Lead screw device, lens driver, lens barrel, and camera using the lead screw device

Abstract

An optical device includes an optical system including a plurality of lens groups, at least one lens group being a movable lens group moving in an optical axis direction, and a movable frame to move the movable lens group. The movable frame includes a driving source, a drive screw, a lens supporting frame, and maintaining an integrated state relative to the movable lens group, a plurality of arms disposed in a position to face the drive screw and being openable and closable relative to the drive screw with a single opening and closing axis as a support axis, the plurality of arms including a first arm and a second arm, and a biasing spring configured to apply a biasing force to the first arm in a direction in which the first arm approaches the drive screw, wherein the lens supporting frame is further configured to support the biasing spring.

What is claimed is: 
     
         1 . An optical device comprising:
 an optical system including a plurality of lens groups, at least one lens group of the plurality of lens groups being a movable lens group capable of moving in an optical axis direction of the optical system; and   a movable frame configured to move the movable lens group,   the movable frame including:
 a driving source; 
 a drive screw driven by the driving source; 
 a lens supporting frame configured to support the movable lens group and maintaining an integrated state relative to the movable lens group; 
 a plurality of arms disposed in a position to face the drive screw and being openable and closable relative to the drive screw with a single opening and closing axis as a support axis, the plurality of arms including a first arm and a second arm; and 
 a first biasing spring configured to apply a first biasing force to the first arm in a direction in which the first arm approaches the drive screw, wherein the lens supporting frame is further configured to support the first biasing spring.