WO2021169725A1 - 一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组 - Google Patents

一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组 Download PDF

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WO2021169725A1
WO2021169725A1 PCT/CN2021/074315 CN2021074315W WO2021169725A1 WO 2021169725 A1 WO2021169725 A1 WO 2021169725A1 CN 2021074315 W CN2021074315 W CN 2021074315W WO 2021169725 A1 WO2021169725 A1 WO 2021169725A1
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collimating
layer
light
film
hole
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PCT/CN2021/074315
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English (en)
French (fr)
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唐海江
夏寅
高斌基
付坤
刘建凯
王小凯
李刚
张彦
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宁波激智科技股份有限公司
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Priority claimed from CN202011528176.6A external-priority patent/CN113376848B/zh
Application filed by 宁波激智科技股份有限公司 filed Critical 宁波激智科技股份有限公司
Publication of WO2021169725A1 publication Critical patent/WO2021169725A1/zh

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    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/30—Collimators

Definitions

  • the invention belongs to the field of image recognition, and in particular relates to a collimating film, an interference-reducing collimating film and a preparation method thereof, a laminating collimating film, and an image recognition module.
  • collimating devices In the field of image recognition, commonly used image sensors such as CMOS type or photo-TFT type, sensor modules generally contain collimating devices to enhance the signal-to-noise ratio, improve the recognition rate, and reduce crosstalk.
  • the function of the collimating device is mainly to collimate and filter the diffused light at a single point pixel of the image, and the normal collimated light or light (signal) that is close to collimation can be smoothly transmitted to At the corresponding photoelectric sensor, the large-angle light (noise) that deviates from the normal direction can only seldom or even not enter the non-corresponding photoelectric sensor, so the signal-to-noise ratio is enhanced.
  • Collimation devices usually have a top collimation structure layer and a bottom collimation structure layer:
  • the top and bottom double-layer collimation structures need to be accurately aligned, otherwise the signal light intensity will be greatly reduced (as shown in Figure 2);
  • Traditional collimating devices are generally rigid collimating plates, such as optical fiber bundle slices, or microlens and collimating diaphragms formed on both sides of the glass substrate.
  • Such rigid collimating plates generally need to be kept high. Thickness, on the one hand, is used to maintain the aspect ratio, on the other hand, it is used to maintain its mechanical properties and prevent breakage in the application environment.
  • this type of rigid collimator still cannot meet the application of large-size image recognition modules.
  • the overall thickness needs to be compressed such as ultra-thin large-screen mobile phones
  • it will become more brittle, more fragile, and lower production yield. Both performance and cost cannot meet the demand.
  • It is also obvious that such rigid collimating sheets are even less likely to be used in flexible image recognition modules.
  • the traditional rigid collimating sheet has high thickness, fragile and poor performance in the case of low thickness, the two-layer collimating structure (collimating diaphragm) is difficult to align, low yield, and low productivity. Large-size, ultra-thin, flexible image recognition applications.
  • the present invention provides a collimating film, an interference reducing collimating film and a preparation method thereof, a laminated collimating film and An image recognition module.
  • the collimating film provided by the present invention only includes one layer of collimating holes, which solves the problem of difficult alignment of two layers of collimating diaphragms.
  • the interference reducing collimating film provided by the present invention can reduce the phenomenon of light interference and improve the accuracy of image recognition.
  • the present invention adopts the following technical solutions:
  • the present invention provides a collimating film, which in turn includes a collimating lens layer, a flexible substrate layer and a collimating hole layer.
  • the collimating hole layer is a collimating diaphragm.
  • the collimating film provided by the present invention only includes one layer of collimating diaphragm.
  • the collimation film provided by the present invention only includes a layer of collimation holes.
  • the collimating film sequentially includes a collimating lens layer, a flexible substrate layer and a layer of collimating holes.
  • the collimating lens layer is placed on the upper surface of the flexible substrate, and the collimating hole layer is placed on the lower surface of the flexible substrate.
  • the collimating lens layer includes a microlens array and is thick.
  • the collimating hole layer includes an array of collimating holes.
  • the collimating hole layer includes a light-shielding medium layer and a collimating hole array.
  • the collimating hole layer includes a light-shielding medium and a collimating hole array formed by hollowing out the medium.
  • each collimating hole is on the main optical axis of the corresponding microlens. Further, the center of each collimating hole is on the main optical axis of the corresponding micro lens.
  • the collimating film is perforated by the micro-focusing method, the distribution of the collimating hole array and the micro lens array are exactly the same, the center of any collimating hole is on the main optical axis of the corresponding micro lens, one-to-one high-precision alignment , Alignment deviation ⁇ 1 ⁇ m.
  • the thickness T of the flexible base layer is selected from 10-50 ⁇ m, preferably 25-38 ⁇ m.
  • the micro lens arrays of the collimating lens layer are arranged in an orderly manner.
  • the aforementioned collimating film is called an ordered collimating film (also called an ordered collimating structure).
  • the aforementioned orderly arrangement is characterized in that the distance P between the main optical axes of adjacent microlenses is a constant value.
  • the microlens array of the collimating lens layer and the collimating hole array of the collimating hole layer are arranged in an orderly manner.
  • the aforementioned collimating film is called an ordered collimating film (also called an ordered collimating structure).
  • the microlens array of the collimating lens layer is arranged in disorder.
  • the collimating film in which the microlens array is arranged in disorder is called the interference-reducing collimating film (also called the disordered collimating structure, or the disordered array collimating film).
  • the aforementioned disordered arrangement is characterized in that the pitch P between the main optical axes of adjacent microlenses is a value that varies within a range.
  • the interference reduction collimation film can reduce the phenomenon of light interference and improve the accuracy of image recognition (recognition rate).
  • microlens array of the collimating lens layer and the collimating hole array of the collimating hole layer are arranged in disorder.
  • the aforementioned collimating film is called an interference-reducing collimating film (also called a disordered collimating structure).
  • Non-equilibrium triangles are also called ordinary triangles, which refer to triangles other than triangles whose three angles are all 60 degrees.
  • One collimating hole in the collimating hole array corresponds to a position of a micro lens in the micro lens array, and the main optical axis of the micro lens coincides with the center of the collimating hole or the deviation is less than 1 ⁇ m.
  • a micro lens corresponding to the position of a collimating hole is called the corresponding micro lens of the collimating hole.
  • the coordinates of the main optical axis of three adjacent microlenses are connected to form a regular triangle (composed of the main optical axis coordinates of three overlapping microlenses), or the main optical axis of four adjacent microlenses
  • the coordinates of are connected to form a square (connected by the coordinates of the main optical axis of four overlapping microlenses).
  • microlenses in the microlens array are closely arranged. That is, adjacent microlenses are in contact with each other or overlap each other.
  • the collimating lens array and the collimating hole array of the collimating film are both equilateral triangles (connected by the main optical axis coordinates of three overlapping microlenses) closely arranged, or square (comprised of four overlapping each other).
  • the main optical axis coordinates of the microlenses are connected) closely arranged.
  • the distance P between the main optical axes of adjacent microlenses is 10-50 ⁇ m
  • the radius R of the microlenses is 6.1 ⁇ m-30.2 ⁇ m
  • the height H of the collimating lens layer is 1.1 ⁇ m.
  • the refractive index n1 of the collimating lens layer material is 1.4 to 1.6; in the flexible base layer, the thickness T of the flexible base layer is 10-50 ⁇ m, and the refractive index n2 of the flexible base layer material is 1.5 to 1.65; In the collimating hole layer, the thickness t of the collimating hole layer is 0.5-7 ⁇ m, and the diameter ⁇ of the collimating hole in the collimating hole array is 1-10 ⁇ m.
  • the main optical axis pitches P of adjacent microlenses are all the same, and P is selected from 10 to 50 ⁇ m, preferably 15 to 30 ⁇ m, and more preferably 18 to 25 ⁇ m.
  • the microlenses of the collimating film focus the vertically incident light to form a light spot with a diameter of D on the lower surface of the flexible base layer.
  • D is selected from 0.1 to 7.8 ⁇ m, preferably 0.5 to 4.9 ⁇ m, and more preferably 1 to 2 ⁇ m.
  • the spot diameter D consists of the radius of curvature R (spherical radius R) of the microlens, the refractive index n1, the thickness of the collimating lens layer H (the vertical distance from the apex of the microlens to the upper surface of the substrate) and the refractive index n2 of the flexible substrate layer. T is jointly determined.
  • the radius of curvature R of the microlens is selected from 6.1 to 30.2 ⁇ m, and the thickness H of the collimating lens layer is selected from 1.1 to 27.4 ⁇ m.
  • R and H are not preferred, and adaptation is performed according to other parameters.
  • the refractive index n1 of the collimating lens layer (ie, the microlens layer) is selected from 1.4 to 1.6, preferably 1.5.
  • the refractive index n2 of the flexible base layer is selected from 1.5 to 1.65, which varies according to the material, and is not preferred, and ⁇ 0.02 errors caused by the same material and different processes are allowed.
  • the microlens array of the collimating film is made of the same thick material, and the material is all transparent polymer.
  • the transparent polymer of the microlens layer is selected from AR (Acrylic resin, acrylic resin or modified acrylic resin), PC (polycarbonate), PET (polyethylene terephthalate), PEN ( Polyethylene naphthalate), PI (polyimide), PS (polystyrene), SR (Silicon Resin), FEP (perfluoroethylene propylene copolymer) or EVA (ethylene-vinyl acetate) Copolymer). Further, it is preferably one of PMMA (polymethyl methacrylate), PC, or PS.
  • the flexible base layer of the collimating film is a transparent polymer film.
  • the material of the transparent polymer film is selected from PET, PEN, PI, PC, PMMA (polymethyl methacrylate), PP (polypropylene), PO (polyolefin), SR or COP (cycloolefin copolymer). One of the things). Further, it is preferably one of PET, PI, PC, or PMMA.
  • the light-shielding medium of the collimating hole layer of the collimating film is one or a combination of at least two of organic paint and inorganic coating.
  • the organic coating of the light-shielding medium is selected from an opaque polymer ink system.
  • the opaque polymer ink system includes a light-absorbing substance and a polymer curing system.
  • the light-absorbing material is selected from carbon (such as carbon black, carbon fiber, graphite, etc.), carbides (such as chromium carbide, titanium carbide, boron carbide, etc.), carbonitrides (such as titanium carbonitride, carbonitride, etc.) One or a combination of at least two of boron, etc.) and sulfides (such as ferrous sulfide, molybdenum disulfide, cobalt disulfide, nickel sulfide, etc.).
  • carbon such as carbon black, carbon fiber, graphite, etc.
  • carbides such as chromium carbide, titanium carbide, boron carbide, etc.
  • carbonitrides such as titanium carbonitride, carbonitride, etc.
  • sulfides such as ferrous sulfide, molybdenum disulfide, cobalt disulfide, nickel sulfide, etc.
  • the polymer curing system can be selected from acrylic system (AR), polyurethane system (PU), silicone resin system (SR), epoxy resin system (EP), melamine resin system (MF), phenolic resin system (PF), urea-formaldehyde resin system (UF), or thermoplastic elastomer material (for example, ethylene-vinyl acetate copolymer, thermoplastic elastomer TPE, or thermoplastic polyurethane elastomer TPU) or a combination of at least two of them.
  • AR acrylic system
  • PU polyurethane system
  • SR silicone resin system
  • EP epoxy resin system
  • MF melamine resin system
  • PF phenolic resin system
  • UF urea-formaldehyde resin system
  • thermoplastic elastomer material for example, ethylene-vinyl acetate copolymer, thermoplastic elastomer TPE, or thermoplastic polyurethane elastomer TPU
  • the polymer curing system may be selected from one or a combination of at least two of acrylic resin systems, polyurethane systems, silicone systems, epoxy resin systems, or thermoplastic elastic materials.
  • the inorganic coating of the light-shielding medium is selected from one or a combination of at least two of carbon element, carbide, carbonitride, and sulfide.
  • the thickness t of the collimating hole layer of the collimating film is selected from 0.5 to 7 ⁇ m, preferably 1 to 5 ⁇ m, and more preferably 2 to 3 ⁇ m.
  • the collimating hole diameter ⁇ of the collimating hole layer of the collimating film is selected from 1 to 10 ⁇ m, more preferably 3 to 5 ⁇ m.
  • the thickness T of the flexible base layer may be 10 ⁇ m-50 ⁇ m, for example, 10 ⁇ m, 15 ⁇ m, 20 ⁇ m, 25 ⁇ m, 38 ⁇ m or 50 ⁇ m.
  • the main optical axis pitch P between adjacent microlenses of the collimating lens layer may be 10 ⁇ m-15 ⁇ m, for example, 10 ⁇ m, 15 ⁇ m, 18 ⁇ m, 20 ⁇ m, 25 ⁇ m, 30 ⁇ m or 50 ⁇ m.
  • the microlens curvature radius R of the collimating lens layer may be 6.1 ⁇ m-30.2 ⁇ m, for example, 6.1 ⁇ m, 6.9 ⁇ m, 7.9 ⁇ m, 9.4 ⁇ m, 11.2 ⁇ m, 11.3 ⁇ m, 12 ⁇ m, 12.1 ⁇ m, 12.6 ⁇ m, 12.8 ⁇ m, 13.3 ⁇ m, 13.6 ⁇ m, 14 ⁇ m, 14.3 ⁇ m, 14.3 ⁇ m, 14.8 ⁇ m, 15 ⁇ m, 15.1 ⁇ m, 15.7 ⁇ m, 15.9 ⁇ m, 16 ⁇ m, 16.1 ⁇ m, 16.7 ⁇ m, 17 ⁇ m, 17.2 ⁇ m, 17.3 ⁇ m, 18 ⁇ m, 18.1 ⁇ m, 18.3 ⁇ m, 18.8 ⁇ m, 19.3 ⁇ m, 19.4 ⁇ m, 19.6 ⁇ m, 19.8 ⁇ m, 20 ⁇ m, 20.6 ⁇ m, 20.8 ⁇ m, 21.6 ⁇ m, 22.5 ⁇ m, 25.6 ⁇ m, or 30.2 ⁇ m.
  • the thickness H of the collimating lens layer may be 1.1 ⁇ m-27.4 ⁇ m, such as 1.1 ⁇ m, 2.4 ⁇ m, 2.5 ⁇ m, 3.0 ⁇ m, 3.1 ⁇ m, 3.2 ⁇ m, 3.5 ⁇ m, 3.8 ⁇ m, 4.1 ⁇ m, 5.0 ⁇ m, 5.8 ⁇ m, 6.0 ⁇ m, 6.2 ⁇ m, 6.8 ⁇ m, 7.2 ⁇ m, 7.8 ⁇ m, 8.5 ⁇ m, 8.6 ⁇ m, 8.7 ⁇ m, 9.2 ⁇ m, 10.4 ⁇ m, 10.7 ⁇ m, 10.8 ⁇ m, 11 ⁇ m, 11.1 ⁇ m, 11.4 ⁇ m, 11.5 ⁇ m, 12.9 ⁇ m, 13.6 ⁇ m, 14.1 ⁇ m, 14.6 ⁇ m, 15.0 ⁇ m, 15.4 ⁇ m, 16.3 ⁇ m, 17.3 ⁇ m, 18.1 ⁇ m, 19.8 ⁇ m, 20.5 ⁇ m, 21.3 ⁇ m, 22.2 ⁇ m, 22.7 ⁇ m, 25 ⁇ m, or 27.4 ⁇ m.
  • the spot diameter D formed by the microlens on the lower surface of the flexible substrate layer may be 0.1 ⁇ m-7.8 ⁇ m, for example, 0.1 ⁇ m, 0.3 ⁇ m, 0.4 ⁇ m, 0.5 ⁇ m, 0.6 ⁇ m, 0.7 ⁇ m, 0.8 ⁇ m, 1.0 ⁇ m.
  • the thickness t of the collimating hole layer may be 0.5-7 ⁇ m, for example, 0.5 ⁇ m, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, or 7 ⁇ m.
  • the collimating hole diameter ⁇ may be 1-10 ⁇ m, for example, 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 8 ⁇ m, or 10 ⁇ m.
  • the refractive index n1 of the collimating lens layer may be 1.34-1.7, for example, 1.34, 1.4, 1.47, 1.48, 1.5, 1.59, 1.6, 1.65, 1.66, or 1.7.
  • the refractive index n2 of the flexible substrate layer may be 1.48-1.7, such as 1.48, 1.49, 1.5, 1.6, 1.65, 1.66 or 1.7.
  • the collimating film provided by the present invention includes a collimating lens layer (41), a flexible substrate layer (42) (referred to as a substrate for short), and a collimating hole layer (43).
  • the collimating lens layer is placed on the upper surface of the substrate.
  • the collimating hole layer is placed on the lower surface of the substrate, the collimating lens layer (41) includes a microlens array (41A) and the thickness (41B), and the collimating hole layer (43) includes a light-shielding medium (43A) And a collimating hole array formed by hollowing out the medium (consisting of a certain number of collimating holes (43B)).
  • the collimating lens array and the collimating hole array in the collimating film are all arranged in equilateral triangles
  • the material of the collimating lens layer (41) is PMMA
  • the flexible substrate layer (42 The material of) is PET
  • the light-shielding medium (43A) of the collimating hole layer (43) is an inorganic coating titanium carbide
  • the collimating film uses a microlens perforating method to punch the collimating hole (43B).
  • P is 10-30 ⁇ m, R is 9.4 ⁇ m-20.6 ⁇ m, H is 3 ⁇ m-27.4 ⁇ m, and n1 is 1.5;
  • T 25 ⁇ m
  • n2 1.65
  • D 0.3 ⁇ 4.0 ⁇ m
  • t 2.0 ⁇ m
  • ⁇ 4.0 ⁇ m
  • the deviation ⁇ 0.18-0.90 ⁇ m.
  • the collimating lens array and the collimating hole array in the collimating film are all arranged in equilateral triangles
  • the material of the collimating lens layer (41) is PMMA
  • the flexible substrate layer (42) The material of is PET
  • the light-shielding medium (43A) of the collimating hole layer (43) is an inorganic coating titanium carbide
  • the collimating film uses a microlens perforation method to punch the collimating hole (43B)
  • the other parameters are as follows :
  • P is 10-25 ⁇ m, R is 6.1 ⁇ m-19.8 ⁇ m, H is 2.5 ⁇ m-10.7 ⁇ m, and n1 is 1.5;
  • T 10-50 ⁇ m, n2 is 1.65, D is 0.6 ⁇ 3.9 ⁇ m;
  • t 1.0-3.0 ⁇ m
  • ⁇ 2.0-5.0 ⁇ m
  • the deviation ⁇ is 0.26-0.49 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all arranged closely in a regular triangle
  • the material of the collimating lens layer (41) is PMMA
  • the flexible substrate layer (42) The material of is PET
  • the light-shielding medium (43A) of the collimating hole layer (43) is an inorganic coating titanium carbide
  • the collimating film uses a microlens perforation method to punch the collimating hole (43B)
  • P is 10-50 ⁇ m, R is 16 ⁇ m-30.2 ⁇ m, H is 1.1 ⁇ m-21.3 ⁇ m, and n1 is 1.5;
  • T is 50 ⁇ m, n2 is 1.65, D is 0.1 ⁇ 7.8 ⁇ m;
  • t is 0.5 ⁇ m
  • ⁇ is 1.0-8.0 ⁇ m.
  • the deviation ⁇ is 0.21-0.88 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are arranged in equilateral triangles
  • the material of the collimating lens layer (41) is PMMA
  • the flexible substrate layer ( 42) is made of PET
  • the light-shielding medium (43A) of the collimating hole layer (43) is an inorganic coating titanium carbide.
  • the collimating film uses microlens perforation to make the collimating hole (43B). Other parameters are as follows :
  • P is 30 ⁇ m, R is 19.3 ⁇ m, H is 10.8 ⁇ m, and n1 is 1.5;
  • T 38 ⁇ m
  • n2 1.65
  • D 3.6 ⁇ m
  • t 0.5-7 ⁇ m
  • ⁇ 5.0-10.0 ⁇ m
  • the deviation ⁇ is 0.46-0.99 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all arranged closely in a regular triangle, the material of the collimating lens layer (41) is PMMA, and further, it is cured by light Acrylic resin is polymerized, and the refractive index n1 is adjustable from 1.4 to 1.6.
  • the light-shielding medium (43A) of the collimating hole layer (43) is an inorganic coating titanium carbide, and the collimating film uses a microlens perforating method to punch the collimating hole (43B), and other parameters are as follows:
  • P is 20-25 ⁇ m, R is 15.9-22.5 ⁇ m, H is 3.2-9.2 ⁇ m, n1 is 1.4-1.6;
  • T 38-50 ⁇ m
  • n2 1.5-1.65
  • D is 0.5-3.6 ⁇ m
  • t 2.0 ⁇ m
  • ⁇ 4.0 ⁇ m
  • the deviation ⁇ is 0.25-0.66 ⁇ m.
  • Example 58 the collimating lens array and the collimating hole array of the collimating film are both square and closely arranged (as shown in FIG. 7), and the material of the collimating lens layer (41) is PMMA, a flexible substrate
  • the material of the layer (42) is PET
  • the light-shielding medium (43A) of the collimating hole layer (43) is an inorganic coating titanium carbide
  • the collimating film uses a microlens perforation method to punch the collimating hole (43B), and other items
  • the parameters are as follows:
  • P is 25 ⁇ m, R is 19.6 ⁇ m, H is 11.1 ⁇ m, and n1 is 1.5;
  • T 38 ⁇ m
  • n2 1.65
  • D 3.9 ⁇ m
  • t 2.0 ⁇ m
  • ⁇ 4.0 ⁇ m
  • the deviation ⁇ 0.69 ⁇ m.
