Patent ID: 7635190

Claim:
A projector comprising: a light source; an optical modulation device that modulates light beam emitted from the light source in accordance with image information to form an optical image; a projection optical device that projects the optical image formed by the optical modulation device in an enlarged manner; and a projection position adjusting device that moves the projection optical device in a plane perpendicular to a projection direction to adjust the projection position of the projection optical device; wherein, the projection position adjusting device includes: a fixed member fixed to the projector; a moving member capable of moving along the plane perpendicular to the projection direction with respect to the fixed member; a dial knob supported rotatably with respect to the fixed member and operable by a user; a drive mechanism that is engaged with the moving member and the dial knob, and transmits rotation of the dial knob to the moving member to move the moving member; and a reference position detecting mechanism that is disposed between the fixed member and the dial knob, and detects a projection reference position of the projection optical device, the reference position detecting mechanism including: a spiral rail guiding section provided to a side face of the dial knob adjacent to the fixed member, along the rotational direction of the dial knob, and having a groove shape, the spiral rail guiding section having a rotation stopper configured to stop rotation of the dial knob at a position corresponding to a moving termination position of the moving member; a sliding section that is provided to the fixed member, and slides in the guiding section in accordance with the rotation of the dial knob; and an engaging section that is provided to the guiding section, and engages with the sliding section in the case in which the projection position of the projection optical device reaches the projection reference position.