CN114114502B

CN114114502B - Polarization-preserving optical film and interference-relieving polarization-preserving composite prism film

Info

Publication number: CN114114502B
Application number: CN202111002629.6A
Authority: CN
Inventors: 夏寅; 冯金刚; 叶群; 高斌基; 于振江; 李刚; 唐海江; 张彦
Original assignee: Ningbo Exciton Technology Co Ltd
Current assignee: Ningbo Exciton Technology Co Ltd
Priority date: 2020-08-31
Filing date: 2021-08-30
Publication date: 2024-09-06
Anticipated expiration: 2041-08-30
Also published as: CN114114502A; CN114114504A; CN114114505A; CN114114503A; CN114114506A; CN114114504B

Abstract

The invention relates to a de-interference polarization-preserving composite prism film, in particular to a polarization-preserving composite prism film applied to an LCD linear polarization backlight source. The invention provides a de-interference polarization-preserving composite film and a preparation method thereof, aiming at solving the problem that an optical film in the traditional backlight can generate depolarization in a polarized light source synergistic scheme. The interference-removing polarization-preserving composite prism film comprises an upper polarization-preserving substrate layer, an upper structure layer, an upper composite layer, a lower polarization-preserving substrate layer, a lower structure layer and a lower back coating. The upper structure layer is positioned on the upper surface of the upper matrix layer, and the upper composite layer is positioned on the lower surface of the upper matrix layer. The lower structure layer is a left-right shaking prism layer and is positioned on the upper surface of the lower polarization-preserving substrate layer, and the lower back coating is positioned on the lower surface of the lower substrate layer. When the linearly polarized light in the LCD backlight passes through the interference-relieving polarization-preserving composite prism film, the polarization-preserving degree of the incident light can be kept higher than or equal to 85 percent, the high transmission of the polarizer under the LCD is ensured, and the utilization rate of the backlight is further improved.

Description

Polarization-preserving optical film and interference-relieving polarization-preserving composite prism film

Technical Field

The invention relates to a polarization-maintaining optical film, in particular to a polarization-maintaining optical film and a polarization-maintaining composite prism film applied to an LCD linear polarization backlight source.

Background

In the traditional liquid crystal display field (LCD), a backlight module is required to provide a light source for the display of a liquid crystal panel, and an LED point light source can be converted into a uniform planar light source through various optical films and light guide plates in the backlight module. However, the light energy of the planar light source is actually very low in utilization ratio for the liquid crystal panel.

One of the reasons is that the transmittance of the lower polarizer (13) of the liquid crystal panel is only 40% (as shown in table 1). Because the conversion efficiency from the point light source to the surface light source varies greatly according to the backlight design (direct type or side-in type), the light energy attenuation process of the conventional liquid crystal display panel to the backlight source is discussed based on the surface light source as 100%. It can be seen that the loss is the most (about 70%) when passing through the filter, because white light is filtered out to generate RGB monochromatic light, and then the loss is more serious (about 60%) when passing through the lower polarizer, because the ordinary light source needs to undergo the dichroic absorption process of the PVA layer to form linear polarized light, only the linear polarized light (22) with the polarization direction parallel to the transmission axis of the polarizer is remained, all the linear polarized light (23) in the vertical direction is absorbed, as shown in fig. 1, the light emitted by the backlight module (14) is a part of polarized light (21), after the part of polarized light (21) passes through the lower polarizer (13), the linear polarized light (22) in the parallel direction is smoothly transmitted, the linear polarized light (23) in the vertical direction is absorbed by the lower polarizer (13), the linear polarized light (23) in the parallel direction is twisted by the liquid crystal when passing through the liquid crystal panel (12) and changed in the polarization direction, the linear polarized light (23) in the vertical direction is converted and smoothly transmitted from the upper polarizer (11), and the emergent light is finally the linear polarized light (23) in the vertical direction.

TABLE 1 light energy attenuation Process for backlight sources of conventional LCD panels

Sequence of investigation	Attenuation position	Attenuation causes	Transmittance of light	Residual light energy
					6	Cover plate	Surface reflection	90％	9.2％
5	Upper polaroid	Surface reflection	90％	10.3％
					4	Optical filter	Wavelength cut-off, absorption	30％	11.4％
3	Liquid crystal layer	Polarized light transmission	95％	38％
					2	Lower polarizer	Surface reflection, polarization	40％	40％
1	Surface light source	Backlight material light distribution conversion	/	100％
					0	Point light source	/	/	/

If the backlight surface light source is polarized before entering the lower polarized light and is converted into linear polarized light parallel to the lower polarized light, the transmittance of the lower polarized light to the backlight surface light source is greatly improved, the utilization rate of the whole liquid crystal panel to the surface light source is greatly improved, the brightness of the display is improved, and the power and energy are saved.

The traditional synergy scheme is to add a Reflective Polarizer (RP) (15) designed by adopting a multi-layer film system on the original backlight structure at the rear end of the polarizer: the reflective polarizer (15) can transmit completely polarized P light and reflect S light; the S light emits depolarized light in the backlight system to reform partial polarized light; the partially polarized light is repeatedly transmitted through the RP to produce more P light; through multiple times of circulation until the energy is exhausted; the final increase in P light can increase the light energy utilization by 20-30% compared with the original structure. As shown in fig. 2, the light emitted by the backlight module (14) is a part of polarized light (21), the part of polarized light (21) enters the reflective polarizer (15), and the reflective polarizer (15) can transmit the linearly polarized light (22) in the parallel direction and reflect the linearly polarized light (23) in the vertical direction; whereas linearly polarized light (23) in the vertical direction is depolarized in the backlight system, and partially polarized light (21) is reformed; after the linearly polarized light (22) in the parallel direction passes through the lower polarizer (13), the linearly polarized light (22) in the parallel direction is smoothly transmitted, no linearly polarized light (23) in the vertical direction is absorbed at the moment, the linearly polarized light in the parallel direction is twisted by liquid crystal and changes the polarization direction when passing through the liquid crystal panel (12), the linearly polarized light is converted into the linearly polarized light (23) in the vertical direction and is smoothly transmitted through the upper polarizer (11), and the emergent light is finally the linearly polarized light (23) in the vertical direction.

However, the reflective polarizer is very expensive due to its complicated equipment and process, and less supply resources. Therefore, a new synergistic scheme is needed.

Another feasible scheme is that the front end is polarized, namely, a linear polarized light source is adopted by the backlight module, linear polarized light is emitted from the beginning, and the direction of the polarized light is kept consistent with the light transmission axis of the lower polarizer (13). As shown in fig. 3, the light emitted by the backlight module (14) is linearly polarized light (22) in a parallel direction, the linearly polarized light (22) in the parallel direction is smoothly transmitted after passing through the lower polarizer (13), the linearly polarized light is twisted by the liquid crystal and changes the polarization direction when passing through the liquid crystal panel (12), the linearly polarized light is converted into linearly polarized light (23) in a vertical direction and is smoothly transmitted from the upper polarizer (11), and the emergent light is finally linearly polarized light (23) in the vertical direction. However, in the process of converting the linear polarization point light source into the surface light source, the traditional optical film has optical anisotropy, polarization retention is very low (complete polarized light is incident, more or less depolarization can occur after passing through the optical film, so that the polarization degree of emergent light is reduced, partial polarized light is generated, the ratio of the polarization degree of emergent light to the polarization degree of incident light, namely, the polarization degree of emergent light can be expressed by the polarization degree of emergent light because the polarization degree of incident light is 1), the polarization degree of the final surface light source is generally between 50 and 70%, the polarization degree of the final surface light source is sharply reduced, a significant depolarization phenomenon is generated, a large part of the partial polarized light can still be filtered by the lower polarizer, the synergy expectation is not reached, as shown in fig. 4, after the linear polarized light (22) in the parallel direction passes through the traditional optical film (3), the emergent light is the partial polarized light (21), the linear polarized light (22) in the parallel direction is smoothly transmitted through the lower polarizer (13), the linear polarized light (23) in the perpendicular direction is also expressed by the polarization degree of the emergent light, when the linear polarized light in the parallel direction passes through the liquid crystal panel (12) is twisted, and the linear polarized light in the perpendicular direction is smoothly transmitted from the liquid crystal panel (23) to the perpendicular polarized light (11).

