CN116953829A

CN116953829A - Oblique-crossing composite light homogenizing film and preparation method thereof

Info

Publication number: CN116953829A
Application number: CN202210390946.8A
Authority: CN
Inventors: 李刚; 夏寅; 张灿; 叶志鹏; 陈建文; 唐海江; 张彦
Original assignee: Ningbo Exciton Technology Co Ltd
Current assignee: Ningbo Exciton Technology Co Ltd
Priority date: 2022-04-14
Filing date: 2022-04-14
Publication date: 2023-10-27

Abstract

The invention relates to an optical film, in particular to an oblique-crossing composite dodging film and a preparation method thereof. In order to weaken LED lamp shadow and improve uniformity, the invention provides an oblique-crossing composite light homogenizing film and a preparation method thereof. The oblique-crossing composite light-homogenizing film comprises a light-filtering matrix layer, a composite adhesive layer, a light-splitting layer, a matrix layer and a light-expanding layer from bottom to top, wherein the light-splitting layer is positioned on the lower surface of the matrix layer, the composite adhesive layer is positioned on the upper surface of the light-filtering matrix layer, and the tip of the light-splitting layer is combined with the composite adhesive layer; the light splitting layer comprises N long ribs in N directions, and N is 2; the light-expanding layer is an oblique prism layer, the oblique prism layer comprises a plurality of triangular prism ribs, and the extending direction omega of the triangular prism ribs ₄ The extending direction of the long rib of the light splitting layer is omega ₁ And omega ₂ The collocation angle delta omega = omega of the triangular prism rib and the long rib direction ₄ ‑ω ₁ Delta omega is 30-60 degrees. The oblique-crossing composite light homogenizing film provided by the invention can weaken the LED lamp shadow and improve the uniformity.

Description

Oblique-crossing composite light homogenizing film and preparation method thereof

Technical Field

The invention relates to an optical film, in particular to an oblique-crossing composite light homogenizing film for weakening LED lamp shadows and improving uniformity and a preparation method thereof.

Background

Light Emitting Diodes (LEDs) are the most commonly used light sources in the field of optoelectronic displays, and how to efficiently and uniformly convert such point light sources into the desired linear light sources or even surface light sources has been the subject of continuous research.

In the conventional Liquid Crystal Display (LCD) field, a backlight module is required to provide a light source for the LCD, especially a direct type backlight module, and an LED array emits light with a certain beam angle vertically upwards from a lamp panel, and converts a point light source into a uniform surface light source through a diffusion plate and various conventional optical films (such as a diffusion film and a brightness enhancement film).

Because most of the light emitted by the LED is concentrated in the beam center and the beam angle deviating from the center by a small range, the highly concentrated light can generate higher light intensity (the peak light intensity of the cosine illuminant is in the beam center, the light intensity of other angles is gradually attenuated, the ratio of the peak light intensity to the light intensity is equal to the cosine value of the angle), small and bright light spots (Hotspot) can be formed right above the position of the lamp when the light is projected onto the panel, and the energy (illumination) distribution fall between the center of the light spot and the two light spots is large, so that the problem of uneven light shadow or light emission is generated.

Particularly, in some new display technology application scenarios, when the brightness of the LED single lamp is higher, the distance between the lamps is larger, or the light mixing distance is shorter, the drop of the energy distribution is further increased, and the lamp shadow phenomenon becomes more obvious. For example, in order to pursue the limit of visual effect, the MiniLED model designs the brightness of a single lamp to be high, thereby improving the contrast and the peak brightness, designs the mixed light distance (OD) to be short to reduce the halation phenomenon of a dark field, so as to reduce the crosstalk between pixels, and has higher difficulty in lamp shadow resolution; for another example, in order to thin the large-size common direct type machine, the OD needs to be shortened, or in order to reduce the lamp consumption, the lamp distance needs to be enlarged, and the difficulty of lamp shadow removal is also high.

How to reasonably distribute the energy concentrated in a certain range of the center of the point light source beam to other directions under a shorter light mixing distance, and reduce the energy of a central bright spot on a projection screen (middle finger panel position of an LCD) and enlarge the whole light emitting area, thereby improving the uniformity of energy distribution (reducing standard deviation), and being key to solving the problem of lamp shadow.

However, the conventional diffusion plate and diffusion film only use the refraction, scattering and reflection of particles (whether air bubbles, organic particles, inorganic particles or particle-free imprinting) to perform the disordered diffusion (nondirectional) of light, so that the light emitting area is limited to expand, and the energy is still concentrated at the central position, thus failing to satisfy the light homogenizing effect of the application scene (as shown in fig. 1a and 1 b).

Therefore, there is a need to develop a light homogenizing film (as shown in fig. 1a and 1 c) that has a directional adjustment of the light direction, effectively separates (splits) the light concentrated in the center, and can expand the light emitting area (expands the light effect).

Disclosure of Invention

In order to solve the problem of lamp shadow of a point light source array with high brightness and short OD, the invention provides a dodging film and a preparation method thereof.

The dodging film provided by the invention can reasonably distribute the energy concentrated in a certain range of the beam center of the point light source to other directions, and can reduce the energy of the central bright spot on the projection screen and enlarge the whole luminous area, thereby improving the uniformity of energy distribution. The light homogenizing film provided by the invention can make the emitted light more uniform, the brightness more uniform, and the lamp shadow problem of the point light source array with high brightness and short OD can be improved.

In order to solve the technical problems, the invention adopts the following technical scheme:

the invention provides a light homogenizing film, which comprises a light splitting layer and a matrix layer.

The invention provides a light homogenizing film which comprises a light splitting layer, a substrate layer and a light expanding layer, wherein the light expanding layer is positioned on the upper surface of the substrate layer, and the light splitting layer is positioned on the lower surface of the substrate layer.

The line roughness Ra of the surface of the light splitting layer is less than 250nm. The surface smoothness of the light splitting layer is high.

The light homogenizing film can reasonably distribute the energy concentrated in the central beam angle of the point light source beam to other directions, and reduce the energy of the central bright spot on the projection screen and enlarge the whole luminous area, so that the uniformity of energy distribution is improved by at least 30%.

Further, when the light part of the light source within 30 degrees of the beam angle passes through the dodging film, a single bright point can be observed on the projection screen to be converted into a plurality of bright points or the superposition of the plurality of bright points, the size of the bright point is reduced, the intensity is weakened, the uniformity of the energy distribution is measured by adopting the standard deviation of the illuminance distribution on the projection screen, and the standard deviation of the illuminance distribution can be improved by at least 30%.

The light splitting layer is formed by overlapping long ribs in N directions, N is a topological coefficient, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, the N directions equally divide 360 degrees of azimuth angles, namely the angle intervals between the adjacent directions are 180/N degrees, and N is selected from 1, 2 or 3.

The long ribs in the light splitting layer have the same cross section and are isosceles triangles, the left waist and the right waist are one of straight lines, convex arcs or concave arcs which are cut off at two ends in a limited way, the bottom edge is a straight line, and the bottom edge W ₁ 10-100 mu m, and the vertex angle theta is 60-120 degrees; the bending degree of the convex arc line or the concave arc line (called concave-convex arc line for short) is represented by a central angle, and the central angle alpha is 1-30 degrees.

The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer and a concave cambered surface light splitting layer, and the left waist and the right waist of the isosceles triangle with the corresponding long rib cross section are respectively a straight line, a convex arc line (called convex arc line for short) and a concave arc line (called concave arc line for short) which are cut at two ends in a limited way.

The substrate layer is made of transparent polymer, and the material is selected from one of polyethylene terephthalate (PET), methyl methacrylate (PMMA), polycarbonate (PC), cellulose Triacetate (TAC) and cycloolefin polymer (COP).

The thickness M of the substrate layer is 25-500 mu M.

The light homogenizing film is one of a plane light homogenizing film, a prism light homogenizing film, a cylindrical lens light homogenizing film, a pyramid light homogenizing film or a micro lens light homogenizing film.

The light homogenizing film is a plane light homogenizing film, and the plane light homogenizing film comprises a light splitting layer and a matrix layer. The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer. The beam splitting layer with the isosceles triangle waist of the cross section of the long rib being a straight line is called a standard surface beam splitting layer, the beam splitting layer with the waist being an outward convex arc is called a convex arc beam splitting layer, and the beam splitting layer with the waist being an inward concave arc is called a concave arc beam splitting layer.

The light homogenizing film is a prism light homogenizing film, and the prism light homogenizing film comprises a light splitting layer, a matrix layer and a light expanding layer. The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer. The light-expanding layer is a prism layer and is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom side V of the triangle is 10-100 mu m, and the vertex angle beta is 60-120 degrees. Further, the apex angle beta is 75-105 degrees.

The dodging film is a cylindrical dodging film, and the cylindrical dodging film comprises a light splitting layer, a matrix layer and a light expansion layer. The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer. The light expansion layer is a cylindrical lens layer and is formed by tiling a cylindrical lens, the cross section of the cylindrical lens is an arc, the width (chord length) F of the arc is 20-1000 mu m, the height of the arc is K, and the height-width ratio K/F is 0.05-0.5.

