Patent ID: 7667825

Claim:
A projector comprising: a projection unit that projects image light on a projection screen, the projection unit comprising a light source, an SOM (Spatial Optical Modulator), and a projection lens; an optical modulator that modulates an intensity of the image light to be projected by the projection unit; a photoreception unit that receives a portion of the image light reflected by a point on the projection screen; and a distance measurement unit that detects a phase difference at the photoreception unit between the image light projected by the projection unit and the portion of the image light reflected by the point on the screen, and that measures a distance from the projector to the point on the projection screen based on the phase difference detected, wherein the projector projects the image light, produced by the light source and the SOM, through the projection lens on the projection screen, thereby displaying an image; and wherein in the distance measurement: (i) the image light produced by the light source and the SOM is projected through the projection lens; and (ii) the portion of the projected image light reflected by the point on the projection screen is received, thereby acquiring the distance from the projector to the point on the projection screen.