the air gap 501 is 0.1 mm to 0.6 mm. If the thickness of the air gap 501 is too large, incident light from adjacent pixel regions I may easily cause crosstalk. If the thickness of the air gap 501 is too small, the display panel 500 may easily touch the top of the convex lens 400 when pressed, increasing the risk of wear on the top of the convex lens 400.

[0061] In other embodiments, a light-transmitting adhesive layer with a low refractive index can also be used to bond the display panel 500 to the convex lens assembly. This makes the structure more robust and the overall thickness of the display and fingerprint module thinner. Since the convex lens is required to achieve the function of converging light, it is necessary to select a material with a lower refractive index than the convex lens material for bonding. For example, if the refractive index of the convex lens material is 1.7, the refractive index of the adhesive layer material should be 1.3.

[0062] In this embodiment, the top surface of the convex lens 400 is in the shape of a spherical crown, and the bottom surface of the convex lens 400 is in the shape of a circular plane.

[0063] In this embodiment, the convex lenses 400 are of the same size. Within a single pixel region I, adjacent convex lenses 400 are spaced evenly apart. The convex lenses 400 having the same size and equal spacing simplify the manufacturing process, improve batch stability, and increase production yield.

[0064] In this embodiment, the fingerprint recognition device 100 also includes: a first light-transmitting medium layer 710, the first light-transmitting medium layer 710 is located between the convex lens group and the aperture layer 300, the first light-transmitting medium layer 710 covers the top surface of the aperture layer 300, and the convex lens group covers the top surface of the first light-transmitting medium layer 710.

[0065] In this embodiment, the aperture layer 300 is made of a light-absorbing material. Light that is obliquely incident on the surface of the aperture layer 300, or light that is obliquely incident on the wall of the aperture 301 during the process of passing through the aperture 301, will be absorbed by the aperture layer 300 and thus filtered out.

[0066] The number of the aperture layer 300 is one or more. In this embodiment, the number of the aperture layer 300 is multiple. Specifically, the aperture layer 300 includes a first aperture layer 310 and a second aperture layer 320, and the second aperture layer 320 is located above the first aperture layer 310.

[0067] The apertures 301 of at least one aperture layer 300 are of the same size. In this embodiment, the apertures 301 of each aperture layer 300 are of the same size, which helps ensure the amount of light signal received by the photosensitive layer 200 and prevents variations in the size of the apertures 301 from causing a reduction in light signal intensity and thus affecting imaging quality. Furthermore, when the apertures 301 are of the same size, the manufacturing process is simplified, batch stability is improved, and production yield is higher. In this embodiment, the apertures 301 of the first aperture layer 310 are of the same size, and the apertures 301 of the second aperture layer 320 are of the same size.

[0068] In this embodiment, the aperture layers 300 are multiple layers, with the apertures 301 gradually increasing in diameter from top to bottom. The aperture layers 300 in the lower layers are adapted to filter out crosstalk from adjacent pixel regions I. Specifically, the apertures 301 in the first aperture layer 310 are larger than the apertures 301 in the second aperture layer 320. The first aperture layer 310 is adapted to filter out crosstalk from the light output by the second aperture layer 320.

[0069] refer to Figure 2 In other embodiments, when the number of the aperture layer 300 is multiple, the aperture of the aperture hole 301 gradually decreases from top to bottom. The multiple aperture layers 300 are suitable for performing multiple collimation processes on the light to further improve the consistency of the light direction.

[0070] It should be noted that in Figure 2 In the embodiment shown, Figure 1 As in the illustrated embodiment, the sub-field-of-view central axes OO' of any two of the three focusing and collimating units intersect. In another embodiment, the convex lenses 400 included in the convex lens assembly are arranged in an array on a two-dimensional plane, and it is possible that the sub-field-of-view central axes OO' of two focusing and collimating units may be spatially staggered and parallel.

[0071] Furthermore, if Figure 2 As shown, on the top surface of the display panel 500, the ratio of the overlapping area of ​​the sub-fields of view 600 of any two focusing collimating units belonging to the same pixel area I to the area of ​​the sub-field of view 600 of a single focusing collimating unit is equal to or greater than 50%.

[0072] In at least one layer of the aperture layer 300 of a single pixel area I, the distances between adjacent aperture holes 301 are different, and the farther away from the center of the unit field of view, the larger the distance between adjacent aperture holes 301.

[0073] In this embodiment, reference Figure 1 and Figure 2 Within each aperture layer 300 of a single pixel region I, the spacing between adjacent aperture holes 301 varies. Within each aperture layer 300 of a single pixel region I, the farther from the center of the unit field of view, the more dispersed the arrangement of the aperture holes 301, and the larger the spacing between adjacent aperture holes 301. The closer to the center of the unit field of view, the more concentrated the arrangement of the aperture holes 301, and the smaller the spacing between adjacent aperture holes 301. This allows any two sub-fields of view 600 of the focusing and collimating units belonging to the same pixel region I to overlap.