The light homogenizing film is a pyramid light homogenizing film, and the pyramid light homogenizing film comprises a light splitting layer, a matrix layer and a light expanding layer. The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer. The light expansion layer is a pyramid layer and is formed by tiling triangular pyramids or rectangular pyramids, the vertexes of the triangular pyramids form regular triangle arrangement, the vertexes of the rectangular pyramids form square arrangement, the height T of the pyramid is 10-100 mu m, and the included angle between the side surface and the height is 30-60 degrees;

The light homogenizing film is a micro-lens light homogenizing film, and the micro-lens light homogenizing film comprises a light splitting layer, a substrate layer and a light expanding layer. The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer. The light expansion layer is a micro lens layer, in the micro lens layer, coordinates of main optical axes of three adjacent micro lenses are connected to form an regular triangle array, and the micro lenses in the micro lens array are closely arranged. The width of the micro lens is 10-100 mu m, the height of the micro lens is H, the height-width ratio H/G is 0.05-0.5, and the distance D between the main optical axes of adjacent micro lenses is equal to G.

The light-splitting layer and the light-expanding layer are made of transparent polymer resin.

The transparent polymer resin is made of one selected from AR (Acrylic resin or modified Acrylic resin), PMMA (polymethyl methacrylate) or PC (polycarbonate). AR is preferably a photo-curing process, and PMMA and PC are preferably hot-press molding processes.

The transparent polymer resin of the light splitting layer is one selected from AR, PC or PMMA, and has refractive index n ₁ Selected from 1.4 to 1.65.

When the light expansion layer is a prism layer, a cylindrical lens layer, a pyramid layer or a micro lens layer, the transparent polymer resin is selected from one of AR, PC or PMMA, and has a refractive index n ₂ Selected from 1.4 to 1.65.

The invention provides a light homogenizing film, which comprises a substrate layer 20 and a light splitting layer 21, wherein a light expansion layer 22 is not present, and the light homogenizing film is a plane light homogenizing film as shown in fig. 10. The thickness M of the matrix layer 20 is 25-500 μm, such as 25 μm,75 μm,100 μm,125 μm,250 μm,500 μm, the matrix layer is made of one of PET, PMMA or PC, the light splitting layer is made of transparent polymer resin, the material is one of photo-cured Acrylic Resin (AR), PMMA or PC, and the refractive index n ₁ 1.4-1.65, e.g. 1.4, 1.5,1.58, 1.65. The light splitting layer is designed by a single-axis standard surface: the long ribs are overlapped and formed by N long ribs in the directions, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, and the topological coefficient N is 1, namely uniaxial light splitting is carried out (shown in figure 6); the light splitting layer is selected from standard surface light splitting layers, and the corresponding isosceles triangle with long rib cross section has limited left and right waists at two endsThe straight line is taken, that is, the cross section of the long rib is an isosceles triangle, and the vertex angle theta is 60-120 degrees, such as 60 degrees, 75 degrees, 80 degrees, 90 degrees, 105 degrees and 120 degrees. When the light splitting layer is a convex arc surface light splitting layer or a concave arc surface light splitting layer, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively an outer convex arc line (called convex arc line for short) and an inner concave arc line (called concave arc line for short) which are cut off at two ends in a limited way, the vertex angle theta is 60-120 degrees, such as 60 degrees, 80 degrees, 87 degrees, 90 degrees, 100 degrees and 120 degrees, and the central angle alpha is 1-30 degrees, such as 1 degrees, 3 degrees, 10 degrees and 30 degrees. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=30-120%. The foregoing technical solutions include examples 1 to 31.

The invention provides a light homogenizing film, which comprises a substrate layer 20, a light splitting layer 21 and a light expanding layer 22, as shown in fig. 11, wherein the light homogenizing film is a prism light homogenizing film. The thickness M of the matrix layer 20 is 25-500 μm, such as 25 μm,75 μm,250 μm,500 μm, the matrix layer is made of one of PET, PMMA or PC, the spectroscopic layer is made of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.4-1.65, e.g. 1.4, 1.5, 1.65. The light splitting layer is designed by a biaxial standard surface: the light-emitting diode is formed by superposing long ribs in N directions, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, namely biaxial light splitting (shown in figure 7); the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light expansion layer is a prism layer 221, and is formed by tiling triangular prism ribs, wherein the cross section of each triangular prism rib is an isosceles triangle, the base V of the triangle is 10-100 μm, such as 10 μm,25 μm,50 μm,75 μm and 100 μm, and the vertex angle beta is 60-120 degrees, such as 60 degrees, 75 degrees, 90 degrees, 105 degrees and 120 degrees; the light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=91-302%. The foregoing technical solutions include examples 37 to 48.

The invention provides a dodging film, which comprises a substrate layer 20 and a beam splitterLayer 21 and light-spreading layer 22, as shown in fig. 12, the light-homogenizing film is a lenticular light-homogenizing film. The thickness M of the matrix layer 20 is 25-500 μm, such as 25 μm,75 μm,125 μm,250 μm,500 μm, the matrix layer is made of PET, PMMA or PC, the light splitting layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.4-1.65, e.g. 1.4, 1.5, 1.65. The light splitting layer is designed by a biaxial standard surface: the long ribs are stacked in N directions, are tiled on the lower surface of the matrix layer, extend towards two ends infinitely, are closely arranged in the same direction, and have a topological coefficient N selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light expansion layer is a columnar lens layer 222, and is formed by tiling columnar lens ribs, the cross section of the columnar lens is an arc, the width (chord length) F of the arc is 20-1000 μm, for example, 20 μm,50 μm,100 μm,250 μm,500 μm,1000 μm, the height of the arc is K, and the height-width ratio K/F is 0.05-0.5, for example, 0.05, 0.1, 0.3 and 0.5. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=97-125%. The foregoing technical solutions include examples 49-60.

The invention provides a light homogenizing film, which comprises a substrate layer 20, a light splitting layer 21 and a light expansion layer 22, as shown in fig. 12, wherein the light homogenizing film is a pyramid light homogenizing film. The thickness M of the matrix layer 20 is 25-500 μm, such as 25 μm, 75 μm, 250 μm, 500 μm, the matrix layer is made of one of PET, PMMA or PC, the spectroscopic layer is made of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.4-1.65, e.g. 1.4, 1.5, 1.65. The light splitting layer is designed by a biaxial standard surface: is formed by superposing long ribs in N directions, the long ribs are flatly paved on the lower surface of the matrix layer, the long ribs extend towards two ends infinitely and are identical in directionThe longitudinal ribs are closely arranged, and the topological coefficient N is selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light spreading layer is a rectangular pyramid layer 224, which is formed by tiling rectangular pyramids, the vertices of which form a square arrangement, the height T of the pyramids being 10-50 μm, e.g. 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, and the angle between the sides and the height being 30 ° -60 °, e.g. 30 °, 45 °, 60 °. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=41-270%. The foregoing technical solutions include examples 61 to 70.

The invention provides a light homogenizing film, which comprises a substrate layer 20, a light splitting layer 21 and a light expanding layer 22, as shown in fig. 13, wherein the light homogenizing film is a micro lens light homogenizing film. The thickness M of the matrix layer 20 is 25-500 μm, such as 25 μm, 75 μm, 250 μm, 500 μm, the matrix layer is made of one of PET, PMMA or PC, the spectroscopic layer is made of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.4-1.65, e.g. 1.4, 1.5, 1.65. The light splitting layer is designed by a biaxial standard surface: the long ribs are stacked in N directions, are tiled on the lower surface of the matrix layer, extend towards two ends infinitely, are closely arranged in the same direction, and have a topological coefficient N selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light expansion layer is a micro lens layer 225, and coordinates of main optical axes of adjacent three micro lenses are connected to form a regular triangle array, and the micro lenses in the micro lens array are closely arranged. The width G of the micro-lenses is 10-100 μm, such as 10 μm, 25 μm, 50 μm, 75 μm, 100 μm, the height of the micro-lenses is H, the height-width ratio H/G is 0.05-0.5, such as 0.05, 0.1, 0.3, 0.5, and the distance D between the main optical axes of adjacent micro-lenses is equal to G. The light homogenizing film has good light homogenizing performance and uniformity improving amplitude U=97-1 14%. The foregoing technical solutions include examples 71-80.

The invention provides a preparation method of a uniform light film, which is characterized in that a micro-replication or hot-press molding process is adopted on the back surface of a matrix layer, a light-splitting layer is prepared by utilizing transparent polymer resin, and a light-curing micro-replication or hot-press molding process is adopted on the front surface of the matrix layer, so that a light-expanding layer is prepared by adopting a transparent polymer resin formula.

