Patent ID: 9638957
Date: 2017-05-02
CPC Classifications: G02F

Claim:
1. A liquid crystal display provided with viewing angle compensation, comprising: a liquid crystal cell in a vertical alignment mode; an upper polarizer sheet and a lower polarizer sheet, which are disposed on an upperside and an underside of the liquid crystal cell respectively; a first biaxial compensation film provided between the liquid crystal cell and the lower polarizer sheet; a second biaxial compensation film provided between the liquid crystal cell and the upper polarizer sheet; and a monoaxial compensation film provided at the upperside and/or underside of the liquid crystal cell, wherein retardation of the monoaxial compensation film as a whole is equal to liquid crystal retardation of the liquid crystal cell in a dark-state; retardation of the first biaxial compensation film is Ro=(nx−ny)×d=λ/2, and an aspect ratio value of the first biaxial compensation film is Nz=(nx−nz)/(nx−ny)=0.25; retardation of the second biaxial compensation film is Ro=(nx−ny)×d=λ/2,and an aspect ratio value of the second biaxial compensation film is Nz=(nx−nz)/(nx−ny)=0.75; wherein nx is a refractive index in an X-axis direction of the first and second biaxial compensation films; ray is a refractive index in a Y-axis direction of the first and second biaxial compensation films; nz is a refractive index in a thickness direction of the first and second biaxial compensation films; λ is wavelength, d is a thickness of the first and second biaxial compensation films; the monoaxial compensation film comprises a first monoaxial compensation film provided between the liquid crystal cell and the first biaxial compensation film and a second monoaxial compensation film provided between the liquid crystal cell and the second biaxial compensation film; retardation of each of the first and second monoaxial compensation films is equal to half of liquid crystal retardation of the liquid crystal cell in a dark-state; and a slow axis of the first biaxial compensation film is orthogonal to an absorption axis direction of the lower polarizer sheet, and a slow axis direction of the second biaxial compensation film is parallel to an absorption axis direction of the upper polarizer sheet; or a slow axis direction of the first biaxial compensation film is parallel to an absorption axis direction of the lower polarizer sheet, and a slow axis direction of the second biaxial compensation film is orthogonal to an absorption axis direction of the upper polarizer sheet; or a slow axis direction of the first biaxial compensation film is parallel to an absorption axis direction of the lower polarizer sheet, and a slow axis direction of the second biaxial compensation film is parallel to an absorption axis direction of the upper polarizer sheet; or a slow axis direction of the first biaxial compensation film is orthogonal to an absorption axis direction of the lower polarizer sheet, and a slow axis direction of the second biaxial compensation film is orthogonal to an absorption axis direction of the upper polarizer sheet; a range for the liquid crystal retardation is 80 nm<R(LC)<600 nm.