Patent ID: 6094252
Filing Date: 2000-07-25
Classification: G02F

Abstract:
A liquid crystal display device comprising a liquid crystal cell including:a pair of substrates at least one of which has light transparency;a chiral nematic liquid crystal layer having positive anisotropy of dielectric constant, disposed between the pair of substrates;voltage applying means for applying a voltage to the liquid crystal layer; andlight reflecting means for reflecting light transmitted through the liquid crystal layer,wherein the liquid crystal cell includes a plurality of display pixels arranged in a matrix, and the voltage applying means includes a plurality of active elements for applying a voltage to the liquid crystal layer with respect to each of the display pixels,wherein the liquid crystal layer contains a pleochroic dye, and liquid crystal molecules in the liquid crystal layer are twisted with respect to a helical axis perpendicular to surfaces of the pair of substrates,wherein a twist angle of the liquid crystal molecules from one of the pair of substrates to the other of the pair of substrates is in a range selected from the group consisting of a range from about 0.degree. to about 50.degree., a range from about 140.degree. to about 250.degree., and a range of twist angles obtained by adding an integral multiple of In radians to the twist angles in the range from about 0.degree. to about 50.degree. and in the range from about 140.degree. to about 250.degree., andwherein substantially all bulk liquid crystal molecules within the liquid crystal layer rise under the applied voltage, causing the pleochroic dye to rise, so that only pleochroic dye at an interface of the pair of substrates contributes to the light absorption,thereby achieving the brightest display in the liquid crystal device.