Patent ID: 6646701
Filing Date: 2003-11-11
Classification: G02F

Abstract:
A liquid crystal display, comprising:a vertically aligned liquid crystal cell having first and second surfaces that extend opposite each other and comprising a liquid crystal material having negative dielectric anisotropy; first and second polarizers attached to the first and second surfaces of the liquid crystal cell, respectively; and a first a-plate compensation film and a first c-plate compensation film disposed between the first surface of the liquid crystal cell and the first polarizer; wherein a direction having a largest refractive index in the first a-plate compensation film is parallel to or perpendicular to a polarizing direction of the first polarizer; and wherein a difference between a summation of a retardation (nxa1âˆ’nza1)Ã—da1 of the first a-plate compensation film, a retardation (nxc1âˆ’nzc1)Ã—dc1 of the first c-plate compensation film and a retardation of the first and the second polarizers and a retardation due to birefringence of the liquid crystal cell is equal to or less than 15% of the retardation value due to birefringence of the liquid crystal cell, where a z-axis is perpendicular to the first surface of the liquid crystal cell, an x-axis is the same direction as a direction having a largest refractive index in the first a-plate compensation film, nxa1, nza1, nxc1 and nzc1 are respectively the refractive indices along the x-axis and the z-axis of the first a-plate and of the first c-plate compensation films, and da1 and dc1 are thicknesses of the first a-plate and the first c-plate compensation films, respectively.