ZOOM LENS BARREL, OPTICAL DEVICE, CAMERA AND METHOD FOR ASSEMBLING ZOOM LENS BARREL

摘要

PURPOSE: To maintain sufficient strength and to prevent faulty actuation without spoiling assembling workability by extending the leading edge of at least one cam groove on a camera front side and allowing it to communicate with a falling-off preventing groove provided in a peripheral direction on the inner surface of a cam ring. ;CONSTITUTION: On the inner surface of the cam ring 3, a 1st group cam groove 3c and a 2nd group cam groove 3d, and the falling-off preventing groove 3b are equally provided by three in an optical axis direction, and in the peripheral direction at the leading edge on the camera front side, respectively. A projection 6a formed at the leading edge of a straight advance guide ring 6 assembled in the cam ring 3 3 is inserted in the 1st group cam groove 3c from a trailing aperture part, and passes a collapsible position and a wide position as the guide ring 6 enters the cam ring 3, and gets in and is fitted in the groove 3b from a communication part formed by extending the edge of a telephoto position. Thus, the cam ring 3 is freely turned around an optical axis with reference to the guide ring 6 but integrally moved in the optical axis direction.;COPYRIGHT: (C)1996,JPO