[0074] The fingerprint recognition device 100 also includes: a second light-transmitting medium layer 720, which is located between the first aperture layer 310 and the second aperture layer 320, and the second light-transmitting medium layer 720 covers the top surface of the first aperture layer 310, and the second aperture layer 320 covers the top surface of the second light-transmitting medium layer 720.

[0075] The fingerprint recognition device 100 further includes a third light-transmitting medium layer 730, which is located between the aperture layer 300 and the photosensitive layer 200. Specifically, the third light-transmitting medium layer 730 covers the top surface of the photosensitive layer 200, and the first aperture layer 310 covers the top surface of the third light-transmitting medium layer 730.

[0076] Figures 3 to 5 1 is a schematic structural diagram corresponding to each step in an embodiment of a method for forming a fingerprint recognition device 100 of the present invention.

[0077] refer to Figure 3 , providing a photosensitive layer 200, wherein the surface of the photosensitive layer 200 has a horizontal pixel area I.

[0078] In this embodiment, the surface of the photosensitive layer 200 has a plurality of pixel regions I. Figure 3 Only one pixel region I is shown.

[0079] refer to Figure 4 , an aperture layer 300 is formed on the photosensitive layer 200, and the aperture layer 300 has a plurality of aperture holes 301.

[0080] In this embodiment, before forming the aperture layer 300, it also includes: forming a third light-transmitting medium layer 730 covering the top surface of the photosensitive layer 200, and the aperture layer 300 covers the top surface of the third light-transmitting medium layer 730.

[0081] The number of the aperture layer 300 is one or more. When the number of the aperture layer 300 is multiple, the aperture layers 300 of different layers have corresponding aperture holes 301.

[0082] In this embodiment, the aperture layer 300 includes a first aperture layer 310 and a second aperture layer 320 located on the first aperture layer 310 .

[0083] In this embodiment, the formation method further includes: forming a second light-transmitting medium layer 720 between the first aperture layer 310 and the second aperture layer 320.

[0084] In this embodiment, the aperture layers 300 are multiple layers, and the apertures 301 gradually increase in diameter from top to bottom. Specifically, the apertures 301 of the first aperture layer 310 are larger than the apertures 301 of the second aperture layer 320.

[0085] In other embodiments, when the number of the aperture layer 300 is multiple, the aperture of the aperture hole 301 gradually decreases from top to bottom.

[0086] refer to Figure 5 A convex lens group is formed on the aperture layer 300, and the projection of the convex lens group toward the photosensitive layer 200 is located within the pixel area I; a display panel 500 is formed above the convex lens group.

[0087] In this embodiment, before forming the convex lens group, it also includes: forming a first light-transmitting medium layer 710 covering the top surface of the aperture layer 300, and the convex lens group covers the top surface of the first light-transmitting medium layer 710.

[0088] In this embodiment, the number of the convex lens groups is the same as the number of the pixel regions I, and the convex lens groups correspond to the pixel regions I one-to-one.

[0089] The convex lens group includes a plurality of convex lenses 400 , and the convex lenses 400 belonging to the same convex lens group are located in the same pixel area I.

[0090] The convex lens 400 corresponds to the aperture 301. The convex lens 400 and the corresponding aperture 301 constitute a focusing and collimating unit.

[0091] like Figure 5 As shown, the convex lens group includes three convex lenses 400, and the three convex lenses 400 and the corresponding apertures 301 constitute three focusing and collimating units. The sub-fields of view 600 of the three focusing and collimating units are respectively indicated by dashed lines of different densities.

[0092] The center of the bottom surface of the convex lens 400 and the center of the corresponding aperture 301 form a sub-field of view center axis OO′, and the sub-field of view center axis OO′ of the sub-field of view 600 is indicated by a dot-dash line.

[0093] The sub-field center axes OO′ of any two focusing and collimating units belonging to the same pixel area I intersect in projections of at least one vertical plane, and the intersection point is located above the convex lens group.

[0094] In this embodiment, the sub-field of view center axes OO′ of any two focusing and collimating units belonging to the same pixel area I intersect in at least one vertical plane projection, and the intersection point is located above the convex lens group. The first plane is a plane perpendicular to the surface of the photosensitive layer 200.

[0095] In this embodiment, the sub-fields of view 600 of any two focusing and collimating units belonging to the same pixel area I overlap, and the boundaries of the sub-fields of view 600 of the focusing and collimating units coincide with the path of the incident light with the maximum inclination angle that can pass through the aperture 301, and the inclination angle is the angle between the incident light and the central axis OO′ of the sub-field of view.

[0096] In this embodiment, on the top surface of the display panel 500, the ratio of the overlapping area of ​​the sub-fields 600 of any two focusing and collimating units belonging to the same pixel area I to the area of ​​the sub-field 600 of a single focusing and collimating unit is equal to or greater than 50%.

[0097] In this embodiment, an air gap 501 is provided between the display panel 500 and the convex lens group, and the thickness of the air gap 501 is 0.1 mm to 0.6 mm.

[0098] In this embodiment, the display panel 500 includes: a panel body 510 ; and a protective glass 520 . The protective glass 520 covers the top surface of the panel body 510 .