  • the present invention also provides a method for preparing the collimating film, and the collimating hole is punched by a micro-focusing method.
  • the laser is vertically irradiated to the collimating lens layer, the laser is focused through the microlenses of the collimating lens layer, and the focused light spot falls on the collimating hole layer to make a collimating hole.
  • the distribution of the collimating hole array and the microlens array are completely consistent, and the center of any collimating hole is on the main optical axis of the corresponding microlens.
  • preparation method includes the following steps:
  • the collimating lens layer is formed on the upper surface of the flexible substrate layer (light curing, thermal curing, hot pressing, etc. can be used) to form a lens array (convex);
  • a large-area flat-top laser (parallel laser after Gaussian beam shaping) is used to irradiate the microlens array vertically with appropriate low energy, and after each microlens, it is focused on the light-shielding medium (ie micro-focusing method) and shot Corresponding to the collimating holes, an array of collimating holes with the same distribution is generated to form a collimating hole layer.
  • micro-focusing method includes the following features:
  • the flat-top laser after beam shaping is used as the laser source. After shaping, the irradiated area becomes larger and the energy density decreases;
  • the micro-focusing spot should be small enough within a reasonable range, and the focal position should be designed on the lower surface of the PET or deeper, so that the energy is concentrated on the light-shielding layer (light-shielding medium);
  • the process of the micro-focusing method (as shown in Figure 4) is divided into four basic steps: (a) Flat-top laser (5) with appropriate energy (too high hole is too large, even burned to the substrate, over Low, no perforation), hit the collimating lens layer (41) of the semi-finished collimating film, the micro lens (41A) realizes micro-focusing, the flesh thickness (41B) realizes the pre-shrinking of the spot area, and finally the laser passes through the substrate layer ( 42), the light-shielding medium (43A) is focused into a very small spot to achieve a high concentration of energy; (b) due to the absorption of light by the light-shielding medium, the instantaneous accumulation of energy causes the light-shielding medium at the spot position to be burned through instantly and produce Some ash content, in fact, the first two steps only need microsecond level, which is very fast; (c) After the ash content is removed, the collimating holes (43B) are exposed.
  • collimating holes are on the main optical axis of the microlens (40B). ), so it is highly aligned with the micro lens (41A), avoiding the time-consuming alignment process.
  • the collimating film (4) of the present invention is already a finished product, including a complete structure—the collimating lens layer (41), The base layer (42), the collimation hole layer (43); (d) the collimation film (4) has met the normal or close to normal collimation light transmission at this time, and can be tested with ordinary strength during on-line production
  • the light source such as white light, green light, three-wave lamp
  • the light source is irradiated from the surface of the microlens, and the light will pass through the collimating hole, so that the image of the light-transmitting hole array can be observed on the back side, and the transmitted light intensity can be quantified for inspection
  • the quality of punching can be easily detected automatically on the assembly line in this process, and the images captured by sampling at specific locations can also be analyzed digital
  • the traditional drilling method has greater limitations (as shown in Figure 5): (a) Gaussian laser (7), which is focused by the lens group of the laser head, The back side of the semi-finished product is hit on the light-shielding medium (43A); (b) the light-shielding layer is sequentially burned through at different positions, and some ash is generated; (c) when the ash is removed, the collimating hole is exposed.
  • Gaussian laser (7) which is focused by the lens group of the laser head, The back side of the semi-finished product is hit on the light-shielding medium (43A);
  • the light-shielding layer is sequentially burned through at different positions, and some ash is generated; (c) when the ash is removed, the collimating hole is exposed.
  • the entire alignment process needs to locate the origin O (or Mark point), the front CCD (Charge Coupled Device) high-definition camera is aligned with the optical center of the lens, and the laser head on the back will be linked with the front CCD lens to find To the corresponding collimation hole position, the initial displacement (vector or coordinate difference) between the first point and the position is calculated.
  • This initial positioning process is very time-consuming and complicated, and requires high equipment; then, based on the initial The displacement amount and the displacement amount between the points can be calculated to locate all the point positions, and 2 ⁇ n points can be printed in sequence.
  • the galvanometer group can be used to shorten the time in this process, n cannot be set too large, otherwise the cumulative error will inevitably exceed 1 ⁇ m , Will be even larger, especially the galvanometer will cause the angle to tilt, the spot becomes larger and deformed, and the error accumulates faster and faster; finally, when the error accumulates to be unacceptable, you need to return to the origin O and search for the first point again. That is, the initial positioning process is repeated.
  • the galvanometer group is used to shorten the time, since n cannot be too large, the initial positioning process needs to be performed frequently, which makes this method extremely time-consuming, complicated and dependent on equipment.
  • the punching process is not only costly but also low precision. .
  • the limitations of the traditional perforating method are more than this: the above-mentioned process of locating the first point and calculating the points from 2 to n requires a prerequisite, that is, the spacing of the microlenses is completely accurate; in fact, on the one hand , The micro lens mold is also prepared by laser drilling, there will be errors, so the alignment error of the traditional method will be further increased, especially when the mold accuracy is not so high; on the other hand, some special molds are prepared In the irregular microlens layer, the arrangement precision and shape precision of the microlenses are poor, or the designed pitch is uneven or even disordered.
  • the mold precision and preparation cost of the microlens layer are increased in disguise, resulting in a very high cost of the entire collimating film, not to mention the realization of the alignment and perforation of the irregular microlens layer (and the microfocusing method of the present invention) Can be easily achieved).
  • the molding method of the microlens array should be selected according to the type of transparent polymer and the application, and the present invention is not preferred; the coating method of the shading medium should be selected according to the type of the shading medium, and the wet coating method should be selected for the organic coating , Inorganic coating needs to choose dry coating (that is, physical vapor deposition) method.
  • the method for preparing the collimating film provided by the present invention is suitable for the production of sheets and also for the production of coils.
  • the collimating film can be used as a flexible collimating device for image sensor modules.
  • the collimating film can collimate and filter the diffuse light at a single point of the image to a certain extent, form a normal beamlet light signal, and transmit it to the corresponding photoelectric sensor. It is especially suitable for large-size, ultra-thin, Even in the flexible image recognition module.
  • the collimating film provided by the present invention uses a polymer film with a thickness of 10-50 ⁇ m as the flexible base layer, which realizes the flexibility, ultra-thinness and large-size of the collimating device, and is particularly suitable for large-scale applications. In image recognition modules of size, ultra-thin, and even flexibility.
  • the collimating film provided by the present invention adopts the micro-focus method to perforate.
  • the distribution of the collimating hole array and the microlens array are exactly the same, and the center of each collimating hole is at the center of the corresponding microlens.
  • one-to-one high-precision alignment, alignment deviation ⁇ 1 ⁇ m not only greatly improves the transmission of signal light, but also allows the collimation structure to be further reduced (such as the simultaneous reduction of microlenses and collimation holes) to reduce crosstalk and improve
  • the signal-to-noise ratio of the collimating film is improved, and the production efficiency is greatly improved, and the cost is reduced.
  • the collimating film provided by the present invention only includes one collimating hole layer, which fundamentally solves the problem of difficulty in alignment between the two collimating diaphragms, and has low thickness, good toughness, Not fragile, the center of the collimating hole prepared by the micro-focusing method is on the main optical axis of the corresponding micro lens, and the collimating hole and the corresponding micro lens are aligned accurately.
  • the preparation method of the collimating film provided by the present invention is easy to operate, can be mass-produced, and improves the production yield.
  • the collimating film provided by the present invention has excellent performance and can pass collimated light and filter diffused light.
  • the collimating film provided by the present invention can be applied to large-size, ultra-thin image recognition modules, so that the mass production of large-size, ultra-thin, and even flexible image recognition modules is greatly improved.
  • the collimating film of the present invention has obvious advantages.
  • the orderly distributed collimating structure (referring to the orderly arrangement of the microlens array of the collimating lens layer) can meet the basic image recognition requirements in practical applications, but there are interference fringes caused by excessive regularity, such as Shown in Figure 11a. Therefore, it is necessary to optimize the collimation structure to a disorderly distribution, destroy regularity, and weaken interference fringes, as shown in Figure 11b, to further improve the accuracy of image recognition (recognition rate).
  • the microlens array of the collimating lens layer of the interference-reducing collimating film provided by the present invention is arranged in a disorderly manner. Due to the micro-focus perforation method, the collimating hole array of the collimating hole layer is completely consistent with the micro lens array. It not only maintains the characteristics of disorderly distribution, but also maintains high-precision coaxial alignment, which is always impossible to achieve with traditional punching methods.
  • the collimating film of the disordered microlens array can destroy the regularity of the ordered microlens array and reduce the interference fringes caused by the regularity (as shown in FIG. 11b), so as to further improve the image recognition of the collimating film provided by the present invention. Accuracy (recognition rate).
  • the collimating lens array and the collimating hole array of the disordered array collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, any three The main optical axis coordinates of the overlapping microlenses are connected to form a normal triangle (not a regular triangle)).
  • the value of P ranges from 5 to 55 ⁇ m, and the main optical axis distance P of the two overlapping microlenses varies randomly within a certain value range
  • the change in the distance P between adjacent main optical axes is A (the difference between the highest value and the lowest value in the value range of P)
  • the median value of the distance between adjacent main optical axes P is Pm (the highest value in the value range of P And the average of the lowest value)
  • Pm-0.5A ⁇ P ⁇ Pm+0.5A the median value Pm is selected from 10-50 ⁇ m, preferably 15-30 ⁇ m, more preferably 18-25 ⁇ m
  • the amount A is selected from 1 to 10 ⁇ m, preferably 2 to 6 ⁇ m.
  • the radius R of the microlens is 6.1 ⁇ m-30.2 ⁇ m
  • the height H of the collimating lens layer is 1.1 ⁇ m-27.4 ⁇ m
  • the collimating lens layer is made of
  • the refractive index n1 is 1.34 to 1.7
  • the thickness T of the flexible substrate layer is 10 to 50 ⁇ m
  • the refractive index n2 of the material of the flexible substrate layer is 1.48 to 1.7
  • the thickness t of the straight hole layer is 0.5-7 ⁇ m
  • the diameter ⁇ of the collimating hole in the collimating hole array is 1-10 ⁇ m.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the micro lenses are closely arranged and overlap each other (as shown in FIG. 12, any three overlap each other).
  • the main optical axis coordinates of the microlenses are connected to form a common triangle (not a regular triangle).
  • the main optical axis spacing P of the two overlapping microlenses changes disorderly within a certain value range (Pm ⁇ 0.5A).
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible base layer 42 is PET
  • the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide
  • the collimating film uses microlens perforation to produce collimation.
  • Hole 43B other parameters are as follows:
  • P is Pm ⁇ 0.5A, Pm is 30 ⁇ m, A is 1-10 ⁇ m, R is 20.6 ⁇ m, H is 27.4 ⁇ m, and n1 is 1.5;
  • T 25 ⁇ m
  • n2 1.65
  • D 3.1 ⁇ m
  • t 2.0 ⁇ m
  • ⁇ 4.0 ⁇ m
  • the deviation ⁇ 0.81 ⁇ m.
  • the interference-reducing collimating film provided by the present invention only includes one layer of collimating holes, which fundamentally solves the problem of difficulty in alignment between the two layers of collimating diaphragms, and has low thickness and toughness.
  • Good, not fragile the center of the collimating hole prepared by the micro-focusing method is on the main optical axis of the corresponding micro lens, and the alignment of the collimating hole and the corresponding micro lens is accurate.
  • the preparation method of the interference-reducing collimating film provided by the present invention is easy to operate, can be mass-produced, and improves the production yield.
  • the interference-reducing collimating film provided by the present invention has excellent performance, can pass collimated light, filter diffused light, and reduce light interference.
  • the interference-reducing collimating film provided by the present invention can be applied to large-size, ultra-thin image recognition modules, which greatly improves the mass production of large-size, ultra-thin, and even flexible image recognition modules.
  • the interference-reducing collimating film of the present invention has obvious advantages.
  • the present invention provides a laminated collimating film, which includes a laminated adhesive layer and the interference reducing collimation film of the present invention; the laminated adhesive layer and the interference reducing collimation film The collimating hole layers in the collimating film are glued together.
  • the bonding adhesive layer is selected from one of solid optical transparent adhesives, high-transmittance pressure-sensitive adhesives or transparent hot melt adhesives.
  • the thickness of the adhesive layer is 5 to 35 ⁇ m.
  • the present invention also provides an image recognition module.
  • the image recognition module sequentially includes a collimation layer, a filter layer and a photoelectric sensing layer; the collimation layer is selected from the laminated type described in the present invention.
  • the collimating film or the interference reducing collimating film of the present invention is selected from the laminated type described in the present invention.
  • Figure 14 is a schematic diagram of the trend of large-screen image recognition modules (take the OLED mobile phone fingerprint recognition module as an example), showing the top view of four designs of OLED mobile phones (01), and there is a fingerprint recognition module under the OLED screen (02) (03). Fingers (04) need to be placed in these specific areas to be able to identify and unlock: Among them, (a) is the traditional local recognition design.
  • the fingerprint recognition module is very small, it is often displayed in this area when the screen is activated An icon to indicate the precise position of the finger; (b) The fingerprint recognition module covers an area of about 1/4 screen, and it is no problem to expand from single-finger recognition and unlocking to two-finger recognition and unlocking; (c), ( The design of d) intends to realize half-screen or even full-screen, which puts forward higher requirements for the large-screen fingerprint recognition module.
  • FIG 15 is a schematic diagram of the image recognition module structure (taking the OLED mobile phone fingerprint recognition module as an example).
  • the interference-reducing collimating film layer (05) is located in the middle layer, above the collimating film It is an OLED screen (02), with a filter layer (06) and a photoelectric sensing layer (07) underneath.
  • the collimating film is a soft base component, its dimensional stability (heat shrinkage, thermal expansion, wrinkles, etc.) is its weak point. Therefore, it needs to be bound with the underlying component to increase the overall stiffness and thickness when used in a large area.
  • the component can be a hard-based component (such as a filter layer), or a soft-based component (such as a filter layer can also be prepared with a soft substrate, and the photoelectric sensor chip can also be prepared with a TFT (thin film transistor).
  • the laminated collimating film provided by the present invention has a bonding adhesive layer (44), which can bond the collimating film of the soft base (that is, the flexible base layer) with the lower part of the image recognition module, thereby improving the collimating film
  • the dimensional stability is shown in Figure 16. Obviously, the flatness of the collimating film after lamination is higher, which can reduce the optical distortion caused by the film material wave (Waving), and enhance the accuracy of its image recognition.
  • the laminated collimating film has four main structures from top to bottom, which are a disordered array collimating lens layer (41), a flexible substrate layer (42), a collimating hole layer (43), and an adhesive layer (44), as shown in Figure 17.
  • the design parameters of the disordered array collimating lens layer (41), the flexible substrate layer (42), and the collimating hole layer (43) are exactly the same as those of the interference-reducing collimating film, and the adhesive layer (44)
  • the thickness of is T 2 , selected from 5-50 ⁇ m, preferably 10-25 ⁇ m. Too thin glue layer will lead to incomplete bonding (regardless of reliability before and after), and too thick will cause signal light loss or crosstalk.
  • the bonding adhesive layer may be selected from solid OCA (optical transparent adhesive), high-transmittance PSA (pressure sensitive adhesive), or transparent hot melt adhesive, etc., preferably OCA and PSA with high light transmittance and reworkability.
  • the materials of the OCA and PSA are respectively selected from a thermosetting polyacrylate system or a light curing polyacrylate system.
  • the collimating lens array and the collimating hole array are both disordered arrays, and the microlenses are closely arranged to overlap each other (as shown in FIG. 12, any three of them intersect each other).
  • the main optical axis coordinates of the stacked microlenses are connected to form a common triangle (not a regular triangle).
  • the value of P ranges from 5 to 55 ⁇ m.
  • the main optical axis spacing P of the two microlenses changes randomly within a certain value range, and the change of the adjacent main optical axis spacing P is A (the difference between the highest value and the lowest value in the value range of P), adjacent
  • the median value of the main optical axis pitch P is Pm (the average value of the highest value and the lowest value in the value range of P), then Pm-0.5A ⁇ P ⁇ Pm+0.5A; the median value Pm is selected from 10-50 ⁇ m, preferably It is 15 to 30 ⁇ m, more preferably 18 to 25 ⁇ m, and the amount of change A of the main optical axis pitch P is selected from 1 to 10 ⁇ m, preferably 2 to 6 ⁇ m.
  • the radius R of the microlens is 6.1 ⁇ m-30.2 ⁇ m
  • the height H of the collimating lens layer is 1.1 ⁇ m-27.4 ⁇ m
  • the refractive index n1 of the material of the collimating lens layer is 1.34-1.7
  • the thickness T of the flexible base layer is 10-50 ⁇ m
  • the refractive index n2 of the flexible base layer material is 1.48-1.7
  • the thickness t of the collimating hole layer is 0.5-7 ⁇ m
  • the collimating hole array The diameter of the collimating hole ⁇ is 1 to 10 ⁇ m.
  • the present invention also provides a method for preparing the laminated collimating film, and the collimating hole is punched by a micro-focusing method.
  • the laser is vertically irradiated to the collimating lens layer, the laser is focused through the microlenses of the collimating lens layer, and the focused light spot falls on the collimating hole layer to make a collimating hole.
  • the distribution of the collimating hole array and the microlens array are completely consistent, and the center of any collimating hole is on the main optical axis of the corresponding microlens.
  • the present invention also provides a method for preparing the laminated collimating film, which includes the following steps:
  • preparation method includes the following steps:
  • the OCA/PSA adhesive layer is used for the bonding of the underlying components.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, any three overlap each other).
  • the main optical axis coordinates of the microlenses are connected to form a common triangle.
  • the main optical axis spacing P of the two overlapping microlenses varies randomly within a certain value range (Pm ⁇ 0.5A), where the median value Pm Is 18 ⁇ m or 15 ⁇ m, and the amount of change A is 4 ⁇ m, that is, the value range of P is 18 ⁇ 2 ⁇ m or 15 ⁇ 2 ⁇ m, and other parameters are listed in Table 10.
  • the collimating lens layer 41 is made of PMMA, and the flexible base layer 42
  • the material of the collimating hole layer 43 is PET, and the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide.
  • the collimating film uses a microlens perforating method to make the collimating hole 43B. The other parameters are listed in Table 10.
  • the adhesive layer 44 of Examples 93 to 99 is solid OCA, and the material is a heat-curing polyacrylate system; the adhesive layer 44 of Example 100 is a high-permeability PSA, and the material is a heat-curing polyacrylate system; The laminating adhesive layer 44 is solid OCA and the material is a light-curing polyacrylate system; the laminating adhesive layer 44 of Example 102 is a high-transmittance PSA and the material is a light-curing polyacrylate system.
  • Other parameters are as follows:
  • P is Pm ⁇ 0.5A
  • Pm is 18 ⁇ m
  • A is 4 ⁇ m
  • R is 14.8 ⁇ m
  • H is 16.3 ⁇ m
  • n1 is 1.5;
  • T 25 ⁇ m
  • n2 1.65
  • D is 1.1 ⁇ m
  • t 2 ⁇ m
  • ⁇ 4 ⁇ m
  • the deviation ⁇ 0.41 ⁇ m.
  • P is Pm ⁇ 0.5A
  • Pm is 15 ⁇ m
  • A is 4 ⁇ m
  • R is 17 ⁇ m
  • H is 2.4 ⁇ m
  • n1 is 1.5;
  • T 50 ⁇ m
  • n2 is 1.65
  • D is 0.5 ⁇ m
  • t is 0.5 ⁇ m
  • ⁇ is 5.0 ⁇ m
  • the deviation ⁇ is 0.25 ⁇ m.
  • the laminated collimating film provided by the present invention only includes one layer of collimating holes, which fundamentally solves the problem of difficulty in alignment between the two layers of collimating diaphragms, and has a low thickness.
  • Good toughness, not fragile the center of the collimating hole prepared by the micro-focusing method is on the main optical axis of the corresponding micro lens, and the collimating hole is accurately aligned with the corresponding micro lens.
  • the preparation method of the laminated collimating film provided by the present invention is easy to operate, can be mass-produced, and improves the production yield.
  • the laminated collimating film provided by the present invention has excellent performance, can pass collimated light, filter diffused light, and reduce light interference.
  • the laminated collimating film provided by the present invention has a bonding adhesive layer, which can be bonded to the lower layer components, thereby improving the dimensional stability of the flexible collimating film and reducing optical distortion.
  • the laminated collimating film provided by the present invention can be applied to large-size, ultra-thin image recognition modules, so that the mass production of large-size, ultra-thin, and even flexible image recognition modules is greatly improved.
  • the laminated collimating film of the present invention has obvious advantages.
  • the image recognition module provided by the present invention has high recognition accuracy and can be applied to fingerprint unlocking of consumer electronic products such as mobile phones (OLED screens).
  • the light-shielding medium of the collimating hole layer has a light-shielding function and can block light, that is, the light transmittance of a specific wavelength band is less than a certain value.
  • the transmittance of the light-shielding medium should be at least ⁇ 1%, that is, the cut-off depth (cut-off level) OD2.
