A projector for separating white light into three primary colors, forming images with liquid crystal light valves, mixing these images, and projecting an enlarged picture of the mixed images with a projection lens. The projector includes an optical unit having a light source, a plurality of dichroic mirrors for separating the white light into blue, green, and red beams, respective liquid crystal light valves forming images of the blue, green, and red colors. The optical unit has a chassis with a rigid center portion at which one of the liquid crystal light valves is mounted, the other two light valves being mounted symmetrically with respect thereto. An adjustment mechanism is provided for matching pixels of the second and third color valves with those of the first color valve. The red color liquid crystal light valve is disposed midway between the blue and green color liquid crystal light valves and a cooling fan is disposed below the red color liquid crystal light valve.