Patent ID: 7339751

Claim:
A lens barrel comprising: a straight-moving cylinder including therein a lens group located on an anterior portion thereof, being movable in a direction of an optical axis of the lens group without being rotated, and having a depression on a posterior end portion of the straight-moving cylinder; at least one guide pin located on an outer circumferential surface of the straight-moving cylinder, while protruding from the outer circumferential surface of the straight-moving cylinder; a rotational-moving cylinder located around an outer circumference of the straight-moving cylinder, being movable in the direction of the optical axis, having a cam groove located in an inner circumferential surface thereof for engaging with the at least one guide pin, and configured for moving in the direction of the optical axis under rotation; and a reinforcement pin projecting from the inner circumferential surface of the rotational-moving cylinder, wherein the depression includes a contact surface separated from a side portion of the reinforcement pin with a predetermined clearance, said contact surface varying in distance from the posterior end portion of the straight moving cylinder such that the predetermined clearance between the contact surface and the reinforcement pin is maintained when the reinforcement pin moves with respect to the contact surface as the lens barrel moves between stored and wide states.