Patent ID: 8456753

Claim:
A lens barrel comprising: a rectilinear guide cylinder configured to rectilinearly move in an optical axis direction of the lens barrel, said rectilinear guide cylinder having a first cam groove formed on an inner peripheral surface thereof, a second cam groove formed on the inner peripheral surface thereof, and a rectilinear guide groove extending in the optical axis direction and dividing the first cam groove at a boundary region between a retracted region and a photographing region; and a movable cam cylinder configured to move in the optical axis direction while rotating relative to said rectilinear guide cylinder, said movable cam cylinder having a first pin that engages the first cam groove and a second pin that engages the second cam groove, wherein the first cam groove in the retracted region is larger in width than the first pin, and the first cam groove in the retracted region is larger in width than the first cam groove in the photographing region, whereas the second cam groove in the photographing region is larger in width than the second pin, and the second cam groove in the photographing region is larger in width than the second cam groove in the retracted region, and wherein said movable cam cylinder moves in the photographing region while the first pin engages the first cam groove, and moves in the retracted region while the second pin engages the second cam groove.