CN114114509B - Polarization-preserving optical film, interference-relieving polarization-preserving micro-lens film and preparation method thereof - Google Patents

Polarization-preserving optical film, interference-relieving polarization-preserving micro-lens film and preparation method thereof Download PDF

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CN114114509B
CN114114509B CN202111011848.0A CN202111011848A CN114114509B CN 114114509 B CN114114509 B CN 114114509B CN 202111011848 A CN202111011848 A CN 202111011848A CN 114114509 B CN114114509 B CN 114114509B
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polarization
layer
maintaining
film
preserving
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CN114114509A (en
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夏寅
余洋
赵国林
付坤
陈建文
李刚
唐海江
张彦
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Ningbo Exciton Technology Co Ltd
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Ningbo Exciton Technology Co Ltd
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    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/30Polarising elements
    • G02B5/3025Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid
    • G02B5/3041Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks
    • G02B5/305Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state in the form of a thin sheet or foil, e.g. Polaroid comprising multiple thin layers, e.g. multilayer stacks including organic materials, e.g. polymeric layers
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00Simple or compound lenses
    • G02B3/0006Arrays
    • G02B3/0012Arrays characterised by the manufacturing method
    • G02B3/0031Replication or moulding, e.g. hot embossing, UV-casting, injection moulding
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B3/00Simple or compound lenses
    • G02B3/0006Arrays
    • G02B3/0037Arrays characterized by the distribution or form of lenses
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • GPHYSICS
    • G02OPTICS
    • G02FOPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • G02F1/133607Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A90/00Technologies having an indirect contribution to adaptation to climate change
    • Y02A90/10Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

The invention relates to a polarization-maintaining optical film, in particular to a polarization-maintaining optical film applied to an LCD linear polarization backlight source, a interference-eliminating polarization-maintaining micro lens film and a preparation method thereof. The invention provides a de-interference polarization-preserving micro-lens 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 polarization-maintaining micro-lens film comprises a polarization-maintaining substrate layer, a first structural layer and a second structural layer, wherein the first structural layer is a random micro-lens array layer and is positioned on the upper surface of the substrate layer, and the second structural layer is not present or is an atomization layer and is positioned on the lower surface of the substrate layer. In the random microlens array layer, coordinates of main optical axes of adjacent three microlenses are connected to form a common triangle, the distance between the main optical axes of the adjacent microlenses is randomly changed within a certain value range, and the height-width ratio is randomly changed within a certain value range. The linearly polarized light in the LCD backlight can retain a higher degree of polarization of the incident light when passing through the polarization maintaining microlens film.

