Masumi Okamoto

Dependence of pretilt angle on the topography of substrate in liquid crystal alignment brought about by rubbing technique

It was found that the pretilt angle of a liquid crystal alignment brought about using the rubbing technique depends upon the surface topography of substrate. The presence of small projections on the substrate was found to increase the pretilt angle of a liquid crystal alignment. It was found that the pretilt angle depends upon the projection shape and its relationship with the rubbing direction.

Pretilt-angle control of liquid-crystal alignment by using projections on substrate surfaces for dual-domain TN-LCD

— It was found that the value of the pretilt angle of liquid-crystal alignment achieved by a rubbing technique increases when small projections are present on the substrate surface. A dual-domain TN-LCD with very small dc offset voltage across the LC layer was realized by utilizing triangular-shaped projections.

Quantitative comparison of LCD viewing-angle improvement brought about by various methods

— In this paper, we quantitatively compare the viewing-angle improvement of LCDs brought about by using various methods proposed by different researchers. We used the Iso-REC (iso-reverse image, excessively dark/bright image, and contrast ratio) method for this comparison. From this comparison, it was found that dual-domain LCDs and optically compensated birefringence (OCB) LCDs have preferable viewing-angle characteristics.