Illuminating optical device, projector and method of controlling an illuminating optical device

Abstract

Provided is an illuminating optical device that can reduce lowering of luminance in a display mode for enhancing color reproducibility. A multiple number of light source units () each emit a different color of light. Color wheel () includes multiple transmissive regions that each transmit a different color of light and that moves the point on which the incident light from each light source unit falls, over the transmissive regions as the wheel rotates. A storage () stores a multiple number of lighting pattern information items each item providing a lighting pattern to turn on each light source unit in a different period of lighting. A controller () receives a select signal for selecting one of the multiple lighting patterns to turn on each light source unit in accordance with the lighting pattern information that provides the lighting pattern selected by the select signal.