Fingerprint identification device and electronic terminal

Abstract

The application provides a fingerprint identification device with small thickness and low cost and an electronic terminal. The fingerprint identification device comprises an optical film and an image sensor arranged along a first direction and at a first distance. The optical film comprises a first area and a second area with different light transmittances, and the first area and the second area form a first pattern. When the optical film receives light reflected from a first object, the optical film converts the light into an optical image with the first pattern and transmits the optical image to the image sensor. The image sensor is configured to receive an optical signal in the optical image and convert the optical signal into an electrical signal, and the electrical signal is used to construct an image of a surface of the first object reflecting the light. In an embodiment of the application, an electronic terminal comprising the aforementioned fingerprint identification device is provided.

Description

Technical Field

[0001] This application relates to the fields of image display and optical image sensing technology, and in particular to a fingerprint recognition device and an electronic terminal. Background Technology

[0002] Currently, for electronic terminals capable of performing self-fingerprint recognition verification, fingerprint sensing modules all use optical lenses to process the received light before providing it to the fingerprint sensor. However, the material of these optical lenses makes further thickness reduction difficult, and the lenses themselves are also expensive. Therefore, fingerprint recognition modules, with limited room for thickness reduction and high cost, cannot meet users' demands for thinner and lower-cost electronic devices. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a fingerprint recognition device and an electronic terminal, which results in a fingerprint recognition device with a smaller overall thickness and lower cost.

[0004] In a first aspect, embodiments of this application provide a fingerprint recognition device, which includes an optical film and an image sensor disposed along a first direction and spaced apart by a first distance. The optical film includes a first region and a second region, the first region and the second region having different light transmittances. The first region and the second region constitute a first pattern. When the optical film receives light reflected from a first object, it converts the light into an optical image having the first pattern and transmits it to the image sensor. The image sensor receives optical signals in the optical pattern and converts the optical signals into electrical signals. The electrical signals are used to construct an image of the surface of the first object reflecting the light.

[0005] In one embodiment of this application, the range of the first distance is less than 0.5 mm.

[0006] In one embodiment of this application, the thickness of the optical film along the first direction is less than 500 micrometers.

[0007] In one embodiment of this application, the optical film and the first object are spaced apart by a second distance along the first direction, and the range of the second distance is 0.05 to 5 millimeters.

[0008] In one embodiment of this application, the first region and the second region are alternately arranged adjacent to each other starting from the center position of the optical film, and the first region is a closed shape composed of curves or straight lines, and the second region is a closed shape composed of curves or straight lines.

[0009] In one embodiment of this application, the optical film includes at least two sub-regions, each sub-region including the first region and the second region, and the first region and the second region are closed rings or squares.

[0010] In one embodiment of this application, the first region and the second region are alternately adjacent to each other starting from the center of the optical film, and the first region is composed of segmented curves with the same or different curvatures, and the second region is composed of segmented curves with the same or different curvatures.

[0011] In one embodiment of this application, the first region and the second region are disposed opposite to each other, and both the first region and the second region are involute spiral shapes.

[0012] In one embodiment of this application, the optical film includes at least two sub-regions, each sub-region including the first region and the second region, and the first region and the second region are involute spiral shapes.

[0013] In one embodiment of this application, the optical film includes at least two sub-regions, and the first region and the second region included in each of the sub-regions have different shapes.

[0014] In one embodiment of this application, the aforementioned at least two regions include a first sub-region and a second sub-region. Within the first sub-region, both the first and second regions are closed squares composed of curves or straight lines, and within the second sub-region, the first and second regions are closed rings composed of curves or straight lines. Alternatively, within the first sub-region, both the first and second regions are closed squares or rings composed of curves or straight lines, and within the second sub-region, the first and second regions are involute spiral shapes composed of piecewise curves with the same or different curvatures.

[0015] In one embodiment of this application, the above-mentioned at least two regions include a first sub-region, a second sub-region, and a third sub-region.

[0016] Within the aforementioned first sub-region, both the first region and the second region are closed squares composed of curves or straight lines;

[0017] Within the aforementioned second sub-region, the aforementioned first region and the aforementioned second region form a closed ring composed of curves or straight lines;

[0018] Within the aforementioned third sub-region, the aforementioned first region and the aforementioned second region are involute spiral shapes composed of piecewise curves with the same or different curvatures.

[0019] In one embodiment of this application, the optical film is made of resin, glass, or high light transmittance; or a combination of one or more materials selected from high light transmittance and low reflectance, and high light transmittance and high reflectance.

[0020] In one embodiment of this application, the fingerprint recognition device further includes a first light source, which provides auxiliary light. The auxiliary light is transmitted to the first object through the optical film. The first light source and the image sensor are disposed on the surface of a support member, which supports the first light source and the image sensor. Alternatively, the first light source is a display screen, which displays an image and is disposed on the side of the optical film away from the image sensor. The auxiliary light provided by the display screen when displaying the image is directly transmitted to the first object.

[0021] In one embodiment of this application, the distance between the first surface of the optical film and the surface of the support member in the first direction is less than 1 mm.

[0022] In one embodiment of this application, the optical film includes a first surface and a second surface disposed opposite to each other in the first direction. The first surface is farther away from the image sensor than the second surface, and the first surface undergoes a first optical processing to collect light within a preset frequency band.

[0023] In one embodiment of this application, the optical film includes a first surface and a second surface disposed opposite to each other in the first direction. The first surface is farther away from the image sensor than the second surface, and the second surface undergoes a second optical processing to collect light within a preset frequency band.

[0024] In one embodiment of this application, the image sensor includes a third surface facing the optical film, and the third surface undergoes a third optical processing to collect light within a preset frequency band.

[0025] In one embodiment of this application, the optical film includes a plurality of conductive electrodes, which are used to receive a first voltage. The first voltage controls the transmittance of different regions of the optical film to form different patterns.

[0026] In one embodiment of this application, the phase, area size, and inter-area spacing of the pattern formed by the optical film at different time points are different.

[0027] In one embodiment of this application, the optical film includes a first substrate layer, a dielectric layer, and a second substrate layer stacked sequentially, with a cavity formed between the first substrate layer and the second substrate layer to accommodate the dielectric layer. The second substrate layer has a plurality of matrix-arranged pixel regions and a plurality of conductive pads. Each pixel region has a driving circuit, which is electrically connected to the conductive pads and receives a first voltage through the conductive pads. The driving circuit generates electric fields of different intensities under different first voltage controls. The dielectric layer has different transmittances under different electric fields. When different pixel regions receive different driving voltages, they form the first patterns with different transmittances.

[0028] In one embodiment of this application, the first substrate layer is further used to filter out light of a preset frequency band and wavelength.

