| 摘要 |
PROBLEM TO BE SOLVED: To eliminate the need of switching operation between manual and automatic operation and to prevent operation torque from being changed according to the kind of a lens and other conditions. SOLUTION: The movable plate 26 of a clutch mechanism is connected to the external tooth of a zoom operation ring and the fixed plate 27 of the clutch mechanism is coupled with a zoom motor 35. Then, the movable plate 26 is actuated by a clutch actuation motor 37, so that the fixed plate 27 is engaged with and released from the fixed plate 27. This clutch mechanism automatically performs switching between manual and electrical operation based on the operation of a zoom switching 20, and the operation torque of the lens operation ring is applied by frictional force at the time of manual operation. The operation torque is set to a specified value by a slip torque setting circuit 54, and the manual operation torque is controlled and maintained to be constant based on the torque value detected by a detection circuit 52 and the set value of the circuit 54 by a comparator circuit 55. |
