WO2006014041A1 - Broadband reflective polarizer for liquid crystal display using overcoating method - Google Patents

Broadband reflective polarizer for liquid crystal display using overcoating method Download PDF

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Publication number
WO2006014041A1
WO2006014041A1 PCT/KR2004/003013 KR2004003013W WO2006014041A1 WO 2006014041 A1 WO2006014041 A1 WO 2006014041A1 KR 2004003013 W KR2004003013 W KR 2004003013W WO 2006014041 A1 WO2006014041 A1 WO 2006014041A1
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WO
WIPO (PCT)
Prior art keywords
liquid crystal
cholesteric liquid
film
laminated
polarizing plate
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PCT/KR2004/003013
Other languages
French (fr)
Inventor
Sung-Tae Kim
Keon-Il Kim
Original Assignee
Samsung Fine Chemicals Co.,Ltd
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Publication date
Application filed by Samsung Fine Chemicals Co.,Ltd filed Critical Samsung Fine Chemicals Co.,Ltd
Priority to US10/587,559 priority Critical patent/US7486376B2/en
Publication of WO2006014041A1 publication Critical patent/WO2006014041A1/en

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Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL 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
    • G02F1/00—Devices 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
    • G02F1/01—Devices 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 
    • G02F1/13—Devices 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
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528—Polarisers
    • G02F1/133536—Reflective polarizers
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL 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
    • G02F1/00—Devices 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
    • G02F1/01—Devices 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 
    • G02F1/13—Devices 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
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • G02B5/3025—Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state
    • G02B5/3033—Polarisers, 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
    • G02B5/3041—Polarisers, 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
    • G02B5/305—Polarisers, 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
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
    • C09K2323/03—Viewing layer characterised by chemical composition
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL 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
    • G02F1/00—Devices 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
    • G02F1/01—Devices 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 
    • G02F1/13—Devices 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
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133528—Polarisers
    • G02F1/133543—Cholesteric polarisers
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL 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
    • G02F2203/00—Function characteristic
    • G02F2203/05—Function characteristic wavelength dependent