Disclosure of Invention

The invention provides a polarization-preserving optical film and a preparation method thereof, aiming at solving the problem that the optical film in the traditional backlight can generate serious depolarization phenomenon in a polarized light source synergistic scheme. The polarization-preserving optical film provided by the invention has higher polarization-preserving degree for incident linearly polarized light, and reduces the depolarization phenomenon.

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

the invention provides a polarization maintaining optical film which comprises a polarization maintaining substrate layer, a first structural layer and/or a second structural layer, wherein the first structural layer is positioned on the upper surface of the polarization maintaining substrate layer, and the second structural layer is positioned on the lower surface of the polarization maintaining substrate layer.

When the linearly polarized light passes through the polarization-preserving optical film, the polarization-preserving optical film has a polarization-preserving degree of greater than or equal to 80% for the incident linearly polarized light.

Further, when linearly polarized light in the LCD backlight passes through the polarization maintaining optical film, polarized incident light can maintain a high degree of polarization, and the degree of polarization is greater than or equal to 80%. Thereby ensuring the high transmission of the polarizer under the LCD and greatly improving the utilization rate of the backlight source.

The optical film in the conventional backlight refers to an existing diffusion film, microlens film, prism film, or inverse prism film.

The polarization maintaining optical film is one of a polarization maintaining diffusion film, a polarization maintaining micro lens film, a polarization maintaining prism film and a polarization maintaining inverse prism film.

The polarization-preserving optical film provided by the invention is an improvement on the existing optical film, and the material of a substrate layer (also called a supporting layer) of the existing optical film is changed into a material with high polarization-preserving degree for linearly polarized light.

The polarization-preserving degree of the polarization-preserving substrate layer is more than 99%.

The polarization-preserving substrate layer is made of optically isotropic transparent polymer.

The thickness T of the polarization-maintaining substrate layer is 25-250 mu m.

The material of the polarization-maintaining substrate layer is selected from one or a combination of at least two of polymethyl methacrylate (PMMA), polycarbonate (PC), cellulose Triacetate (TAC) and cycloolefin polymer (COP).

The haze of the polarization-maintaining diffusion film is 60-98%.

The first structural layer of the polarization-maintaining diffusion film is an atomization layer, the second structural layer is not or is the same as the atomization layer, and the atomization layer is selected from a particle-free coating or a particle-containing coating.

The haze of the first atomization layer/the second atomization layer is 5-98%.

The particle-free coating of the polarization-maintaining diffusion film is composed of transparent polymer resin. The particle-coated layer is composed of transparent polymer resin and transparent polymer particles; the particle diameter of the transparent polymer particles is 1-20 mu m.

The haze of the polarization maintaining micro-lens film is 60-98%.

The first structural layer of the polarization-maintaining microlens film is a microlens array layer; in the micro lens array layer, coordinates of main optical axes of adjacent three micro lenses are connected to form a regular triangle, or coordinates of main optical axes of adjacent four micro lenses are connected to form a square; the microlenses in the microlens array are closely arranged.

The haze of the microlens array layer is 60-98%.

In the microlens array layer, the distance D between the main optical axes of adjacent microlenses is 10 to 50 μm, the width of the microlens is W (w=d), the height of the microlens is H, and the aspect ratio H/W is 0.05 to 0.5.

The first structural layer of the polarization-maintaining prism film is a prism layer, and the second structural layer is absent or an atomization layer; the prism layer is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom edges of the triangles are 10-100 mu m, and the vertex angles are 75-105 degrees; the haze of the atomization layer is 0-30%.

The second structural layer of the polarization-maintaining inverse prism film is an inverse prism layer, and the first structural layer is absent or an atomization layer; the inverted prism layer is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle or a common triangle, the width L of the bottom edge of each triangle is 10-100 mu m, the vertex angle theta is 40-80 degrees, preferably 60 degrees, one larger bottom angle alpha is 90-0.5θ+gamma, gamma is 0-10 degrees, the cross section is an isosceles triangle when gamma is 0 degrees, and the cross section is a common triangle when gamma is greater than 0 degrees. The haze of the atomization layer is 0-60%.

The atomization layer is made of one of AR (ACRYLIC RESIN, acrylic resin or modified acrylic resin), PMMA, PC or Polyurethane (PU). AR is preferably a photo-curing process, PMMA and PC are preferably a hot-pressing process, and PU is preferably a hot-curing process.

When the atomized layer is a particle-coated layer, the refractive index na of the transparent polymer resin is selected from 1.4 to 1.65. When the atomized layer is a particle-free coating, the refractive index nb of the transparent polymer resin is selected from 1.4 to 1.65.

The transparent polymer particles are selected from one or a combination of at least two of PMMA, PBMA (polybutylmethacrylate), PS (polystyrene), PU (polyurethane) and organosilicon.

The microlens array layer is formed of a transparent polymer resin, and the transparent polymer resin is made of one selected from AR, PMMA and PC. AR is preferably a photo-curing process, and PMMA and PC are preferably hot-pressing processes. The refractive index nc of the transparent polymer resin of the microlens array layer is selected from 1.4 to 1.65.

The prism layer is composed of transparent polymer resin, and the material of the transparent polymer resin is selected from one of AR, PMMA or PC. AR is preferably a photo-curing process, and PMMA and PC are preferably hot-pressing processes. The refractive index nd of the transparent polymer resin is selected from 1.5 to 1.65.

The inverse prism layer is composed of transparent polymer resin, and the material of the transparent polymer resin is selected from one of AR, PMMA or PC. AR is preferably a photo-curing process, and PMMA and PC are preferably hot-pressing processes. The refractive index ne of the transparent polymer resin of the prism layer is selected from 1.5 to 1.65.

Further, in the polarization-maintaining diffusion film provided by the invention, the first structural layer is an atomization layer DL (Diffusion layer), and the second structural layer is not present. The thickness T of the substrate layer is 50-250 mu m, the material of the polarization-preserving substrate layer is PC, TAC, PMMA or COP, the optical isotropy is achieved, the polarization-preserving degree is more than 99%, and the haze of the polarization-preserving diffusion film is 98%. The haze of the first atomization layer is 98%, the atomization layer is a particle coating, the transparent polymer resin is selected from PU or AR, the transparent polymer particles are PMMA, PS, organic silicon or PU, the particle size d is 5-15 mu m or 8-20 mu m, and the refractive index na of the transparent polymer resin is 1.4, 1.5 or 1.65. The polarization maintaining diffusion film has a polarization maintaining degree of 81-83% (e.g., 81%, 82%, or 83%).

According to the polarization-maintaining diffusion film provided by the invention, the first structural layer is an atomization layer DL (Diffusion layer), and the second structural layer is absent. The thickness T of the substrate layer is 250 mu m, the polarization-preserving substrate layer is made of PC, the optical isotropy is achieved, the polarization-preserving degree is more than 99%, and the haze of the polarization-preserving diffusion film is 98%. The haze of the first atomization layer is 98%, the atomization layer is of a particle-free coating type, the transparent polymer resin is PC, and the refractive index na of the transparent polymer resin is 1.5. The polarization-preserving degree of the polarization-preserving diffusion film is 83%.

