Improvement of viewing angle characteristics in a twisted-nematic liquid-crystal display by using a cholesteric liquid-crystal compensation layer

Viewing angle characteristics of a twisted nematic (TN) liquid-crystal display (LCD) have been improved by inserting a planar aligned cholesteric liquid crystal compensating layer between the TN cell and a polarizer. Dependencies of the electro-optical characteristics of the novel LCD on the retardation, ratio of thickness to the pitch (dc/p) and twist-sense in the cholesteric layer are discussed. A thin-film transistor addressed LCD with a wide viewing angle has been developed based on this novel cell construction and its display performance is reported.