[0029] In one embodiment of this application, different first voltages are provided to the aforementioned multiple pixel units at different time periods and the aforementioned patterns are presented at different times, thereby effectively improving the ability of the optical film to flexibly present different patterns.

[0030] Secondly, this application provides an electronic terminal, which includes a display screen and the aforementioned fingerprint recognition device. The display screen is disposed along the first direction on the side of the optical film away from the image sensor, and the display screen and the optical film are spaced apart by a third distance, the third distance being 0.005 to 5 mm. Light reflected from the first object is transmitted through the display screen to the optical film. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the planar structure of the electronic terminal in the first embodiment of this application;

[0032] Figure 2 As shown in one embodiment of this application Figure 1 A schematic diagram of the cross-sectional structure of the electronic terminal along line II;

[0033] Figure 3 As shown in the first embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0034] Figure 4 As in the second embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0035] Figure 5 As in the third embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0036] Figure 6 As shown in the fourth embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0037] Figure 7 As shown in the fourth embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0038] Figure 8 As shown in the fourth embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0039] Figure 9 As in the fifth embodiment of this application Figure 2 A schematic diagram of the optical film pattern shown;

[0040] Figure 10 As in the fifth embodiment of this application Figure 2 A schematic diagram of the pattern shape of the optical film shown;

[0041] Figure 11 As in the sixth embodiment of this application Figure 1 A schematic diagram of the cross-sectional structure of the electronic terminal along line II;

[0042] Figure 12 As shown in the seventh embodiment of this application Figure 1 A schematic diagram of the cross-sectional structure of the electronic terminal along line II;

[0043] Figure 13 for Figure 12 A schematic diagram of the planar structure of the second substrate layer is shown;

[0044] Figure 14 for Figure 12 A top view of the fingerprint recognition device shown;

[0045] Figure 15 As in the eighth embodiment of this application Figure 1 A schematic diagram of the cross-sectional structure of the electronic terminal along line II;

[0046] Figure 16 For example Figure 15 The diagram shows the pattern and shape of the display screen.

[0047] Figure 17 For example Figure 16 The diagram shows the distribution of light intensity in two regions with different light intensities on the display screen. Detailed Implementation

[0048] The present application will now be described with reference to specific embodiments.

[0049] Please see Figure 1 , Figure 1This is a schematic diagram of the planar structure of the electronic terminal in the first embodiment of this application. Figure 1 As shown, the electronic terminal 100 is used to perform image display and also receives touch operations from the user's finger. During a touch operation, the location of the touch operation received by the electronic terminal 100 can be detected simultaneously, and the image of the finger touching the electronic terminal 100 can be detected and reconstructed. In this embodiment, the image of the finger touching the electronic terminal 100 includes an image of the object to be sensed. The image of the object to be sensed includes the detection and reconstruction of a fingerprint to identify the fingerprint of the finger touching the electronic terminal 100. In this embodiment, the first object B is a finger.

[0050] The electronic terminal 100 includes a display area AA and a non-display area NA. The display area AA is used for image display, and the non-display area NA is located at the edge of the display area AA and is used to house non-display components. The display area AA includes multiple pixel units P arranged in a matrix. The multiple pixel units P, in conjunction with a driving circuit (not shown), perform image display by emitting light according to data signals. In this embodiment, the pixel unit P can be an organic light-emitting diode (OLED) or a liquid crystal. The pixel unit P includes multiple sub-image display units (not shown) that emit light of different colors. The multiple sub-image display units of different colors cooperate to make the pixel unit emit colored light of different brightness. In this embodiment, a fingerprint recognition device 10 can be set at any position in the display area AA or the non-display area NA. The fingerprint recognition device 10 detects the fingerprint of the finger of the touch electronic terminal 100 and further reconstructs the detected fingerprint image to recognize the fingerprint of the finger of the touch electronic terminal 100.

[0051] In this embodiment, the electronic terminal 100 can be a mobile communication terminal, such as a mobile phone or a tablet computer, or other terminals that need to perform image sensing.

[0052] Please see Figure 2 , Figure 2 As shown in one embodiment of this application Figure 1 A schematic diagram of the cross-sectional structure of the electronic terminal 100 along line II.

[0053] like Figure 2 As shown, in the electronic terminal 100, the display screen DS and the optical film 11, image sensor 13, support member 15 and first circuit board 17 of the fingerprint recognition device 10 are stacked sequentially from top to bottom along the first direction F1.

[0054] The optical film 11 is used to convert light reflected from a finger into an optical signal of a first pattern and transmit it to the image sensor 13. The image sensor 13 receives the optical signal of the first pattern and converts it into an electrical signal, which is used to construct an image of the surface on which the finger reflects the light. In this embodiment, the image sensor 13 can be implemented as a charge-coupled device (CCD) sensor or a complementary metal-oxide-semiconductor (CMOS) image sensor.

[0055] A support member 15 supports an image sensor 13. A first circuit board 17 is disposed adjacent to the support member 15 and is electrically connected to the image sensor 13. The functional circuitry on the first circuit board 17 provides driving power and control signals to the image sensor 13, driving and controlling the image sensor 13 to convert optical signals into electrical signals, and transmitting the received electrical signals from the image sensor 13 to an image processor (not shown). This allows the image processor to amplify, filter, and process the electrical signals, and construct an image of the surface of a finger reflecting the light based on the processed electrical signals. In this embodiment, the first circuit board 17 can be a flexible circuit board and directly electrically connected to the image sensor 13. Alternatively, the first circuit board 17 and the image processor 13 can also be electrically connected via a board-to-board connector.

[0056] In this embodiment, the first object B is illustrated using a finger as an example. The electrical signal is used to construct an image of the texture on the surface of the finger, that is, to construct a fingerprint image through the electrical signal.

[0057] In this embodiment, the image sensor 13 and the optical diaphragm 11 are spaced apart by a first distance d1 along a first direction F1. In this embodiment, the first distance d1 ranges from 0.001 to 0.5 millimeters (mm), and the optical diaphragm 11 and the finger are spaced apart by a second distance d2 along the first direction F1. The second distance ranges from 0.05 to 5 millimeters (mm). The thickness of the optical diaphragm along the first direction F1 is less than 500 micrometers (μm). Therefore, the overall thickness of the fingerprint recognition device 10 along the first direction F1 is less than 1 millimeter (mm).

[0058] In this embodiment, the optical film 11 is made of resin, glass, or a material with high light transmittance, or a combination of one or more of the following: high light transmittance and low reflectance, or high light transmittance and high reflectance. Alternatively, the optical film 11 can be constructed from at least one of the following: a Gapper zone plate, a Fresnel zone plate, or a mask. Or, the optical film 11 can be composed of a combination of various materials to form a material with locally high light transmittance and locally high reflectance.

