Optically compensated circular polarizers for liquid crystal displays

An optical compensation principle of the crossed circular polarizers is developed to widen the viewing angle of high-transmittance multi-domain vertical-alignment liquid crystal displays (MVA-LCDs). The optical properties of a biaxial film are analyzed by the Berreman 4x4 matrix method, and the analytical solution for the slow-axis orientation of a biaxial film is calculated to obtain the compensation principle of the crossed circular polarizers. Based on this compensation principle, the high-transmittance MVA-LCD theoretically has a complete 80 degrees viewing cone for contrast ratio (CR)>100:1 and experimental results reveal that the compensated high-transmittance MVA-LCD can achieve a viewing angle of over the entire 80 degrees viewing cone for CR>20:1. Practical application as a mobile display is emphasized.