AMORPHOUS TWISTED NEMATIC LIQUID-CRYSTAL DISPLAYS - THE CHARACTERISTICS AND THE THEORETICAL CONSIDERATIONS

Amorphous twisted nematic liquid crystal display cells have been prepa red without rubbing. The textures consisted of twisted nematic multi-d omains. Theoretical calculations of the optical properties of such cel ls have been carried out by the 4 X 4 matrix method. The optical aniso tropy of the liquid crystal is optimized to suppress/optimize the back ground colour. The electro-optical characteristics of the a-TN have be en measured. It is shown that the a-TN devices exhibit wide and unifor m viewing angle characteristics and possess good gray scale capability . Viewing angles of - 47 degrees to + 45 degrees (up-down) and - 51 de grees to + 46 degrees (left-right) have been achieved. A risetime of 3 6.5 ms and decay time of 35.5 ms have been measured in an a-TN sample.