Liquid crystal display device
AssigneeHitachi, Ltd.
InventorsYoshiharu Nagae, Tetsuo Ito, Masaaki Kitajima, Hideaki Kawakami, Fumio Nakano, Hidetoshi Abe, Masato Isogai, Michio Ooue, Akio Mukoh
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Abstract
A color liquid crystal display device wherein a nematic liquid crystal to which a dichroic dye and an optically active substance have been added is used as the liquid crystal layer and the amount of said optically active substance added is so selected as to fall in a range making steep the threshold voltage characteristics of the liquid crystal.
Claims6
A liquid crystal display device comprising a pair of base plates facing each other at a predetermined distance, a plurality of electrodes formed on the facing surfaces of the base plates, a liquid crystal layer placed between the base plates and means for orienting perpendicularly liquid crystal molecules provided to at least the electrode portions contacting with the liquid crystal layer, and means for driving said device by time division driving using the voltage averaging method, the liquid crystal layer comprising one or more nematic liquid crystals having a negative dielectric anisotropy, one or more dichroic dyes and one or more optically active substances, and a ratio of the thickness of the liquid crystal layer (d) to the pitch (P) in cholesteric state, d/P, being in the range of 0.6 to 1.0, whereby a liquid crystal display device having a displayed image of high contrast can be achieved.
Dependencies are inferred from the claim text.