Further, the preparation method of the dodging film comprises the following steps:

(1) Preparing a light splitting layer on the back surface by taking the matrix layer as a supporting layer to obtain a planar light homogenizing film only comprising the light splitting layer and the matrix layer;

(1) Preparing a mold 1 of the light splitting layer;

(2) Using the substrate layer as a supporting layer, and performing micro-replication or hot-press molding on the back surface of the die 1 to obtain a light-homogenizing film (namely, a planar light-homogenizing film, or a semi-finished product of the light-homogenizing film with other light-expanding layer structures) only comprising the light-homogenizing layer and the substrate layer;

(1) Preparing a light splitting layer on the back surface by taking the substrate layer as a supporting layer to obtain a semi-finished product containing the light splitting layer;

(2) Preparing a light-spreading layer on the front surface of the semi-finished product prepared in the step (1) to obtain a light-homogenizing film simultaneously containing the light-splitting layer and the light-spreading layer;

(1) The mold 1 (concave long rib superposition texture) for preparing the light splitting layer is generally manufactured by polishing a metal roller or a metal plate through a diamond engraving process, wherein the shape of a diamond engraving knife is the same as the cross section of the long rib;

(2) Micro-copying or hot-pressing the back of the matrix layer by using a die 1 to form a light splitting layer (overlapped textures of the convex long ribs) to obtain a semi-finished product containing the light splitting layer;

(3) The mold 2 for preparing the light-expanding layer (complementary structure of the light-expanding layer) is generally manufactured by polishing a metal roller or a metal plate through the processes of bead sand blasting, diamond engraving and the like;

(4) Micro-copying or hot-press molding the front surface of the matrix layer by utilizing a mold 2 to obtain a light-spreading layer, thereby obtaining a light-homogenizing film simultaneously containing the light-splitting layer and the light-spreading layer;

(3) The mold 2 for preparing the light-expanding layer (the light-expanding layer has the same structure) is generally manufactured by polishing a metal roller or a metal plate through the processes of bead sand blasting, diamond engraving and the like;

(4) The mold 3 (complementary structure of the light-expanding layer) for preparing the light-expanding layer can be stamped by the mold 2 (low-hardness metal is extruded by high-hardness metal) to obtain a metal mold, or an optical film with the same structure of the light-expanding layer is used as a template for electroforming the metal mold with the complementary structure, or the optical film with the complementary structure is stamped by the mold 2 and directly used as the soft mold 3;

(5) Micro-copying or hot-press molding the front surface of the matrix layer by utilizing a mold 3 to obtain a light-spreading layer, thereby obtaining a light-homogenizing film simultaneously containing the light-splitting layer and the light-spreading layer;

it should be noted that the processing manner of the light splitting layer and the light expanding layer should be selected according to the kind of structure and the kind of material, and the present invention is not preferable.

It should be noted that the preparation method of the dodging film provided by the invention is suitable for the production of sheets and also suitable for the production of coiled materials.

The light homogenizing film can be used as an optical functional material for a backlight system of a direct type LED array. The LED backlight module is particularly suitable for a Mini LED backlight source and is used for improving the lamp shadow problem of a point light source array with high brightness and short OD. OD represents the distance of the point light source from the nearest optical film to the point light source in the backlight structure. Short OD may mean OD less than 1mm, even zero.

Compared with the prior art, the dodging film provided by the invention can reasonably distribute the energy concentrated in the beam center of the point light source, especially in the beam angle of 30 degrees, to other directions, and reduce the energy of the central bright spot on the projection screen and enlarge the whole luminous area, so that the uniformity of energy distribution is improved by at least 30%.

In some larger size (e.g., TV, monitor) Mini LED backlight applications, because of the larger lamp spacing (typically greater than 5 mm), in order to still pursue ultra-thin designs with short OD and even zero OD at such large lamp spacing, a better light homogenizing film product is needed, which further enhances the light homogenizing effect even at the expense of some brightness.

The blue light can be selectively reflected through the base film (the light filtering matrix layer) with the light filtering function, so that the blue light is mixed between the lamp and the light filtering matrix layer for multiple times, namely, the blue light is reflected back and forth for multiple times (as shown in fig. 15), the light propagation path (as shown in fig. 16) is indirectly increased, namely, the OD (light mixing distance) is equivalently increased, and the light homogenizing effect can be effectively improved.

The blue light is reflected by the filter matrix layer at smaller angles of incidence, and at larger angles of incidence, the reflectance decreases and blue light transmission begins (as is the case for filters of the multilayer film principle, the spectrum is dependent on the angle of incidence, as shown in fig. 17 a/b). Therefore, as shown in fig. 15, the main principle of multiple light mixing is that the lower surface of the filter substrate layer is subjected to specular reflection, the direction is not changed, diffuse reflection is generated at the reflecting surface of the lamp panel, the direction is changed, the incident angle is gradually increased, and the final transmission ratio is higher.

The invention provides a composite light homogenizing film which comprises a light filtering substrate layer, a composite adhesive layer, a light splitting layer and a substrate layer, wherein the light splitting layer is positioned on the lower surface of the substrate layer, the composite adhesive layer is positioned on the upper surface of the light filtering substrate layer, and the tip of the light splitting layer is combined with the composite adhesive layer.

The invention provides a composite light homogenizing film which sequentially comprises a light filtering substrate layer, a composite adhesive layer, a light splitting layer and a substrate layer from bottom to top, wherein the light splitting layer is positioned on the lower surface of the substrate layer, the composite adhesive layer is positioned on the upper surface of the light filtering substrate layer, and the tip of the light splitting layer is combined with the composite adhesive layer.

The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer and a concave cambered surface light splitting layer.

The light splitting layer is formed by overlapping long ribs in N directions, N is a topological coefficient, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, the N directions equally divide 360 degrees of azimuth angles, namely the angle intervals between the adjacent directions are 180/N degrees, and N is selected from 2 or 3.

The surface of the light splitting layer has high smoothness and less abnormal deflection of light. Further, the line roughness Ra of the surface of the light splitting layer is less than 250nm.

Further, the filter substrate layer can reflect blue light.

Further, the filtering matrix layer is a multilayer co-extruded polymer film, the filtering effect is that blue light is reflected at a smaller incident angle (smaller than a critical angle), the reflection proportion is reduced at a larger incident angle (larger than the critical angle), and the blue light is gradually transmitted.

Further, the multilayer co-extruded polymer film is formed by alternately superposing a polymer with a high refractive index and a polymer with a low refractive index. The refractive index and thickness of each layer are not limited, but the above-mentioned filtering effect is required to be satisfied.

Furthermore, the spectral characteristics of the filter substrate layer, such as the reflection band, the reflectivity and the critical angle, are not limited, and the light homogenizing effect can be realized as long as the reflection band can cover the wavelength range of the blue light source.

Further, the thickness of the filter substrate layer is not limited, and the number of layers and the thickness of each layer are finally determined by the spectral characteristics, so that the total thickness is determined.

Further, the thickness of the composite adhesive layer is selected from 0.5-5 mu m.

Further, the composite adhesive layer is made of transparent polymer resin, and is made of photo-cured Acrylic Resin (AR), and the refractive index is selected from 1.45-1.55.

The invention provides a composite light homogenizing film which sequentially comprises a matrix layer, a light splitting layer, a composite adhesive layer and a light filtering matrix layer from top to bottom, wherein the matrix layer and the light splitting layer form a planar light homogenizing film, namely the composite light homogenizing film can be understood to be formed by the planar light homogenizing film, the composite adhesive layer and the light filtering matrix layer. The thickness M of the matrix layer is 25-500 μm, for example, 25 μm,75 μm,100 μm,125 μm,250 μm, or 500 μm, and the material of the matrix layer is selected from one of PET, PMMA or PC; the light splitting layer is made of transparent polymer resin, and is made of one of photo-cured Acrylic Resin (AR), PMMA or PC, and has refractive index n ₁ 1.4 to 1.65, for example 1.4, 1.5, 1.58 or 1.65; the composite adhesive layer is made of transparent polymer resin, is also light-cured Acrylic Resin (AR), and has a refractive index of 1.45-1.55, for example, 1.45, 1.5 or 1.55 and a thickness of 0.5-5 μm, for example, 0.5 μm,1 μm or 5 μm; the filtering matrix layer is a multilayer co-extruded polymer film, the filtering effect is that blue light is reflected at a smaller incident angle (smaller than a critical angle), the reflection proportion is reduced at a larger incident angle (larger than the critical angle), and the blue light is gradually transmitted. The light splitting layer is formed by superposing long ribs in N directions, the long ribs are tiled on the lower surface of the matrix layer, the long ribs extend towards two ends infinitely, the long ribs in the same directions are closely arranged, and the topological coefficient N is 2 or 3; the light splitting layer is selected from one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer, the left and right waists of the isosceles triangle with the cross section of the long rib corresponding to the standard surface light splitting layer are respectively straight lines with limited interception at two ends, namely the cross section of the long rib is a straight triangle, the vertex angle theta is 60-120 degrees, such as 60 degrees, 75 degrees, 90 degrees, 105 degrees or 120 degrees. When the light splitting layer is a convex arc surface light splitting layer (the cross section is a convex arc side triangle), the vertex angle theta is 91-120 degrees, such as 91 degrees, 93 degrees, 100 degrees, or 120 degrees, and the central angle alpha is 1-30 degrees, such as 1 degrees, 3 degrees, 10 degrees, or 30 degrees. When the light splitting layer Is a concave cambered surface light splitting layer (the cross section is a concave cambered side triangle), the vertex angle theta is 60-89 degrees, such as 60 degrees, 80 degrees, 87 degrees, or 89 degrees, and the central angle alpha is 1-30 degrees, such as 1 degrees, 3 degrees, 10 degrees, or 30 degrees. The light homogenizing film has good light homogenizing performance and the uniformity improvement range U is 178-575%. The foregoing technical solutions include examples 81-120.

