JPS6473318A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To obtain good orientation even in a region of a large cell thickness above 3mum by using a ferroelectric liquid crystal compsn. obtd. by mixing, from a high temp. side, an isotropic liquid, a liquid crystal compd. which is of a smectic A phase and chiral smectic C phase and has 2 arom. rings and a liquid crystal compd. which has 3 arom. rings. CONSTITUTION:Such a liquid crystal material which is the mixture composed of the liquid crystal compd. having the 2 arom. rings and the liquid crystal compd. having the 3 arom. ring and the phase system of which is, from the high temp. side, the isotropic liquid, the smectic A phase and the chiral smectic C phase, is used. The molecules appearing first near the transition point from the isotropic liquid to the phase on the low temp. side are uniaxially oriented in the orientation treatment direction and the molecules appearing thereafter are uniaxially oriented among the batonne thereof while the layer structure is made. Since the smectic A phase has no spirals, etc., unlike the chiral nematic phase, the deviation of the molecular axis from the orientation is obviated even in the region where the cell thickness is larger than 3mum. The good orientation is thus obtd. without having the deviation in the layer direction even if the area is large.