Patent ID: 7837331

Claim:
An illuminator comprising: a light source that outputs light; a polarization separation device that separates the light outputted from the light source into polarization components of the first and second oscillation directions, the polarization components having mutually orthogonal polarizations, the polarization separation device includes a reflective polarizer that transmits the polarization component of the first oscillation direction and reflects the polarization component of the second oscillation direction; a reflector that reflects the polarization component of the first oscillation direction passing through the reflective polarizer, the reflective polarizer and the reflector are arranged to have different slopes from each other in a plane including a normal line of the reflective polarizer and a normal line of the reflector; and a polarization conversion device that converts the polarization component of the second oscillation direction divided by the polarization separation device to the polarization component of the first oscillation direction, wherein the polarization component of the first oscillation direction divided by the polarization separation device and the polarization component of the first oscillation direction converted by the polarization conversion device are incident on an incident surface of an illumination target from different directions from each other.