Definitions

  • the present invention relates to a method of fabrication of a reflective polarizing film for a liquid crystal display device, in which cholesteric liquid crystal layers having selective light-reflection central wavelengths different from one another are laminated in the laminated coating method, thus forming a liquid crystal film that covers a visible light region, and a quarter wave (1/4 ⁇ ) retardation film is attached on the top of the liquid crystal film.
  • a liquid crystal display (LCD) device that has been used typically employs a polarizing film using linearly polarized light.
  • the polarizing film is fabricated by adsorbing an iodine or dichroic dye on a polyvinyl alcohol (PVA) film to form a resulting adsorbed film and stretching the resulting adsorbed film in a certain direction.
  • PVA polyvinyl alcohol
  • the polarizing film fabricated thus cannot be used as a practical polarizing film since its mechanical strength is weak with respect to the direction of a transmission axis and a polarizing function is significantly degraded due to shrinkage by heat or moisture.
  • a polarizing film having a structure in which an adhesive is adhered between supports such as an acetic acid cellulose film, etc. has been developed.
  • the polarizing film using the above-described polyvinyl alcohol film produces linearly polarized light by absorbing light that progresses in one direction while passing only light that vibrates in the other direction.
  • efficiency of the polarizing film does not exceed 50% theoretically, which acts as the most significant factor to reduce the efficiency and brightness of an LCD.
  • a reflective polarizing film formed by using cholesteric liquid crystal is additionally used, the shortcomings of the conventional polarizing films can be improved greatly.
  • Cholesteric liquid crystals have a selective reflection characteristic in which a twisted direction of a spiral liquid crystal structure and an oriented direction of a circularly polarized light are consistent with each other and only a circularly polarized light of which wavelength is the same as the spiral pitch of the liquid crystal is reflected. If the selective reflection characteristic is employed, it is possible to fabricate a polarizing film that converts non-polarized light of a constant wavelength band into a specific circularly polarized light.
  • the polarizing film formed by using the cholesteric liquid crystal film is employed additionally, brightness can be improved significantly compared to the case in which only a conventional absorption type polarizing film that absorbs 50% light is used because there is no loss of light theoretically.
  • a backlight- used in an LCD usually generates light of a visible band (400 to 700 nm) that is a region where colors are displayed. Therefore, the selective reflection wavelength region of the cholestric liquid crystal film has to cover the visible light region. If the selective reflection wavelength region of the cholestric liquid crystal film does not cover the visible light region, light of a certain wavelength which is not selectively reflected get into the polarizing film in a non- polarizing state. Accordingly, there is a problem that the picture quality of the LCD is degraded.
  • the present invention is provided in order to solve the above problems, and it is an object of the present invention to provide a method of manufacturing a broadband reflective polarizing film for a liquid crystal display device using a laminated coating method in which brightness is improved remarkably compared to that of the conventional polarizing films.
  • cholestric liquid crystal layers having selective light-reflecting central wavelengths different from one another are laminated in the laminated coating method to form a liquid crystal film that covers a visible ray.
  • Orientation layers are coated between the liquid crystal layers one by one, thus improving the optical properties of cholestric liquid crystals to the maximum.
  • FIG. 1 is a cross-sectional view showing the structure of a film according to the present invention.
  • FIG. 2 is a cross-sectional view showing the structure of a liquid crystal display according to the present invention.
  • a cholestric liquid crystal film that is formed by dissolving a curable cholesteric liquid crystal material and a photoinitiator in an organic solvent, coating them on a substrate and curing or polymerizing by irradiating the mixed material with UV.
  • the cholesteric liquid crystal material is composed of a curable nematic liquid crystal material and a curable chiral material. It is possible to control a selective light-reflecting central wavelength depending on the composition of the two materials.
  • the curable nematic liquid crystal material can be used if they are liquid crystal materials containing a mesogenic radical group representing a nematic liquid crystal. If a chiral material is a material having typical chiral carbons, it can be used. Thus, they are not limited to specific materials. In the present invention, any material which contains a thermal or ultraviolet reactive group in its molecular structure is acceptable for a curable material.
  • a combination of monomers having an alkenyl radical such as a vinyl radical, an acrylic radical, a methacrylic radical, a vinylidene radical, an aryl radical, etc., or various reactive groups that can be condensation-polymerized can be used.
  • the ultraviolet- thermosetting radical may include a reactive group such as a vinyl radical, an acrylic radical, a methacrylic radical, a vinylidene radical, an aryl radical, etc. among the reactive groups, which can be cross-linked by ultraviolet ray.
  • an initiator and an additive such as a leveling agent, etc., if needed, can be used.
  • a plastic film such as PET (polyethyleneterephthalate) , PVA (polyvinyl alcohol) , TAC (tri-acetyl-cellulose) , etc.
  • PET polyethyleneterephthalate
  • PVA polyvinyl alcohol
  • TAC tri-acetyl-cellulose
  • a method of guiding the horizontal orientation may include a method of forming a horizontal orientation film, a method of applying an electric field, a method of applying shear force, etc.
  • the method of using the horizontal orientation film is used in order to guide the orientation.
  • an orientation film is coated on a substrate material and a cholesteric liquid crystal material is then coated on the orientation film to guide an orientation.
  • the horizontal orientation film may employ polyimide, polyvinyl alcohol, and their derivatives that are typically used in this field.