[0059] In this embodiment, the optical diaphragm 11 includes a first surface 111 and a second surface 112 opposite to each other in the first direction F1, wherein the first surface 111 is farther away from the image sensor 13 than the second surface 112. A first optical processing is performed on the first surface 111 to collect light within a preset frequency band, which can be set according to actual needs. In this embodiment, the distance between the first surface 111 of the optical diaphragm 11 and the surface of the support 15 where the image sensor 13 is mounted is less than 0.5 millimeters (mm).

[0060] Alternatively, a second optical processing is performed on the second surface 112 to collect light within a preset frequency band.

[0061] Alternatively, the image sensor 13 may include a third surface 131, which is opposite to the optical diaphragm 11, that is, the optical diaphragm 11 is disposed adjacent to the third surface 131 of the image sensor 13, wherein the third surface 131 performs a third optical processing to collect light within a preset frequency band range.

[0062] The display screen DS includes a fifth surface DS1 and a sixth surface DS2 opposite to each other in the first direction F1. The fifth surface DS1 is used to receive a finger; that is, when a finger operates the mobile terminal 10, it is adjacent to or in direct contact with the fifth surface DS1 of the display screen DS. The sixth surface DS2 is adjacent to the optical film 11 than the fifth surface DS1.

[0063] In this embodiment, the fifth surface DS1 performs a fourth optical processing to collect light within a preset frequency band range.

[0064] Alternatively, the sixth surface DS2 performs the fifth optical processing to collect light within a preset frequency range.

[0065] Among them, the optical processing in the first to fifth optical processing can be coating, applying liquids, powders, particles, or other materials, or removing some materials from the surface of the optical element.

[0066] To convert the received light into an optical signal of the first pattern, the optical diaphragm 11 is patterned, that is, the optical diaphragm 11 is patterned according to the first pattern. Thus, light reflected from the finger and entering the optical diaphragm 11 forms an optical signal of the first pattern after passing through its own pattern. In this embodiment, the patterned optical diaphragm 11 has different transmittances in different areas, thereby forming a pattern with a regular brightness distribution after light passes through the optical diaphragm 11. The optical signal of the first pattern obtained through the optical diaphragm 11 has a richer hierarchy of light intensity compared to an optical diaphragm with a single transmittance. That is, the patterned optical signal of the first pattern can superimpose the intensity of light within a preset frequency band, thereby enabling the image sensor 13 to have enough light signals to perform the conversion, ultimately improving the quality of the electrical signal obtained by the image sensor 13 after converting the light signal and the image composed of the electrical signal.

[0067] In this embodiment, the patterning of the optical film 11 involves physically polishing or chemically etching the surface of the optical film 11 according to a preset pattern shape to form areas with different light transmittance. Of course, in other embodiments of this application, the patterning of the optical film 11 can also be formed using other processes or methods, and is not limited to the foregoing examples.

[0068] In addition, the optical film 11 itself is thinner, so the space required for the optical film 11 is correspondingly smaller, which results in a thinner fingerprint recognition device 10 and a relatively lower cost of the optical film 11, thereby reducing the cost of the fingerprint recognition device 10 and the electronic terminal 100.

[0069] On the one hand, the patterned shape of the optical film 11 can be set according to actual needs, and the patterned shape of the optical film 11 can be composed of at least two regions with different transmittance. That is, the patterned shape of the optical film 11 includes two, three, four or other numbers of regions with different transmittance, and the number of regions with different transmittance can be set according to actual needs.

[0070] On the other hand, after the optical film 11 is patterned, the transmittance of each light-transmitting region can be the same, or the transmittance of each light-transmitting region can vary according to a preset rule. For example, taking the center point of the optical film 11 as a reference point, the transmittance of each light-transmitting region gradually decreases or gradually increases as the distance from the center point gradually increases. The transmittance of each light-transmitting region, taking the center point of the optical film 11 as a reference point, varies according to rules such as sine, cosine, tangent, or cotangent as the distance from the center point of the optical film 11 changes.

[0071] The adjacent positions of two regions with different transmittances are formed by points with approximate transmittances, creating an adjacency band X. The width of the adjacency band X is determined by the number of points with approximate transmittances. For example, if the number of points with approximate transmittances in two different locations of the adjacency band X is different, then two adjacency bands X with different widths are formed.

[0072] In one possible implementation, where the transmittance within each light-transmitting area can also vary according to a preset rule, for light-transmitting areas of the same range, the transmittance changes in the same trend as the distance from the center point gradually increases. However, for light-transmitting areas of different ranges, the transmittance changes in the opposite direction as the distance from the center point gradually increases. For example, for light-transmitting areas with a transmittance of 85%-95%, the transmittance gradually decreases as the distance from the center point gradually increases, while for light-transmitting areas with a transmittance of 5%-10%, the transmittance gradually increases as the distance from the center point gradually increases. Please refer to [link to relevant documentation]. Figure 3 As shown in the first embodiment of this application Figure 2 A schematic diagram of the pattern shape of the optical film 11a shown.

[0073] like Figure 3 As shown, the optical film 11a includes a first region 101 and a second region 102 with different transmittances, i.e., the transmittances of the first region 101 and the second region 102 are different. In this embodiment, the transmittance of the first region 101 is greater than that of the second region 102. For example, the transmittance of the first region 101 is 99%, and the transmittance of the second region 102 is 85%. The first region 101 and the second region 102 are alternately arranged adjacent to each other in a direction extending outward from the center point O1 of the optical film 11a to the edge region.

[0074] In this embodiment, as Figure 3 As shown, the first region 101 may include three sub-regions: a first sub-region 1011, a third region 1012, and a fifth sub-region 1013, which are located at different positions and whose distances from the center point O1 gradually increase. The second region 102 includes three sub-regions: a second sub-region 1021, a fourth sub-region 1012, and a sixth sub-region 1013, which are located at different positions and whose distances from the center point O1 gradually increase. In other embodiments of this application, the number of sub-regions included in the first region 101 and the second region 102 can be set according to specific needs and is not limited to a fixed number. Figure 3 The number shown is limited; for example, the first region 101 and the second region 102 may also include 4, 5, 6, or other partitions.

[0075] The three sub-regions 1011-1013 of the first region 101 are each composed of piecewise curves with the same or different curvatures, and the three sub-regions 1021-1023 of the second region 102 are each composed of piecewise curves with the same or different curvatures. Alternatively, the three sub-regions 1011-1013 of the first region 101 can each be a closed figure composed of curves or straight lines with arbitrary curvatures, and correspondingly, the three sub-regions 1021-1023 of the second region 102 can each be a closed figure composed of curves or straight lines with arbitrary curvatures. Alternatively, the first region 101 is an involute spiral shape, and correspondingly, the second region 102 is an involute spiral shape; that is, the first region 101 and the second region 102 are formed by rotating line segments whose curvature gradually decreases from the center point.

