Liquid crystal display device having compensator with particular retardation in the inclined direction
First Claim
1. A liquid crystal display device comprising:
- a pair of polarizers,a liquid crystal display cell disposed between the pair of polarizers, and interposing a liquid crystal layer of liquid crystal molecules twisted by 180°
to 270°
between a pair of substrate members,a first optical compensation plate disposed between at least one polarizer of the pair of polarizers and the liquid crystal display cell, the first optical compensation plate having a refractive index anisotropy in a plane, and having a refractive index in the thickness direction nearly equal to the refractive index of the minimum value within the plane, anda second optical compensation plate disposed between the first optical compensation plate and the one polarizer, the second optical compensation having no refractive index anisotropy in the plane, the second optical compensation plate having a refractive index in the thickness direction greater than the refractive index in the plane, and expressing a positive phase difference depending on an inclination from the normal direction,wherein the retardation value of the second optical compensation plate in the direction inclined by 45°
from the normal direction is selected to be in a range of 40 nm to 75 nm.
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Accused Products
Abstract
It is an object of the invention to provide a liquid crystal display device capable of obtaining a wide viewing angle without coloration caused by a viewing angle. A liquid crystal display cell is disposed between a pair of polarizers, and between the liquid crystal display cell and the pair of polarizers, first optical compensation plates are disposed at the side of the liquid crystal display cell, and second optical compensation plates are disposed at the side of the polarizer. The first optical compensation plates have a refractive index anisotropy in the plane, and the refractive index thereof in the thickness direction is nearly equal to the refractive index of a minimum value in the plane, whereas the second optical compensation plates have no refractive index anisotropy in the plane, the refractive index in the thickness direction is greater than the refractive index in the plane, and a positive phase difference is expressed by inclination from the normal direction. By the optical compensation plates, the coloration of the display in the display plane of the liquid crystal display device and in the viewing angle direction inclined in a direction parallel to the display plane from the normal direction of the display plane can be compensated, so that a wide viewing angle of a high contrast is obtained.
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Citations
7 Claims
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1. A liquid crystal display device comprising:
-
a pair of polarizers, a liquid crystal display cell disposed between the pair of polarizers, and interposing a liquid crystal layer of liquid crystal molecules twisted by 180°
to 270°
between a pair of substrate members,a first optical compensation plate disposed between at least one polarizer of the pair of polarizers and the liquid crystal display cell, the first optical compensation plate having a refractive index anisotropy in a plane, and having a refractive index in the thickness direction nearly equal to the refractive index of the minimum value within the plane, and a second optical compensation plate disposed between the first optical compensation plate and the one polarizer, the second optical compensation having no refractive index anisotropy in the plane, the second optical compensation plate having a refractive index in the thickness direction greater than the refractive index in the plane, and expressing a positive phase difference depending on an inclination from the normal direction, wherein the retardation value of the second optical compensation plate in the direction inclined by 45°
from the normal direction is selected to be in a range of 40 nm to 75 nm. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification