Zoom lens barrel assembly including a clutch mechanism for a camera

摘要

A zoom lens assembly for a zoom lens having at least two lens groups comprises at least one rotatable lens barrel equipped with a first guide cam for shifting one of the two lens group relative to the lens barrel along the optical axis, a rotatable ring member equipped with a second guide cam for shifting the lens barrel along the optical axis and an electromagnetically operated clutch mechanism for locking the rotatable ring member to permit relative rotation of the lens barrel to the ring member so as to shift the lens group according to the first and second guide cams for focusing the zoom lens and unlocking the rotatable ring member from the lens barrel to cause integral rotation of the rotatable ring member and the lens barrel so as to shift the lens group according to the first guide cam only for adjusting a zoom ratio of the zoom lens.