We demonstrated a high speed liquid crystal (LC) display mode based on a nonchiral smectic C LC in an antiparallel planar geometry. This mode shows analog gray scales in contrast to typical surface-stabilized ferroelectric LC mode. Fig. 1 shows the operation principle of the antiparallel planar nonchiral smectic C (APNSC) LC mode. The LC with a positive dielectric anisotropy in the smectic C phase has a constant molecular tilt angle (a) with respect to the layer normal for fixed temperature. In this APNSC LC mode, analog gray scales and wide viewing properties are achieved by means of the dielectric coupling with an external field. The molecular rotation is confined on the smectic C cone. It was found that a stepwise thermal annealing process (STAP) improves the contrast ratio and the response time. In fact, the STAP produces an initially stable LC alignment in a large area. The APNSC mode is fast enough to process dynamic image at a video rate.

This work was supported in part by Samsung Electronics, AMLCD.