Novel Ferroelectric Liquid Crystal Mode for Active Matrix Liquid Crystal Display Using Cholesteric–Chiral Smectic C Phase Transition Material

Abstract

We propose a novel ferroelectric liquid crystal (FLC) mode which is capable of gray-scale display with an active device such as a thin-film transistor (TFT). This technology is based on the monostable FLC mode, which is obtained from a material with cholesteric–chiral smectic C (Ch–SmC*) phase transition sequences and by applying a low DC voltage only near the phase transition temperature from Ch to SmC* for making the layer normal direction uniform. The electrooptical response of liquid crystal molecules under AC voltage is asymmetric between plus and minus voltages. It shows characteristics such as low spontaneous polarization (PS) value, short response time, small temperature dependence and wide tolerance to cell gap nonuniformity. Furthermore, we made TFT prototype panels using this mode. We could confirm this mode, realizing high-quality moving pictures without blurring based on the nonholding display and good color reproducibility based on the field sequential color method.