Collimation film and preparation method, fingerprint recognition module, display device, electronic equipment

Abstract

The present disclosure can provide a collimating film and a preparation method, a fingerprint recognition module, a display device, and an electronic device, wherein the collimating film includes: a shading film layer made of a non-light-transmitting material; a through hole, which is provided on the shading film layer; and a microlens, which is made of a first light-transmitting material and is embedded in the through hole. The preparation method of the collimating film is used to prepare the collimating film of the embodiment of the present disclosure, the fingerprint recognition module includes the collimating film, the display device includes the fingerprint recognition module, and the electronic device includes the display device. By embedding the microlens made of the first light-transmitting material in the through hole on the shading film layer made of a non-light-transmitting material, the thickness of the collimating film provided by the present disclosure is the thickness of the shading film layer, thereby achieving the purpose of effectively reducing the thickness of the collimating film, etc.

Description

Technical Field

[0001] The present disclosure relates to the field of fingerprint recognition technology. More specifically, the present disclosure can provide a collimating film and a preparation method thereof, a fingerprint recognition module, a display device, and an electronic device. Background Art

[0002] At present, under-screen fingerprint recognition technology has been applied to a large number of electronic devices, such as smartphones. Among them, the under-screen fingerprint recognition process may include: collecting the reflected light formed by the light emitted by the light source and emitted by the user's finger through the fingerprint recognition module, and the reflected light carries the fingerprint information of the finger, thereby realizing under-screen fingerprint recognition. In the under-screen fingerprint recognition process, the light emitted by the light source must form a collimated light path, so a collimating film must be equipped in the fingerprint recognition module. However, due to the technical limitations of the existing collimating film structure, the thickness of the collimating film is difficult to further reduce. Summary of the invention

[0003] To solve one or more problems existing in the prior art, the present disclosure provides a collimating film, including: a shading film layer made of a non-light-transmitting material; a through hole penetrated through the shading film layer; and a microlens made of a first light-transmitting material and embedded in the through hole.

[0004] To solve one or more problems existing in the prior art, the present disclosure provides a method for preparing a collimating film, comprising: providing a semiconductor substrate; forming a layer of non-light-transmitting material on the semiconductor substrate to obtain a light-shielding film layer; performing a first photolithography process on the light-shielding film layer to form a through hole on the light-shielding film layer; forming a microlens in the through hole, and the microlens is embedded in the through hole; the microlens is made of a first light-transmitting material.

[0005] To solve one or more problems existing in the prior art, the present disclosure provides a fingerprint recognition module, comprising: the alignment film in any embodiment of the present disclosure; and a plurality of fingerprint sensors, arranged below the alignment film, the plurality of fingerprint sensors corresponding one-to-one to the plurality of through holes.

[0006] To solve one or more problems existing in the prior art, the present disclosure can also provide a display device, including the fingerprint recognition module in any embodiment of the present disclosure.

[0007] To solve one or more problems existing in the prior art, the present disclosure can also provide an electronic device, including the display device in any embodiment of the present disclosure.

[0008] The beneficial effects of the present disclosure include: by embedding a microlens made of a first light-transmitting material in a through hole on a light-shielding film layer made of a non-light-transmitting material, the thickness of the collimating film provided by the present disclosure is the thickness of the light-shielding film layer, thereby achieving the purpose of effectively reducing the thickness of the collimating film. The thickness of the collimating film provided by the present disclosure can be reduced accordingly as the thickness of the light-shielding film layer decreases, and the thickness of the collimating film can be further reduced as the film material technology evolves. Compared with the structure in which the light-shielding film layer and the microlens are separately arranged, the collimating film provided by the present disclosure has the advantage of a smaller thickness, so that a smaller fingerprint recognition module can be provided, thereby providing technical support for the widespread application of under-screen fingerprint recognition technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of a structure for forming a layer of non-light-transmitting material on a semiconductor substrate in one or more embodiments of the present disclosure is shown.

