| 摘要 |
PURPOSE: To provide a liquid crystal display element with which liquid crystal molecules are stably oriented and hysteresis is small and for which dichromatic dyes are used by constituting the element of a pair of respective specific substrates and liquid crystals of a chiral nematic phase. CONSTITUTION: This liquid crystal display element is composed of a piar of the substrates 11, 12 arranged to face each other and the nematic liquid crystals 13 enclosed between these substrates 11 and 12. The liquid crystals 13 and composed of the nematic liquid crystals which are added with chiral liquid crystals and have positive dielectric constant anisotropy. The liquid crystals are enclosed between the substrates 11 and 12 in a state twisted by 300 to 90 deg. according to the orientation treatments subjected to oriented films 16, 17. Further, dichromatic dyes of different colors are added thereto. The ratio D/P of the thickness D[μm] of the layer of the liquid crystals 13 and the spiral pitch (bulk state) P[μm] and the twist angle θ (radian) of the liquid crystal molecules 13A satisfy formula θ/2π-1/4<D/P<θ/2π. As a result, the hysteresis is small and the stepwise change of transmittance by changing impressed voltage is possible. |
