CN211857087U

CN211857087U - Interference reducing collimation film

Info

Publication number: CN211857087U
Application number: CN202020206263.9U
Authority: CN
Inventors: 李刚; 夏寅; 付坤; 高斌基; 王小凯; 陈建文; 唐海江; 张彦
Original assignee: Ningbo Exciton Technology Co Ltd
Current assignee: Ningbo Exciton Technology Co Ltd
Priority date: 2020-02-24
Filing date: 2020-02-25
Publication date: 2020-11-03
Anticipated expiration: 2030-02-25
Also published as: CN113376851B; CN113296282B; CN113376847B; CN113376847A; CN113296172A; CN113296169A; WO2021169726A1; CN113376850B; CN113376849B; CN113296173B; CN113376851A; CN113296171A; CN113376848A; CN113296170B; CN113296279B; CN113376718A; CN113296279A; CN113296170A; CN113296280A; CN113296172B

Abstract

The utility model belongs to the image recognition field especially relates to a collimation membrane and one kind subtracts interference collimation membrane and preparation method thereof. In order to solve the problem that two layers of collimating diaphragms are difficult to align in the traditional rigid collimating sheet, the utility model provides a collimating film and a preparation method thereof. The collimating film sequentially comprises 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 aperture layer comprises an array of collimating apertures. The micro-lens array of the collimating lens layer is arranged in disorder. The utility model provides a collimation membrane only includes one deck collimation porose layer, has solved the difficult problem of two-layer collimation diaphragm counterpoint. Compared with the ordered collimating film, the interference reducing collimating film can reduce the phenomenon of light interference and improve the accuracy of image recognition.

Description

Interference reducing collimation film

Technical Field

The utility model belongs to the image recognition field especially relates to a collimation membrane, reaches an interference reduction collimation membrane.

Background

In the field of image recognition, a common image sensor such as a CMOS type or a photo-TFT type generally includes a collimator device in a sensor module to enhance a signal-to-noise ratio, improve a recognition rate, and reduce crosstalk. The collimating device (as shown in fig. 1) mainly collimates and filters diffused light at a single-point pixel of an image, and the formed normal collimated light or nearly collimated light (signal) can be smoothly transmitted to a corresponding photoelectric sensor, while light (noise) with a large angle deviating from the normal direction can only rarely or even cannot enter a non-corresponding photoelectric sensor, so that the signal-to-noise ratio is enhanced.

The collimating devices typically have a top collimating structure layer and a bottom collimating structure layer: first, the top and bottom double-layer collimating structures need to be aligned precisely, otherwise the intensity of the signal light is greatly reduced (as shown in fig. 2); secondly, the distance between the top (incident) and bottom (emergent) collimating structures needs to be increased, or the size of the microstructure needs to be reduced (as shown in fig. 3) to increase the overall aspect ratio, otherwise the transmission of crosstalk light will be increased.

The traditional collimating device is generally a rigid collimating sheet, such as an optical fiber bundle slice, or a Microlens (Microlens), a collimating diaphragm and the like formed on two sides of a glass substrate, and the rigid collimating sheet generally needs to keep higher thickness, on one hand, the rigid collimating sheet is used for keeping the length-diameter ratio, on the other hand, the rigid collimating sheet is used for keeping the mechanical property of the rigid collimating sheet and preventing the rigid collimating sheet from being broken in an application environment. However, even then, such rigid collimating sheet still cannot satisfy the application of large-sized image recognition module. In particular, applications requiring a reduced overall thickness (e.g., ultra-thin, large screen handsets) become more fragile, and less productive, both performance and cost. It is also apparent that such rigid collimating sheets are less likely to be in a flexible image recognition module.

Except for the optical fiber bundle type collimating sheets (the top layer collimating structure and the bottom layer collimating structure are aligned originally), most of the rigid collimating sheets need to complete the alignment of two layers of collimating structures (collimating diaphragms). However, the two-layer structure prepared in sequence needs to be aligned with high precision, which has considerable difficulty: firstly, very complex and expensive double-shaft positioning equipment is needed, the positioning process is complicated and time-consuming, if the collimation structure size is less than 50 micrometers (image precision DPI >508), the lattice scale can reach hundreds of millions of points per square meter, and the production efficiency is extremely low; secondly, the alignment method is not accurate in practice, and especially when the size of the collimating structure is reduced and the number of collimating structures is increased, the accumulated error becomes more obvious, which results in the decrease of signal light intensity, and frequent origin correction becomes more time-consuming.

In conclusion, the traditional rigid collimating sheet has the problems of high thickness, fragility and poor performance under the condition of low thickness, difficult alignment of two layers of collimating structures (collimating diaphragms), low yield and low productivity, and is difficult to apply to the field of large-size, ultrathin and flexible image recognition.

Disclosure of Invention

In order to solve the difficult problem of two-layer collimation diaphragm counterpoint in the traditional rigidity collimation piece, the utility model provides a collimation membrane and one kind subtract and interfere collimation membrane. The utility model provides a collimation membrane only includes one deck collimation porose layer, has solved the difficult problem of two-layer collimation diaphragm counterpoint. Compare with orderly collimation membrane, the utility model provides a subtract and interfere collimation membrane can alleviate the light interference phenomenon, improves the image recognition rate of accuracy.

In order to solve the technical problem, the utility model discloses a following technical scheme:

the utility model provides a collimation membrane, collimation membrane includes collimation lens layer, flexible base member layer and collimation porose layer in proper order.

The collimation hole layer is a collimation diaphragm.

The utility model provides a collimation membrane only includes one deck collimation diaphragm. The utility model provides a collimation membrane only includes one deck collimation porose layer.

The collimating film sequentially comprises a collimating lens layer, a flexible substrate layer and a collimating hole layer.

The collimating lens layer is arranged on the upper surface of the flexible substrate, and the collimating hole layer is arranged on the lower surface of the flexible substrate.

The collimating lens layer includes a microlens array and a thickness.

The collimating aperture layer comprises an array of collimating apertures.

The collimation hole layer comprises a shading medium layer and a collimation hole array.

The collimation hole layer comprises a shading medium and a collimation hole array formed after the medium is hollowed out.

The distribution of the collimation hole array and the micro-lens array is completely consistent. Each collimating aperture is on the primary optical axis of the corresponding microlens. Furthermore, the center of each collimating hole is on the main optical axis of the corresponding microlens.

The collimating film is punched by adopting a micro-focusing method, the distribution of the collimating hole array is completely consistent with that of the micro-lens array, the circle centers of any collimating hole are all positioned on the main optical axis of the corresponding micro-lens, one-to-one high-precision alignment is carried out, and the alignment deviation delta is less than 1 mu m. The thickness T of the flexible substrate layer is 10-50 μm, preferably 25-38 μm.

The micro-lens array of the collimating lens layer is orderly arranged. The foregoing collimating films are referred to as ordered collimating films (also known as ordered collimating structures). The foregoing ordered arrangement is characterized in that the pitch P of the principal optical axes of adjacent microlenses is a constant value.

The micro-lens array of the collimation lens layer and the collimation hole array of the collimation hole layer are arranged in sequence. The foregoing collimating films are referred to as ordered collimating films (also known as ordered collimating structures).

Further, the micro-lens array of the collimating lens layer is arranged in a disordered manner. The collimating film in which the microlens array is arranged in a disordered manner is called a subtractive interference collimating film (also called a disordered collimating structure, or a disordered array collimating film). The foregoing disordered arrangement is characterized in that the pitch P of the principal optical axes of adjacent microlenses is a value that varies within a range. Compared with the ordered collimating film, the interference reducing collimating film can reduce the phenomenon of light interference and improve the accuracy (recognition rate) of image recognition.

Further, the micro-lens 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 referred to as a subtractive interference collimating film (also referred to as a disordered collimating structure).

Further, in the interference reduction collimation film, in the microlens array of the collimation lens layer, the coordinates of the main optical axes of the three adjacent microlenses are connected to form a non-regular triangle.