[0099] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A fingerprint recognition device, characterized in that: include: A photosensitive layer, wherein a surface of the photosensitive layer has a plurality of pixel areas in a horizontal direction; an aperture layer, located on the photosensitive layer, and having a plurality of aperture holes; A convex lens group is located on the aperture layer and its projection toward the photosensitive layer is located in the pixel area. The convex lens group corresponds to the pixel area one by one. The convex lens group includes a plurality of convex lenses, each corresponding to the aperture hole. The convex lens and the corresponding aperture hole constitute a focusing collimating unit. The center of the bottom surface of the convex lens and the center of the corresponding aperture hole constitute a sub-field of view center axis. In a single pixel area, the sub-fields of view of all the focusing collimating units constitute a unit field of view. In at least one layer of the aperture layer in a single pixel area, the farther away from the center of the unit field of view, the greater the distance between adjacent aperture holes, so that the projections of any two sub-field of view center axes belonging to the same pixel area intersect in at least one vertical plane, and the intersection point is located above the convex lens group, so that the sub-fields of view of any two focusing collimating units belonging to the same pixel area overlap.

2. The fingerprint recognition device according to claim 1, wherein: The sub-field of view boundary of the focusing and collimating unit coincides with the path of the incident light with the maximum inclination angle that can pass through the aperture, and the inclination angle is the angle between the incident light and the central axis of the sub-field of view.

3. The fingerprint recognition device according to claim 2, wherein: Also includes: A display panel is located above the convex lens group.

4. The fingerprint recognition device according to claim 3, wherein: On the top surface of the display panel, a ratio of an overlapping area of ​​sub-fields of view of any two focusing and collimating units belonging to the same pixel area to an area of ​​a sub-field of view of a single focusing and collimating unit is equal to or greater than 50%.

5. The fingerprint recognition device according to claim 4, wherein: On the top surface of the display panel, a ratio of an overlapping area of ​​sub-fields of view of any two focusing and collimating units belonging to the same pixel area to an area of ​​a sub-field of view of a single focusing and collimating unit is equal to or greater than 90%.

6. The fingerprint recognition device according to any one of claims 1 to 5, characterized in that: The central axes of all the sub-fields of view belonging to the same pixel area intersect at the same point.

7. The fingerprint recognition device according to claim 3, wherein: An air gap is provided between the display panel and the convex lens group.

8. The fingerprint recognition device according to claim 7, wherein: The thickness of the air gap is 0.1 mm to 0.6 mm.

9. The fingerprint recognition device according to claim 3, wherein: The display panel includes: Panel body; A protective glass covers the top surface of the panel body.

10. The fingerprint recognition device according to claim 1, wherein: The convex lenses are of the same size, and the distances between adjacent convex lenses are equal.

11. The fingerprint recognition device according to claim 2, wherein: The number of the aperture layer is one or more layers.

12. The fingerprint recognition device according to claim 11, wherein: The aperture holes of at least one of the aperture layers have the same size.

13. The fingerprint recognition device according to claim 12, wherein: When the number of the aperture layers is multiple, the aperture of the aperture hole gradually increases from top to bottom.

14. The fingerprint recognition device according to claim 12, wherein: When the number of the aperture layers is multiple, the aperture of the aperture hole gradually decreases from top to bottom.

15. A method for forming a fingerprint recognition device, characterized in that: include: Providing a photosensitive layer, wherein the surface of the photosensitive layer has a plurality of pixel areas in a horizontal direction; forming an aperture layer on the photosensitive layer, wherein the aperture layer has a plurality of aperture holes; A convex lens group is formed on the aperture layer, and the projection of the convex lens group toward the photosensitive layer is located in the pixel area. The convex lens group corresponds to the pixel area one by one, and the convex lens group includes a plurality of convex lenses, and the convex lenses correspond to the aperture holes. The convex lenses and the corresponding aperture holes constitute a focusing collimating unit, and the center of the bottom surface of the convex lens and the center of the corresponding aperture hole constitute a sub-field of view center axis. In a single pixel area, the sub-fields of view of all the focusing collimating units constitute a unit field of view; in at least one layer of the aperture layer in a single pixel area, the farther away from the unit field of view center, the greater the distance between adjacent aperture holes, so that the projections of any two sub-field of view center axes belonging to the same pixel area intersect in at least one vertical plane, and the intersection point is located above the convex lens group, so that the sub-fields of view of any two focusing collimating units belonging to the same pixel area overlap.

16. The method for forming a fingerprint recognition device according to claim 15, wherein: The sub-field of view boundary of the focusing and collimating unit coincides with the path of the incident light with the maximum inclination angle that can pass through the aperture, and the inclination angle is the angle between the incident light and the central axis of the sub-field of view.

17. The method for forming a fingerprint recognition device according to claim 16, wherein: Also includes: forming a display panel above the convex lens group; On the top surface of the display panel, a ratio of an overlapping area of ​​sub-fields of view of any two focusing and collimating units belonging to the same pixel area to an area of ​​a sub-field of view of a single focusing and collimating unit is equal to or greater than 50%.

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