CN113552663A

CN113552663A - Filter film and preparation method thereof, optical filter, fingerprint identification module and identification method

Info

Publication number: CN113552663A
Application number: CN202110743376.1A
Authority: CN
Inventors: 孙建成
Original assignee: Beijing Jihao Technology Co Ltd
Current assignee: Beijing Jihao Technology Co Ltd
Priority date: 2021-07-01
Filing date: 2021-07-01
Publication date: 2021-10-26

Abstract

The application provides a filter coating and preparation method, light filter, fingerprint identification module and identification method, is applied to the fingerprint identification field, and wherein, the filter coating includes: the infrared cut-off film is internally provided with a red light filtering unit, and the red light filtering unit is used for passing part or all of red light signals; wherein, the red light filtering unit is obtained by adjusting the thickness of the infrared cut-off film. In the above scheme, the thickness of the infrared cut film is adjusted so that the red light signal can pass through the region corresponding to the red light filtering unit on the infrared cut film. Therefore, when the filter coating provided by the embodiment of the application is adopted, on the basis that the infrared cut-off film is adopted to realize sunlight prevention, the passing red light signal can be utilized to realize the distinguishing of true and false fingerprints, so that the anti-counterfeiting performance of the fingerprint identification device with the sunlight prevention effect on the true and false fingerprints is improved.

Description

Filter film and preparation method thereof, optical filter, fingerprint identification module and identification method

Technical Field

The application relates to the field of fingerprint identification, in particular to a light filtering film, a preparation method of the light filtering film, a light filter, a fingerprint identification module and an identification method.

Background

With the rapid development of the electronic 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 applied to electronic devices in recent years. Specifically, a fingerprint identification device on an electronic device usually collects an optical signal carrying fingerprint information, so as to implement a fingerprint unlocking function.

In practical applications, an infrared Cut film (IR-Cut) is usually disposed on the fingerprint recognition device, and since the Cut-off wavelength of the IR-Cut film is generally less than 605 nanometers (nm), the purpose of sunlight protection can be achieved. The fingerprint identification device with the sunlight prevention effect in the prior art has poor anti-counterfeiting performance for true and false fingerprints.

Disclosure of Invention

An object of the embodiments of the present application is to provide a filter film and a preparation method thereof, an optical filter, a fingerprint identification module and an identification method thereof, so as to solve the technical problem that the fingerprint identification device with a sunlight prevention effect has a poor anti-counterfeit performance for real and false fingerprints.

In a first aspect, an embodiment of the present application provides a film filter, including: the infrared cut-off film is internally provided with a red light filtering unit, and the red light filtering unit is used for passing part or all of red light signals; wherein the red light filtering unit is obtained by adjusting the thickness of the infrared cut-off film. In the above scheme, the thickness of the infrared cut film is adjusted so that the red light signal can pass through the region corresponding to the red light filtering unit on the infrared cut film. Therefore, when the filter coating provided by the embodiment of the application is adopted, on the basis that the infrared cut-off film is adopted to realize sunlight prevention, the passing red light signal can be utilized to realize the distinguishing of true and false fingerprints, so that the anti-counterfeiting performance of the fingerprint identification device with the sunlight prevention effect on the true and false fingerprints is improved.

In an alternative embodiment, the infrared cut film includes a plurality of sub-film layers, wherein the film layer of the red light filtering unit is a partial sub-film layer of the plurality of sub-film layers, and the partial sub-film layer allows a part or all of a red light signal to pass through. In the above scheme, can realize the anti-fake effect of infrared cut-off membrane through setting up multilayer sub-film layer, on this basis, the rete of ruddiness light filtering unit is part sub-film layer wherein, because the number of piles of ruddiness light filtering unit is less than the number of piles of infrared cut-off membrane, consequently can see through more red light signal to can utilize the red light signal who passes through to realize the differentiation of true and false fingerprint, thereby improve the fingerprint identification device who possesses the anti-fake performance to true and false fingerprint.

In an alternative embodiment, the red light filtering unit is obtained by removing an excess sub-film layer in the multi-layer sub-film layer, wherein the excess sub-film layer is the sub-film layer except for the partial sub-film layer in the multi-layer sub-film layer. In the above scheme, after the infrared cut film is implemented by disposing the plurality of sub-film layers, a part of the redundant sub-film layers in the plurality of sub-film layers may be removed, and the remaining part of the sub-film layers may transmit more red light signals. Therefore, as only a part of the plurality of sub-film layers needs to be removed, the process is simpler and the material consumption is less compared with the prior art scheme of adding the red light filter material.

In an alternative embodiment, the red light filter element 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.

In an alternative embodiment, the red light filter unit is further configured 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 red light filtering units, the red light filtering units can also pass through other light signals adjacent to the red light signal wave band, 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.

In an alternative embodiment, a filter unit for light of another color than the red light is further disposed in the filter film, and is configured to pass light signals of another color. In the above scheme, the filter film can also be provided with filter units corresponding to other color lights, so that the anti-counterfeiting performance of the fingerprint identification device for true and false fingerprints is further improved.

In an alternative embodiment, the filter unit for the other color light is obtained by filling a filter material in a filling unit included in the infrared cut film; alternatively, the filter unit of the other color light is disposed on an outer surface of the infrared cut film.

