| 摘要 |
PROBLEM TO BE SOLVED: To provide a linear driving mechanism having an electromechanical transducing element which is not influenced by the elastic deformation of constituents. SOLUTION: In an internal cylinder 17 fixed to a stationary mirror cylinder, a drive shaft 14 arranged in parallel to an optical axis is supported in a freely movable way by the bearings 17p, 17q of extended parts 17a, 17b stretching in the radial direction. Besides, piezoelectric elements 15 are arranged, fixed, and united between the extended part 17a and an acting member 18. The upper half of the acting member 18 touches the drive shaft 14, and to the lower half of the acting member 18, a pad 18c energized by a spring 18b is fitted, and the acting member and the pad are united to the drive shaft by a suitable frictional force. When expansion/contraction displacements of different speeds are generated in the piezoelectric elements. the drive shaft 14 moves through the medium of the acting member 18, and the drive shaft 18 is let out and together with a lens holding frame 13 being a member to be driven. |
