EXPERIMENTAL RESEARCH OF AMORPHOUS TWISTED NEMATIC LIQUID-CRYSTAL DISPLAYS

Amorphous twisted nematic liquid crystal display(a-TN) cells have been prepared without rubbing. The liquid crystal is injected into the cel l in the isotropic phase and then cooled down to the nematic phase. Th e cooling rate and the uniformity are critical for the preparation of the a-THs. Nematic liquid crystals, bath with and without chiral dopan t, have been used for the a-TNs. The electro-optical characteristics o f the a-TN have been measured. Theoretical calculations have been carr ied out by 4 X 4 matrix method. A rising time of 700 mu s a and a decr easing time of 48ms have been detected. It is shown that the a-TN devi ces exhibit wide and uniform viewing angle characteristics. a viewing angle of +/- 30 degrees has been achieved.