Optical compensation for elimination of off-axis light leakage in a liquid crystal display

Optical compensation for wide viewing angle characteristics in a liquid crystal display (LCD) is essential for high-quality dark images, especially from the bisector direction of the crossed polarizers. We introduce achromatic compensation configurations for a perfect dark state in LCDs. To cancel out the effect of wavelength dispersion, we replaced each A plate in the conventional uniaxial configurations by a pair of orthogonal A plates.