Filter film and preparation method, filter, fingerprint recognition module and recognition method

Abstract

The present application provides a filter film and a preparation method, a filter, a fingerprint recognition module and a recognition method, which are applied to the field of fingerprint recognition, wherein the filter film includes: an infrared cut-off film, a red light filter unit is provided in the infrared cut-off film, and the red light filter unit is used to pass part or all of the red light signal; wherein the red light filter unit is obtained by adjusting the thickness of the infrared cut-off film. In the above scheme, the area corresponding to the red light filter unit on the infrared cut-off film is adjusted by adjusting the thickness of the infrared cut-off film so that the red light signal can pass through. Therefore, when the filter film provided by the embodiment of the present application is adopted, on the basis of adopting the infrared cut-off film to achieve sunlight protection, the passing red light signal can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with sunlight protection effect for true and false fingerprints.

Description

Technical Field

[0001] The present application relates to the field of fingerprint recognition, and more specifically, to a filter film and a preparation method thereof, a filter, a fingerprint recognition module and a recognition method. Background Art

[0002] With the rapid development of the electronics industry, the functions of electronic devices are becoming more and more powerful. In order to improve the intelligence of electronic devices, fingerprint recognition technology has been widely used in electronic devices in recent years. Specifically, the fingerprint recognition device on the electronic device usually collects the optical signal carrying the fingerprint information to realize the fingerprint unlocking function.

[0003] In actual applications, an infrared cutoff film (IR-Cut) is usually set on the fingerprint recognition device. Since the cutoff wavelength of the infrared cutoff film is generally less than 605 nanometers (nm), it can achieve the purpose of sunlight protection. The fingerprint recognition device with sunlight protection effect in the prior art has poor anti-counterfeiting performance against real and fake fingerprints. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a filter film and a preparation method, a filter, a fingerprint recognition module and a recognition method, so as to solve the technical problem that the fingerprint recognition device with anti-sunlight effect has poor anti-counterfeiting performance against real and fake fingerprints.

[0005] In the first aspect, the embodiment of the present application provides a filter film, including: an infrared cut-off film, in which a red light filter unit is provided, and the red light filter unit is used to pass part or all of the red light signal; wherein the red light filter unit is obtained by adjusting the thickness of the infrared cut-off film. In the above scheme, the thickness of the infrared cut-off film is adjusted so that the area corresponding to the red light filter unit on the infrared cut-off film can pass the red light signal. Therefore, when the filter film provided by the embodiment of the present application is adopted, on the basis of adopting the infrared cut-off film to achieve sunlight protection, the passing red light signal can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with sunlight protection effect for true and false fingerprints.

[0006] In an optional embodiment, the infrared cut-off film includes multiple sub-film layers, wherein the film layer of the red light filter unit is a partial sub-film layer among the multiple sub-film layers, and the partial sub-film layer allows part or all of the red light signal to pass through. In the above scheme, the anti-sunlight effect of the infrared cut-off film can be achieved by setting multiple sub-film layers. On this basis, the film layer of the red light filter unit is a partial sub-film layer therein. Since the number of layers of the red light filter unit is smaller than the number of layers of the infrared cut-off film, more red light signals can be passed through, so that the passed red light signal can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with anti-sunlight effect against true and false fingerprints.

[0007] In an optional embodiment, the red light filtering unit is obtained by removing redundant sub-film layers in the multi-layer sub-film layers, wherein the redundant sub-film layers are sub-film layers in the multi-layer sub-film layers except for the partial sub-film layers. In the above scheme, after the multi-layer sub-film layers are set to realize the infrared cut-off film, the remaining partial sub-film layers can transmit more red light signals by removing a portion of the redundant sub-film layers in the multi-layer sub-film layers. Therefore, since only a portion of the sub-film layers in the multi-layer sub-film layers need to be removed, the process is simpler and less consumables are required compared with the scheme of adding red light filtering materials in the prior art.

[0008] In an optional embodiment, the red light filtering unit is grooves distributed in the infrared cut-off film, wherein the grooves allow part or all of the red light signal to pass through.

[0009] In an optional embodiment, the red light filter unit is also used to pass other light signals adjacent to the wavelength band of the red light signal. In the above scheme, according to the different thicknesses of the set red light filter unit, it can also pass other light signals adjacent to the wavelength band of the red light signal, so that the difficulty of the process can be further reduced on the basis of ensuring the anti-counterfeiting effect according to the actual situation.

[0010] In an optional embodiment, the filter film is further provided with filter units for light of other colors except the red light, for passing light signals of other colors. In the above scheme, the filter film can also be provided with filter units corresponding to light of other colors, so as to further improve the anti-counterfeiting performance of the fingerprint recognition device against real and fake fingerprints.

[0011] In an optional embodiment, the light filtering unit for other colors is obtained by filling a light filtering material in a filling unit included in the infrared cutting film; or, the light filtering unit for other colors is arranged on the outer surface of the infrared cutting film.

[0012] In an optional embodiment, the filling unit includes a filling groove provided on the upper surface of the infrared cut-off film; and / or the filling unit includes a filling hole provided on the lower surface of the infrared cut-off film.

[0013] In an optional embodiment, part or all of the filter units are arranged in the edge area of ​​the infrared cut-off film.

[0014] In an optional embodiment, the edge region includes four sub-regions; the four sub-regions are symmetrically and adjacently arranged at four right angles of the infrared cut-off film.