One collimating hole in the collimating hole array corresponds to the position of one microlens in the microlens array, and the main optical axis of the microlens coincides with the center of the collimating hole or the deviation of the main optical axis and the center of the collimating hole is less than 1 μm. One microlens corresponding to one alignment hole position is referred to as a corresponding microlens of this alignment hole. The coordinates of the main optical axes of three adjacent microlenses are connected to form a regular triangle (formed by connecting the coordinates of the main optical axes of three mutually overlapped microlenses), or the coordinates of the main optical axes of four adjacent microlenses are connected to form a square (formed by connecting the coordinates of the main optical axes of four mutually overlapped microlenses).

The microlenses in the microlens array are closely arranged. I.e., 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 in regular triangle (formed by connecting the coordinates of the main optical axes of three mutually overlapped micro lenses) close arrangement or square (formed by connecting the coordinates of the main optical axes of four mutually overlapped micro lenses) close arrangement.

Furthermore, in the collimating lens layer, the distance P between the main optical axes of the adjacent micro lenses is 10-50 μm, the radius R of the micro lenses is 6.1-30.2 μm, the height H of the collimating lens layer is 1.1-27.4 μm, and the refractive index n1 of the collimating lens layer material is 1.4-1.6; in the flexible substrate layer, the thickness T of the flexible substrate layer is 10-50 mu m, and the refractive index n2 of the flexible substrate layer material is 1.5-1.65; in the collimation hole layer, the thickness t of the collimation hole layer is 0.5-7 μm, and the diameter phi of collimation holes in the collimation hole array is 1-10 μm.

In the ordered collimating film, the pitches P of the main optical axes of the adjacent microlenses are the same, and P is selected from 10 to 50 μm, preferably 15 to 30 μm, and more preferably 18 to 25 μm.

The micro lens of the collimating film focuses vertically incident light rays, and light spots with the diameter D are formed on the lower surface of the flexible substrate layer, wherein D is selected from 0.1-7.8 micrometers, preferably 0.5-4.9 micrometers, and further preferably 1-2 micrometers.

The spot diameter D is determined by the curvature radius R (spherical radius R) of the microlens, the refractive index n1, the collimating lens layer thickness H (vertical distance from the apex of the microlens to the upper surface of the substrate), and the refractive index n2 and the thickness T of the flexible substrate layer.

The curvature radius R of the micro lens is selected from 6.1-30.2 mu m, the thickness H of the collimating lens layer is selected from 1.1-27.4 mu m, R and H are not preferred, and the micro lens is adapted according to other parameters.

The refractive index n1 of the collimating lens layer (i.e. the micro lens layer) is selected from 1.4-1.6, and preferably 1.5.

The refractive index n2 of the flexible substrate layer is selected from 1.5-1.65, and is different according to materials, is not preferred, and allows errors caused by different processes of plus or minus 0.02 same materials.

The micro-lens array of the collimating film is made of the same material as the thick meat, and the material is transparent polymer.

Further, the transparent polymer of the microlens layer is selected from one of 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 preferable that the material is one of PMMA (polymethyl methacrylate), PC, or PS.

The flexible matrix layer of the collimating film is a transparent polymer film.

Further, the material of the transparent polymer film is selected from one of PET, PEN, PI, PC, PMMA (polymethyl methacrylate), PP (polypropylene), PO (polyolefin), SR, or COP (cyclic olefin copolymer). Further, one of PET, PI, PC, and PMMA is preferable.

The shading medium of the collimation hole layer of the collimation film is one or the combination of at least two of organic paint and inorganic plating.

The organic coating of the opacifying medium is selected from opaque polymeric ink systems.

Further, the opaque polymeric ink system comprises a light absorbing material and a polymeric curing system.

Further, the light absorbing material is selected from one or a combination of at least two of carbon (such as carbon black, carbon fiber, graphite, etc.), carbide (such as chromium carbide, titanium carbide, boron carbide, etc.), carbonitride (such as titanium carbonitride, boron carbonitride, etc.), sulfide (such as ferrous sulfide, molybdenum disulfide, cobalt disulfide, nickel sulfide, etc.).

Further, the polymer curing system may be selected from one or a combination of at least two of acrylic systems (AR), polyurethane systems (PU), silicone Systems (SR), epoxy systems (EP), melamine resin systems (MF), phenolic resin systems (PF), urea resin systems (UF), or thermoplastic elastomeric materials (e.g. ethylene-vinyl acetate copolymers, thermoplastic elastomers TPE, or thermoplastic polyurethane elastomers TPU).

Further, the polymer curing system may be selected from one or a combination of at least two of an acrylic resin system, a polyurethane system, a silicone system, an epoxy resin system, or a thermoplastic elastomer.

The inorganic coating of the shading medium is selected from one or the combination of at least two of simple carbon, carbide, carbonitride and sulfide.

The thickness t of the collimation hole layer of the collimation film is selected from 0.5-7 μm, preferably 1-5 μm, and further preferably 2-3 μm.

The diameter phi of the collimation hole layer of the collimation film is selected from 1-10 mu m, and the preferred diameter phi is 3-5 mu m.

Further, the flexible matrix layer thickness T may be 10 μm to 50 μm, such as 10 μm, 15 μm, 20 μm, 25 μm, 38 μm or 50 μm.

Further, the chief optical axis pitch P of adjacent microlenses of the collimating lens layer may be 10 μm to 15 μm, such as 10 μm, 15 μm, 18 μm, 20 μm, 25 μm, 30 μm, or 50 μm.

Further, the radius of curvature R of the microlenses of the collimating lens layer can be 6.1 μm to 30.2 μm, such as 6.1 μm, 6.9 μm, 7.9 μm, 9.4 μm, 11.2 μm, 11.3 μm, 12 μm, 12.1 μm, 12.6 μm, 12.8 μm, 13.3 μm, 13.6 μm, 14 μm, 14.3 μm, 14.3 μm, 14.8 μm, 15 μm, 15.1 μm, 15.7 μm, 15.9 μm, 16 μm, 16.1 μm, 16.7 μm, 17 μm, 17.2 μm, 17.3 μm, 18 μm, 18.1 μm, 18.3 μm, 18.8 μm, 19.3 μm, 19.4 μm, 19.6 μm, 19.8 μm, 20.3 μm, 20.6 μm, 20.5 μm, 22.5 μm, or 22.6 μm.

Further, the collimating lens layer thickness H may be 1.1 μm to 27.4 μm, such as 1.1 μm, 2.4 μm, 2.5 μm, 3.0 μm, 3.1 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4.1 μm, 5.0 μm, 5.8 μm, 6.0 μm, 6.2 μm, 6.8 μm, 7.2 μm, 7.8 μm, 8.5 μm, 8.6 μm, 8.7 μm, 9.2 μm, 10.4 μm, 10.7 μm, 10.8 μm, 11 μm, 11.1 μm, 11.4 μm, 11.5 μm, 12.9 μm, 13.6 μm, 14.1 μm, 14.6 μm, 15.0 μm, 15.4 μm, 16.4 μm, 11.5 μm, 12.9 μm, 13.6 μm, 14.1 μm, 14.6 μm, 15.0 μm, 15.4 μm, 3.2 μm, 22.2 μm, 22.5 μm, 2 μm, or 22.2 μm.

Further, the diameter D of the light spot formed by the micro-lenses on the lower surface of the flexible substrate layer may be 0.1 μm to 7.8 μm, such as 0.1 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 1.0 μm, 1.1 μm, 1.2 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 2.0 μm, 2.2 μm, 2.4 μm, 2.5 μm, 2.6 μm, 2.8 μm, 3.1 μm, 3.4 μm, 3.6 μm, 3.7 μm, 3.9 μm, 4.0 μm, 4.9 μm, or 7.8 μm.

Further, the thickness t of the collimating aperture layer may be 0.5-7 μm, such as 0.5 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, or 7 μm.

Further, the collimating aperture diameter φ may be 1-10 μm, such as 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 8 μm, or 10 μm.

