Zoom lens barrel employing a drive cam for moving lens groups

摘要

A zoom lens barrel that performs zooming by moving a plurality of lens groups, which constitute a photo-taking optical system, by interlocking the lens groups with each other. The zoom lens barrel includes a first frame supporting a first lens group, and a second frame supporting a second lens. A cam tube supports both the first frame and the second so that the frames can relatively move in the direction of the optical axis of the optical system. A drive cam is provided in the cam tube and has a cam that has a first cam region for moving the first frame in the direction of the optical axis and a second cam region for moving the second frame in the direction of the optical axis. The drive cam is formed so that the first and the second frame may commonly use partial regions of the first cam region and the second cam region at the time of performing the zooming.