A single plate type projector has a DMD 3 and a rotary color filter 2. The DMD 3 converts light emitted from a lamp 1 into modulated light. The rotary color filter 2 separates the emission light from the lamp 1 into plural colors by rotating a rotary region which is interposed between the lamp 1 and the DMD 3 and on which light transmittance filter segments allowing each of different colors to pass are arranged. In such a projector, there has been a trade-off relation between the brightness of the entire image and color reproducibility because the amount of light of each color and the brightness of the entire image are restricted by the rotary filter. The amount of light emitting from the lamp 1 is controlled so that the amount of light increases during a period when the light emitted from the lamp 1 passes through at least one of the plurality of filter segments in the rotary color filter 2. Consequently, the brightness of the entire image and the color reproducibility can be arbitrarily regulated by regulating the quantity of light being emitted from the lamp 1.