In an alternative embodiment, the filling unit includes a filling groove provided on an upper surface of the infrared cut film; and/or the filling unit comprises a filling hole arranged on the lower surface of the infrared cut-off film.

In an alternative embodiment, part or all of the filter unit is disposed at an edge region of the infrared cut film.

In an alternative embodiment, the edge region comprises four sub-regions; the four sub-regions are symmetrically and adjacently arranged at four right angles of the infrared cut-off film.

In a second aspect, an embodiment of the present application provides an optical filter, including: a filter as described in any one of the previous embodiments; the filter film is arranged on the upper surface of the substrate.

In an optional embodiment, the optical filter further includes a filter unit for light of another color than the red light, and the filter unit is disposed on a side of the substrate away from the filter film.

In a third aspect, an embodiment of the present application provides a fingerprint identification module, including: a filter as described in any one of the previous embodiments; a sensor comprising a photosensitive pixel array comprising a plurality of photosensitive cells; the filter film is arranged above the sensor, and the filter unit is arranged corresponding to the photosensitive unit in the sensor. In above-mentioned scheme, the filter coating can set up the top at the sensor, because the thickness of whole fingerprint identification module is less, consequently can realize the fingerprint identification device of ultra-thin formula.

In a fourth aspect, an embodiment of the present application provides a fingerprint identification module, including: the optical filter according to the foregoing embodiment; a sensor comprising a photosensitive pixel array comprising a plurality of photosensitive cells; the optical filter is arranged above the sensor, and the optical filtering unit and the photosensitive unit in the sensor are correspondingly arranged. In the above scheme, the optical filter can be arranged above the sensor, and the filter film in the optical filter can be arranged above the substrate, so that the lens-type fingerprint identification device can be realized.

In a fifth aspect, an embodiment of the present application provides a method for preparing a filter film, including: preparing an infrared cut-off film on the upper surface of a target substrate; the thickness of a first target area in the infrared cut-off film is adjusted to obtain a red light filtering unit; wherein, the red light filter unit makes part or all of the red light signal pass through. In the above scheme, after the infrared cut film is prepared on the target substrate, the red light filtering unit may be obtained by adjusting the thickness of a partial region in the infrared cut film. Therefore, when the filter coating provided by the embodiment of the application is adopted, on the basis that the infrared cut-off film is adopted to realize sunlight prevention, the passing red light signal can be utilized to realize the distinguishing of true and false fingerprints, so that the anti-counterfeiting performance of the fingerprint identification device with the sunlight prevention effect on the true and false fingerprints is improved. In addition, as only the thickness of the infrared cut-off film needs to be adjusted, compared with the scheme of adding the red light filter material in the prior art, the process is simpler and the material consumption is less.

In an alternative embodiment, the filter unit for adjusting the thickness of the first target region in the infrared cut film to obtain red light includes: and thinning the first target area in the infrared cut-off film to obtain the red light filtering unit.

In an alternative embodiment, the preparing an infrared cut film on the upper surface of the target substrate includes: preparing a multilayer sub-film layer on the upper surface of the target substrate; the light filtering unit for obtaining the red light by thinning the first target area in the infrared cut-off film comprises: and removing redundant sub-film layers in the first target area in the multilayer sub-film layers to obtain the red light filtering unit.

In an alternative embodiment, the target substrate is a sensor comprising a photosensitive pixel array comprising a plurality of photosensitive cells; the first target region is a region corresponding to one or more photosensitive cells. In the scheme, the infrared cut-off film can be prepared on the upper surface of the sensor, and the prepared filter film is small in thickness, so that the ultrathin fingerprint identification device can be realized based on the filter film.

In an alternative embodiment, the target substrate is a substrate, the substrate is disposed above a sensor, the sensor includes a photosensitive pixel array, and the photosensitive pixel array includes a plurality of photosensitive cells; the first target region is a region corresponding to one or more photosensitive cells. In the above scheme, the infrared cut-off film can be prepared on the upper surface of the substrate, and the substrate is positioned above the sensor, so that the lens-type fingerprint identification device can be realized based on the optical filter.

In an alternative embodiment, before the preparing the infrared cut film on the upper surface of the target substrate, the method further comprises: and the light filtering unit is used for adding a light filtering material on the upper surface of the substrate to obtain light with other colors except the red light. In the above scheme, the filter film can also be provided with filter units corresponding to other color lights, so that the anti-counterfeiting performance of the fingerprint identification device for true and false fingerprints is further improved.

In an alternative embodiment, before the preparing the infrared cut film on the upper surface of the target substrate, the method further comprises: and the filter unit is used for adding filter materials on the upper surface of the sensor to obtain light of other colors except the red light. In the above scheme, the filter film can also be provided with filter units corresponding to other color lights, so that the anti-counterfeiting performance of the fingerprint identification device for true and false fingerprints is further improved.

In an alternative embodiment, after the adjusting the thickness of the first target region in the infrared cut film to obtain the filter unit of the red light, the method further includes: reducing the thickness of a second target area in the infrared cut-off film to obtain a filling groove; wherein the second target region is a region corresponding to one or more photosensitive cells; and a filter unit for adding filter material into the filling groove to obtain light of other colors except red light. In the above scheme, the filter film can also be provided with filter units corresponding to other color lights, so that the anti-counterfeiting performance of the fingerprint identification device for true and false fingerprints is further improved.