  • the light-shielding medium of the present invention adopts an opaque organic coating and an inorganic coating, and the key substances contained therein are all light-absorbing substances, and the light-absorbing substances are selected from carbonaceous, carbide, carbonitride, sulfide and the like.
  • the light-shielding medium of the present invention can also adopt a metal plating layer.
  • the metal plating layer can also achieve a light-shielding function, and the transmittance is less than 1%.
  • the metal coating can be made very dense. Under the same thickness, both the cut-off depth (the deeper, the lower the transmittance, the less the noise) and the cut-off range (the wavelength range that is cut off) have advantages (as shown in Figure 20a) . Therefore, a three-layer light-shielding design of black light-absorbing material layer+metal plating layer+black light-absorbing material layer can be adopted to achieve a better light-shielding effect.
  • the light-sensing wavelength bands of different photoelectric sensors are different, and the light of the corresponding wavelength band must be blocked by the light-shielding layer, otherwise it will be received by the photoelectric sensor and generate noise.
  • the photosensitive wave band of CMOS is 400-1100nm
  • the photosensitive wave band of TFT is 400-850nm. Therefore, the metal coating in the three-layer shading design has deep cut-off characteristics for the near-infrared region, so it has certain advantages in the CMOS image recognition module used for photoelectric sensors.
  • the light-shielding medium forms the light-shielding layer), then the thickness needs to be increased to compensate.
  • the metal coating in the three-layer shading design also has the following advantages: 1.
  • the melting point of metals is generally lower than that of metal carbides (most metals have a melting point less than 2000°C, but carbides are often higher than 3000°C, such as the melting point of titanium/zirconium. It is 1675°C/1852°C, but the melting points of titanium carbide/zirconium carbide are 3160°C/3540°C respectively).
  • the metal will form a circular boundary of the molten recast zone (also called the recast layer) (
  • the crater shown as 43B2 in Figure 22
  • the crater has better control over the shape of the hole, with a higher roundness (of course, the recast area is not necessarily round, but this does not affect the light transmission), and it is not easy to produce special-shaped holes; 2.
  • the metal is ductile, and the thin metal coating has a certain degree of flexibility. It is not easy to cause cracks and powdering during the drilling process (metal carbide is more brittle, it is easier to crack and powder), and the reliability is higher. As shown in Figure 21 for comparison.
  • Figure 20b shows a disadvantage of the metal coating, that is, the reflectivity is compared with black. The light-absorbing material is much higher, and the high reflectivity of the front will cause the laser drilling to require more energy (a lot of energy is reflected), or you need to choose a suitable laser, and use the metal layer to absorb the strong wave band for drilling.
  • the black light-absorbing material 43A1 is installed on the upper and lower layers of the metal plating layer 43A2, the laser energy will be largely absorbed by the upper layer 43A1 (Figure 24 reflectivity ⁇ 4%, transmittance ⁇ 1%, absorption rate> 95% ), and the converted heat will also be quickly transferred to the metal coating through the upper layer to heat, melt, and evaporate, thereby creating a collimating hole.
  • the melting and evaporation of the metal is a faster heat dissipation process, and it is not easy to accumulate black light-absorbing substances
  • the heat generates cracks and chalking problems; and the lower layer 43A1 helps to absorb the multiple reflection crosstalk light 0822 below the small holes, as shown in FIG. 26.
  • the three-layer shading design not only helps to improve the roundness of the collimating hole, the overall shading layer is not easy to be broken and has higher reliability, but also helps to improve the utilization of laser energy, further reduce noise and improve signal-to-noise ratio .
  • the production process of the three-layer shading design requires two more steps in the production process of the back side, that is, the upper (inner) black light-absorbing material layer is produced first, and then the middle metal plating layer is produced.
  • the black light-absorbing material is preferably an inorganic plating layer, while an organic coating is not preferable.
  • both the black light-absorbing material and metal can be dry-coated (For example, physical vapor deposition), for equipment with multiple chambers and multiple targets, the three-layer process can even be completed through continuous operations. If the upper layer and the lower layer have the same black light-absorbing material, reciprocating winding coating equipment can also be used. At least two chambers can complete the three-layer process.
  • the collimating film sequentially includes a collimating lens layer, a flexible substrate layer and a collimating hole layer;
  • the collimating lens layer includes a microlens array and a thickness;
  • the collimating hole layer includes a light-shielding medium and a collimating hole array formed after the light-shielding medium is hollowed out.
  • the collimating hole layer includes a light-shielding medium layer (light-shielding layer for short) and a collimating hole array.
  • the light-shielding medium sequentially includes an upper black light-absorbing material layer, a metal plating layer, and a lower black light-absorbing material layer.
  • the light-shielding medium sequentially includes an upper black light-absorbing material layer, a metal plating layer, and a lower black light-absorbing material layer.
  • the upper black light-absorbing material layer is placed between the flexible substrate layer and the metal plating layer, and the metal plating layer is placed on the upper black layer. Between the light-absorbing material layer and the lower black light-absorbing material layer.
  • the light-shielding medium has a three-layer structure, the upper layer is a black light-absorbing material layer, the middle layer is a metal plating layer, and the lower layer is a black light-absorbing material layer.
  • the thickness of the middle metal plating layer accounts for 10% to 90% of the total thickness of the three-layer structure of the light-shielding medium, preferably 30% to 70%.
  • the ratio of the thickness of the upper black light-absorbing material layer and the lower black light-absorbing material layer is 0.1:1-10:1, preferably 0.5:1-2:1.
  • the black light-absorbing material is selected from one of carbon element, carbide, carbonitride, and sulfide.
  • the metal plating layer is selected from indium, tin, zinc, antimony, magnesium, aluminum, strontium, cerium, germanium, lanthanum, silver, gold, copper, manganese, gadolinium, nickel, cobalt, which are suitable for magnetron sputtering.
  • yttrium, iron, titanium, platinum, zirconium, chromium, hafnium, niobium, or molybdenum is suitable for magnetron sputtering.
  • the black light-absorbing materials of the upper black light-absorbing material layer and the lower black light-absorbing material layer may be the same or different. For the convenience of the manufacturing process, they are preferably the same.
  • the metal plating layer is preferably one of tin, zinc, aluminum, germanium, silver, copper, manganese, nickel, cobalt, iron, titanium, chromium, niobium, or molybdenum. These metal coating raw materials are more common and low in cost.
  • the coating method of the shading medium should be selected according to the type of shading medium.
  • the black light-absorbing material can be either wet coating or dry coating. Dry coating is preferred. Dry coating is required for metal coating. (Such as physical vapor deposition) method.
  • the light-shielding medium has a three-layer design, the upper layer is a black light-absorbing material layer, the middle layer is a metal plating layer, and the lower layer is a black light-absorbing material layer.
  • the light-shielding medium has a three-layer design, the upper layer is a black light-absorbing material layer, the middle layer is a metal plating layer, and the lower layer is a black light-absorbing material layer.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, any three overlap each other).
  • the main optical axis coordinates of the microlenses are connected to form a common triangle.
  • the main optical axis spacing P of the two overlapping microlenses varies randomly within a certain value range (Pm ⁇ 0.5A), where the median value Pm
  • the value of P is 18 ⁇ m, and the amount of change A is 4 ⁇ m, that is, the value range of P is 18 ⁇ 2 ⁇ m, and other parameters are listed in Table 11.
  • the material of the collimating lens layer 41 is PMMA, and the material of the flexible substrate layer 42 is PET.
  • the shading medium 43A of the straight hole layer 43 is a three-layer shading design, the upper and lower layers are both black light-absorbing material 43A1, and the middle layer is a metal plating layer 43A2.
  • the collimating film uses microlens perforation to make the collimating holes 43B.
  • Example 103 The adhesive layer 44 of ⁇ 112 is solid OCA, and the material is a thermosetting polyacrylate system; the black light-absorbing materials of Examples 103 ⁇ 112 are carbon element, chromium carbide, titanium carbide, boron carbide, titanium carbonitride, carbon Boron nitride, ferrous sulfide, molybdenum disulfide, cobalt disulfide, nickel sulfide, and the metal coatings are aluminum, germanium, silver, copper, manganese, nickel, cobalt, iron, titanium, and chromium.
  • the thickness of the middle metal coating accounts for the shading
  • the ratio of the total thickness of the three-layer structure of the medium is 10%, 10%, 30%, 30%, 50%, 50%, 70%, 70%, 90%, 90%, the upper black light-absorbing material layer and the lower black layer
  • the ratio of the thickness of the light-absorbing material layer is 0.1:1, 0.2:1, 0.5:1, 0.8:1, 1:1, 1:1, 1.25:1, 2:1, 5:1, 10:1.
  • the front and back of the light-shielding medium of Example 93 (a layer of black light-absorbing material) has good cut-off performance for visible light. In the cut-off performance for near-infrared, the overall transmittance of the whole band is ⁇ 5%, and the reflectivity is ⁇ 4%.
  • Absorption rate>90%, high utilization rate of laser energy, the front and back of the light-shielding media (three-layer structure) of Examples 103-112 have excellent cut-off performance for visible light and good cut-off performance for near-infrared.
  • the overall full-wavelength The transmittance is ⁇ 1%, the reflectance is ⁇ 4%, and the absorptance is >95%, which is extremely efficient for laser energy.
  • the light-shielding medium (light-shielding layer) in the technical scheme provided by the present invention adopts a three-layer structure design (the upper layer is a black light-absorbing material layer, the middle layer is a metal plating layer, and the lower layer is a black light-absorbing material layer).
  • the light performance is basically not affected. But the light cut-off performance is better, especially the cut-off depth of infrared light can reach the level of OD2. At the same time, the roundness of the collimating hole is better, the light-shielding layer is not easy to break, and the reliability is higher.
  • this technical solution Compared with the collimating film in which the light-shielding medium is a single-layer metal coating, its utilization rate of laser energy is higher, the noise is further reduced, and the signal-to-noise ratio is further improved.
  • the three-layer design has the following problems: the three-layer shading design process is more complicated, the process control is more complicated, and when it is desired to adjust the collimation performance by increasing the thickness of the shading layer, the inorganic coating (such as metal coating) The deposition time is greatly increased, which has a greater impact on the cost. Therefore, in the iterative research and development process of the present invention, it is necessary to find a better way: a single-layer structure can be used to achieve the light-shielding function, and the problem of poor hole shape of the single-layer light-absorbing material layer during laser drilling can be avoided.
  • the thickness is larger than that of inorganic coating, but the laser drilling is still not round, which is essentially due to the unevenness of the coating.
  • black high-precision ink instead of ordinary black organic coating (such as ordinary black ink) can improve this unevenness and make the holes more round.
  • the collimating film sequentially includes a collimating lens layer, a flexible substrate layer and a collimating hole layer;
  • the collimating lens layer includes a microlens array and a thickness;
  • the collimating hole layer includes a light-shielding medium and a collimating hole array formed by hollowing out the light-shielding medium; the distribution of the collimating hole array and the microlens array is exactly the same, and each collimating hole is on the main optical axis of the corresponding microlens superior.
  • the collimating hole layer includes a light-shielding medium layer (light-shielding layer for short) and a collimating hole array.
  • the light-shielding medium is black high-definition ink.
  • the black high-definition ink has a single-layer (ie, one-layer) structure.
  • the light-shielding medium is a single-layer black high-definition ink.
  • the black high-definition ink includes black nanoparticles and transparent light-curable resin.
  • the black light-absorbing material is selected from one of carbon element, carbide, carbonitride, and sulfide.
  • the transparent light-curable resin is preferably an acrylic resin.
  • the particle size of the black nanoparticles is 10 nm-100 nm, for example, 10 nm, 20 nm, 30 nm, 50 nm, 80 nm, or 100 nm.
  • the light-shielding medium layer adopts wet coating (a) to attach the black high-definition ink layer 43A3 to the lower surface of the base layer.
  • the thickness of the black high-precision ink is adjusted by viscosity and coating process.
  • the black high-precision ink is finally transformed into a collimating hole layer 43 with stable performance (as shown in Figure 27) through drying (b), UV curing (c), laser opening (d) and other processes, including black The high-definition ink layer 43A3 and its micro-focusing collimation hole 43B3.
  • the finished collimation film is finally subjected to optical inspection (e), which proves that it has collimation performance.
  • the thickness t of the collimating hole layer is 3-7 ⁇ m.
  • the cut-off performance of the black high-definition ink layer to visible light and infrared light at least reaches the OD2 level, that is, the transmittance is less than or equal to 1%.
  • the method for preparing the collimating film provided by the present invention is characterized in that the collimating holes of the collimating film are perforated by a micro-focus method; in the preparation method, the light-shielding layer is made of black high-precision ink, and The laser is focused through the microlens of the collimating lens layer, and the focused light spot falls on the collimating hole layer to make a collimating hole.
  • the light-shielding medium is a single-layer black high-definition ink (also referred to as a single-layer black high-definition ink layer).
  • the light-shielding medium is a single-layer black high-definition ink (also referred to as a single-layer black high-definition ink layer).
  • Embodiments 113-125 provide a collimating film, including a collimating lens layer, a flexible base layer and a collimating hole layer, the collimating lens layer is placed on the upper surface of the base layer, and the collimating hole layer is placed on the lower surface of the base layer
  • the collimating lens layer includes a microlens array and a thickness
  • the collimating hole layer includes a light-shielding medium and a collimating hole array formed by hollowing out the medium
  • the collimating hole array is composed of a certain number of collimating holes.
  • the collimating lens array and the collimating hole array of the collimating film are all closely arranged in equilateral triangles.
  • the material of the collimating lens layer is PMMA
  • the material of the flexible substrate layer is PET
  • the shading medium of the collimating hole layer is a single layer of black high-definition ink
  • the black high-definition ink includes black nanoparticles and transparent light-curing resin.
  • the collimating film is perforated by the micro-focusing method, so that the laser is focused through the micro-lens of the collimating lens layer, and the focused light spot falls on the black high-precision ink to make collimating holes.
  • the distribution of the collimating hole array and the micro lens array It is completely consistent, the center of any collimating hole is on the main optical axis of the corresponding microlens, and the alignment is one-to-one with high precision.
  • the black nanoparticles of the black high-definition ink layer are carbon black, chromium carbide, titanium carbide, or titanium carbonitride
  • the transparent light curing resin is acrylic resin.
  • P is the minimum pitch of the main optical axis of the microlens, which is 30 ⁇ m; R is the radius of curvature of the microlens, which is 19.3 ⁇ m; H is the thickness of the collimating lens layer, which is 10.8 ⁇ m; n1 is the refractive index of the collimating lens layer, The dimensionless unit is 1.5; T is the thickness of the flexible substrate layer, which is 38 ⁇ m; n2 is the refractive index of the flexible substrate layer, and the dimensionless unit is 1.65; D is the light spot formed on the lower surface of the flexible substrate layer after focusing by a microlens The diameter is 3.6 ⁇ m; t is the thickness of the collimating hole layer, which is 3-7 ⁇ m, such as 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, or 7 ⁇ m; ⁇ is the diameter of the collimating hole, which is 3.5-5.5 ⁇ m, such as 3.5 ⁇ m, 4.0 ⁇ m, 4.5 ⁇ m, 5.0 ⁇
  • the black nanoparticles (for example, carbon black) have a particle size of 10 nm-100 nm, for example, 10 nm, 20 nm, 30 nm, 50 nm, 80 nm, or 100 nm.
  • the single-layer black high-precision ink in the collimating film provided by the present invention can realize the light-shielding function, and the holes formed by the micro-focusing method have high roundness and good hole shape, which solves the problem that the light-shielding layer adopts three
  • the problem of complex production process in layer structure and poor hole morphology after laser drilling when using single layer structure Further, the single-layer black high-definition ink in the collimating film provided by the present invention is easy to control the thickness, which solves the problem that the thickness is difficult to control when the light-shielding layer adopts a three-layer structure.
  • Figure 1 is a schematic diagram of the basic principle of a collimator device
  • Figure 2 shows the impact of the alignment accuracy of the collimation structure on the signal strength; the higher the alignment accuracy, the greater the signal strength;
  • Figure 3 shows the influence of the aspect ratio of the collimating structure on the crosstalk intensity; the higher the aspect ratio, the smaller the crosstalk intensity;
  • Figure 4 shows the drilling principle of the micro-focus method
  • Figure 5 shows the accumulation process of alignment errors of traditional punching
  • Figure 6 is a schematic cross-sectional view of a collimating film provided by the present invention.
  • Fig. 7 is a three-dimensional schematic diagram of the collimating film provided by the present invention (square arrangement);
  • Fig. 8 is a three-dimensional schematic diagram of the collimating film provided by the present invention (arranged in equilateral triangle);
  • Figure 9 is a schematic cross-sectional view of a collimating film (collimating sheet) provided by a comparative example
  • FIG. 10 is a test process of the light blocking performance (minimum light blocking angle) of the collimating film provided by the present invention.
  • Figure 11a shows the interference fringes produced by the ordered collimation structure
  • Figure 11b shows the interference fringes produced by the disordered collimation structure
  • Figure 12 is a top view of the collimating lens layer with disordered distribution (used to illustrate the meaning of disordered distribution);
  • Figure 13 is a three-dimensional schematic diagram of the interference-reducing collimating film provided by the present invention (the microlens array is disorderly distributed);
  • Figure 14 is a schematic diagram of the trend of large-screen image recognition modules (taking OLED mobile phone fingerprint recognition modules as an example);
  • Figure 15 is a schematic diagram of the architecture of the image recognition module (take an OLED mobile phone fingerprint recognition module as an example);
  • Figure 16 is a schematic diagram of the laminated collimating film and the lower part after being laminated (taking the OLED mobile phone fingerprint recognition module as an example);
  • Figure 17 shows the four-layer basic structure of the laminated collimating film
  • Figure 18 shows the influence of the thickness of the adhesive layer on the signal reception of the photoelectric sensor
  • Figure 19 is a schematic diagram of the structure of a laminated collimating film
  • Figure 20a is a schematic diagram of the transmittance comparison between the black light-absorbing material layer (43A1) and the metal plating layer (43A2);
  • Figure 20b is a schematic diagram of the reflectivity comparison between the black light-absorbing material layer (43A1) and the metal plating layer (43A2);
  • Figure 21 is a comparison of the effect of the micro-focus perforation (43B1) of the black light-absorbing material layer and the micro-focus perforation (43B2) of the metal plating layer;
  • Figure 22 shows the crater morphology formed by laser drilling of the metal coating (001 is a top view/002 is a cross-sectional view);
  • FIG. 23 is a schematic diagram of the structure of a light-shielding medium with a three-layer structure
  • Figure 24 is a schematic diagram of the transmittance and reflectivity of the shading medium with a three-layer shading design
  • 25 is a schematic diagram of the structure of a two-layer light shielding medium and a crosstalk light circuit
  • FIG. 26 is a schematic diagram of the structure of the light-shielding medium and the crosstalk light circuit of the three-layer structure
  • Figure 27 is a schematic diagram of the hole-opening process of the black high-definition ink layer
  • FIG. 28 is a schematic diagram of the structure of the collimating film provided by the present invention.
  • Figure 9 shows a collimating film for comparison, including a collimating lens layer 41, a flexible substrate layer (abbreviated as the substrate) 42 and a collimating hole layer 43.
  • the collimating lens layer is placed on the upper surface of the substrate and collimating The hole layer is placed on the bottom surface of the substrate.
  • the collimating lens layer 41 includes a microlens array 41A and a thickness 41B.
  • the collimating hole layer 43 includes a light-shielding medium 43A and a collimating hole array formed by hollowing out the medium.
  • the number of collimating holes 43B is constituted); the thickness T of the flexible base layer is 25 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all closely arranged in equilateral triangles (as shown in FIG. 8).
  • the minimum pitch P of the main optical axis of the microlens is 18 ⁇ m
  • the radius of curvature R is 12.6 ⁇ m
  • the thickness of the collimating lens layer H (the vertical distance from the apex of the microlens to the upper surface of the substrate) is 8.5 ⁇ m
  • the thickness of the collimating hole layer t is 2 ⁇ m
  • the collimating hole diameter ⁇ is 4 ⁇ m.
  • the microlens array and the thickness of the collimating lens layer are made of transparent polymer PMMA, and the refractive index n1 is 1.5.
  • the material of the flexible base layer is transparent polymer film PET, and the refractive index n2 is 1.65.
  • the light-shielding medium 43A of the collimating hole layer 43 is an inorganic plating layer of titanium carbide.
  • the collimating film uses a traditional laser drilling method (as shown in FIG. 5) to drill collimating holes 43B.
  • the main optical axis 40 of the microlens and the center of the collimating hole 43B have alignment deviations.
  • the alignment deviation of the first hole is ⁇ 1
  • the alignment deviation of the n-th hole is ⁇ n
  • ⁇ n-1 ⁇ n (n is a natural number greater than 2)
  • n is a natural number greater than 2
  • the bit deviation ⁇ exceeds 1 ⁇ m or even more.
  • the light transmittance coefficient k is easy to drop, even lower than 0.6, reaching the "poor" evaluation level.
  • the collimating film provided by the present invention includes a collimating lens layer 41, a flexible base layer 42, and a collimating hole layer 43.
  • the collimating lens layer is placed on the upper surface of the base, and the collimating hole layer is placed on the base.
  • the collimating lens layer 41 includes a microlens array 41A and a thickness 41B, and the collimating hole layer 43 includes a light-shielding medium 43A and a collimating hole array formed by hollowing out the medium (a certain number of collimating holes 43B Composition);
  • the thickness T of the flexible base layer is 25 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all closely arranged in equilateral triangles (as shown in FIG. 8).
