Patent ID: 7885020

Claim:
A lens barrel comprising: a rotational ring driven to rotate about an axis extending in an optical axis direction; a first movable member and a second movable member which are linearly movable in said optical axis direction and have a first follower and a second follower, respectively; and a first guide groove and a second guide groove, formed on a common peripheral surface of said rotational ring, said first follower and said second follower being slidably engaged in said first guide groove and said second guide groove, respectively, wherein a moving path of said first movable member is a non-linear moving path that provides a non-linear relationship between a rotation angle of said rotational ring and a moving amount of said first movable member, wherein said first guide groove includes a linear lead groove which is inclined with respect to a circumferential direction of said rotational ring at a predetermined angle of inclination, wherein said lens barrel includes a complementary cam mechanism for controlling a position of said rotational ring in said optical axis direction so as to define said moving path of said first movable member as said non-linear moving path by a combination of a cam track of said complementary cam mechanism and a track of said linear lead groove of said first guide groove, and wherein said second guide groove includes a first lead groove portion and a second lead groove portion which extend parallel to said linear lead groove of said first guide groove and are located at different positions in said optical axis direction, and a differential groove portion which extends in said circumferential direction and via which said first lead groove portion and said second lead groove portion are connected.