In an alternative embodiment, after the adjusting the thickness of the first target region in the infrared cut film to obtain the filter unit of the red light, the method further includes: and the filtering unit is used for adding a filtering material on the upper surface of the infrared cut-off film to obtain light with other colors except the red light. In the above scheme, the filter film can also be provided with filter units corresponding to other color lights, so that the anti-counterfeiting performance of the fingerprint identification device for true and false fingerprints is further improved.

In an alternative embodiment, the additive optical filter material includes: and coating the filter material by adopting a material adding method, wherein the material adding method comprises a spraying or point coating method. In the scheme, the coating of the filtering material is carried out in a low-precision material addition mode, so that the difficulty of the process is reduced, and the consumable material is reduced.

In a sixth aspect, an embodiment of the present application provides a fingerprint anti-counterfeit identification method, including: acquiring a light signal received by a photosensitive unit, wherein the light signal is received by the photosensitive unit after passing through a filtering unit in a filter film according to any one of the foregoing embodiments or a filtering unit in a filter according to the foregoing embodiments; and identifying the authenticity of the fingerprint according to the optical signal. In the above-mentioned scheme, when adopting the filter coating or the light filter that this application embodiment provided, on the basis that adopts infrared cut-off membrane to realize anti-sunlight, can utilize the red light signal who passes through to realize distinguishing of true and false fingerprint to improve the fingerprint identification device that possesses the anti-sunlight effect and to true and false fingerprint's anti-fake performance.

In a seventh aspect, an embodiment of the present application provides an electronic device, where the electronic device includes a display panel and the fingerprint identification module according to the foregoing embodiment; the fingerprint identification module set up in display panel's below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a filter film according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram illustrating an internal structure of a filter according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram illustrating an arrangement of a first filtering unit for other color light in a filter film according to an embodiment of the present disclosure;

FIG. 4 is a schematic diagram illustrating an arrangement of a second filtering unit for other color light in a filter film according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of an internal structure of a second other color filter unit in the filter film according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram illustrating an arrangement of a filter unit for a third other color light in a filter film according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram illustrating an arrangement of a plurality of filtering units for other colors of light in a filter film according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram illustrating an arrangement of a plurality of filtering units for other colors of light in a filter film according to an embodiment of the present disclosure;

fig. 9 is a schematic diagram of an area of a filter unit on an infrared cut film according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of an optical filter according to an embodiment of the present disclosure;

fig. 11 is a schematic diagram illustrating an arrangement manner of a filter unit of a fourth other color light in the filter according to the embodiment of the present application;

fig. 12 is a schematic structural diagram of a fingerprint identification module according to an embodiment of the present disclosure;

fig. 13 is a schematic structural diagram of an electronic device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of another fingerprint identification module according to an embodiment of the present disclosure;

fig. 15 is a schematic structural diagram of another electronic device provided in an embodiment of the present application;

FIG. 16 is a flowchart illustrating a method for fabricating a filter according to an embodiment of the present disclosure;

fig. 17 is a flowchart of a fingerprint anti-counterfeit identification method according to an embodiment of the present application.

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

Detailed Description

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application.

Referring to fig. 1, fig. 1 is a schematic structural view of a filter according to an embodiment of the present disclosure, where the filter 100 may include: an infrared cut film 110. The infrared cut film 110 is provided therein with a red light filter unit 111 for passing a part or all of a red light signal, and the red light filter unit 111 is obtained by adjusting the thickness of the infrared cut film 110.

Specifically, the infrared cut film 110 is an optical thin film for blocking the transmission of an optical signal in the infrared band. Among them, the cut-off wavelength of the infrared cut-off film 110 is generally 605nm, the wavelength of an optical signal of an infrared band is generally between 760nm and 1mm, the wavelength of sunlight is generally between 400nm and 760nm, and the wavelength of red light is generally between 620nm and 760 nm. Therefore, a red light signal and an infrared light signal having a wavelength of more than 606nm are hardly transmitted through the infrared cut film, and the best signals for distinguishing a true or false fingerprint are the red light signal and the infrared light signal. That is, although the infrared cut-off film 110 can prevent sunlight, i.e., prevent the interference of infrared rays to fingerprint identification, the anti-counterfeit performance for genuine and counterfeit fingerprints is poor.

Based on this, in the embodiment of the present application, the thickness of some regions of the infrared cut-off film 110 is adjusted to obtain the red light filtering unit 111, so that part or all of the red light signal can pass through the red light filtering unit 111, so as to identify the true and false fingerprint according to the passed part or all of the red light signal. Therefore, when the light filter film 100 provided by the embodiment of the application is used, on the basis of realizing sunlight prevention by using the infrared cut-off film 110, the passing red light signal can be used for distinguishing true and false fingerprints, so that the anti-counterfeiting performance of the fingerprint identification device with the sunlight prevention effect on the true and false fingerprints is improved.

