JPS6442632A - Liquid crystal device - Google Patents

Abstract

PURPOSE:To prevent the reduction of the contrast ratio in the titled device, by specifying the product of the thickness of a liquid crystal layer and the refractive index anisotropy of a liquid crystal. CONSTITUTION:The orientation surfaces of substrate 11a and 11b are disposed opposingly, and the orientation direction 16a of an orientation film 13a and that 16b of the orientation film 13b are specified in such way that a liquid crystal molecule 14 has a twisted helical structure 15 of 220 deg.-250 deg.. The substrate are disposed in parallel with each other with such a space that the product DELTAnXd is in a range of 0.6mum-0.75mum wherein (d) is the thickness (mum) of the liquid crystal layer and DELTAn is the refractive index anisotropy of the liquid crystal. A nematic liquid crystal 17 which has the positive dielectric constant and contains an optical active additive, is injected into the space formed between the two substrate plates. And, pair of polarizing plates 18a and 18b are disposed on the outside of the two substrates respectively in such way that the angles between the translucent axis or the absorption axis of said polarizing plates 18a and 18b and the orientation directions 16a and 16b of the liquid crystal molecule are 20 deg.-40 deg. and 60 deg.-80 deg. respectively. Thus, the base color of the titled device is permitted to approach a white color, thereby obtaining the titled device with the high image quality.