A light-uniform film, a novel composite light-uniform film and a preparation method thereof

Abstract

The present invention relates to a composite light-uniform film, and in particular to a novel composite light-uniform film that reduces LED light shadows and improves uniformity, and a preparation method thereof. In order to improve the LED light shadow problem under high brightness, large spacing, and short light mixing distance, and to improve the uniformity of light emission, the present invention provides a novel composite light-uniform film and a preparation method thereof. The novel composite light-uniform film comprises a microlens layer, a filter base layer, a composite adhesive layer, a spectroscopic layer, and a base layer. The spectroscopic layer is located on the lower surface of the base layer, the microlens layer is located on the lower surface of the filter base layer, the composite adhesive layer is located on the upper surface of the filter base layer, and the tip of the spectroscopic layer is embedded in the composite adhesive layer so that the filter base layer is combined with the spectroscopic layer. The surface finish of the spectroscopic layer is high, and the abnormal deflection of light is small. The light-uniform film can reasonably distribute the energy concentrated within a certain range of the center of the point light source beam to other directions, and reduce the energy of the central bright spot on the projection screen and expand the overall light-emitting area, thereby improving the uniformity of energy distribution.

Description

Technical Field

[0001] The present invention relates to an optical film, in particular to a light-uniform film capable of reducing LED light shadows and improving uniformity, a novel composite light-uniform film and a preparation method thereof. Background Art

[0002] Light-emitting diodes (LEDs) are the most commonly used light sources in the field of optoelectronic displays. How to efficiently and evenly convert this point of light into the desired line light source or even surface light source has always been a topic worthy of continuous research.

[0003] In the traditional liquid crystal display (LCD) field, the display of the LCD panel requires a backlight module to provide it with light source, especially the direct backlight module. The LED array emits light with a certain beam angle vertically upward from the light board, and converts the point light source into a uniform surface light source through a diffuser plate and various traditional optical films (such as diffuser film, brightening film, etc.).

[0004] Since most of the light emitted by the LED is concentrated in the center of the beam and within a small range of beam angles deviating from the center, this highly concentrated part of the light will produce a higher light intensity (the peak light intensity of the cosine light source is at the center of the beam, and the light intensity at other angles gradually decays, and the ratio to the peak light intensity is equal to the cosine value of the angle). When projected onto the panel, a small and bright light spot will be formed directly above the lamp position - a hotspot. The energy (illuminance) distribution between the center of the hotspot and the middle of the two hotspots is quite different, resulting in lamp shadow or uneven lighting problems.

[0005] Especially in some new display technology applications, when the brightness of a single LED lamp is high, the distance between lamps is large, or the mixing distance is short, the energy distribution difference is further increased, and the shadow effect becomes more obvious. For example, in pursuit of the ultimate visual effect, MiniLED models not only design high single-lamp brightness to improve contrast and peak brightness, but also design a very short mixing distance (OD) to reduce the halo phenomenon in dark fields and reduce crosstalk between pixels, making the resolution of shadow effect more difficult. For example, large-sized conventional direct-lit models need to shorten the OD to reduce thickness, or increase the distance between lamps to reduce lamp power consumption, making the resolution of shadow effect also very difficult.

[0006] The key to solving the problem of lamp shadow is to reasonably distribute the energy concentrated within a certain range of the center of the point light source beam to other directions at a shorter mixing distance, reduce the energy of the central bright spot on the projection screen (the position of the LCD middle finger panel), expand the overall luminous area, and thus improve the uniformity of energy distribution (reduce the standard deviation).

[0007] However, due to their own optical principles, traditional diffusers and diffusers only use particle refraction, scattering, and reflection (whether air bubbles, organic particles, inorganic particles, or non-particle imprinting) to achieve disordered diffusion of light (no directionality). The expansion of the luminous area is very limited, and its energy is still concentrated in the center. Therefore, it cannot meet the light homogenization effect of the above-mentioned application scenarios (such as Figure 1 a, 1b).

[0008] Therefore, it is necessary to develop a light-uniform film (such as a light-uniform film) that can adjust the direction of light, effectively separate the light concentrated in the center (light splitting effect), and expand the luminous area (light expansion effect). Figure 1 a, 1c). Summary of the Invention

[0009] In order to improve the lamp shadow problem of a point light source array with high brightness and short OD, the present invention provides a light uniforming film and a preparation method thereof.

[0010] The light-homogenizing film provided by this invention can rationally distribute energy concentrated within a certain range at the center of a point light source's beam to other directions. This reduces the energy of the central bright spot on the projection screen and expands the overall luminous area, thereby improving the uniformity of energy distribution. The light-homogenizing film provided by this invention can also make the emitted light more uniform and the brightness more uniform, thus improving the shadow problem of high-brightness, short-OD point light source arrays.

[0011] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0012] The present invention provides a light-homogenizing film, which comprises a light-splitting layer and a base layer.

[0013] The present invention provides a light-homogenizing film, which comprises a light-splitting layer, a base layer and a light-expanding layer. The light-expanding layer is located on the upper surface of the base layer, and the light-splitting layer is located on the lower surface of the base layer.

[0014] The surface roughness of the light-splitting layer is Ra<250nm. The surface of the light-splitting layer is highly smooth.

[0015] The light uniformity film can reasonably distribute the energy concentrated within 30 degrees of the central beam angle of the point light source beam to other directions, reduce the energy of the central bright spot on the projection screen, and expand the overall luminous area, thereby improving the uniformity of energy distribution by at least 30%.

[0016] Furthermore, when the light from the light source within a beam angle of less than 30 degrees passes through the uniform light film, a single bright spot can be observed on the projection screen to be transformed into multiple bright spots or a superposition of multiple bright spots, and the bright spot size becomes smaller and the intensity becomes weaker. The uniformity of energy distribution is measured by the standard deviation of the illumination distribution on the projection screen, and the standard deviation of the illumination distribution can be increased by at least 30%.

[0017] The splitting layer is composed of long ribs stacked in N directions, where N is the topological coefficient. The long ribs are laid flat on the lower surface of the base layer, and the long ribs extend infinitely towards both ends. The long ribs in the same direction are closely arranged, and the N directions divide the 360-degree azimuth angle into equal parts, that is, the angular interval between adjacent directions is 180 / N degrees, and N is selected from 1, 2 or 3.

[0018] The cross sections of the long ribs in the light-splitting layer are the same, all are isosceles triangles, the left waist and the right waist are a straight line, a convex arc or a concave arc with finite interception at both ends, the bottom side is a straight line, the bottom side W1 is 10 to 100 μm, and the vertex angle θ is 60 to 120 o The curvature of the convex or concave arc (abbreviated as convex and concave arc) is expressed by the central angle, which is 1 to 30 degrees. o .

[0019] The spectroscopic layer is one of a standard surface spectroscopic layer, a convex arc surface spectroscopic layer and a concave arc surface spectroscopic layer, and the left and right waists of the corresponding isosceles triangle in the long rib cross section are respectively a straight line with finite interception at both ends, an outer convex arc line (referred to as a convex arc line) and an inner concave arc line (referred to as a concave arc line).

[0020] The base layer is a transparent polymer, and the material is selected from one of polyethylene terephthalate (PET), methyl methacrylate (PMMA), polycarbonate (PC), triacetyl cellulose (TAC), and cycloolefin polymer (COP).

[0021] The thickness M of the base layer is 25 to 500 μm.

[0022] The light homogenizing film is one of a plane light homogenizing film, a prism light homogenizing film, a cylindrical light homogenizing film, a pyramid light homogenizing film or a microlens light homogenizing film.

[0023] The light-homogenizing film is a planar light-homogenizing film comprising a light-splitting layer and a base layer. The light-splitting layer can be one of a standard surface light-splitting layer, a convex curved surface light-splitting layer, or a concave curved surface light-splitting layer. A light-splitting layer with a straight waist in the isosceles triangle cross-section of the long rib is called a standard surface light-splitting layer, a light-splitting layer with an outward convex curved waist is called a convex curved surface light-splitting layer, and a light-splitting layer with an inward concave curved waist is called a concave curved surface light-splitting layer.

[0024] The light-homogenizing film is a prismatic light-homogenizing film, which comprises a light-splitting layer, a base layer, and a light-expanding layer. The light-splitting layer is one of a standard surface light-splitting layer, a convex arc surface light-splitting layer, or a concave arc surface light-splitting layer. The light-expanding layer is a prismatic layer, which is formed by paving triangular prism ribs. The cross section of the triangular prism rib is an isosceles triangle, the base V of the triangle is 10 to 100 μm, and the vertex angle β is 60 to 120 o Furthermore, the vertex angle β is 75 to 105 o .

[0025] The light-diffusing film is a cylindrical light-diffusing film, which includes a light-splitting layer, a base layer, and a light-expanding layer. The light-splitting layer is one of a standard surface light-splitting layer, a convex arc surface light-splitting layer, or a concave arc surface light-splitting layer. The light-expanding layer is a cylindrical layer, which is formed by tiling cylindrical lenses. The cross-section of the cylindrical lens is a circular arc, the width (chord length) F of the arc is 20 to 1000 μm, the height of the arc is K, and the aspect ratio K / F is 0.05 to 0.5.