[0015] In a second aspect, an embodiment of the present application provides a filter, comprising: a filter film as described in any of the aforementioned embodiments; and a substrate, wherein the filter film is arranged on the upper surface of the substrate.

[0016] In an optional embodiment, the filter further includes a filter unit for light of other colors except the red light, and the filter unit is arranged on a side of the substrate away from the filter film.

[0017] In a third aspect, an embodiment of the present application provides a fingerprint recognition module, comprising: a filter film as described in any of the above embodiments; a sensor, comprising a photosensitive pixel array, wherein the photosensitive pixel array comprises a plurality of photosensitive units; wherein the filter film is disposed above the sensor, and the filter units are disposed corresponding to the photosensitive units in the sensor. In the above solution, the filter film can be disposed above the sensor, and since the thickness of the entire fingerprint recognition module is relatively small, an ultra-thin fingerprint recognition device can be realized.

[0018] In a fourth aspect, an embodiment of the present application provides a fingerprint recognition module, comprising: a filter as described in the above embodiment; a sensor, comprising a photosensitive pixel array, wherein the photosensitive pixel array comprises a plurality of photosensitive units; wherein the filter is arranged above the sensor, and the photosensitive units are arranged corresponding to the photosensitive units in the sensor. In the above scheme, the filter can be arranged above the sensor, and the filter film in the filter can be arranged above the substrate, so that a lens-type fingerprint recognition device can be realized.

[0019] In a fifth aspect, an embodiment of the present application provides a method for preparing a filter film, comprising: preparing an infrared cut-off film on the upper surface of a target substrate; adjusting the thickness of a first target area in the infrared cut-off film to obtain a red light filter unit; wherein the red light filter unit allows part or all of the red light signal to pass through. In the above scheme, after preparing the infrared cut-off film on the target substrate, the red light filter unit can be obtained by adjusting the thickness of a part of the area in the infrared cut-off film. Therefore, when the filter film provided by the embodiment of the present application is adopted, on the basis of adopting the infrared cut-off film to achieve sunlight protection, the passing red light signal can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with sunlight protection effect for true and false fingerprints. In addition, since only the thickness of the infrared cut-off film needs to be adjusted, the process is simpler and less consumables are required compared with the solution of adding red light filter material in the prior art.

[0020] In an optional embodiment, adjusting the thickness of the first target area in the infrared cut-off film to obtain the red light filtering unit includes: performing a thinning process on the first target area in the infrared cut-off film to obtain the red light filtering unit.

[0021] In an optional embodiment, the preparing an infrared cut-off film on the upper surface of the target substrate comprises: preparing a plurality of sub-film layers on the upper surface of the target substrate; the thinning treatment of the first target area in the infrared cut-off film to obtain the red light filtering unit comprises: removing redundant sub-film layers in the first target area in the plurality of sub-film layers to obtain the red light filtering unit.

[0022] In an optional embodiment, the target substrate is a sensor, the sensor includes a photosensitive pixel array, the photosensitive pixel array includes a plurality of photosensitive units; the first target area is an area corresponding to one or more photosensitive units. In the above scheme, an infrared cutoff film can be prepared on the upper surface of the sensor. Since the thickness of the prepared filter film is small, an ultra-thin fingerprint recognition device can be realized based on the filter film.

[0023] In an optional embodiment, the target substrate is a substrate, the substrate is arranged above the sensor, the sensor includes a photosensitive pixel array, the photosensitive pixel array includes a plurality of photosensitive units; the first target area is an area corresponding to one or more photosensitive units. In the above scheme, the infrared cut-off film can be prepared on the upper surface of the substrate, the substrate is located above the sensor, so a lens-type fingerprint recognition device can be realized based on the filter.

[0024] In an optional embodiment, before preparing the infrared cut-off film on the upper surface of the target substrate, the method further includes: adding a filter material on the upper surface of the substrate to obtain filter units for light of other colors except red light. In the above scheme, filter units corresponding to other colors of light can also be provided in the filter film to further improve the anti-counterfeiting performance of the fingerprint recognition device against real and fake fingerprints.

[0025] In an optional embodiment, before preparing the infrared cut-off film on the upper surface of the target substrate, the method further includes: adding a filter material on the upper surface of the sensor to obtain filter units for light of other colors except red light. In the above scheme, filter units corresponding to other colors of light can also be provided in the filter film to further improve the anti-counterfeiting performance of the fingerprint recognition device against real and fake fingerprints.

[0026] In an optional embodiment, after adjusting the thickness of the first target area in the infrared cut-off film to obtain a filter unit for red light, the method further includes: reducing the thickness of the second target area in the infrared cut-off film to obtain a filling groove; wherein the second target area is an area corresponding to one or more photosensitive units; and adding a filter material to the filling groove to obtain a filter unit for light of other colors except red light. In the above scheme, filter units corresponding to light of other colors can also be provided in the filter film to further improve the anti-counterfeiting performance of the fingerprint recognition device against true and false fingerprints.

[0027] In an optional embodiment, after adjusting the thickness of the first target area in the infrared cut-off film to obtain the red light filter unit, the method further includes: adding a filter material to the upper surface of the infrared cut-off film to obtain a filter unit for other colors of light except red light. In the above scheme, the filter film can also be provided with filter units corresponding to other colors of light, further improving the anti-counterfeiting performance of the fingerprint recognition device against real and fake fingerprints.

[0028] In an optional embodiment, the adding of the filter material includes: coating the filter material by material addition, wherein the material addition method includes spraying or spot coating. In the above scheme, by coating the filter material by low-precision material addition, the difficulty of the process is reduced and consumables are reduced.