It is understood that a part or all of the red light signal refers to a part of the red light signal or a whole red light signal in the red light signal, for example: passing a red light signal having a wavelength in a range of 620nm to 700 nm; alternatively, a red light signal in the wavelength range between 620nm-760nm is passed.

As an implementation manner, referring to fig. 2, fig. 2 is a schematic diagram of an internal structure of a filter film provided in an embodiment of the present disclosure, and it can be seen that the infrared cut-off film 110 may include a plurality of sub-film layers, where a film layer of the red light filtering unit 111 is a partial sub-film layer of the plurality of sub-film layers, and the partial sub-film layer allows a part or all of a red light signal to pass through.

The number of layers of the multilayer sub-film layer and the number of layers of a part of the sub-film layer may be determined in advance by a manufacturer, and the multilayer sub-film layer may be sequentially plated according to the determined number of layers in the process of preparing the filter film 100 provided in the embodiment of the present application. Then, the excess sub-film layers (i.e., the sub-film layers except for a part of the sub-film layers) in some regions of the multi-layer sub-film layers can be removed, so as to obtain the red light filtering unit 111. That is to say, the filter unit 111 for red light can be obtained by removing the redundant sub-film layers in the multi-layer sub-film layers, and therefore, since only a part of the sub-film layers in the multi-layer sub-film layers need to be removed, compared with the scheme of adding the red light filter material in the prior art, the process of the filter film 100 provided by the embodiment of the present application is simpler and consumes less materials.

It is understood that the number of layers of the multi-layer sub-film layer and the number of layers of the partial sub-film layer shown in fig. 2 are examples, and those skilled in the art should adjust the number of layers of the multi-layer sub-film layer and the number of layers of the partial sub-film layer according to actual situations. In addition, the specific film layer composition of the infrared cut film 110 is not specifically limited in the embodiments of the present application, and those skilled in the art can also appropriately adjust the composition according to the actual situation.

For example, the infrared cut film 110 may include silicon oxide and titanium oxide, and the silicon oxide and the titanium oxide are disposed at intervals, i.e., a layer of silicon oxide, a layer of titanium oxide, and so on. The number of layers of the infrared cut film 110 may be 70, and the number of layers of the filter unit 111 for red light may be 45. Therefore, 70 sub-film layers can be plated in the order of a silicon oxide layer and a titanium oxide layer to obtain the infrared cut-off film 110; then, 25 redundant sub-film layers in some areas of the 70 sub-film layers are removed, and the obtained 45-layer sub-film layer is the red light filtering unit 111.

In the embodiment of the present application, the removing of the excess sub-film layer may be performed by thinning.

After removing the excessive sub-film layer on the infrared cut film 110, as shown in fig. 2, it can be seen that the filter unit 111 for red light is a groove distributed in the infrared cut film 110, wherein the groove allows a part or all of the red light signal to pass through.

It is understood that, since the number of the sub-film layers corresponding to the red light filter unit 111 is related to the wavelength band of the transmitted light signal, the number of the sub-film layers corresponding to the red light filter unit may be less than or greater than the number of the sub-film layers that can just pass the wavelength band of the red light signal in the case where the precision of the instrument for removing the excess sub-film layers is low or the precision of the preparation personnel in determining the number of the excess sub-film layers is low.

In this case, the filter unit 111 for red light 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 filtering unit 111, other light signals adjacent to the red light signal band can be passed through, 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.

In the above scheme, can realize the anti-fake effect of infrared cut-off film 110 through setting up multilayer sub-film layer, on this basis, the rete of ruddiness filter unit 111 is wherein partial sub-film layer, because the number of piles of ruddiness filter unit 111 is less than the number of piles of infrared cut-off film 110, consequently can see through more red light signal, thereby can utilize the red light signal who passes through to realize the differentiation of true and false fingerprint, thereby improve the fingerprint identification device that possesses the anti-fake effect to true and false fingerprint's antifalsification ability.

Further, the filter film 100 provided in the embodiment of the present application may further include a filter unit 112 for light of another color than red light.

Specifically, in order to further improve the anti-counterfeit performance of the fingerprint identification device against the genuine and fake fingerprints, a filter unit of other color lights may be further disposed in the filter film 100, for example: a filter unit 112a for blue light, a filter unit 112b for green light, a filter unit for yellow light, etc. Wherein, the filter unit of each other color light is used for passing the corresponding color light, for example: the blue light filtering unit 112a is used to filter the blue light signal.

In the embodiment of the present application, three setting manners are provided for the filter unit of one other color light, and the following sequentially describes the three setting manners of the filter units of the other color light.

First, please refer to fig. 3, fig. 3 is a schematic diagram illustrating a setting manner of a first other color light filtering unit in a filter film according to an embodiment of the present disclosure. The filter unit 112 for the other color light is obtained by filling a filter material in a filling unit included in the infrared cut film 110, the filling unit including a filling groove provided on the upper surface of the infrared cut film 110.

As shown in fig. 3, similar to the red light filter unit 111, a filling groove may be formed on the infrared cut film 110 by adjusting the thickness of some regions of the infrared cut film 110, and the filling groove may be filled with a filter material, so as to obtain a filter unit for light of other colors.