Further, the collimating lens layer may have a refractive index n1 of 1.34-1.7, such as 1.34, 1.4, 1.47, 1.48, 1.5, 1.59, 1.6, 1.65, 1.66, or 1.7.

Further, 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.

Further, the utility model provides a collimating film, including collimating lens layer (41), flexible base member layer (42) (the base member for short) and collimation hole layer (43), the upper surface of base member is arranged in to the collimating lens layer, and the lower surface of base member is arranged in to the collimation hole layer, collimating lens layer (41) contain microlens array (41A) and thickness of meat (41B), collimation hole layer (43) contain the collimation hole array (constitute by a certain amount collimation hole (43B) that form behind shading medium (43A) and the medium fretwork).

In examples 1 to 24, the collimating lens array and the collimating aperture array in the collimating film are both arranged in a regular triangle, the collimating lens layer (41) is made of PMMA, the flexible substrate layer (42) is made of PET, the light-shielding medium (43A) of the collimating aperture layer (43) is inorganic plated titanium carbide, and the collimating film is perforated with collimating apertures (43B) in a microlens perforation manner. The other parameters are as follows:

p is 10-30 μm, R is 9.4-20.6 μm, H is 3-27.4 μm, and n1 is 1.5;

t is 25 μm, n2 is 1.65, and D is 0.3-4.0 μm;

t is 2.0 μm and phi is 4.0 μm. Further, the deviation Δ is 0.18 to 0.90 μm.

In embodiments 25 to 30, the collimating lens array and the collimating aperture array in the collimating film are both arranged in a regular triangle, the collimating lens layer (41) is made of PMMA, the flexible substrate layer (42) is made of PET, the light-shielding medium (43A) of the collimating aperture layer (43) is inorganic plated titanium carbide, the collimating film punches the collimating aperture (43B) in a microlens punching manner, and the other parameters are as follows:

p is 10-25 μm, R is 6.1-19.8 μm, H is 2.5-10.7 μm, n1 is 1.5;

t is 10-50 μm, n2 is 1.65, and D is 0.6-3.9 μm;

t is 1.0-3.0 μm, and phi is 2.0-5.0 μm. Further, the deviation Δ is 0.26 to 0.49 μm.

In embodiments 31 to 40, the collimating lens array and the collimating aperture array of the collimating film are both arranged in a regular triangle, the collimating lens layer (41) is made of PMMA, the flexible substrate layer (42) is made of PET, the light-shielding medium (43A) of the collimating aperture layer (43) is inorganic plated titanium carbide, the collimating film is perforated with collimating apertures (43B) by using a microlens perforation method, and other parameters are as follows:

p is 10-50 μm, R is 16-30.2 μm, H is 1.1-21.3 μm, and n1 is 1.5;

t is 50 μm, n2 is 1.65, D is 0.1-7.8 μm;

t is 0.5 μm and phi is 1.0-8.0 μm. Further, the deviation Δ is 0.21 to 0.88 μm.

In embodiments (41) to (47), the collimating lens array and the collimating aperture array of the collimating film are both arranged in a regular triangle, the collimating lens layer (41) is made of PMMA, the flexible substrate layer (42) is made of PET, the light-shielding medium (43A) of the collimating aperture layer (43) is inorganic plated titanium carbide, the collimating film is perforated by using a microlens to form collimating apertures (43B), and other parameters are as follows:

p is 30 μm, R is 19.3 μm, H is 10.8 μm, n1 is 1.5;

t is 38 μm, n2 is 1.65, D is 3.6 μm;

t is 0.5-7 μm and phi is 5.0-10.0 μm. Further, the deviation Δ is 0.46 to 0.99 μm.

In examples 48 to 57, the collimating lens array and the collimating hole array of the collimating film are both regularly triangular and closely arranged, the collimating lens layer (41) is made of PMMA, and further, is polymerized from a photo-curable acrylic resin, the refractive index n1 is adjustable from 1.4 to 1.6, when n2 is 1.65, the flexible substrate layer (42) is made of PET, when n2 is 1.5, the flexible substrate layer (42) is made of COP, the light-shielding medium (43A) of the collimating hole layer (43) is inorganic plated titanium carbide, the collimating film is perforated by microlenses to form collimating holes (43B), and other parameters are as follows:

p is 20-25 μm, R is 15.9-22.5 μm, H is 3.2-9.2 μm, n1 is 1.4-1.6;

t is 38-50 μm, n2 is 1.5-1.65, D is 0.5-3.6 μm;

t is 2.0 μm and phi is 4.0 μm. Further, the deviation Δ is 0.25 to 0.66 μm.

In example 58, the collimating lens array and the collimating aperture array of the collimating film are both arranged in a square shape (as shown in fig. 7), the collimating lens layer (41) is made of PMMA, the flexible substrate layer (42) is made of PET, the light-shielding medium (43A) of the collimating aperture layer (43) is inorganic plated titanium carbide, the collimating film is perforated with collimating apertures (43B) by using a microlens perforation method, and other parameters are as follows:

p is 25 μm, R is 19.6 μm, H is 11.1 μm, n1 is 1.5;

t is 38 μm, n2 is 1.65, D is 3.9 μm;

t is 2.0 μm and phi is 4.0 μm. Further, the deviation Δ was 0.69 μm.

The utility model discloses still provide the preparation method of collimation membrane, the collimation hole adopt the micro-focusing method to punch.

Furthermore, in the preparation method, laser is made to vertically irradiate the collimating lens layer, the laser is focused through the micro lens of the collimating lens layer, and a light spot formed by focusing falls on the collimating lens layer to form a collimating hole. In the preparation method, the distribution of the collimation hole array and the micro-lens array is completely consistent, and the circle center of any collimation hole is on the main optical axis of the corresponding micro-lens.

Further, the preparation method comprises the following steps:

(1) forming the collimating lens layer on the upper surface of the flexible substrate layer by adopting a lens array (concave) mould (light curing, heat curing, hot press forming and other modes can be adopted) to form a lens array (convex);

(2) coating/plating a shading medium on the lower surface of the substrate layer by adopting a wet method/dry method coating technology;

(3) the large-area flat-top laser (parallel laser after Gaussian beam shaping) is adopted, a micro-lens array is vertically irradiated with proper low energy, each micro-lens is focused on a shading medium (namely, a micro-focusing method) and corresponding collimating holes are punched, so that collimating hole arrays in the same distribution are generated, and a collimating hole layer is formed.

Further, the micro-focusing method comprises the following features:

(1) flat-top laser after beam shaping is adopted as a laser source, the irradiation area is enlarged after shaping, and the energy density is reduced;

(2) the front side is irradiated, the energy density is low, and the energy is concentrated through the micro-focusing process of the micro-lens per se, so that the high energy density is realized;

(3) the micro-focused light spot is small enough in a reasonable range, the focal point position needs to be designed on the lower surface of the PET or a deeper position, and energy is concentrated on the shading layer (shading medium);

(4) the micro-lens layer has high universality, and is applicable to irregular micro-lens layers, such as poor lens arrangement precision and shape precision, uneven spacing and even disorder.

Further, the process of the micro-focusing method (as shown in fig. 4) is divided into four basic steps: (a) flat-top laser (5) is applied to a collimating lens layer (41) of a collimating film semi-finished product with proper energy (too high hole is too large, even the hole is burnt to a substrate, too low, no hole is formed), micro focusing is realized by a micro lens (41A), pre-reduction of the area of a light spot is realized by a thick plate (41B), finally the laser penetrates through the substrate layer (42) and is focused into a very small light spot on a shading medium (43A), and high concentration of energy is realized; (b) due to the absorption of the light by the shading medium, the energy is instantaneously accumulated to cause the shading medium at the position of the light spot to be instantaneously burnt through and generate some ash, and actually, the process of the first two steps only needs microsecond level and is very quick; (c) after the ash is extracted, the alignment holes (43B) are exposed, and are originally arranged on the main optical axis (40) of the micro lens, so that the alignment holes are highly aligned with the micro lens (41A), and the time-consuming alignment process is avoided, at the moment, the alignment film (4) of the utility model is a finished product and comprises a complete structure, namely an alignment lens layer (41), a base layer (42) and an alignment hole layer (43); (d) the collimating film (4) meets the normal direction or is high in collimated light transmission close to the normal direction at the moment, a testing light source (such as white light, green light and a three-wave lamp) with common intensity can be used for irradiating from the surface of the micro-lens during online production, light can be transmitted out from the collimating hole, a light hole array image can be observed on the back surface, transmitted light intensity can be quantized, and therefore punching quality can be tested.