  • the minimum pitch P of the main optical axis of the microlens is 18 ⁇ m
  • the radius of curvature R is 12.6 ⁇ m
  • the thickness H of the collimating lens layer is 8.5 ⁇ m
  • the thickness t of the collimating hole layer is 2 ⁇ m
  • the collimating hole diameter ⁇ is 4 ⁇ m .
  • the microlens array and the thickness of the collimating lens layer are made of transparent polymer PMMA, and the refractive index n1 is 1.5.
  • the material of the flexible base layer is transparent polymer film PET, and the refractive index n2 is 1.65.
  • the light-shielding medium 43A of the collimating hole layer is an inorganic plating layer of titanium carbide.
  • the collimating film adopts the micro-focus method (as shown in Figure 4) to punch collimating holes 43B.
  • the distribution of the collimating hole array and the microlens array are exactly the same, and the center of any collimating hole is in the main lens of the corresponding microlens.
  • the alignment deviation ⁇ between the center of the collimating hole and the main optical axis of the corresponding microlens is 0.47 ⁇ m, ⁇ 1 ⁇ m.
  • the laser is precisely focused on the lower surface of the PET, the spot diameter D is 1.7 ⁇ m, the minimum light blocking angle ⁇ is 7.5°, and the light transmission coefficient k is 0.98. Overall, the performance advantage of Comparative Example 1 is obvious.
  • the combination of collimating lens structure parameters is not limited to the above embodiments: for the same collimating filter effect, various changes can be made according to the material of the collimating lens layer, the refractive index, the material of the flexible substrate layer, and the refractive index. For example, change P, R, H, ⁇ , t, etc. accordingly; for the shading effect of the collimating hole of the same thickness t, various changes can be made to the shading medium, such as changing the types and combinations of organic coatings and inorganic coatings. Even proportions and so on.
  • the performance of the collimating film provided by the present invention was evaluated in the following manner.
  • the final important performance index of the collimating film is the ability to block stray light, which is generally evaluated by the smallest angle that can block oblique light.
  • the minimum angle ⁇ that can completely block the oblique light can be obtained through conventional optical simulation software (Light tools, ZeMax, Tracepro, etc.) or theoretical calculations.
  • the minimum angle test process of the collimating film According to the size of ⁇ (accurate to 0.5°), the present invention divides the light blocking performance into 5 levels, and the corresponding relationship in turn is: excellent: 0° ⁇ ⁇ 5°, excellent: 5° ⁇ 7.5°, good: 7.5° ⁇ 10°, medium: 10° ⁇ 15°), poor: ⁇ 15°.
  • Another important performance index of the collimating film is the ability to transmit signal light.
  • the alignment accuracy between the collimating hole and the microlens can be checked: when the alignment is high enough, the light spot is always within the diameter of the collimating hole, and the light transmission performance is the best at this time, and the transmittance is the largest (Using optical simulation or laser head high-precision standard sample test, generally around 90%); when the alignment error increases, the transmittance will continue to decay; because the number of collimating holes is very large, this method can be used The change in transmittance was tested under macro conditions to compare the degree of alignment.
  • the ratio of the measured transmittance to the highest transmittance (the highest transmittance refers to the light transmittance measured when the main optical axis of the microlens is completely coincident with the center line of the corresponding collimating hole) Defined as the transmittance coefficient k, which is 1 when the degree of alignment is sufficiently high.
  • the present invention divides the light transmittance performance into 5 grades, and the corresponding relationships are as follows: excellent: 1 ⁇ k>0.95, excellent: 0.95 ⁇ k>0.9, good: 0.9 ⁇ k>0.8, medium : 0.8 ⁇ k>0.6, difference: k ⁇ 0.6.
  • T% means light cut-off performance.
  • the present invention divides the cut-off performance into 5 levels according to T%, and the corresponding relationship in turn is: excellent: T% ⁇ 0.01%, excellent: T% ⁇ 0.1%, good: T% ⁇ 1%, medium: T% ⁇ 10%, bad: T% ⁇ 10%; that is, correspond to OD4, OD3, OD2, OD1, and no cutoff respectively.
  • the meaning of A% is light absorption performance.
  • the present invention divides the utilization rate of laser energy into 7 grades, and the corresponding relationship in turn is: extremely high: A%>95%, high: 95% ⁇ A %>90%, high: 90% ⁇ A%>65%, medium: 65% ⁇ A%>35%, low: 35% ⁇ A%>10%, low: 10% ⁇ A%>5% , Very low: A% ⁇ 5%;
  • the collimating lens array and the collimating hole array in the collimating film are all arranged in equilateral triangles
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible base layer 42 is PMMA.
  • the material is PET
  • the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide.
  • the collimating film uses a microlens perforation method to punch the collimating hole 43B. The other parameters are listed in Table 1.
  • Table 1 it is a relatively preferred embodiment designed with different P values on a flexible base layer with a thickness of 25 ⁇ m.
  • the P value is 10, 15, 18, 20, 25, and 30 ⁇ m
  • the focal length becomes farther, the micro-focus spot on the light-shielding layer becomes larger, so it is necessary to cooperate with the increase of H to make the focus return to the light-shielding layer, the light spot is reduced, and the matching change of R and H can make the micro-focus spot diameter D Continuously shrinking, the minimum light blocking angle ⁇ is gradually reduced, and the light blocking performance is improved.
  • the spot diameter D is to the diameter of the opening (collimation hole) ⁇ , the greater the impact of the alignment deviation ⁇ on the light transmittance, and a slight deviation will cause the loss of signal light, while D is relatively ⁇ When it is small, the impact on the position deviation is small, and it is still in the hole no matter which direction it moves.
  • the examples 1-24 provided by the present invention all have a fixed opening diameter ⁇ of 4 ⁇ m. Except that D and ⁇ in Examples 21-23 are relatively close, the other examples all maintain a certain difference, and the light transmittance coefficient k is greater than 0.9. In general, most of the examples 1-24 can reach the level of double excellent in light blocking performance and light transmission performance, which is based on the better implementation effect of the 25 ⁇ m thick flexible substrate.
  • the collimating lens array and the collimating hole array in the collimating film are both equilateral triangles and tightly arranged
  • the collimating lens layer 41 is made of PMMA
  • the flexible base layer 42 is made of It is PET
  • the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide.
  • the collimating film uses a microlens perforation method to punch the collimating hole 43B. The other parameters are listed in Table 2.
  • Examples 25-30 are Examples 25-30 with different flexible substrate thicknesses.
  • Another set of collimating films with T 25, 38, 50 ⁇ m.
  • the microlens structure When T keeps increasing, in order to maintain the micro-focusing effect (the focus always falls on the bottom surface of the substrate and the light-shielding layer and the spot is as small as possible), the microlens structure obviously needs to be shallow, that is, when the P value and the refractive index are fixed, R As the value increases, H becomes lower (compared to the difference in the embodiment in Table 1, the focal length design has been adapted as T increases, so H does not need to increase, but instead decreases). It can be found that when other conditions remain unchanged, the thickness T increases, which helps the structure become shallower, the light spot D is reduced, the minimum light blocking angle ⁇ is reduced, the light blocking performance is improved, and the light transmission coefficient is further improved.
  • T is selected from 10 to 50 ⁇ m, and more preferably 25 to 38 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all arranged in equilateral triangles closely, the material of the collimating lens layer 41 is PMMA, and the material of the flexible substrate layer 42 is PMMA. It is PET, and the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide.
  • the collimating film uses a microlens perforation method to punch the collimating hole 43B. The other parameters are listed in Table 3.
  • the opening diameter ⁇ can be reduced by adjusting the laser energy, which is not necessarily limited to a fixed value. It can be found that the opening diameter is reduced After that, the light blocking performance can be further improved, but the light transmission effect will be reduced.
  • the P value of Example 40 is 50 ⁇ m, and the corresponding R and H are both large.
  • the size of the microlens has reached the upper limit of the design, including the spot diameter D is also large (D is particularly small ,Especially less than 0.5 ⁇ m is not good, it is easy to cause the single point energy to be too high and burn the substrate), which leads to the hole diameter ⁇ reaching the upper limit of 8 ⁇ m.
  • the minimum light blocking angle ⁇ is 12 degrees and the light blocking performance is not considered. That's great.
  • P is selected from 10 to 50 ⁇ m, preferably 15 to 30 ⁇ m, and more preferably 18 to 25 ⁇ m.
  • ⁇ is selected from 1 to 10 ⁇ m (10 ⁇ m from Example 47), and more preferably 3 to 5 ⁇ m.
  • D is selected from 0.1 to 7.8 ⁇ m, preferably 0.5 to 4.9 ⁇ m, and more preferably 1 to 2 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all arranged in equilateral triangles closely, the material of the collimating lens layer 41 is PMMA, and the material of the flexible substrate layer 42 is PMMA. It is PET, and the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide.
  • the collimating film uses a microlens perforation method to punch the collimating hole 43B. The other parameters are listed in Table 4.
  • Examples 41 to 47 are Examples 41 to 47 with different collimating hole layer thickness t. Comparing the first group of Examples 41 to 44 or the second group of Examples 45 to 47, it can be seen that when other conditions remain unchanged, increasing t helps to improve the light blocking performance, and that t is too thin is not a preferred value. Since laser drilling generally forms a cavity with a smaller aspect ratio, the opening diameter is often larger than t. In fact, when t is too thick, the opening diameter will be too large (as in the second group of embodiments). Gradually reduce the light blocking performance. In the present invention, t is selected from 0.5 to 7 ⁇ m, preferably 1 to 5 ⁇ m, and more preferably 2 to 3 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all arranged in equilateral triangles
  • the material of the collimating lens layer 41 is PMMA, and further, it is cured by light Acrylic resin is polymerized, and the refractive index n1 is adjustable from 1.4 to 1.6.
  • the light-shielding medium 43A of 43 is an inorganic coating titanium carbide
  • the collimating film uses a microlens perforating method to punch a collimating hole 43B.
  • Table 5 The other parameters are listed in Table 5.
  • n1 is selected from 1.4 to 1.6, preferably 1.5.
  • n2 is selected from 1.5 to 1.65, and it is not preferred depending on the material difference.
  • the collimating lens array and the collimating hole array of the collimating film are both square and closely arranged (as shown in FIG. 7), and the material of the collimating lens layer 41 is PMMA, The material of the flexible base layer 42 is PET, the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide, and the collimating film uses a microlens perforation method to punch the collimating holes 43B.
  • the other parameters are shown in Table 6. Listed.
  • the collimating lens array and the collimating hole array of the collimating film are all arranged closely in a regular triangle, and the minimum distance P of the main optical axis of the microlenses of the collimating lens layer is 20 ⁇ m,
  • the radius of curvature R is 18.3 ⁇ m
  • the total thickness of the collimating lens layer is 4.1 ⁇ m
  • the thickness of the flexible substrate layer is 50 ⁇ m
  • the thickness of the collimating hole layer is 2 ⁇ m
  • the diameter of the collimating hole ⁇ is 4 ⁇ m.
  • the alignment error ⁇ of the microlens and the collimating hole are all ⁇ 1 ⁇ m.
  • the light blocking angle ⁇ is less than 5°, the light blocking performance is excellent, the light transmission coefficient k is all greater than 0.95, and the light transmission performance is excellent.
  • the material of the collimating lens layer, the material of the flexible base layer, and the material of the light-shielding medium of the collimating hole layer are listed in Table 7.
  • the refractive index of the collimating lens layer n1 and the refractive index of the flexible base layer n2 vary depending on the material. , And allow ⁇ 0.02 errors caused by the same material and different processes, which are no longer listed in the table.
  • the molding method is not limited to light curing, thermal curing, injection molding, hot pressing, etc.
  • the cross-section is shown in FIG. 6, and the three-dimensional view is shown in FIG.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, the main optical axis coordinates of any three overlapping microlenses are Connected to form a common triangle (not a regular triangle).
  • the main optical axis spacing P of the two overlapping microlenses changes disorderly within a certain value range (Pm ⁇ 0.5A), where the median value Pm is the amount of change A is listed in Table 8.
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible substrate layer 42 is PET
  • the light-shielding medium 43A of the collimating hole layer 43 is an inorganic coating titanium carbide
  • the collimating film adopts micro
  • the collimating hole 43B is punched by the lens punching method, and the other various parameters are listed in Table 8.
  • P is the distance between the main optical axes of two microlenses that overlap each other.
  • the value range of P is Pm ⁇ 0.5A, in ⁇ m;
  • Pm is the average of the maximum and minimum values in the range of P. Called the median value, A is the difference between the maximum value and the minimum value in the value range of P, called the amount of change, in ⁇ m;
  • R is the radius of curvature of the microlens, in ⁇ m;
  • H is the thickness of the collimating lens layer (or Called height), unit ⁇ m;
  • n1 is the refractive index of the collimating lens layer, a dimensionless unit;
  • T is the thickness of the flexible substrate layer, unit ⁇ m;
  • n2 is the refractive index of the flexible substrate layer, a dimensionless unit;
  • D is through the microlens
  • t is the thickness of the collimating
  • the collimating lens array and the collimating hole array of Example 24 are all arranged in equilateral triangles; the collimating lens array and the collimating hole array of Examples 81 to 86 are both disordered arrays and tightly arranged;
  • the collimating film changes from a fixed P value to a disorderly changing P value, which basically does not affect the performance.
  • the A value is the amount of change, selected from 1 to 10 ⁇ m, preferably 2 to 6 ⁇ m.
  • A is too small, the interference reduction effect is not obvious.
  • A is too large, the array shape becomes uncontrollable, the reproducibility is poor, and there are more light leakage areas caused by the distance too far.
  • the cross-section is shown in FIG. 6 and the three-dimensional view is shown in FIG. 13.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, the main optical axis coordinates of any three overlapping microlenses are Connected to form a common triangle (not a regular triangle).
  • the main optical axis spacing P of the two overlapping microlenses changes disorderly within a certain value range (Pm ⁇ 0.5A), where the median value Pm is the amount of change A is listed in Table 9.
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible substrate layer 42 is PET
  • the light-shielding medium 43A of the collimating hole layer 43 is inorganic coating titanium carbide
  • the collimating film adopts micro
  • the collimating hole 43B is punched by the lens punching method, and the other parameters are listed in Table 9.
  • the collimating lens array and the collimating hole array of Example 4 are all arranged in equilateral triangles; the collimating lens array and the collimating hole array of Examples 87 to 92 are all disordered arrays and are arranged closely;
  • the collimating film changes from a fixed P value of 18 ⁇ m to a disordered change (the narrowest range is 17.5 ⁇ 18.5 ⁇ m, the widest range is 13 ⁇ 23 ⁇ m). Value, basically does not affect performance.
  • the A value is the amount of change, selected from 1 to 10 ⁇ m, preferably 2 to 6 ⁇ m. When A is too small, the interference reduction effect is not obvious. When A is too large, the array shape becomes uncontrollable, the reproducibility is poor, and there are more light leakage areas caused by the distance too far.
  • the cross-sections of the collimating films provided in Examples 93 to 102 are shown in FIG. 19.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, the main optical axis coordinates of any three overlapping microlenses are Connected to form a common triangle.
  • the main optical axis spacing P of the two overlapping microlenses varies randomly within a certain value range (Pm ⁇ 0.5A), where the median value Pm is 18 ⁇ m or 15 ⁇ m, and the amount of change A Is 4 ⁇ m, that is, the value range of P is 18 ⁇ 2 ⁇ m or 15 ⁇ 2 ⁇ m, and other parameters are listed in Table 10.
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible substrate layer 42 is PET
  • the light-shielding medium 43A of the layer 43 is an inorganic coating titanium carbide.
  • the collimating film adopts a microlens perforating method to make a collimating hole 43B.
  • the other parameters are listed in Table 10.
  • the bonding adhesives of Examples 93 to 99 The layer 44 is solid OCA, and the material is a thermosetting polyacrylate system; the adhesive layer 44 of Example 100 is a high-permeability PSA, and the material is a thermosetting polyacrylate system; the adhesive layer 44 of Example 101 is a solid OCA , The material is a light-curing polyacrylate system; the adhesive layer 44 of Example 102 is a high-transmittance PSA, and the material is a light-curing polyacrylate system.
  • collimating lens arrays and collimating hole arrays of Examples 93-102 are all disordered arrays, closely arranged;
  • T 2 is the thickness of the adhesive layer, in ⁇ m
  • Examples 93 to 98 in Table 10 that when the parameters of the three-layer core structure (41, 42, 43) of the interference-reducing collimating film remain unchanged, the thickness of the adhesive layer (44) does not affect the optical collimation performance ( Light blocking performance and light transmission performance). However, if the thickness T 2 is too small, it will lead to a tight fit (regardless of the reliability before and after), and it will still cause signal light loss or crosstalk if it is too large. In particular, when the value of the thickness T 2 increases to a certain critical value, it is necessary to match a collimating film with a shallower microlens structure and a larger aspect ratio. For example, Example 98 and Example 99, a flexible substrate with a thickness of 50 ⁇ m is used.
  • any example of the ordered collimation film in the present invention can change the P value to a certain degree to obtain a new disordered collimation film. Therefore, the Pm value in the disordered collimation film is similar to that of the ordered collimation film.
  • the P value in the straight film is selected from 10 to 50 ⁇ m, preferably 15 to 30 ⁇ m, and more preferably 18 to 25 ⁇ m. In the present invention, only embodiment 24 is used for disorder optimization, and no more examples will be described for details, but this does not affect the patent scope of the disordered collimating film provided by the present invention.
  • the cross-section of the collimating film provided in Example 93 is shown in FIG. 19.
  • the collimating lens array and the collimating hole array in the collimating film are both disordered arrays, and the microlenses are closely arranged and overlap each other (as shown in FIG. 12, the main optical axis coordinates of any three overlapping microlenses are Connected to form a common triangle.
  • the main optical axis spacing P of the two overlapping microlenses varies randomly within a certain value range (Pm ⁇ 0.5A), where the median value Pm is 18 ⁇ m, and the amount of change A is 4 ⁇ m , That is, the value range of P is 18 ⁇ 2 ⁇ m, and other parameters are listed in Table 11.
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible substrate layer 42 is PET
  • the light-shielding medium 43A of the collimating hole layer 43 It is a three-layer light-shielding design.
  • the upper and lower layers are both black light-absorbing material layer 43A1, and the middle layer is metal plating layer 43A2.
  • the collimating film uses microlens perforation to make collimating holes 43B.
  • Examples 103 to 112 of the adhesive layer 44 is solid OCA, the material is thermosetting polyacrylate system; the black light-absorbing material layers of Examples 103-112 are carbon element, chromium carbide, titanium carbide, boron carbide, titanium carbonitride, boron carbonitride, and sulfide Iron, molybdenum disulfide, cobalt disulfide, nickel sulfide, and the metal coatings are aluminum, germanium, silver, copper, manganese, nickel, cobalt, iron, titanium, and chromium.
  • the thickness of the middle layer accounts for the total thickness of the three-layer structure of the shading medium
  • the ratios are 10%, 10%, 30%, 30%, 50%, 50%, 70%, 70%, 90%, 90%, and the ratio of the thickness of the upper layer and the lower layer is 0.1:1, 0.2:1, 0.5:1, 0.8:1, 1:1, 1:1, 1.25:1, 2:1, 5:1, 10:1.
  • the light-shielding medium of Example 93 has good cut-off performance for visible light on the front and back sides, and is close to In the infrared cut-off performance, the overall transmittance of the whole waveband is ⁇ 5%, the reflectivity is ⁇ 4%, and the absorptance is >90%.
  • the utilization rate of laser energy is high. Excellent cut-off performance, good cut-off performance for near-infrared, the overall full-band transmittance ⁇ 1%, reflectivity ⁇ 4%, absorption rate>95%, extremely high utilization rate of laser energy.
  • the collimating lens arrays and the collimating hole arrays of Examples 93 and 103 to 112 are all disordered arrays, closely arranged;
  • T 2 is the thickness of the adhesive layer, in ⁇ m
  • Example 93 and 103-112 in Table 11 From the comparison of Example 93 and 103-112 in Table 11, it can be seen that after the shading medium is changed to a three-layer design (the upper layer is a black light-absorbing material layer, the middle layer is a metal plating layer, and the lower layer is a black light-absorbing material layer), the straight film is aligned with the barrier.
  • the light performance and light transmission performance are basically not affected.
  • Examples 103-112 have better light cut-off performance, especially the cut-off depth of infrared light can reach the level of OD2, while the roundness of the collimating hole is better, the light shielding layer is not easy to be broken, and the reliability is higher.
  • Examples 103 to 112 have a higher utilization rate of laser energy, and the noise is further reduced, and the signal-to-noise ratio is further improved.
  • any of the above-mentioned embodiments (1 to 102) of the present invention can be implemented by adopting a three-layer design of black light-absorbing material + metal plating layer + black light-absorbing material for the shading medium, and the present invention will not list more embodiments for details. But this does not affect the patent scope of the collimating film provided by the present invention.
  • the collimating film provided in Examples 44 to 47, the cross section of which is shown in Figure 28, includes a collimating lens layer 41, a flexible base layer 42, and a collimating hole layer 43.
  • the collimating lens layer 41 is placed on the base 42 On the surface, the collimating hole layer 43 is placed on the lower surface of the base 42.
  • the collimating lens layer 41 includes a microlens array 41A and a thickness 41B.
  • the collimating hole layer 43 includes a light-shielding medium 43A and a collimator formed by hollowing out the medium.
