Generation of pretilt angle in NLC and EO characteristics of transcription-aligned TN-LCD fabricated by transcription alignment on polyimide surfaces

Abstract

In this work, we have investigated the monodomain alignment of a nematic liquid crystal (NLC) in cells fabricated by transcription alignment on a polyimide (PI) surface with side chain. The generated pretilt angle of the NLC is about 3.7degree; it decreases with increasing rubbing time of the original substrate. It is considered that the generation of the pretilt angle in a NLC may be attributed to steric interaction of the polymer side chain. It is also suggested that LC alignment produced by transcription alignment techniques is attributable to the memory effect of the NLC on the PI surface. We also observed good voltage-transmittance characteristics for a transcription-aligned twisted nematic (TN-LCD) on a PI surface; it is almost the same as for a rubbing-aligned TN-LCD. Finally, we suggest that the slow response time characteristics of a transcription-aligned TN-LCD may be attributed to the weak anchoring strength of the NLC.