CAM STRUCTURE FOR LENS BARREL

摘要

PROBLEM TO BE SOLVED: To provide a cam structure for a lens barrel capable of more shortening the length of a cam ring in the axial direction thereby able to furthermore shorten its housing length. SOLUTION: The cam structure for the lens barrel is equipped with an annular member supporting an optical element and guided to straight advance in an optical axis direction and the cam ring having a cam groove with which a cam follower provided in the annular member is engaged on its inner peripheral surface. The cam groove has a photographing area where the annular member is located at a photographing feasible position and a housing area where it is located at a housing position where photographing is not performed. The rear end of the cam groove is opened to the rear end face of the cam ring and an open cam groove area is set as the housing area. The cam structure is provided with a spring means energizing and moving the annular member forward so that the cam follower may be always pressed to the front side cam surface of the cam groove. In the housing area, the cam follower can be separated from the front side cam surface in the open cam groove area against the spring means. COPYRIGHT: (C)2004,JPO&NCIPI