  • a straight hole array, the collimating hole array is composed of a certain number of collimating holes 43B; the thickness T of the flexible base layer 42 is 38 ⁇ m.
  • the collimating lens array and the collimating hole array of the collimating film are all closely arranged in a regular triangle (as shown in FIG. 8), and other parameters and optical properties are listed in Table 12.
  • the material of the collimating lens layer 41 is PMMA
  • the material of the flexible substrate layer 42 is PET
  • the light-shielding medium 43A of the collimating hole layer 43 is a black high-definition ink layer 43A3, a single-layer design
  • the black high-definition ink layer contains black nano Particles and transparent light-curing resin.
  • the collimating film is perforated by the micro-focusing method, so that the laser is focused through the micro-lens of the collimating lens layer, and the focused light spot falls on the black high-definition ink to make a collimating hole 43B3 (as shown in Figure 27), collimating
  • the distribution of the hole array and the microlens array is completely consistent, and the center of any collimating hole is on the main optical axis 40 of the corresponding microlens, and the alignment is one-to-one with high precision.
  • the black nanoparticles of Examples 113 to 117 are carbon black with a particle size of 50 nm, and the transparent light-curing resin is acrylic resin.
  • the black nanoparticles of Examples 118 to 120 are chromium carbide, titanium carbide, and titanium carbonitride, respectively.
  • the thickness is 50 nm
  • the transparent light-curing resin is acrylic resin
  • the black nanoparticles of Examples 121 to 125 are carbon black
  • the particle diameters are 10, 20, 30, 80, and 100 nm, respectively
  • the transparent light-curing resin is acrylic resin.
  • the light-shielding media of Examples 113, 114, and 117-125 have excellent cut-off performance for visible light on the front and back sides, and good cut-off performance for near-infrared light. The infrared cut-off performance is excellent.
  • the opening is appropriately expanded. Hole helps to improve the performance. It can be seen from Examples 113-120 that even if there is no dense metal coating, when the thickness t of the black high-definition ink is greater than 3 ⁇ m, the cut-off depth of visible light and infrared light can reach the level of OD2, especially when the thickness t is greater than 5 ⁇ m. At that time, it can reach the level of OD3. Comparing Examples 114 and 121 to 125, it can be found that the particle size change of 10 to 100 nm has little effect on the opening, because the nanometer scale can already be sufficiently uniform.
  • any of the above-mentioned embodiments (1 to 102) of the present invention can be realized by using a single-layer black high-definition ink to realize the light-shielding medium, which provides the idea of using black high-definition ink to make holes.
  • the acrylic resin Limited to the acrylic resin, the present invention will not list more embodiments for details, but this does not affect the patent scope of the collimating film provided by the present invention.

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Abstract

本发明属于图像识别领域，尤其涉及一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组。为了解决传统准直片中两层准直光阑对位难的问题，本发明提供一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组。所述准直膜依次包括准直透镜层、柔性基体层和一层准直孔层；所述准直透镜层包含微透镜阵列；所述准直孔层包含遮光介质；所述遮光介质为单层的黑色高精细油墨。本发明提供的减干涉准直膜能够减轻光干涉现象，提高图像识别准确率。本发明提供的图像识别模组的识别准确率高，可应用于手机(OLED屏)等消费类电子产品的指纹解锁等。

Description

一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组 技术领域
本发明属于图像识别领域，尤其涉及一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜、及一种图像识别模组。
背景技术
在图像识别领域，常用的图像传感器如CMOS型或photo-TFT型，传感器模组中一般都含有准直器件，用以加强信噪比，提高识别率，减少串扰。准直器件的功能(如图1所示)主要是对图像单点像素处的漫射光进行准直过滤，形成的法向的准直光或接近准直的光(信号)，可以顺利传输到相应光电感应器处，而偏离法向的大角度光(噪音)只能极少地甚至无法进入非对应的光电感应器处，由此信噪比得以加强。
准直器件通常都具有顶部准直结构层和底部准直结构层：首先，顶层和底层双层准直结构需要精确对位，否则会大大降低信号光的强度(如图2所示)；其次，需增加顶层(入光)准直结构和底层(出光)准直结构之间距离，或缩小微结构尺寸(如图3所示)，以提高整体长径比，否则会增加串扰光的透过。
传统的准直器件一般为刚性的准直片，如光纤集束切片，或是玻璃基两侧形成的微透镜(Microlens)、准直光阑等，这类刚性准直片普遍需保持较高的厚度，一方面用以保持长径比，一方面用以保持其机械性能，防止在应用环境中破碎。然而即便如此，这类刚性准直片仍然无法满足大尺寸的图像识别模组的应用。特别是还需要压缩整体厚度的应用场合(如超薄大屏手机)，它将变得更脆，更易碎，生产良率更低，不论是性能，还是成本都无法满足需求。另外显而易见的是，此类刚性准直片更不可能在柔性图像识别模组中。
除了光纤集束类的准直片(顶层和底层准直结构本就对齐)，绝大多数刚性准直片均需要完成两层准直结构(准直光阑)的对位。然而，依次制备的两层结构要进行高精度对位，具有相当大的难度：首先，需要非常复杂、昂贵的双轴定位设备，定位过程繁琐、耗时，若准直结构尺度小于50μm(图像精度DPI>508)，点阵规模必会达到每平米上亿个点，生 产效率极其低下；其次，这种对位方式实际上精度并不高，特别是准直结构的尺寸缩小，数量增加时，累积误差会变得愈发明显，导致信号光强度下降，而频繁地原点校正也将变得更加费时。
综上，传统刚性准直片存在厚度高，厚度低的情况下易碎、性能差，两层准直结构(准直光阑)的对位难、良率低、产能低的问题，难以在大尺寸、超薄、柔性的图像识别领域中应用。
发明内容
为了解决传统刚性准直片中两层准直光阑对位难的问题，本发明提供一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组。本发明提供的准直膜只包括一层准直孔层，解决了两层准直光阑对位难的问题。与有序准直膜相比，本发明提供的减干涉准直膜能够减轻光干涉现象，提高图像识别准确率。
为了解决上述技术问题，本发明采用下述技术方案：
本发明提供一种准直膜，所述准直膜依次包括准直透镜层、柔性基体层和准直孔层。
所述准直孔层为准直光阑。
本发明提供的准直膜只包括一层准直光阑。本发明提供的准直膜只包括一层准直孔层。
所述准直膜依次包括准直透镜层、柔性基体层和一层准直孔层。
所述准直透镜层置于柔性基体的上表面，准直孔层置于柔性基体的下表面。
所述准直透镜层包含微透镜阵列和肉厚。
所述准直孔层包含准直孔阵列。
所述准直孔层包含遮光介质层和准直孔阵列。
所述准直孔层包含遮光介质和介质镂空后形成的准直孔阵列。
所述准直孔阵列与微透镜阵列的分布完全一致。每一个准直孔均在相对应微透镜的主光轴上。进一步的，每一个准直孔的圆心均在相对应微透镜的主光轴上。
所述准直膜采用微聚焦法打孔，所述准直孔阵列与微透镜阵列的分布完全一致，任意准直孔的圆心均在相应微透镜主光轴上，一对一高精度对位，对位偏差Δ<1μm。所述柔性基体层的厚度T选自10～50μm，优选为25～38μm。
所述准直透镜层的微透镜阵列为有序排布。前述准直膜称为有序准直膜(也称为有序准直结构)。前述有序排布的特点在于相邻微透镜的主光轴的间距P为一个定值。
所述准直透镜层的微透镜阵列与所述准直孔层的准直孔阵列均为有序排布。前述准直膜称为有序准直膜(也称为有序准直结构)。
进一步的，所述准直透镜层的微透镜阵列为无序排布。微透镜阵列为无序排布的准直膜称为减干涉准直膜(也称为无序准直结构，或无序阵列准直膜)。前述无序排布的特点在于相邻微透镜的主光轴的间距P为在一个范围内变化的值。与有序准直膜相比，所述减干涉准直膜能够减轻光干涉现象，提高图像识别准确率(识别率)。
进一步的，所述准直透镜层的微透镜阵列与所述准直孔层的准直孔阵列均为无序排布。前述准直膜称为减干涉准直膜(也称为无序准直结构)。
进一步的，在所述的减干涉准直膜中，在所述准直透镜层的微透镜阵列中，相邻的三个微透镜的主光轴的坐标相连形成非正三角形。非正三角形也称为普通三角形，指除三个角均为60度的三角形之外的其它的三角形。
所述准直孔阵列中的一个准直孔与微透镜阵列中的一个微透镜的位置相对应，所述微透镜的主光轴与所述准直孔的中心相重合或其偏差小于1μm。与一个准直孔位置相对应的一个微透镜称为这个准直孔的相对应微透镜。相邻的三个微透镜的主光轴的坐标相连形成正三角形(由三个互相交叠的微透镜的主光轴坐标连接而成)，或者，相邻的四个微透镜的主光轴的坐标相连形成正方形(由四个互相交叠的微透镜的主光轴坐标连接而成)。
所述微透镜阵列中的微透镜紧密排列。即相邻的微透镜相互接触或相互交叠。
所述准直膜的准直透镜阵列与准直孔阵列均为正三角形(由三个互相交叠的微透镜的主光轴坐标连接而成)紧密排列，或正方形(由四个互相交叠的微透镜的主光轴坐标连接而成)紧密排列。
进一步的，在所述准直透镜层中，相邻微透镜的主光轴的间距P为10～50μm，微透镜的半径R为6.1μm-30.2μm，准直透镜层的高度H为1.1μm-27.4μm，准直透镜层材质的折射率n1为1.4～1.6；在所述柔性基体层中，柔性基体层的厚度T为10～50μm，柔性基体层材质的折射率n2为1.5～1.65；在所述准直孔层中，准直孔层的厚度t为0.5～7μm，准直孔阵列中的准直孔的直径□为1～10μm。
在有序准直膜中，相邻微透镜的主光轴间距P均相同，P选自10～50μm，优选为15～30μm，进一步优选为18～25μm。
所述准直膜的微透镜将垂直入射的光线聚焦，在柔性基体层下表面形成直径为D的光斑，D选自0.1～7.8μm，优选为0.5～4.9μm，进一步优选为1～2μm。
所述光斑直径D由微透镜的曲率半径R(球半径R)、折射率n1、准直透镜层厚度H(微透镜顶点至基体上表面的垂直距离)以及柔性基体层的折射率n2、厚度T共同确定。
所述微透镜的曲率半径R选自6.1～30.2μm，准直透镜层厚度H选自1.1～27.4μm，R和H不做优选，依据其他参数进行适配。
所述准直透镜层(即微透镜层)折射率n1选自1.4～1.6，优选为1.5。
所述柔性基体层的折射率n2,选自1.5～1.65，依材质而异，不做优选，允许±0.02同材质不同工艺造成的误差。
所述准直膜的微透镜阵列与肉厚材质相同，材质均为透明聚合物。
进一步的，所述微透镜层的透明聚合物选自AR(Acrylic resin，丙烯酸树脂或改性丙烯酸树脂)、PC(聚碳酸酯)、PET(聚对苯二甲酸乙二醇酯)、PEN(聚萘二甲酸乙二醇酯)、PI(聚酰亚胺)、PS(聚苯乙烯)、SR(Silicon Resin，硅树脂)、FEP(全氟乙烯丙烯共聚物)或EVA(乙烯-醋酸乙烯共聚物)中的一种。进一步的，优选为，PMMA(聚甲基丙烯酸甲酯)、PC、或PS中的一种。
所述准直膜的柔性基体层为透明聚合物薄膜。
进一步的，所述透明聚合物薄膜的材质选自PET、PEN、PI、PC、PMMA(聚甲基丙烯酸甲酯)、PP(聚丙烯)、PO(聚烯烃)、SR或COP(环烯烃共聚物)中的一种。进一步的，优选为，PET、PI、PC、或PMMA中的一种。
所述准直膜的准直孔层的遮光介质为有机涂料、无机镀层中的一种或至少两种的组合。
所述遮光介质的有机涂料选自不透明聚合物油墨体系。
进一步的，所述不透明聚合物油墨体系包含吸光物质以及聚合物固化体系。
进一步的，所述吸光物质选自碳质(如碳黑、碳纤维、石墨等)、碳化物(如碳化铬、碳化钛、碳化硼等)、碳氮化物(如碳氮化钛、碳氮化硼等)、硫化物(如硫化亚铁、二硫化钼、二硫化钴、硫化镍等)中的一种或至少两种的组合。
进一步的，所述聚合物固化体系可选自丙烯酸体系(AR)、聚氨酯体系(PU)、硅树脂体系(SR)、环氧树脂体系(EP)、密胺树脂体系(MF)、酚醛树脂体系(PF)、脲醛树脂体系(UF)、或热塑性弹性材料(例如乙烯-醋酸乙烯共聚物，热塑性弹性体TPE，或热塑性聚氨酯弹性体TPU)中的一种或至少两种的组合。
进一步的，所述聚合物固化体系可选自丙烯酸树脂体系、聚氨酯体系、有机硅体系、环氧树脂体系、或热塑性弹性材料中的一种或至少两种的组合。
所述遮光介质的无机镀层选自碳单质、碳化物、碳氮化物、硫化物中的一种或至少两种的组合。
所述准直膜的准直孔层的厚度t选自0.5～7μm，优选为1～5μm，进一步优选为2～3μm。
所述准直膜的准直孔层的准直孔直径□选自1～10μm，进一步优选为3～5μm。
进一步的，所述柔性基体层厚度T可以为10μm-50μm，例如10μm，15μm，20μm，25μm，38μm或50μm。
进一步的，所述准直透镜层的相邻微透镜主光轴间距P可以为10μm-15μm，例如10μm，15μm，18μm，20μm，25μm，30μm或50μm。
进一步的，所述准直透镜层的微透镜曲率半径R可以为6.1μm-30.2μm，例如6.1μm，6.9μm，7.9μm，9.4μm，11.2μm，11.3μm，12μm，12.1μm，12.6μm，12.8μm，13.3μm，13.6μm，14μm，14.3μm，14.3μm，14.8μm，15μm，15.1μm，15.7μm，15.9μm，16μm，16.1μm，16.7μm，17μm，17.2μm，17.3μm，18μm，18.1μm，18.3μm，18.8μm，19.3μm，19.4μm，19.6μm，19.8μm，20μm，20.6μm，20.8μm，21.6μm，22.5μm，25.6μm，或30.2μm。
进一步的，所述准直透镜层厚度H可以为1.1μm-27.4μm，例如1.1μm，2.4μm，2.5μm，3.0μm，3.1μm，3.2μm，3.5μm，3.8μm，4.1μm，5.0μm，5.8μm，6.0μm，6.2μm，6.8μm，7.2μm，7.8μm，8.5μm，8.6μm，8.7μm，9.2μm，10.4μm，10.7μm，10.8μm，11μm，11.1μm，11.4μm，11.5μm，12.9μm，13.6μm，14.1μm，14.6μm，15.0μm，15.4μm，16.3μm，17.3μm，18.1μm，19.8μm，20.5μm，21.3μm，22.2μm，22.7μm，25μm，或27.4μm。
进一步的，所述微透镜在柔性基体层下表面形成的光斑直径D可以为0.1μm-7.8μm，例如0.1μm，0.3μm，0.4μm，0.5μm，0.6μm，0.7μm，0.8μm，1.0μm，1.1μm，1.2μm，1.4μm，1.5μm，1.6μm，1.7μm，1.8μm，2.0μm，2.2μm，2.4μm，2.5μm，2.6μm，2.8μm，3.1μm，3.4μm，3.6μm，3.7μm，3.9μm，4.0μm，4.9μm，或7.8μm。
进一步的，所述准直孔层的厚度t可以为0.5-7μm，例如0.5μm，1μm，2μm，3μm，4μm，5μm，或7μm。
进一步的，所述准直孔直径□可以为1-10μm，例如1μm，2μm，3μm，4μm，5μm，6μm，8μm，或10μm。
进一步的，所述准直透镜层的折射率n1可以为1.34-1.7，例如1.34，1.4，1.47，1.48，1.5，1.59，1.6，1.65，1.66，或1.7。
进一步的，所述柔性基材层的折射率n2可以为1.48-1.7，例如1.48，1.49，1.5，1.6，1.65，1.66或1.7。
进一步的，本发明提供的准直膜，包括准直透镜层(41)、柔性基体层(42)(简称为基体)和准直孔层(43)，准直透镜层置于基体的上表面，准直孔层置于基体的下表面，所述准直透镜层(41)包含微透镜阵列(41A)和肉厚(41B)，所述准直孔层(43)包含遮光介质(43A)和介质镂空后形成的准直孔阵列(由一定数量准直孔(43B)构成)。
在实施例1-24中，所述准直膜中的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层(41)的材质为PMMA，柔性基体层(42)的材质为PET，准直孔层(43)的遮光介质(43A)为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直 孔(43B)。其它各项参数如下：
P为10～30μm，R为9.4μm-20.6μm，H为3μm-27.4μm，n1为1.5；
T为25μm，n2为1.65，D为0.3～4.0μm；
t为2.0μm，□为4.0μm。进一步的，偏差Δ为0.18-0.90μm。
在实施例25-30中，所述准直膜中准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层(41)的材质为PMMA，柔性基体层(42)的材质为PET，准直孔层(43)的遮光介质(43A)为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔(43B)，所述其他各项参数如下：
P为10～25μm，R为6.1μm-19.8μm，H为2.5μm-10.7μm，n1为1.5；
T为10-50μm，n2为1.65，D为0.6～3.9μm；
t为1.0-3.0μm，□为2.0-5.0μm。进一步的，偏差Δ为0.26-0.49μm。
