Four-domain twisted nematic liquid crystal display fabricated by reverse rubbed polyimide process

Abstract

In Appl. Phys. Lett. 67, 1990 (1995), we proposed a particularly simple four-domain (4-D) twisted nematic(TN) liquid crystal display(LCD) device, which is composed of two left-handed and two right-handed TN subpixels. The two members of each pair of same handedness subpixels are rotated 180° with respect to each other, resulting in four domains that spatially average one another optically to provide a wide angle of viewing with no gray scale inversion. The optical performance of the 4-D TN LCD was confirmed by studies of a test cell fabricated by a two-step SiOx oblique evaporation technique. In this article, we report the realization of our four-domain TN display by a reverse rubbing technique that should be suitable for mass production in the display industry. The optical simulation of our 4-D TN cell was performed and the effect of disclinations at subpixel boundaries on display contrast investigated. A simple model was developed to evaluate the stability of our 4-D structure.