Abstract: The invention relates to a lens mount assembly used for various kinds of optical apparatus such as photographic camera, motion picture handy camera and video camera, characterized in that the stationary sleeve which has usually been employed to support the cam sleeve and the movable sleeve is eliminated. To this end, the movable sleeve is formed with a plurality of keying grooves and there is provided a supporting framework comprising a plurality of keying levers adapted to be slidably engaged into the respective keying grooves. The cam sleeve is rotatably mounted around the movable sleeve so that the movable sleeve is operatively associated with the cam sleeve and guided by the keying levers to be moved in the direction of the optical axis.

Abstract: A zoom lens mount assembly in which a zooming cam frame is moved along the optical axis while rotating therearound and respective movable frames supporting an optical system are driven by such rotation and movement of the cam frame to effect a desired zooming. In another aspect there is provided a focussing cam frame adapted to be moved along the optical axis and to drive a movable frame provided with a focussing optical system and a program lens shutter.