The invention provides a preparation method of a composite dodging film, which adopts a micro-replication or hot-press molding process on the back surface of a matrix layer, and prepares a light-splitting layer by using transparent polymer resin; a coating process is adopted on the front surface of the optical filtering matrix layer, and a transparent polymer resin is utilized to prepare a composite adhesive layer which is compounded with the light splitting layer; and after the tip part of the light splitting layer is embedded into the composite adhesive layer, ultraviolet curing is carried out to combine the light filtering matrix layer with the light splitting layer.

Further, the preparation method of the composite dodging film comprises the following steps:

(3) Unreeling the optical filtering matrix layer on a first unreeling station, coating a composite adhesive layer (uncured) on the front surface of the optical filtering matrix layer to obtain a semi-finished product containing the composite adhesive layer, and unreeling the semi-finished product of the light splitting layer on a second unreeling station;

(4) The two rolls of semi-finished products are stacked and compounded through tension or pressure, the tip of the light splitting layer is embedded into the composite adhesive layer, and the composite adhesive layer is rapidly cured through ultraviolet curing equipment, so that the composite adhesive layer is firmly combined with the tip of the light splitting layer;

(5) Winding on a first winding station to obtain a composite dodging film finished product;

the composite dodging film can be used as an optical functional material for a backlight system of a direct type LED array. Is particularly suitable for application of Mini LED backlight sources with larger size (such as TV and Monitor) and is used for improving the lamp shadow problem of a point light source array with large space, high brightness and short OD.

Compared with the prior art, the composite dodging film provided by the invention can reasonably distribute the energy concentrated in the beam center of the point light source, especially in the beam angle of 30 degrees, to other directions, and reduce the energy of the central bright spot on the projection screen and enlarge the whole luminous area, so that the uniformity of energy distribution is improved by at least 178%.

It is found that when the light-expanding layer and the light-splitting layer of the composite light-homogenizing film are of specific structures, the collocation angle between the light-expanding layer and the light-splitting layer has a certain influence on the light-homogenizing performance, and the influence on the angle collocation of the central light beam most concentrated by the light source becomes larger. When the topological coefficient n=2 of the spectroscopic layer (the direction in which the long rib of the spectroscopic layer extends is ω ₁ 、ω ₂ ) The light-expanding layer is a prismatic layer (the extending direction of the triangular prism rib is omega) ₄ ) And the matching angle delta omega of the light expansion layer and the light splitting layer (delta omega=omega) ₄ -ω ₁ ) When the light homogenizing film is placed on 4 beam angle light sources of 30 degrees at 0/15/30/45 degrees, the change of the illuminance distribution is shown in fig. 19, and the change of RSD is shown in fig. 20. It can be seen that as Δω increases from 0 to 45 degrees, the dodging effect on the luminance map continues to improve and RSD continues to decrease.

In order to weaken LED lamp shadow and improve uniformity, the invention provides an oblique-crossing composite light homogenizing film and a preparation method thereof.

The invention provides an oblique-crossing composite light-homogenizing film which comprises a light-filtering substrate layer, a composite adhesive layer, a light-splitting layer, a substrate layer and a light-expanding layer.

The surface of the light splitting layer has high smoothness and less abnormal deflection of light.

Further, the material of the matrix layer is selected from one of PET, PMMA or PC; the light splitting layer is made of transparent polymer resin, and is made of photo-cured Acrylic Resin (AR) with refractive index n ₁ 1.5; the light-expanding layer is made of transparent polymer resin, and is made of photo-cured Acrylic Resin (AR) with refractive index n ₂ 1.4-1.65.

The topological coefficient N of the light splitting layer is 2.

The extending direction omega of the long rib of the light splitting layer ₁ Can be set to 0 degree omega ₂ 90 degrees.

The light expansion layer is an oblique prism layer, and the extending direction omega of the triangular prism rib of the oblique prism layer ₄ And the extending direction omega of the long rib of the light splitting layer ₁ /ω ₂ The angle delta omega=omega is 45 degrees oblique or approximately 45 degrees, and the matching angles delta omega=omega are matched in two directions ₄ -ω ₁ 30 to 60 °, preferably 45 °.

The oblique prism layer is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle, the bottom side V of the triangle is 10-100 mu m, and the vertex angle beta is 60-120 degrees.

Further, the cross prism layer is composed of a transparent polymer resin. The transparent polymer resin is selected from AR, refractive index n ₂ Selected from 1.4 to 1.65.

Further, the oblique-crossing composite light-homogenizing film comprises a light-filtering matrix layer, a composite adhesive layer, a light-splitting layer, a matrix layer and a light-expanding layer from bottom to top, wherein the light-splitting layer is positioned on the lower surface of the matrix layer, the composite adhesive layer is positioned on the upper surface of the light-filtering matrix layer, and the tip of the light-splitting layer is combined with the composite adhesive layer; the light splitting layer comprises N long ribs in N directions, and N is 2; the light-expanding layer is an oblique prism layer, the oblique prism layer comprises a plurality of triangular prism ribs, and the extending direction omega of the triangular prism ribs ₄ The extending direction of the long rib of the light splitting layer is omega ₁ And omega ₂ The collocation angle delta omega = omega of the triangular prism rib and the long rib direction ₄ -ω ₁ Delta omega is 30-60 degrees. Δω is preferably 45 °. The light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer.

In the oblique-crossing composite light-homogenizing film, the light-splitting layer is formed by overlapping long ribs in N directions, N is a topological coefficient, the topological coefficient of the light-splitting layer is 2, and the light-splitting layer is one of a standard surface light-splitting layer, a convex cambered surface light-splitting layer and a concave cambered surface light-splitting layer.

In the oblique-crossing composite light-homogenizing film, the oblique-crossing prism layer is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom side V of the triangle is 10-100 mu m, and the vertex angle beta is 60-120 degrees. Preferably, the apex angle β is 75 °.

The extending direction omega of the long rib of the light splitting layer ₁ Can be set to 0 DEG omega ₂ 90 deg..

In the oblique-crossing composite light-homogenizing film, the oblique-crossing prism layer is composed of transparent polymer resin; the transparent polymer resin is selected from AR, refractive index n ₂ 1.4 to 1.65; the light splitting layer is formed by superposing long ribs in N directions, N is a topological coefficient, the long ribs are tiled on the lower surface of the matrix, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, the N directions equally divide 360 degrees of azimuth angles, namely, the angle intervals between the adjacent directions are 180/N degrees, and N is 2; the long ribs in the light splitting layer have the same cross section and are isosceles triangles, the left waist and the right waist are one of straight lines, convex arcs or concave arcs which are cut off at two ends in a limited way, the bottom edge is a straight line, and the bottom edge W ₁ 10-100 mu m, and the vertex angle theta is 60-120 degrees; the bending degree of the convex arc line and the concave arc line is expressed by adopting a central angle, and the central angle alpha is 1-30 degrees; the light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer, and the waist of the isosceles triangle with the corresponding long rib cross section is a straight line, a convex arc line (called convex arc line for short) and a concave arc line (called concave arc line for short) which are cut out by two ends in a limited way respectively.

Further, the filter substrate layer can reflect blue light.

The invention provides a composite dodging film, which comprises a substrate layer 20, a light splitting layer 21, a light expanding layer 22, a composite glue layer 24 and a light filtering substrate layer 23, as shown in fig. 21 and 22, wherein the composite dodging film is an oblique-crossing composite dodging film. The thickness M of the matrix layer 20 is 25-500 μm, such as 25 μm, 75 μm, 250 μm, 500 μm, the matrix layer is made of one of PET, PMMA or PC, the spectroscopic layer is made of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.4-1.65, for example 1.4, 1.5 and 1.65, wherein the composite adhesive layer is composed of transparent polymer resin, is made of photo-cured Acrylic Resin (AR), has a refractive index of 1.5 and a thickness of 1 mu m, and the light filtering matrix layer is a multilayer co-extrusion polymer film, has the light filtering effect of reflecting blue light at a small incident angle (smaller than a critical angle), has a reduced reflection proportion at a large incident angle (larger than the critical angle), and gradually starts to transmit the blue light. The light splitting layer is designed by a biaxial standard surface: the light-emitting diode is formed by superposing long ribs in N directions, the long ribs are flatly paved on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, and the topological coefficient N is 2, namely biaxial light splitting and omega ₂ And omega ₁ Perpendicular. When the light splitting layer is a standard plane light splitting layer, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely the cross section of the long rib is a straight triangle, the vertex angle theta is 60-120 degrees, for example 60 degreesDegree, 75 °, 90 °, 105 °, 120 °. The light spreading layer is an oblique prism layer 223, and is formed by tiling triangular prism ribs, wherein the cross section of each triangular prism rib is isosceles triangle, the base V of the triangle is 10-100 μm, such as 10 μm, 25 μm, 50 μm, 75 μm and 100 μm, and the vertex angle beta is 60-105 degrees, such as 60 degrees, 75 degrees, 80 degrees, 85 degrees, 90 degrees and 105 degrees. The angle delta omega (i.e. omega) between the light-spreading layer and the light-splitting layer ₄ -ω ₁ ) 30 ° -60 °, e.g. 30 °, 45 °, 60 °. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range U=247-812%. When the light splitting layer is a convex arc surface light splitting layer or a concave arc surface light splitting layer, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively a convex arc line (called convex arc edge for short) and a concave arc line (called concave arc edge for short) which are cut off at two ends in a limited way, the vertex angle theta is 75 degrees, and the central angle alpha is 1-30 degrees, such as 1 degree and 30 degrees; the light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=737-812%. The foregoing technical solutions include embodiments 121-143.