[0010] Figure 2 A schematic diagram of a structure for forming a through hole on a light-shielding film layer in one or more embodiments of the present disclosure is shown.

[0011] Figure 3 A schematic diagram of a structure in which a transparent resin material is coated in a through hole in one or more embodiments of the present disclosure is shown.

[0012] Figure 4 A schematic structural diagram of a collimating film including a light-shielding film layer, a microlens and a flat layer in one or more embodiments of the present disclosure is shown.

[0013] Figure 5 One or more embodiments of the present disclosure include Figure 4 Schematic diagram of the structure of the fingerprint recognition module with the collimating film in FIG.

[0014] Figure 6 One or more embodiments of the present disclosure include Figure 5 Schematic diagram of the structure of the display device of the fingerprint recognition module.

[0015] Figure 7 The user's finger and the Figure 6 Schematic diagram of the positional relationship of the display devices in FIG.

[0016] Figure 8 A schematic diagram showing the connection relationship between a fingerprint sensor and a mainboard of an electronic device in one or more embodiments of the present disclosure is shown.

[0017] In the figure,

[0018] 100, semiconductor substrate; 200, light-shielding film layer; 300, through hole; 301, transparent resin material; 302, microlens; 400, flat layer; 500, fingerprint sensor; 600, infrared cutoff layer; 700, flexible support film; 800, flexible substrate; 900, display screen; 901, finger; 501, driver integrated circuit; 502, flexible circuit board; 503, chip-on-film. DETAILED DESCRIPTION

[0019] The present disclosure is further described in detail below in conjunction with the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are only used to explain the present disclosure, rather than to limit the present disclosure. It should also be noted that, for ease of description, only some structures related to the present disclosure are shown in the accompanying drawings, rather than all structures. In the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Various structural schematic diagrams according to embodiments of the present disclosure are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified for the purpose of clear expression, and some details may be omitted. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships between them are only exemplary, and may be deviated due to manufacturing tolerances or technical limitations in practice, and those skilled in the art may additionally design regions / layers with different shapes, sizes, and relative positions according to actual needs. In the context of the present disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or there may be an intermediate layer / element between them. In addition, if one layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0020] The collimating film in at least one embodiment of the present disclosure, for example Figure 4 As shown in Figure 5, the collimating film may include but is not limited to a shading film layer 200, a through hole 300 and a microlens 302. The shading film layer 200 is made of a non-light-transmitting material, and the through hole 300 is provided on the shading film layer 200; the microlens 302 is made of a first light-transmitting material and is embedded in the through hole 300. Compared with the conventional collimating film with a larger thickness, the embodiment of the present disclosure embeds a microlens made of a first light-transmitting material in a through hole on a shading film layer made of a non-light-transmitting material. The thickness of the collimating film provided by the present disclosure is the thickness of the shading film layer, thereby effectively reducing the thickness of the collimating film. The thickness of the collimating film provided by the present disclosure can be reduced accordingly as the thickness of the shading film layer decreases, and the thickness of the collimating film can be further reduced as the film material technology evolves. Compared with the structure in which the shading film layer and the microlens are separately provided, the collimating film provided by the present disclosure has the advantage of a smaller thickness, and thus can provide a fingerprint recognition module with a smaller size. The collimating film provided by the embodiment of the present disclosure not only has the characteristic of being thin, but also can effectively utilize the shading film layer to block stray light and effectively enhance the utilization efficiency of effective light.

[0021] In at least one embodiment of the present disclosure, Figures 4 to 7 As shown, the collimating film may further include a flat layer 400, which is made of a second light-transmitting material and is formed in the through hole 300; the flat layer 400 and the microlens 302 in the embodiment of the present disclosure fill the through hole 300 together. Thus, the microlens 302 and the flat layer 400 are used to form an optical path structure of the fingerprint recognition module. The flat layer provided in the embodiment of the present disclosure can be filled in the gap between the microlens 302 and the display screen 900 to further ensure that the light reaches the display screen in a collimated manner.