  • a method of laminating cholestric liquid crystal films having different selective light-reflection central wavelengths is used. Firstly, a horizontal orientation layer is coated on a plastic film in the roll coating method. A solution in which a cholestric liquid crystal material is dissolved is coated on the coated orientation film in the roll coating method. The liquid crystal material is oriented while drying a solvent through a dryer and then irradiated with UV. An orientation layer is coated on the cholestric liquid crystal film in the roll coating method.
  • Cholestric liquid crystal solutions having different selective reflection wavelength regions are coated in the roll coating, dried, and irradiated with UV to form films.
  • the orientation film layers and the cholesteric liquid crystal layers are alternately laminated to form the broadband cholestric liquid crystal film that totally reflects the visible ray region.
  • the 1/4 ⁇ phase film is formed by using PVA, PC, m-COC etc.
  • a phase film having a retardation value of 115 to 125 nm is used.
  • the reflective polarizing film formed thus is inserted between a backlight unit and a liquid crystal panel of an LCD.
  • the optical efficiency can be improved by removing the interface between the films by using an adhesive layer. It is found that the optical efficiency of a case where the air layer is removed by laminating the adhesive layer is 5% higher than that of a case where the air layer exists between the films.
  • the reflective polarizing film fabricated according to the present invention is integrally formed with the conventional absorption-type polarizing plate or a diffusion plate in such a manner that an adhesive layer is interposed between the reflective polarizing film and the absorption-type polarizing plate or the diffusion plate, the optical efficiency such as brightness, etc. can be improved by 10% or greater.
  • a cholesteric liquid crystal film was fabricated.
  • a thermosetting cholestric liquid crystal material (bifunctional acrylate based LC242 and LC756 available from BASF Corporation) was dissolved in a solvent in which methylethylketone (MEK) and toluene are mixed at a ratio of 6:4 to prepare for a solution having a concentration of 50 wt%.
  • MEK methylethylketone
  • the solution was prepared for to have selective reflection central wavelengths of 430, 480, 520, 580, 650 and 720 nm by controlling the ratio of mixing of the nematic material (LC242) and the chiral material (LC756) .
  • a photoinitiator (IG184 available from Ciba-Geigy Corporation) of 5 wt% and a leveling additive (BYK361 available from BYK Corporation) of 0.2 wt% were added to the solution.
  • IG184 available from Ciba-Geigy Corporation
  • BYK361 available from BYK Corporation
  • a horizontal orientation film was thinly coated on the 430- nm cholesteric liquid crystal film in the roll coating method and then dried. At this time, the drying process was performed at a temperature of 85 ° C. Next, the cholesteric liquid crystal solution formed to have a selective wavelength of 480 nm was thinly coated, dried, and irradiated with UV in the same manner to form a film.
  • the cholesteric liquid crystal layers having the central wavelengths of selective reflection of 430, 480, 520, 580, 650 and 720 nm were laminated in order from shorter wavelength to longer wavelength by repeatedly performing the above laminated coating process.
  • the thickness of each of the liquid crystal layers formed thus ranged from 3.5 to 4.5 microns and the total thickness of the film was 25 microns.
  • a 1/4 ⁇ retardation film (having the central wavelength of 115 nm) in which a pressure sensitive adhesive (PSA) is coated on the shorter wavelength face of the liquid crystal film was compressed at a room temperature to form the final reflective polarizing plate.
  • PSA pressure sensitive adhesive
  • the absorption-type polarizing film was based on an NPF grade of Nitto Denko Corporation.
  • a cholesteric liquid crystal film was fabricated.
  • a curable cholesteric liquid crystal material (bifunctional acrylate based LC242 and LC756 available from BASF Corporation) was dissolved in a solvent in which methylethylketone (MEK) and toluene are mixed at a ratio of 6:4 to prepare for a solution having a concentration of 50 wt%.
  • MEK methylethylketone
  • the solution was formed to have selective reflection central wavelengths of 435, 485, 520, 570, 620, 670, and 730nm by controlling the ratio of mixing of the nematic material (LC242) and the chiral material (LC756) .
  • a photoinitiator (IG184 available from Ciba-Geigy Corporation) of 5 wt% and a leveling additive (BYK361 available from BYK Corporation) of 0.2 wt% were added to the solution.
  • the solution having the wavelength of 435 nm was thinly coated on a polyethyleneterephthalate (PET) film on which a polyimide horizontal orientation film (SE7492 available from Nissan Chemical Industries, Ltd.) was coated in the roll coating method. Thereafter, liquid crystal of the solution was oriented while drying the solvent in a dryer and then irradiated with UV to form a film. At this time, the drying process was performed at a temperature of 85 ° C and UV was illuminated by using a 300-W lamp (having the central wavelength of 360 nm) .
  • a horizontal orientation layer was thinly coated on the 435-nm cholesteric liquid crystal film in the roll coating method and then dried. At this time, the drying process was performed at a temperature of 85 ° C. Next, the cholestric liquid crystal solution formed to have a selective wavelength of 485 nm was thinly coated, dried, and irradiated with UV in the same manner to form a film.
  • the cholesteric liquid crystal layers having the central wavelengths of selective reflection of 435, 485, 520, 570, 620, 670, and 730 nm were laminated sequentially in order from shorter wavelength to longer wavelength by repeatedly performing the above laminated coating process.
  • the thickness of each of the liquid crystal layers formed thus ranged from 3.5 to 4.5 microns and the total thickness of the films was 25 microns.
  • a 1/4 ⁇ retardation film (having the central wavelength of 115 nm) in which a pressure sensitive adhesive (PSA) is coated on the short wavelength face of the liquid crystal film was compressed at a room temperature to form the final reflective polarizing plate.
  • PSA pressure sensitive adhesive
  • the present invention since the entire wavelength bands of the visible light region are selectively reflected, it is possible to significantly improve brightness of an LCD compared to that of the conventional absorption-type polarizing plates. Brightness is measured with an actual reflective polarizing plate mounted on an LCD panel. The results of measurement show that brightness in the case where the reflective polarizing plate of the present invention is used is 140, which means that brightness is improved by about 40% assuming that brightness when the reflective polarizing plate of the present invention is not used is 100.

