JPS6433522A - Twisted nematic type liquid crystal display device - Google Patents

Abstract

PURPOSE:To eliminate the defective display based on the fluctuation in an operating temp. by incorporating a cyclohexane liquid crystal into a nematic liquid crystal and specifying the relations between the spiral pitch of the liquid crystal, the thickness of the liquid crystal layer and angle. CONSTITUTION:This display device consists of the liquid crystal cell which is disposed with a pair of substrates 1, 2 formed with oriented films 5, 6 subjected to a rubbing treatment on the electrodes so as to face each other, is interposed with the nematic liquid crystal added with an optically active material so as to have positive dielectric constant anisotropy between a pair of said substrates and has the spiral structure in which the orientation direction of the liquid crystal molecules is twisted by a prescribed angle phi between the planes of both substrates. The nematic liquid crystal consists of the liquid crystal contg. preferably >=20wt.% cyclohexane liquid crystal expressed by the formula I. The angle phi thereof is set at 210 deg.<=phi<=300 deg. under the conditions under which the thickness (d) of the liquid crystal layer satisfies (phi/360 deg.-1/4)<d/p<phi/360 deg. with respect to the spiral pitch (p) of the liquid crystal. The stable display as against the fluctuation in the temp. is thereby enabled.