Zoom mechanism with cams and levers.

摘要

An optical zoom system including first and second lens groups disposed for relative movement along an optical axis. They are coupled together by a cam and follower mechanism with two pivotally coupled linkages for controlling such relative movement to change the focal length of the optical system. The system is characterized by a mechanism for offsetting relative movement between the lens groups along the optical axis caused by lateral movement of said lens groups essentially normal to said axis, thereby to maintain the focal length constant in the presence of said lateral movement. <IMAGE>