Litton Systems Canada Limited

Kam H Wan

Birendra Bahadur

A wide viewing-angle twisted nematic liquid crystal display is provided. The wide viewing-angle is achieved by the application of properly aligned retardation films in between a 90.degree. twisted nematic liquid crystal cell and one of two polarizers, as well by doping the liquid crystal with an appropriate amount of dichroic dye molecules. These two additional elements not only increase the viewing-angle but also improve the chromaticity of the display. The retardation films convert the polarization state of the transmitted light of the liquid crystal cell to a more linearly polarized light in order to achieve higher contrast ratio at -45.degree. and +45.degree. scanning direction relative to the rub direction of the back substrate of the cell. The dichroic dye molecules operate on the absorption principle and further improve the contrast ratio along a 90.degree. scanning direction. By combining both elements in a liquid crystal display, a much wider viewing-angle is achieved.

Growing community of inventors

Mississauga, Canada

Kam H Wan