Nitto-denko Corporation

Masayuki Kawai

Shuuji Yano

Takashi Yamaoka

Ryouji Kinoshita

Junichi Adachi

Kanako Wasai

Nao Murakami

Seiji Umemoto

Hiroyuki Yoshimi

Masahiro Hata

An elliptically polarizing plate including: a polarizer; and an optical film that includes a laminate of: a retardation film A that includes a cyclic polyolefin resin-containing thermoplastic polymer and has uniaxially-aligned positive refractive-index anisotropy characterized by nx&#x3e;ny&#x2248;nz; and a retardation film B that is fixed to homeotropic alignment and has positive refractive-index anisotropy characterized by nz1&#x3e;nx1&#x2248;ny1, wherein the optical film is laminated on one side of the polarizer in such a manner that a slow axis of the retardation film A is perpendicular to an absorption axis of the polarizer. The elliptically polarizing plate can suppress a reduction in contrast at wide viewing angles when applied to in-plane switching mode active matrix liquid crystal displays, and can be highly effective for improvements against color shift.

Elliptically polarizing plate and image display

An IPS mode liquid crystal display comprising a liquid crystal cell, an optical film (F) provided on a cell substrate on one side of the liquid crystal cell and comprises a polarizing plate comprising a transparent protective film having an in-plane retardation Re 10 nm or less and a thickness direction retardation Rth in the range of from 30 to 100 nm, a retardation film having an Nz value in the range of from 0.3 to 0.7 and an in-plane retardation Rein the range of from 200 to 300 nm, and an optical film (F) provided on a cell substrate on the other side of the liquid crystal cell and comprises the polarizing plate and a retardation film having an Nz value in the range of from 0.9 to 1.2 and an in-plane retardation Rein the range of from 150 to 280 nm, and the absorption axes of the polarizing plates of the optical film (F) and the optical film (F) are perpendicular to each other, and both films are disposed so that the retardation film sides face the liquid crystal cell. The IPS mode liquid crystal display has a high contrast ratio across a wide range, and capable of realizing a better view.

IPS mode liquid crystal display

An optical film() of the invention comprises a polarizing plate() and plural retardation films() so that an absorption axis of the polarizing plate() is perpendicular or parallel to slow axes of the plural retardation films() and the slow axes of the plural retardation films() are parallel to one another. An Nz value expressed by Nz=(nx&#x2212;nz)/(nx&#x2212;ny) is in the range of from 0.15 to 0.85 and an in-plane retardation Reexpressed by Re=(nx&#x2212;ny)&#xd7;dis in the range of from 200 to 350 nm, where in each of the plural retardation films, a direction along with the refractive index in the film plane is maximum is defined as the X-axis, a direction perpendicular to the X-axis as the Y-axis, the thickness direction of the film as the Z-axis, and where refractive indices in each axial direction are defined as nx, ny, and nz, respectively, and the thickness of the film as d(nm). The optical film may realize an easily viewable display with high contrast ratio in a wide range.

Optical film and image display

An optical film () of the invention comprises a polarizing Plate (), in which a transparent protective film () is laminated on both sides of a polarizer (), and plural retardation films () so that an absorption axis of the polarizing plate () is perpendicular or parallel to slow axes of the plural retardation films () and the slow axes of the plural retardation films () are parallel to one another. An Nz value expressed by Nz=(nx&#x2212;nz)/(nx&#x2212;ny) is in the range of from 0.15 to 0.85 and an in-plane retardation Reexpressed by Re=(nx&#x2212;ny)&#xd7;dis in the range of from 200 to 350 nm, where in each of the plural retardation films, a direction along with the refractive index in the film plane is maximum is defined as the X-axis, a direction perpendicular to the X-axis as the Y-axis, the thickness direction of the film as the Z-axis, and where refractive indices in each axial direction are defined as nx, ny, and nz, respectively, and the thickness of the film as d(nm). The optical film may realize an easily viewable display with high contrast ratio in a wide range and may provide a retardation value stabilized under conditions of high temperature or high humidity.

