Alignment of antiferroelectric liquid crystals for high contrast displays

We have experimentally investigated the causes of the poor quality of align ment in antiferroelectric liquid crystals devices. The techniques for its i mprovement are also evaluated. Our results show that using only one rubbed substrate may not be suitable for practical displays because of a tendency for layer rotation to occur even when a symmetrical driving waveform is use d. Hence we have investigated the effect of offsetting the rubbing directio n on the opposite glass plates. The evaluation of the electrooptical perfor mance of our devices clearly shows that there exists a value of the skew, w hich gives virtually ideal alignment quality, with values of the extinction ratio in excess of 2000:1. By using this rubbing technique our displays sh ow stable behaviour. (C) 1999 Elsevier Science B.V. All rights reserved.