According to the polarization-maintaining diffusion film provided by the invention, the first structural layer is an atomization layer, and the second structural layer is an atomization layer. The thickness T of the substrate layer is 50-250 μm (for example, 25 μm,50 μm,100 μm,125 μm,250 μm), the material of the polarization-preserving substrate layer is selected from PC or PMMA, the optical isotropy is that the polarization-preserving degree is >99%, and the haze of the polarization-preserving diffusion film is 60-98% (for example, 60%, 80%, 90%, 95% or 98%). The haze of the first atomization layer is 98%, the type of the atomization layer is particle coating, the transparent polymer resin is PU or AR, the transparent polymer particles are PMMA, the particle size d is 5-15 mu m, and the refractive index na of the transparent polymer resin is 1.5 or 1.65. The haze of the second atomization layer is 5%, the second atomization layer is a particle coating, the transparent polymer resin is AR, the transparent polymer particles are PMMA, the particle size d is 1-3 mu m, or 5-15 mu m, and the refractive index na of the transparent polymer resin is 1.5.

According to the polarization-maintaining diffusion film provided by the invention, the first structural layer is an atomization layer, and the second structural layer is an atomization layer. The thickness T of the substrate layer is 250 mu m, the polarization-preserving substrate layer is made of PC, the optical isotropy is achieved, the polarization-preserving degree is more than 99%, and the haze of the polarization-preserving diffusion film is 98%. The haze of the first atomization layer is 98%, the type of the atomization layer is particle coating, the transparent polymer resin is PU or AR, the transparent polymer particles are PMMA, the particle size d is 5-15 mu m, and the refractive index na of the transparent polymer resin is 1.5 or 1.65. The haze of the second atomization layer is 5%, the atomization layer is a particle-free coating and is composed of transparent polymer resin AR, and the refractive index nb of the transparent polymer resin is 1.5 or 1.6. The polarization-preserving degree of the polarization-preserving diffusion film is 80%.

Further, the present invention provides a polarization-preserving microlens film, wherein the first structural layer is a microlens array layer ML (Microlens layer), and the second structural layer is not present. The thickness T of the substrate layer is 25-250 μm (for example, 25-250 μm,50 μm,100 μm,125 μm,250 μm), the material of the polarization-preserving substrate layer is selected from PC or PMMA, the optical isotropy is realized, the polarization-preserving degree is >99%, and the haze of the polarization-preserving microlens film is 60% -98% (for example, 60%, 70%, 85%, 92%, 96%, 98%). The haze of the microlens array layer is 98%, and the microlens array layer is formed of a transparent polymer resin AR or PC having a refractive index nc of 1.4 to 1.65 (e.g., 1.4, 1.5, 1.65). In the microlens array layer, the distance D between the main optical axes of adjacent microlenses is 10 μm-50 μm (e.g., 10 μm, 20 μm, 35 μm,50 μm), the width of the microlens is W (W=D), the height of the microlens is H, and the aspect ratio H/W is 0.05-0.5 (e.g., 0.05, 0.1, 0.2, 0.5); the polarization maintaining microlens has a polarization maintaining degree of 80% -97% (e.g., 80%, 85%, 88%, 90%, 95%, 97%).

The invention provides a polarization-maintaining microlens film, wherein a first structural layer is a microlens array layer, and a second structural layer is an atomization layer. The thickness T of the substrate layer is 250 mu m, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy, the polarization-preserving degree is more than 99%, and the haze of the polarization-preserving micro lens film is 96%. The haze of the microlens array layer was 98%, and the microlens array layer was composed of a transparent polymer resin AR having a refractive index nc of 1.5. In the microlens array layer, the distance D between the main optical axes of adjacent microlenses is 50 μm, the width of the microlens is W (w=d), the height of the microlens is H, and the aspect ratio H/W is 0.5. The haze of the atomization layer is 5%, the atomization layer is a particle-free coating and consists of a transparent polymer AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization-preserving degree of the polarization-preserving micro-lens film is 85%.

The invention provides a polarization-maintaining microlens film, wherein a first structural layer is a microlens array layer, and a second structural layer is an atomization layer. The thickness T of the substrate layer is 100 mu m, the material of the polarization-preserving substrate layer is selected from TAC, PMMA or COP, the optical isotropy is realized, the polarization-preserving degree is more than 99%, and the haze of the polarization-preserving micro lens film is 96%. The haze of the microlens array layer was 98%, and the microlens array layer was formed of a transparent polymer resin AR or PMMA, the refractive index nc of which was 1.5. In the microlens array layer, the distance D between the main optical axes of adjacent microlenses is 50 μm, the width of the microlens is W (w=d), the height of the microlens is H, and the aspect ratio H/W is 0.5. The haze of the atomization layer is 5%, the atomization layer is a particle coating and consists of transparent polymer resin AR and transparent polymer resin particles PMMA, the refractive index nb of the transparent polymer resin is 1.5, and the particle size of the polymer resin particles PMMA is 3-5 mu m. The polarization-preserving degree of the polarization-preserving micro-lens film is 85%.

Further, the present invention provides a polarization-preserving prism film, wherein the first structural layer is a prism layer PL (Prism layer), and the second structural layer is absent. The thickness T of the substrate layer is 25 μm-250 μm (for example, 25 μm,50 μm,100 μm,125 μm,250 μm), the material of the polarization-preserving substrate layer is PC, TAC, PMMA, or COP, optical isotropy, polarization-preserving degree >99%, the prism layer is formed of transparent polymer resin AR, PMMA or PC, and the refractive index nd of the transparent polymer resin is 1.5-1.65 (for example, 1.5, 1.55 or 1.65). The prism layer is formed by tiling triangular prism ribs, the cross section of the triangular prism ribs is isosceles triangle, the base of the triangle is 10-100 μm (e.g. 10 μm, 20 μm,50 μm,100 μm), and the vertex angle is 75-105 ° (e.g. 75 °, 90 °, 105 °). The polarization maintaining degree of the polarization maintaining prism film is 98%.

The invention provides a polarization-maintaining prism film, wherein the first structural layer is a prism layer PL (Prism layer), and the second structural layer is an atomization layer. The thickness T of the substrate layer is 250 mu m, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy and polarization-preserving degree is more than 99%, the prism layer is composed of transparent polymer resin AR, and the refractive index nd of the transparent polymer resin is 1.55. The prism layer is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom edges of the triangles are 50 mu m, and the vertex angles are 90 degrees. The haze of the atomization layer is 5% -30%, the atomization layer is a particle-free coating and is composed of a transparent polymer AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization maintaining degree of the polarization maintaining prism film is 95% -97%.

Further, the invention provides a polarization-maintaining inverse prism film, wherein the first structural layer is not present, and the second structural layer is an inverse prism layer RL (Rverse-PRISM LAYER). The thickness T of the substrate layer is 25-250 mu m, the material of the polarization-preserving substrate layer is PC, TAC, PMMA or COP, the optical isotropy is realized, the polarization-preserving degree is more than 99%, the inverse prism layer is formed by transparent polymer resin AR, PC or PMMA, and the refractive index nd of the transparent polymer resin is 1.5-1.65 (for example, 1.5, 1.55 or 1.65). The inverted prism layer is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle or a common triangle, the width L of the base of the triangle is 10-100 μm (such as 10 μm, 20 μm, 50 μm and 100 μm), the vertex angle theta is selected from 40-90 degrees (such as 40 degrees, 60 degrees, 80 degrees or 90 degrees), one larger base angle alpha is 90-0.5θ+gamma, and the deflection angle gamma is 0-10 degrees. The polarization maintaining degree of the polarization maintaining inverse prism film is 98%.

The invention provides a polarization-maintaining inverse prism film, wherein a first structural layer is an atomization layer, and a second structural layer is an inverse prism layer RL (Rverse-PRISM LAYER). The thickness T of the substrate layer is 250 mu m, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy and polarization-preserving degree is more than 99%, the inverse prism layer is composed of transparent polymer resin AR, and the refractive index nd of the transparent polymer resin is 1.55. The inverted prism layer is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle, the width L of the bottom edge of the triangle is 50 mu m, the vertex angle theta is selected from 60 degrees, one larger bottom angle alpha is 90 degrees to 0.5θ+gamma, and the deflection angle gamma is 0 degrees. The haze of the atomization layer is 30% -60%, the atomization layer is a particle-free coating and is composed of a transparent polymer AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization maintaining degree of the polarization maintaining prism film is 90% -95%.