Compare the utility model provides a little focusing method punches, traditional mode of punching has great limitation (as shown in fig. 5): (a) the Gaussian laser (7) is focused through a lens group of the laser head and is shot on the shading medium (43A) from the back direction of the semi-finished product; (b) the different positions of the light shielding layer are sequentially burnt through, and some ash is generated; (c) as the ash is drawn away, the collimating holes are exposed. It can be seen that, in the whole alignment process, an original point O (or called Mark point) needs to be located, a CCD (Charge Coupled Device) high definition camera on the front side aligns the optical center of a lens, a laser head on the back side can be linked with the CCD camera on the front side to find the position of a corresponding alignment hole, so as to calculate the initial displacement (vector or coordinate difference) between the first point and the position, the initial positioning process is very time-consuming and complex, and the requirement on equipment is high; then, all the point positions can be calculated and positioned according to the initial displacement and the point displacement, 2-n points are sequentially punched, although the time can be shortened by using a vibrating mirror group in the process, n cannot be set too large, otherwise, the accumulated error inevitably exceeds 1 micrometer and is even larger, especially, the vibrating mirror can cause the angle inclination, the light spot becomes larger and deforms, and the error is accumulated more and more quickly; finally, when the error is unacceptably accumulated, the origin O is returned and the first point is found again, i.e. the initial positioning process is repeated. Throughout the whole process, although the time is shortened by adopting the galvanometer group, the n can not be too large, and the initial positioning process needs to be frequently carried out, so that the method is time-consuming, complex and dependent on equipment, and the punching process is high in cost and low in precision.

Further, the limitations of the conventional punching method are not limited to this: the process of locating the first point and calculating the 2-n points requires a precondition that the pitch of the microlenses is completely accurate; in fact, on one hand, the mold for the microlens is also prepared by laser drilling, and errors are inevitably generated, so that the alignment error of the traditional mode is further increased, especially when the mold precision is not so high; on the other hand, some special molds produce irregular microlens layers, which have poor arrangement precision and shape precision of the microlenses, or have non-uniform or even disordered designed spacing. Therefore traditional process, the mould precision and the preparation cost that have increased the microlens layer again become the looks, lead to whole collimation membrane cost very high, let alone realize that the counterpoint on irregular microlens layer punches (and the utility model discloses a micro-focusing method can easily realize).

It should be noted that the microlens array forming method should be selected according to the kind and application of the transparent polymer, and the present invention is not preferred; the coating mode of the shading medium is selected according to the type of the shading medium, the organic coating needs to be selected from a wet coating mode, and the inorganic coating needs to be selected from a dry coating (namely physical vapor deposition) mode.

It should be noted that the utility model provides a collimating film preparation method is applicable to the production of sheet, also is applicable to the production of coiled material.

The collimating film can be used as a flexible collimating device for an image sensor module. The collimating film can collimate and filter diffused light at a single-point pixel position of an image to a certain degree to form a normal small beam light signal, and transmits the normal small beam light signal to a corresponding photoelectric sensor, and is particularly suitable for large-size, ultrathin and even flexible image identification modules.

Compared with the prior art, the utility model provides a collimating film has adopted the polymer film that thickness is 10 ~ 50 mu m as flexible base member layer, has realized that the flexibility of collimating device, ultra-thin, jumbo size change, specially adapted jumbo size, ultra-thin, even in the flexible image recognition module.

Compared with the prior art, the utility model provides a collimation membrane adopts the micro-focusing method to punch, collimation hole array is unanimous completely with the distribution of microlens array, and the centre of a circle in each collimation hole is all on the primary optical axis of corresponding microlens, and a one-to-one high accuracy is aimed at, and the offset of counterpointing <1 mu m, not only improves the seeing through of signal light greatly, allows the collimation structure to further dwindle (dwindle like microlens and collimation hole synchronization) in order to reduce and crosstalk, has improved the SNR of collimation membrane, and improved production efficiency greatly, the cost is reduced.

Compared with the prior art, the utility model provides a collimation membrane only includes one deck collimation porose layer, has fundamentally solved the mutual difficult problem of counterpointing of two-layer collimation diaphragm, and, thickness is low, and toughness is good, not fragile, adopts the centre of a circle of the collimation hole that the preparation of micro-focus method obtained on the primary optical axis of corresponding microlens, collimation hole and corresponding microlens counterpoint accurately. The utility model provides a preparation method of collimation membrane easily operates, can produce in a large number, has improved the production yield. The utility model provides a collimation membrane's performance is excellent, can pass through collimated light, filters diffuse light. The utility model provides an among the collimation membrane can be applied to jumbo size, ultra-thin image recognition module, make jumbo size, ultra-thin, flexible image recognition module's volume production nature improves greatly even, when being applied to consumer electronics's such as cell-phone (OLED screen) fingerprint unblock scheme, very big because of its market demand, and have higher pursuit to characteristics such as ultra-thin, big screen, flexibility, the utility model discloses a collimation membrane advantage is obvious.

In addition, the orderly distributed collimating structure (which means that the microlens array of the collimating lens layer is orderly arranged) can meet the basic image recognition requirement in practical application, but there are interference fringes caused by too high regularity, as shown in fig. 11 a. Therefore, it is necessary to optimize the collimating structure to a disordered distribution, destroy regularity, and weaken interference fringes, as shown in fig. 11b, in order to further improve the image recognition accuracy (recognition rate).

The utility model provides a subtract microlens array on collimation lens layer of interference collimation membrane arranges for unordered, owing to adopted the micro-focus mode of punching for collimation hole array and the microlens array of collimation pore layer are identical completely, have not only kept the characteristics of unordered distribution, have still maintained the coaxial counterpoint of high accuracy, are that the tradition mode of punching can't realize all the time. Unordered microlens array collimation membrane can destroy the regularity of orderly microlens array, weakens because of the interference fringe that the regularity leads to (as shown in fig. 11 b), with further improvement the utility model provides an image identification rate of accuracy (recognition rate) of collimation membrane.

The collimating lens array and the collimating hole array of the disordered array collimating film (interference reducing collimating film) are disordered arrays, and the microlenses are closely arranged and overlapped with each other (as shown in fig. 12, the primary optical axis coordinates of any three mutually overlapped microlenses are connected into a common triangle (not a regular triangle, also called a non-regular triangle), in the interference reducing collimating film (disordered collimating film), the value range of P is 5-55 μm, the primary optical axis distance P of the two mutually overlapped microlenses changes in a disordered way within a certain value range, the variation of the adjacent primary optical axis distance P is A (the difference between the highest value and the lowest value in the value range of P), the median value of the adjacent primary optical axis distance P is Pm (the average value of the highest value and the lowest value in the value range of P), Pm-0.5A is not more than Pm and not more than Pm +0.5A, the median Pm is selected from 10-50 μm, preferably 15-30 μm, more preferably 18 to 25 μm, and the variation A of the main optical axis pitch P is selected from 1 to 10um, preferably 2 to 6 um.

Furthermore, in the interference reducing collimation film (disordered collimation film), the radius R of the micro lens is 6.1-30.2 μm, the height H of the collimation lens layer is 1.1-27.4 μm, and the refractive index n1 of the collimation lens layer material is 1.34-1.7; in the flexible substrate layer, the thickness T of the flexible substrate layer is 10-50 mu m, and the refractive index n2 of the flexible substrate layer material is 1.48-1.7; in the collimation hole layer, the thickness t of the collimation hole layer is 0.5-7 μm, and the diameter phi of collimation holes in the collimation hole array is 1-10 μm.

