Patent ID: 7408722
Filing Date: 2008-08-05
Classification: G02B

Abstract:
1. A cam mechanism of a zoom lens, comprising: a cam ring including a plurality of cam grooves having different reference cam diagrams, said cam grooves being formed on at least one of inner and outer peripheral surfaces of said cam ring; and a plurality of movable frames which include a plurality of cam followers respectively engaged in said plurality of cam grooves, said movable frames being guided linearly in an optical axis direction, wherein each of said plurality of cam grooves includes a zooming section for moving an associated one of said plurality of movable frames between a wide-angle extremity position and a telephoto extremity position in said optical axis direction in accordance with rotation of said cam ring, and a zooming-range-extremity stop section, communicatively connected to one end of said zooming section, for preventing said associated one of said movable frames from moving in said optical axis direction from one of said wide-angle extremity position and said telephoto extremity position when said cam ring rotates within said zooming-range-extremity stop section, wherein said zooming-range-extremity stop section is configured to move said each of said movable frames by an amount of movement which offsets an amount of movement of said cam ring in said optical axis direction.