Vertically aligned liquid crystal display having negative compensation film
First Claim
1. A vertically aligned LCD (VA-LCD) in a multi-domain mode or using a chiral additive, provided with a negative compensation film, in which a vertically aligned panel (VA-panel) is obtained by injecting liquid crystal having a negative dielectric anisotropy (Δ
- ε
<
0) or a positive dielectric anisotropy (Δ
ε
>
0) into a gap between upper and lower glass substrates, upper and lower polarizing plates are arranged above the upper and lower surfaces of the VA-panel so that optical absorption axes of the polarizing plates are perpendicular to each other, and a cell gap in the range of 3 μ
m to 8 μ
m is maintained, comprising;
the negative compensation film including one or more of a first retardation film (+A-plate) satisfying the condition of nx>
ny=nz, and a first retardation film (−
A-plate) satisfying the condition of nx<
ny=nz, and one or more of a second retardation film (−
C-plate) satisfying the condition of nx=ny>
nz, for forming a liquid crystal cell, wherein said nx and ny represent in-plane refractive indexes between the VA-panel and the upper and lower polarizing plates, and said nz represents a thickness refractive index,wherein said first retardation film is arranged such that an optical axis of said first retardation film is perpendicular to an optical absorption axis of the neighboring polarizing plate, and a total thickness retardation (R−
C+RVA) including the thickness retardation of said second retardation film and the thickness retardation of the VA-panel has a negative value.
1 Assignment
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Accused Products
Abstract
The present invention relates to a vertically aligned LCD (VA-LCD) comprising a negative compensation film including one or more of a first retardation film (+A-plate) satisfying the condition of nx>ny=nz and a first retardation film (−A-plate) satisfying the condition of nx<ny=nz, and one or more of a second retardation film (−C-plate) satisfying the condition of nx=ny>nz, wherein the first retardation film is arranged such that its optical axis is perpendicular to an optical absorption axis of a neighboring polarizing plate, and a total thickness retardation (R−C+RVA) including the thickness retardation of the second retardation film and the thickness retardation of a VA-panel has a negative value. The VA-LCD in accordance with 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
15 Claims
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1. A vertically aligned LCD (VA-LCD) in a multi-domain mode or using a chiral additive, provided with a negative compensation film, in which a vertically aligned panel (VA-panel) is obtained by injecting liquid crystal having a negative dielectric anisotropy (Δ
- ε
<
0) or a positive dielectric anisotropy (Δ
ε
>
0) into a gap between upper and lower glass substrates, upper and lower polarizing plates are arranged above the upper and lower surfaces of the VA-panel so that optical absorption axes of the polarizing plates are perpendicular to each other, and a cell gap in the range of 3 μ
m to 8 μ
m is maintained, comprising;the negative compensation film including one or more of a first retardation film (+A-plate) satisfying the condition of nx>
ny=nz, and a first retardation film (−
A-plate) satisfying the condition of nx<
ny=nz, and one or more of a second retardation film (−
C-plate) satisfying the condition of nx=ny>
nz, for forming a liquid crystal cell, wherein said nx and ny represent in-plane refractive indexes between the VA-panel and the upper and lower polarizing plates, and said nz represents a thickness refractive index,wherein said first retardation film is arranged such that an optical axis of said first retardation film is perpendicular to an optical absorption axis of the neighboring polarizing plate, and a total thickness retardation (R−
C+RVA) including the thickness retardation of said second retardation film and the thickness retardation of the VA-panel has a negative value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- ε
Specification