In the embodiments 81-86, the collimating lens array and the collimating hole array in the collimating film are disordered arrays, and the microlenses are closely arranged and overlapped with each other (as shown in fig. 12, the coordinates of the main optical axes of any three mutually overlapped microlenses are connected into a general triangle (not a regular triangle)). The distance P between the main optical axes of the two mutually overlapped micro lenses changes disorderly within a certain value range (Pm +/-0.5A). The collimating lens layer 41 is made of PMMA (polymethyl methacrylate), the flexible substrate layer 42 is made of PET (polyethylene terephthalate), the shading medium 43A of the collimating aperture layer 43 is inorganic plating titanium carbide, the collimating film adopts a micro-lens punching mode to punch out a collimating aperture 43B, and other parameters are as follows:

p is Pm plus or minus 0.5A, Pm is 30 μm, A is 1-10 μm, R is 20.6 μm, H is 27.4 μm, n1 is 1.5;

t is 25 μm, n2 is 1.65, D is 3.1 μm;

t is 2.0 μm and phi is 4.0 μm. Further, the deviation Δ was 0.81 μm.

In examples 87 to 92, the collimating film in which the collimating lens array and the collimating hole array are disordered arrays and the microlenses are closely arranged to overlap each other (as shown in fig. 12, the coordinates of the principal optical axes of any three mutually overlapping microlenses are connected to form a general triangle (not a regular triangle)). The distance P between the main optical axes of the two mutually overlapped microlenses changes disorderly within a certain value range (Pm ± 0.5A), wherein the median Pm and the variation a are listed in table 8. The collimating lens layer 41 is made of PMMA (polymethyl methacrylate), the flexible substrate layer 42 is made of PET (polyethylene terephthalate), the shading medium 43A of the collimating aperture layer 43 is inorganic plating titanium carbide, the collimating film adopts a micro-lens punching mode to punch out a collimating aperture 43B, and other parameters are as follows:

p is Pm plus or minus 0.5A, Pm is 18 μm, A is 1-10 μm, R is 14.8 μm, H is 16.3 μm, n1 is 1.5;

t is 25 μm, n2 is 1.65, D is 1.1 μm;

t is 2.0 μm and phi is 4.0 μm. Further, the deviation Δ was 0.41 μm.

Compared with the prior art, the utility model provides a subtract and interfere collimation membrane only includes one deck collimation porose layer, has solved the mutual difficult problem of counterpointing of two-layer collimation diaphragm fundamentally, and, thickness is low, and toughness is good, indelible, and the centre of a circle of the collimation hole that adopts the preparation of micro-focus method to obtain is accurate on the primary optical axis of corresponding microlens, collimation hole and corresponding microlens counterpoint. The utility model provides a subtract preparation method of interference collimation membrane easily operates, can produce in a large number, has improved the production yield. The utility model provides a subtract and interfere collimation membrane's performance is excellent, can pass through collimated light, filters the diffuse light, and light interference phenomenon alleviates. The utility model provides an it interferes collimation membrane to subtract can be applied to in jumbo size, ultra-thin image recognition module, makes jumbo size, ultra-thin, flexible image recognition module's volume production nature improves greatly even, when being applied to consumer electronics products's such as cell-phone (OLED screen) fingerprint unblock scheme, because of its market demand is very big, and has higher pursuit to characteristics such as ultra-thin, large screen, flexibility, the utility model discloses an it is obvious to subtract interference collimation membrane advantage.

Drawings

FIG. 1 is a schematic diagram of the basic principle of a collimating device;

FIG. 2 is a graph illustrating the effect of alignment accuracy of a collimated structure on signal strength; the higher the alignment precision is, the higher the signal intensity is;

FIG. 3 is a graph of the effect of the aspect ratio of the collimating structure on the crosstalk strength; the higher the length-diameter ratio, the smaller the crosstalk strength;

FIG. 4 illustrates a micro-focusing method of drilling;

FIG. 5 illustrates a conventional drilling alignment error accumulation process;

FIG. 6 is a schematic cross-sectional view of a collimating film provided by the present invention;

fig. 7 is a schematic perspective view (square arrangement) of the collimating film provided by the present invention;

fig. 8 is a schematic perspective view (regular triangle arrangement) of the collimating film provided by the present invention;

FIG. 9 is a schematic cross-sectional view of a collimating film (collimating sheet) provided in a comparative example;

fig. 10 is a light blocking performance (minimum light blocking angle) testing process of the collimating film provided by the present invention;

FIG. 11a shows interference fringes produced by an ordered collimating structure;

FIG. 11b shows interference fringes produced by a disordered collimating structure;

FIG. 12 is a top view of a collimating lens layer in a disordered distribution (to illustrate the meaning of the disordered distribution);

fig. 13 is a schematic perspective view of the interference reduction collimating film provided by the present invention (the microlens array is distributed in disorder).

Wherein:

1: target image

11-17: 7 continuous pixel points of target image

2: collimating device

21: top (incident light) collimation structure layer

22: bottom (light-emitting) collimation structure layer

3: photoelectric sensing chip

31-37: photoelectric sensor corresponding to 7 continuous pixel points

4: the utility model provides a collimation membrane

4': comparative example provided collimating film

40: middle axis of collimation structure (micro lens main optical axis)

41: collimating lens layer

41A: microlens array

41B: thickness of meat

41C: apex of microlens

42: substrate layer

43: collimating aperture layer

43A: light-screening medium

43B: collimation hole

5: flat-top beam laser

6: inspection light source

7: gaussian beam laser

O: laser positioning origin

Detailed Description

In order to make the structure and features of the present invention easier to understand, preferred embodiments of the present invention will be described in detail below with reference to the drawings.

Comparative example 1

FIG. 9 shows a collimating film for comparison, which includes a collimating lens layer 41, a flexible substrate layer (substrate for short) 42, and collimating holesA layer 43, a collimating lens layer disposed on the upper surface of the substrate, a collimating hole layer disposed on the lower surface of the substrate, the collimating lens layer 41 comprising a micro lens array 41A and a thick 41B, the collimating hole layer 43 comprising a light-shielding medium 43A and a collimating hole array (composed of a certain number of collimating holes 43B) formed by hollowing out the medium; the thickness T of the flexible substrate layer is 25 mu m. The collimating lens array and the collimating hole array of the collimating film are both in regular triangle close arrangement (as shown in fig. 8). The minimum distance P of the main optical axis of the micro lens is 18 mu m, the curvature radius R is 12.6 mu m, the thickness H of the collimating lens layer (the vertical distance from the top point of the micro lens to the upper surface of the substrate) is 8.5 mu m, the thickness t of the collimating hole layer is 2 mu m, and the diameter phi of the collimating hole is 4 mu m. The micro-lens array and the thick material of the collimating lens layer are both transparent polymer PMMA, the refractive index n1 is 1.5, the flexible substrate layer is made of transparent polymer film PET, the refractive index n2 is 1.65, and the shading medium 43A of the collimating lens layer 43 is inorganic coating titanium carbide. The collimating film is punched with collimating holes 43B by conventional laser punching (as shown in FIG. 5), the central positions of the main optical axis 40 and the collimating holes 43B have alignment deviation, and holes are punched one by one from the laser positioning origin O, and the alignment deviation of the first hole is Δ₁The misalignment of the nth hole is Δ_n，Δ_n-1<Δ_n(n is a natural number greater than 2), the presence of n makes the misalignment Δ exceed 1 μm or even greater. The light transmission coefficient k is easily reduced, even to less than 0.6, and reaches the evaluation level of "poor".

