Color-separation/synthesis optical system with particular cut-off wavelengths and emission-side polarizer and projection type liquid crystal display device using the same

摘要

The present invention provides a projection type liquid crystal display device capable of achieving a high contrast ratio without causing optical leakage on boundary wavelength regions of three color light components in the case of a black display. The projection type liquid crystal display device is provided with a first and a second retarder stacks each of which has cut-off wavelengths. The cut-off wavelength on the short wavelength side of the first retarder stack is placed on a shorter wavelength side as compared with the cut-off wavelength on the short wavelength side of the second retarder stack, and the cut-off wavelength on the long wavelength side of the first retarder stack is placed on a longer wavelength side as compared with the cut-off wavelength on the long wavelength side of the second retarder stack.