It is understood that the height of the upper surface of the filtering unit for the light of other colors may be higher than the height of the upper surface of the infrared cut film 110 (see fig. 3); the height of the upper surface of the filter unit for the other color light may be lower than the height of the upper surface of the infrared cut film 110.

Second, please refer to fig. 4, fig. 4 is a schematic diagram illustrating a setting manner of a second other color light filtering unit in a filter film according to an embodiment of the present disclosure. The filter unit 112 for the other color light is obtained by filling a filter material in a filling unit included in the infrared cut film 110, the filling unit including a filling hole provided on the lower surface of the infrared cut film 110.

As shown in fig. 4, a filling hole may be formed on the lower surface of the infrared cut film 110, and a filter unit for light of another color may be obtained by filling a filter material in the filling hole.

It should be noted that the filling holes in fig. 4 are not formed by adjusting the thickness of the ir-cut film 110, and since the lower surface of the ir-cut film 110 is usually in contact with other objects (e.g., a sensor, a substrate 210, etc.), when preparing the filter film 100, a filter material may be added to some areas of the upper surface of the other objects to form a filter unit for light of other colors; then, the infrared cut-off film 110 is coated on the other areas of the upper surface of the object and the filtering units of other colors of light layer by layer.

Since some regions of the lower surface of the infrared cut film 110 are provided with the filter units of the other color lights, the height of the corresponding region of the upper surface of the infrared cut film 110 may be higher than the height of the other regions, as shown in fig. 5.

Third, referring to fig. 6, fig. 6 is a schematic view illustrating an arrangement manner of a filtering unit for a third other color light in a filtering film according to an embodiment of the present disclosure. The filter unit 112 for the other color light is disposed on the outer surface of the infrared cut film 110.

Fig. 3 to 6 each show only a filter unit for providing light of one color on the filter film 100, and it is understood that when a plurality of filter units for light of other colors are provided on the filter film 100, one, two or three of the three arrangements may be adopted. For example: assuming that the filter film 100 is provided with the blue light filter unit 112a and the green light filter unit 112b, the blue light filter unit 112a and the green light filter unit 112b may both adopt the third arrangement (as shown in fig. 7), or the blue light filter unit 112a adopts the second arrangement and the green light filter unit 112b adopts the third arrangement (as shown in fig. 8).

Of course, when there are a plurality of filtering units for the same other color light, one, two or three of the three setting modes may be adopted for the filtering units for the plurality of other color light. For example: assuming that three blue light filtering units 112a are disposed on the filter film 100, the three blue light filtering units 112a may all adopt a first arrangement manner, or a first blue light filtering unit 112a adopts a first arrangement manner, a second blue light filtering unit 112a adopts a second arrangement manner, and a third blue light filtering unit 112a adopts a third arrangement manner.

The number and the arrangement mode of the light filtering units of other colors of light are not specifically limited, and only by ensuring that the corresponding areas of each light filtering unit on the infrared cut-off film 110 are not overlapped, the skilled person can make appropriate adjustments according to actual conditions.

Further, the filter units may be disposed in different regions of the infrared cut film 110 according to actual situations, for example: all the filter units (including the filter unit 111 for red light and the filter units for other colors of light) are disposed in the edge area of the infrared cut film 110; or, a part of the filter units is disposed in an edge region of the infrared cut film 110, another part of the filter units is disposed in a middle region of the infrared cut film 110, and the like, which is not specifically limited in this embodiment of the application.

Taking the filter unit including the filter unit 111 for red light and the filter units for other colors of light, and the filter units for other colors of light including the filter unit 112a for blue light and the filter unit 112b for green light as an example, please refer to fig. 9, and fig. 9 is a schematic diagram of an area where the filter unit is located on the infrared cut-off film according to an embodiment of the present disclosure.

As shown in fig. 9, all the filter units are disposed at the edge region of the infrared cut-off film 110, and the edge region includes four sub-regions symmetrically disposed adjacent to four corners of the infrared cut-off film 110. In each sub-region, a filter unit 111 for red light, a filter unit 112a for blue light, and a filter unit 112b for green light are alternately disposed on the infrared cut film 110.

Referring to fig. 10, fig. 10 is a schematic structural diagram of a filter 200 according to an embodiment of the present disclosure, where the filter 200 includes the filter 100 according to the embodiment and a substrate 210, and the filter 100 is disposed on an upper surface of the substrate 210.

Specifically, the substrate 210 may be made of various materials, such as: glass, silicon wafer, sapphire, polyimide film, etc., and the implementation of the filter 100 in this embodiment is similar to the implementation of the filter 100 in the above-described embodiment. The difference is that four arrangements are provided for the filter unit for one other color of light.

First, the filter unit 112 for the other color light is obtained by filling a filter material in a filling unit included in the infrared cut film 110, the filling unit including a filling groove provided on the upper surface of the infrared cut film 110.

Second, the filter unit 112 for the other color light is obtained by filling a filter material in a filling unit included in the infrared cut film 110, the filling unit including a filling hole provided on the lower surface of the infrared cut film 110.

Third, the filter unit 112 of the other color light is disposed on the outer surface of the infrared cut film 110.

The first to third disposing manners are similar to the first to third disposing manners of the filter film 100, and are not described herein again.