[0026] The light-homogenizing film is a pyramidal light-homogenizing film, which comprises a light-splitting layer, a base layer, and a light-expanding layer. The light-splitting layer is one of a standard surface light-splitting layer, a convex arc surface light-splitting layer, or a concave arc surface light-splitting layer. The light-expanding layer is a pyramidal layer, which is formed by tiling triangular pyramids or quadrangular pyramids. The vertices of the triangular pyramids form a regular triangle arrangement, and the vertices of the quadrangular pyramids form a square arrangement. The height T of the pyramid is 10 to 100 μm, and the angle γ between the side and the height is 30 to 60. o ;

[0027] The light-homogenizing film is a microlens light-homogenizing film, and the microlens light-homogenizing film includes a light-splitting layer, a base layer, and a light-expanding layer. The light-splitting layer is one of a standard surface light-splitting layer, a convex arc surface light-splitting layer, or a concave arc surface light-splitting layer. The light-expanding layer is a microlens layer, in which the coordinates of the main optical axes of three adjacent microlenses are connected to form an equilateral triangle array, and the microlenses in the microlens array are closely arranged. The width G of the microlens is 10 to 100 μm, the height of the microlens is H, the aspect ratio H / G is 0.05 to 0.5, and the spacing D between the main optical axes of adjacent microlenses is equal to G.

[0028] The light splitting layer and the light expanding layer are made of transparent polymer resin.

[0029] The transparent polymer resin is made of one of AR (Acrylic resin or modified acrylic resin), PMMA or PC. AR is preferably made by a photocuring process, while PMMA and PC are preferably made by a hot pressing process.

[0030] The transparent polymer resin of the light-splitting layer is selected from one of AR, PC or PMMA, and the refractive index n1 is selected from 1.4 to 1.65.

[0031] When the light expansion layer is a prism layer, a cylindrical lens layer, a pyramid layer, or a microlens layer, the transparent polymer resin is selected from one of AR, PC, or PMMA, and the refractive index n2 is selected from 1.4 to 1.65.

[0032] The present invention provides a light-homogenizing film, comprising a base layer 20 and a light-splitting layer 21, and a light-expanding layer 22 does not exist. Figure 10As shown, the homogenizing film is a planar homogenizing film. The thickness M of the base layer 20 is 25-500μm, for example, 25μm, 75μm, 100μm, 125μm, 250μm, 500μm, and the material of the base layer is selected from one of PET, PMMA or PC. The splitting layer is composed of a transparent polymer resin, and the material is one of photocurable acrylic resin (AR), PMMA or PC, and the refractive index n1 is 1.4-1.65, for example, 1.4, 1.5, 1.58, 1.65. The splitting layer is a uniaxial standard surface design: it is composed of long ribs in N directions superimposed, and the long ribs are flat on the lower surface of the base layer. The long ribs extend infinitely toward both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is 1, that is, uniaxial splitting (such as Figure 6 The spectroscopic layer is selected from the standard surface spectroscopic layer, and the corresponding long rib cross section is an isosceles triangle with left and right waists respectively as the straight lines intercepted at both ends, that is, the cross section of the long rib is an isosceles triangle with a vertex angle θ of 60 o -120 o , for example 60 o , 75 o , 80 o , 90 o , 105 o , 120 o When the light splitting layer is a convex arc light splitting layer or a concave arc light splitting layer, the left and right waists of the corresponding long rib cross section isosceles triangle are the convex arc line (referred to as convex arc line) and the concave arc line (referred to as concave arc line) with finite interception at both ends, and the vertex angle θ is 60 o -120 o , such as 60o, 80 o , 87 o , 90 o , 100 o , 120 o , the central angle α is 1-30 o , for example 1 o , 3 o , 10 o , 30 o The uniformity film has good uniformity performance, with a uniformity improvement range of U=30-120%. The above technical solution includes embodiments 1-31.

[0033] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 11As shown, the homogenizing film is a prism homogenizing film. The thickness M of the base layer 20 is 25-500μm, for example, 25μm, 75μm, 250μm, 500μm, the material of the base layer is selected from one of PET, PMMA or PC, the splitting layer is composed of a transparent polymer resin, the material is a photocurable acrylic resin (AR), and the refractive index n1 is 1.5, the light expanding layer is composed of a transparent polymer resin, the material is a photocurable acrylic resin (AR), and the refractive index n2 is 1.4-1.65, for example, 1.4, 1.5, 1.65. The splitting layer is a biaxial standard surface design: it is composed of long ribs in N directions superimposed, the long ribs are flat on the lower surface of the base layer, the long ribs extend infinitely toward both ends, the long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, that is, biaxial splitting (such as Figure 7 The spectroscopic layer is selected from the standard surface spectroscopic layer, and the corresponding long rib cross section is an isosceles triangle with the left and right waists being the straight lines intercepted by the two ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o The light expansion layer is a prism layer 221, which is made of triangular prism ribs. The cross section of the triangular prism rib is an isosceles triangle. The base V of the triangle is 10-100μm, such as 10μm, 25μm, 50μm, 75μm, 100μm, and the vertex angle β is 60 o -120 o , for example 60 o , 75 o , 90 o , 105 o , 120 o The uniformity film has good uniformity performance, with a uniformity improvement range of U=91-302%. The above technical solution includes embodiments 37-48.

[0034] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 12As shown, the light-homogenizing film is a cylindrical light-homogenizing film. The thickness M of the base layer 20 is 25-500 μm, for example, 25 μm, 75 μm, 125 μm, 250 μm, or 500 μm. The base layer is made of a material selected from PET, PMMA, or PC. The light-splitting layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n1 of 1.5. The light-expanding layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n2 of 1.4-1.65, for example, 1.4, 1.5, or 1.65. The light splitting layer is designed as a biaxial standard surface: it is composed of long ribs in N directions, which are laid flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is selected from 2, that is, biaxial light splitting; the light splitting layer is selected from the standard surface light splitting layer, and the left and right sides of the corresponding long rib cross section are isosceles triangles with finite intercepts at both ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o The light expansion layer is a cylindrical lens layer 222, which is formed by laying cylindrical lens ribs flat. The cross section of the cylindrical lens is an arc. The width (chord length) F of the arc is 20-1000μm, for example, 20μm, 50μm, 100μm, 250μm, 500μm, 1000μm, the height of the arc is K, and the aspect ratio K / F is 0.05-0.5, for example, 0.05, 0.1, 0.3, 0.5. The uniform light film has good uniformity performance, and the uniformity improvement range U = 97-125%. The above technical solution includes embodiments 49-60.

[0035] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 13 As shown, the light-homogenizing film is a pyramidal light-homogenizing film. The thickness M of the base layer 20 is 25-500 μm, for example, 25 μm, 75 μm, 250 μm, or 500 μm. The base layer is made of a material selected from PET, PMMA, or PC. The light-splitting layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n1 of 1.5. The light-diffusing layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n2 of 1.4-1.65, for example, 1.4, 1.5, or 1.65. The light splitting layer is designed as a biaxial standard surface: it is composed of long ribs in N directions, which are laid flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is selected from 2, that is, biaxial light splitting; the light splitting layer is selected from the standard surface light splitting layer, and the left and right sides of the corresponding long rib cross section are isosceles triangles with finite intercepts at both ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 oThe light diffusion layer is a quadrangular pyramid layer 224, which is made of quadrangular pyramids. The vertices of the quadrangular pyramids are arranged in a square. The height T of the pyramid is 10-50 μm, for example, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, and the angle γ between the side and the height is 30 o -60 o , for example 30 o , 45 o , 60 o The uniform light film has good uniform light performance, with a uniformity improvement range of U=41-270%. The above technical solution includes embodiments 61-70.

[0036] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 14 As shown, the light-homogenizing film is a microlens light-homogenizing film. The thickness M of the base layer 20 is 25-500 μm, for example, 25 μm, 75 μm, 250 μm, or 500 μm. The base layer is made of a material selected from PET, PMMA, or PC. The light-splitting layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n1 of 1.5. The light-diffusing layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n2 of 1.4-1.65, for example, 1.4, 1.5, or 1.65. The light splitting layer is designed as a biaxial standard surface: it is composed of long ribs in N directions, which are laid flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is selected from 2, that is, biaxial light splitting; the light splitting layer is selected from the standard surface light splitting layer, and the left and right sides of the corresponding long rib cross section are isosceles triangles with finite intercepts at both ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o . The light expansion layer is a microlens layer 225, and the coordinates of the main optical axes of three adjacent microlenses are connected to form an equilateral triangle array, and the microlenses in the microlens array are closely arranged. The width G of the microlens is 10-100μm, for example, 10μm, 25μm, 50μm, 75μm, 100μm, the height of the microlens is H, and the aspect ratio H / G is 0.05-0.5, for example, 0.05, 0.1, 0.3, 0.5, and the spacing D between the main optical axes of adjacent microlenses is equal to G. The light-uniforming film has good light-uniforming performance, and the uniformity improvement range U = 97-114%. The aforementioned technical solution includes embodiments 71-80.

[0037] The present invention provides a method for preparing a light-uniform film, which is characterized in that a micro-replication or hot pressing process is adopted on the back of the base layer to prepare a light-splitting layer using a transparent polymer resin, and a light-curing micro-replication or hot pressing process is adopted on the front of the base layer to prepare a light-expanding layer using a transparent polymer resin formula.

