Patent ID: 7804567
Filing Date: 2010-09-28
Classification: G02F

Abstract:
1. A normally-white liquid crystal display (LCD) device comprising a first polarization film, a first optical compensation film, a first substrate, a first transparent electrode, a first orientation film, a twisted-nematic liquid crystal (LC) layer, a second orientation film, a second transparent electrode, a second substrate, a second optical compensation film, and a second polarization film, which are consecutively disposed in a direction of light transmission, wherein: said first polarization film has a polarization axis perpendicular to a polarization axis of said second polarization film; an optical axis of said first optical compensation film projected onto a substrate surface of said first or second substrate is substantially parallel to a longer axis of a first equivalent refractive index ellipsoid projected onto said substrate surface, said first equivalent refractive index ellipsoid representing a residual retardation of said LC layer in a vicinity of a first interface of said LC layer with respect to said first substrate upon display of black color by applying a first voltage between said first transparent substrate and said second transparent substrate to determine an orientation of LC molecules in said LC layer; and an optical axis of said second optical polarization film projected onto said substrate surface is substantially parallel to a longer axis of a second equivalent refractive index ellipsoid projected onto said substrate surface, said second equivalent refractive index ellipsoid representing a residual retardation of said LC layer in a vicinity of a second interface of said LC layer with respect to said second substrate upon said display of black color, wherein said first optical compensation film comprises a plurality of LC layers each compensating a retardation of distinct LC molecules within a first portion of said LC layer on the first substrate side of said LC layer with each of said plurality of compensation film LC layers having an optical axis generally parallel to a long axis of the respective distinct LC molecule, and said second optical compensation film comprises a plurality of LC layers each compensating a retardation of distinct LC molecules within a second portion of said LC layer on the second substrate side of said LC layer with each of said plurality of compensation film LC layers having an optical axis generally parallel to a long axis of the respective distinct LC molecule, and wherein the following relationship: 0.5×θTw−47.5≦Δθ2≦0.5×θTw−43.8 holds, where θTw is a twisted angle of said LC layer, Δθ