Abstract

The present invention relates to a method of manufacturing a reflective polarizing film for a liquid crystal display device in which cholesteric liquid crystal layers having different selective light-reflecting wavelengths are laminated in the laminated coating method, thus a forming liquid crystal film that covers a visible light region and l/4λ retardation film are attached to the liquid crystal film. In this case, two or more cholestric liquid crystal layers having different selective light-reflecting wavelengths are laminated in order from the shorter wavelength to the longer wavelength in the laminated coating method. Further, during the lamination, orientation layers are laminated between the liquid crystal layers to maximize the selective reflection characteristic of the cholesteric liquid crystal.

Description

BROADBAND REFLECTIVE POLARIZER FOR LIQUID CRYSTAL DISPLAY USING
OVERCOATING METHOD
Technical Field The present invention relates to a method of fabrication of a reflective polarizing film for a liquid crystal display device, in which cholesteric liquid crystal layers having selective light-reflection central wavelengths different from one another are laminated in the laminated coating method, thus forming a liquid crystal film that covers a visible light region, and a quarter wave (1/4 λ) retardation film is attached on the top of the liquid crystal film.
Background Art A liquid crystal display (LCD) device that has been used typically employs a polarizing film using linearly polarized light. The polarizing film is fabricated by adsorbing an iodine or dichroic dye on a polyvinyl alcohol (PVA) film to form a resulting adsorbed film and stretching the resulting adsorbed film in a certain direction.
The polarizing film fabricated thus cannot be used as a practical polarizing film since its mechanical strength is weak with respect to the direction of a transmission axis and a polarizing function is significantly degraded due to shrinkage by heat or moisture.
In order to solve the above problems, a polarizing film having a structure in which an adhesive is adhered between supports such as an acetic acid cellulose film, etc. has been developed.
The polarizing film using the above-described polyvinyl alcohol film produces linearly polarized light by absorbing light that progresses in one direction while passing only light that vibrates in the other direction. Thus, efficiency of the polarizing film does not exceed 50% theoretically, which acts as the most significant factor to reduce the efficiency and brightness of an LCD. If a reflective polarizing film formed by using cholesteric liquid crystal is additionally used, the shortcomings of the conventional polarizing films can be improved greatly. Cholesteric liquid crystals have a selective reflection characteristic in which a twisted direction of a spiral liquid crystal structure and an oriented direction of a circularly polarized light are consistent with each other and only a circularly polarized light of which wavelength is the same as the spiral pitch of the liquid crystal is reflected. If the selective reflection characteristic is employed, it is possible to fabricate a polarizing film that converts non-polarized light of a constant wavelength band into a specific circularly polarized light.
That is, if non-polarized light in which a left circularly polarized light component and a right circularly polarized light component are mixed equally is incident to a cholestric liquid crystal film having a left-wind or right-wind spiral structure, a circularly polarized light of which direction is the same as the spiral direction is reflected and a circularly polarized light of which direction is in the opposite direction to the spiral direction is transmitted. At this time, the transmitted circularly polarized light is converted to a linearly polarized light after passing through a l/4λ retardation film. The circularly polarized light reflected thus has its polarization direction changed and transmitted if it is reflected again from a reflective plate. Thus, the whole circularly polarized light can transmit the liquid crystal film. Accordingly, if the polarizing film formed by using the cholesteric liquid crystal film is employed additionally, brightness can be improved significantly compared to the case in which only a conventional absorption type polarizing film that absorbs 50% light is used because there is no loss of light theoretically. However, a backlight- used in an LCD usually generates light of a visible band (400 to 700 nm) that is a region where colors are displayed. Therefore, the selective reflection wavelength region of the cholestric liquid crystal film has to cover the visible light region. If the selective reflection wavelength region of the cholestric liquid crystal film does not cover the visible light region, light of a certain wavelength which is not selectively reflected get into the polarizing film in a non- polarizing state. Accordingly, there is a problem that the picture quality of the LCD is degraded.
Disclosure of Invention
Accordingly, the present invention is provided in order to solve the above problems, and it is an object of the present invention to provide a method of manufacturing a broadband reflective polarizing film for a liquid crystal display device using a laminated coating method in which brightness is improved remarkably compared to that of the conventional polarizing films.
To achieve the above object, according to the present invention, cholestric liquid crystal layers having selective light-reflecting central wavelengths different from one another are laminated in the laminated coating method to form a liquid crystal film that covers a visible ray. Orientation layers are coated between the liquid crystal layers one by one, thus improving the optical properties of cholestric liquid crystals to the maximum.
