Zoom lens barrel

摘要

A lens barrel for a zoom lens includes first and second lens groups arranged in the direction of an optical axis. A first rotary barrel is rotatable about the optical axis and is rotated to move the first lens group in the direction of the optical axis, and a second rotary barrel is provided coaxially with the first rotary barrel. A guide groove is provided on the second rotary barrel and guides the second lens group to move it in the direction of the optical axis in response to rotation of the second rotary barrel. A rotation transmission mechanism is disposed between the first and second rotary barrels to be able to engage to rotate both the first and second rotary barrels, thereby zooming the zoom lens, and to be able to disengage to rotate only one of the first and second rotary barrels through a predetermined angle range with the other held stationary so that focusing the zoom lens can be effected by rotating said one rotary barrel within the predetermined angle range.