[0022] The collimating film involved in at least one embodiment of the present disclosure comprises a plurality of through holes 300 formed on the light-shielding film layer 200 to form a hole array, and a plurality of microlenses 302 corresponding to the plurality of through holes 300 to form a lens array. The lens array in the hole array and the corresponding flat layer 400 together form a complete optical path structure, wherein two or more adjacent through holes 300 may have the same distance, and the hole array may be uniformly opened on the light-shielding film layer 200 in a honeycomb shape or a queue shape. The shape of the hole array is of course not limited to the above-mentioned examples, and is subject to the ability to achieve the technical purpose of the present disclosure. It can be seen that the plurality of microlenses 302 corresponding to the plurality of through holes 300 in the embodiment of the present disclosure are inlaid one by one in the plurality of through holes 300 included in the hole array, and the plurality of microlenses 302 can further improve the light transmission rate, so as to help obtain more and more comprehensive fingerprint information, thereby improving the recognition effect of the fingerprint under the screen and enhancing the user experience.

[0023] In at least one embodiment of the present disclosure, the axial direction of the through hole 300 on the light shielding film layer 200 is perpendicular to the extension direction of the light shielding film layer 200. The axial direction of the through hole 300 can be, for example, a vertical direction, and the extension direction of the light shielding film layer 200 can be, for example, a horizontal direction. Based on this, the present disclosure can form an optical path structure along the vertical direction, so that the light emitted by the light source used in the fingerprint recognition module can be emitted to the screen along the vertical direction and generate reflected light along the vertical direction, further improving the effect of fingerprint recognition.

[0024] In one or more embodiments of the present disclosure, the first light-transmitting material is a transparent resin material, and the second light-transmitting material is a translucent resin material. In the embodiments of the present disclosure, the microlenses 302 are made of a transparent resin material, and the flat layer 400 is made of a translucent resin material, so that a lens array formed by a plurality of microlenses 302 and a flat layer 400 disposed on the lens array form a collimated light path structure, so as to ensure that the light emitted by the light source is only propagated from the collimated light path structure, thereby improving the collimation effect of the light.

[0025] In one or more embodiments of the present disclosure, the refractive index of the flat layer 400 is less than the first preset refractive index, the refractive index of the microlens 302 is greater than the second preset refractive index, and the second preset refractive index is greater than the first preset refractive index. The transparent resin material 301 in one or more embodiments of the present disclosure may be a high refractive index transparent resin material, and the translucent resin material may be a low refractive index light-transmitting resin material. Optionally, the first preset refractive index is, for example, greater than or equal to 1.5, and the second preset refractive index is, for example, less than or equal to 0.8, but it is certainly not limited thereto. In the embodiments of the present disclosure, the microlens 302 made of a high refractive index transparent resin material and the flat layer 400 made of a low refractive index light-transmitting material together form an optical path structure, which can not only ensure that the light is transmitted along the collimation direction, but also ensure the compactness of the overall structure of the collimating film.

[0026] In at least one embodiment of the present disclosure, the non-light-transmissive material is a black light-shielding resin material. It can be seen that the present disclosure realizes the structure of microlens plus light-shielding resin material for collecting fingerprint optical information. The black light-shielding resin material can further improve the effect of blocking stray light, ensure that only the required collimated light is allowed to pass through the microlens and the flat layer of the collimating film, and improve the light-shielding effect of the light-shielding film layer 200. The light-shielding film layer 200 made of black light-shielding resin material in the embodiment of the present disclosure has the advantage of improving the fingerprint recognition effect.

[0027] Based on the same inventive technical concept as the collimating film provided in the embodiments of the present disclosure, one or more embodiments of the present disclosure can also provide a method for preparing the collimating film, which may include but is not limited to at least one of the following steps.

