Patent ID: 6839187
Filing Date: 2005-01-04
Classification: G02B

Abstract:
1. A lens distance-varying mechanism for varying a distance between a first lens group and a second lens group, said lens distance-varying mechanism comprising: a first lens frame which holds said first lens group; a second lens frame which holds said second lens group, said second lens frame being rotatable relative to said first lens frame within a predetermined angle of rotation; a relative-moving mechanism for moving said first lens frame and said second lens frame to change a relative position therebetween on an optical axis when said second lens frame is positioned at each of forward and reverse rotation extremities of said second lens frame relative to said first lens frame; a differential linking ring which rotates together with said second lens frame; a differential ring which is rotated relative to said differential linking ring by a first angle of rotation greater than a second angle of rotation of said second lens frame relative to said first lens frame; and a biasing member, positioned between said differential ring and said differential linking ring, for absorbing a difference between said first angle of rotation and said second angle of rotation.