Fourth, referring to fig. 11, fig. 11 is a schematic view illustrating an arrangement manner of a filter unit of fourth other color light in the filter according to the embodiment of the present application. The filter units 112 for the other colors of light are disposed on the side of the substrate 210 away from the filter 100.

Based on the filter film 100 in the above embodiment, an embodiment of the present application further provides a fingerprint identification module, please refer to fig. 12, where fig. 12 is a schematic structural diagram of the fingerprint identification module provided in the embodiment of the present application, and the fingerprint identification module 300 may include: the filter 100 and the sensor 310 in the above embodiments. The sensor 310 includes a photosensitive pixel array including a plurality of photosensitive cells; the filter film 100 is disposed above the sensor 310, and the filter unit is disposed corresponding to the photosensitive unit in the sensor 310.

Specifically, the light signal for fingerprint identification passes through the filtering unit on the filter film 100 and reaches the photosensitive unit corresponding to the filtering unit in the sensor 310, and the photosensitive unit identifies the authenticity of the fingerprint based on the received light signal. That is, the filter film 100 can be disposed above the sensor 310, and since the thickness of the entire fingerprint identification module is small, the ultra-thin fingerprint identification device can be realized.

In some embodiments, the filter film 100 is disposed on the light-sensitive surface of the sensor 310.

Based on the fingerprint identification module 300 in the above embodiment, the embodiment of the present application further provides an electronic device 400, where the electronic device 400 may include the display panel 410 and the fingerprint identification module 300 in the above embodiment, and the fingerprint identification module 300 is disposed below the display panel 410.

Further, referring to fig. 13, fig. 13 is a schematic structural diagram of an electronic device according to an embodiment of the present application, where the electronic device 400 further includes: a first light-transmitting layer 420 provided on the infrared cut film 110; an adhesive transparent layer 430 disposed on the first transparent layer 420; the optical signal guiding structure layer 440 is disposed on the adhesive transparent layer 430.

Wherein the optical signal guiding structure layer 440 includes: a diaphragm layer 441 disposed on the adhesive transparent layer 430; the diaphragm layer 441 is provided with a plurality of diaphragm holes 442; the lens array layer 443 is disposed on the stop layer 441, wherein the lens array layer 443 has a plurality of microlens structures 444, and the plurality of microlens structures 444 correspond to the plurality of stop holes 442 one by one.

The reflected light of the finger 450 touching the display panel 410 passes through the first transparent layer 420, the adhesive transparent layer 430 and the infrared cut-off film 110, and is absorbed by the sensor 310 for anti-counterfeit detection and fingerprint identification.

Similarly, based on the filter 200 in the above embodiment, another fingerprint identification module 500 is further provided in the embodiment of the present application, please refer to fig. 14, where fig. 14 is a schematic structural diagram of another fingerprint identification module provided in the embodiment of the present application, and the fingerprint identification module 500 may include: the filter 200 and the sensor 510 in the above embodiments. Wherein sensor 510 comprises a photosensitive pixel array comprising a plurality of photosensitive cells; the filter 200 is disposed above the sensor 510, and the filter unit is disposed corresponding to the photosensitive unit in the sensor 510.

Specifically, the optical signal for fingerprint identification passes through the filtering unit on the optical filter 200 and reaches the photosensitive unit corresponding to the filtering unit in the sensor 510, and the photosensitive unit identifies the authenticity of the fingerprint based on the received optical signal. That is, the filter 200 may be disposed above the sensor 510, and the filter film 100 in the filter 200 may be disposed above the substrate 210, so that a lens-type fingerprint recognition device may be implemented.

Based on the fingerprint identification module 500 in the above embodiment, the embodiment of the present application further provides another electronic device 600, and the electronic device 600 may include the display panel and the fingerprint identification module 500 in the above embodiment, wherein the fingerprint identification module 500 is disposed below the display panel.

Further, referring to fig. 15, fig. 15 is a schematic structural diagram of an electronic device according to an embodiment of the present application, where the electronic device 600 further 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 cut-off film 110 is fixed in the lens barrel 621; the sensor 510 is disposed at the bottom of the lens barrel 621, opposite to the lens 622.

In practical application, the infrared cut-off film 110 may be integrated in the lens 620, and in the manufacturing process of the lens 620, the infrared cut-off film 110 is assembled in the lens barrel 621 of the lens 620 by a direct mounting process, so that the assembly process steps of the electronic device 600 are simplified, the assembly cost is reduced, the attachment precision of the infrared cut-off film 110 is improved, and the yield of the electronic device 600 is improved.

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 glue.

Next, an embodiment of the present application further provides a method for manufacturing a filter, which is used to manufacture the filter in the foregoing embodiment. Referring to fig. 16, fig. 16 is a flowchart illustrating a method for fabricating a filter according to an embodiment of the present disclosure, where the method for fabricating a filter includes the following steps:

step S1601: an infrared cut film is prepared on the upper surface of the target substrate.

Step S1602: and the thickness of the first target area in the infrared cut-off film is adjusted to obtain the red light filtering unit.

Specifically, the infrared cut film may be first prepared on the upper surface of the target substrate, wherein the infrared cut film may be prepared by coating the sub-film layer (described in the above embodiments) layer by layer. Then, the thickness of the partial region in the infrared cut film is adjusted to obtain the red light filtering unit, so that the red light filtering unit can make part or all of the red light signal pass through.