[0028] First, a semiconductor substrate 100 is provided. The semiconductor substrate 100 in the embodiment of the present disclosure includes at least one of a silicon substrate, a germanium substrate, and a silicon germanium substrate. Of course, the substrate is selected based on the processing purpose of the light shielding film layer 200 in the embodiment of the present disclosure, and is removed after the alignment film processing is completed.

[0029] Secondly, combined Figure 1 As shown, a layer of non-light-transmitting material is formed on the semiconductor substrate 100 to obtain a light-shielding film layer 200 before the through hole 300 is opened. The non-light-transmitting material of at least one embodiment of the present disclosure is a black light-shielding resin material. By preparing a layer of black light-shielding resin material as the light-shielding film layer 200, the light-shielding film layer 200 formed by the black light-shielding resin material will have a better effect of shielding stray light, thereby improving the light collimation effect of the collimating film of the present disclosure.

[0030] Again, if Figure 2 As shown, the light shielding film layer 200 is subjected to a first photolithography process to form a through hole 300 on the light shielding film layer 200. When the present embodiment is implemented, a plurality of through holes 300 can be formed on the light shielding film layer 200 through the first photolithography process, and the plurality of through holes 300 formed on the light shielding film layer 200 form a hole array. It can be seen that the present disclosure forms a hole region on a layer of black light shielding resin material through a photolithography process, and the hole region is the hole array composed of a plurality of through holes 300 in the present embodiment. In at least one embodiment of the present disclosure, the axial direction of the through hole 300 is perpendicular to the extension direction of the light shielding film layer 200, so that the light emitted by the light source can be emitted in a direction perpendicular to the extension direction of the light shielding film layer 200, further ensuring the light collimation effect. In addition, based on the technical solution of the present disclosure, the method of forming the through hole 300 on the light shielding film layer 200 is not limited to the photolithography process, and other processes such as etching processes for forming a plurality of through holes 300 on the light shielding film layer 200 can also be used. It should be understood that the detailed photolithography process details such as the mask, photoresist coating, alignment, etc. used in the first photolithography process can be reasonably selected according to actual conditions and will not be described in detail in this embodiment.

[0031] Finally, if Figure 3 and Figure 4 As shown, a micro lens 302 is formed in the through hole 300, and the micro lens 302 is embedded in the through hole 300; the micro lens 302 is made of a first light-transmitting material. Figure 4 After preparing the collimating film, remove Figure 4 The semiconductor substrate 100 is then transferred to the prepared alignment film onto the infrared cut-off layer 600 which has been prepared in advance. Figure 5As shown, the following content will further explain the product structure of the fingerprint recognition module including the infrared cutoff layer 600. In the embodiment of the present disclosure, a plurality of microlenses 302 corresponding to a plurality of through holes 300 can form a lens array, that is, each microlens 302 in the lens array is respectively embedded in each through hole 300 in the hole array. In at least one embodiment of the present disclosure, the first light-transmitting material is a transparent resin material, that is, the microlens in this embodiment is made of a transparent resin material. It can be seen that one or more embodiments of the present disclosure can realize the preparation of an ultra-thin collimating film, so that a fingerprint recognition module with a smaller thickness can be prepared.

[0032] like Figure 4 As shown, in one or more embodiments of the present disclosure, the method for preparing the collimating film further includes: forming a flat layer 400 in the through hole 300, so that the flat layer 400 and the microlens 302 fill the through hole 300 together; the flat layer 400 is made of a second light-transmitting material.