[0029] In a sixth aspect, the embodiments of the present application provide a fingerprint anti-counterfeiting identification method, comprising: obtaining a light signal received by a photosensitive unit, wherein the light signal is received by the photosensitive unit after passing through the filter unit in the filter film as described in any of the above embodiments or the filter unit in the filter sheet as described in the above embodiments; and performing authenticity identification of the fingerprint according to the light signal. In the above scheme, when the filter film or filter sheet provided by the embodiments of the present application is used, on the basis of using an infrared cut-off film to achieve sunlight protection, the red light signal passing through can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint identification device with sunlight protection effect for true and false fingerprints.

[0030] In a seventh aspect, an embodiment of the present application provides an electronic device, comprising a display panel and a fingerprint recognition module as described in the above embodiment; the fingerprint recognition module is arranged below the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of the structure of a filter film provided in an embodiment of the present application;

[0033] Figure 2 A schematic diagram of the internal structure of a filter film provided in an embodiment of the present application;

[0034] Figure 3A schematic diagram of a configuration method of a first type of filter unit for other color lights in a filter film provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of the arrangement of the second other color light filter unit in the filter film provided in an embodiment of the present application;

[0036] Figure 5 A schematic diagram of the internal structure of the arrangement of the second light filter unit for other color lights in the filter film provided in an embodiment of the present application;

[0037] Figure 6 A schematic diagram of a configuration of a third type of filter unit for other color light in the filter film provided in an embodiment of the present application;

[0038] Figure 7 A schematic diagram of the arrangement of filter units for multiple other colors of light in the filter film provided in an embodiment of the present application;

[0039] Figure 8 A schematic diagram of the arrangement of filter units for multiple other colors of light in the filter film provided in an embodiment of the present application;

[0040] Fig. 9 A schematic diagram of a region where a filter unit is located on an infrared cut-off film provided in an embodiment of the present application;

[0041] Fig.10 A schematic diagram of the structure of a filter provided in an embodiment of the present application;

[0042] Fig.11 A schematic diagram of a configuration of a fourth type of filter unit for other color light in the filter provided in an embodiment of the present application;

[0043] Fig.12 A schematic diagram of the structure of a fingerprint recognition module provided in an embodiment of the present application;

[0044] Fig.13 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0045] Fig.14 A schematic diagram of the structure of another fingerprint recognition module provided in an embodiment of the present application;

[0046] Fig.15 A schematic diagram of the structure of another electronic device provided in an embodiment of the present application;

[0047] Fig.16 A flow chart of a method for preparing a filter film provided in an embodiment of the present application;

[0048] Fig.17A flowchart of a fingerprint anti-counterfeiting identification method provided in an embodiment of the present application.

[0049] Icons: 100-filter film; 110-infrared cut-off film; 111-red light filter unit; 112-other color light filter units; 112a-blue light filter unit; 112b-green light filter unit; 200-filter; 210-substrate; 300-fingerprint recognition module; 310-sensor; 400-electronic device; 410-display panel; 420-first light-transmitting layer; 430-bonding light-transmitting layer; 440-optical signal guiding structure layer; 441-aperture layer; 442-aperture hole; 443-lens array layer; 444-microlens structure; 450-finger; 500-fingerprint recognition module; 510-sensor; 600-electronic device; 620-lens; 621-lens barrel; 622-lens. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0051] Please refer to Figure 1 , Figure 1 The structure diagram of a filter film provided in an embodiment of the present application is shown in FIG. 1 , wherein the filter film 100 may include an infrared cut-off film 110 . A red light filter unit 111 is provided in the infrared cut-off film 110 for passing part or all of the red light signal, and the red light filter unit 111 is obtained by adjusting the thickness of the infrared cut-off film 110 .

[0052] Specifically, the infrared cut-off film 110 is an optical film used to prevent the transmission of infrared light signals. The cut-off wavelength of the infrared cut-off film 110 is generally 605nm, the wavelength of the infrared light signal is generally between 760nm-1mm, the wavelength of sunlight is generally between 400nm-760nm, and the wavelength of red light is generally between 620nm-760nm. Therefore, red light signals and infrared light signals with wavelengths greater than 606nm are difficult to pass through the infrared cut-off film, and the best signals to distinguish true and false fingerprints are red light signals and infrared light signals. In other words, although the infrared cut-off film 110 can achieve the purpose of preventing sunlight, that is, it can prevent infrared interference with fingerprint recognition, but the anti-counterfeiting performance against true and false fingerprints is poor.

[0053] Based on this, the embodiment of the present application adjusts the thickness of certain areas of the infrared cut-off film 110 to obtain the red light filter unit 111, so that part or all of the red light signal can pass through the red light filter unit 111, so as to identify the true and false fingerprints according to the part or all of the red light signal that passes through. Therefore, when the filter film 100 provided by the embodiment of the present application is used, on the basis of using the infrared cut-off film 110 to achieve sunlight protection, the passing red light signal can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with sunlight protection effect for true and false fingerprints.

[0054] It is understandable that part or all of the red light signal refers to a red light signal of a partial band or a red light signal of the entire band in the red light signal, for example: a red light signal with a wavelength range of 620nm-700nm; or, a red light signal with a wavelength range of 620nm-760nm.

