| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem that it is difficult that a dividing position is accurately set and beside high drive torque is needed, and precision is lowered as a result of a bending moment being exercised to a bearing. SOLUTION: A disc 2 rotatable around a central axis is provided and suited for holding of an object like a lens. The disc 2 is provided with a detent 8 and worked in cooperation with a lock claw 14 situated on a fixing surface adjacent to the disc 2. When the disc is rotated in a first direction, the lock claw 4 is deflected when it passes respective detent 8 and when the detent 8 passes, it is returned to its rest position. When the disc 2 is rotated in a reverse direction, the lock claw 14 makes contact with the detent 8 so as to specify a dividing position. The disc 2 is driven or energized in this direction so as to maintain the position. A stopper 10 can be situated at the disc 2 in adjacent with each detent 8 to specify the position of the lock claw 14 based on the disc 2. The disc 2 can be driven by a motor 12 and a drive means. |
