Patent ID: 6111631
Filing Date: 2000-08-29
Classification: C09K,G02F

Abstract:
A liquid crystal cell having a ferroelectric, chiral smectic, birefringent liquid crystal layer and at least one polarizer, the cell having a pair of parallel plates which enclose the liquid crystal layer and each of which is provided with a surface structure orienting the molecules of the liquid crystal layer and at least one electrode for generating an electric field with a voltage U, and the liquid crystal layer having a layer thickness d and a saturated switching angle .alpha., wherein the layer thickness d is smaller than the helix pitch p of the liquid crystal layer, wherein the saturated switching angle .alpha. is sufficient to give rise to linear liquid crystal domains and the liquid crystal layer, upon cooling from an isotropic phase, forms a cholesteric N phase before the S.sub.c * phase, wherein the optical path difference .DELTA.n.multidot.d.sub.eff of the cell at U=0 is greater than in the saturated state, .DELTA.n being the birefringence and d.sub.eff the distance covered by the light in the liquid crystal between a polarizer and an analyzer, and wherein the current-voltage characteristic of the cell has two maxima, one for U>0 and one for U<0.