ALIGNMENT CONTROL OF LIQUID-CRYSTAL MOLECULES USING PHOTO-DIMERIZATION REACTION OF POLY(VINYL CINNAMATE)

We have studied liquid crystal (LC) alignment on UV-irradiated poly (v inyl cinnamate) (PVCi) films by using the texture observations and the anchoring energy measurements. Irradiation of the PVCi films with lin early-polarized UV light creates the optical anisotropy in the films, and the anisotropy can well align LCs perpendicular to the UV polariza tion. We discuss the LC alignment mechanisms and point out the importa nt contribution from non-dimerized side chains of PVCi molecules. The anchoring energies on photo-processed PVCi films are shown to be small er than those on conventional rubbed polyimide films. We propose a new method to generate pretilt angle on the photo-processed PVCi films, a nd successful results of pretilt angle generation are demonstrated. Th is method is applied to fabricate TN- and super-multidomain TN-LCDs, a nd the good electro-optical performance of the LCDs is confirmed.