Optical system with polarization elements and multiple light valves

An optical system, comprising:

• a first optical system including a polarization conversion element that aligns a polarization direction of light including multiple color light beams with a predetermined polarization direction, the first optical system generating illumination light including the multiple color light beams;
• a first polarization rotation element which is disposed at a first pupil position inside the first optical system and includes a first divided region and a second divided region, and in which the first divided region and the second divided region have polarization characteristics different from each other with respect to a first color light beam of the multiple color light beams outputted from the polarization conversion element;
• a polarizer disposed between the polarization conversion element and the first polarization rotation element inside the first optical system, the polarizer reducing light in a polarization direction other than the predetermined polarization direction of the multiple color light beams included in light outputted from the polarization conversion element;
• and
• multiple light valves each illuminated by at least the first color light beam of the multiple color light beams included in the illumination light generated by the first optical system.