Patent ID: 6754011
Filing Date: 2004-06-22
Classification: G02B

Abstract:
A high zoom ratio lens, comprisingfour groups of lenses, a fixed barrel, a first cam barrel disposed inside the fixed barrel, a linear barrel disposed inside the first cam barrel, a focusing cam disposed inside the linear barrel, and a second cam barrel disposed outside the fixed barrel and rotatably connected to the first cam barrel; first one of the groups of lenses being moved for zooming by means of a first cam provided in the second cam barrel; second one of the groups of lenses serving as a focusing lens and being moved for zooming by means of a secondâ€”A cam provided in the linear barrel; at least either third or fourth one of the groups of lenses being moved for zooming by means of a cam provided in the first cam barrel; and the second group of lenses being moved for focusing by means of a secondâ€”B cam provided in the focusing cam.