[0038] Furthermore, the preparation method of the light-homogenizing film includes the following steps:

[0039] (1) The substrate layer is used as a supporting layer, and a light-splitting layer is prepared on the back side to obtain a planar light-homogenizing film containing only the light-splitting layer and the substrate layer;

[0040] Furthermore, the preparation method of the light-homogenizing film includes the following steps:

[0041] (1) preparing a mold 1 for a light-splitting layer;

[0042] (2) Using the base layer as a support layer, the light-splitting layer is micro-replicated or hot-pressed on the back side using the mold 1 to obtain a light-splitting film containing only the light-splitting layer and the base layer (i.e., a flat light-splitting film, which can also be used as a light-splitting film semi-finished product with other light-spreading layer structures);

[0043] Furthermore, the preparation method of the light-homogenizing film includes the following steps:

[0044] (1) The substrate layer is used as a support layer, and a splitter layer is prepared on the back side to obtain a semi-finished product containing the splitter layer;

[0045] (2) preparing a light expansion layer on the front side of the semi-finished product obtained in step (1) to obtain a light-uniform film containing both a light-splitting layer and a light-expanding layer;

[0046] Furthermore, the preparation method of the light-homogenizing film includes the following steps:

[0047] (1) A mold 1 (with concave long ribs and superimposed texture) for preparing the light-splitting layer is generally made from a polished metal roller or metal plate through a diamond engraving process, wherein the shape of the diamond engraving tool is the same as the cross section of the long ribs;

[0048] (2) using the mold 1 to micro-copy or hot press mold a light-splitting layer (with convex long ribs and superimposed texture) on the back of the base layer to obtain a semi-finished product containing the light-splitting layer;

[0049] (3) preparing a mold 2 for the light expansion layer (complementary structure of the light expansion layer), which is generally made of a polished metal roller or metal plate through processes such as micro-bead blasting and diamond carving;

[0050] (4) using mold 2 to micro-replicate or hot-press the light-expanding layer on the front surface of the base layer to obtain a light-uniform film containing both the light-splitting layer and the light-expanding layer;

[0051] Furthermore, the preparation method of the light-homogenizing film includes the following steps:

[0052] (1) A mold 1 (with concave long ribs and superimposed texture) for preparing the light-splitting layer is generally made from a polished metal roller or metal plate through a diamond engraving process, wherein the shape of the diamond engraving tool is the same as the cross section of the long ribs;

[0053] (2) using the mold 1 to micro-copy or hot press mold a light-splitting layer (with convex long ribs and superimposed texture) on the back of the base layer to obtain a semi-finished product containing the light-splitting layer;

[0054] (3) A mold 2 for preparing the light expansion layer (the light expansion layer has the same structure), which is generally made of a polished metal roller or metal plate through processes such as micro-bead blasting and diamond carving;

[0055] (4) preparing a mold 3 for the light expansion layer (complementary structure of the light expansion layer), which can be obtained by stamping the mold 2 (by extruding a low-hardness metal with a high-hardness metal), or by electroforming a metal mold with a complementary structure using an optical film with the same structure as the light expansion layer as a template, or by stamping the optical film with a complementary structure obtained by stamping the mold 2 and directly using it as a soft mold 3;

[0056] (5) Using mold 3 to micro-replicate or hot-press the light-expanding layer on the front side of the base layer, a light-uniform film containing both the light-splitting layer and the light-expanding layer is obtained;

[0057] It should be noted that the processing method of the light splitting layer and the light expansion layer should be selected according to the structure type and material type, and the present invention does not make a preference.

[0058] It should be noted that the method for preparing the light-homogenizing film provided by the present invention is applicable to the production of sheets as well as the production of coils.

[0059] This light-uniform film can be used as an optically functional material in direct-lit LED array backlight systems. It's particularly well-suited for Mini LED backlights, where it can improve shadowing in arrays of high-brightness, short-OD (OD) point light sources. OD represents the distance from a point light source to the closest optical film sheet in the backlight architecture. Short OD can mean an OD of less than 1mm, or even zero.

[0060] Compared with the existing technology, the uniform light film provided by the present invention can reasonably distribute the energy concentrated in the center of the point light source beam, especially within a beam angle of 30 degrees, to other directions, and reduce the energy of the central bright spot on the projection screen and expand the overall luminous area, thereby improving the uniformity of energy distribution by at least 30%.

[0061] In some larger Mini LED backlight applications (such as TVs and monitors), the distance between the lamps is larger (generally greater than 5mm). In order to achieve an ultra-thin design with short or even zero OD at this large lamp spacing, a uniform light film product with better uniform light effect is required, even if it means sacrificing some brightness to further improve the uniform light effect.

[0062] Through a base film with filtering function (filter matrix layer), blue light can be selectively reflected, so that the blue light is mixed multiple times between the lamp and the filter matrix layer, that is, reflected back and forth multiple times (such as Figure 15 As shown), thereby indirectly increasing the light propagation distance (as shown Figure 16 As shown in the figure, the OD (light mixing distance) is increased, which can effectively improve the light uniformity effect.

[0063] The filter matrix layer reflects blue light at a small incident angle, and at a large incident angle, the reflection ratio decreases and begins to transmit blue light (this is generally the case for filters based on the principle of multilayer films. The spectrum is correlated with the incident angle, such as Figure 17a Therefore, the main principle of multiple light mixing is as follows: Figure 15 As shown, the lower surface of the filter matrix layer undergoes mirror reflection without changing the direction, while diffuse reflection occurs at the reflective surface of the light board and changes the direction, causing the incident angle to gradually increase and ultimately the transmission ratio to become higher and higher.

[0064] The present invention provides a composite light-homogenizing film, which comprises a filter base layer, a composite adhesive layer, a splitting layer, and a base layer. The splitting layer is located on the lower surface of the base layer, the composite adhesive layer is located on the upper surface of the filter base layer, and the tip of the splitting layer is combined with the composite adhesive layer.

[0065] The light-splitting layer is one of a standard surface light-splitting layer, a convex arc surface light-splitting layer and a concave arc surface light-splitting layer.

[0066] The surface of the spectroscopic layer is highly smooth and there is little abnormal deflection of light.

[0067] Furthermore, the filter matrix layer is a multi-layer co-extruded polymer film, and the filtering effect is to reflect blue light at a smaller incident angle (less than the critical angle), and the reflection ratio decreases at a larger incident angle (greater than the critical angle), and gradually begins to transmit blue light.

[0068] Furthermore, the multi-layer co-extruded polymer film is composed of alternating layers of high / low refractive index polymers. The refractive index and thickness of each layer are not limited, but must meet the above-mentioned filtering effect.

[0069] Furthermore, the spectral characteristics of the filter substrate layer, such as the reflection band, reflectivity and critical angle, are not limited. As long as the reflection band can cover the wavelength range of the blue light source, the uniform light effect of the present invention can be achieved.

[0070] Furthermore, the thickness of the filter matrix layer is not limited, and the number of layers and the thickness of each layer are ultimately determined by the spectral characteristics, thereby determining the total thickness.

[0071] Furthermore, the thickness of the composite adhesive layer is selected from 0.5 to 5 μm.

[0072] Furthermore, the composite adhesive layer is made of a transparent polymer resin, the material of which is a light-cured acrylic resin (AR), and the refractive index n3 is selected from 1.45 to 1.55.

[0073] The present invention provides a composite light-homogenizing film, which comprises, from top to bottom, a base layer, a spectroscopic layer, a composite adhesive layer, and a filter base layer, wherein the base layer and the spectroscopic layer constitute a planar light-homogenizing film, that is, the composite light-homogenizing film can also be understood as consisting of a planar light-homogenizing film, a composite adhesive layer, and a filter base layer. The thickness M of the base 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 base layer is selected from one of PET, PMMA, or PC; the spectroscopic layer is composed of a transparent polymer resin, and the material is one of a light-cured acrylic resin (AR), PMMA, or PC, and the refractive index n1 is 1.4-1.65, for example, 1.4, 1.5, 1.58, or 1.65; the The composite adhesive layer is made of a transparent polymer resin, and the material is also a light-cured acrylic resin (AR), with a refractive index of 1.45-1.55, for example, 1.45, 1.5 or 1.55, and a thickness of 0.5-5μm, for example, 0.5μm, 1μm or 5μm; the filter base layer is a multi-layer co-extruded polymer film, and the filter effect is to reflect blue light at a smaller incident angle (less than the critical angle), and the reflection ratio decreases at a larger incident angle (greater than the critical angle), and gradually begins to transmit blue light. The spectroscopic layer is composed of long ribs in N directions, and the long ribs are flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged, and the topological coefficient N is 1, 2 or 3; the spectroscopic layer is selected from one of a standard surface spectroscopic layer, a convex arc surface spectroscopic layer or a concave arc surface spectroscopic layer. The cross-section of the long ribs corresponding to the standard surface spectroscopic layer is an isosceles triangle with the left and right legs being finitely intercepted straight lines at both ends, that is, the cross-section of the long ribs is a right-sided triangle with a vertex angle θ of 60 o -120 o , for example 60 o , 75 o , 90 o , 105 o , or 120 o When the light splitting layer is a convex arc light splitting layer, the vertex angle θ is 91 o -120 o , for example 91 o , 93 o , 100 o , or 120 o , the central angle α is 1-30 o , for example 1 o , 3 o , 10 o , or 30 o When the light splitting layer is a concave arc light splitting layer, the vertex angle θ is 60 o -89 o , for example 60 o , 80 o , 87 o， , or 89o , the central angle α is 1-30 o , for example 1 o , 3 o , 10 o , or 30 o The uniformity film has good uniformity performance, with a uniformity improvement range U of 160-397%. The above technical solution includes embodiments 81-120.