The invention also provides a preparation method of the polarization-preserving optical film, wherein the front/back of the polarization-preserving substrate layer is sequentially coated, micro-replicated or hot-pressed to form a first structural layer or a second structural layer by using a resin or a resin formula containing particles; the method is characterized in that the method is suitable for preparing an atomization layer of a polarization-maintaining diffusion film, and is suitable for preparing the atomization layer, the micro-lens layer and the prism layer of the polarization-maintaining diffusion film, the polarization-maintaining micro-lens film, the polarization-maintaining prism film and the polarization-maintaining inverse prism film by micro-replication and hot press molding.

Further, the preparation method of the polarization-preserving optical film comprises the following steps:

(1) Coating a first structural layer on the front surface of the polarization-maintaining substrate layer serving as a supporting layer to obtain a polarization-maintaining optical film containing the first structural layer;

(1) A mould roller (roller 1) for preparing the first structural layer;

(2) Using the polarization-preserving substrate layer as a supporting layer, and micro-copying or hot-pressing the first structural layer (convex) on the front surface by using a roller 1 to obtain a polarization-preserving optical film containing the first structural layer;

(1) Coating a second structural layer on the back surface of the polarization-maintaining substrate layer serving as a supporting layer to obtain a polarization-maintaining optical film containing the second structural layer;

(1) Preparing a mold roll (roll 2) of the second structural layer;

(2) Using the polarization-maintaining substrate layer as a supporting layer, and micro-copying or hot-pressing the back of the polarization-maintaining substrate layer by using a roller 2 to form a second structural layer, thereby obtaining a polarization-maintaining optical film containing the second structural layer; ;

(1) Coating a first structural layer on the front surface by taking the polarization-maintaining substrate layer as a supporting layer to obtain a semi-finished product containing the first structural layer;

(2) Coating a second structural layer on the back of the semi-finished product prepared in the step (1) to obtain a polarization maintaining optical film containing the first structural layer and the second structural layer;

(1) A mould roller (roller 1) for preparing the first structural layer;

(2) Microreplicating or hot-pressing the front surface of the polarization-maintaining substrate layer by using a mold roller to form a first structural layer, so as to obtain a semi-finished product containing the first structural layer;

(3) Preparing a mold roll (roll 2) of the second structural layer;

(4) Microreplicating or hot-pressing the back surface of the polarization-maintaining substrate layer by using a roller 2 to form a second structural layer, thereby obtaining a polarization-maintaining optical film simultaneously containing the first structural layer and the second structural layer;

It should be noted that the processing manner of the first structural layer and the second structural layer should be selected according to the type of the structural layer and the type of the material, which is not preferred in the present invention;

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

The polarization maintaining optical film can be used as an optical functional material for an optical system needing polarization maintaining. The linear polarization film is particularly suitable for an LCD linear polarization backlight source, and can keep higher polarization degree when linear polarized light in the backlight passes through the polarization-maintaining optical film, ensure the final high transmission of a polarizer under the LCD, and greatly improve the utilization rate of the backlight source.

Compared with the prior art, the polarization maintaining optical film provided by the invention can be matched with a linear polarized light source for design, so that the linear polarized light source is conveniently generated, a reflective polarizer with complex process and high price is not needed, the high transmission of the polarizer under the LCD can be ensured, the utilization rate of the backlight source is improved, the cost performance of a synergistic scheme is higher, and the advantage is obvious.

Firstly, the traditional composite film prism film has low interference rejection capability requirement on the lower prism film because the upper optical film adopts an atomization layer with higher haze, but the design is not suitable for the polarization maintaining composite prism film, and the main reason is that the high haze can bring higher polarization maintaining loss. Therefore, if the design of the underlying prism itself has better interference rejection capability, the high haze of the atomized layer can be independent, thereby achieving higher polarization-preserving degree.

Secondly, the research finds that the rotation angle of the prism layer structure in the backlight has a certain influence on the polarization-preserving degree: 1. the polarization-preserving degree is highest when the included angle between the prism rib and the polarizer transmission axis is 0 degree; 2. as the angle increases, the polarization maintaining degree is continuously reduced, and the minimum value is reached at 45 degrees; 3. and then continuously rises again, and the polarization maintaining degree approaches to 0 degree at 90 degrees. Therefore, it is also necessary to avoid that the prism ribs of the underlying prism layer in the polarization maintaining composite prism film are cut by the forced corner due to interference elimination. Therefore, the development of a polarization-preserving composite prism film which can be used for interference elimination without turning angles or with extremely small turning angles is considered.

Considering the bonding performance of the upper bonding layer and the lower prism of the composite film, the prism structure of the lower prism layer needs to have a certain number of contour structural designs.

In order to further improve the adaptability of the panels with different resolutions, the prism layer is required to enhance the interference elimination performance by adopting a dithering structure, and researches show that the left-right dithering is more suitable for the composite prism film than the up-down dithering, the up-down dithering can reduce the stability of the binding force between two sheets (the contact area is large and small along with the fluctuation), and the left-right dithering can reversely increase the binding force (when the depth distance is fixed, the curve length is longer than that of a straight line, so that the contact area is increased by the left-right dithering).

The invention provides an interference-removing polarization-preserving composite prism film which comprises an upper polarization-preserving substrate layer, an upper structure layer, an upper composite layer, a lower polarization-preserving substrate layer, a lower structure layer and a lower back coating. The upper structure layer is positioned on the upper surface of the upper polarization-preserving substrate layer, and the upper composite layer is positioned on the lower surface of the upper substrate layer. The lower structure layer is a left-right shaking prism layer and is positioned on the upper surface of the lower polarization-preserving substrate layer, and the lower back coating is positioned on the lower surface of the lower substrate layer.

The left and right shaking prism layers are formed by tiling a plurality of identical or different triangular prism ribs. The triangular prism ribs shake left and right in the longitudinal direction. The underlying structural layer is also referred to as an underlying prismatic layer, simply a prismatic layer.

The resin of the upper composite layer is combined with the peak tip of the lower prism layer after curing.

The cross section of the triangular prism rib is isosceles triangle.

The ridge line of the triangular prism rib shakes left and right. The right and left dithered triangular prism ribs are also referred to as right and left dithered structures.

The ridge line (the trace line of the peak tip along the longitudinal direction) of the triangular prism rib is a free curve of left-right jitter variation, and the jitter amplitude V (the horizontal distance between the leftmost side and the rightmost side) is 1 to 10 μm, preferably 2 to 4 μm.

The jitter amplitude is less than the bottom width W _min of the narrowest triangular prism rib in the transverse period.

The length of the base of the triangle is any t of 30-80 mu m, and t is selected from any integer between 1-7, preferably 2 or 3;

The vertex angle of the triangle is any k types of 75-105 degrees, k is any integer between 1 and 7, and is preferably 2 or 3;

The cross section of the prism layer is any combination of different triangles.

The prism layer has a lateral period (cross-sectional repeat unit width) of 80 to 600 μm. In the same period, the number of the base line types t and the number of the top angles k are respectively 1 to 7, and are respectively preferably 2 to 3.

And in the transverse period of the prism layer, the highest prism structure is defined as a main peak prism, and other prisms are secondary peak prisms. The ratio of the main peak prism to the secondary peak prism is 1: s, s (abbreviated as primary-secondary ratio s) is selected from 1 to 3, preferably 2. When s is 1, the prism structure 1 is high and low in collocation, the chaotic degree (interference removing capability) is weak, when s is 3, the prism structure 1 is high and low in collocation, the bonding strength is weak, and when s is 2, the prism structure 1 is high and low in collocation, and the comprehensive performance is good.