[0055] As an implementation method, please refer to Figure 2 , Figure 2 A schematic diagram of the internal structure of a filter film provided in an embodiment of the present application shows that the infrared cut-off film 110 may include a plurality of sub-film layers, wherein the film layer of the red light filter unit 111 is a partial sub-film layer in the plurality of sub-film layers, and the partial sub-film layer allows part or all of the red light signal to pass through.

[0056] Among them, the number of layers of the multi-layer sub-film layer and the number of layers of the partial sub-film layer can be determined in advance by the preparation personnel. In the process of preparing the filter film 100 provided in the embodiment of the present application, the multi-layer sub-film layers can be plated in sequence according to the determined number of layers. Then, the redundant sub-film layers in certain areas of the multi-layer sub-film layers (i.e., the sub-film layers other than the partial sub-film layers in the multi-layer sub-film layers) can be removed to obtain the red light filter unit 111. In other words, the red light filter unit 111 can be obtained by removing the redundant sub-film layers in the multi-layer sub-film layers. Therefore, since only a part of the sub-film layers in the multi-layer sub-film layers need to be removed, compared with the solution of adding red light filter materials in the prior art, the process of the filter film 100 provided in the embodiment of the present application is simpler and uses less consumables.

[0057] Understandably, Figure 2 The number of layers of the multi-layer sub-film layers and the number of layers of the partial sub-film layers shown are examples, and those skilled in the art should adjust the number of layers of the multi-layer sub-film layers and the number of layers of the partial sub-film layers according to actual conditions. In addition, the embodiment of the present application does not specifically limit the specific film layer components of the infrared cut-off film 110, and those skilled in the art can also make appropriate adjustments according to actual conditions.

[0058] For example, the infrared cut-off film 110 may include silicon oxide and titanium oxide, and the silicon oxide and titanium oxide are arranged alternately, that is, a layer of silicon oxide, a layer of titanium oxide, a layer of silicon oxide, a layer of titanium oxide, and so on. The number of layers of the infrared cut-off film 110 may be 70, and the number of layers of the red light filter unit 111 may be 45. Therefore, 70 sub-film layers may be plated in the order of a layer of silicon oxide and a layer of titanium oxide to obtain the infrared cut-off film 110; then, 25 redundant sub-film layers in certain areas of the 70 sub-film layers are removed, and the obtained 45 partial sub-film layers are the red light filter unit 111.

[0059] In the embodiment of the present application, the method of removing the redundant sub-membrane layer may be to perform a thinning process.

[0060] After removing the redundant sub-film layer on the infrared cut-off film 110, as shown in FIG. Figure 2 As shown, it can be seen that the red light filter unit 111 is a groove distributed in the infrared cut-off film 110, wherein the groove allows part or all of the red light signal to pass through.

[0061] It can be understood that since the number of partial sub-membrane layers corresponding to the red light filtering unit 111 is related to the wavelength band of the transmitted light signal, when the accuracy of the equipment for removing excess sub-membrane layers is low or the preparation personnel have low accuracy in determining the number of excess sub-membrane layers, the number of partial sub-membrane layers corresponding to the red light filtering unit may be less than or greater than the number of layers that can just pass the red light signal band.

[0062] In this case, the red light filter unit 111 is also used to pass other light signals adjacent to the wavelength band of the red light signal. Therefore, according to the different thicknesses of the red light filter unit 111, it can also pass other light signals adjacent to the wavelength band of the red light signal, so that the difficulty of the process can be further reduced on the basis of ensuring the anti-counterfeiting effect according to the actual situation.

[0063] In the above scheme, the anti-sunlight effect of the infrared cutoff film 110 can be achieved by setting a multi-layer sub-film layer. On this basis, the film layer of the red light filter unit 111 is a part of the sub-film layer. Since the number of layers of the red light filter unit 111 is smaller than the number of layers of the infrared cutoff film 110, more red light signals can be transmitted, so that the passed red light signals can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with anti-sunlight effect against true and false fingerprints.

[0064] Furthermore, the filter film 100 provided in the embodiment of the present application may also be provided with a filter unit 112 for light of other colors except red light.

[0065] Specifically, in order to further improve the anti-counterfeiting performance of the fingerprint recognition device for real and fake fingerprints, other color light filter units may be provided in the filter film 100, for example, a blue light filter unit 112a, a green light filter unit 112b, a yellow light filter unit, etc. Each other color light filter unit is used to pass the corresponding color light, for example, the blue light filter unit 112a is used to pass the blue light signal.

[0066] In the embodiment of the present application, three setting methods are provided for a filter unit for light of other colors. The three setting methods for the filter unit for light of other colors are introduced in turn below.

[0067] For the first one, please refer to Figure 3 , Figure 3 Schematic diagram of the arrangement of the first other color light filter unit in the filter film provided in the embodiment of the present application. The other color light filter unit 112 is obtained by filling the filter material in the filling unit included in the infrared cut-off film 110, and the filling unit includes a filling groove arranged on the upper surface of the infrared cut-off film 110.

[0068] Among them, Figure 3 As shown, similar to the red light filter unit 111, the thickness of certain areas of the infrared cutoff film 110 can be adjusted to form a filling groove on the infrared cutoff film 110, and the filter material can be filled in the filling groove to obtain filter units for other colors of light.

[0069] It is understandable that the height of the upper surface of the filter unit for other color lights may be higher than the height of the upper surface of the infrared cut-off film 110 (eg Figure 3 ); The height of the upper surface of the filter unit for other color lights may also be lower than the height of the upper surface of the infrared cut-off film 110.

