High contrast distorted helix effect electro-optic devices and tight ferroelectric pitch ferroelectric pitch ferroelectric liquid crystal compositions useful therein

摘要

Ferroelectric Liquid Crystals (FLCs) which exhibit a ferroelectric phase and a chiral nematic phase at temperatures above the ferroelectric phase are provided. The natural helix pitch of the FLC in the ferroelectric phase of these materials is sufficiently tighter than the thickness of the FLC layer such that it is not surface-stabilized. The chiral nematic phase has a natural helix pitch sufficiently greater than the cell thickness to facilitate alignment of the FLC in an FLC device to achieve high contrast. The FLCs of this invention are useful in making fast response, high contrast FLC electro-optic devices in which the FLC retains a helical director structure stable to unwinding.