Patent ID: 8743475

Claim:
A lens barrel, comprising: a fixed cylinder; a lens holding frame which holds a lens; a cam ring mounted on the fixed cylinder in such a manner as to be engaged with the lens holding frame and to be rotatable about an optical axis, the cam ring comprising a cam groove; a first projection which is formed on one of the fixed cylinder and the cam ring; a first rotation restricting portion which is formed on the other of the fixed cylinder and the cam ring; a second projection which is formed on one of the fixed cylinder and the cam ring; and a second rotation restricting portion which is formed on the other of the fixed cylinder and the cam ring, wherein the lens holding frame has an engaging member movable along the cam groove in engagement therein; the cam ring moves the lens holding frame in a direction of the optical axis as the cam ring is rotated about the optical axis, the first rotation restricting portion is contacted with the first projection when the cam ring is rotated in a first direction for restricting the rotation of the cam ring in the first direction, and the second rotation restricting portion is contacted with the second projection when the cam ring is rotated in a second direction opposite to the first direction for restricting the rotation of the cam ring in the second direction.