[0070] For the second type, please refer to Figure 4 , Figure 4 A schematic diagram of the arrangement of the second other color light filter unit in the filter film provided in the embodiment of the present application. The other color light filter unit 112 is obtained by filling the filter material in the filling unit included in the infrared cut-off film 110, and the filling unit includes a filling hole arranged on the lower surface of the infrared cut-off film 110.

[0071] Among them, Figure 4 As shown, a filling hole may be formed on the lower surface of the infrared cut-off film 110 , and a filter unit for light of other colors may be obtained by filling the filling hole with a filter material.

[0072] It should be noted that Figure 4The filling holes are not formed by adjusting the thickness of the infrared cut-off film 110. Usually, the lower surface of the infrared cut-off film 110 is in contact with other objects (e.g., sensors, substrate 210, etc.). Therefore, when preparing the filter film 100, filter materials can be first added to certain areas of the upper surface of other objects to form filter units of other color lights; and then the infrared cut-off film 110 is plated layer by layer on other areas of the upper surface of the object and the filter units of other color lights.

[0073] Since some areas on the lower surface of the infrared cut-off film 110 are provided with light filtering units of other colors, the height of the corresponding area on the upper surface of the infrared cut-off film 110 will be higher than that of other areas, such as Figure 5 shown.

[0074] For the third type, please refer to Figure 6 , Figure 6 The schematic diagram of the arrangement of the third type of other color light filter unit in the filter film provided by the embodiment of the present application is as follows: The other color light filter unit 112 is arranged on the outer surface of the infrared cut-off film 110 .

[0075] Above Figure 3-Figure 6 In the figure, only one other color filter unit is provided on the filter film 100. It can be understood that when multiple other color filter units are provided on the filter film 100, one, two or three of the above three configurations can be adopted. For example, assuming that a blue light filter unit 112a and a green light filter unit 112b are provided on the filter film 100, the blue light filter unit 112a and the green light filter unit 112b can both adopt the third configuration (such as Figure 7 ), or the blue light filter unit 112a adopts the second setting mode and the green light filter unit 112b adopts the third setting mode (such as Figure 8 ).

[0076] Of course, for the same other color light filter unit, when there are multiple other color light filter units, the multiple other color light filter units can also adopt one, two or three of the above three settings. For example: assuming that three blue light filter units 112a are set on the filter film 100, the three blue light filter units 112a can all adopt the first setting method, or the first blue light filter unit 112a adopts the first setting method, the second blue light filter unit 112a adopts the second setting method, and the third blue light filter unit 112a adopts the third setting method.

[0077] The embodiments of the present application do not specifically limit the number and arrangement of the filter units for other color lights. It is only necessary to ensure that the corresponding areas of each filter unit on the infrared cut-off film 110 do not overlap. Those skilled in the art can make appropriate adjustments based on actual conditions.

[0078] Furthermore, depending on the actual situation, the filter units can be set in different areas of the infrared cut-off film 110, for example: all filter units (including the red light filter unit 111 and the filter units for other color lights) are set in the edge area of ​​the infrared cut-off film 110; or, some filter units are set in the edge area of ​​the infrared cut-off film 110, and another part of the filter units are set in the middle area of ​​the infrared cut-off film 110, etc. The embodiments of the present application also do not make specific limitations on this.

[0079] For example, the filter unit includes a red light filter unit 111 and other color light filter units, and the other color light filter units include a blue light filter unit 112a and a green light filter unit 112b. Fig. 9 , Fig. 9 A schematic diagram of an area where a filter unit is located on an infrared cut-off film provided in an embodiment of the present application.

[0080] like Fig. 9 As shown, all the filter units are arranged at the edge area of ​​the infrared cut-off film 110, and the edge area includes four sub-areas, and the four sub-areas are symmetrically adjacently arranged at four right angles of the infrared cut-off film 110. In each sub-area, the red light filter unit 111, the blue light filter unit 112a, and the green light filter unit 112b are alternately arranged on the infrared cut-off film 110.

[0081] Based on the filter film 100 in the above embodiment, the present application embodiment further provides a filter 200, please refer to Fig.10 , Fig.10 This is a schematic structural diagram of a filter provided in an embodiment of the present application. The filter 200 includes a filter film 100 and a substrate 210 as in the above embodiment, wherein the filter film 100 is disposed on the upper surface of the substrate 210 .

[0082] Specifically, the substrate 210 can be made of a variety of materials, such as glass, silicon wafer, sapphire, polyimide film, etc. The implementation of the filter film 100 in this embodiment is similar to the implementation of the filter film 100 in the above embodiment. The difference is that four configuration modes are provided for a filter unit for other color lights.

[0083] First, the filter unit 112 for other color lights is obtained by filling a filter material in a filling unit included in the infrared cutoff film 110 , and the filling unit includes a filling groove provided on the upper surface of the infrared cutoff film 110 .

[0084] Secondly, the filter unit 112 for other color lights is obtained by filling a filter material in a filling unit included in the infrared cutoff film 110 , and the filling unit includes a filling hole arranged on the lower surface of the infrared cutoff film 110 .

[0085] Thirdly, the filter unit 112 for other color lights is disposed on the outer surface of the infrared cut-off film 110 .

[0086] The first to third configurations are similar to the first to third configurations in the filter film 100 , and will not be described in detail herein.

[0087] For the fourth type, please refer to Fig.11 , Fig.11 The schematic diagram is a fourth arrangement of the filter units for other color lights in the filter provided in the embodiment of the present application. The filter units 112 for other color lights are arranged on a side of the substrate 210 away from the filter film 100 .

