Supertwist liquid crystal display includes a nematic liquid crystal mixture with different dielectric anisotropies

摘要

Supertwist liquid crystal display comprises two support plates forming a cell and a nematic liquid crystal mixture in one cell and with positive dielectric anisotropy; electrode layers with orientation layers on the inside of the supports; an angle of incidence of 0-30 deg between the longitudinal axis of the molecules at the support surface and the support plates; and a twisting angle from orientation layer to orientation layer of 22.5-600 deg . The nematic liquid crystal mixture is specified. The nematic liquid crystal mixture comprises: (A) 15-90 wt.% of liquid crystal compound(s) of dielectric anisotropy above +1.5; (B) 0-60 wt.% of liquid crystal compound(s) of dielectric anisotropy between -1.5 and +1.5; (C) 0-20 wt.% of liquid crystal compound(s) of dielectric anisotropy below -1.5; (D) an optically active component giving a ratio of layer thickness and natural pitch of the chiral nematic liquid crystal mixture of 0.2-1.3; (E) a compound of formula (IA); and (F) a compound of formula (IB). Ra and Rc = H or 1-7C alkyl; Rb = 1-10C alkyl or alkoxy or 2-10C alkenyl(oxy); n and p = 0, 1 or 2; Rd = F, OCH3, 1-7C alkyl or alkoxy or 2-7C alkenyl(oxy); Y<1> and Y<2> = H or F; and q = 0 or 1