[0074] The present invention provides a method for preparing a composite light-homogenizing film, wherein a micro-replication or hot pressing process is adopted on the back of a base layer to prepare a plurality of light-splitting layers using a transparent polymer resin; a coating process is adopted on the front of a light-filtering base layer to prepare a composite adhesive layer using a transparent polymer resin, and the composite adhesive layer is composited with the light-splitting layer; after the tip of the light-splitting layer is embedded in the composite adhesive layer, ultraviolet curing is performed to firmly bond the light-filtering base layer to the composite adhesive layer.

[0075] Furthermore, the preparation method of the composite light-homogenizing film includes the following steps:

[0076] (1) A mold 1 (with concave long ribs and superimposed texture) for preparing the light-splitting layer is generally made from a polished metal roller or metal plate through a diamond engraving process, wherein the shape of the diamond engraving tool is the same as the cross section of the long ribs;

[0077] (2) using the mold 1 to micro-copy or hot press mold a light-splitting layer (with convex long ribs and superimposed texture) on the back of the base layer to obtain a semi-finished product containing the light-splitting layer;

[0078] (3) unwinding the filter substrate layer at the first unwinding station and coating the composite adhesive layer (uncured) on the front surface thereof to obtain a semi-finished product containing the composite adhesive layer, and unwinding the semi-finished spectrometer layer at the second unwinding station;

[0079] (4) The two rolls of semi-finished products are stacked and compounded by tension or pressure, so that the tip of the splitting layer is embedded in the composite adhesive layer, and the composite adhesive layer is quickly cured by ultraviolet curing equipment so that it is firmly bonded to the tip of the splitting layer;

[0080] (5) Winding at the first winding station to obtain a finished composite uniform film;

[0081] This composite light-homogenizing film can be used as an optically functional material in direct-lit LED array backlight systems. It is particularly suitable for larger Mini LED backlight applications (such as TVs and monitors), improving the shadowing problem of large-pitch, high-brightness, and short-OD point light source arrays.

[0082] Compared with the existing technology, the composite light-homogenizing film provided by the present invention can reasonably distribute the energy concentrated in the center of the point light source beam, especially within a beam angle of 30 degrees, to other directions, and reduce the energy of the central bright spot on the projection screen and expand the overall luminous area, thereby improving the uniformity of energy distribution by at least 160%.

[0083] In the subsequent research process, we found that when the beam angle of the original light source is relatively large, there is a portion of light with a large incident angle (greater than the critical angle) on the filter matrix layer. The lens structure can converge it, causing most of the light to be deflected in the vertical direction (less than the critical angle). Figure 19a 、 19b As shown in Figure 19b (19a without the normal angle mark), when the lens size is large, assuming the critical angle is 30 degrees, then the 45-degree light emitted from the light source directly below the lens will not be reflected when it enters the filter matrix layer, while the 15-degree light will be reflected. After adding a lens structure (refractive index 1.5), the 45-degree light will be deflected to near 11 degrees and the 15-degree light will be deflected to near 8 degrees, so both will be reflected. Figure 19c As shown in the figure, when the lens size is small, the light emitted by the light source can be equivalent to parallel light at different angles. Taking light with incident angles of 60 degrees (a1-a4), 30 degrees (b1-b4), and 0 degrees (c1-c4) as representative analysis, it can be seen that most of the light passes through the lens at a small incident angle and is reflected (for clarity, the reflected light is not shown), with only two points of light passing through. In summary, the microlens structure's increased reflection ratio helps improve the uniform light effect.

[0084] The present invention provides a novel composite light-homogenizing film, which comprises, from bottom to top, a microlens layer, a filter base layer, a composite adhesive layer, a beam splitter layer, and a base layer. The beam splitter layer is located on the lower surface of the base layer, the microlens layer is located on the lower surface of the filter base layer, and the composite adhesive layer is located on the upper surface of the filter base layer. The tip of the beam splitter layer is embedded in the composite adhesive layer, bonding the filter base layer to the composite adhesive layer.

[0085] The splitting layer is composed of long ribs stacked in N directions, where N is the topological coefficient. The long ribs are laid flat on the lower surface of the base layer, and the long ribs extend infinitely towards both ends. The long ribs in the same direction are closely arranged, and the N directions divide the 360-degree azimuth angle into equal parts, that is, the angular interval between adjacent directions is 180 / N degrees, and N is selected from 1, 2 or 3.

[0086] The cross sections of the long ribs in the light-splitting layer are the same, all are isosceles triangles, the left waist and the right waist are a straight line, a convex arc or a concave arc with finite interception at both ends, the bottom side is a straight line, the bottom side W1 is 10 to 100 μm, and the vertex angle θ is 60 to 120 oThe curvature of the convex or concave arc (abbreviated as convex and concave arc) is expressed by the central angle, which is 1 to 30 degrees. o .

[0087] The light-splitting layer is one of a standard surface light-splitting layer, a convex arc surface light-splitting layer and a concave arc surface light-splitting layer.

[0088] The surface of the light splitting layer is highly smooth and has little abnormal deflection of light. Furthermore, the surface roughness of the light splitting layer is Ra < 250 nm.

[0089] Furthermore, the filter matrix layer is capable of reflecting blue light.

[0090] Furthermore, the filter matrix layer is a multi-layer co-extruded polymer film, and the filtering effect is to reflect blue light at a smaller incident angle (less than the critical angle), and the reflection ratio decreases at a larger incident angle (greater than the critical angle), and gradually begins to transmit blue light.

[0091] Furthermore, the multi-layer co-extruded polymer film is composed of alternating layers of high-refractive-index polymers and low-refractive-index polymers. The refractive index and thickness of each layer are not limited, but must meet the above-mentioned light filtering effect.

[0092] Furthermore, the spectral characteristics of the filter substrate layer, such as the reflection band, reflectivity and critical angle, are not limited. As long as the reflection band can cover the wavelength range of the blue light source, the uniform light effect of the present invention can be achieved.

[0093] Furthermore, the thickness of the filter matrix layer is not limited, and the number of layers and the thickness of each layer are ultimately determined by the spectral characteristics, thereby determining the total thickness.

[0094] Furthermore, the thickness of the composite adhesive layer is selected from 0.5 to 5 μm.

[0095] Furthermore, the composite adhesive layer is made of a transparent polymer resin, the material of which is a light-cured acrylic resin (AR), and the refractive index is selected from 1.45 to 1.55.

[0096] Furthermore, the thickness M2 of the microlens layer is selected from 25 to 500 μm.

[0097] In the microlens layer, the coordinates of the principal optical axes of three adjacent microlenses are connected to form an equilateral triangle array. The microlenses in the microlens array are closely arranged. The width G2 of the microlenses is 10 to 100 μm, the height of the microlenses is H2, the aspect ratio H2 / G2 is 0.1 to 0.5, and the spacing D2 between the principal optical axes of adjacent microlenses is equal to G2.

[0098] Furthermore, the microlens layer is made of a transparent polymer resin, the material of which is a light-cured acrylic resin (AR), and the refractive index is selected from 1.4 to 1.6.

[0099] The present invention provides a novel composite light-homogenizing film, which comprises a base layer 20, a light-splitting layer 21, a composite adhesive layer 24, a filter base layer 23 and a microlens layer 27 in order from top to bottom. Figure 20 As shown, the base layer 20 and the light-splitting layer 21 form a planar light-homogenizing film, that is, the novel composite light-homogenizing film can also be understood to be composed of a planar light-homogenizing film, a composite adhesive layer, a filter base layer and a microlens layer. The base layer has a thickness M of 25-500 μm, for example, 25 μm, 75 μm, 100 μm, 125 μm, 250 μm, or 500 μm, and is made of a material selected from PET, PMMA, or PC. The spectroscopic layer is composed of a transparent polymer resin, such as a photocurable acrylic resin (AR), PMMA, or PC, and has a refractive index n1 of 1.4-1.65, such as 1.4, 1.5, 1.58, or 1.65. The composite adhesive layer is composed of a transparent polymer resin, also made of a photocurable acrylic resin (AR), with a refractive index of 1.5 and a thickness of 1 μm. The filter base layer is a multi-layer co-extruded polymer film, and has a filtering effect of reflecting blue light at smaller incident angles (less than a critical angle), decreasing the reflection ratio at larger incident angles (greater than the critical angle), and gradually beginning to transmit blue light. The coordinates of the principal optical axes of three adjacent microlenses in the microlens layer are connected to form an equilateral triangle array, and the microlenses in the microlens array are closely arranged. The width G2 of the microlens is 10-100 μm, for example, 10 μm, 25 μm, 50 μm, 75 μm, or 100 μm. The height of the microlens is H2, and the aspect ratio H2 / G2 is 0.1-0.5, for example, 0.1, 0.3, or 0.5. The spacing D2 between the principal optical axes of adjacent microlenses is equal to G2. The material of the microlens layer is a light-curable acrylic resin (AR), and the refractive index n3 is 1.4-1.6, for example, 1.4, 1.5, or 1.6. The light-splitting layer is composed of long ribs in N directions, which are laid flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is 1, 2 or 3. The light-splitting layer is selected from one of the standard surface light-splitting layer, the convex arc surface light-splitting layer or the concave arc surface light-splitting layer. The cross section of the long rib corresponding to the standard surface light-splitting layer is an isosceles triangle with the left and right waists being the straight lines intercepted by the two ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 60. o -120 o , for example 60 o , 75 o , 90 o , 105 o , or 120 o When the light splitting layer is a convex arc light splitting layer, the vertex angle θ is 91 o -120 o , for example 91 o , 93 o, 100 o , or 120 o , the central angle α is 1-30 o , for example 1 o , 3 o , 10 o , or 30 o When the light splitting layer is a concave arc light splitting layer, the vertex angle θ is 60 o -89 o , for example 60 o , 80 o , 87 o， , or 89 o , the central angle α is 1-30 o , for example 1 o , 3 o , 10 o , or 30 o The uniformity film has good uniformity performance, with a uniformity improvement range of U=211-429%. The above technical solution includes embodiments 121-168.