[0076] like Figure 3 As shown, the three partitions 1011 to 1013 in the first region 101 are all closed annular regions composed of line segments with different curvatures, and the three partitions 1021 to 1023 in the second region 102 are all closed annular regions composed of line segments with different curvatures. Starting from the center point of the optical film 101a, the three partitions 1011 to 1013 in the first region 101 and the three partitions 1021 to 1023 in the second region 102 are alternately arranged sequentially, and the second region 102 is directly adjacent to the first region 101, that is, there is no distance interval between the first region 101 and the second region 102.

[0077] Starting from the center region of the optical film 11a, a first region 101 is set, followed by a second region 102. Subsequently, the first region 101 and the second region 102 are set alternately. Specifically, in this embodiment, starting from the center point O1 of the optical film 11a, the first sub-region 1011, the third sub-region 1012, and the fifth sub-region 1013 are set alternately and adjacent to the three second sub-regions 1021, the fourth sub-region 1022, and the sixth sub-region 1023.

[0078] In other embodiments, the second region 102 is set starting from the center region of the optical film 11a, followed by the first region 101, and then the second region 102 and the first region 102 are set alternately in sequence. That is to say, the order in which the first region 101 and the second region 102 start from the center position is not limited by the figure shown, and can be set according to actual needs.

[0079] Please see Figure 4 As shown in the second embodiment of this application Figure 2 A schematic diagram of the pattern shape of the optical film 11b shown.

[0080] Figure 4As shown, the first region 101 is a closed annular region composed of straight line segments, and the second region 102 is a closed square region composed of straight line segments. The first region 101 can be a closed region composed of multiple closed straight line segments connected end to end, and the shape formed by the multiple closed straight line segments can be a square or the like. Correspondingly, the second region 102 can be a closed region composed of multiple closed straight line segments connected end to end, and the shape formed by the multiple closed straight line segments can be a square or the like.

[0081] Please see Figure 5 As shown in the third embodiment of this application Figure 2 A schematic diagram of the pattern shape of the optical film 11c shown.

[0082] Figure 5 As shown, the first region 101 is composed of segmented curves with the same or different curvatures, and the second region is composed of segmented curves with the same or different curvatures. That is to say, the first region 101 and the second region 102 are not closed regions composed of curve segments that connect end to end. For example, the first region 101 and the second region 102 are both spiral shapes that gradually extend from the center point O1 of the optical film 11c to the edge.

[0083] In this embodiment, the optical diaphragm 11c includes two second regions 102. Each second region 102 is a spiral-shaped region that starts from the center point O1 and gradually increases along the radius of curvature (not shown) from two different curvatures, with the curvature gradually decreasing. Correspondingly, the optical diaphragm 11c includes two first regions 101. Each first region 101 is a spiral-shaped region that starts from the center point O1 and gradually increases along the radius of curvature from two different curvatures, with the curvature gradually decreasing.

[0084] The curvature and radius of curvature of the first region 102 and the second region 102 at the center point O1, as well as the rate of change of curvature and radius of curvature during the gradual change process, can all be set according to actual needs.

[0085] In one embodiment of this application, the optical film 11d includes at least two sub-regions, each sub-region including a pattern formed by a first region 101 and a second region 102. For example, Figure 6 As shown, the optical film 11d includes four sub-regions, each sub-region including a pattern formed by a first region 101 and a second region 102. Of course, in other embodiments of this application, the number of sub-regions may also be 2, 3, 5, 6, etc., and is not limited thereto.

[0086] Please see Figure 6 As shown in the fourth embodiment of this application Figure 2 A schematic diagram of the pattern shape of the optical film 11d shown.

[0087] like Figure 6 As shown, the four sub-regions can be composed of the first sub-region A1, the second sub-region A2, the third sub-region A3, and the fourth sub-region A4, and each of the four regions is a rectangle.

[0088] The patterns formed by the first region 101 and the second region 102 contained in the first sub-region A1, the second sub-region A2, the third sub-region A3 and the fourth sub-region A4 are the same.

[0089] For example, such as Figure 6 As shown, in each of the first sub-region A1, the second sub-region A2, the third sub-region A3, and the fourth sub-region A4, the first region 101 and the second region 102 contained therein are both closed rings.

[0090] Or, such as Figure 7 As shown, in each of the first sub-region A1, the second sub-region A2, the third sub-region A3, and the fourth sub-region A4, the first region 101 and the second region 102 contained therein are both closed squares.

[0091] Or, such as Figure 8 As shown, within each of the first sub-region A1, the second sub-region A2, the third sub-region A3, and the fourth sub-region A4, the first region 101 and the second region 102 are both open spirals that gradually open from the center point.

[0092] Alternatively, the patterns formed by the first region 101 and the second region 102 contained in the first sub-region A1, the second sub-region A2, the third sub-region A3 and the fourth sub-region A4 may not be exactly the same.

[0093] Please see Figure 9 As shown in the fifth embodiment of this application Figure 2 A schematic diagram of the pattern shape of the optical film 11e shown. Figure 9 As shown, the four sub-regions can be composed of the first sub-region A1, the second sub-region A2, the third sub-region A3, and the fourth sub-region A4, and each of the four regions is a rectangle.

[0094] The patterns formed by the first region 101 and the second region 102 contained in the first sub-region A1, the second sub-region A2, the third sub-region A3 and the fourth sub-region A4 are not exactly the same.

[0095] For example, such as Figure 10As shown, the patterns contained in the first sub-region A1 and the fourth sub-region A4 are the same, that is, the patterns formed by the first region 101 and the second region 102 in the two regions are the same in shape. For example, the shapes of the first region 101 and the second region 102 contained in the two sub-regions are both open spirals that gradually open from the center point.

[0096] The second sub-region A2 contains both the first region 101 and the second region 102, which are closed squares.

[0097] The second sub-region A3 contains a closed ring shape consisting of both the first region 101 and the second region 102.

[0098] It should be noted that the order of the shapes of the first region 101 and the second region 102 set in the first sub-region A1, the second sub-region A2, the third sub-region A3, and the fourth sub-region A4 can be limited according to actual needs, and is not limited to the involute spiral, square, ring, and involute spiral shown in the figure. It can also be a square, an involute spiral, a ring, an involute spiral, or other orders. In addition, the same shape of the first region 101 and the second region 102 in the four sub-regions is not limited to an involute spiral. It can also be a closed square or a ring.

[0099] Please see Figure 11 , Figure 11 As in the sixth embodiment of this application Figure 1 The diagram shows a cross-sectional view of the electronic terminal 200 along line II.