The upper structure layer is an atomization layer, and the haze is 60-95%.

The lower back coating is an atomization layer, and the haze is 5-30%.

The atomization layers are particle-free coatings and are composed of transparent polymer resin AR, and the refractive index nb of the transparent polymer resin is 1.5.

The prism layer is composed of a transparent polymer resin AR having a refractive index nd of 1.55. The upper composite layer is composed of a transparent polymer resin AR having a refractive index nf of 1.47. The resin of the upper composite layer is combined with the peak tip of the lower prism layer after curing.

Further, the length of the base of the triangle of the cross section of the triangular prism rib is at least 2, and further, the angle of the apex angle of the triangle of the cross section of the triangular prism rib is at least 2.

The triangular prism ribs include triangular prism ribs having different structures.

The triangular prism rib has 2-7 structures.

Further, the prism layer is formed by tiling triangular prism ribs, and the triangular prism ribs are provided with a first structure and a second structure. The first structure and the second structure form a cycle. The prismatic layer includes a number of periods. The ridge line (the trace line of the peak tip along the longitudinal direction) of the triangular prism rib is a free curve of left-right jitter variation, and the jitter amplitude V (the horizontal distance between the leftmost side and the rightmost side) is 6 to 10 μm.

Further, one cycle includes 1 first structure and 1 second structure. The jitter amplitude V of the right-left jitter of the triangular prism rib is 10 μm.

Further, one cycle includes 1,2, or 3 first structures, and 1,2, 3,4, or 6 second structures. The jitter amplitude V of the left and right jitter of the triangular prism rib is 6-8 mu m.

Further, the prism layer is formed by tiling triangular prism ribs, and the triangular prism ribs are provided with a first structure and a second structure. The first structure and the second structure form a cycle. The prismatic layer includes a number of periods. The length of the base of the triangle of the cross section of the first structural triangular prism rib is 50 mu m, the angle of the vertex angle is 90 DEG, and the number in one period is 1; the length of the base of the triangle of the cross section of the second triangular prism rib is 30 μm, the angle of the apex angle is 75 °, and the number in one period is 1. That is, one period includes 1 first structure and 1 second structure, and the prism layers are alternately arranged by the first structures and the second structures. Each cycle is 80 μm in length. The jitter amplitude V of the right-left jitter of the triangular prism rib is 10 μm. The foregoing technical solution includes embodiment 65.

Further, the prism layer is formed by tiling triangular prism ribs, and the triangular prism ribs are provided with a first structure and a second structure. The first structure and the second structure form a cycle. The prismatic layer includes a number of periods. The length of the base of the triangle of the cross section of the first structural triangular prism rib is 50 mu m, the angle of the vertex angle is 90 DEG, and the number of the triangular prism ribs in one period is 1, 2 or 3; the base of the triangle of the cross section of the second structural triangular prism rib is 35-50 μm in length, the angle of the apex angle is 80-105 degrees, and the number of the second structural triangular prism rib in one period is 2, 3, 4 or 6. That is, one cycle includes 1, 2, or 3 first structures and 2, 3, 4, or 6 second structures. Each cycle has a length of 120-450 μm. The jitter amplitude V of the left and right jitter of the triangular prism rib is 6-8 mu m. The foregoing technical solutions include examples 66-70.

Further, the prism layer is formed by tiling triangular prism ribs, and the triangular prism ribs are provided with a first structure, a second structure and a third structure. The first structure, the second structure, and the third structure form a cycle. The prismatic layer includes a number of periods. The jitter amplitude V of the left and right jitter of the triangular prism rib is 2-4 mu m.

Further, one cycle includes 2 or 3 first structures, 2, 3 or 4 second structures, and 2 or 3 third structures. The jitter amplitude V of the left and right jitter of the triangular prism rib is 2-4 mu m.

Further, one cycle includes 2 first structures, 2 second structures, and 2 third structures. The jitter amplitude V of the right-left jitter of the triangular prism rib is 4 μm.

Further, the base of the triangle is any t kinds of 30-80 mu m, t is 3, the vertex angle of the triangle is any k kinds of 75-105 degrees, and k is 3; the prism layer is formed by tiling three prism ribs, and the three prism ribs have a first structure, a second structure and a third structure. The first structure, the second structure, and the third structure form a cycle. The prismatic layer includes a number of periods. The jitter amplitude V of the left and right jitter of the triangular prism rib is 2-4 mu m.

Further, one cycle includes 2-3 (e.g., 2 or 3) first structures, 2-4 (2, 3, or 4) second structures, and 2-3 (e.g., 2 or 3) third structures. The jitter amplitude V of the left and right jitter of the triangular prism rib is 2-4 mu m.

Further, the prism layer is formed by tiling triangular prism ribs, and the triangular prism ribs are provided with a first structure, a second structure and a third structure. The first structure, the second structure, and the third structure form a cycle. The prismatic layer includes a number of periods. The base of the triangle of the cross section of the first triangular prism rib has a length of 50-80 μm (e.g., 50 μm or 80 μm), an angle of 90 ° at a vertex angle, and a number of 2-3 (e.g., 2 or 3) in one period; the base of the triangle of the cross section of the second triangular prism rib has a length of 30-60 μm (e.g., 30 μm, 35 μm, 40 μm, 50 μm, 55 or 60 μm), an angle of the apex angle of 75-85 ° (e.g., 75 °,80 °, or 85 °), and a number of 2-4, such as 2, 3 or 4, in one period. The length of the base of the triangle of the cross section of the third structural triangular rib is 40-60 μm (e.g., 40 μm or 60 μm), the angle of the apex angle is 95-105 ° (e.g., 95 °,100 °, or 105 °), and the number in one period is 2-3, e.g., 2 or 3. That is, one cycle includes 2-3 (e.g., 2 or 3) first structures, 2-4 (2, 3, or 4) second structures, and 2-3 (e.g., 2 or 3) third structures. Each cycle has a length of 240-600 μm. The jitter amplitude V of the left and right jitter of the triangular prism rib is 2-4 mu m. The foregoing technical solutions include examples 71-79.

The interference-relieving polarization-preserving composite prism film provided by embodiments 65 to 79 of the present invention has the upper substrate layer and the lower substrate layer both made of PC, the thickness T of 125 μm, the upper atomization layer made of a particle-free coating, the material AR, the refractive index of 1.5, the upper composite layer made of AR, the refractive index of 1.47, the prism layer made of AR, and the refractive index of 1.55. The haze of the underlying backcoatings of examples 65 to 70 was 30% and the haze of the underlying backcoatings of examples 71 to 79 was 5%. The haze of the upper atomizing layers of examples 65 to 76 was 95%, the haze of the upper atomizing layer of example 77 was 90%, the haze of the upper atomizing layer of example 78 was 80%, and the haze of the upper atomizing layer of example 79 was 60%. The polarization maintaining degree of the whole polarization maintaining composite prism films of examples 65 to 70 is 85%, the polarization maintaining degree of the whole polarization maintaining composite prism films of examples 71 to 76 is 87%, the polarization maintaining degree of the whole polarization maintaining composite prism film of example 77 is 92%, and the polarization maintaining degree of the whole polarization maintaining composite prism films of examples 78 and 79 is 94%.

Further, the prism layer is formed by tiling a triple prism rib, and the triple prism rib is provided with a first structure, a second structure, a third structure, a fourth structure, a fifth structure, a sixth structure and a seventh structure. The first, second, third, fourth, fifth, sixth and seventh structures form a cycle. The prismatic layer includes a number of periods.

