| 摘要 |
PURPOSE:To simplify lens driving mechanism by varying length by the electrical conduction to a wire made of shape memory alloy, and moving a lens for focus adjustment. CONSTITUTION:A projection piece 13 is provided to the outer circumference of a holding lens frame 9 for a moving lens 7. The piece 13 is fitted in a guide hole 9a provided long in the peripheral wall of the frame 9 in the optical-axis direction. Namely, the pieces 13 moves along the hole 9a and the lens 7 is moved linearly in the optical-axis direction together with the frame 9. Further, another projection piece 14 corresponding to the piece 13 is provided on the external surface of an optical lens barrel 11. The wire 15 made of shape memory alloy such as Ti-Ni alloy or Cu-Zn-Al alloy is extended between the pieces 13 and 14. The work shape of the wire 14 varies in two directions, namely, is long at a high temperature side and long at a low temperature side (e.g. body cavity temperature). |