在实施例31-40中，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层(41)的材质为PMMA，柔性基体层(42)的材质为PET，准直孔层(43)的遮光介质(43A)为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔(43B)，其他各项参数如下：
P为10～50μm，R为16μm-30.2μm，H为1.1μm-21.3μm，n1为1.5；
T为50μm，n2为1.65，D为0.1～7.8μm；
t为0.5μm，□为1.0-8.0μm。进一步的，偏差Δ为0.21-0.88μm。
在实施例(41)-47中，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层(41)的材质为PMMA，柔性基体层(42)的材质为PET，准直孔层(43)的遮光介质(43A)为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔(43B)，其他各项参数如下：
P为30μm，R为19.3μm，H为10.8μm，n1为1.5；
T为38μm，n2为1.65，D为3.6μm；
t为0.5-7μm，□为5.0-10.0μm。进一步的，偏差Δ为0.46-0.99μm。
在实施例48-57中，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层(41)的材质为PMMA，进一步的，由光固化丙烯酸树脂聚合而成，折射率n1从1.4～1.6可调，当n2＝1.65时，柔性基体层(42)的材质为PET，当n2＝1.5时，柔性基体层(42)的材质为COP，准直孔层(43)的遮光介质(43A)为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔(43B)，其他各项参数如下：
P为20-25μm，R为15.9-22.5μm，H为3.2-9.2μm，n1为1.4-1.6；
T为38-50μm，n2为1.5-1.65，D为0.5-3.6μm；
t为2.0μm，□为4.0μm。进一步的，偏差Δ为0.25-0.66μm。
在实施例58中，所述准直膜的准直透镜阵列与准直孔阵列均为正方形紧密排列(如图7所示)，所述准直透镜层(41)的材质为PMMA，柔性基体层(42)的材质为PET，准直孔层(43)的遮光介质(43A)为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔(43B)，其他各项参数如下：
P为25μm，R为19.6μm，H为11.1μm，n1为1.5；
T为38μm，n2为1.65，D为3.9μm；
t为2.0μm，□为4.0μm。进一步的，偏差Δ为0.69μm。
本发明还提供所述准直膜的制备方法，所述的准直孔采用微聚焦法打孔。
进一步的，所述制备方法中，使激光垂直照射准直透镜层，激光通过准直透镜层的微透镜聚焦，聚焦形成的光斑落在准直孔层上打出准直孔。通过该法制备的中，所述准直孔阵列与微透镜阵列的分布完全一致，任意准直孔的圆心均在相应微透镜的主光轴上。
进一步的，所述制备方法包括下述步骤：
(1)采用透镜阵列(凹)模具，将准直透镜层在柔性基体层上表面成型(可采用光固化、热固化、热压成型等方式)，形成透镜阵列(凸)；
(2)采用湿法/干法涂布技术，在基体层下表面涂上/镀上遮光介质；
(3)采用大面积平顶激光(高斯波束整形后的平行激光)，以适当的低能量垂直照射微透镜阵列，通过每一个微透镜后均聚焦在遮光介质(即微聚焦法)，并打出相应准直孔，产生相同分布的准直孔阵列，形成准直孔层。
进一步的，所述微聚焦法包含以下特征：
(1)采用波束整形后的平顶激光作为激光源，整形后辐照面积变大，能量密度降低；
(2)必须从正面照射，较低能量密度，通过微透镜自身的微聚焦过程集中能量，实现高能量密度；
(3)微聚焦的光斑在合理范围内要足够小，焦点位置需设计在PET下表面或更深处，让能量集中于遮光层(遮光介质)；
(4)对微透镜层普适性高，不规整微透镜层，如透镜排列精度、形状精度较差、间距不均甚至无序时，同样适用。
进一步的，所述微聚焦法的过程(如图4所示)分为四个基本步骤：(a)平顶激光(5)以合适的能量(过高孔太大，甚至烧到基体，过低，打不穿孔)，打在准直膜半成品的准直透镜层(41)，微透镜(41A)实现微聚焦，肉厚(41B)实现光斑面积的预缩小，最终激 光穿过基体层(42)，在遮光介质(43A)上聚焦成极小的光斑，实现能量的高度集中；(b)由于遮光介质对光线的吸收，能量瞬间累积导致光斑位置的遮光介质被瞬间烧穿，并产生一些灰分，实际上前两步的过程仅需要微秒级别，非常迅速；(c)灰分被抽走后，露出准直孔(43B)，这些准直孔本就在微透镜主光轴(40)上，因此和微透镜(41A)高度对齐，避免了费时的对位过程，此时本发明的准直膜(4)已经是成品，包含完整的结构——准直透镜层(41)、基体层(42)、准直孔层(43)；(d)准直膜(4)此时已满足法向或接近法向的准直光高透过，在线生产时可以用普通强度的检验光源(如白光、绿光、三波灯)从微透镜面照射，光会从准直孔透出，使背面可以观察到透光孔阵列图像，并可以量化透过的光强，以此来检验打孔的品质，该过程可以轻易地在流水线上实现自动检测，特定位置抽检捕捉得到地图像也可以进行数据化分析(孔的大小、间距、阵列形态等)。
相比本发明提供的微聚焦法打孔，传统的打孔方式会有较大的局限性(如图5所示)：(a)高斯激光(7)，通过激光头的透镜组聚焦，从半成品背面方向打在遮光介质(43A)上；(b)遮光层不同位置被依次烧穿，并产生一些灰分；(c)当灰分抽走，便露出了准直孔。可以看到，整个对位过程需定位原点O(或称Mark点)，正面的CCD(Charge Coupled Device电荷耦合器件)高清摄像头对准透镜光心，背面的激光头会与正面CCD镜头联动，寻找到相应准直孔位置，从而计算出第一点与位置的初始位移量(矢量或坐标差值)，这个初始定位过程是非常耗时且复杂的，对设备要求也较高；然后，依据初始位移量和点间位移量即可计算定位出所有点位置，依次打出2～n个点，这个过程可以虽然可以利用振镜组缩短时间，然而n不可以设置太大，否则累积误差必然超过1μm，甚至会更大，特别是振镜会导致角度倾斜，光斑变大变形，误差累积越来越快；最后，当误差累积到不可接受时，需退回原点O，并重新寻找第一个点，即重复初始定位过程。纵观整个过程，虽然采用振镜组缩短时间，但由于n不可太大，需要频繁进行初始定位过程，因此导致该种方法极为耗时、复杂又依赖设备，打孔过程不仅成本高而且精度低。
进一步的，传统打孔方法的局限性还不止如此：上述定位第一个点，计算2～n的点的过程需要有一个前提条件，那就是微透镜的间距是完全准确的；事实上一方面，微透镜的模具也是通过激光打孔制备出来，必然会有误差，因此传统方式的对位误差会进一步增大，特别是模具精度并不那么高时；另一方面，有些特殊模具，所制备的不规整微透镜层，其微透镜的排列精度、形状精度较差，或设计的间距本就不均甚至无序。因此传统过程，变相又增加了微透镜层的模具精度和制备成本，导致整个准直膜成本非常高，更不用说来实现不规则微透镜层的对位打孔(而本发明的微聚焦法可以轻松实现)。
应当注意，微透镜阵列成型方式应根据透明聚合物种类和应用场合进行选择，本发明 不做优选；遮光介质的涂布方式应根据遮光介质的种类进行选择，有机涂料需选择湿法涂布方式，无机镀层需选择干法涂布(即物理气相沉积)方式。
应当注意，本发明提供的准直膜制备方法，适用于片材的生产，也适用于卷材的生产。
该准直膜可以作为柔性准直器件用于图像传感器模组。该准直膜能对图像单点像素处的漫射光进行一定程度的准直过滤，形成法向小波束光信号，并将其传输到相应光电感应器处，特别适用于大尺寸、超薄、甚至柔性的图像识别模组中。
与现有技术相比，本发明提供的准直膜，采用了厚度为10～50μm的聚合物薄膜作为柔性基体层，实现了准直器件的柔性、超薄、大尺寸化，特别适用于大尺寸、超薄、甚至柔性的图像识别模组中。
与现有技术相比，本发明提供的准直膜，采用微聚焦法打孔，所述准直孔阵列与微透镜阵列的分布完全一致，每一个准直孔的圆心均在相应微透镜的主光轴上，一对一高精度对准，对位偏差<1μm，不仅大大提高信号光的透过，允许准直结构进一步缩小(如微透镜和准直孔同步缩小)以减少串扰，提高了准直膜的信噪比，而且大大提高了生产效率，降低了成本。
与现有技术相比，本发明提供的准直膜只包括一层准直孔层，根本上解决了两层准直光阑相互之间对位难的问题，且，厚度低，韧性好、不易碎，采用微聚焦法制备得到的准直孔的圆心在相应微透镜的主光轴上、准直孔与相应微透镜对位精确。本发明提供的准直膜的制备方法易于操作，能够大量生产，提高了生产良率。本发明提供的准直膜的性能优异，能通过准直光，过滤漫射光。本发明提供的准直膜可应用于大尺寸、超薄的图像识别模组中，使大尺寸、超薄、甚至柔性的图像识别模组的量产性大大提高，当应用于手机(OLED屏)等消费类电子产品的指纹解锁方案时，因其市场需求极大，且对超薄、大屏、柔性等特性有更高追求，本发明的准直膜优势明显。
此外，有序分布的准直结构(指准直透镜层的微透镜阵列为有序排布)在实际应用中可以满足基本的图像识别要求，但存在因规整性过高产生的干涉条纹，如图11a所示。因此，有必要把准直结构优化为无序分布，破坏规整性，减弱干涉条纹，如图11b所示，以进一步提高图像识别准确率(识别率)。
本发明提供的减干涉准直膜的准直透镜层的微透镜阵列为无序排布，由于采用了微聚焦打孔方式，使得准直孔层的准直孔阵列与微透镜阵列完全一致，不仅保持了无序分布的特点，还维持了高精度的同轴对位，是传统打孔方式始终无法实现的。所述无序微透镜阵列准直膜能破坏有序微透镜阵列的规整性，减弱因规整性导致的干涉条纹(如图11b所示)，以进一步提高本发明提供的准直膜的图像识别准确率(识别率)。
所述无序阵列准直膜(减干涉准直膜)的准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形(不是正三角形))。在减干涉准直膜(无序准直膜)中，P的取值范围为5～55μm，所述互相交叠的两个微透镜的主光轴间距P在一定取值范围内无序变化，相邻主光轴间距P的变化量为A(P的取值范围中最高值与最低值的差)，相邻主光轴间距P的中值为Pm(P的取值范围中最高值与最低值的平均值)，则Pm-0.5A≤P≤Pm+0.5A；中值Pm选自10～50μm，优选为15～30μm，进一步优选为18～25μm，主光轴间距P的变化量A选自1～10μm，优选为2～6μm。
进一步的，在减干涉准直膜(无序准直膜)中，微透镜的半径R为6.1μm-30.2μm，准直透镜层的高度H为1.1μm-27.4μm，准直透镜层材质的折射率n1为1.34～1.7；在所述柔性基体层中，柔性基体层的厚度T为10～50μm，柔性基体层材质的折射率n2为1.48～1.7；在所述准直孔层中，准直孔层的厚度t为0.5～7μm，准直孔阵列中的准直孔的直径□为1～10μm。
在实施例81-86中，所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形(不是正三角形)。所述互相交叠的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，其他各项参数如下：
P为Pm±0.5A，Pm为30μm，A为1-10μm，R为20.6μm，H为27.4μm，n1为1.5；
T为25μm，n2为1.65，D为3.1μm；
t为2.0μm，□为4.0μm。进一步的，偏差Δ为0.81μm。
与现有技术相比，本发明提供的减干涉准直膜只包括一层准直孔层，根本上解决了两层准直光阑相互之间对位难的问题，且，厚度低，韧性好、不易碎，采用微聚焦法制备得到的准直孔的圆心在相应微透镜的主光轴上、准直孔与相应微透镜对位精确。本发明提供的减干涉准直膜的制备方法易于操作，能够大量生产，提高了生产良率。本发明提供的减干涉准直膜的性能优异，能通过准直光，过滤漫射光，且光干涉现象减轻。本发明提供的减干涉准直膜可应用于大尺寸、超薄的图像识别模组中，使大尺寸、超薄、甚至柔性的图像识别模组的量产性大大提高，当应用于手机(OLED屏)等消费类电子产品的指纹解锁方案时，因其市场需求极大，且对超薄、大屏、柔性等特性有更高追求，本发明的减干涉准直膜优势明显。
另一方面，本发明提供一种贴合型准直膜，所述贴合型准直膜包括贴合胶层和本发明所述的减干涉准直膜；所述贴合胶层与减干涉准直膜中的准直孔层贴合在一起。
进一步的，所述贴合胶层选自固态光学透明胶、高透光率压敏胶或透明热熔胶中的一种。
进一步的，所述贴合胶层的厚度是5～35μm。
另一方面，本发明还提供一种图像识别模组，所述图像识别模组依次包括准直层、滤光层和光电感应层；所述准直层选自本发明所述的贴合型准直膜或本发明所述的减干涉准直膜。
图14为图像识别模组大屏化趋势的示意图(以OLED手机指纹识别模组为例)，展示了四种设计的OLED手机(01)的俯视图，OLED屏幕(02)下方存在指纹识别模组(03)，手指(04)需要放置在这些特定区域方能进行识别并实现解锁：其中(a)为传统的定域识别设计，由于指纹识别模组特别小，激活屏幕时往往在该区域显示一个图标，用以指示手指精确放置的位置；(b)的指纹识别模组覆盖面积已经达到约1/4屏，从单指识别解锁拓展到双指识别解锁已不成问题；(c)、(d)的设计拟实现半屏化甚至全屏化，对指纹识别模组的大屏化提出了更高的要求。
如图15为图像识别模组的架构示意图(以OLED手机指纹识别模组为例)，在完整的指纹模组中，减干涉准直膜层(05)处于中间层位置，准直膜的上方是OLED屏幕(02)，下方还有滤光层(06)和光电感应层(07)。当准直膜是软基部件时，其尺寸稳定性(热收缩、热膨胀、褶皱等)是其弱点，因此在大面积使用时需要和下层部件进行绑定以增加整体的挺性以及厚度，下层部件可以是硬基部件(如滤光层)，也可以是与软基部件(如滤光层也可以用软基制备，光电感应芯片也可以用TFT(薄膜晶体管)制备。
本发明提供的贴合型准直膜具有贴合胶层(44)，能将软基(即柔性基体层)的准直膜与图像识别模组的下层部件进行贴合，提高了准直膜的尺寸稳定性，如图16所示。显然，经过贴合之后准直膜的平整度更高，可以减少因膜材波浪(Waving)引起的光学畸变，加强了其图像识别的准确性。
所述贴合型准直膜从上至下具有四层主要结构，分别是无序阵列准直透镜层(41)、柔性基体层(42)、准直孔层(43)以及贴合胶层(44)，如图17所示。其中，所述无序阵列准直透镜层(41)、柔性基体层(42)以及准直孔层(43)的设计参数与减干涉准直膜完全相同，所述贴合胶层(44)的厚度为T 2，选自5～50μm，优选为10～25μm，太薄胶层会导致贴合不紧密(无论信赖性前后)，太厚会导致信号光损失或串扰。如图18所示：(a)正常情况下如信号光在准直孔层聚焦后会发散在光电感应器上，产生比小孔大、但比光电感 应器小的光斑，此时信号被完全接收；(b)但如果胶层变厚导致光电感应器距离变远、光斑变大，则会产生损失；(c)当胶层过厚，光电感应器距离过远、光斑过大，甚至会产生临近光斑叠加的互相串扰现象。
进一步的，所述贴合胶层可选自固态OCA(光学透明胶)、高透PSA(压敏胶)或透明热熔胶等，优选为具有高透光率和重工性的OCA和PSA。进一步的，所述OCA和PSA的材质分别选自热固聚丙烯酸酯体系或光固聚丙烯酸酯体系。
进一步的，在贴合性型准直膜中，所述准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形(不是正三角形)。在减干涉准直膜(无序准直膜)中，P的取值范围为5～55μm，所述互相交叠的两个微透镜的主光轴间距P在一定取值范围内无序变化，相邻主光轴间距P的变化量为A(P的取值范围中最高值与最低值的差)，相邻主光轴间距P的中值为Pm(P的取值范围中最高值与最低值的平均值)，则Pm-0.5A≤P≤Pm+0.5A；中值Pm选自10～50μm，优选为15～30μm，进一步优选为18～25μm，主光轴间距P的变化量A选自1～10μm，优选为2～6μm。
进一步的，微透镜的半径R为6.1μm-30.2μm，准直透镜层的高度H为1.1μm-27.4μm，准直透镜层材质的折射率n1为1.34～1.7；在所述柔性基体层中，柔性基体层的厚度T为10～50μm，柔性基体层材质的折射率n2为1.48～1.7；在所述准直孔层中，准直孔层的厚度t为0.5～7μm，准直孔阵列中的准直孔的直径□为1～10μm。
本发明还提供所述贴合型准直膜的制备方法，所述的准直孔采用微聚焦法打孔。
进一步的，所述制备方法中，使激光垂直照射准直透镜层，激光通过准直透镜层的微透镜聚焦，聚焦形成的光斑落在准直孔层上打出准直孔。通过该法制备的贴合型准直膜中，所述准直孔阵列与微透镜阵列的分布完全一致，任意准直孔的圆心均在相应微透镜的主光轴上。
本发明还提供所述的贴合型准直膜的制备方法，所述制备方法包括下述步骤：
(1)制备减干涉准直膜；
(2)将OCA/PSA胶带撕开轻离型膜，粘合胶层与准直孔层进行贴合。
进一步的，所述制备方法包括下述步骤：
(1)制备本发明提供的减干涉准直膜；
(2)将OCA/PSA胶带撕开轻离型膜，粘合胶层与准直膜背面(准直孔层)进行贴合，通过加压、升温、抽真空进行排气、除泡；
(3)使用前撕掉重离型膜，即可获得贴合型准直膜，OCA/PSA胶层用于下层部件的 贴合。
在实施例93-102中，所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形。所述互相交叠的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化，其中，中值Pm为18μm或15μm，变化量A为4μm，即P的取值范围为18±2μm或15±2μm，其他参数如表10所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛。所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表10所列。实施例93～99的贴合胶层44为固态OCA，材质为热固化聚丙烯酸酯体系；实施例100的贴合胶层44为高透PSA，材质为热固化聚丙烯酸酯体系；实施例101的贴合胶层44为固态OCA，材质为光固化聚丙烯酸酯体系；实施例102的贴合胶层44为高透PSA，材质为光固化聚丙烯酸酯体系。其他各项参数如下：
P为Pm±0.5A，Pm为18μm，A为4μm，R为14.8μm，H为16.3μm，n1为1.5；
T为25μm，n2为1.65，D为1.1μm；
t为2μm，□为4μm。进一步的，偏差Δ为0.41μm。
或者，P为Pm±0.5A，Pm为15μm，A为4μm，R为17μm，H为2.4μm，n1为1.5；
T为50μm，n2为1.65，D为0.5μm；
t为0.5μm，□为5.0μm。进一步的，偏差Δ为0.25μm。
与现有技术相比，本发明提供的贴合型准直膜只包括一层准直孔层，根本上解决了两层准直光阑相互之间对位难的问题，且，厚度低，韧性好、不易碎，采用微聚焦法制备得到的准直孔的圆心在相应微透镜的主光轴上、准直孔与相应微透镜对位精确。本发明提供的贴合型准直膜的制备方法易于操作，能够大量生产，提高了生产良率。本发明提供的贴合型准直膜的性能优异，能通过准直光，过滤漫射光，且光干涉现象减轻。本发明提供的贴合型准直膜具有贴合胶层，能与下层部件进行贴合，提高了柔性准直膜的尺寸稳定性，减少光学畸变。本发明提供的贴合型准直膜可应用于大尺寸、超薄的图像识别模组中，使大尺寸、超薄、甚至柔性的图像识别模组的量产性大大提高，当应用于手机(OLED屏)等消费类电子产品的指纹解锁方案时，因其市场需求极大，且对超薄、大屏、柔性等特性有更高追求，本发明的贴合型准直膜优势明显。本发明提供的图像识别模组的识别准确率高，可应用于手机(OLED屏)等消费类电子产品的指纹解锁等。
应当注意，本发明准直膜中，所述准直孔层的遮光介质具有遮光功能，能将光线遮挡住，即对特定波段的光线透过率小于一定值。一般而言，对于光学传感器使用，遮光介质 的透过率至少应<1％，即截止深度(截止等级)OD 2。本发明的遮光介质采用了不透明的有机涂层和无机镀层，所含关键的物质均为吸光物质，所述吸光物质选自碳质、碳化物、碳氮化物、硫化物等。而事实上，本发明的遮光介质还可采用金属镀层，除了上述不透明的黑色吸光物质，金属镀层也可以实现遮光功能，满足透过率<1％时。金属镀层可以做的非常致密，相同厚度下，不论是截止深度(越深，透过率越小，噪音越少)还是截止范围(所截止的波长范围)都具有优势(如图20a所示)。因此，可以采用黑色吸光物质层+金属镀层+黑色吸光物质层的三层遮光设计，起到更好的遮光效果。
在图像识别模组中，不同光电感应器的感光波段是不同的，对应波段的光线必须被遮光层阻挡住，否则就会被光电感应器接收到，产生噪音。常用光电感应器中，CMOS的感光波段是400-1100nm，而TFT的感光波段是400-850nm。因此，三层遮光设计中的金属镀层针对近红外区具有深度截止特性，因而用于光电感应器是CMOS的图像识别模组中有一定优势，若单纯采用吸光物质作为遮光层(准直孔层的遮光介质形成遮光层)，那么需要增加厚度予以弥补。
三层遮光设计中的金属镀层还具有以下的优点：1、金属相比金属碳化物普遍熔点更低(大部分金属熔点小于2000℃，但碳化物往往高于3000℃，例如钛/锆的熔点为1675℃/1852℃，但是碳化钛/碳化锆的熔点分别为3160℃/3540℃)，在激光打孔时，金属会形成熔融再铸区(也称为再铸层)的圆形边界(火山口，如图22中的43B2所示)，对孔的形态管控更佳，圆度更高(当然，再铸区不一定很圆，但这不影响光线透过)，不易产生异形孔；2、金属具有延展性，薄的金属镀层具有一定柔韧性，打孔过程中不易产生裂纹、粉化等问题(金属碳化物较脆，则较易产生裂纹、粉化)，可靠性更高，如对比图21所示。
应当指出，三层遮光设计相比单层金属镀层或双层(上层黑色吸光物质层+下层金属镀层)的设计也具有一定优势：图20b展示了金属镀层的一个劣势，即反射率相比黑色吸光物质要高得多，正面的高反射率会导致激光打孔时，需要更大的能量(很多能量被反射掉)，或者需要选择合适的激光器，用金属层吸收较强烈的波段进行打孔，降低了对设备的普适性，而背面的高反射率会导致能够大角度入射的能够穿过小孔的串扰光082，在经过小孔下方的界面反射(如背胶层和滤光层的界面)回到金属镀层背面时，又再次反射，产生了0822，即小孔下方的多次反射串扰光，如图25所示。