[0100] The present invention provides a method for preparing a novel composite light-homogenizing film. The method comprises the following steps: a micro-replication or hot pressing process is adopted on the back of a base layer to prepare a plurality of light-splitting layers using a transparent polymer resin; a micro-replication process is adopted on the back of a light-filtering base layer to prepare a microlens layer using a transparent polymer resin; a coating process is adopted on the front of the light-filtering base layer to prepare a composite adhesive layer using a transparent polymer resin, and the composite adhesive layer is composited with the light-splitting layer; and after the tip of the light-splitting layer is embedded in the composite adhesive layer, ultraviolet curing is performed to firmly bond the light-filtering base layer to the composite adhesive layer.

[0101] Furthermore, the preparation method of the novel composite light-homogenizing film comprises the following steps:

[0102] (1) A mold 1 (with concave long ribs and superimposed texture) for preparing the light-splitting layer is generally made from a polished metal roller or metal plate through a diamond engraving process, wherein the shape of the diamond engraving tool is the same as the cross section of the long ribs;

[0103] (2) using the mold 1 to micro-copy or hot press mold a light-splitting layer (with convex long ribs and superimposed texture) on the back of the base layer to obtain a semi-finished product containing the light-splitting layer;

[0104] (3) preparing a mold 2 (concave microlens structure) for the microlens layer, which is generally made by laser engraving or diamond engraving on a polished metal roller. The concave microlens structure texture is transferred to a transparent substrate (which can be a polymer film or a glass substrate) through a double transfer process (concave to convex, convex to concave) using a transparent resin to prepare a transparent mold 3 (concave microlens structure);

[0105] (4) Using the transparent mold 3, a microlens layer is micro-replicated on the back of the filter substrate layer to obtain a semi-finished filter substrate layer-1.

[0106] (5) unwinding the filter substrate layer semi-finished product-1 at the first unwinding station, and coating the composite adhesive layer (uncured) on the front thereof to obtain a semi-finished product-2 containing the composite adhesive layer, and unwinding the spectrometer layer semi-finished product at the second unwinding station;

[0107] (6) The two rolls of semi-finished products are stacked and compounded by tension or pressure, so that the tip of the splitting layer is embedded in the composite adhesive layer, and the composite adhesive layer is quickly cured by ultraviolet curing equipment so that it is firmly bonded to the tip of the splitting layer;

[0108] (6) Winding at the first winding station to obtain a new composite uniform light film product;

[0109] This new composite light-homogenizing film can be used as an optically functional material in direct-lit LED array backlight systems. It is particularly suitable for larger Mini LED backlight applications (such as TVs and monitors), improving the shadowing problem of large-pitch, high-brightness, and short-OD point light arrays.

[0110] Compared with the existing technology, the new composite light-homogenizing film provided by the present invention can reasonably distribute the energy concentrated in the center of the point light source beam, especially within a beam angle of 30 degrees, to other directions, and reduce the energy of the central bright spot on the projection screen and expand the overall luminous area, thereby improving the uniformity of energy distribution by at least 211%. BRIEF DESCRIPTION OF THE DRAWINGS

[0111] Figure 1 Comparison of typical light uniformity effects of diffuser / diffusion film (a: light source, b: light source + diffuser film, c: light source + diffuser film);

[0112] Figure 2 Schematic diagram of the light-homogenizing film performance evaluation framework;

[0113] Figure 3 shows the method for evaluating the light-dispersing effect of a homogenizing film (a spherical coordinate system, b Lambertian light source, c Lambertian light source + homogenizing film);

[0114] Figure 4 The composition and cross-sectional diagram of the light-homogenizing film (a: substrate layer + light-splitting layer, b: substrate layer + light-splitting layer + light-diffusing layer);

[0115] Figure 5 Schematic diagram of the principle of light splitting (a) and light expansion (b);

[0116] Figure 6 Design principle of the long rib stacking (N=1) in the light splitting layer (a) long rib stacking method, b) light splitting structure details, c) light splitting effect, d) magnified details of the light splitting effect;

[0117] Figure 7Design principle of the long rib stacking (N=2) in the light splitting layer (a) long rib stacking method, b) light splitting structure details, c) light splitting effect, d) magnified details of the light splitting effect;

[0118] Figure 8 Design principle of the long rib stacking (N=3) in the light splitting layer (a) long rib stacking method, b) light splitting structure details, c) light splitting effect, d) magnified details of the light splitting effect;

[0119] Figure 9 Schematic diagrams of long ribs of different shapes and their cross sections (a three stereoscopic views, b cross section convex arc-edged triangle, c cross section straight-edged triangle, d cross section concave arc-edged triangle);

[0120] Figure 10 Schematic diagram of the three-dimensional structure of the flat light-homogenizing film;

[0121] Figure 11 Schematic diagram of the three-dimensional structure of the prism light-homogenizing film and the cross-section of the prism ribs;

[0122] Figure 12 Schematic diagram of the three-dimensional structure of the cylindrical light-homogenizing film and the cross-section of the cylindrical lens;

[0123] Figure 13 Schematic diagram of the three-dimensional structure of the pyramid light-homogenizing film and the four-sided pyramid structure;

[0124] Figure 14 Schematic diagram of the three-dimensional structure of the microlens light-homogenizing film and the microlens structure;

[0125] Figure 15 The diagram shows the principle of the filter matrix layer reflecting light incident at a small angle and transmitting light incident at a large angle;

[0126] Figure 16 This is a schematic diagram of the equivalent increase in OD value due to multiple reflections of light (specular reflection from the filter substrate layer and diffuse reflection from the light panel);

[0127] Figure 17a is the visible light transmittance spectrum of the filter substrate layer at different angles of incidence (AOI);

[0128] Figure 17b (b) is the blue light reflectivity spectrum of the filter substrate layer at different angles of incidence (AOI);

[0129] Figure 18 Schematic diagram of the composition and cross section of the composite light-homogenizing film;

[0130] FIG19 is a schematic diagram showing the principle of a microlens deflecting light at a large angle into a small angle;

[0131] Figure 20 Schematic diagram of the composition and cross section of the new composite light-homogenizing film.

[0132] picture

[0133] in:

[0134] 0: LED light board; 1: LED; 00: LED light board; 01: LED; 2: uniform light film; 3: absorption screen;

[0135] 20: substrate layer; 21: light splitting layer; 22: light expansion layer; 23: filter substrate layer; 24: composite adhesive layer; 27: microlens layer;

[0136] 40: Input light; 411: Penetrating light; 412: Recycled light; 42: Output light; 43: Secondary input light; 44: Light emitted from a light source at a small angle; 45: Light emitted from a light source at a large angle;

[0137] 50: ridge of long ribs / short ribs; 51: valley between long ribs / short ribs;

[0138] 221: Prism structure; 222: Cylindrical structure; 224: Pyramid structure; 225: Microlens structure. DETAILED DESCRIPTION

[0139] In order to make it easier to understand the structure of the present invention and the functional features and advantages that can be achieved, the preferred embodiments of the present invention are described in detail below with reference to the drawings.

[0140] The present invention provides a light-uniform film, wherein the light-splitting layer of the light-uniform film plays a light-splitting role, and the light-expanding layer plays a major light-expanding role. If there is no light-expanding layer, the base layer can play a certain light-expanding role. The main principle is as follows: Figure 5 shown.

[0141] Taking the plane light-homogenizing film as an example, since the main light of the light source is concentrated in the normal direction, Figure 5 Figure a shows the spectroscopic process that occurs when the normal input light 40 is incident on the spectroscopic layer 21. The light is incident through the inclined outer surfaces on both sides of the spectroscopic layer, resulting in at least two directions of deflection (the number varies depending on the structure of the spectroscopic layer, if the tetrahedron is actually four directions), and the generated incident light 411 is transmitted inside the uniform light film, and is emitted from the upper surface of the base layer 20, and is deflected again (light dense to light sparse), generating further separated output light 42. This is the basic principle of the spectroscopic process. A beam of light from a point light source is dispersed after passing through the spectroscopic layer, and the light beams of several point light sources are dispersed by the spectroscopic layer. The dispersed light rays are superimposed on each other, making the output light more uniform.

