Chiral smectic liquid crystal device and display apparatus

Abstract

A liquid crystal device showing improved uniform alignment characteristic and switching characteristic is constituted by a pair of an upper substrate and a lower substrate, and a chiral smectic liquid crystal disposed between the upper and lower substrates. Each of the upper and lower substrates has thereon an electrode for applying a voltage to the liquid crystal and a uniaxial alignment film. The alignment films on the upper and lower substrates are provided with uniaxial alignment axes which cross each other so that the direction of crossing of the uniaxial alignment axes from the lower substrate to the upper substrate is identical to the direction of helical twist in cholesteric phase of the chiral smectic liquid crystal, and the chiral smectic liquid crystal is disposed in such an alignment state that the liquid crystal shows a pretilt angle .alpha., a cone angle H, an inclination angle .delta. of SmC.sup.* layer, and an apparent tilt angle .theta.a satisfying relationships of: H<.alpha.+.delta. and H>.theta.a>H/2. The crossing direction may preferably have a polarity (taken as 'positive' in clockwise direction and 'negative' in anticlockwise direction) which is the same as the polarity of the spontaneous polarization of the liquid crystal.