如图23所示，若在金属镀层43A2上下均设置了黑色吸光物质43A1，激光的能量会被上层43A1大量吸收(图24反射率<4％，透过率<1％，吸收率>95％)，而转化的热量也会通过上层迅速传递到金属镀层使其受热、熔融、蒸发，从而打出准直孔，同时金属的熔融、蒸发又是一个较快的散热过程，不易使黑色吸光物质累积热量产生裂纹、粉化的问题； 而下层43A1有助于吸收小孔下方的多次反射串扰光0822，如图26所示。因此，三层遮光设计，不仅有助于准直孔的圆度提高，整体遮光层不易碎裂、可靠性更高，而且有助于提高对激光能量的利用，进一步降低噪音、提高信噪比。
三层遮光设计的制作过程相比单层遮光设计而言，在背面的制作流程上需多增加两步，即先制作上层(靠内)的黑色吸光物质层，再制作中层的金属镀层，最后制作下层(靠外)的黑色吸光物质层，为了简化流程，提高效率，黑色吸光物质优选为无机镀层，而有机涂层并非优选，如此一来，黑色吸光物质和金属均可采用干法涂布(例如物理气相沉积)的方式，对于多腔室多靶位的设备甚至可以把三层制程通过连续作业完成。如果上层和下层的黑色吸光物质相同，还可以采用往复式的卷绕镀膜设备，最少两个腔室就能完成三层制程。
进一步的，本发明提供的准直膜中，所述准直膜依次包括准直透镜层、柔性基体层和一层准直孔层；所述准直透镜层包含微透镜阵列和肉厚；所述准直孔层包含遮光介质和遮光介质镂空后形成的准直孔阵列。
所述准直孔层包含遮光介质层(简称遮光层)和准直孔阵列。
进一步的，所述遮光介质依次包括上层黑色吸光物质层、金属镀层和下层黑色吸光物质层。
进一步的，所述遮光介质依次包括上层黑色吸光物质层、金属镀层和下层黑色吸光物质层，所述上层黑色吸光物质层置于柔性基体层和金属镀层之间，所述金属镀层置于上层黑色吸光物质层和下层黑色吸光物质层之间。
所述遮光介质为三层结构，上层为黑色吸光物质层，中层为金属镀层，下层为黑色吸光物质层。
中层金属镀层的厚度在遮光介质的三层结构的总厚度中的占比为10％～90％，优选为30％～70％。上层黑色吸光物质层和下层黑色吸光物质层的厚度之比为0.1:1～10:1，优选为0.5:1～2:1。
进一步的，所述黑色吸光物质选自碳单质、碳化物、碳氮化物、硫化物中的一种。进一步的，所述金属镀层选自适用于磁控溅射的铟、锡、锌、锑、镁、铝、锶、铈、锗、镧、银、金、铜、锰、钆、镍、钴、钇、铁、钛、铂、锆、铬、铪、铌、或钼中的一种。
上层黑色吸光物质层和下层黑色吸光物质层的黑色吸光物质可以相同，也可以不同，为了制程便捷性，优选为相同。
进一步的，所述金属镀层优选锡、锌、铝、锗、银、铜、锰、镍、钴、铁、钛、铬、铌、或钼中的一种。这些金属镀膜原料更为普遍，成本低。
遮光介质的涂布方式应根据遮光介质的种类进行选择，黑色吸光物质可选择湿法涂布方式，也可选择干法涂布，优选为干法涂布方式，金属镀层需选择干法涂布(例如物理气相沉积)方式。
进一步的，本发明提供的减干涉准直膜中，所述遮光介质为三层设计，上层为黑色吸光物质层，中层为金属镀层，下层为黑色吸光物质层。
进一步的，本发明提供的贴合型准直膜中，所述遮光介质为三层设计，上层为黑色吸光物质层，中层为金属镀层，下层为黑色吸光物质层。
在实施例103-112中，所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形。所述互相交叠的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化，其中，中值Pm为18μm，变化量A为4μm，即P的取值范围为18±2μm，其他参数如表11所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为三层遮光设计，上层和下层均为黑色吸光物质43A1，中层为金属镀层43A2。所述准直膜采用微透镜打孔方式打出准直孔43B。实施例103～112的贴合胶层44为固态OCA，材质为热固化聚丙烯酸酯体系；实施例103～112的黑色吸光物质分别为碳单质、碳化铬、碳化钛、碳化硼、碳氮化钛、碳氮化硼、硫化亚铁、二硫化钼、二硫化钴、硫化镍，金属镀层分别为铝、锗、银、铜、锰、镍、钴、铁、钛、铬，中层金属镀层的厚度占遮光介质的三层结构的总厚度的比例分别为10％、10％、30％、30％、50％、50％、70％、70％、90％、90％，上层黑色吸光物质层和下层黑色吸光物质层的厚度之比分别为0.1:1、0.2:1、0.5:1、0.8:1、1:1、1:1、1.25:1、2:1、5:1、10:1。实施例93的遮光介质(为一层黑色吸光物质层)的正面和背面对可见光的截止性能良，对近红外的截止性能中，全波段整体的透过率<5％，反射率<4％，吸收率>90％，对激光能量利用率高，实施例103～112的遮光介质(为三层结构)的正面和背面对可见光的截止性能优，对近红外的截止性能良，整体全波段的透过率<1％，反射率<4％，吸收率>95％，对激光能量利用率极高。
本发明提供的技术方案中的遮光介质(遮光层)采用三层结构设计(上层为黑色吸光物质层，中层为金属镀层，下层为黑色吸光物质层)后，准直膜的挡光性能和透光性能基本没有影响。但对光线的截止性能更好，特别是对红外光的截止深度也能达到OD2的级别，同时准直孔的圆度更好，遮光层不易碎裂、可靠性更高，此外，该技术方案相比遮光介质为单层金属镀层的准直膜而言，其对激光能量的利用率更高，且噪音进一步降低，信噪比进一步提高。
应当指出，三层的设计存在下述问题：三层遮光设计工序较多，工艺管控上较为复杂， 且当希望通过遮光层的厚度提高来调节准直性能时，无机镀层(例如金属镀层)的沉积时间大大增加，对成本产生较大影响。因此，在本发明迭代研发过程中，需要寻找一种更好的方式：既可以用单层结构来实现遮光功能，又能避免激光打孔时单层吸光物质层的孔形态较差的问题。
事实上，我们发现遮光层采用普通有机涂层时，相比无机镀层厚度更大，但激光打孔仍不圆，而本质上是因为涂层的不均匀所致。采用黑色高精细油墨代替普通黑色有机涂层(例如普通黑色油墨)，能够改善这种不均匀性，使孔更圆。
进一步的，本发明提供的准直膜中，所述准直膜依次包括准直透镜层、柔性基体层和一层准直孔层；所述准直透镜层包含微透镜阵列和肉厚；所述准直孔层包含遮光介质和遮光介质镂空后形成的准直孔阵列；所述准直孔阵列与微透镜阵列的分布完全一致，每一个准直孔均在相对应微透镜的主光轴上。
所述准直孔层包含遮光介质层(简称遮光层)和准直孔阵列。
进一步的，所述遮光介质为黑色高精细油墨。所述黑色高精细油墨为单层(即一层)结构。
进一步的，所述遮光介质为单层的黑色高精细油墨。
进一步的，所述黑色高精细油墨包含黑色纳米颗粒与透明光固化树脂。
所述黑色吸光物质选自碳单质、碳化物、碳氮化物、硫化物中的一种。
所述透明光固化树脂优选为丙烯酸树脂。
进一步的，所述黑色纳米颗粒(例如炭黑)的粒径为10nm-100nm，例如为10nm、20nm、30nm、50nm、80nm、或100nm。
进一步的，所述遮光介质层采用湿法涂布(a)的方式将黑色高精细油墨层43A3附着于基体层下表面。所述黑色高精细油墨的厚度通过粘度和涂布工艺调节。所述黑色高精细油墨通过干燥(b)、UV固化(c)、激光开孔(d)等工艺过程，最终转变为性能稳定的准直孔层43(如图27所示)，包含了黑色高精细油墨层43A3及其微聚焦准直孔43B3。成品准直膜最后进行光学检验(e)，证明具有准直性能。
进一步的，所述准直孔层的厚度t为3～7μm。
进一步的，所述黑色高精细油墨层对可见光与红外光的截止性能至少达到OD2级别，即透过率小于或等于1％。
进一步的，本发明提供的准直膜的制备方法，其特征在于，所述准直膜的准直孔采用微聚焦法打孔；在所述制备方法中，遮光层采用黑色高精细油墨，并使激光通过准直透镜层的微透镜聚焦，聚焦形成的光斑落在准直孔层上打出准直孔。
进一步的，本发明提供的减干涉准直膜中，所述遮光介质为单层的黑色高精细油墨(也称为单层的黑色高精细油墨层)。
进一步的，本发明提供的贴合型准直膜中，所述遮光介质为单层的黑色高精细油墨(也称为单层的黑色高精细油墨层)。
实施例113-125提供一种准直膜，包括准直透镜层、柔性基体层和准直孔层，准直透镜层置于基体层的上表面，准直孔层置于基体层的下表面，所述准直透镜层包含微透镜阵列和肉厚，所述准直孔层包含遮光介质和介质镂空后形成的准直孔阵列，所述准直孔阵列由一定数量准直孔构成。所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列。所述准直透镜层的材质为PMMA，柔性基体层的材质为PET，准直孔层的遮光介质为单层的黑色高精细油墨，黑色高精细油墨包含黑色纳米颗粒与透明光固化树脂。所述准直膜采用微聚焦法打孔，使激光通过准直透镜层的微透镜聚焦，聚焦形成的光斑落在黑色高精细油墨上打出准直孔，准直孔阵列与微透镜阵列的分布完全一致，任意准直孔的圆心均在相应微透镜主光轴上，一对一高精度对准。所述黑色高精细油墨层的黑色纳米颗粒为炭黑、碳化铬、碳化钛、或碳氮化钛，所述透明光固化树脂为丙烯酸树脂。
其中，P为微透镜的主光轴最小间距，为30μm；R为微透镜的曲率半径，为19.3μm；H为准直透镜层厚度，为10.8μm；n1为准直透镜层的折射率，无量纲单位，为1.5；T为柔性基体层的厚度，为38μm；n2为柔性基体层的折射率，无量纲单位，为1.65；D为经过微透镜聚焦后在柔性基体层下表面形成的光斑直径，为3.6μm；t为准直孔层的厚度，为3-7μm，例如为3μm，4μm，5μm，或7μm；□为准直孔的直径，为3.5-5.5μm，例如为3.5μm，4.0μm，4.5μm，5.0μm，或5.5μm；θ为准直膜可以滤掉的最小斜射光角度，用以衡量准直滤光效果，3.5°-5.5°，例如3.5°，4°，4.5°，5°，或5.5°；k为准直膜实际透过率与最高透过率的比值，为0.80-0.90，例如为0.80，0.85，0.87，0.89，或0.90。Δ为0.35，0.45，0.5，,051，0.,6或0.7。所述黑色纳米颗粒(例如炭黑)的粒径为10nm-100nm，例如为10nm、20nm、30nm、50nm、80nm、或100nm。
本发明提供的准直膜中的单层的黑色高精细油墨能实现遮光功能，且采用微聚焦法打孔所形成的孔的孔真圆度较高，孔形态好，解决了遮光层采用三层结构时生产工艺复杂、采用单层结构时在激光打孔后孔形态较差的问题。进一步的，本发明提供的准直膜中的单层的黑色高精细油墨易于控制厚度，解决了遮光层采用三层结构时厚度难以控制的问题。
附图说明
图1为准直器件的基本原理示意图；
图2为准直结构的对位精度对信号强度的影响；对位精度越高，信号强度越大；
图3为准直结构的长径比对串扰强度的影响；长径比越高，串扰强度越小；
图4为微聚焦法打孔原理；
图5为传统打孔的对位误差累积过程；
图6为本发明所提供的准直膜横截面示意图；
图7为本发明所提供的准直膜立体示意图(正方形排列)；
图8为本发明所提供的准直膜立体示意图(正三角形排列)；
图9为对比例所提供的准直膜(准直片)横截面示意图；
图10为本发明所提供的准直膜挡光性能(最小挡光角度)测试过程；
图11a为有序准直结构产生的干涉条纹；
图11b为无序准直结构产生的干涉条纹；
图12为无序分布的准直透镜层顶视图(用于说明无序分布的含义)；
图13为本发明所提供的减干涉准直膜立体示意图(微透镜阵列为无序分布)；
图14为图像识别模组大屏化趋势的示意图(以OLED手机指纹识别模组为例)；
图15为图像识别模组的架构示意图(以OLED手机指纹识别模组为例)；
图16为贴合型准直膜与下方部件贴合后的示意图(以OLED手机指纹识别模组为例)；
图17为贴合型准直膜的四层基本结构；
图18为贴合胶层厚度对光电传感器信号接收的影响；
图19为贴合型准直膜结构示意图；
图20a为黑色吸光物质层(43A1)和金属镀层(43A2)的透过率对比示意图；
图20b为黑色吸光物质层(43A1)和金属镀层(43A2)的反射率对比示意图；
图21为黑色吸光物质层的微聚焦打孔(43B1)和金属镀层的微聚焦打孔(43B2)效果对比；
图22为金属镀层激光打孔形成的火山口形态(001为俯视图/002为截面图)；
图23为三层结构的遮光介质结构示意图；
图24为三层遮光设计的遮光介质透过率和反射率示意图；
图25为二层结构的遮光介质的结构及串扰光线路示意图；
图26为三层结构的遮光介质的结构及串扰光线路示意图；
图27为黑色高精细油墨层的开孔过程示意图；
图28为本发明提供的准直膜的结构示意图。
其中：
1：目标图像，11～17：目标图像7个连续像素点；2：准直器件，21：顶部(入光)准直结构层，22：底部(出光)准直结构层；3：光电感应芯片，31～37：7个连续像素点所对应的光电感应器；4：本发明所提供的准直膜，4’：对比例所提供的准直膜，40：准直结构的中轴(微透镜主光轴)，41：准直透镜层，41A：微透镜阵列，41B：肉厚，41C：微透镜顶点，42：柔性基体层，43：准直孔层，43A：遮光介质，43B：准直孔；5：平顶波束激光；6：检验光源；7：高斯波束激光；8：G线/H线/I线的平行光源；O：激光器定位原点；01：OLED手机，02：OLED屏幕，03：指纹识别模组，04：手指，05：减干涉准直膜层，06：红外滤光层，07：光电感应层(含光电感应芯片、柔性电路板和补强基板)，44：贴合胶层，43A1：黑色吸光物质层，43A2：金属镀层，43A3：黑色高精细油墨层，43B1：黑色吸光物质层的微聚焦打孔，43B2：金属镀层的微聚焦打孔，43B3：黑色高精细油墨层的激光微聚焦准直孔；081：未穿过小孔的串扰光；082：穿过小孔的串扰光；0821：小孔下方的直接入射串扰光；0822：小孔下方的多次反射串扰光。
具体实施方式
为了更易理解本发明的结构及所能达成的功能特征和优点，下文将本发明的较佳的实施例，并配合图式做详细说明如下。
对比例1
如图9所示为用于对比的一个准直膜，包括准直透镜层41、柔性基体层(简称基体)42和准直孔层43，准直透镜层置于基体的上表面，准直孔层置于基体的下表面，所述准直透镜层41包含微透镜阵列41A和肉厚41B，所述准直孔层43包含遮光介质43A和介质镂空后形成的准直孔阵列(由一定数量准直孔43B构成)；所述柔性基体层的厚度T为25μm。所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列(如图8所示)。所述微透镜的主光轴最小间距P为18μm，曲率半径R为12.6μm，准直透镜层厚度H(微透镜顶点至基体上表面垂直距离)为8.5μm，所述准直孔层的厚度t为2μm，准直孔直径□为4μm。所述准直透镜层的微透镜阵列与肉厚的材质均为透明聚合物PMMA，折射率n1为1.5，所述柔性基体层的材质为透明聚合物薄膜PET，折射率n2为1.65，所述准直孔层43的遮光介质43A为无机镀层碳化钛。所述准直膜采用传统激光打孔方式(如图5所示)打出一个个准直孔43B，微透镜主光轴40与准直孔43B中心位置存在对位偏差，从激光器定位原点O朝一个方向逐个打孔，第一个孔的对位偏差为Δ 1，第n个孔的对位偏差为Δ n，Δ n-1<Δ n(n为大于2的自然数)，存在n使对位偏差Δ超过1μm甚至更大。透光系数k很容易下降，甚至会低于0.6，达到“差”的评价水平。
实施例1
如图6所示为本发明提供的准直膜，包括准直透镜层41、柔性基体层42和准直孔层43，准直透镜层置于基体的上表面，准直孔层置于基体的下表面，所述准直透镜层41包含微透镜阵列41A和肉厚41B，所述准直孔层43包含遮光介质43A和介质镂空后形成的准直孔阵列(由一定数量准直孔43B构成)；所述柔性基体层的厚度T为25μm。所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列(如图8所示)。所述微透镜的主光轴最小间距P为18μm，曲率半径R为12.6μm，准直透镜层厚度H为8.5μm，所述准直孔层的厚度t为2μm,准直孔直径□为4μm。所述准直透镜层的微透镜阵列与肉厚的材质均为透明聚合物PMMA，折射率n1为1.5，所述柔性基体层的材质为透明聚合物薄膜PET，折射率n2为1.65，所述准直孔层的遮光介质43A为无机镀层碳化钛。所述准直膜采用微聚焦法打孔方式(如图4所示)打出准直孔43B，准直孔阵列与微透镜阵列的分布完全一致，任意准直孔的圆心均在相应微透镜主光轴40上，一对一高精度对准，准直孔的圆心与相对应的微透镜的主光轴的对位偏差Δ为0.47μm，<1μm。打孔时激光恰恰微聚焦在PET下表面，光斑直径D为1.7μm，最小挡光角度θ为7.5°，透光系数k为0.98，整体上与对比例1性能优势明显。
实际上，准直透镜结构参数组合并非局限上述实施例：针对同样准直滤光效果，可以根据准直透镜层的材质、折射率、柔性基体层的材质、折射率做各种各样的改变，例如相应改变P、R、H、□、t等；针对同样厚度t准直孔的遮光效果，可以对遮光介质做各种各样的改变，例如改变有机涂料、无机镀层的种类、组合、甚至比例等。
按照下述方式评价本发明提供的准直膜的性能。
(A)挡光性能
准直膜的最终重要的性能指标是挡住杂光的能力，一般用所能挡住斜射光的最小角度来评价。当准直膜各项参数确定时，可以通过常规光学模拟软件(Light tools、ZeMax、Tracepro等)，或是理论计算得出能完全遮挡住斜射光的最小角度θ。如图10所示准直膜最小角度测试过程，本发明根据θ的大小(精确到0.5°)，将挡光性能进行了5个等级的划分，依次对应关系为：极优：0°≤θ<5°、优：5°≤θ<7.5°、良：7.5°≤θ<10°、中：10°≤θ<15°)、差：θ≥15°。
(B)透光性能
准直膜另一重要的性能指标是透过信号光的能力。用垂直准直光源入射可以检验准直孔和微透镜之间的对位精度：当对齐程度足够高时，光斑始终在准直孔直径范围中，此时透光性能最好，透过率最大(利用光学模拟或激光头高精度条件下的标准样测试得到，一 般在90％附近)；当对位误差增加时透过率会不断衰减；由于准直孔数量非常大，用该方式可以在宏观条件下测试出透过率变化，以此来比较对齐程度。本发明将测试所得的透过率与最高透过率(最高透过率指微透镜的主光轴与对应的准直孔的中心线完全重合的情况下测得的光透过率)的比值定义为透光系数k，对齐程度足够高时为1。本发明根据k的大小，将透光性能进行了5个等级的划分，依次对应关系为：极优：1≥k>0.95、优：0.95≥k>0.9、良：0.9≥k>0.8、中：0.8≥k>0.6、差：k≤0.6。
显然，上述两个性能对于准直膜都是至关重要的：k越大，信号越强；θ越小，噪音越少；两个参数都对加强图像识别信噪比(SNR)有极大的帮助。
(C)光谱特性
在准直膜的设计和优化中，对重要部件提出了具体的光谱特性要求，包括针对特定波段(一般分为可见光波段和近红外波段)的透过率(Transmittance，简写成T％)和反射率(Reflectance，简写成R％)。同时，利用透过率、反射率还可以计算出吸收率(Absorbance，简写成A％)，因三者相加为100％。光谱特性的评价采用紫外-可见光-近红外分光光度计来检测，如安捷伦公司的Cary5000/7000等型号的设备都满足要求。
就遮光介质而言，T％的含义即光线截止性能，本发明根据T％，将截止性能进行了5个等级的划分，依次对应关系为：极优：T％<0.01％、优：T％<0.1％、良：T％<1％、中：T％<10％、差：T％≥10％；即分别对应OD4、OD3、OD2、OD1、以及无截止。而A％的含义即光线吸收性能，本发明根据A％，将激光能量的利用率进行了7个等级的划分，依次对应关系为：极高：A％>95％、高：95％≥A％>90％、较高：90％≥A％>65％、中等：65％≥A％>35％、较低：35％≥A％>10％、低：10％≥A％>5％、极低：A％≤5％；
实施例2-24
如实施例1提供的准直膜，所述准直膜中的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表1所列。
表1实施例1～24的设计参数和光学性能
Figure PCTCN2021074315-appb-000001
Figure PCTCN2021074315-appb-000002
注1：P为微透镜的主光轴最小间距，单位μm；R为微透镜的曲率半径，单位μm；H为准直透镜层厚度，单位μm；n1为准直透镜层的折射率，无量纲单位；T为柔性基体层的厚度，单位μm；n2为柔性基体层的折射率，无量纲单位；D为经过微透镜聚焦后在柔性基体层下表面形成的光斑直径，单位μm；t为准直孔层的厚度，单位μm；□为准直孔的直径，单位μm；θ为准直膜可以滤掉的最小斜射光角度，用以衡量准直滤光效果，单位°；k为准直膜实际透过率与最高透过率的比值，用以衡量准直孔与微透镜的对位精度。
如表1所示，为25μm厚度的柔性基底层上不同P值设计相对较优的实施例。当P值分别为10、15、18、20、25、30μm时，各有四个实施例对应。可以发现，当P值和其他 条件不变时，增加R值时，会让透镜变浅(指肉厚层的高度增加；而透镜的拱高，即透镜顶点至肉厚层上表面的高度变小)，焦距变远，遮光层上微聚焦的光斑变大，因此还需配合H的增加，使焦点回归到遮光层上，光斑缩小，R、H的配合变化，可以让微聚焦光斑直径D不断缩小，最小挡光角θ逐渐降低，挡光性能提升。针对透光性能，光斑直径D越接近开孔(准直孔)直径□时，对位偏差Δ对透光率影响越大，稍有偏离，就会产生信号光的损失，而D相对□较小时，对位偏差的影响就小，无论向哪个方向移动都仍在孔内。本发明提供的实施例1-24都固定开孔直径□为4μm，除了实施例21～23中D和□比较接近外，其他实施例均保持一定的差异，透光系数k大于0.9。总体而言，实施例1-24绝大部分都可以达到挡光性能和透光性能双优以上的水准，是基于25μm厚度柔性基底的较优实施效果。
实施例25-30
如实施例1提供的准直膜，所述准直膜中准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表2所列。
表2实施例25～30的设计参数和光学性能
Figure PCTCN2021074315-appb-000003
注1同表1。
