
A projector includes a super-high pressure mercury lamp a spatial light-modulator that modulates a light from the super-high mercury lamp based on an image signal, a projection lens that projects the light modulated, and an optical filter that is used to insert a prism group in the optical path and to remove the prism group that is inserted in the optical path, and a position fixing part that makes a relative-angle between each spatial light-modulator and the prism group constant.