Brief Description of Drawings
Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a cross-sectional view showing the structure of a film according to the present invention; and
FIG. 2 is a cross-sectional view showing the structure of a liquid crystal display according to the present invention.
Best Mode for Carrying Out the Invention The present invention will now be described in detail in connection with preferred embodiments with reference to the accompanying drawings. In the present invention, a cholestric liquid crystal film that is formed by dissolving a curable cholesteric liquid crystal material and a photoinitiator in an organic solvent, coating them on a substrate and curing or polymerizing by irradiating the mixed material with UV. The cholesteric liquid crystal material is composed of a curable nematic liquid crystal material and a curable chiral material. It is possible to control a selective light-reflecting central wavelength depending on the composition of the two materials. The curable nematic liquid crystal material can be used if they are liquid crystal materials containing a mesogenic radical group representing a nematic liquid crystal. If a chiral material is a material having typical chiral carbons, it can be used. Thus, they are not limited to specific materials. In the present invention, any material which contains a thermal or ultraviolet reactive group in its molecular structure is acceptable for a curable material.
For example, in the case of curing, a combination of monomers having an alkenyl radical such as a vinyl radical, an acrylic radical, a methacrylic radical, a vinylidene radical, an aryl radical, etc., or various reactive groups that can be condensation-polymerized can be used. The ultraviolet- thermosetting radical may include a reactive group such as a vinyl radical, an acrylic radical, a methacrylic radical, a vinylidene radical, an aryl radical, etc. among the reactive groups, which can be cross-linked by ultraviolet ray. For curing or thermosetting, an initiator and an additive such as a leveling agent, etc., if needed, can be used.
When the liquid crystal material is coated, a plastic film such as PET (polyethyleneterephthalate) , PVA (polyvinyl alcohol) , TAC (tri-acetyl-cellulose) , etc., can be used as a substrate. When coating the cholesteric liquid crystal material, a selective reflection characteristic can be assigned to the cholesteric liquid crystal material only when a horizontal orientation is guided. A method of guiding the horizontal orientation may include a method of forming a horizontal orientation film, a method of applying an electric field, a method of applying shear force, etc.
In the present invention, the method of using the horizontal orientation film is used in order to guide the orientation. In this method, an orientation film is coated on a substrate material and a cholesteric liquid crystal material is then coated on the orientation film to guide an orientation.
The horizontal orientation film may employ polyimide, polyvinyl alcohol, and their derivatives that are typically used in this field. In order to manufacture a broadband cholesteric liquid crystal film that totally selectively reflects a visible ray region, a method of laminating cholestric liquid crystal films having different selective light-reflection central wavelengths is used. Firstly, a horizontal orientation layer is coated on a plastic film in the roll coating method. A solution in which a cholestric liquid crystal material is dissolved is coated on the coated orientation film in the roll coating method. The liquid crystal material is oriented while drying a solvent through a dryer and then irradiated with UV. An orientation layer is coated on the cholestric liquid crystal film in the roll coating method. Cholestric liquid crystal solutions having different selective reflection wavelength regions are coated in the roll coating, dried, and irradiated with UV to form films. By employing the above method, the orientation film layers and the cholesteric liquid crystal layers are alternately laminated to form the broadband cholestric liquid crystal film that totally reflects the visible ray region.
Light that passes through the cholesteric liquid crystal film is in a circularly polarized light state. Thus, the light has to be converted to a linearly polarized light so that it can be used in an LCD. This is solved by attaching a 1/4 λ phase film (a quarter wave retardation film) .
The 1/4 λ phase film is formed by using PVA, PC, m-COC etc. In this case, a phase film having a retardation value of 115 to 125 nm is used. The reflective polarizing film formed thus is inserted between a backlight unit and a liquid crystal panel of an LCD. At this time, the optical efficiency can be improved by removing the interface between the films by using an adhesive layer. It is found that the optical efficiency of a case where the air layer is removed by laminating the adhesive layer is 5% higher than that of a case where the air layer exists between the films. Therefore, in the case where the reflective polarizing film fabricated according to the present invention is integrally formed with the conventional absorption-type polarizing plate or a diffusion plate in such a manner that an adhesive layer is interposed between the reflective polarizing film and the absorption-type polarizing plate or the diffusion plate, the optical efficiency such as brightness, etc. can be improved by 10% or greater.
The present invention will now be described in more detail in connection with the following preferred embodiments. It is to be noted that the following preferred embodiments are only illustrative and the present invention is not limited to these preferred embodiments.