[0033] In at least one embodiment of the present disclosure, the first light-transmitting material is a transparent resin material 301, and the second light-transmitting material is a translucent resin material. Among them, the refractive index of the flat layer 400 may be less than the first preset refractive index, the refractive index of the microlens 302 is greater than the second preset refractive index, and the second preset refractive index is greater than the first preset refractive index. The transparent resin material 301 of the embodiment of the present disclosure is a high-refractive-index transparent resin material, and the translucent resin material is a low-refractive-index light-transmitting material. The first preset refractive index is, for example, greater than or equal to 1.5, and the second preset refractive index is, for example, less than or equal to 0.8, but of course it is not limited thereto. It can be seen that the embodiment of the present disclosure forms an optical path structure through microlenses made of high-refractive-index resin materials and a flat layer made of low-refractive-index light-transmitting materials, which can help reduce the thickness of the collimating film structure while ensuring that the light path is transmitted along the collimating direction.

[0034] like Figure 3 and Figure 4As shown, at least one embodiment of the present disclosure forms a microlens 302 in a through hole 300, including: applying a layer of transparent resin material 301, the transparent resin material 301 fills the through hole 300, and the position of the through hole 300 is filled; a grayscale mask is placed above the layer of transparent resin material 301, and a second photolithography process is performed on the layer of transparent resin material 301 to form a microlens 302 in the through hole 300. It can be seen that the embodiment of the present disclosure uses grayscale mask photolithography technology to prepare a microlens 302 structure in each through hole 300, the microlens 302 is embedded in the black light-shielding resin, and the grayscale mask has a preset pattern for forming the microlens 302, and after the second photolithography process, a mechanochemical flattening process is performed to remove the transparent resin material remaining on the upper surface of the light-shielding film layer 200, so as to ensure that the transparent resin material is only used to form the microlens 302, that is, only the transparent resin material for forming the microlens 302 is left in each through hole 300. Similarly, in the process of forming the flat layer 400, after coating the second light-transmitting material, the second light-transmitting material is present in the through hole 300 and on the upper surface of the light-shielding film layer 200. The present embodiment can also remove the second light-transmitting material on the upper surface of the light-shielding film layer 200 by chemical mechanical flattening, thereby forming a flat layer 400 in each through hole 300; of course, removing the second light-transmitting material on the upper surface of the light-shielding film layer 200 is not limited to the above method, so as to achieve the purpose of preparing the flat layer 400 disclosed in the present invention.

[0035] like Figure 5 As shown, based on the same inventive technical concept as the collimating film in the embodiment of the present disclosure, at least one embodiment of the present disclosure can also provide a fingerprint recognition module, which includes the collimating film in at least one embodiment of the present disclosure and multiple fingerprint sensors 500, wherein the multiple fingerprint sensors 500 are arranged under the collimating film, and the multiple fingerprint sensors 500 correspond to the multiple through holes 300 one by one, that is, each fingerprint sensor 500 included in the fingerprint recognition module corresponds to each through hole 300 in the hole array one by one. It should be understood that the fingerprint sensor 500 in the embodiment of the present disclosure is an optical sensor for collecting reflected light formed by the light emitted by the light source and emitted by the user's finger.

[0036] like Figure 6 As shown, and can be combined Figure 5, the fingerprint recognition module in one or more embodiments of the present disclosure may also include an infrared cutoff layer 600, which is disposed between the fingerprint sensor 500 and the collimating film. The infrared cutoff layer 600 is disposed below the collimating film, and the infrared cutoff layer 600 can be used to absorb infrared light, thereby avoiding the influence of infrared signals in the light on the fingerprint recognition result; the infrared cutoff layer 600 in this embodiment is attached to each fingerprint sensor 500, and there is no other auxiliary structure between the infrared cutoff layer 600 and the fingerprint sensor 500, so that the fingerprint recognition module structure of this embodiment is more compact. The infrared cutoff layer 600 in the embodiment of the present disclosure is directly attached to the collimating film, which can not only further reduce the thickness of the fingerprint recognition module, but also the present embodiment can effectively omit the structure composed of OCA (Optically Clear Adhesive) or other glue used in conventional solutions for bonding the collimating film and the infrared cutoff layer 600.

