Vertically aligned LCD using a bi-axial retardation compensation film
First Claim
1. A vertically aligned LCD using a multi-domain mode or a chiral additive, provided with a bi-axial retardation compensation film, in which a vertically aligned panel is formed by injecting liquid crystal having a negative dielectric anisotropy or a positive dielectric anisotropy into a gap between upper and lower glass substrates, and upper and lower polarizing plates are arranged above the upper and lower surfaces of the vertically aligned panel so that optical absorption axes of the polarizing plates are perpendicular to each other with the vertically aligned panel as the central figure, and a cell gap in the range of 3 μ
- m to 8 μ
m is maintained,a liquid crystal cell is prepared by arranging the bi-axial retardation compensation film between the vertically aligned panel and the upper or lower polarizing plate in which the relationship of the in-plane refraction index nx and ny) and the thickness refraction index nz of the bi-axial retardation compensation film is nx>
ny>
nz; and
an optical axis of the bi-axial retardation compensation film is arranged to be perpendicular to an absorption axis of an adjacent polarizing plate, and the bi-axial retardation compensation film has a reversed wavelength dispersion in which a in-plane retardation is increased in proportion to the increase of a wavelength in the range of visible rays, and has a normal wavelength dispersion in which an absolute value of the thickness retardation is decreased in proportion to the increase of a wavelength in the range of visible rays, and has an in-plane retardation (Rin) in the range of 30˜
150 nm at a wavelength of 550 nm,wherein a wavelength dispersion (Rin,400/Rin,550) is in the range of 0.4˜
0.9 at wavelengths of 400 nm and 550 nm, and a wavelength dispersion (Rin,700/Rin,550) is in the range of 1.1˜
1.8 at wavelengths of 700 nm and 550 nm, wherein Rin,400, Rin,550 and Rin,700 are in-plane retardations at wavelengths of 400 nm, 550 nm and 700 nm,wherein a wavelength dispersion (Rth,400/Rth,550) is in the range of 1.05˜
1.4 at wavelengths of 400 nm and 550 nm, and a wavelength dispersion (Rth,700/Rth,550) is in the range of 0.5˜
0.95 at wavelengths of 700 nm and 550 nm, wherein Rth,400, Rth,550 and Rth,700 are thickness retardations at wavelengths of 400 nm, 550 nm and 700 nm,wherein a liquid crystalline layer of the VA-panel has a retardation in the range of 80 nm to 400 nm at a wavelength of 550 nm.
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Accused Products
Abstract
The present invention relates to a vertically aligned LCD (VA-LCD) employing a bi-axial retardation compensation film, in which an in-plain refractive index (nx, ny) and a thickness refractive index (nz) of the film is nx>ny>nz. The film has a reversed wavelength dispersion in which retardation is increased in proportion to the increase of a wavelength in the range of visible rays and has a normal wavelength dispersion in which an absolute value of the thickness retardation is decreased in proportion to the increase of a wavelength in the range of visible rays. The VA-LCD cell having a retardation compensation characteristic is comprised by arranging a bi-axial retardation compensation film between the vertically aligned panel and a upper and lower polarizing plate. The VA-LCD of the present invention improves contrast characteristics on a front surface and at a tilt angle and minimizes coloring in a black state according to the tilt angle.
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Citations
8 Claims
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1. A vertically aligned LCD using a multi-domain mode or a chiral additive, provided with a bi-axial retardation compensation film, in which a vertically aligned panel is formed by injecting liquid crystal having a negative dielectric anisotropy or a positive dielectric anisotropy into a gap between upper and lower glass substrates, and upper and lower polarizing plates are arranged above the upper and lower surfaces of the vertically aligned panel so that optical absorption axes of the polarizing plates are perpendicular to each other with the vertically aligned panel as the central figure, and a cell gap in the range of 3 μ
- m to 8 μ
m is maintained,a liquid crystal cell is prepared by arranging the bi-axial retardation compensation film between the vertically aligned panel and the upper or lower polarizing plate in which the relationship of the in-plane refraction index nx and ny) and the thickness refraction index nz of the bi-axial retardation compensation film is nx>
ny>
nz; andan optical axis of the bi-axial retardation compensation film is arranged to be perpendicular to an absorption axis of an adjacent polarizing plate, and the bi-axial retardation compensation film has a reversed wavelength dispersion in which a in-plane retardation is increased in proportion to the increase of a wavelength in the range of visible rays, and has a normal wavelength dispersion in which an absolute value of the thickness retardation is decreased in proportion to the increase of a wavelength in the range of visible rays, and has an in-plane retardation (Rin) in the range of 30˜
150 nm at a wavelength of 550 nm,wherein a wavelength dispersion (Rin,400/Rin,550) is in the range of 0.4˜
0.9 at wavelengths of 400 nm and 550 nm, and a wavelength dispersion (Rin,700/Rin,550) is in the range of 1.1˜
1.8 at wavelengths of 700 nm and 550 nm, wherein Rin,400, Rin,550 and Rin,700 are in-plane retardations at wavelengths of 400 nm, 550 nm and 700 nm,wherein a wavelength dispersion (Rth,400/Rth,550) is in the range of 1.05˜
1.4 at wavelengths of 400 nm and 550 nm, and a wavelength dispersion (Rth,700/Rth,550) is in the range of 0.5˜
0.95 at wavelengths of 700 nm and 550 nm, wherein Rth,400, Rth,550 and Rth,700 are thickness retardations at wavelengths of 400 nm, 550 nm and 700 nm,wherein a liquid crystalline layer of the VA-panel has a retardation in the range of 80 nm to 400 nm at a wavelength of 550 nm. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- m to 8 μ
Specification