| 摘要 |
PROBLEM TO BE SOLVED: To realize the smooth movement of an optical lens part from the outside of moving tolerance to the moving tolerance in focusing. SOLUTION: The focusing device 1 is equipped with a driven and rotated lead screw 5, a nut 35 and the optical lens part 3, and performs focus adjusting by moving the lens part 3 in an optical axis direction by the movement of the nut 35. In the device 1, a gap Ga is formed between the screw 5 and the nut 35 at the edge part 13 of the screw 5. Since backlash occurs at the edge part 13 of the screw 5 by the gap Ga, frictional resistance and clamping torque between the screw 5 and the nut 35 are reduced and the biting of the screw 5 and the nut 35 is softened. Therefore, in the case of moving the lens part 3 from the edge part 13 of the screw 5 to the middle part 16 thereof, the lens part 3 is restored to the middle part 16 in a state where the nut 35 is screwed on the screw 5. COPYRIGHT: (C)2004,JPO&NCIPI |
