To reduce the loss in light by providing a reflection mirror reflecting the light after separating it to three primary colors and a monochromatic picture display device reflecting primary color pictures corresponding to the respective primary colors.

The rotating reflection mirror 4 and the monochromatic picture display device (DMD) 5 are disposed on the optical axis (k) of a light source 1 condensed on a projection lens 3. The mirror 4 is hexagonal pillar mirror consisting of an R reflection mirror reflecting only R(red) light out of three primary color light, a G reflection mirror reflecting only G(green) light, and a B reflection mirror reflecting only B (blue) light. Mirror surface forming respective surfaces are the R, G and B reflection mirrors and six surfaces are arranged counterclockwise in this order. The mirror 4 is rotated in a direction shown by an arrow centering a rotating shaft 4a passing through a center axis and the light from the light source 1 is successively separated to three primary colors R, G and B and reflected. The DMD 5 successively reflects the primary color picture corresponding to each of three primary colors of the light separated and reflected by the mirror 4. The respective primary color pictures of R, G and B successively reflected are projected to a screen by the lens 3.