| 主权项 |
1. A lens barrel that changes image pickup magnification by a lens moving in an optical axis direction of the lens barrel between a stored position and an image pickup position, the lens barrel comprising:
a fixed barrel having a plurality of first projection or follower portions on an outer peripheral part thereof and having a flange portion on an object side-outer peripheral end thereof; a stopper member fixedly arranged coaxially with the fixed barrel and having a plurality of second projection or follower portions, each of which having flank surfaces at both ends thereof in the optical axis direction; and a cam barrel disposed on an outer peripheral side of the fixed barrel and the stopper member, having a plurality of first cam grooves with which the plurality of the first projection or follower portions are cam-engaged, respectively, on an inner peripheral part thereof, and having a plurality of second cam grooves, with which the plurality of the second projection or follower portions are engaged, respectively, on the inner peripheral part thereof, at a position toward an image surface side away from the first cam grooves in the optical axis direction, the plurality of second cam grooves having the same locus as that of the plurality of first cam grooves and rotatingly moving in the optical axis direction relative to the fixed barrel and the stopper member due to the engagement between the first projection or follower portions and the first cam grooves and the engagement between the second projection or follower portions and the second cam grooves, wherein in an area where the cam barrel is extended to the object side and is close to the flange portion of the fixed barrel, side walls of the plurality of the second cam grooves with which the plurality of the second projection or follower portions are engaged, respectively, are open on the image surface side of the plurality of the second cam grooves. |