[0100] like Figure 11 As shown, in the electronic terminal 100, the display screen DS and the optical film 11 and image sensor 13 in the fingerprint recognition device 20 are stacked sequentially from top to bottom along the first direction F1. At the same time, the fingerprint recognition device also includes a first light source 14, which is set at a preset distance from the image sensor 13 in the horizontal direction, for emitting light along the first direction F1 toward the optical film 11 and the finger.

[0101] The display screen DS is used to emit light and display images. In this embodiment, the display screen DS can be a liquid crystal display or an organic light-emitting diode (OLED) display.

[0102] When the display screen DS displays an image, it emits light. The light emitted by the display screen DS can illuminate the finger. The light is reflected by the finger and enters the optical film 11. The light entering the optical film 11 is patterned and then transmitted to the image sensor 13. The image sensor 13 obtains the image of the finger by detecting the light provided by the optical film 11.

[0103] Additionally, the first light source 14 provides auxiliary light, which shines on the finger through the optical film 11 and is then reflected by the finger into the optical film 11. In this embodiment, the first light source 14 can be a light-emitting diode (LED). Therefore, even when the display screen DS does not emit light to display an image, or when the provided light is insufficient, or when the ambient light around the display screen DS is insufficient, the first light source 14 can still provide and emit light to the finger for reflection. This allows the optical film 11 and the image sensor 13 to identify the finger image by detecting the light reflected from the finger, effectively improving the recognition efficiency of the fingerprint recognition device 20 and enhancing its application scenarios and ease of use.

[0104] In this embodiment, Figure 11 The structure of the optical film 11 in Figure 2 The shape, structure, material, and working principle of the optical film 11 shown are the same, and will not be described again in this embodiment.

[0105] against Figures 3-11 In the fingerprint module 10 shown, the image sensor 13 repeatedly acquires light signals provided by the optical film 11 at a preset frequency and converts them into multiple sets of electrical signals. That is, it acquires the fingerprint of the current finger multiple times and converts it into multiple sets of electrical signals. Then, it processes the above-mentioned multiple sets of electrical signals to obtain a fingerprint image. The processing of the above-mentioned electrical signals includes signal superposition, encoding, noise reduction, signal enhancement, and reverse encoding.

[0106] Specifically, the processing of the above-mentioned electrical signals includes:

[0107] Step 101: Select one set of electrical signals from multiple sets of electrical signals. The selected set of electrical signals contains the most feature points, so that it can more accurately represent the fingerprint compared to other sets of electrical signals. For example, it contains the most feature points of ridges, valleys and nodes (intersections) in the fingerprint.

[0108] Step 102: Superimpose the electrical signal corresponding to the preset virtual image onto a selected set of electrical signals. The preset virtual image is a virtual image with the same fixed pattern. In this embodiment, the preset virtual image is an image with the same shape as the pattern on the optical film 11. The virtual image can be described or represented by a function, and the electrical signal corresponding to the virtual image can be composed of multiple sub-electrical signals that satisfy a functional relationship.

[0109] Step 103: Extract and calculate the interference information from the selected set of electrical signals superimposed with a preset virtual image to obtain a fingerprint image. In this embodiment, for example, the calculation after the interference information is extracted includes performing a Fourier transform. Of course, the calculation after the interference information is extracted can also include other calculation processes according to actual needs, and is not limited to this example.

[0110] Please see Figure 12 , Figure 12 As shown in the seventh embodiment of this application Figure 1 The diagram shows a cross-sectional view of the electronic terminal 300 along line II.

[0111] In this embodiment, the fingerprint recognition device 30 in the electronic terminal 300 and Figure 2 The fingerprint recognition device 10 shown has a basically the same structure, the only difference being the material of the optical film 11f. Figures 3-10 Unlike other optical films, the optical film 11f can present different first patterns at different times. That is to say, the first pattern on the optical film 11f in this embodiment is dynamic and not just a fixed pattern shape. In this embodiment, the optical film 11f can present different light transmittance material compositions according to different voltage signals.

[0112] Specifically, such as Figure 12 As shown, the optical film 11f includes a first material layer ML1, a medium layer Me, and a second material layer ML2 stacked sequentially. A sealed cavity is formed between the first material layer ML1 and the second material layer ML2 to accommodate the medium layer Me, and the medium layer Me can be controlled by an electric field to have different transmittance and light flux.

[0113] In this embodiment, the dielectric layer Me is a liquid crystal material, which forms a liquid crystal grating under the control of an electric field. In other embodiments of this application, the dielectric layer Me may also be other materials whose transmittance and luminous flux change with the electric or magnetic field, and is not limited thereto.

[0114] In this embodiment, the first substrate layer ML1 is made of a material with filtering properties. That is, in addition to being used with the second substrate layer ML2 to form a sealed cavity to accommodate the medium layer Me, the first substrate layer ML1 is also used to perform the function of filtering light in a preset frequency band. For example, the first substrate layer ML1 can be made of an IR filter.

[0115] Please see Figure 13 , its is like Figure 12 The schematic diagram of the planar structure of the second substrate layer ML2 shown is as follows: Figure 13 As shown, a plurality of pixel areas Px are arranged in a matrix on the second substrate layer ML2. Each pixel area Px contains a driving circuit (not shown). These driving circuits generate electric fields of different intensities under different voltage control, and the different intensities of the electric fields can control the liquid crystal molecules in the dielectric layer Me to deflect at different angles. Therefore, by providing different voltages to the driving circuits within the pixel areas Px, different transmittances can be formed in different regions of the optical film 11f, and even different voltages can be provided to the driving circuits of pixel areas Px at different positions, thereby forming a transmittance pattern of a predetermined shape.

[0116] In this embodiment, the m-row * n-column pixel region Px contained in the optical film 11f can be represented as P11, P12, ..., P1n; ...; Pi1, Pi2, ..., Pin; Pn1, Pn2, ..., Pnm, where i is a natural number less than m.

[0117] It should be noted that the pixel region Px on the second substrate layer ML2 serves as a switching element for controlling the passage of light through the optical film 11f, and does not need to perform image display; that is to say, it is related to... Figure 1 The pixel units P shown are not the same in terms of the functions they perform when performing image display.

[0118] For example Figure 12 For example, in the case of the optical film 11f shown, a first voltage V1 is provided to the optical film 11f, and the first voltage V1 controls the light transmittance of the optical film 11f. Specifically, when the first voltage V1 and the first current I1 are different in different positions and different shapes of the optical film 11, different patterns can be formed.

[0119] Preferably, by applying different voltages to different regions of the optical film 11 at different time points, the optical film 11 can form different patterns at different times. In some optional embodiments, one or more of the phase, region size, or spacing between regions in different patterns may be different. In this embodiment, the first voltage V1 is a set of values ​​containing multiple voltages, the number of which is the same as the number of pixel regions Px.