Example 1

The utility model provides a collimating film as shown in fig. 6, including collimating lens layer 41, flexible base member layer 42 and collimation hole layer 43, the collimating lens layer is arranged in the upper surface of base member, and the collimation hole layer is arranged in the lower surface of base member, collimating lens layer 41 contains microlens array 41A and fleshy 41B, collimation hole layer 43 contains shading medium 43A and the collimation hole array (by a certain amount of collimation hole 43B constitution) that the medium fretwork formed back; the thickness T of the flexible substrate layer is 25 mu m. The collimating lens array and the collimating hole array of the collimating film are both in regular triangle close arrangement (as shown in fig. 8). The micro-lens has a minimum distance P of a main optical axis of 18 μm, a curvature radius R of 12.6 μm, a thickness H of a collimating lens layer of 8.5 μm, a thickness t of a collimating hole layer of 2 μm, and a diameter phi of a collimating hole of 4 μm. The micro-lens array and the thick material of the collimating lens layer are both transparent polymer PMMA, the refractive index n1 is 1.5, the flexible substrate layer is made of transparent polymer film PET, the refractive index n2 is 1.65, and the shading medium 43A of the collimating lens layer is inorganic coating titanium carbide. The collimating film adopts a micro-focusing method punching mode (as shown in fig. 4) to punch a collimating hole 43B, the collimating hole array is completely consistent with the distribution of the micro-lens array, the circle centers of any collimating hole are all on the main optical axis 40 of the corresponding micro-lens, the collimating hole array and the micro-lens array are aligned in a one-to-one high-precision mode, and the alignment deviation delta between the circle centers of the collimating holes and the main optical axis of the corresponding micro-lens is 0.47 mu m and less than 1 mu m. When punching, the laser is just slightly focused on the lower surface of PET, the diameter D of a light spot is 1.7 mu m, the minimum light blocking angle theta is 7.5 degrees, the light transmission coefficient k is 0.98, and the performance advantage of the laser is obvious compared with that of comparative example 1 on the whole.

In fact, the combination of the structural parameters of the collimating lens is not limited to the above embodiments: for the same collimating and filtering effect, various changes can be made according to the material and refractive index of the collimating lens layer, the material and refractive index of the flexible substrate layer, for example, P, R, H, phi, t, etc. are changed correspondingly; aiming at the light shielding effect of the collimating holes with the same thickness t, various changes can be made to the light shielding medium, such as changes of the types, combinations and even proportions of organic coatings and inorganic coatings.

The performance of the collimating film provided by the present invention was evaluated in the following manner.

(A) Light blocking Property

The final important performance index of a collimating film is the ability to block stray light, and is generally evaluated by the minimum angle at which oblique light can be blocked. When various parameters of the collimating film are determined, the minimum angle θ capable of completely blocking oblique Light can be obtained through conventional optical simulation software (Light tools, ZeMax, Tracepro, etc.) or theoretical calculation. As the minimum angle test process of collimating film shown in fig. 10, the utility model discloses according to the size of theta (accurate to 0.5 degree), will be in the light performance and carried out the division of 5 grades, correspond the relation in proper order and be: excellent: theta is more than or equal to 0 degree and less than 5 degrees, and is superior: theta is more than or equal to 5 degrees and less than 7.5 degrees, good: theta is more than or equal to 7.5 degrees and less than 10 degrees, wherein: theta is more than or equal to 10 degrees and less than 15 degrees, difference: theta is more than or equal to 15 degrees.

(B) Light transmission performance

Another important performance criterion of collimating films is the ability to transmit signal light. The alignment precision between the collimating hole and the micro-lens can be checked by using a vertical collimating light source for incidence: when the alignment degree is high enough, the light spot is always in the diameter range of the collimation hole, the light transmittance is the best, and the transmittance is the maximum (obtained by testing a standard sample under the high-precision condition of an optical simulation or a laser head, generally about 90 percent); when the alignment error increases, the transmittance will be attenuated continuously; since the number of collimating holes is very large, the degree of alignment can be compared by measuring the transmittance change under macroscopic conditions in this manner. The utility model discloses the transmittance that will test the gained and the light transmittance that the ratio definition of the highest transmittance (the highest transmittance refers to the main optical axis of microlens and the light transmittance that surveys under the condition of the central line coincidence completely of the collimation hole that corresponds) is light transmittance k, is 1 when the degree of alignment is enough high. The utility model discloses according to the size of k, carried out the division of 5 grades with light transmission performance, the correspondence is in proper order: excellent: k is more than or equal to 1 and more than 0.95, preferably: 0.95 is more than or equal to k is more than 0.9, good: 0.9 is more than or equal to k is more than 0.8, wherein: 0.8 is more than or equal to k is more than 0.6, the difference is: k is less than or equal to 0.6.

Obviously, both of the above properties are crucial for the collimating film: the larger k, the stronger the signal; the smaller θ, the less noise; both parameters are of great help to enhance the image recognition signal-to-noise ratio (SNR).

Examples 2 to 24

In the collimating film provided in embodiment 1, the collimating lens arrays and the collimating hole arrays in the collimating film are both arranged in a regular triangle, the collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the light-shielding medium 43A of the collimating hole layer 43 is inorganic plated titanium carbide, the collimating film is perforated with the collimating holes 43B by using a microlens perforation method, and the other parameters are listed in table 1.

TABLE 1 design parameters and optical Properties of examples 1-24

Note 1: p is the minimum distance of the main optical axis of the micro lens and is in the unit of mum; r is the curvature radius of the micro lens and the unit is mum; h is the thickness of the collimating lens layer in μm; n1 is the refractive index of the collimating lens layer, dimensionless; t is the thickness of the flexible substrate layer and the unit of micrometer; n2 is the refractive index of the flexible matrix layer, dimensionless units; d is the diameter of a light spot formed on the lower surface of the flexible substrate layer after being focused by the micro lens, and the unit of the diameter is mum; t is the thickness of the collimation bore layer, unit μm; phi is the diameter of the collimating hole and the unit is mum; theta is the minimum oblique light angle which can be filtered by the collimating film and is used for measuring the collimating and filtering effect in unit degree; k is the ratio of the actual transmittance to the highest transmittance of the collimating film, and is used for measuring the alignment precision of the collimating holes and the micro lenses.

As shown in table 1, relatively good examples were designed for different P values on a flexible substrate layer of 25 μm thickness. When the P values are 10, 15, 18, 20, 25 and 30 μm, respectively, four examples correspond to each other. It can be found that when the P value and other conditions are not changed, and the R value is increased, the lens becomes shallow (the height of the thick lens layer is increased, and the height of the lens arch, i.e. the height from the top point of the lens to the upper surface of the thick lens layer, becomes smaller), the focal length becomes farther, and the light spot of the micro-focus on the light shielding layer becomes larger, so that the focal point returns to the light shielding layer by matching with the increase of H, the light spot is reduced, and the matching change of R, H can continuously reduce the diameter D of the micro-focus light spot, gradually reduce the minimum light blocking angle theta, and improve the light blocking performance. For the light transmission performance, the more the spot diameter D is close to the opening (collimating hole) diameter phi, the more the alignment deviation Δ has an influence on the light transmission, and a slight deviation, the loss of the signal light is generated, while the smaller D is, the less the influence on the alignment deviation is, and the light is still in the hole regardless of the direction of movement. The utility model provides an embodiment 1-24 all fix trompil diameter phi and be 4 mu m, except that D and phi are more close in embodiment 21 ~ 23, other embodiments all keep certain difference, and the coefficient of light transmittance k is greater than 0.9. In general, most of examples 1 to 24 can achieve the level of more than two excellent light blocking performance and light transmission performance, and are based on the excellent implementation effect of a flexible substrate with the thickness of 25 μm.

Examples 25 to 30

In the collimating film provided in embodiment 1, the collimating lens array and the collimating aperture array in the collimating film are both closely arranged in a regular triangle, the collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the light-shielding medium 43A of the collimating aperture layer 43 is inorganic plated titanium carbide, the collimating film is perforated with the collimating apertures 43B by using a microlens perforation method, and the other parameters are listed in table 2.

TABLE 2 design parameters and optical Properties of examples 25-30

Note 1 is as in Table 1.

