Control of gray scale inversion in a film-compensated twisted nematic liquid crystal display using beam steering optical film

Commercially available, twisted nematic (TN), liquid crystal cells have intrinsic problems such as light leakage in the dark state, gray scale inversion, and brightness nonuniformity in gray scales when the viewing direction deviates from the normal axis. Film compensation of a TN cell has solved the first problem but the second remains unsolved, which has hindered its applications to large displays. This letter proposes the use of a beam steering film to prepare a TN cell free of gray scale inversion in wide viewing directions.