Patent ID: 7815317

Claim:
A projector comprising: a light source; a light modulation device that modulates a light flux emitted from the light source on the basis of an input image signal so as to form an optical image; a projective optical device that projects the optical image formed by the light modulation device on magnified scale; an image-capturing device that captures the projection image projected on magnified scale and automatically adjusts the projection image upon installment; an image acquiring unit that acquires an image including the projection image captured by the image-capturing device during image projection; an image region separating unit that separates a projection image region and a background image region from the acquired image; a background image time-lapse change acquiring unit that acquires a time-lapse change of a background image in the separated background image region; a background image time-lapse change storage unit that stores the acquired time-lapse change of the background image; a projection image time-lapse change acquiring unit that acquires a time-lapse change of the projection image displayed on the projection image region; a projection image time-lapse change storage unit that stores the acquired time-lapse change of the projection image; an tendency-of-use judging unit that judges a tendency of use of the projector on the basis of the stored time-lapse change of the background image and the stored time-lapse change of the projection image; and a light quantity adjusting unit that adjusts a light quantity of the light source on the basis of the judgment result.