LIQUID CRYSTAL DISPLAY DEVICE WITH BIREFRINGENCE COMPENSATOR

摘要

The invention concerns a liquid crystal display device comprising a type II twisted nematic liquid crystal screen (1). The screen is provided on at least one of its main surfaces (10, 11) with a film (2) having biaxial birefringence with refractive index anisotropy and a film (3) having optical axis uniaxial birefringence slanting with respect to the liquid crystal screen. Preferably, the biaxial film (2) is a drawn plastic film and the uniaxial film (3) is a holographic grating. Moreover, a biaxial film (2, 2') and an uniaxial film (3, 3') are provided on each side of the screen. The assembly is placed between cross polarizers (4, 4'). The relative orientations of the different screen components are clearly defined. The invention is useful for increasing horizontally and vertically a liquid crystal screen viewing angles.