Description

Polarization-preserving optical film, interference-relieving polarization-preserving micro-lens film and preparation method thereof
Technical Field
The invention relates to a polarization maintaining optical film, in particular to a polarization maintaining optical film applied to an LCD linear polarization backlight source, a de-interference polarization maintaining micro lens film and a preparation method thereof.
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 material of the atomization layer is selected from one of AR (Acrylic resin or modified Acrylic resin), PMMA (polymethyl methacrylate), PC (polycarbonate) 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%).
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 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 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 not present. The thickness T of the substrate layer is 25-250 μm (e.g. 25-250 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 (e.g. 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 present 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 (reverse-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, optical isotropy and polarization-preserving degree is >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). 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;
further, the preparation method of the polarization-preserving optical film comprises the following steps:
(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;
further, the preparation method of the polarization-preserving optical film comprises the following steps:
(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;
further, the preparation method of the polarization-preserving optical film comprises the following steps:
(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; the method comprises the steps of carrying out a first treatment on the surface of the
Further, the preparation method of the polarization-preserving optical film comprises the following steps:
(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;
further, the preparation method of the polarization-preserving optical film comprises the following steps:
(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 polarization point light source for design, so that a linear polarization backlight source can be conveniently generated, a reflective polarizer with complex process and high price is not needed, the high transmission of the polarizer under an LCD (liquid crystal display) 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.
In order to further improve the polarization maintaining performance of the complex backlight structure with multiple stacked films, the polarization maintaining performance of each polarization maintaining optical film needs to be improved as much as possible, otherwise, the polarization maintaining performance of the complex backlight structure is obviously reduced. In this regard, the invention provides a further optimization scheme for improving the polarization maintaining performance of the single Zhang Mopian film on the premise of not losing the original optical function of the polarization maintaining optical film so as to adapt to a complex backlight architecture.
It is found that, although the microlens film generally has higher haze and similar diffusion light homogenizing effect, the microlens film is placed above the prism to help to release the interference between the prism and the panel, however, the microlens array of the conventional microlens film is regularly arranged, and each microlens has the same structure, so that the microlens film is easy to interfere with the panel with high resolution, and corner cutting is required.
In order to solve the interference problem of the microlens film, it is necessary to develop a de-interference microlens film that randomly changes the arrangement and microlens structure within a certain range. And in order to balance the light homogenizing effect and polarization maintaining performance of the polarization maintaining microlens film, coverage rate and aspect ratio of the polarization maintaining microlens film need to be further limited.
The invention provides a de-interference polarization-maintaining micro-lens film, which comprises a polarization-maintaining substrate layer, a first structural layer and a second structural layer; the first structural layer is a random microlens array layer and is positioned on the upper surface of the substrate layer; the second structural layer is not present or is an atomized layer and is positioned on the lower surface of the substrate layer.
In the random microlens array layer, coordinates of main optical axes of adjacent three microlenses are connected to form a common triangle, and the distance D between the main optical axes of the adjacent microlenses is randomly changed within a certain value range. The general triangle means a triangle other than a right triangle, an isosceles triangle, and an equilateral triangle.
In the random microlens array layer, the width W (caliber) of the microlenses randomly changes within a certain value range.
In the random microlens array layer, the aspect ratio B (b=h/W) of the microlenses randomly changes within a certain range of values.
In the random microlens array layer, the plane coverage rate C of the random microlens array is 80% -95% (100% can not be achieved because of being incapable of being closely arranged).
The haze of the random microlens array layer is 60-90%. Further, the haze of the random microlens array layer is 60 to 87%.
In the random microlens array layer, the distance between the main optical axes of adjacent microlenses is randomly changed, and the change range is D min ~D max ,10μm≤D min <D max Less than or equal to 50 mu m; the width of the micro lens is randomly changed, and the change range is W min ~W max ,10μm≤W min <W max Less than or equal to 50 mu m; the aspect ratio of the micro lens is randomly changed, and the change range is B min ~B max ,0.1≤B min <B max ≤0.3。
The haze of the interference-eliminating polarization-preserving micro lens film is 60-90%.
Further, in the random microlens array layer, the main optical axis spacing of adjacent microlenses is randomly changed, and the change range is 10 μm-50 μm; the width of the micro lens is randomly changed, and the change range is 10-50 mu m; the aspect ratio of the micro lens is randomly changed, and the change range is 0.1-0.3 or 0.1-0.2. Further, the haze of the interference-eliminating polarization-maintaining micro-lens film is 60-87%. The foregoing technical solutions include examples 69-71 and examples 74-80.
Further, the substrate layer is selected from one of PC, TAC, PMMA and COP, and has a thickness T of 25-250 μm, for example 250, 125, 100, 50, or 25 μm.
The random microlens array layer is composed of a transparent polymer resin AR having a refractive index nc of 1.5 to 1.6.
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 haze of the atomized layer was 5%.
When the linearly polarized light passes through the interference-reducing polarization-maintaining micro-lens film, the polarization-maintaining degree of the interference-reducing polarization-maintaining micro-lens film on the incident linearly polarized light is more than or equal to 90 percent.
Further, when the linearly polarized light in the LCD backlight passes through the interference-reducing polarization-preserving microlens film, the polarized incident light can maintain a higher polarization degree, and the polarization-preserving degree is greater than or equal to 93%. 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 micro lens film comprises the following steps:
(1) Mold roll for preparing random microlens array layer
(2) Preparing a random microlens array layer on the front side by using a die roller through UV transfer printing by taking the polarization-preserving matrix layer as a supporting layer to obtain a de-interference polarization-preserving microlens film only containing the front-side random microlens array layer;
further, the preparation method of the interference-eliminating polarization-preserving micro lens film comprises the following steps:
(1) Coating an atomization layer on the back of the polarization-maintaining substrate layer serving as a supporting layer to obtain a polarization-maintaining back-coating semi-finished product containing the atomization layer;
(2) Preparing a mold roll of the random microlens array layer;
