Patent ID: 7559658

Claim:
A projector comprising: a light modulating device which modulates light beams emitted from a light source according to image information to form an optical image; a projection optical device which enlarges and projects the optical image onto a screen, the projection optical device including a projection lens which has a plurality of lenses and enlarges and projects the optical image onto the screen by means of the plurality of lenses; and a focal position changing unit which changes a focal position, which is a relative position of the plurality of lenses, to perform focus adjustment on the image enlarged and projected onto the screen; a setting input unit through which automatic adjustment information for changing the focal position to an in-focus position where the projected image is in an in-focus state is input; and a focus adjustment control unit which performs automatic adjustment control in which the focal position changing unit is driven until the projected image is in the in-focus state to change the focal position, on the basis of the automatic adjustment information, and when a variable range is defined as a range in which the focal position can be changed from a near end where the projected image can be adjusted to the in-focus state when a projection distance to the screen is short to a far end where the projected image can be adjusted to the in-focus state when the projection distance to the screen is long, the variable range in the automatic adjustment control is set to be narrower than a variable range where the relative position of the plurality of lenses can be mechanically changed, wherein the variable range in the automatic adjustment control is set to a range from a tele-end-side zoom position, where the projected image has a minimum image contour, to a wide-end-side zoom position where the projected image has a maximum image countour, and wherein the variable range in the automatic adjustment control is set to be narrower at the far end than the variable range where the focal position can be mechanically changed.