[0142] Taking the plane light-homogenizing film as an example, a small amount of large-angle light is incident obliquely on the light-splitting layer. Figure 5b shows the light expansion process that occurs after the input light 40 at 45 degrees is incident on the spectroscopic layer 21. Taking the light on the right as an example, the light is incident to the right through the inclined outer surface of the spectroscopic layer and is transmitted to the upper surface of the base layer. Since the angle meets the critical angle of total reflection, total reflection occurs, generating recycled light 412. This part of the light passes through the spectroscopic layer and will be diffusely reflected at the bottom light panel, generating upward secondary input light 43. When this part of the light reaches the spectroscopic layer again, it has a considerable horizontal distance from the position of the initial input light 40. Or it can be understood that this repeated light cycle up and down indirectly expands the vertical light mixing distance. In short, this process ultimately allows light energy to be distributed to a larger area. This is the basic principle of the light expansion process.

[0143] Although a single flat light-homogenizing film mainly splits the light and has a smaller light expansion effect, when multiple light-homogenizing films are stacked, the input light of the upper light-homogenizing film is tilted, which can increase the proportion of light expansion.

[0144] In general, in order for the actual optical path to conform to the design principles, especially when multiple layers are stacked, to ensure the ratio of transmitted light to total reflected light in each layer, the surface smoothness of the structure of the light splitting layer and the light expansion layer must be as high as possible, and the line roughness must be as low as possible to reduce abnormal deflection of light.

[0145] The best method for preparing the structure of the light splitting layer is to use the embossing molding of a precision engraved mold. Other methods such as laser and photolithography cannot guarantee a high-precision surface. The structure design of the light splitting layer adopts the principle of long rib superposition, such as Figure 6 、 Figure 7 、 Figure 8 As shown, the long ribs can also be understood as the grooves left by the diamond carving knife. The shape of the long ribs can be different (such as Figure 9 a), its cross section can be as follows Figure 9 b. Figure 9 c. Figure 9 Three types of triangles shown in d.

[0146] The performance of the light-homogenizing film provided by the present invention was evaluated in the following manner.

[0147] (A) Illumination distribution and relative standard deviation

[0148] like Figure 2As shown, the light-homogenizing component 2 is placed above the LED light board and LED 0, and below the projection screen, or absorption screen 3. The LED light board has a reflective function and integrates a reflective sheet or reflective coating. The light-emitting area of ​​a single LED, S1, is 60 × 60 μm. The absorption screen is infinitely large, and the vertical distance Z between the absorption screen and the LED is 500 μm. Using optical simulation methods such as Light Tools, the illumination distribution within the observation area, S2, of 1200 μm × 1200 μm, on the absorption screen is analyzed and the relative standard deviation (RSD) is calculated.

[0149] Note 1: This setting is scaled down to about 1 / 5 of the actual situation and does not affect the equivalent evaluation;

[0150] Note 2: Since the addition of uniform light components will change the luminous flux and the total amount of radiation received within the inspection range, the degree of change varies with different optical components. Therefore, using relative standard deviation instead of direct standard deviation to evaluate can eliminate the impact of base number changes. (Relative standard deviation = standard deviation / mean)

[0151] Note 3: The light source is set as a cosine illuminator with a beam angle of 30 degrees.

[0152] (B) Light uniformity performance

[0153] Obviously, the lower the RSD, the smaller the difference between the illumination value at each location and the average value, and the more uniform the illumination distribution. Taking RSD0 without the light-diffusing component as the baseline value (100%) and RSD1 after adding the light-diffusing component as the measured value, the improvement in uniformity (U) = (RSD0 / RSD1-1) × 100%. U can be used as an evaluation indicator of the light-diffusing component's light-diffusing performance.

[0154] Note: In the standard architecture described in (A), RSD0 = 5.47

[0155] (C) Beam shape

[0156] like Figure 3a The figure shows a typical spherical coordinate system, with the center of the sphere as the origin of the light source and the Z axis as the emission direction. This spherical coordinate system can be used to describe the initial light source or the beam shape after passing through the uniform light component. Figure 3b It is the beam shape of the Lambertian point light source (original LED light). Figure 3c It is the beam shape after passing through the planar homogenizing film.

[0157] Note 3: Since more than one uniform light-dispersing film is used and there are other films in the backlight structure (such as quantum dot film / fluorescent film, ordinary diffusion film, brightness enhancement film or composite film), the beam shape is only used as a qualitative consideration of the light-splitting effect of a single uniform light-dispersing film. The final beam shape of the backlight source depends on the complete optical film stack. When designing a uniform light-dispersing film, there is no need to worry about large-angle light not being corrected to the normal direction.

[0158] like Figure 4 As shown in FIG. 1 , the present invention provides a light-homogenizing film, which includes a base layer 20 and a light-splitting layer 21 . The light-splitting layer is located on the lower surface of the base layer 20 .

[0159] like Figure 4 As shown in FIG. 2 b , the present invention provides a light-homogenizing film, which includes a base layer 20 , a light-splitting layer 21 and a light-expanding layer 22 . The light-splitting layer is located on the lower surface of the base layer 20 , and the light-expanding layer is located on the upper surface of the base layer 20 .

[0160] Example 1

[0161] The present invention provides a light-homogenizing film, comprising a base layer 20 and a light-splitting layer 21, and a light-expanding layer 22 does not exist. Figure 10 As shown, the light-homogenizing film is a planar light-homogenizing film. The thickness M of the base layer 20 is 75 μm, and the material of the base layer is selected from PET. The light-splitting layer is composed of a transparent polymer resin, and the material is a light-cured acrylic resin (AR), and the refractive index n1 is 1.5. The light-splitting layer is a uniaxial standard surface design: it is composed of long ribs in N directions, and the long ribs are flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is 1, that is, uniaxial light splitting (such as Figure 6 The spectroscopic layer is selected from the standard surface spectroscopic layer, and the corresponding long rib cross section is an isosceles triangle with the left and right waists being the straight lines intercepted by the two ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o The uniformity performance of the uniformity film is good, and the uniformity improvement is U=46%.

[0162] Example 2-36

[0163] For the planar light-homogenizing film provided in Example 1, the other parameters are listed in Table 1.

[0164] Table 1 Design parameters and light-homogenizing properties of the planar light-homogenizing films provided in Examples 1 to 36

[0165] As shown in Table 1, by comparing Examples 1 to 12, it can be seen that the thickness and material of the base layer have little effect on the light-homogenizing performance U of the light-homogenizing film, but the material or refractive index of the light-splitting layer has an impact on U. For the uniaxial light-splitting layer, the higher the refractive index, the more obvious the light splitting, the better the light-homogenizing performance, and the larger U. By comparing Examples 13 to 22, it can be seen that the larger the vertex angle θ of the cross-sectional triangle, the closer the structure is to a plane, the less obvious the light splitting, the worse the light-homogenizing performance, and the smaller U, and vice versa. By comparing Examples 1, 8, 9 and 31 to 36, it can be seen that for the biaxial and triaxial light-splitting layer designs, as with the uniaxial, the higher the refractive index, the more obvious the light splitting, the better the light-homogenizing performance, and the larger U. At the same refractive index, triaxial is better than biaxial and better than uniaxial. By comparing Examples 23 to 30, it can be seen that when the waist of the cross-sectional triangle is bent with different degrees of curvature, it still plays a light-splitting role, and the larger α (the greater the bending), the light-homogenizing performance U is further improved. Note: In Examples 23 to 30, in order to compare with Example 1, the average inclination angle δ of the side edges is set to 45 degrees (consistent with Example 1). If the cross section of Example 23 is a convex arc-edge triangle, then δ = (0.5θ + (0.5θ - α)) / 2 = (θ - α) / 2 = (120 - 30) / 2 = 45 degrees. If the cross section of Example 24 is a concave arc-edge triangle, then δ = (0.5θ + (0.5θ + α)) / 2 = (θ + α) / 2 = (60 + 30) / 2 = 45 degrees. From this result, it can be seen that the arc-edge design has a certain improvement in the uniform light performance compared to the straight-edge design.

[0166] Example 37

[0167] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 11 As shown, the light-homogenizing film is a prism light-homogenizing film. The thickness M of the base layer 20 is 75 μm, the material of the base layer is selected from PET, the light-splitting layer is composed of a transparent polymer resin, the material is a light-cured acrylic resin (AR), and the refractive index n1 is 1.5, and the light-expanding layer is composed of a transparent polymer resin, the material is a light-cured acrylic resin (AR), and the refractive index n2 is 1.5. The light-splitting layer is a biaxial standard surface design: it is composed of long ribs in N directions superimposed, the long ribs are flat on the lower surface of the base layer, the long ribs extend infinitely towards both ends, the long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, that is, biaxial light splitting (such as Figure 7 The spectroscopic layer is selected from the standard surface spectroscopic layer, and the corresponding long rib cross section is an isosceles triangle with the left and right waists being the straight lines intercepted by the two ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o The light expansion layer is a prism layer 221, which is made of triangular prism ribs. The cross section of the triangular prism rib is an isosceles triangle with a base V of 50 μm and a vertex angle β of 90. o The uniformity performance of the uniformity film is good, and the uniformity improvement range is U=91%.

[0168] Examples 38-48

[0169] For the prismatic light-homogenizing film provided in Example 37, the other parameters are listed in Table 2.