[0088] Based on the filter film 100 in the above embodiment, the present application embodiment also provides a fingerprint recognition module, please refer to Fig.12 , Fig.12 The structure diagram of a fingerprint recognition module provided in an embodiment of the present application is shown in FIG. 300. The fingerprint recognition module 300 may include: the filter film 100 in the above embodiment and a sensor 310. The sensor 310 includes a photosensitive pixel array, and the photosensitive pixel array includes a plurality of photosensitive units; the filter film 100 is disposed above the sensor 310, and the filter unit is disposed correspondingly to the photosensitive unit in the sensor 310.

[0089] Specifically, the optical signal used for fingerprint recognition passes through the filter unit on the filter film 100 and reaches the photosensitive unit corresponding to the filter unit in the sensor 310. The photosensitive unit recognizes the authenticity of the fingerprint based on the received optical signal. In other words, the filter film 100 can be set above the sensor 310. Since the thickness of the entire fingerprint recognition module is small, an ultra-thin fingerprint recognition device can be realized.

[0090] In some embodiments, the filter film 100 is disposed on the photosensitive surface of the sensor 310 .

[0091] Based on the fingerprint recognition module 300 in the above embodiment, the embodiment of the present application further provides an electronic device 400, which may include a display panel 410 and the fingerprint recognition module 300 in the above embodiment, wherein the fingerprint recognition module 300 is arranged below the display panel 410.

[0092] For further information, please refer to Fig.13 , Fig.13This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. The electronic device 400 also includes: a first light-transmitting layer 420, which is arranged on the infrared cut-off film 110; an adhesive light-transmitting layer 430, which is arranged on the first light-transmitting layer 420; and an optical signal guiding structure layer 440, which is arranged on the adhesive light-transmitting layer 430.

[0093] Among them, the optical signal guiding structure layer 440 includes: an aperture layer 441, which is arranged on the adhesive light-transmitting layer 430; the aperture layer 441 is provided with a plurality of aperture holes 442; a lens array layer 443, which is arranged on the aperture layer 441, and the lens array layer 443 is provided with a plurality of microlens structures 444, and the plurality of microlens structures 444 correspond one-to-one to the plurality of aperture holes 442.

[0094] The reflected light from the finger 450 touching the display panel 410 passes through the first light-transmitting layer 420 , the adhesive light-transmitting layer 430 and the infrared cut-off film 110 , and is absorbed by the sensor 310 , thereby performing anti-counterfeiting detection and fingerprint recognition.

[0095] Similarly, based on the filter 200 in the above embodiment, the present application embodiment also provides another fingerprint recognition module 500, please refer to Fig.14 , Fig.14 This is a schematic diagram of the structure of another fingerprint recognition module provided in an embodiment of the present application. The fingerprint recognition module 500 may include: the filter 200 in the above embodiment and the sensor 510. The sensor 510 includes a photosensitive pixel array, and the photosensitive pixel array includes a plurality of photosensitive units; the filter 200 is arranged above the sensor 510, and the filter unit is arranged corresponding to the photosensitive unit in the sensor 510.

[0096] Specifically, the optical signal used for fingerprint recognition passes through the filter unit on the filter 200 and reaches the photosensitive unit corresponding to the filter unit in the sensor 510, and the photosensitive unit identifies the authenticity of the fingerprint based on the received optical signal. In other words, the filter 200 can be set above the sensor 510, and the filter film 100 in the filter 200 can be set above the substrate 210, so that a lens-type fingerprint recognition device can be realized.

[0097] Based on the fingerprint recognition module 500 in the above embodiment, the embodiment of the present application also provides another electronic device 600, which may include a display panel and the fingerprint recognition module 500 in the above embodiment, wherein the fingerprint recognition module 500 is arranged below the display panel.

[0098] For further information, please refer to Fig.15 , Fig.15A schematic diagram of the structure of an electronic device provided in an embodiment of the present application, the electronic device 600 also includes: a lens 620; the lens 620 includes a lens barrel 621 and a lens 622, and the lens 622 is fixed in the lens barrel 621; the infrared cutoff film 110 is fixed in the lens barrel 621; the sensor 510 is arranged at the bottom of the lens barrel 621 and opposite to the lens 622.

[0099] In practical applications, the infrared cut-off film 110 can be integrated into the lens 620. During the manufacturing process of the lens 620, the infrared cut-off film 110 can be assembled in the lens barrel 621 of the lens 620 by a direct patch process, which simplifies the assembly process steps of the electronic device 600, reduces the assembly cost, improves the fitting accuracy of the infrared cut-off film 110, and improves the yield rate of the electronic device 600.

[0100] In some embodiments, the filter 200 is disposed on the photosensitive surface of the sensor 510 , for example, attached to the sensor 510 by optical adhesive.

[0101] Next, the present application also provides a method for preparing a filter film, which is used to prepare the filter film in the above embodiment. Fig.16 , Fig.16 A flowchart of a method for preparing a filter film provided in an embodiment of the present application, the method for preparing the filter film may include the following steps:

[0102] Step S1601: preparing an infrared cut-off film on the upper surface of the target substrate.

[0103] Step S1602: adjusting the thickness of the first target area in the infrared cut-off film to obtain a red light filter unit.

[0104] Specifically, an infrared cut-off film may be prepared on the upper surface of the target substrate, wherein the infrared cut-off film may be prepared by coating sub-film layers layer by layer (as described in the above embodiment). Then, a red light filter unit is obtained by adjusting the thickness of a portion of the infrared cut-off film, so that the red light filter unit can allow part or all of the red light signal to pass through.

