Patent ID: 7434945

Claim:
An illuminating device, comprising: a light source for emitting light in red; a light source for emitting light in green; a light source for emitting light in blue; a lighting control means for lighting the three light sources in a time-dividing manner; a time-dividing optical switching element arranged for guiding the light from each light source into the same or the approximately same direction, and capable of switching either to reflect the light or to transmit the light, depending on whether or not voltage is applied to the time-dividing optical switching element; an element control means for bringing the time-dividing optical switching element into a reflecting state when a certain light source is lighted, and bringing the time-dividing optical switching element into a transmitting state when another certain light source is lighted; an optical integrator for rendering uniform intensity of light incident from each light source; and reflecting means arranged on light-emission sides of the two light sources out of the three light sources, and each configured to selectively transmit light from a respective one of the two light sources, and alternately to reflect the light from the third light source of the three.