[0170] Table 2 Design parameters and light uniformity performance of the prism light uniformity films provided in Examples 37 to 48

[0171] Note: The materials of the light splitting layer and the light expansion layer of Examples 37 to 48 are all AR

[0172] As shown in Table 2, a comparison of Examples 37 to 42 shows that the thickness and material of the base layer, as well as the size of the prisms in the light-expanding layer (i.e., the width V of the base edge), have little effect on the uniformity performance U of the uniformity film. A comparison of Examples 37 and 43 to 45 shows that the vertex angle β of the prism structure does affect U. When the vertex angle is smaller or larger than 90 degrees, the light expansion effect is better, the uniformity performance of the uniformity film is better, and U is larger. A comparison of Examples 46 to 48 shows that the refractive index n2 of the prism structure also affects the uniformity performance.

[0173] Example 49

[0174] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 12 As shown, the light-homogenizing film is a cylindrical light-homogenizing film. The thickness M of the base layer 20 is 75 μm, and the material of the base layer is selected from PET. The light-splitting layer is composed of a transparent polymer resin, and the material is a photocurable acrylic resin (AR), and the refractive index n1 is 1.5. The light-expanding layer is composed of a transparent polymer resin, and the material is a photocurable acrylic resin (AR), and the refractive index n2 is 1.5. The light-splitting layer is a biaxial standard surface design: it is composed of long ribs in N directions superimposed, and the long ribs are flat on the lower surface of the base layer, and the long ribs extend infinitely toward both ends. The long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, that is, biaxial light splitting; the light-splitting layer is selected from the standard surface light-splitting layer, and the corresponding long rib cross-section is an isosceles triangle, and the left and right legs are respectively finitely intercepted straight lines at both ends, that is, the cross-section of the long rib is a right-sided triangle, and the vertex angle θ is 90 o The light diffusion layer is a cylindrical lens layer 222, which is made up of cylindrical lens ribs laid flat. The cross-section of the cylindrical lens is a circular arc with a width (chord length) F of 50μm and a height K of 50μm. The aspect ratio K / F is 0.5. The uniformity performance of this uniformity film is good, with a uniformity improvement of U = 115%.

[0175] Examples 50-60

[0176] For the cylindrical light-homogenizing film provided in Example 49, the other parameters are listed in Table 3.

[0177] Table 3 Design parameters and light uniformity performance of the cylindrical light uniformity films provided in Examples 49 to 60

[0178]

[0179] Note: The materials of the light splitting layer and the light expansion layer in Examples 49 to 60 are all AR

[0180] As shown in Table 3, by comparing Examples 49 to 55, it can be seen that the thickness and material of the base layer, as well as the size of the cylindrical lenses in the light expansion layer (i.e., arc width F), have little effect on the uniform light performance U of the uniform light film. By comparing Examples 49, 56 to 58, it can be seen that the aspect ratio K / F of the cylindrical lens structure has a slight effect on U. When the K / F is larger, the cylindrical lens shape is more convex, the light expansion effect is better, the uniform light performance of the uniform light film is better, and U is larger. By comparing Examples 49, 59, and 60, it can be seen that the refractive index n2 of the cylindrical lens structure also affects the uniform light performance. The higher the refractive index, the larger U.

[0181] Example 61

[0182] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 13 As shown, the light-homogenizing film is a pyramidal light-homogenizing film. The thickness M of the base layer 20 is 75 μm, and the material of the base layer is selected from PET. The light-splitting layer is composed of a transparent polymer resin, and the material is a light-cured acrylic resin (AR), and the refractive index n1 is 1.5. The light-expanding layer is composed of a transparent polymer resin, and the material is a light-cured acrylic resin (AR), and the refractive index n2 is 1.5. The light-splitting layer is a biaxial standard surface design: it is composed of long ribs in N directions superimposed, and the long ribs are flat on the lower surface of the base layer, and the long ribs extend infinitely toward both ends. The long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, that is, biaxial light splitting; the light-splitting layer is selected from the standard surface light-splitting layer, and the corresponding long rib cross-section is an isosceles triangle, and the left and right legs are respectively finitely intercepted straight lines at both ends, that is, the cross-section of the long rib is a right-sided triangle, and the vertex angle θ is 90 o The light diffusion layer is a tetrahedral pyramid layer 224, which is formed by tiling tetrahedral pyramids. The vertices of the tetrahedral pyramids are arranged in a square. The height T of the pyramid is 30 μm, and the angle γ between the side and the height is 45. o The uniformity performance of the uniformity film is good, and the uniformity improvement is U=41%.

[0183] Examples 62-70

[0184] For the pyramidal light-homogenizing film provided in Example 61, the other parameters are listed in Table 4.

[0185] Table 4 Design parameters and light-homogenizing properties of pyramid-shaped light-homogenizing films provided in Examples 61 to 70

[0186]

[0187] Note: The materials of the light splitting layer and the light expansion layer in Examples 61 to 70 are all AR

[0188] As shown in Table 4, a comparison of Examples 61 to 66 shows that the thickness and material of the base layer, as well as the size of the pyramid in the light-expanding layer (i.e., the pyramid height T), have little effect on the uniform light performance U of the uniform light film. A comparison of Examples 61, 67, and 68 shows that the angle γ between the side and the height has a significant impact on U. A smaller γ results in a more convex pyramid shape, better light expansion, and better uniform light performance of the uniform light film, resulting in a larger U. A comparison of Examples 61, 69, and 70 shows that the refractive index n2 of the pyramid structure also affects the uniform light performance; higher refractive index increases U.

[0189] Example 71

[0190] The present invention provides a light-homogenizing film, comprising a base layer 20, a light-splitting layer 21 and a light-expanding layer 22. Figure 14 As shown, the light-homogenizing film is a microlens light-homogenizing film. The thickness M of the base layer 20 is 75 μm, and the material of the base layer is selected from PET. The light-splitting layer is composed of a transparent polymer resin, and the material is a photocurable acrylic resin (AR), and the refractive index n1 is 1.5. The light-expanding layer is composed of a transparent polymer resin, and the material is a photocurable acrylic resin (AR), and the refractive index n2 is 1.5. The light-splitting layer is a biaxial standard surface design: it is composed of long ribs in N directions superimposed, and the long ribs are flat on the lower surface of the base layer, and the long ribs extend infinitely toward both ends. The long ribs in the same direction are closely arranged, and the topological coefficient N is selected from 2, that is, biaxial light splitting; the light-splitting layer is selected from the standard surface light-splitting layer, and the corresponding long rib cross-section is an isosceles triangle, and the left and right waists are respectively finite straight lines intercepted at both ends, that is, the cross-section of the long rib is a right-sided triangle, and the vertex angle θ is 90 o The light diffusion layer is a microlens layer 225. The coordinates of the principal optical axes of three adjacent microlenses are connected to form an equilateral triangle array. The microlenses in the microlens array are closely arranged. The width G of the microlenses is 50μm, the height of the microlenses is H, and the aspect ratio H / G is 0.5. The spacing D and G between the principal optical axes of adjacent microlenses are equal. This light-homogenizing film has good light-homogenizing performance, with a uniformity improvement of U = 103%.

[0191] For the microlens light-homogenizing film provided in Example 71, the other parameters are listed in Table 5.

[0192] Table 5 Design parameters and light uniformity performance of the microlens light uniformity films provided in Examples 71 to 80

[0193]

[0194] Note: The materials of the light splitting layer and the light expansion layer in Examples 71 to 80 are all AR

[0195] As shown in Table 5, a comparison of Examples 71 to 75 shows that the thickness and material of the base layer, as well as the size of the microlenses in the light-expanding layer (i.e., the pyramid width G), have little effect on the uniform light performance U of the uniform light film. A comparison of Examples 71, 76 to 78 shows that the aspect ratio H / G has a certain influence on U. When the aspect ratio is 0.1, the light expansion effect is slightly better, the uniform light performance of the uniform light film is slightly better, and U is slightly larger. A comparison of Examples 71, 79, and 80 shows that the refractive index n2 of the microlens structure also affects the uniform light performance; the higher the refractive index, the larger U.

[0196] Example 81

[0197] The present invention provides a composite light-homogenizing film, comprising a base layer 20, a light-splitting layer 21, a composite adhesive layer 24 and a filter base layer 23. Figure 18 As shown, the base layer 20 and the light-splitting layer 21 form a planar light-homogenizing film. This composite light-splitting film can also be understood as consisting of a planar light-homogenizing film, a composite adhesive layer, and a filter base layer. The base layer 20 has a thickness M of 75 μm and is made of PET. The light-splitting layer is made of a transparent polymer resin, such as a photocurable acrylic resin (AR), with a refractive index n1 of 1.5. The composite adhesive layer is made of a transparent polymer resin, also a photocurable acrylic resin (AR), with a refractive index of 1.5 and a thickness of 1 μm. The filter base layer is a multi-layer co-extruded polymer film. The filter effect is that it reflects blue light at lower incident angles (less than the critical angle), and the reflection ratio decreases at higher incident angles (greater than the critical angle), gradually beginning to transmit blue light. The light splitting layer is designed as a uniaxial standard surface: it is composed of long ribs in N directions, which are laid flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is 1, that is, the uniaxial light splitting (such as Figure 6 The spectroscopic layer is selected from the standard surface spectroscopic layer, and the corresponding long rib cross section is an isosceles triangle with the left and right waists being the straight lines intercepted by the two ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o The uniformity performance of the uniformity film is good, and the uniformity improvement is U=193%.