Further, the number t of the bottom edges of the underlying prism layer is 7, the angle k is 1, the proportion s of the primary peak and the secondary peak is 2, the bottom edges of the first structure to the seventh structure are 65/60/55/50/45/40/35 μm respectively, the vertex angles are 90 degrees, the transverse period is 450 μm, 9 structures are arranged in the period, the number of the structures of the first structure (primary peak) is 3, the order is 1/4/7 (9 structures are arranged in one period), the number of the structures of the second structure to the seventh structure (secondary peak) is 1, and the order is 2/3/8/9/5/6 respectively. The underlying prism layer structure is provided with left-right dithering with a dithering amplitude V of 2 μm. The technical scheme includes an embodiment 80, and the overall polarization-preserving degree of the polarization-preserving composite prism film is 85%.

Further, the number t of the bottom edges is 1, the angle k is 7, the proportion s of the primary peak and the secondary peak is 2, the bottom edges of the first structure to the seventh structure are 50 μm, the vertex angles are 75/80/85/90/95/100/105 degrees respectively, the transverse period is 450 μm, 9 structures are arranged in the period, the number of the structures of the first structure (primary peak) is 3, the sequence is 1/4/7, the number of the structures of the second structure to the seventh structure (secondary peak) is 1, and the sequence is 2/3/8/9/5/6 respectively. The underlying prism layer structure is provided with left-right dithering with a dithering amplitude V of 2 μm. The foregoing technical solution includes embodiment 81. The polarization-preserving composite prism film provided in example 81 had a polarization-preserving degree of 85% overall.

When the linearly polarized light passes through the interference-reducing polarization-maintaining composite prism film, the polarization-maintaining degree of the interference-reducing polarization-maintaining composite prism film on the incident linearly polarized light is more than or equal to 85 percent.

Further, when the linearly polarized light in the LCD backlight passes through the interference-reducing polarization-preserving composite prism film, the polarized incident light can maintain a higher polarization degree, and the polarization-preserving degree is greater than or equal to 85%. Thereby ensuring the high transmission of the polarizer under the LCD and greatly improving the utilization rate of the backlight source.

The preparation method of the interference-eliminating polarization-preserving composite prism film comprises the following steps:

(1) Preparing a lower prism layer mold roller, an upper atomization layer mold roller and a lower back coating mold roller;

(2) Using the upper polarization-maintaining matrix layer as a supporting layer, and preparing an upper atomization layer on the front side by using an upper atomization layer mold roller through UV transfer printing to obtain an upper atomization semi-finished product only containing the upper atomization layer;

(3) And preparing the underlying back coating layer on the back surface by using an underlying back coating layer mold roller through UV transfer printing by taking the underlying polarization-preserving substrate layer as a supporting layer, so as to obtain an underlying back coating semi-finished product only containing the underlying back coating layer.

(4) Coating the back of the upper atomization semi-finished product with composite layer resin, preparing a lower prism layer on the front of the lower back coating semi-finished product by utilizing a lower prism layer mold roller through UV transfer printing, stacking and compositing two films up and down on line, and thoroughly combining (incapable of sliding) the two films through the UV curing process of the composite layer resin to finally obtain the interference-relieving polarization-preserving composite prism film.

The interference-removing polarization-preserving composite prism film provided by the invention can simultaneously realize the optical characteristics of interference removing and high polarization-preserving degree, and can keep higher incident light polarization degree when linearly polarized light in LCD backlight passes through the interference-removing polarization-preserving composite prism film, the polarization-preserving degree is not lower than 85%, the final high transmission of the polarizer under the LCD is ensured, and the utilization rate of the backlight source is further improved.

Drawings

FIG. 1 is a diagram showing the reason for low light energy utilization of LCD;

FIG. 2 is a schematic diagram of a conventional LCD enhancement scheme;

FIG. 3 is a schematic diagram of a novel LCD synergy scheme;

FIG. 4 is a graph showing the depolarization results of a conventional optical film in a novel synergistic optical path;

FIG. 5 is a schematic view of the polarization maintaining effect of the polarization maintaining optical film provided by the invention;

FIG. 6 is a schematic diagram of a method for testing polarization maintaining degree;

FIG. 7 is a schematic diagram of the basic structure of a polarization maintaining optical film;

FIG. 8 is a schematic diagram of the basic structure of the interference-canceling polarization-maintaining composite prism film of the present invention;

Fig. 9 is a top view (left-right shaking structure) of a lower prism layer structure of the interference-canceling polarization maintaining composite prism film of the present invention.

Wherein:

11: a polaroid is arranged on the upper surface of the substrate; 12: a liquid crystal panel (including a glass substrate, an optical filter, a liquid crystal layer, a thin film transistor, and the like); 13: a lower polarizer; 14: a backlight module; 15: a reflective polarizer;

21: partially polarized light; 22: linearly polarized light in a parallel direction (with respect to the lower polarizer transmission axis or plane of paper); 23: linearly polarized light in a vertical direction (with respect to the lower polarizer transmission axis or plane of paper);

3: a conventional optical film;

4: a polarization maintaining optical film;

50: a polarization-maintaining substrate layer; 51: a first structural layer; 52: a second structural layer;

60: a membrane to be measured; 61: a polarizer; 62: a parallel analyzer (parallel to the polarizer for detecting Imax); 63: vertical analyzer (perpendicular to polarizer, detect Imin).

70: A polarization-maintaining substrate layer is arranged on the upper part; 71: an upper structural layer (upper atomization layer); 72: a composite layer is arranged on the upper part;

80: a polarization-maintaining substrate layer is arranged below; 81: a lower structure layer (left-right dithering prism layer); 82: an underlying back coating;

81a: a peak of the left-right dithering prism; 81b: the trough of the prism is dithered left and right.

Detailed Description

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

The invention provides a polarization maintaining optical film (4), wherein the polarization maintaining optical film (4) is used for replacing a traditional optical film (3) in fig. 4, and as shown in fig. 5, after horizontally linearly polarized light (22) passes through the polarization maintaining optical film (4) provided by the invention, emergent light is kept as horizontally linearly polarized light (22).

The performance of the polarization maintaining optical film provided by the present invention was evaluated in the following manner.

(A) Degree of polarization conservation

As shown in fig. 6, a film (60) to be measured is placed above a polarizer (polarizer) (61), below a parallel analyzer (polarizer) 62 or a perpendicular analyzer (polarizer) 63, and the intensity of the outgoing light is measured. When the analyzer angle is parallel to the linear polarization, the analyzer is called a parallel analyzer, the light intensity is denoted Imax, when the analyzer angle is perpendicular to the linear polarization, the analyzer is called a perpendicular analyzer, the light intensity is denoted Imin, the polarization degree p= (Imax-Imin)/(imax+imin) of the light after passing through the film, P can be regarded as the polarization-preserving degree of the film for the linear polarization as well.

As shown in fig. 7, the present invention provides a polarization maintaining optical film, which includes a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is located on the upper surface of the polarization maintaining substrate layer 50, and the second structural layer is located on the lower surface of the polarization maintaining substrate layer 50.

Example 1

The present invention provides a polarization maintaining optical film, as shown in fig. 7, wherein the polarization maintaining optical film is a polarization maintaining diffusion film, the first structural layer 51 is an atomized layer DL (Diffusion layer), and the second structural layer 52 is absent. The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy, polarization-preserving degree is >99%, and the haze of the polarization-preserving diffusion film is 98%. The first atomization layer has a haze of 98%, the atomization layer is a particle coating and consists of transparent polymer resin PU and transparent polymer particles PMMA, the particle size d is 5-15 mu m, and the refractive index na of the transparent polymer resin is 1.5. The polarization-preserving degree of the polarization-preserving diffusion film is 82%.

