A first prism has first to third faces. The first face is opposing a first optical modulator. Any two planes among three planes respectively including the first to third faces intersect with each other. A second prism has fourth to sixth faces. The fourth face is provided to be in contact with the third face via a dichroic coating layer and in parallel with the third face. The fifth face is opposing a second optical modulator and in parallel with the second face. The sixth face is in opposite to the first optical modulator with respect to an optical axis of the second optical modulator. The sixth face is formed to be inclined with respect to a reference surface, such that an unnecessary transmitted light and an unnecessary reflected light of the dichroic coating layer are not totally reflected by the sixth face.