OPTICAL SYSTEM AND PROJECTION TYPE DISPLAY DEVICE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a durable color separation/synthesis optical system and a projection type display device using the same capable of projecting high contrast images.SOLUTION: A color separation/synthesis optical system 100 comprises a synthesizing prism 17 which synthesizes green light and red and blue light and a polarization separation surface 14a having red and blue light polarization separation characteristics which synthesizes red and blue light reflected from respective image modulator elements and guides the synthesized light to the synthesizing means. The synthesizing prism 17 guides P polarized light in the red light to a projection lens 18 and guides both of P polarized light and S polarized light in the blue light to the projection lens 18. The polarization separation surface 14a has the higher polarization separation characteristic for S polarized light than the polarization separation characteristic for P polarized light and receives S polarized light in the blue light at a black display state.