Patent ID: 6680804
Filing Date: 2004-01-20
Classification: G02B

Abstract:
A zoom lens mechanism for moving a switching lens group of a zoom lens system through at least a first zooming range and a second zooming range, said switching lens group constituting one of a plurality of variable lens groups of said zoom lens system, which moves in an optical axis direction upon zooming, and including first and second sub-lens groups, wherein said first and said second sub-lens groups serves serve as a focusing lens group in a mutually close position and in a mutually distant position in the optical axis direction, said zoom lens mechanism comprising:a switching lens group frame supporting a first sub-lens group frame and a second sub-lens group frame in a manner that allows relative rotation and linear movement in the optical axis direction of said first and second sub-lens groups, said first and second sub-lens group frames supporting said first and said second sub-lens groups, respectively; a lens group shift mechanism for causing said first and second sub-lens group frames to move to said mutually close position and remain in said mutually close position throughout said first zooming range, and to move to said mutually distant position and remain in said mutually distant position throughout said second zooming range, in accordance with relative rotation between said first sub-lens group frame and said second sub-lens group frame; and a focusing mechanism which integrally moves said first sub-lens group frame and said second sub-lens group frame in the optical axis direction while maintaining a distance between said first and said second sub-lens group frames after said first and said second sub-lens group frames are moved to one of said mutually close position and said mutually distant position by said lens group shift mechanism.