[0037] like Figure 6 As shown, and can be combined Figure 7 , the fingerprint recognition module in at least one embodiment of the present disclosure also includes a flexible support film 700, which can be well used in a flexible display device, and a groove is provided on the flexible support film 700; the collimating film, the infrared cut-off layer 600 and the sensor are all arranged in the groove. The flexible support film 700 can be made of at least one of a stainless steel material, a carbon fiber material and a titanium alloy material. The embodiment of the present disclosure can form a groove on the flexible support film 700 by a carbon dioxide laser or other equipment with a surface groove processing function, and the groove is used to reserve a position and space for the fingerprint recognition module to place the fingerprint recognition module. Among them, the stainless steel material in at least one embodiment of the present disclosure can be, for example, SUS (Steel Use Stainless, steel uses stainless steel) stainless steel material. Based on the above-mentioned fingerprint recognition module structure, the fingerprint recognition module prepared in the embodiment of the present disclosure can be directly attached to the bottom of the display screen 900, and the flexible support film 700 is attached to the flexible substrate 800 and the bottom of the display screen 900. It can be seen that the embodiment of the present disclosure can be better applied to the flexible display device and can reduce costs.

[0038] like Figure 6 As shown, and can be combined Figure 5 and Figure 7, the fingerprint recognition module in at least one embodiment of the present disclosure also includes a flexible substrate 800, which is arranged in the groove and formed under the sensor. The collimating film, infrared cutoff layer 600 and each fingerprint sensor 500 in this embodiment are prepared on a flexible substrate to be more suitable for flexible display devices such as folding screens. The flexible substrate 800 in the embodiment of the present disclosure can be made of at least one material of polyimide (PI), NOA (norland optical adhesive) or SU8 (aromatic compound) photoresist, so the fingerprint recognition module provided by the embodiment of the present disclosure can be better used in a flexible display device. Combined with Figure 6 and Figure 5 As shown, in the groove of the flexible support film 700 in the embodiment of the present disclosure, the flexible substrate 800 and each fingerprint sensor 500 may be filled with the same material as the flexible substrate 800 and may be integrated with the flexible substrate 800. The filled material may be, for example, at least one of imide, NOA or SU8 photoresist, but is certainly not limited thereto.

[0039] One or more embodiments of the present disclosure can provide a display device, which includes but is not limited to the fingerprint recognition module in any embodiment of the present disclosure. The display device may also include a display screen 900, and the fingerprint recognition module may be arranged in a local area below the display screen 900, or the fingerprint recognition module may be arranged in the entire area below the display screen 900, thereby forming a display device with an under-screen fingerprint recognition function, such as a display device with a partial under-screen fingerprint recognition function or a display device with a full-screen fingerprint recognition function. Among them, the structure of the fingerprint recognition module of this embodiment has been described in detail in this specification and will not be repeated here.

[0040] like Figure 7As shown, taking the fingerprint recognition module set in the local area below the display screen 900 as an example, when the user's finger 901 is placed on the display screen 900, specifically when the user's finger 901 is placed in the screen fingerprint recognition area corresponding to the fingerprint recognition module, the light source is reflected at the user's finger 901 through the collimating film and the screen 900 provided in the embodiment of the present disclosure, forming reflected light, and then the reflected light is obtained by the fingerprint sensor of the fingerprint recognition module to collect the fingerprint information of the finger 901. Among them, the display device in the embodiment of the present disclosure also includes a light source, and the light emitted by the light source passes through the infrared cut-off layer 600, the microlens 302 and the flat layer 400, and then projects onto the user's finger 901. The fingerprint recognition module collects the reflected light after the user's finger 901 is reflected, passes through the flat layer 400, the microlens 302 and the infrared cut-off layer 600, and reaches the fingerprint sensor 500, and then performs fingerprint recognition through the fingerprint information contained in the reflected light. The judgment method or algorithm used in the fingerprint recognition process can be reasonably selected according to actual needs, and this embodiment will not be repeated.