Preferred Embodiment 1 A cholesteric liquid crystal film was fabricated. A thermosetting cholestric liquid crystal material (bifunctional acrylate based LC242 and LC756 available from BASF Corporation) was dissolved in a solvent in which methylethylketone (MEK) and toluene are mixed at a ratio of 6:4 to prepare for a solution having a concentration of 50 wt%. The solution was prepared for to have selective reflection central wavelengths of 430, 480, 520, 580, 650 and 720 nm by controlling the ratio of mixing of the nematic material (LC242) and the chiral material (LC756) . A photoinitiator (IG184 available from Ciba-Geigy Corporation) of 5 wt% and a leveling additive (BYK361 available from BYK Corporation) of 0.2 wt% were added to the solution. Among the solutions formed in the above, firstly, the solution having a wavelength of 430 nm was thinly coated on a polyethyleneterephthalate (PET) substrate film on which a polyimide horizontal orientation layer (SE7492 available from
Nissan Chemical Industries, Ltd.) is coated in the roll coating method. Thereafter, liquid crystal of the solution was oriented while drying the solvent in a dryer and irradiating with UV to form a film. At this time, the drying process was performed at a temperature of 85°C and UV was illuminated by using a 300-W lamp
(having the central wavelength of 360 nm) . A horizontal orientation film was thinly coated on the 430- nm cholesteric liquid crystal film in the roll coating method and then dried. At this time, the drying process was performed at a temperature of 85°C. Next, the cholesteric liquid crystal solution formed to have a selective wavelength of 480 nm was thinly coated, dried, and irradiated with UV in the same manner to form a film.
The cholesteric liquid crystal layers having the central wavelengths of selective reflection of 430, 480, 520, 580, 650 and 720 nm were laminated in order from shorter wavelength to longer wavelength by repeatedly performing the above laminated coating process. The thickness of each of the liquid crystal layers formed thus ranged from 3.5 to 4.5 microns and the total thickness of the film was 25 microns.
A 1/4 λ retardation film (having the central wavelength of 115 nm) in which a pressure sensitive adhesive (PSA) is coated on the shorter wavelength face of the liquid crystal film was compressed at a room temperature to form the final reflective polarizing plate.
It was found that brightness of the reflective polarizing film formed thus was improved by more than 40% compared to the case where an absorption-type polarizing film was used. (In this case, the absorption-type polarizing film was based on an NPF grade of Nitto Denko Corporation.)
Preferred Embodiment 2
A cholesteric liquid crystal film was fabricated. A curable cholesteric liquid crystal material (bifunctional acrylate based LC242 and LC756 available from BASF Corporation) was dissolved in a solvent in which methylethylketone (MEK) and toluene are mixed at a ratio of 6:4 to prepare for a solution having a concentration of 50 wt%. At this time, the solution was formed to have selective reflection central wavelengths of 435, 485, 520, 570, 620, 670, and 730nm by controlling the ratio of mixing of the nematic material (LC242) and the chiral material (LC756) . A photoinitiator (IG184 available from Ciba-Geigy Corporation) of 5 wt% and a leveling additive (BYK361 available from BYK Corporation) of 0.2 wt% were added to the solution. Among the solutions formed in the above, the solution having the wavelength of 435 nm was thinly coated on a polyethyleneterephthalate (PET) film on which a polyimide horizontal orientation film (SE7492 available from Nissan Chemical Industries, Ltd.) was coated in the roll coating method. Thereafter, liquid crystal of the solution was oriented while drying the solvent in a dryer and then irradiated with UV to form a film. At this time, the drying process was performed at a temperature of 85°C and UV was illuminated by using a 300-W lamp (having the central wavelength of 360 nm) .
A horizontal orientation layer was thinly coated on the 435-nm cholesteric liquid crystal film in the roll coating method and then dried. At this time, the drying process was performed at a temperature of 85°C. Next, the cholestric liquid crystal solution formed to have a selective wavelength of 485 nm was thinly coated, dried, and irradiated with UV in the same manner to form a film.
The cholesteric liquid crystal layers having the central wavelengths of selective reflection of 435, 485, 520, 570, 620, 670, and 730 nm were laminated sequentially in order from shorter wavelength to longer wavelength by repeatedly performing the above laminated coating process. The thickness of each of the liquid crystal layers formed thus ranged from 3.5 to 4.5 microns and the total thickness of the films was 25 microns.
A 1/4 λ retardation film (having the central wavelength of 115 nm) in which a pressure sensitive adhesive (PSA) is coated on the short wavelength face of the liquid crystal film was compressed at a room temperature to form the final reflective polarizing plate.
It was found that brightness of the reflective polarizing film formed thus was improved by more than 36% compared to the case where an absorption-type polarizing film was used. Industrial Applicability
As described in the above, according to the present invention, since the entire wavelength bands of the visible light region are selectively reflected, it is possible to significantly improve brightness of an LCD compared to that of the conventional absorption-type polarizing plates. Brightness is measured with an actual reflective polarizing plate mounted on an LCD panel. The results of measurement show that brightness in the case where the reflective polarizing plate of the present invention is used is 140, which means that brightness is improved by about 40% assuming that brightness when the reflective polarizing plate of the present invention is not used is 100.