Optical film and image viewing display

A liquid crystal display of the invention comprises an in-plane switching liquid crystal panel containing a liquid crystal layer whose alignment orientation changes according to an electric field in parallel with a surface of a substrate; a first polarizing plate and a second polarizing plate disposed sandwiching the liquid crystal panel therebetween; a first optical film inserted between the first polarizing plate and the liquid crystal panel; and a second optical film inserted between the second polarizing plate and the liquid crystal panel, wherein the first optical film includes: a retardation film Ahaving a relation of nz&#x3e;nx&#x2267;ny; and a retardation film B having an in-plane retardation (Re) in the range of from 200 to 300 nm, a relation of nx&#x3e;nz&#x3e;ny and satisfying Nz coefficient in the range of 0.3&#x3c;Nz&#x3c;0.7, in which three-dimensional refractive indices are controlled; the second optical film includes a retardation film Ahaving a relation of nz&#x3e;nx&#x2267;ny; and the slow axis of the retardation film B is in parallel with or perpendicular to the absorption axes of the first and second polarizing plates. The liquid crystal display has a high contrast ratio over a wide range.

Liquid crystal display

The present invention provides an optical compensation plate having an optical compensation layer in which occurrence of cracks due to an applied pressure and deformation caused by heat or the like are suppressed. By applying an adhesive that contains a moisture-curing isocyanate compound and has a glass transition temperature of 100&#xb0; C. or less onto at least one surface of the optical compensation layer and curing the adhesive, an anti-cracking layer is formed directly on the surface of the optical compensation layer. The occurrence of cracks and the deformation in the optical compensation layer can be prevented by this anti-cracking layer. The optical compensation layer preferably is a layer having a cholesteric structure, and a constituent material thereof preferably is a non-liquid crystal polymer formed by polymerizing aligned liquid crystal monomers or an aligned liquid crystal polymer.

Optical compensation plate, polarizing plate using the same and image display apparatus using the same

A method for preparing an optical film, which comprises applying and developing an application liquid mixture containing a liquid crystal monomer, a chiral agent and a polymerization initiator on an orientation substrate, subjecting the resultant developed layer to a heat treatment, to orient the monomer to a cholesteric structure, and then subjecting the developed layer to a poltmerization treatment, to polymerize the oriented liquid crystal monomer, thereby forming an optical film exhibiting a selective reflection wave length of 100 to 320 nm. An optical film prepared by the above method is reduced in the coloring due to selective reflection.

Optical film, method for manufacturing the same, and phase difference film and polarizing plate using the same

The present invention provides an optical compensation plate having an optical compensation layer in which cracks occurring due to an applied pressure is suppressed. By applying a curable adhesive agent onto at least one surface of the optical compensation layer and curing the adhesive, an anti-cracking layer is formed directly on the surface of the optical compensation layer. The occurrence of cracks in the optical compensation layer can be prevented by this anti-cracking layer. The optical compensation layer preferably is a layer having a cholesteric structure, and the constituent material thereof is preferably a non-liquid crystal polymer formed by polymerizing aligned liquid crystal monomers or an aligned liquid crystal polymer.

Optical compensation plate and deflecting plate using the same

An optical film obtained by stretching a polymer film comprising a polycarbonate resin and a styrene resin: wherein a photoelastic coefficient is 2.0&#xd7;10to 6.0&#xd7;10m/N, and a three dimensional refractive index is controlled so that an Nz coefficient may satisfy a relationship of Nz&#x2266;0.9 and a front retardation (Re) may satisfy a relationship of Re&#x2267;80 nm, has characteristics of giving wide viewing angle and also outstanding durability.

Optical film, polarizing optical film, and image viewing display

A polarizing plate with an optical compensation layer is provided, which has an excellent peelability and is easy to reattach after mounted on an image display apparatus. A pressure-sensitive adhesive layer satisfying the condition (I) below is formed on both surfaces of an optical compensation layer, and one of the pressure-sensitive adhesive layers is further laminated with a polarizing plate. condition (I): in the case where a pressure-sensitive adhesive layer causing the optical compensation layer and the polarizing plate to adhere to each other is expressed by a pressure-sensitive adhesive layer (A) and the other pressure-sensitive adhesive layer is expressed by a pressure-sensitive adhesive layer (B) and attached to a glass substrate, the pressure-sensitive adhesive layer (A) causing the optical compensation layer and the polarizing plate to adhere to each other has an adhesive strength exceeding 12 N/25 mm, and the pressure-sensitive adhesive layer (B) causing the optical compensation layer and the glass substrate to adhere to each other has an adhesive strength of 1 to 10 N/25 mm.

Growing community of inventors

Ibaraki, Japan

Masayuki Kawai