如表2所示，为不同柔性基体厚度的实施例25～30。实施例25～27分别为P＝10μm，其他参数不变的条件下，T＝10、15、20μm的一组准直膜，实施例28～30分别为P＝25μm，其他参数不变的条件下，T＝25、38、50μm的另一组准直膜。当T不断增加时，为保持微聚焦效果(焦点始终落在基体下表面与遮光层附近且光斑尽量缩小)，微透镜结构显然需要变浅，即固定P值和折射率搭配的情况下，R值增加，H变低(相比于表1实施例的差异， 焦距设计已经随着T的增加进行适配，因而H不需要增加，反而是下降的)。可以发现，其他条件不变时，厚度T增加，有助于结构变浅，光斑D缩小，最小挡光角θ降低，挡光性能提升，且透光系数也进一步提升。因此，在厚度能允许的范围里(超薄应用越来越普遍，太厚也是不允许的)，用相对较厚的基体，对准直膜的性能提高是有帮助的，符合大长径比的准直膜性能更优的原理(如图3所示原理)。综合上述，本发明中T选自10～50μm，进一步优选为25～38μm。
实施例31-40
如实施例1提供的准直膜，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表3所列。
表3实施例31～40的设计参数和光学性能
Figure PCTCN2021074315-appb-000004
注1同表1。
如表3所示，对比实施例31～36可以发现，当其他条件不变，P值不断增大时，R值变大，若保持原深宽比，按照相似原则，焦距会变远，因而H变大。即便能控制焦距，但仍无法防止光斑半径D以及θ增加，相同开孔直径下，k也会因此下降。因此，总体而言，P值变大是不利于准直膜性能的，这也符合大长径比的准直膜性能更优的原理(如图3所示原理)。此外，对比实施例37与33，38与34，39与35，当光斑D足够小时，可以通过调整激光能量使开孔直径□减小，并不一定局限一个固定值，可以发现开孔直径降低后可 以进一步提高挡光性能，但透光效果会有所降低。实施例40的P值为50μm，相应的R和H都较大，整体而言对于本发明的准直膜而言，微透镜尺寸已经达到设计上限，包括光斑直径D也较大(D特别小，尤其是小于0.5μm也并不好，容易造成单点能量过高，烧伤基体)导致开孔直径□达到上限8μm，同时最小挡光角θ为12度也较大，挡光性能并不算太好。综合上述，本发明中P选自10～50μm，优选为15～30μm，进一步优选为18～25μm。□选自1～10μm(10μm来自实施例47)，进一步优选为3～5μm。D选自0.1～7.8μm，优选为0.5～4.9μm，进一步优选为1～2μm。
实施例41-47
如实施例1提供的准直膜，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列，所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表4所列。
表4实施例41～47的设计参数和光学性能
Figure PCTCN2021074315-appb-000005
注1同表1。
如表4所示，为不同准直孔层厚度t的实施例41～47。对比第一组实施例41～44或对比第二组实施例45～47可知，在其他条件不变时，增加t有助于提高挡光性能，t太薄并非优选值。由于激光打孔一般会形成较小深宽比的空洞，因而开孔直径往往比t要大一些，因此实际上当t太厚时，会导致开孔直径过大(如第二组实施例)反而逐渐降低挡光性能。本发明中t选自0.5～7μm，优选为1～5μm，进一步优选为2～3μm。
实施例48-57
如实施例1提供的准直膜，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧 密排列，所述准直透镜层41的材质为PMMA，进一步的，由光固化丙烯酸树脂聚合而成，折射率n1从1.4～1.6可调，当n2＝1.65时，柔性基体层42的材质为PET，当n2＝1.5时，柔性基体层42的材质为COP，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表5所列。
表5实施例48～57的设计参数和光学性能
Figure PCTCN2021074315-appb-000006
注1同表1。
如表5所示，为不同折射率搭配的实施例48～57。对比第一组实施例48～52可知，在其他条件不变时：1.增加n1(对比实施例50、48、49或对比实施例51、52)有助于缩小光斑D，降低θ并提高挡光性能，n1＝1.6时最佳，n1＝1.4时最差；2.降低n2(实施例51、52与实施例48、49对比)同样有效。对比第二组实施例53～57，折射率影响的规律仍相同，然由于第二组结构较浅，性能本就足够优异，因此影响并没有那么大。对于n1而言，太高或太低折射率的成型材料选择面会比较窄，而对于n2而言，更多的是考虑柔性基体本身的物理性能和透光率等性能，而折射率仅用于准确设计结构而已。因此，本发明中n1选自1.4～1.6，优选为1.5。n2选自1.5～1.65，依据材料差异，不做优选。
实施例58
如实施例48提供的准直膜，所述准直膜的准直透镜阵列与准直孔阵列均为正方形紧密排列(如图7所示)，所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准 直孔43B，所述其他各项参数如表6所列。
表6实施例48、58的设计参数和光学性能
Figure PCTCN2021074315-appb-000007
注1同表1。
从表6可知，当其他参数不变时，微透镜的分布方式从正三角形改为正方形，依然可以通过R、H的搭配设计，获得一款准直膜。但准直膜的性能相对于正三角形的分布稍差。主要原因是因为正方形分布没有正三角形致密，对角线与P之间的比值，正方形更大，因而相同P值，正方形排布的球冠显得更凸一些，从而导致光斑更散，D更大，同时θ上升，挡光效果变差，D变大又同时导致透光性能变差。当然，正方形排布并非不可取，为达到相同效果，需要设计更小的P值即可。本发明不再赘述更多正方形分布的实施例，正方形分布始终在本发明的保护范围内。
实施例59-80
如实施例53～57提供的准直膜，所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列，准直透镜层微透镜的主光轴最小间距P为20μm，曲率半径R为18.3μm，准直透镜层总厚4.1μm，柔性基体层厚度50μm，准直孔层厚度为2μm，准直孔直径□为4μm，所述准直膜采用微透镜打孔方式打出准直孔43B，微透镜与准直孔对位误差Δ均<1μm。挡光角度θ均小于5°，挡光性能极优，透光系数k均大于0.95，透光性能极优。所述准直透镜层的材质、柔性基体层的材质以及准直孔层遮光介质的材质如表7所列，准直透镜层折射率n1和柔性基体层折射率n2依据材质，依材质而异，且允许±0.02同材质不同工艺造成的误差，表中不再列出。
表7实施例59～80的设计参数和光学性能
Figure PCTCN2021074315-appb-000008
Figure PCTCN2021074315-appb-000009
注1同表1。
注2：对于准直透镜层同种材质，成型方式不限于光固化、热固化、注塑、热压等。
如表7所示，比较实施例59～80可知，改变材质前后，若材质的折射率相同或接近，对准直膜的性能影响不会太大。
实施例81-86
如实施例24提供的准直膜，其横截面如图6所示，立体图如图13所示。所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形(不是正三角形)。所述互相交叠的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化，其中，中值Pm， 变化量A如表8所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表8所列。
表8实施例24和实施例81-86的设计参数和光学性能
Figure PCTCN2021074315-appb-000010
注1：P为互相交叠的两个微透镜的主光轴间距，P取值范围为Pm±0.5A，单位μm；Pm为P的取值范围中的最大值与最小值的平均值，称为中值，A为P的取值范围中的最大值与最小值的差，称为变化量，单位μm；R为微透镜的曲率半径，单位μm；H为准直透镜层厚度(或称高度)，单位μm；n1为准直透镜层的折射率，无量纲单位；T为柔性基体层的厚度，单位μm；n2为柔性基体层的折射率，无量纲单位；D为经过微透镜聚焦后在柔性基体层下表面形成的光斑直径，单位μm；t为准直孔层的厚度，单位μm；□为准直孔的直径，单位μm；θ为准直膜可以滤掉的最小斜射光角度，用以衡量准直滤光效果，单位°；k为准直膜实际透过率与最高透过率的比值，用以衡量准直孔与微透镜的对位精度
注2：实施例24的准直透镜阵列与准直孔阵列均为正三角形紧密排列；实施例81～86的准直透镜阵列与准直孔阵列均为无序阵列，紧密排列；
从表8可知，当其他参数不变时，准直膜从固定P值，变成无序变化的P值，基本不影响性能。A值为变化量，选自1～10μm，优选为2～6μm。当A太小时，减干涉效果不明显，当A太大时，阵列形态变得不好控制，重现性差，且有较多因距离太远所导致的漏光区域出现。
实施例87-92
如实施例4提供的准直膜，其横截面如图6所示，立体图如图13所示。所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形(不是正三角形)。所述互相交叠 的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化，其中，中值Pm，变化量A如表9所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛，所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表9所列。
表9实施例4和实施例87-92的设计参数和光学性能
Figure PCTCN2021074315-appb-000011
注1同表8；
注2：实施例4的准直透镜阵列与准直孔阵列均为正三角形紧密排列；实施例87～92的准直透镜阵列与准直孔阵列均为无序阵列，紧密排列；
从表9可知，当其他参数不变时，准直膜从固定18μm的P值，变成无序变化(最窄17.5～18.5μm范围内，最宽13～23μm范围内无序变化)的P值，基本不影响性能。A值为变化量，选自1～10μm，优选为2～6μm。当A太小时，减干涉效果不明显，当A太大时，阵列形态变得不好控制，重现性差，且有较多因距离太远所导致的漏光区域出现。
实施例93-102
如实施例93～102提供的准直膜，其横截面如图19所示。所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形。所述互相交叠的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化，其中，中值Pm为18μm或15μm，变化量A为4μm，即P的取值范围为18±2μm或15±2μm，其他参数如表10所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为无机镀层碳化钛。所述准直膜采用微透镜打孔方式打出准直孔43B，所述其他各项参数如表10所列。实施例93～99的贴合胶层44为固态OCA，材质为热固化聚丙烯酸酯体系；实施例100的贴合胶层44为高透PSA，材质为热固化聚丙烯酸酯体系；实施例101的贴合胶层44为固 态OCA，材质为光固化聚丙烯酸酯体系；实施例102的贴合胶层44为高透PSA，材质为光固化聚丙烯酸酯体系。
表10实施例93～102的设计参数和光学性能
Figure PCTCN2021074315-appb-000012
注1同表8；
注2：实施例93～102的准直透镜阵列与准直孔阵列均为无序阵列，紧密排列；
注3：T 2为贴合胶层的厚度，单位μm；
从表10实施例93～98可知，当减干涉准直膜的三层核心结构(41、42、43)的参数不变时，贴合胶层(44)的厚度不影响光学准直性能(挡光性能和透光性能)。但厚度T 2太小时，会导致贴合不紧密(无论信赖性前后)，太大时仍会导致信号光损失或串扰。特别是，当厚度T 2的值增加到一定临界值时，需要搭配微透镜结构更浅，长径比更大的准直膜，如实施例98和实施例99，采用了50μm厚度的柔性基体层(若仍采用25μm厚度，就会发生问题)以及2.4μm的H。对比实施例97、100～102可知，当减干涉准直膜的三层核心结 构(41、42、43)的参数不变时，贴合胶层(44)的材质不影响光学准直性能。
应当理解，本发明中的任何一例有序准直膜都可以让P值进行一定程度的无序变化，获得新的无序准直膜，因此无序准直膜中的Pm值与有序准直膜中的P值，均选自10～50μm，优选为15～30μm，进一步优选为18～25μm。本发明仅以实施例24进行无序优化，不再列举更多实施例进行赘述，但这不影响本发明提供的无序准直膜的专利范围。
实施例103-112
如实施例93提供的准直膜，其横截面如图19所示。所述准直膜中准直透镜阵列与准直孔阵列均为无序阵列，且微透镜紧密排列互相交叠(如图12所示，任意三个互相交叠的微透镜的主光轴坐标连接成普通三角形。所述互相交叠的两个微透镜的主光轴间距P在一定取值范围(Pm±0.5A)内无序变化，其中，中值Pm为18μm，变化量A为4μm，即P的取值范围为18±2μm，其他参数如表11所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为三层遮光设计，上层和下层均为黑色吸光物质层43A1，中层为金属镀层43A2。所述准直膜采用微透镜打孔方式打出准直孔43B。实施例103～112的贴合胶层44为固态OCA，材质为热固化聚丙烯酸酯体系；实施例103～112的黑色吸光物质层分别为碳单质、碳化铬、碳化钛、碳化硼、碳氮化钛、碳氮化硼、硫化亚铁、二硫化钼、二硫化钴、硫化镍，金属镀层分别为铝、锗、银、铜、锰、镍、钴、铁、钛、铬，中层的厚度占遮光介质三层结构的总厚度的比例分别为10％、10％、30％、30％、50％、50％、70％、70％、90％、90％，上层和下层的厚度之比分别为0.1:1、0.2:1、0.5:1、0.8:1、1:1、1:1、1.25:1、2:1、5:1、10:1。实施例93的遮光介质正面和背面对可见光的截止性能良，对近红外的截止性能中，全波段整体的透过率<5％，反射率<4％，吸收率>90％，对激光能量利用率高，实施例103～112的遮光介质正面和背面对可见光的截止性能优，对近红外的截止性能良，整体全波段的透过率<1％，反射率<4％，吸收率>95％，对激光能量利用率极高。
表11实施例93、103～112的设计参数和光学性能
Figure PCTCN2021074315-appb-000013
注1同表8；
注2：实施例93、103～112的准直透镜阵列与准直孔阵列均为无序阵列，紧密排列；
注3：T 2为贴合胶层的厚度，单位μm；
从表11实施例93与103～112的对比可知，遮光介质改为采用三层设计(上层为黑色吸光物质层，中层为金属镀层，下层为黑色吸光物质层)后，对准直膜的挡光性能和透光性能基本没有影响。但实施例103～112对光线的截止性能更好，特别是对红外光的截止深度也能达到OD2的级别，同时准直孔的圆度更好，遮光层不易碎裂、可靠性更高，此外，实施例103～112相比遮光介质为单层金属镀层的准直膜而言，其对激光能量的利用率更高，且噪音进一步降低，信噪比进一步提高。
应当理解，本发明中上述任何一例实施例(1～102)都可以将遮光介质采用黑色吸光物质+金属镀层+黑色吸光物质的三层设计实现，本发明不再列举更多实施例进行赘述，但这不影响本发明提供的准直膜的专利范围。
实施例113～120
如实施例44～47提供的准直膜，其横截面如图28所示，包括准直透镜层41、柔性基体层42和准直孔层43，准直透镜层41置于基体42的上表面，准直孔层43置于基体42的下表面，所述准直透镜层41包含微透镜阵列41A和肉厚41B，所述准直孔层43包含遮光介质43A和介质镂空后形成的准直孔阵列，所述准直孔阵列由一定数量准直孔43B构成；所述柔性基体层42的厚度T为38μm。所述准直膜的准直透镜阵列与准直孔阵列均为正三角形紧密排列(如图8所示)，其他参数和光学性能如表12所列。所述准直透镜层41的材质为PMMA，柔性基体层42的材质为PET，准直孔层43的遮光介质43A为黑色高精细油墨层43A3，单层设计，黑色高精细油墨层包含黑色纳米颗粒与透明光固化树脂。所述准直膜采用微聚焦法打孔，使激光通过准直透镜层的微透镜聚焦，聚焦形成的光斑落在黑色高精细油墨上打出准直孔43B3(如图27所示)，准直孔阵列与微透镜阵列的分布完全一致，任意准直孔的圆心均在相应微透镜主光轴40上，一对一高精度对准。实施例113～117的黑色纳米颗粒为炭黑，粒径为50nm，透明光固化树脂为丙烯酸树脂，实施例118～120的黑色纳米颗粒分别为碳化铬、碳化钛、碳氮化钛，粒径为50nm，透明光固化树脂为丙烯酸树脂，实施例121～125的黑色纳米颗粒为炭黑，粒径分别为10、20、30、80、100nm，透明光固化树脂为丙烯酸树脂。实施例113、114、117～125的遮光介质正面和背面对可见光的截止性能优，对近红外的截止性能良，实施例115、116的遮光介质正面和背面对可见光的截止性能优，对近红外的截止性能优。
表12实施例44～47、113～120的设计参数和光学性能
Figure PCTCN2021074315-appb-000014
Figure PCTCN2021074315-appb-000015
注1：P为微透镜的主光轴最小间距，单位μm；R为微透镜的曲率半径，单位μm；H为准直透镜层厚度，单位μm；n1为准直透镜层的折射率，无量纲单位；T为柔性基体层的厚度，单位μm；n2为柔性基体层的折射率，无量纲单位；D为经过微透镜聚焦后在柔性基体层下表面形成的光斑直径，单位μm；t为准直孔层的厚度，单位μm；□为准直孔的直径，单位μm；θ为准直膜可以滤掉的最小斜射光角度，用以衡量准直滤光效果，单位°；k为准直膜实际透过率与最高透过率的比值，用以衡量准直孔与微透镜的对位精度。
从表12中的实施例44～47与113～116的对比可知，遮光介质改为采用黑色高精细油墨后，由于黑色吸光物质(黑色纳米颗粒)粒径在纳米尺度，且粒径变化范围窄，分散均匀，因此激光开孔时焦点向四周传递的能量也更均匀，相同厚度t，孔可开得更圆，因此挡光性能显著提升(由θ表征，θ越小，挡光性能越好)。对比实施例114与117可以发现，相同厚度t仍可通过激光的开孔工艺参数(如能量、频率等)按照需求扩大开孔，由于深宽比较高时透光性能有所减弱，适当扩大开孔，有助于改善该性能。由实施例113～120可知，即便没有致密的金属镀层，黑色高精细油墨在厚度t大于3μm的时候，对可见光、红外光的截止深度已经完全能达到OD2的级别，特别当厚度t大于5μm的时候，还能达到OD3的级别。对比实施例114、121～125可以发现，10～100nm的粒径变化已经对开孔影响不大，因为纳米尺度已经能足够均匀。
应当理解，本发明中上述任何一例实施例(1～102)都可以将遮光介质采用单层黑色高精细油墨来实现，提供了利用黑色高精细油墨制作孔的思路，透明光固化树脂也并不限 于丙烯酸树脂，本发明不再列举更多实施例进行赘述，但这不影响本发明提供的准直膜的专利范围。
应当注意，以上所述，仅为本发明的几种典型的实施例而已，并非用于限定本发明的保护范围。凡是根据本发明内容所做的均等变化与修饰，均涵盖在本发明的专利范围内。

Claims (10)

  1. 一种准直膜，其特征在于，所述准直膜依次包括准直透镜层、柔性基体层和一层准直孔层；所述准直透镜层包含微透镜阵列和肉厚；所述准直孔层包含遮光介质和遮光介质镂空后形成的准直孔阵列；所述准直孔阵列与微透镜阵列的分布完全一致，每一个准直孔均在相对应微透镜的主光轴上。
  2. 根据权利要求1所述的准直膜，其特征在于，所述准直透镜层的微透镜阵列为有序排布。
  3. 根据权利要求1所述的准直膜，其特征在于，所述遮光介质为单层的黑色高精细油墨。
  4. 根据权利要求3所述的准直膜，其特征在于，所述黑色高精细油墨包含黑色纳米颗粒与透明光固化树脂。
  5. 根据权利要求4所述的准直膜，其特征在于，所述黑色纳米颗粒选自碳单质、碳化物、碳氮化物、硫化物中的一种，粒径选自10～100nm；所述透明光固化树脂为丙烯酸树脂。
  6. 一种减干涉准直膜，其特征在于，所述减干涉准直膜选自权利要求1、3、4或5中所述的准直膜，其中，所述准直透镜层的微透镜阵列为无序排布。
  7. 根据权利要求6所述的减干涉准直膜，其特征在于，所述微透镜阵列中的微透镜紧密排列；在所述准直透镜层的微透镜阵列中，相邻的三个微透镜的主光轴的坐标相连形成非正三角形；在所述准直透镜层中，相邻微透镜的主光轴的间距P为5～55μm，相邻微透镜的主光轴间距P的变化量为A，主光轴间距P的中值为Pm，则Pm-0.5A≤P≤Pm+0.5A；所述Pm为10～50μm，所述主光轴间距P的变化量A为1～10μm；微透镜的半径R为6.1μm-30.2μm，准直透镜层的高度H为1.1μm-27.4μm，准直透镜层材质的折射率n1为1.34～1.7；
    在所述柔性基体层中，柔性基体层的厚度T为10～50μm，柔性基体层材质的折射率n2为1.48～1.7；
    在所述准直孔层中，准直孔层的厚度t为0.5～7μm，准直孔阵列中的准直孔的直径□为1～10μm。
  8. 一种贴合型准直膜，其特征在于，所述贴合型准直膜包括贴合胶层和权利要求6或7中任一项所述的减干涉准直膜；所述贴合胶层与减干涉准直膜中的准直孔层贴合在一起。
  9. 一种图像识别模组，其特征在于，所述图像识别模组依次包括准直层、滤光层和光电感应层；所述准直层选自权利要求8所述的贴合型准直膜或权利要求6或7所述的减干涉准直膜。
  10. 根据权利要求6或7所述的减干涉准直膜的制备方法，其特征在于，所述准直膜的准直孔采用微聚焦法打孔；在所述制备方法中，使激光垂直照射准直透镜层，激光通过准直透镜层的微透镜聚焦，聚焦形成的光斑落在准直孔层上打出准直孔。
PCT/CN2021/074315 2020-02-24 2021-01-29 一种准直膜、一种减干涉准直膜及其制备方法、一种贴合型准直膜及一种图像识别模组 WO2021169725A1 (zh)

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