[0120] For example, in the first time period t1, a first voltage set V1a containing a first set of values ​​is provided to the optical film 11f, which can present Figure 3 The closed annular pattern formed by the first region 101 and the second region 102 shown includes a set of values ​​that correspond to multiple voltage values ​​provided to the driving circuit of each pixel region Px. Corresponding to the set of pixel regions Px included in the optical film 11f, the first set of values ​​corresponding to the first voltage set V1a can be the voltages provided to the aforementioned pixel regions Px: {V11, V12, ..., V1n, ..., Vnm}.

[0121] During the second time period t2, a second voltage set V1b containing a second set of values ​​is provided to the optical film 11, which can present Figure 4 The closed square pattern formed by the first region 101 and the second region 102 shown can be represented by the second set of values ​​corresponding to the second voltage set V1b, which can be the voltage provided to the aforementioned pixel region Px: {V'11,V'12,….V'1n,……,V'nm}.

[0122] During the third time period t3, a third voltage set V1c containing a third numerical set is provided to the optical film 11, which can exhibit... Figure 5 The spiral pattern formed by the first region 101 and the second region 102 shown can be represented by the third set of values ​​corresponding to the third voltage set V1c, which can be the voltage provided to the aforementioned pixel region Px: {V”11,V”12,….V”1n,……,V”nm}.

[0123] During the fourth time period t4, a fourth voltage set V1d containing a fourth numerical set is provided to the optical film 11, which can present... Figure 6 The closed ring pattern formed by the first region 101 and the second region 102 contained in different sub-regions shown can be represented by the fourth set of values ​​corresponding to the fourth voltage set V1c, which can be the voltage provided to the aforementioned pixel region Px: {V”'11,V”'12,….V”'1n,……,V”'nm}.

[0124] Similarly, by adjusting the voltage values ​​of the set corresponding to the first voltage V1 for different pixel regions at different time periods, it is possible to display [the data] at different times. Figures 3-10 Or a pattern not shown.

[0125] In this embodiment, the number of pixel regions Px can be set according to the pattern accuracy formed by the optical film 11f. When the accuracy is high, the area of ​​each pixel region Px is smaller and the number of pixel regions Px per unit area (Pixels Per Inch, PPI) is more. Conversely, when the accuracy is low, the area of ​​each pixel region Px is larger and the number of pixel regions Px per unit area is less.

[0126] Please continue to refer to this as well. Figures 13-14 ,in, Figure 14 for Figure 12 The fingerprint recognition device 30 shown is a top view. Figure 13 As shown, the area surrounding the second substrate layer ML2 also includes multiple first conductive pads PA1. These first conductive pads PA1 are electrically connected to the driving circuit within each pixel region Px via conductive traces (not shown), and, in conjunction with the scanning circuit, apply multiple voltages from the first voltage V1 to the driving circuit within the pixel region Px. The scanning circuit is used to control different columns of pixel regions to receive the first voltage V1 at different time points according to a preset timing sequence. Figure 12 The optical film 11f shown can obtain different voltages from the outside for the driving circuits in the corresponding multiple pixel regions Px.

[0127] In this embodiment, for example, during the first time period t1, the specific way in which the multiple first conductive pads PA1 cooperate with the scanning circuit is as follows:

[0128] The scanning circuit is electrically connected to multiple columns of pixel regions Px through multiple wires. The scanning circuit scans the first column of pixel regions Px, the second column of pixel regions Px, ... the nth column of pixel regions Px according to a preset timing sequence.

[0129] Before the first column of pixel regions Px is scanned, multiple first conductive pads PA1 apply a first voltage V1 corresponding to the first column of pixel regions Px: V11, ..., Vi1, ..., Vm1. When the first column of pixel regions Px is scanned, the multiple first conductive pads PA1 apply the aforementioned voltages V11, ..., Vi1, ..., Vm1 to the driving circuit of the first column of pixel regions Px.

[0130] Multiple first conductive pads PA1 reload the first voltage V1: V12, ..., Vi2, ..., Vm2 corresponding to the second column pixel region Px after it is scanned and before it is scanned. When the first column pixel region Px is scanned, the multiple first conductive segments PA1 apply the aforementioned voltages V12, ..., Vi2, ..., Vm2 to the driving circuit of the second column pixel region Px.

[0131] This process continues until the scanning circuit scans the nth column pixel region Px. After the (n-1)th column pixel region Px is scanned but before the nth column pixel region Px is scanned, the multiple first conductive pads PA1 reload the first voltage V1 corresponding to the nth column pixel region Px: V1n, ..., Vin, ..., Vmn. When the nth column pixel region Px is scanned, the multiple first conductive segments PA1 apply the aforementioned voltages V1n, ..., Vin, ..., Vmn to the driving circuit of the nth column pixel region Px.

[0132] Therefore, in the first time period t1, the voltages in the first voltage set V1a: {V11,V12,….V1n,……,Vnm} are all loaded into the corresponding pixel region Px.

[0133] In addition, during the second time period t2, the third time period t3, and the fourth time period t4, the scanning circuit, in conjunction with multiple first conductive pads PA1, loads the voltage set corresponding to the first voltage into the pixel region Px.

[0134] Alternatively, in other embodiments of this application, the voltage set corresponding to the first voltage V1 can also be set with a corresponding number of first conductive pads PA1 corresponding to the number of pixel regions Px, and then all the voltages {V11,V12,….V1n,……,Vnm} in the first voltage set V1a can be loaded into the pixel region Px at the corresponding position at the same time.

[0135] Please continue reading. Figure 14 The image sensor 13 may also include multiple second conductive pads PA2. The image sensor 13 interacts with other functional modules through the second conductive pads PA2. For example, the image sensor 13 interacts with the image processor through the second conductive pads PA2.

[0136] In this embodiment, multiple second conductive pads PA2 and multiple first conductive pads PA1 are disposed on the same plane.

[0137] Please continue reading. Figure 12 and Figure 14 ,correspond Figure 14 Multiple second conductive pads PA2 and multiple first conductive pads PA1 are present in the middle. Figure 12 The support 15 shown also has multiple third conductive pads PA3. Multiple second conductive pads PA2 and multiple first conductive pads PA1 are electrically connected to the multiple third conductive pads PA3 through a wire bonding process. It can be understood that the multiple third conductive pads PA3 can also be electrically connected to a flexible printed circuit board (FPC). Through the flexible printed circuit board, the optical film 11f and the image sensor 13 can be connected to other functional circuits and perform electrical signal interaction.

[0138] The image sensor 13 obtains a fingerprint image by processing the electrical signals converted from multiple optical signals received at different times and under different patterns from the optical film 11f. The processing of the electrical signals includes signal superposition, encoding, denoising, signal enhancement, and inverse encoding.