Example 2

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining diffusion film, the first structural layer 51 is an atomization layer, and the second structural layer 52 is an atomization layer. The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy, polarization-preserving degree is >99%, and the haze of the polarization-preserving diffusion film is 98%. The first atomization layer has a haze of 98%, the atomization layer is a particle coating and consists of transparent polymer resin PU and transparent polymer particles PMMA, the particle size d is 5-15 mu m, and the refractive index na of the transparent polymer resin is 1.5. The haze of the second atomization layer is 5%, the atomization layer is a particle-free coating and is composed of transparent polymer resin AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization-preserving degree of the polarization-preserving diffusion film is 80%.

Examples 3 to 20

The polarization maintaining diffusion film as provided in example 1, and the other parameters are listed in table 1.

TABLE 1 design parameters and optical Properties of polarization-preserving diffusion films provided in examples 1-20

Note 1: t is the thickness of the polarization-maintaining substrate layer.

As shown in table 1, examples of polarization maintaining diffusion films with different materials and design parameters are shown. It can be found that when the substrate layer is made of the polarization-maintaining substrate such as PC, PMMA, TAC, COP, the polarization-maintaining degree of the prepared polarization-maintaining diffusion film is more than 80%, and the influence of the thickness T is not great. When the haze of the atomized layer is reduced, the polarization maintaining degree is improved, and the type of the atomized layer, resin and particle materials have little influence on the atomized layer. When the second structural layer is an atomization layer with low haze, the anti-sticking and scratch-resistant effects can be achieved, and the optical influence is small.

Example 21

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining microlens film, the first structural layer 51 is a microlens array layer ML (Microlens layer), and the second structural layer 52 is not present. The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy, polarization-preserving degree is >99%, and the haze of the polarization-preserving micro lens film is 96%. The haze of the microlens array layer was 98%, and the microlens array layer was formed of a transparent polymer resin AR having a refractive index nc of 1.5. In the microlens array layer, the distance D between the main optical axes of adjacent microlenses is 50 μm, the width of the microlens is W (W=D), the height of the microlens is H, and the height-width ratio H/W is 0.5, and at this time, the microlens is hemispherical; the polarization maintaining degree of the polarization maintaining micro lens is 85%.

Example 22

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining microlens film, the first structural layer 51 is a microlens array layer, and the second structural layer 52 is an atomization layer. The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-preserving substrate layer is selected from PC, optical isotropy, polarization-preserving degree is >99%, and the haze of the polarization-preserving micro lens film is 96%. The haze of the microlens array layer was 98%, and the microlens array layer was composed of a transparent polymer resin AR having a refractive index nc of 1.5. The haze of the atomization layer is 5%, the atomization layer is a particle-free coating and consists of a transparent polymer AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization-preserving degree of the polarization-preserving micro-lens film is 85%.

Examples 23 to 36

The polarization maintaining microlens film as provided in example 21, the other parameters are listed in table 2.

Table 2 design parameters and optical properties for examples 21-36

Note 1: t is the thickness of the substrate layer; d is the distance between the main optical axes of adjacent microlenses; w is the width of the microlens, H is the height of the microlens, and H/W is the aspect ratio.

As shown in table 2, examples of polarization maintaining microlens films with different materials and design parameters are shown. It can be found that when the substrate layer is made of the polarization-preserving substrate such as PC, PMMA, TAC, COP, the polarization-preserving degree of the prepared polarization-preserving microlens film is more than 80%, and the influence of the thickness T is not great. When the haze of the microlens layer is reduced, the polarization-preserving degree is increased, and when the refractive index of the transparent polymer is reduced, or the aspect ratio is reduced, the haze is also reduced, the polarization-preserving degree is also increased, and the influence of the kind of resin is not great. When the second structural layer is an atomization layer with low haze, the anti-sticking and scratch-resistant effects can be achieved, and the optical influence is small.

Example 37

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining prism film, the first structural layer 51 is a prism layer PL (Prism layer), and the second structural layer 52 is not present. The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-maintaining substrate layer is selected from PC, optical isotropy, and polarization-maintaining degree is >99%, the prism layer is composed of transparent polymer resin AR, and the refractive index nd of the transparent polymer resin is 1.55. The prism layer is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom edges of the triangles are 50 mu m, and the vertex angles are 90 degrees. The polarization maintaining degree of the polarization maintaining prism film is 98%.

Example 38

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining prism film, the first structural layer 51 is a prism layer PL (Prism layer), and the second structural layer 52 is an atomization layer. The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-maintaining substrate layer is selected from PC, optical isotropy, and polarization-maintaining degree is >99%, the prism layer is composed of transparent polymer resin AR, and the refractive index nd of the transparent polymer resin is 1.55. The prism layer is formed by tiling triangular prism ribs, the cross sections of the triangular prism ribs are isosceles triangles, the bottom edges of the triangles are 50 mu m, and the vertex angles are 90 degrees. The haze of the atomization layer is 5%, the atomization layer is a particle-free coating and consists of a transparent polymer AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization maintaining degree of the polarization maintaining prism film is 97%.

Examples 39 to 50

The polarization maintaining prism film as provided in example 37, and the other parameters are listed in table 3.

TABLE 3 design parameters and optical Properties for examples 37-50

Note 1: t is the thickness of the substrate layer.

As shown in table 3, examples of polarization maintaining prism films with different materials and design parameters are shown. It can be found that when the substrate layer is made of the polarization-maintaining substrate such as PC, PMMA, TAC, COP, the polarization-maintaining degree of the prepared polarization-maintaining prism film is more than 80%, and the influence of the thickness T is not great. When the material, refractive index, bottom edge and top angle of the prism layer are changed, the polarization-preserving degree is basically not affected. When the second structural layer is an atomization layer, the effects of anti-sticking and anti-scraping can be achieved, and when the haze is increased, the polarization maintaining degree is slightly reduced.

Example 51

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining inverse prism film, the first structural layer 51 is not present, and the second structural layer 52 is an inverse prism layer RL (Rverse-PRISM LAYER). The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-maintaining substrate layer is selected from PC, optical isotropy, and polarization-maintaining degree is >99%, the inverse prism layer is composed of transparent polymer resin AR, and the refractive index nd of the transparent polymer resin is 1.55. The inverted prism layer is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle or a common triangle, the width L of the bottom edge of each triangle is 50 mu m, the vertex angle theta is 60 degrees, one larger bottom angle alpha is 90 degrees to 0.5θ+gamma, and the deflection angle gamma is 0 degrees. The polarization maintaining degree of the polarization maintaining inverse prism film is 98%.

Example 52

As shown in fig. 7, the polarization maintaining optical film provided by the invention comprises a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, wherein the first structural layer is positioned on the upper surface of the substrate layer 50, the second structural layer is positioned on the lower surface of the substrate layer 50, the polarization maintaining optical film is a polarization maintaining inverse prism film, the first structural layer 51 is an atomization layer, and the second structural layer 52 is an inverse prism layer RL (Rverse-PRISM LAYER). The thickness T of the substrate layer 50 is 250 μm, the material of the polarization-maintaining substrate layer is selected from PC, optical isotropy, and polarization-maintaining degree is >99%, the inverse prism layer is composed of transparent polymer resin AR, and the refractive index nd of the transparent polymer resin is 1.55. The inverted prism layer is formed by tiling triangular prism ribs, the cross section of each triangular prism rib is an isosceles triangle, the width L of the bottom edge of the triangle is 50 mu m, the vertex angle theta is selected from 60 degrees, one larger bottom angle alpha is 90 degrees to 0.5θ+gamma, and the deflection angle gamma is 0 degrees. The haze of the atomization layer is 30%, the atomization layer is a particle-free coating and consists of a transparent polymer AR, and the refractive index nb of the transparent polymer resin is 1.5. The polarization maintaining degree of the polarization maintaining prism film is 95%.

Examples 53 to 64

The polarization maintaining inverse prism film as provided in example 51, and the other parameters are listed in table 4.

TABLE 4 design parameters and optical Properties for examples 51-64

Note 1: t is the thickness of the substrate layer.

