LIQUID CRYSTAL DISPLAY DEVICE AND PHASE PLATE THEREFOR

摘要

A liquid crystal display device comprising: a liquid crystal display element formed by holding, between two substrates at least one of which has a light-permeable electrode, a liquid crystal layer in which liquid crystal molecules of a nematic liquid crystal having positive dielectric anisotropy and containing an optically active substance has a helical axis perpendicular to the substrates between the substrates and are helically oriented, and the liquid crystal molecules between the substrates have a twist angle of 180 to 270 degrees, and a phase plate formed by stacking water surface development films of an organic polymer with changing the orientation axes thereof at a constant angle, wherein the contrast ratio, a ratio between brightness in white display and brightness in black display, is remarkably excellent over that of a device obtained by stacking plastic films, and the transmissivity, a quotient of background brightness and light source brightness, is equivalent to that of a conventional double layer structure liquid crystal display device.