(3) And preparing a random microlens array layer on the front side of the polarization-preserving back-coated semi-finished product (namely, the front side of the polarization-preserving substrate layer) by utilizing a die roller through UV transfer printing to obtain the interference-relieving polarization-preserving microlens film simultaneously containing a back atomization layer and the front random microlens array layer.
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. 8a is a schematic diagram of the basic structure of a de-interference polarization-maintaining microlens film of the present invention (a fully random microlens array layer, without a backside haze layer);
FIG. 8b is a schematic diagram of the basic structure of a de-interference polarization maintaining microlens film of the present invention (a fully random microlens array layer, containing a backside haze layer);
FIG. 9 is a three-dimensional schematic view of a regular microlens array layer of a conventional polarization maintaining microlens film of the present invention;
FIG. 10 is a three-dimensional schematic of a fully random microlens array layer of the interference-canceling polarization maintaining microlens 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;
54: a particle-free atomization layer; 56: a regular microlens array layer; 59: full random microlens array 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).
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 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 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
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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, for example PC, PMMA, TAC, COP, the polarization-maintaining degree of the prepared polarization-maintaining diffusion film is greater 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 96%, 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 96%, 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
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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, for example 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, for example PC, PMMA, TAC, COP, the polarization maintaining degree of the prepared polarization maintaining prism film is greater 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 present invention includes a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, where the first structural layer is located on the upper surface of the substrate layer 50, the second structural layer is located 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 (reverse-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 present invention includes a first structural layer 51, a polarization maintaining substrate layer 50 and a second structural layer 52, where the first structural layer is located on the upper surface of the substrate layer 50, the second structural layer is located 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 (reverse-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, for example PC, PMMA, TAC, COP, the polarization maintaining degree of the prepared polarization maintaining inverse prism film is greater 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 74
As in example 21, the interference-reducing polarization-maintaining microlens films provided in comparative examples 1 to 4 and examples 65 to 74 were PC as the material of the base layer, 250 μm as the thickness T, AR as the material of the random microlens array layer, and 1.5 as the refractive index. Among these, comparative examples 1 to 4 and examples 65 to 73 were free of a back surface atomizing layer (as shown in FIG. 8 a), and example 74 was free of an atomizing layer (as shown in FIG. 8 b), the atomizing layer was a particle-free coating layer having a haze of 5%, the particle-free coating layer was AR, and the refractive index was 1.5. Comparative examples 1 to 4 have poor interference effect, 85 to 97% polarization maintaining degree, examples 65 to 68 and 72 to 73 have good interference effect, 90 to 97% polarization maintaining degree, and examples 69 to 71 have excellent interference effect and 93 to 98% polarization maintaining degree. The structural design parameters of the other interference-canceling polarization maintaining microlens films described in comparative examples 1 to 4 and 65 to 74 are shown in Table 5.
Examples 75 to 80
In example 21, the interference-reducing polarization-preserving microlens films of examples 75 to 80 were prepared from one of PC, TAC, PMMA, COP as the base layer material, 125, 100, 50, and 25 μm as the thickness T, AR as the random microlens array layer material, and 1.5 as the refractive index. Examples 75 to 80 had no back side atomizing layer (as shown in FIG. 8 a), and examples 75 to 80 had excellent interference cancellation effect and polarization maintaining degree of 95%. The design parameters of the interference-canceling polarization maintaining microlens film structures of examples 75 to 80 are shown in Table 5.
Table 5 design parameters and properties of the polarization maintaining microlens films provided in examples 65 to 80 and comparative examples 1 to 4
Note 1: t is the thickness of the substrate layer; d (D) min /D max The lower limit/upper limit of the value range of random change of the distance between the main optical axes of the adjacent microlenses is respectively; w (W) min /W max The lower limit/upper limit of the value range of random variation of the width of the micro lens is respectively; b (B) min /B max The lower limit/upper limit of the value range of random change of the height-width ratio of the micro lens is respectively; c is the planar coverage of the microlens array.
As shown in table 5, examples and comparative examples of polarization-maintaining microlens films with different materials and design parameters were prepared, wherein comparative examples 1 to 4 were common polarization-maintaining microlens films, and were structured in regular equal height, D was identical to W, the aspect ratio was a constant value, the higher the haze was the greater the aspect ratio, the lower the polarization-maintaining degree was, and the coverage rate C was 100% due to the close arrangement of the regular structure, but the interference-resolving power of the regular structure was poor. Examples 65-73 are interference-solving polarization-preserving microlens films with different design parameter combinations, and it can be found that the more random microlens arrays are disordered, the better the interference-solving ability is (examples 69-71) when the random variation range of D/W/B is larger. In addition, when the random variation range is the same, different coverage rates can be designed according to the requirement, and different optical effects such as haze, polarization maintaining degree and the like can be obtained, but the interference resolving power is basically consistent (as in examples 69-70). In addition, comparative examples 70, 74 showed that the low haze back coating had little effect on the overall optical effect, and comparative examples 70, 75-80 showed that the base layer materials and thickness had little effect on the performance.
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 (4)

1. The interference-eliminating polarization-maintaining micro-lens film is characterized by comprising a polarization-maintaining substrate layer, a first structural layer and a second structural layer; the first structural layer is a random microlens array layer and is positioned on the upper surface of the substrate layer; the second structural layer is not present or is an atomization layer and is positioned on the lower surface of the matrix layer; in the random microlens array layer, the main optical axis distance of adjacent microlenses is randomly changed, and the change range is 10-50 mu m; the width of the micro lens is randomly changed, and the change range is 10-50 mu m; the aspect ratio of the micro lens is randomly changed, and the change range is 0.1-0.3.
2. The interference-reducing polarization-maintaining microlens film according to claim 1, wherein the aspect ratio of the microlens varies in the range of 0.1 to 0.2.
3. The interference-solving polarization-preserving microlens film according to claim 1 or 2, wherein the plane coverage rate C of the random microlens array in the random microlens array layer is 80% to 95%.
4. The interference-solving polarization-preserving microlens film according to claim 1 or 2, wherein the haze of the random microlens array layer is 60 to 87%. The haze of the atomized layer was 5%.
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