Crossover frequencies and turn-off time reduction scheme for twisted nematic liquid crystal displays

Abstract

The sign change of dielectric anisotropy at the characteristic crossover frequency of a nematic mixture is utilized in twisted nematic liquid crystal displays for turn-off (decay) time reduction. This can be obtained by either (a) a two-frequency addressing or (b) a high-frequency erasing scheme where the high frequency is above the crossover frequency. Data are presented on Eastman Kodak 11900 nematic mixture.