Phase retarder comprising two optically anisotropic layers

摘要

A phase retarder comprises two optically anisotropic layers A & B. The optically anisotropic layer A essentially gives the phase retardation of pi at wavelength of 550 nm, and the optically anisotropic layer B essentially gives the phase retardation of pi/2 at wavelength of 550 nm. The layers A and B are laminated so that the retarder has such an optical characteristic that a retardation value per wavelength is within the range of 0.2 to 0.3 at each wavelength of 450 nm, 550 nm and 650 nm. The total thickness of the layers A and B is within the range of 500 nm to 20 mum.