[0139] Specifically, during the process of acquiring an image of a fingerprint of a finger, the optical film 11f presents different patterns at different times, with different phases between the different patterns.

[0140] In this embodiment, for example, the phase relationship between the light intensity through the optical film 11f and the pattern can be expressed as follows:

[0141] Where Lx represents the brightness of the light emitted through the optical film 11f, and r is the distance from the center point of the optical film 11f. β represents the phase of the current pattern of the optical film 11f, β represents the number of regions with different transmittance in the current pattern of the optical film 11f, and the spacing between two regions with the same transmittance in the edge region of the current pattern of the optical film 11f that is farthest from the center point.

[0142] For light emitted from an optical film 11f that displays different patterns at different times and is projected onto an image sensor 13, the processing of the electrical signals includes:

[0143] Step 201: For each pattern, collect multiple sets of electrical signals, select one set of electrical signals from the multiple sets of electrical signals. The selected set of electrical signals contains the most feature points, so that it can more accurately represent the fingerprint compared to other sets of electrical signals. For example, it contains the most feature points of ridges, valleys and nodes (intersections) in the fingerprint.

[0144] Step 202 involves superimposing a corresponding preset virtual image onto a selected set of electrical signals. The preset virtual image is a virtual image that is the same as the pattern presented by the optical film 11f at the current moment.

[0145] Step 203: For each pattern, the interference information obtained by superimposing a selected set of electrical signals with a preset virtual image is extracted and calculated to obtain a fingerprint image. Then, the fingerprint images corresponding to different patterns are superimposed again to obtain the fingerprint image corresponding to the current fingerprint. Information without phase components is considered noise and can be directly removed. The calculation method for information containing phase components includes Fourier transform calculation.

[0146] Please see Figure 15 , Figure 15 As in the eighth embodiment of this application Figure 1The schematic diagram shows a cross-sectional structure of the electronic terminal 400 along line II. In this embodiment, the electronic terminal 400 and... Figure 11 The electronic terminal 200 shown is basically the same, the only difference being that the fingerprint recognition device 10 in the electronic terminal 400 does not include an optical film 11, but instead uses a display screen DS. Figure 11 The optical film 11 in the electronic terminal 200 shown, that is, the display screen DS multiplexes the emitted light to display an image and emits patterned light to the finger and transmits the light reflected from the finger to the image sensor 13 to obtain a fingerprint image.

[0147] The electronic terminal 400 includes a display screen (DS) and a fingerprint recognition device 10. The fingerprint recognition device 10 further includes an image sensor 13, a support member 15, and a first circuit board 17. Specifically, as shown... Figure 15 As shown, in the electronic terminal 100, the display screen DS and the image sensor 13 in the fingerprint recognition device 20 are arranged sequentially from top to bottom along the first direction F1.

[0148] Specifically, the display screen DS includes a fifth surface DS1 and a sixth surface DS2 opposite to each other in the first direction F1. The fifth surface DS1 is used to receive the finger; that is, when the finger operates the mobile terminal 10, it is adjacent to or in direct contact with the fifth surface DS1 of the display screen DS. The sixth surface DS2 is adjacent to the optical film 11 than the fifth surface DS1.

[0149] In this process, the emission of light from the display screen DS to display an image and the emission of patterned light to the finger to obtain a fingerprint image are not simultaneous, but are performed in a time-division manner. For example, the electronic terminal 400 includes an image display state and a fingerprint acquisition state that are executed at different times. When the electronic terminal 400 is in the image display state, the display screen DS emits light according to the image data (Data) to display the image, and stops emitting light of the first pattern according to the received first voltage V1. When the electronic terminal 400 is in the fingerprint acquisition state, the display screen DS stops emitting light according to the image data (Data), and instead emits light of the first pattern according to the received first voltage V1. The light shines on the finger and transmits the light reflected from the finger to the image sensor 13 to obtain a fingerprint image.

[0150] On one hand, the display screen DS is used to emit light and display images. In this embodiment, the display screen DS can be a liquid crystal display or an organic light-emitting diode display (OLED). On the other hand, the display screen DS is provided with features such as... Figures 3-10The patterns shown, with different shapes, different emitted light intensities, and different color areas, transmit the patterned light emitted to the finger and the light reflected from the finger to the image sensor 13, thereby achieving... Figures 3-10 The optical film 11 shown performs the same effect as patterning light.

[0151] The support member 15 supports the image sensor 13. A first circuit board 17 is disposed adjacent to the support member 15 and electrically connected to the image sensor 13. The functional circuitry on the first circuit board 17 provides driving power and control signals to the image sensor 13, driving and controlling the image sensor 13 to convert optical signals into electrical signals, and transmitting the received electrical signals from the image sensor 13 to an image processor (not shown). This allows the image processor to amplify, filter, and process the electrical signals, and construct an image of the surface of a finger reflecting the light based on the processed electrical signals. In this embodiment, the first circuit board 17 can be a flexible circuit board and directly electrically connected to the image sensor 13. Alternatively, the first circuit board 17 and the image processor 13 can also be electrically connected via a board-to-board connector.

[0152] The image sensor 13 includes a third surface 131, which is opposite to the optical diaphragm 11, that is, the optical diaphragm 11 is disposed adjacent to the third surface 131 of the image sensor 13. The third surface 131 performs a third optical processing to collect light within a preset frequency band.

[0153] Please see Figure 16 This is one implementation method in this embodiment, such as... Figure 15 The diagram shown is a schematic representation of the pattern shape on the DS display screen. Figure 16 As shown, the patterned shape of the display screen DS is mainly composed of at least two regions 101 and 102 with different light intensities. That is, the patterned shape of the display screen DS can include two, three, or four regions with different light intensities, and the number of regions with different light intensities can be set according to actual needs. In this embodiment, the patterned shape of the display screen DS mainly consists of at least two regions 101 and 102 with different light intensities, which has the same effect as the at least two regions 101 and 102 with different light transmittance in the optical film 11, providing light of different intensities to the fingerprint sensor 13.

[0154] Among them, the light intensity of two different areas 101 and 102 in the display screen DS is as follows: Figure 17 As shown, where, Figure 17 For example Figure 16 The diagram shows the light intensity distribution in two regions 101 and 102 with different light intensities on the display screen DS. Figure 17As shown, the light intensity of the light emitted from the first region 101 is 85%-95%, and the light intensity of the light emitted from the second region 102 is 0%-5%.

[0155] The relationship between the intensity of the emitted light from the first region 101 and the second region 102 and the distance O1 from the center is as follows: taking the position of the center point O as the initial phase, the transmittance variation curve of the initial center brightness is designed according to the cosine law, and the specific correspondence can be expressed by the following formula:

[0156] Lx=0.5*(1+COS(100*r2^2+φ)).

