ALIGNMENT LAYERS FOR FERRO AND ANTIFERROELECTRIC LIQUID-CRYSTAL CELLS

Aromatic fluorine and nonfluorine containing polyimides, polyamide-imides and polyamides were developed and utilized as alignment layers in ferroelectric (FLC) and antiferroelectric liquid crystal (AFLC) cells. The FLC and AFLC blend (AFLCB-1) of liquid crystals used in the experiment were CS-1011 and [S(-)4-(1-methylheptyloxycarbonyl) phenyl-4-octyloxybiphenyl-4-carboxylate (MHPOBC), R(+)4-(1-trifluoromethylheptyloxy carbonyl)phenyl-4-octyloxybiphenyl-4-carboxylate (TFMHPOBC), and other homologues, [AFLCB-1], respectively. The alignment layer deposited over an ITO-coated glass electrode plate with 2 mum cell gap showed good or random alignment of liquid crystal in FLC and AFLC cells. The AFLC cells exhibited contrast ratio values greater than 10:1 depending on the molecular structure of the alignment layer. The alignment quality of FLC and AFLC cells was also compared by using different molecular structure of polymer alignment layers.