[0041] like Figure 8 As shown, and can be combined Figure 7 and Figure 6 , the fingerprint recognition module is arranged below the display screen 900, and the display device may further include a driver integrated circuit (IC) 501, a flexible printed circuit (FPC) 502, and a chip on FPC (COF) 503. The fingerprint sensor 500 included in the fingerprint recognition module is connected to the driver integrated circuit 501 through the chip on FPC 503, and the driver integrated circuit 501 is also connected to the flexible printed circuit 502 through the chip on FPC 503, that is, the fingerprint sensor 500, the driver integrated circuit 501, and the flexible printed circuit 502 are connected through the chip on FPC 503, wherein the flexible printed circuit 502 can be used to connect to the mainboard of the electronic device. The display screen 900 in one or more embodiments of the present disclosure is, for example, an OLED (Organic Light-Emitting Diode), a MicroLED (Micro Light Emitting Diode), a Miniled (Mini Light Emitting Diode), etc. The relevant structure of the display device for realizing the display function and the connection relationship with the fingerprint recognition module can be reasonably selected according to the actual needs of the display device or electronic device based on at least one embodiment of the present disclosure.

[0042] In an example of the present disclosure, the display device includes a folding screen, and of course also includes a non-folding screen. It can be seen that the embodiment of the present disclosure can provide a fingerprint recognition solution under a folding screen. For the fingerprint recognition solution under the folding screen, taking the OLED screen as an example, the OLED screen must be attached to the support layer formed by the SUS stainless steel material to achieve the purpose of reducing the crease phenomenon of the folding screen, but the support layer formed by the SUS stainless steel material cannot be punched, so the conventional fingerprint recognition module with a larger thickness cannot be applied to the folding screen, and only a more expensive material can be selected to make the support layer. Compared with the solution of selecting a more expensive material to make the support layer, one or more embodiments of the present disclosure provide a thinner collimating film and a thinner fingerprint recognition module, so the present disclosure only needs to open a groove on the support layer, so the support layer formed by the SUS stainless steel material can be used in the folding screen solution based on the present disclosure. The present disclosure can realize the structure and function of optical fingerprint recognition under the folding screen, and greatly improve the product experience of the display device under the premise of reducing the thickness of the fingerprint recognition module and not affecting the bending effect.

[0043] One or more embodiments of the present disclosure can also provide an electronic device, which includes but is not limited to the display device in any embodiment of the present disclosure, and the display device includes the fingerprint recognition module provided in any embodiment of the present disclosure. The display device provided by the embodiments of the present disclosure includes but is not limited to the following categories: smart phones, smart watches, tablet computers, laptops, desktop displays, televisions, digital cameras, smart bracelets, smart glasses, car displays, medical equipment, industrial control equipment and touch interactive terminals, etc. The technical solutions provided by the embodiments of the present disclosure can be applied to a variety of product scenarios.

[0044] In the description of this specification, the description of reference terms such as "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction. In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the above description, the technical details of the patterning and etching of each layer are not described in detail. However, those skilled in the art should understand that various technical means can be used to form layers, regions, etc. of desired shapes. In addition, in order to form the same structure, those skilled in the art can also design methods that are not completely the same as the methods described above. In addition, although the various embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage.

[0046] The above are only preferred embodiments of the present disclosure and the technical principles used. Those skilled in the art will understand that the present disclosure is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present disclosure. Therefore, although the present disclosure is described in more detail through the above embodiments, the present disclosure is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present disclosure, and the scope of protection of the present disclosure is determined by the scope of the attached claims.

