| 摘要 |
PURPOSE: To achieve both of quick operation and fine focusing. CONSTITUTION: A main body 21 is provided with an operation ring for coarse adjustment 45 and an operation ring for fine adjustment 49. The rotation of the ring 49 is directly transmitted to a main gear 38 coupled to a potentiometer 22 and the rotation of the rings 45 is transmitted to the gear 38 through an idle gear 34 and an idle gear 35. Then, since the rotation ratio of the ring 45 and the ring 49 are different from each other, both of coarse adjustment and fine adjustment are executed by rotating either of them. Besides, a C-shaped thrust groove 25c is formed on a rotation ring 25. By engaging a stopper shaft 29 fixed to the main body 21 with the groove 25c, the rotation of the ring 25 is stopped and a mechanical terminating end can be constituted when a photographing lens arrives at a shortest distance or infinity. |