As shown in Table 2, examples 25 to 30 are examples of different thicknesses of the flexible substrate. Examples 25 to 27 each represent a set of collimation films with P of 10 μm, 15 μm and 20 μm, and examples 28 to 30 each represent a set of collimation films with P of 25 μm, and with T of 25 μm, 38 μm and 50 μm, respectively, under the condition that the other parameters are not changed. When T is continuously increased, in order to maintain the micro-focusing effect (the focus is always located near the lower surface of the substrate and the light shielding layer and the light spot is minimized), the micro-lens structure obviously needs to be shallow, i.e. the R value is increased and H is lowered under the condition of fixing the P value and the refractive index collocation (compared with the difference of the embodiment in table 1, the focal length design is adapted along with the increase of T, so H does not need to be increased but is lowered). It can be found that, when other conditions are unchanged, the thickness T is increased, which is beneficial to the structure becoming shallow, the light spot D is reduced, the minimum light-blocking angle θ is reduced, the light-blocking performance is improved, and the light-transmitting coefficient is further improved. Therefore, in the range of thickness allowed (ultra-thin applications are more and more common, and too thick is not allowed), the performance improvement of the alignment film is helpful by using a relatively thick substrate, and the principle that the alignment film with a large length-diameter ratio has better performance (such as the principle shown in fig. 3) is met. In summary, in the present invention, T is selected from 10 to 50 μm, and more preferably 25 to 38 μm.

Examples 31 to 40

As in the collimating film provided in embodiment 1, the collimating lens array and the collimating aperture array of the collimating film are both arranged in a regular triangle, the collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the light-shielding medium 43A of the collimating aperture layer 43 is inorganic plated titanium carbide, the collimating film is perforated with the collimating apertures 43B by using a microlens perforation method, and the other parameters are listed in table 3.

TABLE 3 design parameters and optical Properties of examples 31-40

Note 1 is as in Table 1.

As shown in Table 3, it can be seen from the comparative examples 31 to 36 that the R value becomes large when the P value is increased without changing other conditions, and the focal length becomes far and H becomes large according to the similar principle if the original aspect ratio is maintained. Even if the focal length can be controlled, the spot radii D and θ cannot be prevented from increasing, and k is therefore decreased for the same aperture diameter. Therefore, in general, the larger P value is not favorable for the performance of the collimating film, which also conforms to the principle that the collimating film with a large length-diameter ratio has better performance (as shown in FIG. 3). In addition, in comparative examples 37 and 33, 38 and 34, 39 and 35, when the spot D is sufficiently small, the diameter of the hole Φ can be reduced by adjusting the laser energy, and is not necessarily limited to a fixed value, and it can be found that the light blocking performance can be further improved after the diameter of the hole is reduced, but the light transmission effect is reduced. Example 40 has a P value of 50 μm, and the corresponding R and H are both large, and overall for the collimating film of the present invention, the microlens size has reached the upper design limit, including that the spot diameter D is also large (D is particularly small, especially less than 0.5 μm is not good, and it is easy to cause a single point energy too high, burn substrate) resulting in an opening diameter phi of up to 8 μm, while the minimum light blocking angle theta is 12 degrees and is also large, and the light blocking performance is not very good. In summary, in the present invention, P is selected from 10 to 50 μm, preferably 15 to 30 μm, and more preferably 18 to 25 μm. Phi is selected from 1 to 10 μm (10 μm from example 47), and more preferably 3 to 5 μm. D is selected from 0.1 to 7.8 μm, preferably 0.5 to 4.9 μm, and more preferably 1 to 2 μm.

Examples 41 to 47

As in the collimating film provided in embodiment 1, the collimating lens array and the collimating aperture array of the collimating film are both arranged in a regular triangle, the collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the light-shielding medium 43A of the collimating aperture layer 43 is inorganic plated titanium carbide, the collimating film is perforated with the collimating apertures 43B by using a microlens perforation method, and the other parameters are listed in table 4.

TABLE 4 design parameters and optical Properties of examples 41-47

Note 1 is as in Table 1.

As shown in Table 4, examples 41 to 47 are examples with different thicknesses t of the collimation holes. As can be seen from comparison of the first group of examples 41 to 44 and comparison of the second group of examples 45 to 47, when other conditions are not changed, increasing t contributes to improvement of light blocking performance, and t is too thin and is not a preferable value. Since laser drilling typically forms holes with smaller aspect ratios, the hole diameter tends to be larger than t, and thus when t is too thick, the hole diameter is actually too large (as in the second group of embodiments), which in turn gradually reduces the light blocking performance. The utility model discloses well t is selected from 0.5 ~ 7 mu m, preferably 1 ~ 5 mu m, and further preferably 2 ~ 3 mu m.

Examples 48 to 57

The collimating film provided in embodiment 1, wherein the collimating lens array and the collimating hole array of the collimating film are both regularly triangular and closely arranged, the collimating lens layer 41 is made of PMMA, and further made of a photo-curable acrylic resin, the refractive index n1 is adjustable from 1.4 to 1.6, when n2 is 1.65, the flexible substrate layer 42 is made of PET, when n2 is 1.5, the flexible substrate layer 42 is made of COP, the light-shielding medium 43A of the collimating hole layer 43 is inorganic coated titanium carbide, the collimating film is perforated by microlenses to form collimating holes 43B, and the other parameters are listed in table 5.

TABLE 5 design parameters and optical Properties of examples 48-57

Note 1 is as in Table 1.

As shown in Table 5, examples 48-57 with different refractive index combinations are provided. As can be seen by comparing the first set of examples 48-52, under otherwise unchanged conditions: 1. increasing n1 (comparative examples 50, 48, 49 or comparative examples 51, 52) helps to reduce the flare D, lower θ and improve light blocking performance, with n1 being the best at 1.6 and n1 being the worst at 1.4; 2. the reduction in n2 (comparison of examples 51, 52 with examples 48, 49) was equally effective. The law of the influence of the refractive index remains the same in comparison with the second group of examples 53 to 57, but the influence is not so great because the second group has a shallow structure and the performance is originally excellent enough. For n1, the choice of molding material with too high or too low refractive index is narrower, while for n2, the physical properties of the flexible substrate itself and the light transmittance are considered more, and the refractive index is used only for the precise design of the structure. Therefore, in the present invention, n1 is selected from 1.4 to 1.6, preferably 1.5. n2 is selected from 1.5-1.65, which is not preferred according to the material difference.

Example 58

As in the collimating film provided in embodiment 48, the collimating lens array and the collimating aperture array of the collimating film are both arranged in a square shape (as shown in fig. 7), the collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the light-shielding medium 43A of the collimating aperture layer 43 is inorganic plated titanium carbide, the collimating film is perforated with the collimating apertures 43B by using a microlens perforation method, and the other parameters are listed in table 6.

TABLE 6 design parameters and optical Properties of examples 48, 58

Note 1 is as in Table 1.

As can be seen from table 6, when other parameters are not changed, the distribution of the microlenses is changed from regular triangles to squares, and a collimating film can still be obtained by the matching design of R, H. But the performance of the collimating film is slightly inferior to the regular triangular distribution. The main reason is that the squares are not dense like regular triangles in distribution, and the squares are larger in ratio between the diagonal lines and P, so that the spherical crowns arranged in the squares are more convex with the same P value, so that light spots are more scattered, D is larger, and theta is increased, the light blocking effect is poor, and the light transmittance is poor due to the fact that D is enlarged. Of course, square arrangement is not undesirable, and a smaller P value needs to be designed to achieve the same effect. The utility model discloses no longer give unnecessary details the embodiment that more squares distribute, the square distributes all the time the utility model discloses a within the protection scope.