For the above step S1601, as an embodiment, the target substrate may be a sensor, the sensor includes a photosensitive pixel array, the photosensitive pixel array includes a plurality of photosensitive cells, and the first target area is an area corresponding to one or more photosensitive cells. The film thus obtained is the filter shown in FIG. 2. Therefore, the infrared cut film can be prepared on the upper surface of the sensor.

As another embodiment, the target substrate may be a substrate disposed above the sensor, the sensor includes a photosensitive pixel array including a plurality of photosensitive cells, and the first target region is a region corresponding to one or more photosensitive cells. The filter shown in fig. 10 was obtained. Therefore, the infrared cut film can be prepared on the upper surface of the substrate, and the substrate is positioned above the sensor, so that the lens-type fingerprint identification device can be realized based on the optical filter.

As an implementation manner for the step S1602, the step S1602 may specifically include the following steps:

and thinning the first target area in the infrared cut-off film to obtain a red light filtering unit.

Taking the infrared cut-off film multilayer sub-film layer as an example, the method for preparing the filter film provided by the embodiment of the present application may include the following steps:

in the first step, a multilayer sub-film layer is prepared on the upper surface of a target substrate.

And secondly, removing redundant sub-film layers in a first target area in the multi-layer sub-film layers to obtain a red light filtering unit.

Corresponding to the arrangement of the filter units of other color lights in the filter film shown in fig. 3, after step S1602, the method for manufacturing a filter film provided in the embodiment of the present application may further include the following steps:

and step one, reducing the thickness of a second target area in the infrared cut-off film to obtain a filling groove.

And secondly, adding a filter material into the filling groove to obtain a filter unit of light of other colors except the red light.

Corresponding to the arrangement of the filter units for other color lights in the filter shown in fig. 4, before step S1601, the method for manufacturing a filter provided in the embodiment of the present application may further include the following steps:

and a filter unit for adding filter material on the upper surface of the sensor to obtain light of other colors except red light.

Corresponding to the above-mentioned arrangement manner of the filter units of the other color lights in the filter film shown in fig. 5, after step S1602, the method for manufacturing a filter film provided in the embodiment of the present application may further include the following steps:

and a filter unit for adding filter material on the upper surface of the infrared cut-off film to obtain light of other colors except red light.

Corresponding to the arrangement of the filter units for other color lights in the filter shown in fig. 11, before step S1601, the method for manufacturing a filter film provided in the embodiment of the present application may further include the following steps:

and a filter unit for adding filter material on the upper surface of the substrate to obtain light of other colors except red light.

Therefore, the filter film can be provided with filter units corresponding to other color lights, so that the anti-counterfeiting performance of the fingerprint identification device for true and false fingerprints is further improved.

Further, in the above embodiment, the step of adding the filter material may specifically include the following steps:

the filter material is coated by adopting a material adding method, wherein the material adding method comprises a spraying or point coating method.

Therefore, the coating of the filter material is carried out by adopting a low-precision material addition method, the difficulty of the process is reduced, and the consumable material is reduced.

Finally, the embodiment of the application also provides a fingerprint anti-counterfeiting identification method, which is used for realizing the anti-counterfeiting identification of the fingerprint by using the filter film or the filter in the embodiment. Referring to fig. 17, fig. 17 is a flowchart of a fingerprint anti-counterfeit identification method according to an embodiment of the present disclosure, where the fingerprint anti-counterfeit identification method includes the following steps:

step S1701: and acquiring a light signal received by the photosensitive unit, wherein the light signal is received by the photosensitive unit after being filtered by a filter film or a filter unit in a filter.

Step 1702: and identifying the authenticity of the fingerprint according to the optical signal.

Therefore, when adopting the filter coating or the optical filter that this application embodiment provided, on adopting infrared cut-off membrane to realize the basis of preventing sunshine, can utilize the red light signal who passes through to realize distinguishing of true and false fingerprint to improve the fingerprint identification device who possesses the sun protection effect and to the anti-counterfeit performance of true and false fingerprint.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units is only one logical division, and there may be other divisions when actually implemented, and for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection of devices or units through some communication interfaces, and may be in an electrical, mechanical or other form.

In addition, units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

Furthermore, the functional modules in the 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.

It should be noted that the functions, if implemented in the form of software functional modules and sold or used as independent products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

In this document, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like 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, comprising:

the infrared cut-off film is internally provided with a red light filtering unit, and the red light filtering unit is used for passing part or all of red light signals;

wherein the red light filtering unit is obtained by adjusting the thickness of the infrared cut-off film.

2. The filter film of claim 1, wherein the infrared cut film comprises a plurality of sub-film layers, wherein the film layer of the red light filter unit is a partial sub-film layer of the plurality of sub-film layers, and the partial sub-film layer allows part or all of a red light signal to pass through.

3. The filter film of claim 2, wherein the red light filtering unit is obtained by removing an excess sub-film layer of the multi-layer sub-film layer, wherein the excess sub-film layer is the sub-film layer of the multi-layer sub-film layer except for the partial sub-film layer.

