| 摘要 |
PROBLEM TO BE SOLVED: To provide a highly reliable lens barrel which is not provided with a manual switching device and which can always perform manual adjustment other than when a lens is driven by installing a mechanism cutting off a motive power transmitting system when ordinary automatic focusing adjustment is not operated and capable of transmitting the driving of a distance adjusting barrel only when rotational motive power is obtained from a motor. SOLUTION: A driving coupling mechanism part from a motor 12 to a distance adjusting barrel 5 is parted and the connection and disconnection part of an installed clutch is always constituted of a coupling locking member energizing to a release state and a coupling ratchet. A mechanism which cuts off a motive power transmitting system when ordinary automatic focusing adjustment is not operated by performing the coupling and releasing operation of the clutch by the rotation start operation and the rotation operation just before stopping of the motor 12 and can transmit the driving of the barrel 5 only when the rotational motive power is obtained from the motor 12, is installed. Namely, this lens barrel is provided with a clutch mechanism 11 automatically operating between the motor 12 and a clutch pinion 9a, reduction gear trains 9b to 9d and an output pinion 9e. |