Claims

What Is Claimed Is:
1. A method of manufacturing a broadband reflective polarizing plate using a laminated coating technique, comprising the steps of:
(a) coating a substrate film on which a first orientation layer is coated with a cholesteric liquid crystal solution;
(b) irradiating a cholesteric liquid crystal coating layer formed in (a) with UV to form a liquid crystal film; (c) coating said liquid crystal layer formed in (b) with a second orientation layer;
(d) coating said second orientation layer with said cholesteric liquid crystal solution having different selective light-reflecting central wavelengths on to form a cholesteric liquid crystal coating layer; and
(e) irradiating said cholesteric liquid crystal coating layer with UV to form a cholesteric liquid crystal film, wherein two or more cholesteric liquid crystal layers having different selective light-reflecting central wavelengths, which are manufactured by repeatedly performing the above steps
(c) to (e) once or more times, are sequentially laminated in order from shorter wavelength to longer wavelength in the laminated coating method, thus forming a broadband reflective polarizing plate covering the range of visible light as a selective reflection wavelength region.
2. The method of claim 1, wherein said cholesteric liquid crystal film is formed by mixing a curable nematic liquid crystal material and a curable chiral liquid crystal material and then irradiating the mixture with UV.
3. The method of claim 1, wherein said cholesteric liquid crystal film is formed in such a manner that the selective light-reflecting central wavelengths of said cholesteric liquid crystal layers are adjusted to be different by controlling the ratio of mixing of a nematic liquid crystal material and a chiral liquid crystal material and then irradiating the mixture with UV.
4. The method as claimed in claim 1, wherein said first and second orientation layers are films that can horizontally orientate a nematic liquid crystal.
5. A broadband reflective polarizing plate covering the range of visible light as a selective light-reflecting central wavelength, which is fabricated in the method according to any one of claims 1 to 4, wherein the number of said first and second orientation layers and cholesteric liquid crystal layers is two or more, the cholesteric liquid crystal layers have different selective light-reflecting central wavelengths, and the cholestric liquid crystal coating layers are laminated sequentially in order from shorter wavelength to longer wavelength in the laminated coating method.
6. A method of manufacturing a broadband reflective polarizing plate, comprising the steps of:
(a) coating a substrate film on which a first orientation layer is coated with a cholesteric liquid crystal solution; (b) irradiating a cholesteric liquid crystal layer formed in (a) with light to form a liquid crystal film;
(c) coating said liquid crystal layer formed in (b) with a second orientation layer;
(d) coating said second orientation layer with said cholesteric liquid crystal solution having different selective light-reflecting central wavelengths on the orientation layer to form a cholesteric liquid crystal film; and
(e) irradiating said cholesteric liquid crystal coating layer with light to form a cholesteric liquid crystal film, wherein two or more cholesteric liquid crystal layers having different selective light-reflecting central wavelengths, which are manufactured by repeatedly performing the above steps
(c) to (e) once or more times, are sequentially laminated in order from shorter wavelength to longer wavelength in the laminated coating method, and a retardation film is laminated on the broadband reflective polarizing plate having a visible light region as a selective reflection wavelength region.
7. The method of claim 6, wherein said cholesteric liquid crystal film is formed by mixing a curable nematic liquid crystal material and a curable chiral liquid crystal material • and then irradiating the mixture with UV.
8. The method of claimed claim 6, wherein said first and second orientation layers are films that can horizontally orientate a nematic liquid crystal.
9. The method of claim 6, wherein said phase-difference film is attached to the side of said cholesteric liquid crystal film having the shortest wavelength of said broadband reflective polarizing plate.
10. The broadband reflective polarizing plate manufactured by laminating reflective polarizing plate comprised of two or more laminated structures comprised of said first and second orientation layers and cholesteric liquid crystal layers manufactured according to any of claims 6 through 9, and a retardation film.
11. A liquid crystal display, wherein two or more cholesteric liquid crystal layers having different selective light-reflecting central wavelengths are laminated sequentially in order from shorter wavelength to longer wavelength in the laminated coating method to form a broadband reflective polarizing plate covering the range of visible light as a selective reflection wavelength region, and then retardation film is laminated on the broadband reflective polarizing plate to form a reflective polarizing plate which in turn is disposed between a backlight and a liquid crystal cell unit, said two or more cholesteric liquid crystal layers being formed by repeatedly performing the steps of coating an orientation layer on a base film and drying a first orientation layer, coating a cholesteric liquid crystal solution on the base film in which said first orientation layer is coated and then irradiating said cholesteric liquid crystal solution layer with light to form a liquid crystal film.
12. The liquid crystal display of claim 11, wherein said cholesteric liquid crystal film is formed by mixing a curable nematic liquid crystal material and a curable chiral liquid crystal material and then irradiating the mixture with UV.
13. The liquid crystal display of claim 11, wherein said first and second orientation layer is an orientation film that can horizontally orientate a nematic liquid crystal.
14. The broadband reflective polarizing plate manufactured by using the laminated coating method, wherein the broadband reflective polarizing plate in which the number of laminated structures of said first and second orientation layers and the cholesteric liquid crystal layer is two or more, is integrally formed with an absorption type polarizing plate or a diffusion plate being laminated in such a manner that an adhesive layer is interposed between the absorption type polarizing plate or the diffusion plate and the reflective polarizing plate being fabricated in the method according to any one of claims 6 to 9.
PCT/KR2004/003013 2004-08-02 2004-11-19 Broadband reflective polarizer for liquid crystal display using overcoating method WO2006014041A1 (en)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008077075A (en) * 2006-08-23 2008-04-03 Jds Uniphase Corp Cartesian polarizer utilizing photo-aligned liquid crystal
CN101311796B (en) * 2007-05-25 2010-06-23 台湾薄膜电晶体液晶显示器产业协会 Reflecting type optical film preparation method and reflecting type polarizing film and method of manufacture
WO2016071908A1 (en) * 2014-11-06 2016-05-12 Gauzy Ltd. Bistable liquid crystal dispersion devices comprising metal-organic mesogens and applications thereof
US10851302B2 (en) 2014-10-20 2020-12-01 Gauzy Ltd. Metal organic liquid crystal dyes
US11493797B2 (en) 2014-10-20 2022-11-08 Gauzy Ltd. Dynamic signage, glazed and patterned PDLC devices and methods for creating thereof

