Patent ID: 6532052
Filing Date: 2003-03-11
Classification: G02F

Abstract:
A liquid crystal display device comprising:chiral nematic liquid crystal material having positive dielectric anisotropy; cell wall structure that contains said liquid crystal material; at least one alignment surface that is effective to substantially homogeneously align the liquid crystal director adjacent thereto, wherein at least one of said cell wall structure and each said alignment surface cooperates with said liquid crystal material so as to form focal conic and planar textures that are stable in the absence of a field, each said alignment surface being effective to provide at least one of the following: (a) a brightness at a wavelength of peak reflection of said planar texture that is increased by at least 5% as compared to an identical liquid crystal device but with inhomogeneous alignment surfaces, (b) the focal conic texture with a reflectance that does not exceed 10% of electromagnetic radiation incident on the display device at a wavelength of peak reflection of the planar texture, and (c) a degree of circular polarization at a wavelength of peak reflection of the planar texture, which is increased by at least 10% as compared to an identical liquid crystal device but with inhomogeneous alignment surfaces; and means for applying an electric field to transform said liquid crystal material to at least one of the focal conic and planar textures.