A color separation/combination optical system according to the present invention comprises of a polarization beam splitter which performs at least one of separation of illumination light from a light source into light components for a plurality of colors and combination of light components for modulated...http://www.google.com/patents/US6776489?utm_source=gb-gplus-sharePatent US6776489 - Color separation/combination optical system, image display optical system, and projection type image display apparatus