[0157] Therefore, corresponding to the first region 101, as the distance r from the center point O1 gradually increases, the light intensity of the emitted light in each first region 101 gradually decreases, and thus the light intensity Lx incident on the image sensor 13 through each first region 101 gradually decreases.

[0158] Corresponding to the second region 102, as the distance r from the center point O1 gradually increases, the light intensity of the emitted light in each second region 102 gradually increases, and thus the light intensity Lx incident on the image sensor 13 through each second region 102 gradually increases.

[0159] Therefore, by setting the areas on the display screen DS that emit light of different intensities, the intensity of the light incident on the image sensor 13 is diversified, thereby enabling the image sensor 13 to have a sufficiently diverse range of light signals to perform conversion, ultimately improving the quality of the electrical signals obtained by the image sensor 13 after converting the light signals and the image composed of the electrical signals.

[0160] In other embodiments of this application, the transmittance of each first region 101 can also be kept to a single value, for example, the transmittance of each first region 101 is 95%. The transmittance of each second region 102 can also be kept to a single value, for example, the transmittance of each second region 102 is 5%.

[0161] The above description is a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A fingerprint recognition device, characterized by, The optical film and the image sensor are arranged along a first direction and spaced apart by a first distance, The optical film includes at least two sub-regions, each of which includes a first region and a second region, the first region and the second region have different light transmittances, the first region and the second region form a first pattern, when the optical film receives light reflected from a first object, the light is converted into an optical image having the first pattern and transmitted to the image sensor, wherein the optical film includes a plurality of conductive electrodes for receiving a first voltage, the first voltage controls the light transmittances of different regions of the optical film to form different patterns, wherein the optical film loads different voltages in different regions at different time points, and the phase, region size and region spacing of the patterns formed by the optical film at different time points are different to form a dynamically changing first pattern, the optical signal of the first pattern obtained through the optical film superimposes the intensity of light in a preset frequency band, in at least one sub-region, the first region and the second region are alternately arranged from the center of the sub-region, the first region and the second region are alternately arranged, and the first region and the second region are involute spiral shapes, and for the first region with a light transmittance in a first range, the light transmittance in each light transmittance region gradually decreases as the distance from the center position gradually increases, and for the second region with a light transmittance in a second range, the light transmittance in each light transmittance region gradually increases as the distance from the center position gradually increases, the first range is greater than the second range; The image sensor is configured to receive an optical signal in the optical image and convert the optical signal into an electrical signal, and the electrical signal is used to construct an image of a surface of the first object reflecting the light.

2. The fingerprint recognition apparatus according to claim 1, characterized in that, The optical film includes at least two sub-regions, the at least two regions include a first sub-region and a second sub-region, The first region and the second region in the first sub-region are both closed squares composed of curves or straight lines, and the first region and the second region in the second sub-region are closed annular shapes composed of curves or straight lines; or The first region and the second region in the first sub-region are both closed squares or annular shapes composed of curves or straight lines, and the first region and the second region in the second sub-region are involute spiral shapes composed of segmented curves with the same curvature or different curvatures.

3. The fingerprint recognition apparatus according to claim 1, wherein The optical film includes at least two sub-regions, the at least two regions include a first sub-region, a second sub-region and a third sub-region; The first region and the second region in the first sub-region are both closed squares composed of curves or straight lines; The first region and the second region in the second sub-region are closed annular shapes composed of curves or straight lines; The first region and the second region in the third sub-region are involute spiral shapes composed of segmented curves with the same curvature or different curvatures.

4. The fingerprint recognition apparatus according to any one of claims 1 to 3, wherein The first distance is less than 0.5 millimeters.

5. The fingerprint recognition apparatus according to claim 4, wherein The optical film has a thickness along the first direction less than 500 microns.

6. The fingerprint recognition apparatus according to claim 5, wherein The optical film is spaced apart from the first object along the first direction by a second distance in a range of 0.05-5 millimeters.

7. The device according to any of claims 1-3, characterized in that The optical film is made of resin or glass, or a combination of one or more of high light transmittance, high light transmittance and low reflectivity, high light transmittance and high reflectivity.

8. The fingerprint recognition apparatus according to claim 7, wherein The fingerprint recognition device further comprises a first light source configured to provide auxiliary light, the auxiliary light being transmitted to the first object through the optical film, the first light source and the image sensor being disposed on a surface of a support configured to support the first light source and the image sensor; or The first light source is a display screen configured to display images and disposed on a side of the optical film away from the image sensor, the auxiliary light provided by the display screen when displaying images being directly transmitted to the first object.

9. The fingerprint recognition apparatus according to claim 8, wherein, A distance between the first surface of the optical film and the surface of the support along the first direction is less than 1 millimeter.

10. The fingerprint recognition apparatus according to claim 1, wherein The optical film comprises a first surface and a second surface oppositely disposed along the first direction, the first surface being farther away from the image sensor than the second surface, and the first surface being processed to have a first optical property to collect light in a preset frequency range.

11. The fingerprint recognition apparatus according to claim 10, wherein The optical film comprises a first surface and a second surface oppositely disposed along the first direction, the first surface being farther away from the image sensor than the second surface, and the second surface being processed to have a second optical property to collect light in a preset frequency range.

12. The fingerprint identification device according to claim 10 or 11, characterized in that, The image sensor comprises a third surface facing the optical film, the third surface being processed to have a third optical property to collect light in a preset frequency range.

13. The fingerprint recognition apparatus according to claim 1, wherein The optical film comprises a first substrate layer, a medium layer and a second substrate layer stacked in sequence, and a cavity is formed between the first substrate layer and the second substrate layer to accommodate the medium layer, The second substrate layer is provided with a plurality of pixel regions arranged in a matrix and a plurality of conductive pads, each pixel region being provided with a driving circuit electrically connected to the conductive pads and receiving the first voltage through the conductive pads, the driving circuit forming an electric field of different intensity under different first voltage control; The medium layer has different light transmittances under different intensity electric fields; The first pattern of different light transmittances is formed when different pixel regions receive different driving voltages.

14. The fingerprint recognition apparatus according to claim 13, wherein, The first substrate layer is further configured to filter out light in a preset frequency range and wavelength.

15. The fingerprint recognition apparatus according to claim 14, wherein, Different first voltages are provided to a plurality of pixel units in the pixel region at different time periods and the pattern of any one of claims 7-13 is presented at different times.

16. An electronic terminal, characterized in that The display screen is arranged on the side of the optical film away from the image sensor along the first direction, and the display screen is spaced apart from the optical film by a third distance in the range of 0.005-5 mm, and the light reflected from the first object is transmitted to the optical film through the display screen.

17. The electronic terminal of claim 16, wherein, The display screen replaces the optical film, and the display screen comprises the pattern according to any one of claims 2-7.

Images