4. The filter film of any of claims 1-3, wherein the red light filtering unit is a groove distributed in the infrared cut film, wherein the groove allows part or all of the red light signal to pass through.

5. The filter film of any of claims 1-4, wherein the red light filtering unit is further configured to pass other light signals adjacent to the wavelength band of the red light signal.

6. The filter film of any one of claims 1-5, wherein a filter unit for light of a color other than the red light is further disposed in the filter film for passing light signals of the color other than the red light.

7. The film filter of claim 6, wherein the unit for filtering the other color light is obtained by filling a filter material in a filling unit included in the infrared cut film;

alternatively, the filter unit of the other color light is disposed on an outer surface of the infrared cut film.

8. The film filter of claim 7, wherein the filling unit comprises a filling groove disposed on an upper surface of the infrared cut film; and/or the presence of a gas in the gas,

the filling unit comprises a filling hole arranged on the lower surface of the infrared cut-off film.

9. The filter film of any one of claims 1 to 8, wherein part or all of the filter units are disposed in the edge region of the infrared cut film.

10. The filter of claim 9, wherein the edge region comprises four sub-regions;

the four sub-regions are symmetrically and adjacently arranged at four right angles of the infrared cut-off film.

11. An optical filter, comprising:

the film filter of any of claims 1-10;

the filter film is arranged on the upper surface of the substrate.

12. The utility model provides a fingerprint identification module which characterized in that includes:

the film filter of any of claims 1-10;

a sensor comprising a photosensitive pixel array comprising a plurality of photosensitive cells;

the filter film is arranged above the sensor, and the filter unit is arranged corresponding to the photosensitive unit in the sensor.

13. The fingerprint identification module of claim 12, wherein the filter is disposed on a photosensitive surface of the sensor.

14. The utility model provides a fingerprint identification module which characterized in that includes:

the optical filter of claim 11;

the optical filter is arranged above the sensor, and the optical filtering unit and the photosensitive unit in the sensor are correspondingly arranged.

15. A preparation method of a light filter film is characterized by comprising the following steps:

preparing an infrared cut-off film on the upper surface of a target substrate;

the thickness of a first target area in the infrared cut-off film is adjusted to obtain a red light filtering unit;

wherein, the red light filter unit makes part or all of the red light signal pass through.

16. The method of claim 15, wherein the step of adjusting the thickness of the first target region in the infrared cut film to obtain a red light filter unit comprises:

and thinning the first target area in the infrared cut-off film to obtain the red light filtering unit.

17. The method of claim 16, wherein the step of forming an infrared cut film on the upper surface of the target substrate includes:

preparing a multilayer sub-film layer on the upper surface of the target substrate;

the light filtering unit for obtaining the red light by thinning the first target area in the infrared cut-off film comprises:

and removing redundant sub-film layers in the first target area in the multilayer sub-film layers to obtain the red light filtering unit.

18. The method of any of claims 15-17, wherein the target substrate is a sensor, the sensor includes a photosensitive pixel array, and the photosensitive pixel array includes a plurality of photosensitive cells;

the first target region is a region corresponding to one or more photosensitive cells.

19. The method of any of claims 15 to 17, wherein the target substrate is a substrate disposed over a sensor, the sensor including a photosensitive pixel array including a plurality of photosensitive cells;

20. The method for preparing a filter film according to claim 19, wherein before the preparing the infrared cut film on the upper surface of the target substrate, the method further comprises:

and the light filtering unit is used for adding a light filtering material on the upper surface of the substrate to obtain light with other colors except the red light.

21. The method for producing a filter film according to claim 18 or 19, wherein before the producing the infrared cut film on the upper surface of the target substrate, the method further comprises:

and the filter unit is used for adding filter materials on the upper surface of the sensor to obtain light of other colors except the red light.

22. The method of claim 18 or 19, wherein after the step of adjusting the thickness of the first target region in the infrared cut film to obtain a red light filter unit, the method further comprises:

reducing the thickness of a second target area in the infrared cut-off film to obtain a filling groove; wherein the second target region is a region corresponding to one or more photosensitive cells;

and a filter unit for adding filter material into the filling groove to obtain light of other colors except red light.

23. The method for preparing a filter film according to any one of claims 15 to 19, wherein after the step of adjusting the thickness of the first target region in the infrared cut film to obtain a filter unit for red light, the method further comprises:

and the filtering unit is used for adding a filtering material on the upper surface of the infrared cut-off film to obtain light with other colors except the red light.

24. The method for preparing a filter film according to any one of claims 20 to 23, wherein the adding of filter materials comprises:

and coating the filter material by adopting a material adding method, wherein the material adding method comprises a spraying or point coating method.

25. A fingerprint anti-counterfeiting identification method is characterized by comprising the following steps:

acquiring a light signal received by a photosensing unit, wherein the light signal is received by the photosensing unit after passing through a filtering unit in a filter film according to any one of claims 1-10 or a filtering unit in a filter according to claim 11;

and identifying the authenticity of the fingerprint according to the optical signal.

26. An electronic device, comprising a display panel and the fingerprint recognition module of claim 12 or the fingerprint recognition module of claim 13 or 14;

the fingerprint identification module set up in display panel's below.