The invention provides a preparation method of an oblique-crossing composite light homogenizing film, which comprises the steps of adopting a micro-replication or hot-press molding process on the front surface of a matrix layer, and preparing a light-expanding layer by using transparent polymer resin; the back of the matrix layer adopts micro-replication or hot-press molding process, and the transparent polymer resin is utilized to prepare the spectroscopic layer; a coating process is adopted on the front surface of the optical filtering matrix layer, and a transparent polymer resin is utilized to prepare a composite adhesive layer which is compounded with the light splitting layer; and after the tip part of the light splitting layer is embedded into the composite adhesive layer, ultraviolet curing is carried out to combine the light filtering matrix layer with the light splitting layer.

Further, the preparation method of the oblique-crossing composite dodging film comprises the following steps:

(1) The mold 1 (concave long rib texture) for preparing the light splitting layer is generally obtained by polishing a metal roller or a metal plate through a diamond engraving process, wherein the shape of a diamond engraving knife is the same as the cross section of the long rib, and the engraving direction or the extending direction omega ₁ 0 degree omega ₂ 90 degrees;

(2) Micro-copying or hot-pressing the back of the matrix layer by using a die 1 to form a light splitting layer (convex long rib texture) to obtain a semi-finished product containing the light splitting layer;

(3) Mould 2 for preparing light-expanding layer(concave triangular prism structure) is generally obtained by polishing a metal roller or a metal plate through a diamond engraving process, and engraving direction or extending direction omega ₄ Is omega ₁ +△ω；

(4) Using a die 2 to micro copy or hot press the front surface of the semi-finished product matrix layer to form a light-spreading layer (convex triple prism structure) so as to obtain a uniform light film semi-finished product containing a light-spreading layer and a light-spreading layer;

(5) Unreeling the optical filtering matrix layer on a first unreeling station, coating a composite adhesive layer (uncured) on the front surface of the optical filtering matrix layer to obtain a semi-finished product containing the composite adhesive layer, and unreeling the uniform optical film semi-finished product on a second unreeling station;

(6) The two rolls of semi-finished products are stacked and compounded through tension or pressure, the tip of the light splitting layer is embedded into the composite adhesive layer, and the composite adhesive layer is rapidly cured through ultraviolet curing equipment, so that the composite adhesive layer is firmly combined with the tip of the light splitting layer;

(7) Winding on a first winding station to obtain an oblique-crossing composite uniform light film finished product;

the oblique-crossing composite dodging film can be used as an optical functional material for a backlight system of a direct-type LED array. Is particularly suitable for application of Mini LED backlight sources with larger size (such as TV and Monitor) and is used for improving the lamp shadow problem of a point light source array with large space, high brightness and short OD.

Compared with the prior art, the oblique-crossing composite light homogenizing film provided by the invention can reasonably distribute the energy concentrated at the beam center of the point light source, especially within 30 degrees of the beam angle, to other directions, and reduce the energy of the central bright spot on the projection screen and enlarge the whole luminous area, so that the uniformity of energy distribution is improved by at least 247%. The oblique-crossing composite light homogenizing film provided by the invention can weaken the LED lamp shadow and improve the uniformity.

Drawings

FIG. 1 is a typical contrast of the dodging effect of a diffuser/dodging film (a light source, b light source + diffuser, c light source + dodging film);

FIG. 2 is a schematic diagram of a light uniformity performance evaluation architecture for a light uniformity film;

FIG. 3 shows a method for evaluating spectral effect of a light homogenizing film (a spherical coordinate system, b lambertian body light source, c lambertian body light source+light homogenizing film);

FIG. 4 is a schematic diagram of the composition and cross section of a light homogenizing film (a matrix layer+spectroscopic layer, b matrix layer+spectroscopic layer);

fig. 5 is a schematic diagram of the light splitting action principle (a) and the light spreading action principle (b);

fig. 6 is a design principle of a long rib superposition (n=1) of a light splitting layer (a long rib superposition mode b light splitting structure details c light splitting effect d light splitting effect details are enlarged);

fig. 7 is a design principle of a long rib superposition (n=2) of a light splitting layer (a long rib superposition mode b light splitting structure details c light splitting effect d light splitting effect details are enlarged);

fig. 8 is a design principle of a long rib superposition (n=3) of a light splitting layer (a long rib superposition mode b light splitting structure details c light splitting effect d light splitting effect details are enlarged);

FIG. 9 is a schematic diagram of a cross section of a long rib of different shape (a three perspective views b of a cross section of a convex arc side triangle c of a cross section of a straight triangle d of a cross section of a concave arc side triangle);

FIG. 10 is a schematic view of a three-dimensional structure of a planar light homogenizing film;

FIG. 11 is a schematic view of a prism light-homogenizing film in cross section;

FIG. 12 is a schematic view of a cylindrical lens cross section and a cylindrical lens structure of a cylindrical lens dodging film;

FIG. 13 is a schematic view of a three-dimensional structure of a pyramid light homogenizing film and a rectangular pyramid structure;

FIG. 14 is a schematic view of a three-dimensional structure of a microlens light homogenizing film and a microlens structure;

FIG. 15 is a schematic diagram of the reflection of light from a light-filtering matrix layer and the transmission of light from a light-filtering matrix layer to a light-filtering matrix layer;

FIG. 16 is a schematic diagram of an equivalent increase in OD of multiple reflection light (specular reflection of the filter matrix layer, diffuse reflection of the lamp panel);

FIG. 17a is a graph of visible light transmittance of a filter substrate layer at different angles of incidence (AOI);

FIG. 17b is a graph of blue reflectance of a filter substrate layer at different angles of incidence (AOI);

FIG. 18 is a schematic diagram of the composition and cross-section of a composite light homogenizing film.

Fig. 19 shows the effect of the matching angle of the prism light-spreading layer and the light-splitting layer (n=2) on the illuminance distribution;

fig. 20 shows the effect of the matching angle of the prism light-spreading layer and the light-splitting layer (n=2) on RSD.

FIG. 21 is a schematic cross-sectional view of a perspective structure and prism ribs of a diagonal composite dodging film;

fig. 22 is a top view of a diagonal composite dodging film.

Wherein:

0: an LED lamp panel; 1: an LED;00: an LED lamp panel; 01: an LED;2: a light homogenizing film; 3: an absorbing screen;

20: a base layer; 21: a light splitting layer; 22: a light-spreading layer; 23: a light filtering substrate layer; 24: a composite adhesive layer;

40: inputting light; 411: penetrating light; 412: recovering light; 42: outputting light; 43: secondary input light

50: long rib/short rib ridges; 51: valleys between long ribs/short ribs;

221: a prismatic structure; 222: a lenticular structure; 224: a rectangular pyramid structure; 225: microlens structures. 223: a skew prism layer;

2201: front prism rib peaks; 2202: front prism rib wave trough; 2101: back long rib peak (omega) ₁ ) The method comprises the steps of carrying out a first treatment on the surface of the 2102 back long rib trough (omega) ₁ ) The method comprises the steps of carrying out a first treatment on the surface of the 2103: back long rib peak (omega) ₂ ) The method comprises the steps of carrying out a first treatment on the surface of the 2104 back long rib trough (omega) ₂ )；

MD: the extension direction of the coiled material, namely the machine direction (Machine Direction); omega: the structure engraving direction or extending direction is at a clockwise deflection angle to the MD.

Detailed Description

For a better understanding of the structure and the functional features and advantages achieved by the present invention, preferred embodiments of the present invention are described below in detail with reference to the drawings.

The invention provides a light homogenizing film, wherein a light splitting layer of the light homogenizing film plays a light splitting role, a light expanding layer plays a main light expanding role, and a matrix layer can play a certain light expanding role if the light expanding layer is not provided. The main principle is shown in fig. 5.