Examples 59 to 80

The collimating film provided in embodiments 53 to 57, wherein the collimating lens array and the collimating aperture array of the collimating film are both closely arranged in a regular triangle, the minimum pitch P of the main optical axes of the microlenses of the collimating lens layer is 20 μm, the radius of curvature R is 18.3 μm, the total thickness of the collimating lens layer is 4.1 μm, the thickness of the flexible substrate layer is 50 μm, the thickness of the collimating aperture layer is 2 μm, the diameter of the collimating aperture is 4 μm, the collimating film is formed by punching the microlenses to form the collimating apertures 43B, and the alignment errors Δ between the microlenses and the collimating apertures are less than 1 μm. The light blocking angles theta are all smaller than 5 degrees, the light blocking performance is excellent, the light transmission coefficients k are all larger 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 collimating hole layer shading medium are listed in table 7, the refractive index n1 of the collimating lens layer and the refractive index n2 of the flexible base layer are different according to the materials, and errors caused by different processes of +/-0.02 same materials are allowed, and are not listed in the table.

TABLE 7 design parameters and optical Properties of examples 59-80

Note 1 is as in Table 1.

Note 2: for the same material of the collimating lens layer, the molding method is not limited to photocuring, thermocuring, injection molding, hot pressing, etc.

As shown in Table 7, it is understood that the performance of the alignment film is not greatly affected by the same or close refractive index of the material before and after changing the material in comparative examples 59 to 80.

Examples 81 to 86

A collimating film as provided in example 24, having a cross-section as shown in fig. 6 and a perspective view as shown in fig. 13. The collimating lens array and the collimating hole array in the collimating film are disordered arrays, and the microlenses are closely arranged and overlapped with each other (as shown in fig. 12, the coordinates of the main optical axes of any three mutually overlapped microlenses are connected into a common triangle (not a regular triangle)). The distance P between the main optical axes of the two mutually overlapped microlenses changes disorderly within a certain value range (Pm ± 0.5A), wherein the median Pm and the variation a are listed in table 8. The collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the light-shielding medium 43A of the collimating aperture layer 43 is inorganic plating titanium carbide, the collimating film is perforated by a microlens to form collimating apertures 43B, and the other parameters are listed in table 8.

TABLE 8 design parameters and optical Properties of examples 24 and examples 81-86

Note 1: p is the distance between the main optical axes of the two mutually overlapped micro lenses, and the value range of P is Pm +/-0.5A and the unit of mum; pm is the average value of the maximum value and the minimum value in the value range of P, called the median, A is the difference between the maximum value and the minimum value in the value range of P, called the variation, unit mum; r is the curvature radius of the micro lens and the unit is mum; h is the thickness (or called height) of the collimating lens layer in μm; n1 is the refractive index of the collimating lens layer, dimensionless; t is the thickness of the flexible substrate layer and the unit of micrometer; n2 is the refractive index of the flexible matrix layer, dimensionless units; d is the diameter of a light spot formed on the lower surface of the flexible substrate layer after being focused by the micro lens, and the unit of the diameter is mum; t is the thickness of the collimation bore layer, unit μm; phi is the diameter of the collimating hole and the unit is mum; theta is the minimum oblique light angle which can be filtered by the collimating film and is used for measuring the collimating and filtering effect in unit degree; k is the ratio of the actual transmittance to the highest transmittance of the collimating film for measuring the alignment accuracy of the collimating holes and the microlenses

Note 2: the collimating lens array and the collimating aperture array of example 24 are both in regular triangular close arrangement; the collimating lens arrays and the collimating hole arrays of embodiments 81-86 are disordered arrays and closely arranged;

as can be seen from table 8, when the other parameters were not changed, the alignment film changed from a fixed P value to a P value that varied randomly, and the performance was not substantially affected. The A value is a variable selected from 1 to 10 μm, preferably 2 to 6 μm. When a is too small, the interference reduction effect is not significant, and when a is too large, the array morphology becomes poorly controlled, reproducibility is poor, and there are many light leakage regions that occur due to too far a distance.

Examples 87 to 92

A collimating film as provided in example 4 has a cross-section as shown in fig. 6 and a perspective view as shown in fig. 13. The collimating lens array and the collimating hole array in the collimating film are disordered arrays, and the microlenses are closely arranged and overlapped with each other (as shown in fig. 12, the coordinates of the main optical axes of any three mutually overlapped microlenses are connected into a common triangle (not a regular triangle)). The distance P between the principal optical axes of the two mutually overlapped microlenses varies disorderly within a certain value range (Pm ± 0.5A), wherein the median Pm and the variation a are listed in table 9. The collimating lens layer 41 is made of PMMA, the flexible substrate layer 42 is made of PET, the shading medium 43A of the collimating aperture layer 43 is inorganic plating titanium carbide, the collimating film is provided with collimating apertures 43B by adopting a micro-lens punching mode, and other parameters are listed in Table 9.

TABLE 9 design parameters and optical Properties of examples 4 and 87-92

Note 1 is as in Table 8;

note 2: the collimating lens array and the collimating aperture array of embodiment 4 are both in regular triangle close arrangement; the collimating lens array and the collimating aperture array of embodiments 87-92 are both disordered arrays and closely arranged;

as can be seen from Table 9, when the other parameters were not changed, the P value of the collimating film changed from a constant P value of 18 μm to a disordered P value (in the narrowest range of 17.5 to 18.5 μm, and in the widest range of 13 to 23 μm), and the performance was not substantially affected. The A value is a variable selected from 1 to 10 μm, preferably 2 to 6 μm. When a is too small, the interference reduction effect is not significant, and when a is too large, the array morphology becomes poorly controlled, reproducibility is poor, and there are many light leakage regions that occur due to too far a distance.

It should be understood that any one of the ordered collimating films of the present invention can have the P value randomly changed to some extent to obtain a new disordered collimating film, and therefore, the Pm value in the disordered collimating film and the P value in the ordered collimating film are both selected from 10 to 50 μm, preferably 15 to 30 μm, and further preferably 18 to 25 μm. The utility model discloses only carry out unordered optimization with embodiment 24 and embodiment 4, no longer enumerate more embodiments and describe repeatedly, nevertheless this does not influence the utility model provides a patent range of unordered collimation membrane.

It should be noted that the above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. All equivalent changes and modifications made according to the present invention are covered by the scope of the present invention.

Claims

1. The interference reduction collimation film is characterized by comprising a collimation lens layer, a flexible substrate layer and a collimation hole layer in sequence; the collimating lens layer comprises a micro-lens array and a thickness; the collimation hole layer comprises a shading medium layer and a collimation hole array; the distribution of the collimation hole array is completely consistent with that of the micro-lens array, and each collimation hole is arranged on the main optical axis of the corresponding micro-lens; the micro-lens array of the collimating lens layer is arranged in disorder.

2. The subtractive interference collimating film according to claim 1, wherein the microlenses in the microlens array are closely spaced.

3. The interference reducing collimating film of claim 1, wherein the coordinates of the principal optical axes of adjacent three microlenses in the microlens array of the collimating lens layer are connected to form a non-regular triangle.

4. The interference reduction collimation film as claimed in claim 1, wherein in the collimation lens layer, the pitch P of the main optical axes of the adjacent microlenses is 5-55 μm, the variation of the pitch P of the main optical axes of the adjacent microlenses is A, the median value of the pitch P of the main optical axes is Pm, and then Pm-0.5A is not less than P is not less than Pm + 0.5A; the Pm is 10-50 mu m, and the variation A of the main optical axis distance P is 1-10 mu m; the radius R of the micro lens is 6.1-30.2 μm, the height H of the collimating lens layer is 1.1-27.4 μm, and the refractive index n1 of the collimating lens layer material is 1.34-1.7;

in the flexible substrate layer, the thickness T of the flexible substrate layer is 10-50 mu m, and the refractive index n2 of the flexible substrate layer material is 1.48-1.7;

in the collimation hole layer, the thickness t of the collimation hole layer is 0.5-7 μm, and the diameter phi of collimation holes in the collimation hole array is 1-10 μm.

5. The interference reduction collimation film as recited in claim 4, wherein the variation A of the main optical axis pitch P is 2-6 um.

6. The interference reducing collimation film of claim 4, wherein the Pm is 15-30 μm.