Ferroelectric Liquid Crystal Display with High Contrast Ratio

To obtain zig-zag defect-free liquid crystal cells by means of a standard rubbing technique, the effect of a new polyimide film on pretilt angle at a surface has been investigated. This new polyimide imposes the high pretilt over wide rubbing density, and good orientation of liquid crystals without zig-zag defects can be obtained for rubbing densities higher than 0.5×103. A new driving scheme to realize display devices with a high contrast ratio is proposed. This scheme is devised by utilizing anomalous switching behavior and AC-stabilized effect. The prototype of the ferroelectric liquid crystal display device shows the maximum contrast ratio of 40:1.