[0198] Examples 82-120

[0199] For the composite light-homogenizing film provided in Example 81, the other parameters are listed in Table 6.

[0200] Table 6 Design parameters and light-homogenizing properties of the composite light-homogenizing films provided in Examples 81 to 120

[0201]

[0202]

[0203] Note: The composite adhesive layer in Examples 81-120 is made of AR with a refractive index of 1.5. The filter substrate layer is selected from the DC series (e.g., 47QPD5, 49QPD5, 51QPD5, etc.) with a low-angle blue reflection, from the Toray Picasus switchable film product line. As shown in Table 6, a comparison of Examples 1 and 81 shows that the addition of the filter substrate layer significantly improves the uniformity performance (U) of the composite uniformity film compared to the case without the filter substrate layer. A comparison of Examples 81-82 shows that the thickness and material of the substrate layer have little effect on the uniformity performance (U) of the uniformity film, but the material or refractive index of the beam splitter layer does affect U. For a uniaxial beam splitter layer, a higher refractive index results in more pronounced beam splitting, better uniformity performance, and a larger U. A comparison of Examples 93-102 shows that a larger apex angle θ of the cross-sectional triangle and a closer-to-a-plane structure result in less pronounced beam splitting, poorer uniformity performance, and a smaller U, and vice versa. Comparing Examples 81, 88, and 89 with 111-116 shows that for biaxial and triaxial light-splitting layer designs, as with uniaxial, the higher the refractive index, the more pronounced the light splitting, the better the light-homogenizing performance, and the larger U. Furthermore, at the same refractive index, triaxial is superior to biaxial and uniaxial. Comparing Examples 103-110 shows that when the waist of the triangular cross-section is bent at varying degrees of curvature, the light splitting effect is still achieved, and the larger α (greater curvature) further improves the light-homogenizing performance U. Comparing Examples 81 with 117-120 shows that the thickness and refractive index of the composite adhesive layer have little effect on light-homogenizing performance.

[0204] Example 121

[0205] The present invention provides a novel composite light-homogenizing film, which comprises a base layer 20, a light-splitting layer 21, a composite adhesive layer 24, a filter base layer 23 and a microlens layer 27 in order from top to bottom. Figure 20As shown, the base layer 20 and the light-splitting layer 21 form a planar light-homogenizing film. This means that the novel composite light-homogenizing film can also be understood to be composed of a planar light-homogenizing film, a composite adhesive layer, a filter base layer, and a microlens layer. The base layer 20 has a thickness M of 75 μm and is made of PET. The light-splitting layer is made of a transparent polymer resin, such as a light-cured acrylic resin (AR), with a refractive index n1 of 1.5. The composite adhesive layer is made of a transparent polymer resin, also a light-cured acrylic resin (AR), with a refractive index of 1.5 and a thickness of 1 μm. The filter base layer is a multi-layer co-extruded polymer film. The light-filtering effect is that it reflects blue light at smaller incident angles (less than the critical angle), decreases in reflection ratio at larger incident angles (greater than the critical angle), and gradually begins to transmit blue light. The coordinates of the principal optical axes of three adjacent microlenses in the microlens layer are connected to form an equilateral triangle array. The microlenses in the microlens array are closely arranged. The width G2 of the microlens is 50 μm, the height of the microlens is H2, the aspect ratio H2 / G2 is 0.5, the distance D2 between the main optical axes of adjacent microlenses is equal to G2, and the material of the microlens layer is light-cured acrylic resin (AR) with a refractive index n3 of 1.5. The spectroscopic layer is designed as a uniaxial standard surface: it is composed of long ribs in N directions, which are laid flat on the lower surface of the base layer. The long ribs extend infinitely towards both ends, and the long ribs in the same direction are closely arranged. The topological coefficient N is 1, that is, uniaxial spectrometry (such as Figure 6 The spectroscopic layer is selected from the standard surface spectroscopic layer, and the corresponding long rib cross section is an isosceles triangle with the left and right waists being the straight lines intercepted by the two ends, that is, the cross section of the long rib is a right-sided triangle with a vertex angle θ of 90 o The uniformity performance of the uniformity film is good, and the uniformity improvement is U=251%.

[0206] Examples 122-168

[0207] For the novel composite light-homogenizing film provided in Example 121, the other parameters are listed in Table 7.

[0208] Table 7 Design parameters and uniform light performance of the thickened composite uniform light films provided in Examples 121 to 168

[0209]

[0210]

[0211] Note: The composite adhesive layers of Examples 121 to 168 are all made of AR, with a thickness of 1 μm and a refractive index of 1.5. The filter substrate layer is selected from the DC series of Toray Picasus dimming films with a small-angle blue reflection (such as 47QPD5, 49QPD5, and 51QPD5). G2 and H2 are the width and height of the microlens, respectively, in μm. n3 is the refractive index of the microlens layer, and the microlens layer is all made of AR.

[0212] As shown in Table 7, a comparison of Examples 81 and 121 shows that the addition of a microlens layer results in more light incident on the filter substrate layer being reflected, significantly improving the light uniformity performance U of the new composite light-uniforming film compared to the absence of a microlens layer. A comparison of Examples 121-132 shows that the thickness and material of the substrate layer have little effect on the light uniformity performance U of the light-uniforming film, but the material or refractive index of the beam splitting layer does affect U. For a uniaxial beam splitting layer, a higher refractive index results in more pronounced light splitting, better light uniformity, and a larger U. A comparison of Examples 133-142 shows that a larger apex angle θ of the cross-sectional triangle and a closer-to-a-plane structure result in less pronounced light splitting, poorer light uniformity, and a smaller U, and vice versa. A comparison of Examples 121, 128, 129, and 151-156 shows that for biaxial and triaxial beam splitting layer designs, as with uniaxial, a higher refractive index results in more pronounced light splitting, better light uniformity, and a larger U. Furthermore, at the same refractive index, triaxial is superior to biaxial and uniaxial. Comparing Examples 143 to 150, it can be seen that when the waist of the cross-sectional triangle is bent at different degrees of curvature, it still plays a role in light splitting, and the larger the α (the greater the curvature), the better the uniform light performance U. Comparing Examples 121 and 161 to 168, it can be seen that the size of the microlens has little effect on the uniform light performance, but the aspect ratio H2 / G2 has a significant impact on the uniform light performance. When H2 / G2 decreases from 0.5 to 0.1, the uniform light performance decreases due to the increase in the microlens layer. In addition, the refractive index of the microlens layer also affects the uniform light performance. A high refractive index significantly deflects light, allowing more light to be reflected at small angles, resulting in better uniform light performance.

[0213] It should be noted that this patent application focuses on the design principles of the composite light-homogenizing film and does not limit the design of the filter substrate layer. The manufacturer and model of the filter substrate layer used do not limit the scope of protection of this invention. All equivalent variations and modifications of the composite light-homogenizing film according to this invention are covered by the patent scope of this invention.

[0214] It should be noted that the above descriptions are only some typical embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent changes and modifications made based on the content of the present invention are included in the patent scope of the present invention.

Claims

1. A new type of composite light-homogenizing film, characterized in that: The novel composite light-homogenizing film is composed of a microlens layer, a filter base layer, a composite adhesive layer, a light-splitting layer, and a base layer from bottom to top; The material of the base layer is PET; the spectroscopic layer is composed of a transparent polymer resin, which is a light-cured acrylic resin with a refractive index n1 of 1.65; the composite adhesive layer is composed of a transparent polymer resin, which is a light-cured acrylic resin with a refractive index of 1.5 and a thickness of 1 μm; the filter base layer is a multi-layer co-extruded polymer film, and the filtering effect is that it reflects blue light when the angle is less than the critical angle, and the reflection ratio decreases when the angle is greater than the critical angle, and gradually begins to transmit blue light; the coordinates of the main optical axes of three adjacent microlenses in the microlens layer are connected to form an equilateral triangle array, and the microlenses in the microlens array are closely arranged; the width G2 of the microlens is 50 μm, the height of the microlens is H2, the aspect ratio H2 / G2 is 0.5, the spacing D2 between the principal optical axes of adjacent microlenses is equal to G2, the material of the microlens layer is a light-curing acrylic resin, and the refractive index n3 is 1.5; the light-splitting layer is composed of long ribs stacked in N directions, the long ribs are flat on the lower surface of the base layer, the long ribs extend infinitely toward both ends, and the long ribs in the same direction are closely arranged, and the N directions divide the 360-degree azimuth angle into equal parts, where N is 3; the long ribs in the light-splitting layer have the same cross-section, which is an isosceles triangle, with the left waist and the right waist being straight lines finitely intercepted at both ends, and the base being a straight line; the cross-section of the long ribs is a right-sided triangle, and the vertex angle θ is 90°.

2. A method for preparing the novel composite light-homogenizing film according to claim 1, characterized in that: A micro-replication or hot pressing process is used on the back of the base layer to prepare a spectroscopic layer using a transparent polymer resin; a micro-replication process is used on the back of the filter base layer to prepare a microlens layer using a transparent polymer resin; a coating process is used on the front of the filter base layer to prepare a composite adhesive layer using a transparent polymer resin, and the composite layer is combined with the spectroscopic layer; the tip of the spectroscopic layer is embedded in the composite adhesive layer and then UV curing is performed.

Images