Taking a planar light homogenizing film as an example, fig. 5a shows the light splitting process that occurs after the normal input light 40 is incident on the light splitting layer 21, since the main light of the light source is concentrated in the normal direction. The light is incident through the inclined outer surfaces on both sides of the light splitting layer, so as to generate deflection in at least two directions (different numbers according to the structure of the light splitting layer, if the rectangular pyramid is actually in four directions), the generated incident light 411 is transmitted inside the light homogenizing film, is emitted from the upper surface of the substrate layer 20, and is deflected again (light density to light sparseness), so that output light 42 after further separation is generated, which is the basic principle of the light splitting process. A beam of light of the point light sources is dispersed after passing through the beam splitting layer, and the light beams of the point light sources are dispersed by the beam splitting layer, and the dispersed light is overlapped with each other, so that the output light is more uniform.

Taking a planar light homogenizing film as an example, a small amount of light rays with a large angle are inclined to enter the light splitting layer, and fig. 5b shows a light spreading process occurring after the input light 40 with 45 degrees enters the light splitting layer 21. Taking the right side ray as an example, the ray enters right through the inclined outer surface of the light splitting layer, is transmitted and transmitted to the upper surface of the substrate layer, and is totally reflected to generate recovered light 412 because the angle meets the total reflection critical angle, and part of the ray passes out of the light splitting layer, and is diffusely reflected at the bottom lamp panel to generate upward secondary input light 43. When this part of the light reaches the splitting layer again, it is pulled a considerable horizontal distance away from the position of the original input light 40, or it can be understood that this repeated light circulation up and down indirectly enlarges the vertical mixing distance, which in summary allows the light energy to be distributed to a larger area, which is the basic principle of the light expansion process.

Although the light splitting effect is mainly generated for a single plane light homogenizing film, the proportion of the light expanding effect is small, after a plurality of light homogenizing films are stacked, the proportion of the light expanding effect can be increased by inclining the input light book of the upper light homogenizing film.

In general, in order to meet the design principle of the actual light path, and particularly when a plurality of stacked structures are assembled, the proportion of the transmitted light and the total reflection light of each layer is ensured, the surface finish degree of the structures of the light splitting layer and the light expanding layer is required to be as high as possible, and the line roughness is as low as possible so as to reduce the abnormal deflection of the light.

The preparation of the structure of the light splitting layer should be optimal by the stamping molding of a precise engraving die, and other laser, photoetching and other preparation methods cannot guarantee the high-precision surface. The structural design of the light splitting layer adopts the principle of superposition of long ribs, as shown in fig. 6, 7 and 8, the long ribs can also be understood as grooves left by cutting of a diamond carving knife. The long rib shape may be different (as shown in fig. 9 a), and the cross section thereof may be triangular in three forms as shown in fig. 9b, 9c and 9 d.

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

(A) Illuminance distribution and relative standard deviation

As shown in fig. 2, the light equalizing member 2 is disposed above the LED lamp panel and the LEDs 0, and below the projection screen or absorber 3. The LED lamp panel has a reflecting function, a reflecting sheet or a reflecting coating is integrated, the luminous area S1=60×60 μm of a single LED, the size of the absorption screen is infinite, and the vertical distance Z=500 μm between the absorption screen and the LED. The illuminance distribution on the absorbing screen in the investigation range s2=1200 μm×1200 μm was analyzed by optical simulation methods such as Light tools and the relative standard deviation RSD (Relative Standard Deviation) was calculated.

Note 1: the setting and actual conditions are reduced to about 1/5 scale in equal proportion, and equivalent evaluation is not affected;

and (2) injection: since the addition of the light homogenizing component can change the luminous flux and the radiation receiving total of the investigation range, the change degree of different optical components is different, so that the influence caused by the change of the base number can be eliminated by evaluating the relative standard deviation rather than directly using the standard deviation. (relative standard deviation=standard deviation/mean)

And (3) injection: the light source is set as cosine illuminant, beam angle is 30 degree.

(B) Light homogenizing performance

It is apparent that the lower the RSD, the smaller the difference between the illuminance value and the average value for each site, and the more uniform the illuminance distribution. RSD when no dodging component is to be included ₀ RSD after adding the dodging component as 100% of the reference value ₁ As a measurement value, the increase amplitude u= (RSD) of the uniformity ₀ /RSD ₁ -1) x 100%, and U can be used as an evaluation index of the light homogenizing performance of the light homogenizing component.

Note that: in the standard architecture described in (A), RSD ₀ ＝5.47

(C) Beam morphology

As shown in fig. 3a, a typical spherical coordinate system is shown, where the center of a sphere is used as the origin of light source emission, and the Z-axis is used as the direction of emission, so that the spherical coordinate system can be used to describe the beam form of the initial light source or the beam form after passing through the light homogenizing component. Fig. 3b shows the beam pattern of a lambertian point light source (original LED lamp), and fig. 3c shows the beam pattern after passing through a planar light homogenizing film.

And (3) injection: because the light homogenizing film can not only use one film, and the backlight structure also has other films (such as a quantum dot film/fluorescent film, a common diffusion film, a brightness enhancement film or a composite film), the beam form is only used as a qualitative consideration of the light splitting effect of the single Zhang Yunguang film, the beam form backlight of the final backlight source depends on the complete optical film lamination, and the problem that the light with a large angle cannot be corrected to the normal finally is avoided when the light homogenizing film is designed.

As shown in fig. 4a, the present invention provides a light homogenizing film, which includes a base layer 20 and a spectroscopic layer 21, the spectroscopic layer being located on the lower surface of the base layer 20.

As shown in fig. 4b, the present invention provides a light homogenizing film, which includes a base layer 20, a light splitting layer 21 and a light spreading layer 22, wherein the light splitting layer is positioned on the lower surface of the base layer 20, and the light spreading layer is positioned on the upper surface of the base layer 20.

Example 1

The invention provides a light homogenizing film, which comprises a substrate layer 20 and a light splitting layer 21, wherein a light expansion layer 22 is not present, and the light homogenizing film is a plane light homogenizing film as shown in fig. 10. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate layer is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5. The light splitting layer is designed by a single-axis standard surface: the long ribs are overlapped and formed by N long ribs in the directions, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, and the topological coefficient N is 1, namely uniaxial light splitting is carried out (shown in figure 6); the light splitting layer is selected from standard surface light splitting layers, and the corresponding long rib cross section isoscelesThe left and right waists of the triangle are respectively straight lines which are cut off at the two ends in a limited way, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=46%.

Examples 2 to 36

The planar light homogenizing film as provided in example 1, and the other parameters are listed in table 1.

Table 1 design parameters and light uniformity properties of planar light homogenizing films provided in examples 1 to 36

As shown in table 1, it is clear from comparative examples 1 to 12 that the thickness and the material of the base layer have little influence on the light uniformity performance U of the light-uniformity film, but the material or refractive index of the light-splitting layer has an influence on U, and the higher the refractive index, the more pronounced the light splitting is for the uniaxial light-splitting layer, and the better the light uniformity performance is, the greater the U is. As is clear from comparative examples 13 to 22, the larger the apex angle θ of the triangle in the cross section, the closer the structure is to the plane, the less obvious the light splitting is, the worse the light homogenizing performance is, the smaller U is, and vice versa. Comparative examples 1, 8, 9 and 31 to 36 show that for biaxial and triaxial spectroscopic layer designs, the higher the refractive index, the more pronounced the spectroscopic, the better the dodging properties, the greater the U, and that with the same refractive index, triaxial is better than biaxial than uniaxial. Comparative examples 23 to 30 show that the light splitting effect is still achieved when the waist of the triangle in cross section is curved in different degrees of curvature, and the light homogenizing property U is improved as α is larger (the curvature is larger). Note that in examples 23 to 30, for comparison with example 1, the average inclination angle δ of the side edge is set to 45 degrees (which is consistent with example 1), and when the cross section of example 23 is a convex arc side triangle, δ= (0.5θ+ (0.5θ—α))/2= (120-30)/2=45 degrees, and when the cross section of example 24 is a concave arc side triangle, δ= (0.5θ+ (0.5θ+α))/2= (θ+α)/2= (60+30)/2=45 degrees, and from this result, the arc side design has a certain improvement in light uniformity performance over the straight side design.

Example 37

The invention provides a uniformAs shown in fig. 11, the light film includes a base layer 20, a light splitting layer 21, and a light spreading layer 22, and the light homogenizing film is a prism light homogenizing film. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate layer is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.5. The light splitting layer is designed by a biaxial standard surface: the light-emitting diode is formed by superposing long ribs in N directions, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, namely biaxial light splitting (shown in figure 7); the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light-expanding layer is a prism layer 221, which is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle, the bottom side V of the triangle is 50 mu m, and the vertex angle beta is 90 degrees; the light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=91%.

Examples 38 to 48

The prism light-homogenizing film as provided in example 37, and the other parameters are listed in table 2.