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006095977A1 (en) * 2005-03-09 2006-09-14 Samsung Fine Chemicals Co., Ltd. Broadband reflection type brightness enhancement polarizer and liquid crystal display having the same
KR100867011B1 (en) 2006-02-27 2008-11-10 주식회사 엘지화학 Very thin achromatic quater wave film laminate for transflective lcd and method for producing the same
KR101400385B1 (en) * 2007-12-04 2014-05-26 엘지디스플레이 주식회사 Composition of retardation compensation film and method of fabricating retardation compensation film for liquid crystal display device using the same
EP2442160A4 (en) * 2009-06-11 2012-11-07 Fujifilm Corp Process for production of light reflection film
CN102749669A (en) * 2012-06-20 2012-10-24 京东方科技集团股份有限公司 Reflecting polaroid, method for producing same and liquid crystal display device
KR101952910B1 (en) * 2012-12-13 2019-02-27 엘지디스플레이 주식회사 Light filter and display device including the same
WO2015077724A1 (en) 2013-11-25 2015-05-28 3M Innovative Properties Company Optical film stack including retardation layer
US9693839B2 (en) 2014-07-17 2017-07-04 Align Technology, Inc. Probe head and apparatus for intraoral confocal imaging using polarization-retarding coatings

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1144890A (en) * 1997-07-28 1999-02-16 Toshiba Corp Liquid crystal display device and production of color filter substrate
JP2002169021A (en) * 2000-12-04 2002-06-14 Toshiba Corp Polarizing reflection element, liquid crystal display element having the same and method for manufacturing polarizing reflection element
KR20040005420A (en) * 2002-07-10 2004-01-16 엘지.필립스 엘시디 주식회사 Liquid crystal display device with a cholesteric liquid crystal polarizer
JP2004029743A (en) * 2002-04-23 2004-01-29 Nitto Denko Corp Polarizing element, polarizing light source and picture display device using them

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5050966A (en) 1988-07-06 1991-09-24 Kaiser Aerospace & Electronics Corporation Optical combiner collimating apparatus
US5235443A (en) 1989-07-10 1993-08-10 Hoffmann-La Roche Inc. Polarizer device
DE69731806T2 (en) 1996-04-22 2005-04-21 Nitto Denko Corp OPTICAL ELEMENT WITH CIRCULAR DICHROISM, DEVICE THEREFOR AND LIQUID CRYSTAL POLYMER
US6061108A (en) 1997-01-24 2000-05-09 Sharp Kabushiki Kaisha Broadband cholesteric polarizer and an optical device employing the same
US6248259B1 (en) 1997-04-28 2001-06-19 Nitto Denko Corporation Optically active monomer, liquid crystal polymer, and optical element
JP3552084B2 (en) 1997-05-29 2004-08-11 日東電工株式会社 Circularly polarized light separating plate, manufacturing method thereof, optical element, polarized light source device and liquid crystal display device
JP3580125B2 (en) 1998-03-05 2004-10-20 日東電工株式会社 Optical element, lighting device and liquid crystal display device
JP3580124B2 (en) 1998-03-05 2004-10-20 日東電工株式会社 Optical element, lighting device and liquid crystal display device
KR100675997B1 (en) 1999-07-02 2007-01-29 메르크 파텐트 게엠베하 Process of preparing a multilayer cholesteric film
KR100675996B1 (en) 1999-07-02 2007-01-29 메르크 파텐트 게엠베하 Process of preparing a multilayer cholesteric film
JP2002139624A (en) * 2000-11-06 2002-05-17 Nitto Denko Corp Optical element, illumination device and liquid crystal display device

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1144890A (en) * 1997-07-28 1999-02-16 Toshiba Corp Liquid crystal display device and production of color filter substrate
JP2002169021A (en) * 2000-12-04 2002-06-14 Toshiba Corp Polarizing reflection element, liquid crystal display element having the same and method for manufacturing polarizing reflection element
JP2004029743A (en) * 2002-04-23 2004-01-29 Nitto Denko Corp Polarizing element, polarizing light source and picture display device using them
KR20040005420A (en) * 2002-07-10 2004-01-16 엘지.필립스 엘시디 주식회사 Liquid crystal display device with a cholesteric liquid crystal polarizer

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008077075A (en) * 2006-08-23 2008-04-03 Jds Uniphase Corp Cartesian polarizer utilizing photo-aligned liquid crystal
US8072683B2 (en) * 2006-08-23 2011-12-06 Jds Uniphase Corporation Cartesian polarizers utilizing photo-aligned liquid crystals
TWI406018B (en) * 2006-08-23 2013-08-21 Jds Uniphase Corp Cartesian polarizers utilizing photo-aligned liquid crystals
CN101311796B (en) * 2007-05-25 2010-06-23 台湾薄膜电晶体液晶显示器产业协会 Reflecting type optical film preparation method and reflecting type polarizing film and method of manufacture
US10851302B2 (en) 2014-10-20 2020-12-01 Gauzy Ltd. Metal organic liquid crystal dyes
US11493797B2 (en) 2014-10-20 2022-11-08 Gauzy Ltd. Dynamic signage, glazed and patterned PDLC devices and methods for creating thereof
WO2016071908A1 (en) * 2014-11-06 2016-05-12 Gauzy Ltd. Bistable liquid crystal dispersion devices comprising metal-organic mesogens and applications thereof
CN107429164A (en) * 2014-11-06 2017-12-01 哥兹有限公司 Bistable liquid crystal comprising metallomesogen primitive disperses body device and its application

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