Low voltage and wide-viewing-angle twisted nematic liquid crystal displays by optical compensation

Abstract

Low voltage and wide-viewing-angle single-domain and two-domain twisted nematic liquid crystal displays (TN-LCDs) can be achieved by using a single-layer twist discotic film with negative birefringence as a compensation film. The compensated TNs have also higher contrast ratio and less color-shifts over the uncompensated ones. The compensated two-domain TN has the added advantage of no extra light leakage at the locations of the disclination lines between two domains in the dark state of the display so that no black matrix is needed at these locations. Further increases in viewing angles are also possible by combining the compensation scheme with wide-viewing-angle polarizers. The compensation scheme can also be applied to reflective TNs for either direct-view or projection displays.