Table 2 design parameters and light uniformity properties of prism light-homogenizing films provided in examples 37 to 48

Note that: examples 37 to 48 the materials of the light-splitting layer and the light-spreading layer were AR

As shown in table 2, it is clear from comparative examples 37 to 42 that the thickness, material, and size of the prism of the light-spreading layer (i.e., width V of the bottom edge) of the base layer have little influence on the light-homogenizing property U of the light-homogenizing film. As is clear from comparative examples 37 and 43 to 45, the apex angle beta of the prism structure has an influence on U, and the light expansion effect is better when the apex angle is smaller than 90 degrees or larger than 90 degrees, and the light homogenizing performance of the light homogenizing film is better and the U is larger. By comparison ofExamples 46 to 48 show that the refractive index n of the prism structure ₂ And also has an effect on the light homogenizing performance.

Example 49

The invention provides a dodging film, which comprises a substrate layer 20, a light splitting layer 21 and a light expansion layer 22, as shown in fig. 12, wherein the dodging film is a cylindrical lens dodging film. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate layer is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.5. The light splitting layer is designed by a biaxial standard surface: the long ribs are stacked in N directions, are tiled on the lower surface of the matrix layer, extend towards two ends infinitely, are closely arranged in the same direction, and have a topological coefficient N selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light expansion layer is a columnar lens layer 222, which is formed by tiling columnar lens ribs, the cross section of the columnar lens is an arc, the width (chord length) F of the arc is 50 mu m, the height of the arc is K, and the height-width ratio K/F is 0.5. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=115%.

Examples 50 to 60

The lenticular light homogenizing film as provided in example 49, and the other parameters are listed in table 3.

TABLE 3 design parameters and light uniformity Properties of cylindrical light homogenizing films provided in examples 49-60

Note that: examples 49 to 60 the spectroscopic and light-spreading layers were all AR

As shown in Table 3, it is clear from comparative examples 49 to 55 that the thickness and material of the base layer and the size of the cylindrical lens of the light-expanding layer (i.e., the arc width F) affect the light-homogenizing property U of the light-homogenizing film Is not large. As is clear from comparative examples 49 and 56 to 58, the height-width ratio K/F of the lenticular lens structure slightly affects U, and the lenticular lens shape is more convex when K/F is larger, the light expansion effect is better, the light uniformity performance of the light-homogenizing film is better, and U is larger. As can be seen from comparative examples 49, 59, 60, the refractive index n of the lenticular structure ₂ The light homogenizing performance is also affected, and the higher the refractive index is, the larger U is.

Example 61

The invention provides a light homogenizing film, which comprises a substrate layer 20, a light splitting layer 21 and a light expansion layer 22, as shown in fig. 12, wherein the light homogenizing film is a pyramid light homogenizing film. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate layer is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.5. The light splitting layer is designed by a biaxial standard surface: the long ribs are stacked in N directions, are tiled on the lower surface of the matrix layer, extend towards two ends infinitely, are closely arranged in the same direction, and have a topological coefficient N selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light spreading layer is a rectangular pyramid layer 224, which is formed by tiling rectangular pyramids, the vertexes of which form a square arrangement, the height T of the pyramid is 30 μm, and the included angle between the side surface and the height is 45 °. The light homogenizing film has good light homogenizing performance and improves the uniformity by the range of U=41%.

Examples 62 to 70

The pyramid light homogenizing film as provided in example 61, and the other parameters are listed in table 4.

TABLE 4 design parameters and light uniformity Properties of pyramid light-homogenizing films provided in examples 61-70

Note that: examples 61 to 70 all had AR as the spectroscopic and light-spreading layer

As shown in table 4, it is clear from comparative examples 61 to 66 that the thickness and material of the base layer and the size of the rectangular pyramid of the light-spreading layer (i.e., T of the pyramid height) have little influence on the light-homogenizing performance U of the light-homogenizing film. As can be seen from comparative examples 61, 67 and 68, the angle between the side face and the high angle is gamma, which has a great influence on U, and the pyramid shape is more convex when gamma is smaller, so that the light expansion effect is better, the light homogenizing performance of the light homogenizing film is better, and U is larger. As is apparent from comparative examples 61, 69, 70, the refractive index n of the quadrangular pyramid structure ₂ The light homogenizing performance is also affected, and the higher the refractive index is, the larger U is.

Example 71

The invention provides a light homogenizing film, which comprises a substrate layer 20, a light splitting layer 21 and a light expanding layer 22, as shown in fig. 13, wherein the light homogenizing film is a micro lens light homogenizing film. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate layer is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.5. The light splitting layer is designed by a biaxial standard surface: the long ribs are stacked in N directions, are tiled on the lower surface of the matrix layer, extend towards two ends infinitely, are closely arranged in the same direction, and have a topological coefficient N selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard surface light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light expansion layer is a micro lens layer 225, and coordinates of main optical axes of adjacent three micro lenses are connected to form a regular triangle array, and the micro lenses in the micro lens array are closely arranged. The width G of the micro lens is 50 μm, the height of the micro lens is H, the height-width ratio H/G is 0.5, and the distance D between the main optical axes of adjacent micro lenses is equal to G. The light homogenizing film has good light homogenizing performance and improves the uniformity by the amplitude U=103%.

The microlens light homogenizing film provided in example 71, and the other parameters are listed in table 5.

TABLE 5 design parameters and light uniformity Properties of microlens light films provided in examples 71-80

And (3) injection: examples 71 to 80 all had AR as the spectroscopic layer and the light-spreading layer

As shown in table 5, it is clear from comparative examples 71 to 75 that the thickness, material, and size of the microlens of the light-spreading layer (i.e., G of pyramid width) have little influence on the light-homogenizing performance U of the light-homogenizing film. As is clear from comparative examples 71 and 76 to 78, the aspect ratio H/G has a certain influence on U, and when the aspect ratio=0.1, the light expansion effect is slightly good, the light uniformity performance of the light-homogenizing film is slightly good, and U is slightly large. As is apparent from comparative examples 71, 79, 80, refractive index n of microlens structure ₂ The light homogenizing performance is also affected, and the higher the refractive index is, the larger U is.

Example 81

The invention provides a composite dodging film, which comprises a substrate layer 20, a light splitting layer 21, a composite glue layer 24 and a light filtering substrate layer 23, as shown in fig. 18, wherein the substrate layer 20 and the light splitting layer 21 form a planar dodging film, i.e. the composite dodging film can be understood as being composed of the planar dodging film, the composite glue layer and the light filtering substrate layer. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate layer is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, wherein the composite adhesive layer is made of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), the refractive index is 1.5, the thickness is 1 mu m, the light filtering matrix layer is a multilayer co-extrusion polymer film, the light filtering effect is that blue light is reflected at a small incident angle (smaller than a critical angle), the reflection proportion is reduced at a large incident angle (larger than the critical angle), and the light filtering matrix layer gradually starts to transmit the blue light. The light splitting layer is designed by a single-axis standard surface: the light-emitting diode is formed by superposing long ribs in N directions, the long ribs are tiled on the lower surface of the substrate layer, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, and the topological coefficient N is 2, namely biaxial light splitting is carried out (shown in figure 7); the spectroscopic layer is selected from standard surface spectroscopic layers corresponding to The left waist and the right waist of the isosceles triangle with the cross section of the long rib are respectively straight lines with limited interception at two ends, namely, the cross section of the long rib is a straight triangle, and the vertex angle theta is 90 degrees. The light homogenizing film has good light homogenizing performance and improves the uniformity by the amplitude U=272%.

Examples 82 to 120

The composite light homogenizing film as provided in example 81, and the other parameters are listed in table 6.

TABLE 6 design parameters and light uniformity Properties of composite light homogenizing films provided in examples 81-120

Note that: the materials of the composite adhesive layers of examples 81-118 are AR, the refractive index is 1.5, the refractive index of the composite adhesive layer of example 119 is 1.45, and the refractive index of the composite adhesive layer of example 120 is 1.55; the filter substrate layer is selected from DC series (such as 47QPD5, 49QPD5, 51QPD5, etc.) with small-angle anti-blue in the east Picasas dimming film product;

as shown in table 6, it is clear from comparative examples 32 and 81 that the light uniformity performance U of the composite light uniformity film was improved significantly when the filter base layer was not increased after the filter base layer was increased. As is clear from comparative examples 81 to 82 and examples 111 and 114 to 116, the thickness and the material of the base layer have little influence on the light homogenizing property U of the light homogenizing film, but the material or refractive index of the light splitting layer has influence on U, and for the biaxial light splitting layer, the higher the refractive index, the more obvious the light splitting, and the better the light homogenizing property, the larger the U. As is clear from comparative examples 93 to 102, the larger the vertex angle θ of the triangle in the cross section, the closer the structure is to the plane, the less obvious the light splitting is, the worse the light homogenizing performance is, the smaller U is, and vice versa. As is clear from comparative examples 81, 88, 89 and 111 to 113, for the triaxial spectroscopic layer design, the higher the refractive index, the more pronounced the spectroscopic, the better the dodging property, the larger the U, and the triaxial is better than biaxial at the same refractive index. As is clear from comparative examples 103 to 110, when the waist of the triangle in cross section is curved in different degrees of radian, the light splitting effect is still achieved, and the light homogenizing performance U is improved as alpha is larger (the curvature is larger). As is clear from comparative examples 81 and 117 to 120, the thickness and refractive index of the composite bond coat have little effect on the light uniformity performance.

