Influences of Alignment Materials and LC Layer Thickness on AC Field-Stabilization Phenomena of Ferroelectric Liquid Crystals

The influences of alignment materials and LC layer thickness on an AC-field stabilization phenomena have been studied. Ferroelectric LC material with a dielectric anisotropy of -2.7 and two kinds of polyimide resins (A,B) for alignment materials were prepared. Polyimide resin A has a rigid structure and its molecular chain is rod-like, while polyimide resin B has a somewhat zigzag structure and a molecular chain which is flexibly coiled. The amplitude E h of an AC electric field which is necessary for stabilizing LC molecules was measured and the following results were obtained: (1) E h of the LC cell using polyimide resin B was smaller than that of the LC cell using polyimide resin A. (2) As the LC layer thickness became smaller, the amplitude of E h became larger.