Claims

1. A collimating film, characterized in that: include: The light-shielding film layer is made of a non-light-transmitting material, and the thickness of the light-shielding film layer is the thickness of the collimating film; A through hole formed by performing a first photolithography process on the light-shielding film layer is penetrated on the light-shielding film layer, and a plurality of the through holes formed on the light-shielding film layer form a hole array; A microlens formed by performing a second photolithography process on the first light-transmitting material filled in the through hole is embedded in the through hole, and a plurality of microlenses corresponding to a plurality of the through holes form a lens array; A flat layer filling the through hole together with the micro lens, made of a second light-transmitting material, and formed in the through hole; The lens array in the hole array and the corresponding flat layer together form a complete optical path structure. The light emitted by the light source passes through the infrared cutoff layer, the microlens and the flat layer and is projected onto the user's finger. The infrared cutoff layer is directly bonded to the collimating film.

2. The collimating film according to claim 1, characterized in that The axial direction of the through hole is perpendicular to the extending direction of the light shielding film layer.

3. The collimating film according to claim 1, characterized in that The refractive index of the flat layer is less than a first preset refractive index, the refractive index of the microlens is greater than a second preset refractive index, and the second preset refractive index is greater than the first preset refractive index.

4. The collimating film according to claim 1, characterized in that The non-light-transmitting material is a black light-shielding resin material.

5. The collimating film according to claim 1, characterized in that The first light-transmitting material is a transparent resin material.

6. The collimating film according to claim 1, characterized in that The second light-transmitting material is a translucent resin material.

7. A method for preparing a collimating film, characterized in that: include: providing a semiconductor substrate; forming a layer of non-light-transmitting material on the semiconductor substrate to obtain a light-shielding film layer, wherein the thickness of the light-shielding film layer is the thickness of the collimating film; Performing a first photolithography process on the light-shielding film layer to form a through hole on the light-shielding film layer, wherein the through hole penetrates the light-shielding film layer, and a plurality of the through holes formed on the light-shielding film layer form a hole array; Forming a microlens in the through hole includes: coating a layer of transparent resin material, wherein the transparent resin material fills the through hole; A grayscale mask is placed above the layer of transparent resin material, and a second photolithography process is performed on the layer of transparent resin material to form a microlens in the through hole; the microlens is embedded in the through hole; the microlens is made of a first light-transmitting material, and a plurality of microlenses corresponding to a plurality of the through holes one by one form a lens array; A flat layer is formed in the through hole, so that the flat layer and the microlens fill the through hole together, and the flat layer is made of a second light-transmitting material; the lens array in the hole array and the corresponding flat layer together constitute a complete optical path structure, and the light emitted by the light source passes through the infrared cutoff layer, the microlens and the flat layer and is projected onto the user's finger, and the infrared cutoff layer is directly bonded to the collimating film.

8. The method for preparing a collimating film according to claim 7, characterized in that: The first light-transmitting material is a transparent resin material.

9. The method for preparing a collimating film according to claim 7, characterized in that: The non-light-transmitting material is a black light-shielding resin material.

10. A fingerprint recognition module, characterized in that: include: The collimating film according to any one of claims 1 to 6; A plurality of fingerprint sensors are arranged below the alignment film, and the plurality of fingerprint sensors correspond to the plurality of through holes one by one.

11. The fingerprint recognition module according to claim 10, characterized in that: Also includes: The infrared cut-off layer is arranged between the fingerprint sensor and the collimating film.

12. The fingerprint recognition module according to claim 11, characterized in that: Also includes: A flexible supporting film, wherein a groove is formed on the flexible supporting film; The collimating film, the infrared cut-off layer and the sensor are all arranged in the groove.

13. The fingerprint recognition module according to claim 12, characterized in that: Also includes: The flexible substrate is disposed in the groove and formed below the sensor.

14. The fingerprint recognition module according to claim 12 or 13, characterized in that: The flexible supporting membrane is made of at least one of stainless steel, carbon fiber and titanium alloy.

15. A display device, characterized in that: The invention comprises a fingerprint recognition module as described in any one of claims 11 to 14.

16. The display device according to claim 15, characterized in that: The display device includes a folding screen.

17. An electronic device, characterized in that: A display device comprising any one of claims 15 to 16.

Images