We have experimentally investigated the causes of the poor quality of alignment in antiferroelectric liquid crystals devices. The techniques for its improvement 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 used. Hence we have investigated the effect of offsetting the rubbing direction on the opposite glass plates. The evaluation of the electrooptical performance of our devices clearly shows that there exists a value of the skew, which gives virtually ideal alignment quality, with values of the extinction ratio in excess of 2000:1. By using this rubbing technique our displays show stable behaviour. © 1999 Elsevier Science B.V. All rights reserved.
Alignment of antiferroelectric liquid crystals for high contrast displays
Beccherelli R;
1999
Abstract
We have experimentally investigated the causes of the poor quality of alignment in antiferroelectric liquid crystals devices. The techniques for its improvement 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 used. Hence we have investigated the effect of offsetting the rubbing direction on the opposite glass plates. The evaluation of the electrooptical performance of our devices clearly shows that there exists a value of the skew, which gives virtually ideal alignment quality, with values of the extinction ratio in excess of 2000:1. By using this rubbing technique our displays show stable behaviour. © 1999 Elsevier Science B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
