The present invention provides a projector that surely reduces or prevents the deformation of a lens cap even when the cap is placed on a projection lens while a lamp is on, without powering off the lamp. A projector according to the invention includes a lamp, liquid crystal panels that modulate light from the lamp, a projection lens that projects the modulated light, a lens cap that protects the projection lens, a detector that detects the lens cap on the projection lens, and a projected display controller that controls the liquid crystal panels so as to block or reduce the light from the lamp if the lens cap is found to be detected based on a signal from the detector.