Example 121

The invention provides a composite dodging film, which comprises a substrate layer 20, a light splitting layer 21, a light expanding layer 22, a composite glue layer 24 and a light filtering substrate layer 23, as shown in fig. 21 and 22, wherein the composite dodging film is an oblique-crossing composite dodging film. The thickness M of the substrate layer 20 is 75 μm, the substrate layer is made of PET, the spectroscopic layer is made of transparent polymer resin, the substrate is made of photo-cured Acrylic Resin (AR), and the refractive index n ₁ 1.5, the light-expanding layer is made of transparent polymer resin, the material is light-cured Acrylic Resin (AR), and the refractive index n ₂ 1.5, wherein the composite adhesive layer is made of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), the refractive index is 1.5, the thickness is 1 mu m, the light filtering matrix layer is a multilayer co-extrusion polymer film, the light filtering effect is that blue light is reflected at a small incident angle (smaller than a critical angle), the reflection proportion is reduced at a large incident angle (larger than the critical angle), and the light filtering matrix layer gradually starts to transmit the blue light. The light splitting layer is designed by a biaxial standard surface: the long ribs are stacked in N directions, are tiled on the lower surface of the matrix layer, extend towards two ends infinitely, are closely arranged in the same direction, and have a topological coefficient N selected from 2, namely biaxial light splitting; the light splitting layer is selected from standard plane light splitting layers, the left and right waists of the isosceles triangle with the corresponding long rib cross section are respectively straight lines with limited interception at two ends, namely the cross section of the long rib is a straight triangle, the vertex angle theta is 90 degrees, and the bottom edge W ₁ 50 μm. The light-expanding layer is an oblique prism layer 223 and is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom side V of the triangle is 50 mu m, and the vertex angle beta is 75 degrees. The angle delta omega (i.e. omega) between the light-spreading layer and the light-splitting layer ₄ -ω ₁ ) 45 deg.. The light homogenizing film of the oblique prism has good light homogenizing performance and improves the uniformity by the range of U=469%.

Comparative example 1, examples 122 to 143

The bias compound light balancing film as provided in example 121, the other parameters are listed in table 7.

TABLE 7 design parameters and light uniformity Properties of oblique-crossing composite light homogenizing films provided in comparative example 1 and examples 121 to 143

Note that: the materials of the light-splitting layers and the light-expanding layers in comparative examples 1, 121 to 143 were AR. Bottom edge W of long rib cross section of light splitting layer ₁ Both 50 μm.

As shown in table 7, in comparative examples 1 and 121 to 123, RSD is significantly affected by the matching angle Δω, and RSD is maximum when Δω is 0 degrees, and RSD is smaller as it approaches 45 degrees, the effect of light uniformity is better, and the effect of light uniformity is poor when it deviates from 45 degrees, so that the matching angle of the oblique prism light uniformity film is preferably 30 to 60 °, and more preferably 45 °. The thickness, material and height of the prism layers of the matrix layers of comparative examples 121 and 124 to 128 have little effect on the light homogenizing performance U of the oblique prism light homogenizing film. As is clear from comparative examples 121, 129 to 133, the vertex angle of the prism layer has a significant influence on the light uniformity performance U of the oblique prism light-homogenizing film, and the smaller the vertex angle, the better the light uniformity performance, and the larger the U. As is clear from comparative examples 121, 134 to 135, the refractive index of the prism layer also has an effect on U, and the prism resin is further improved by matching with either a low refractive index or a high refractive index. As is clear from comparative examples 121, 136 to 139, the apex angle of the long rib of the spectroscopic layer also has an effect on the light uniformity, and the light uniformity is optimal at 75 degrees and the U is maximum. As is clear from comparative examples 140 to 143, when the waist of the cross-sectional triangle is curved with different degrees of radian, the light uniformity performance is slightly affected, and the convex arc side and the concave arc side have different effects on U.

It should be noted that the design principle of the composite dodging film is not limited to the design of the filter substrate layer, and the manufacturer and model of the filter substrate layer are not limited to the protection scope of the present invention. All equivalent changes and modifications made by the composite dodging film are covered in the patent scope of the invention.

Claims

1. The oblique-crossing composite light homogenizing film is characterized by comprising a light filtering substrate layer, a composite adhesive layer, a light splitting layer, a substrate layer and a light expanding layer, wherein the light splitting layer is positioned on the lower surface of the substrate layer, the composite adhesive layer is positioned on the upper surface of the light filtering substrate layer, and the tip of the light splitting layer is combined with the composite adhesive layer.

2. The oblique compound light homogenizing film of claim 1 wherein the surface finish of the light splitting layer is high and the abnormal deflection of light is small.

3. The oblique crossing composite light homogenizing film according to claim 1, wherein the material of the substrate layer is selected from one of PET, PMMA or PC; the light splitting layer is made of transparent polymer resin, and is made of photo-cured Acrylic Resin (AR) with refractive index n ₁ 1.5; the light-expanding layer is made of transparent polymer resin, and is made of photo-cured Acrylic Resin (AR) with refractive index n ₂ 1.4-1.65.

4. The oblique crossing composite dodging film according to claim 1, wherein the oblique crossing composite dodging film comprises a light filtering substrate layer, a composite adhesive layer, a light splitting layer, a substrate layer and a light spreading layer from bottom to top, the light splitting layer is positioned on the lower surface of the substrate layer, the composite adhesive layer is positioned on the upper surface of the light filtering substrate layer, and the tip of the light splitting layer is combined with the composite adhesive layer; the light splitting layer comprises N long ribs in N directions, and N is 2; the light-expanding layer is an oblique prism layer, the oblique prism layer comprises a plurality of triangular prism ribs, and the extending direction omega of the triangular prism ribs ₄ The extending direction of the long rib of the light splitting layer is omega ₁ And omega ₂ The collocation angle delta omega = omega of the triangular prism rib and the long rib direction ₄ -ω ₁ Delta omega is 30-60 degrees.

5. The oblique crossing composite light homogenizing film of claim 4 wherein the light splitting layer is one of a standard plane light splitting layer, a convex arc plane light splitting layer or a concave arc plane light splitting layer.

6. The oblique crossing composite light homogenizing film of claim 4 wherein the oblique crossing prism layer is formed by tiling triangular prism ribs, the cross section of the triangular prism ribs is isosceles triangle, the base V of the triangle is 10-100 μm, and the vertex angle beta is 60-120 °.

7. The oblique compound dodging film as claimed in claim 4, wherein the apex angle β is 75 ° and Δω is 45 °, and the light splitting layer long rib extending direction ω is the same as the light splitting layer long rib extending direction ω ₁ 0 degrees omega ₂ 90 °; the thickness of the composite adhesive layer is selected from 0.5-5 mu m, the composite adhesive layer is composed of transparent polymer resin, the material is photo-cured Acrylic Resin (AR), and the refractive index is selected from 1.45-1.55.

8. The oblique compound light homogenizing film of claim 4, wherein in the oblique compound light homogenizing film, the oblique prism layer is composed of a transparent polymer resin; the transparent polymer resin is selected from AR, refractive index n ₂ 1.4 to 1.65; the light splitting layer is formed by superposing long ribs in N directions, N is a topological coefficient, the long ribs are tiled on the lower surface of the matrix, the long ribs extend towards two ends infinitely, the long ribs in the same direction are closely arranged, the N directions equally divide 360 degrees of azimuth angles, namely, the angle intervals between the adjacent directions are 180/N degrees, and N is 2; the long ribs in the light splitting layer have the same cross section and are isosceles triangles, the left waist and the right waist are one of straight lines, convex arcs or concave arcs which are cut off at two ends in a limited way, the bottom edge is a straight line, and the bottom edge W ₁ 10-100 mu m, and the vertex angle theta is 60-120 degrees; the bending degree of the convex arc line and the concave arc line is expressed by adopting a central angle, and the central angle alpha is 1-30 degrees; the light splitting layer is one of a standard surface light splitting layer, a convex cambered surface light splitting layer or a concave cambered surface light splitting layer, and the waist of the isosceles triangle with the corresponding long rib cross section is a straight line, a convex arc line (called convex arc line for short) and a concave arc line (called concave arc line for short) which are cut out by two ends in a limited way respectively.

9. The skew compound light homogenizing film of claim 1 or 4 wherein the filter substrate layer is capable of reflecting blue light.

10. A method for preparing the oblique crossing composite dodging film according to any one of claims 1 to 9, wherein the method comprises the steps of preparing a light expansion layer by using transparent polymer resin through micro-replication or hot-press molding process on the front surface of a substrate layer; the back of the matrix layer adopts micro-replication or hot-press molding process, and the transparent polymer resin is utilized to prepare the spectroscopic layer; a coating process is adopted on the front surface of the optical filtering matrix layer, and a transparent polymer resin is utilized to prepare a composite adhesive layer which is compounded with the light splitting layer; and after the tip part of the light splitting layer is embedded into the composite adhesive layer, ultraviolet curing is carried out to combine the light filtering matrix layer with the light splitting layer.