[0105] For the above step S1601, as an implementation method, the target substrate may be a sensor, the sensor includes a photosensitive pixel array, the photosensitive pixel array includes a plurality of photosensitive units, and the first target area is an area corresponding to one or more photosensitive units. Figure 2 Therefore, an infrared cut-off film can be prepared on the upper surface of the sensor.

[0106] As another embodiment, the target substrate may be a substrate, which is disposed above the sensor, the sensor includes a photosensitive pixel array, the photosensitive pixel array includes a plurality of photosensitive units, and the first target area is an area corresponding to one or more photosensitive units. Fig.10 Therefore, the infrared cut-off film can be prepared on the upper surface of the substrate, and the substrate is located above the sensor, so a lens-type fingerprint recognition device can be realized based on the filter.

[0107] Regarding the above step S1602, as an implementation manner, the above step S1602 may specifically include the following steps:

[0108] The first target area in the infrared cut-off film is thinned to obtain a red light filter unit.

[0109] Taking the infrared cut-off film multilayer sub-film layer as an example, the preparation method of the filter film provided in the embodiment of the present application may include the following steps:

[0110] In the first step, a multilayer sub-film layer is prepared on the upper surface of the target substrate.

[0111] In the second step, redundant sub-film layers are removed in the first target area of ​​the multi-layer sub-film layers to obtain a red light filtering unit.

[0112] With the above Figure 3 Corresponding to the arrangement of the filter units of other color lights in the filter film shown, after the above step S1602, the method for preparing the filter film provided in the embodiment of the present application may further include the following steps:

[0113] In the first step, the thickness of the second target area in the infrared cut-off film is reduced to obtain a filled groove.

[0114] In the second step, filter materials are added into the filling grooves to obtain filter units for light of other colors except red light.

[0115] With the above Figure 4 Corresponding to the arrangement of the filter units of other color lights in the filter film shown, before the above step S1601, the preparation method of the filter film provided in the embodiment of the present application may further include the following steps:

[0116] Adding filter material to the upper surface of the sensor obtains filter units for light of other colors except red light.

[0117] With the above Figure 5 Corresponding to the arrangement of the filter units of other color lights in the filter film shown, after the above step S1602, the method for preparing the filter film provided in the embodiment of the present application may further include the following steps:

[0118] Adding filter material on the upper surface of the infrared cut-off film obtains filter units for light of other colors except red light.

[0119] With the above Fig.11 Corresponding to the arrangement of the filter units of other color lights in the filter shown, before the above step S1601, the method for preparing the filter film provided in the embodiment of the present application may further include the following steps:

[0120] Adding filter material on the upper surface of the substrate obtains filter units for light of other colors except red light.

[0121] Therefore, filter units corresponding to other color lights may be provided in the filter film to further improve the anti-counterfeiting performance of the fingerprint recognition device against real and fake fingerprints.

[0122] Furthermore, in the above embodiment, the step of adding the filter material may specifically include the following steps:

[0123] The filter material is coated by material addition, wherein the material addition method includes spraying or spot coating.

[0124] Therefore, by adopting a low-precision material addition method to coat the filter material, the difficulty of the process is reduced and consumables are reduced.

[0125] Finally, the present application also provides a fingerprint anti-counterfeiting identification method, which is used to realize fingerprint anti-counterfeiting identification by using the filter film or filter in the above embodiment. Fig.17 , Fig.17 A flowchart of a fingerprint anti-counterfeiting identification method provided in an embodiment of the present application, the fingerprint anti-counterfeiting identification method may include the following steps:

[0126] Step S1701: Acquire a light signal received by a photosensitive unit, wherein the light signal passes through a filter film or a filter unit in a filter plate and is then received by the photosensitive unit.

[0127] Step S1702: Authenticity identification of fingerprints based on the optical signal.

[0128] Therefore, when using the filter film or filter provided in the embodiment of the present application, on the basis of using the infrared cutoff film to achieve sunlight protection, the passing red light signal can be used to distinguish between true and false fingerprints, thereby improving the anti-counterfeiting performance of the fingerprint recognition device with sunlight protection effect for true and false fingerprints.

[0129] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0130] In addition, the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0131] Furthermore, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0132] It should be noted that if the function is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM) random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0133] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0134] The above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A filter film, characterized in that: include: An infrared cut-off film, wherein a red light filter unit is provided in the infrared cut-off film, and the red light filter unit is used to pass part or all of the red light signal; Among them, the red light filtering unit is obtained by adjusting the thickness of the infrared cut-off film, the thickness of the red light filtering unit is not 0, and the red light filtering unit is a groove distributed in the infrared cut-off film, wherein the groove allows part or all of the red light signal to pass through.

2. The filter film according to claim 1, characterized in that: The infrared cut-off film includes multiple sub-film layers, wherein the film layer of the red light filtering unit is a partial sub-film layer in the multiple sub-film layers, and the partial sub-film layer allows part or all of the red light signal to pass through.

3. The filter film according to claim 2, characterized in that: The red light filtering unit is obtained by removing redundant sub-film layers in the multi-layer sub-film layers, wherein the redundant sub-film layers are sub-film layers in the multi-layer sub-film layers except for the partial sub-film layers.

4. The filter film according to any one of claims 1 to 3, characterized in that: The red light filter unit is further used to pass other light signals adjacent to the wavelength band of the red light signal.