As shown in table 4, examples of polarization maintaining inverse prism films with different materials and design parameters are shown. It can be found that when the substrate layer is made of the polarization maintaining substrate such as PC, PMMA, TAC, COP, the polarization maintaining degree of the prepared polarization maintaining inverse prism film is more than 80%, and the influence of the thickness T is not great. When the material, refractive index, bottom edge and top angle of the inverse prism layer are changed, the polarization maintaining degree is basically not affected. When the first structural layer is an atomization layer, the effects of anti-sticking and scratch resistance can be achieved, and when the haze is increased, the polarization maintaining degree is slightly reduced.

Examples 65 to 79

As shown in fig. 8, the interference-reducing polarization-preserving composite prism film provided in examples 65 to 79 is characterized in that the upper substrate layer and the lower substrate layer are both made of PC, the thickness T is 125 μm, the upper atomization layer is a particle-free coating layer, the material is AR, the refractive index is 1.5, the upper composite layer is AR, the refractive index is 1.47, the prism layer is AR, and the refractive index is 1.55. The haze of the underlying backcoatings of examples 65 to 70 was 30% and the haze of the underlying backcoatings of examples 71 to 79 was 5%. The haze of the upper atomizing layers of examples 65 to 76 was 95%, the haze of the upper atomizing layer of example 77 was 90%, the haze of the upper atomizing layer of example 78 was 80%, and the haze of the upper atomizing layer of example 79 was 60%. The polarization maintaining degree of the whole polarization maintaining composite prism films of examples 65 to 70 is 85%, the polarization maintaining degree of the whole polarization maintaining composite prism films of examples 71 to 76 is 87%, the polarization maintaining degree of the whole polarization maintaining composite prism film of example 77 is 92%, and the polarization maintaining degree of the whole polarization maintaining composite prism films of examples 78 and 79 is 94%. The other prism layer structure design parameters described in examples 65-79 are set forth in Table 5.

Example 80

In example 65, the design of the substrate layer, the upper atomization layer, the upper composite layer, and the lower back coating layer of the interference-canceling polarization-maintaining composite prism film provided in example 80 is the same as that of example 65, the structural design of the lower prism layer is different, wherein the number t of bottom edges is 7, the angle k is 1, the proportion s of main and sub peaks is 2, the bottom edges of the first structure to the seventh structure are 65/60/55/50/45/40/35 μm respectively, the vertex angles are 90 ° respectively, the transverse period is 450 μm, and 9 structures are all arranged in the period, wherein the number of structures of the first structure (main peak) is 3, the order is 1/4/7 (9 structures are all arranged in one period), the number of structures of the second structure to the seventh structure (sub peak) is 1, and the order is 2/3/8/9/5/6 respectively. The underlying prism layer structure is provided with left-right dithering with a dithering amplitude V of 2 μm. The polarization maintaining composite prism film provided in example 80 has an overall polarization maintaining degree of 85%.

Example 81

In example 65, the design of the substrate layer, the upper atomization layer, the upper composite layer, and the lower back coating of the interference-canceling polarization-maintaining composite prism film provided in example 81 is the same as that of example 65, the structural design of the lower prism layer is different, the number t of bottom edges is 1, the angle k is 7, the proportion s of main and sub peaks is 2, the bottom edges of the first structure to the seventh structure are 50 μm, the vertex angles are 75/80/85/90/95/100/105 ° respectively, the transverse period is 450 μm, and the total number of 9 structures are in the period, wherein the number of structures of the first structure (main peak) is 3, the order is 1/4/7, the number of structures of the second structure to the seventh structure (sub peak) is 1, and the order is 2/3/8/9/5/6 respectively. The underlying prism layer structure is provided with left-right dithering with a dithering amplitude V of 2 μm. The polarization-preserving composite prism film provided in example 81 had a polarization-preserving degree of 85% overall.

When the bottom edges are consistent, the smaller the top angle is, the higher the prism is; when the vertex angles are consistent, the larger the bottom edge is, the higher the prism is; in both examples, the first structure is the main peak.

Table 5 prism layer design parameters for examples 65-79 polarization maintaining composite prism films

Note 1: the sequence represents an arrangement order of the first structure, the second structure, or the third structure from left to right in the entire period.

With comparative examples 65 to 70, 80, 81, and comparative examples 71 to 76, the polarization maintaining degree of the polarization maintaining composite prism film was not substantially affected when only the structural design of the underlying prism layer was changed. The interference-resolving polarization-preserving composite prism film is obtained through the special design collocation of the top angle and the bottom edge of the prism structure (cross-section triangle), and the optical characteristics of interference resolution and high polarization-preserving degree can be simultaneously realized. Through the collocation design of the major peak, the minor peak, the height, and the like, the sufficient binding force and the structure confusion degree (interference elimination effect) are ensured, and the collocation proportion s is preferably 2. In the same period, 1-7 base types t and top angles k are selected, preferably 2-3 base types t and top angles k are selected, less than 2 types of interference solving weaknesses are weak, more than 3 types of cutters are selected, and the processing cost is high. In comparative examples 76 to 79, the lower the haze of the upper atomization layer, the higher the polarization-maintaining degree of the polarization-maintaining composite prism film, and the 60% haze of the atomization layer can realize non-corner interference due to the strong enough interference eliminating capability of the prism. When the structure is simple, larger jitter amplitude can be matched, such as 4-10 mu m, and when the structure is complex, smaller jitter amplitude can be matched, such as 1-4 mu m. When the jitter amplitude is less than 2 μm, the film surface is fine but the interference removing effect is weak, and when the jitter amplitude is more than 4 μm, the interference removing effect is strong but the film surface is rough, and the film surface is preferably 2-4 μm in general. It should be noted that the amplitude of the side-to-side jitter should also be smaller than the bottom width W _min of the smallest prism rib in the periodic structure, otherwise staggering of the prism ribs would occur, which is detrimental to the appearance.

It should be noted that the above descriptions are only exemplary embodiments of the invention and are not intended to limit the scope of the invention. All equivalent changes and modifications made in accordance with the present invention are intended to be covered by the scope of the appended claims.

Claims

1. The interference-removing polarization-preserving composite prism film is characterized by comprising an upper polarization-preserving substrate layer, an upper structure layer, an upper composite layer, a lower polarization-preserving substrate layer, a lower structure layer and a lower back coating. The upper structure layer is positioned on the upper surface of the upper polarization-preserving substrate layer, and the upper composite layer is positioned on the lower surface of the upper substrate layer; the lower structure layer is a left-right shaking prism layer and is positioned on the upper surface of the lower polarization-preserving substrate layer, and the lower back coating is positioned on the lower surface of the lower substrate layer; the left and right shaking prism layers are formed by tiling a plurality of identical or different triangular prism ribs; the triangular prism ribs shake left and right along the longitudinal direction; the resin of the upper composite layer is combined with the peak tip of the lower prism layer after being solidified; the ridge line of the triangular prism rib is a free curve of left-right jitter variation; the upper substrate layer and the lower substrate layer are both made of PC, the thickness T is 125 mu m, the upper atomization layer is a particle-free coating, the material is AR, the refractive index is 1.5, the material of the upper composite layer is AR, the refractive index is 1.47, the material of the prism layer is AR, the refractive index is 1.55, and the haze of the lower back coating is 30%; the number t of the bottom edges in the underlying prism layer is 1, the angle k is 7, the proportion s of the primary and secondary peaks is 2, the bottom edges of the first structure to the seventh structure are 50 mu m, the vertex angles are 75/80/85/90/95/100/105 degrees respectively, the transverse period is 450 mu m, 9 structures are arranged in the period, wherein the number of the primary peaks of the first structure is 3, the sequence is 1/4/7, the number of the secondary peaks of the second structure to the seventh structure is 1, and the sequence is 2/3/8/9/5/6 respectively; the underlying prism layer structure is provided with left-right dithering with a dithering amplitude V of 2 μm.