| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lens barrel which is a collapsible lens barrel, can be further miniaturized in a storage state and prevents the inside of the lens barrel from being damaged due to falling etc. <P>SOLUTION: The lens barrel includes a first frame, a second frame which is rotatably supported by the first frame and can be extended and retracted relative to the first frame, a drive actuator rotationally driving the second frame relative to the first frame, and a transmission mechanism transmitting the drive force of the drive actuator. The second frame includes a cylindrical main body part, a gear part to which a rotational drive force is transmitted by the transmission mechanism disposed in the inner circumferential surface of the main body part, and a cam groove having an inflection part in a range where the variable power ratio of an optical system is changed. The transmission mechanism includes a first transmission gear part engaged with a gear, a second transmission gear part coaxially provided with the first transmission gear part, and a clutch between the first transmission gear part and the second transmission gear part. The clutch temporarily releases the drive force of the drive actuator transmitted to the first transmission gear part, only for a unidirectional rotation. <P>COPYRIGHT: (C)2013,JPO&INPIT |
