| 摘要 |
PROBLEM TO BE SOLVED: To obtain a reflection liquid crystal display device having enough wide visibility angle characteristics by forming a liquid crystal layer in such a manner that when the Poincare sphere representing the state of the polarized light by the liquid crystal layer is observed on a plane along a certain cross section, a plurality of points of Stokes parameters for the reflected light are present on an almost straight line, and that the relation of the liquid crystal layer and a phase difference film for the reflected light substantially satisfies a specified formula. SOLUTION: The phase difference film is formed to satisfy cRet(λ)=λθ(λ), wherein c is a constant, Ret(λ) is the retardation of the phase difference film for light at wavelength λ. By forming the phase difference film according to the aforementioned condition, the reflected light passed through the liquid crystal layer and the phase difference film is changed into linearly polarized light. This is because all points of Stokes parameters after the light passes through the liquid crystal layer are present on S4 axis when the light passes through the phase difference film. Therefore, the obtd. reflection type liquid crystal display has complete brightness for black color and high contrast. |