5. The filter film according to any one of claims 1 to 3, characterized in that: The filter film is also provided with filter units for light of other colors except the red light, for passing light signals of other colors.

6. The filter film according to claim 5, characterized in that: The filter unit for other color lights is obtained by filling a filter material in a filling unit included in the infrared cut-off film; Alternatively, the filter unit for light of other colors is arranged on the outer surface of the infrared cut-off film.

7. The filter film according to claim 6, characterized in that: The filling unit includes a filling groove provided on the upper surface of the infrared cut-off film; and / or, The filling unit includes a filling hole provided on a lower surface of the infrared cut-off film.

8. The filter film according to any one of claims 1 to 3, characterized in that: Part or all of the filter units are arranged at the edge area of ​​the infrared cut-off film.

9. The filter film according to claim 8, characterized in that: The edge region includes four sub-regions; The four sub-regions are symmetrically and adjacently arranged at four right angles of the infrared cut-off film.

10. A filter, characterized in that: include: The filter film according to any one of claims 1 to 9; The substrate is provided with the filter film on the upper surface of the substrate.

11. A fingerprint recognition module, characterized in that: include: The filter film according to any one of claims 1 to 9; A sensor, comprising a photosensitive pixel array, wherein the photosensitive pixel array comprises a plurality of photosensitive units; Wherein, the filter film is arranged above the sensor, and the filter unit is arranged corresponding to the photosensitive unit in the sensor.

12. The fingerprint recognition module according to claim 11, characterized in that: The filter film is arranged on the photosensitive surface of the sensor.

13. A fingerprint recognition module, characterized in that: include: The optical filter according to claim 10; A sensor, comprising a photosensitive pixel array, wherein the photosensitive pixel array comprises a plurality of photosensitive units; Wherein, the filter is arranged above the sensor, and the filter unit is arranged corresponding to the photosensitive unit in the sensor.

14. A method for preparing a filter film, characterized in that: include: preparing an infrared cut-off film on an upper surface of a target substrate; Adjusting the thickness of the first target area in the infrared cut-off film to obtain a red light filtering unit; The red light filtering unit allows part or all of the red light signal to pass through, the thickness of the red light filtering unit is not 0, and the red light filtering unit is a groove distributed in the infrared cut-off film, wherein the groove allows part or all of the red light signal to pass through.

15. The method for preparing the filter film according to claim 14, characterized in that: The filter unit for adjusting the thickness of the first target area in the infrared cut-off film to obtain red light comprises: The first target area in the infrared cut-off film is thinned to obtain the red light filtering unit.

16. The method for preparing the filter film according to claim 15, characterized in that: The method of preparing an infrared cut-off film on the upper surface of a target substrate comprises: preparing a multi-layer sub-film layer on the upper surface of the target substrate; The method of performing a thinning process on the first target area in the infrared cut-off film to obtain the red light filtering unit comprises: In the first target area of ​​the multi-layer sub-film layer, redundant sub-film layers are removed to obtain the red light filtering unit.

17. The method for preparing a filter film according to any one of claims 14 to 16, characterized in that: The target substrate is a sensor, the sensor includes a photosensitive pixel array, and the photosensitive pixel array includes a plurality of photosensitive units; The first target area is an area corresponding to one or more photosensitive units.

18. The method for preparing a filter film according to any one of claims 14 to 16, characterized in that: The target substrate is a substrate, the substrate is arranged above the sensor, the sensor includes a photosensitive pixel array, and the photosensitive pixel array includes a plurality of photosensitive units; The first target area is an area corresponding to one or more photosensitive units.

19. The method for preparing the filter film according to claim 18, characterized in that: Before preparing the infrared cut-off film on the upper surface of the target substrate, the method further comprises: Adding filter material on the upper surface of the substrate obtains filter units for light of other colors except red light.

20. The method for preparing a filter film according to claim 18, characterized in that: Before preparing the infrared cut-off film on the upper surface of the target substrate, the method further comprises: Adding filter material on the upper surface of the sensor obtains filter units for light of other colors except red light.

21. The method for preparing a filter film according to claim 18, characterized in that: After adjusting the thickness of the first target area in the infrared cut-off film to obtain a red light filter unit, the method further includes: Reducing the thickness of a second target area in the infrared cut-off film to obtain a filled groove; wherein the second target area is an area corresponding to one or more photosensitive units; Adding filter material into the filling groove obtains filter units for light of other colors except red light.

22. The method for preparing a filter film according to any one of claims 14 to 16, characterized in that: After adjusting the thickness of the first target area in the infrared cut-off film to obtain a red light filter unit, the method further includes: A filter material is added to the upper surface of the infrared cut-off film to obtain a filter unit for light of other colors except red light.

23. The method for preparing a filter film according to claim 19, characterized in that: The added filter material comprises: The filter material is coated by material addition, wherein the material addition method includes spraying or spot coating.

24. A fingerprint anti-counterfeiting identification method, characterized in that: include: Acquiring an optical signal received by a photosensitive unit, wherein the optical signal is received by the photosensitive unit after passing through the optical filter unit in the optical filter film according to any one of claims 1 to 9 or the optical filter unit in the optical filter sheet according to claim 10; The authenticity of the fingerprint is identified based on the optical signal.

25. An electronic device, characterized in that: The electronic device comprises a display panel and the fingerprint recognition module according to claim 11 or the fingerprint recognition module according to claim 12 or 13; The fingerprint recognition module is arranged below the display panel.

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