| 摘要 |
In order to provide a zoom lens barrel in which the direction of rotation of a zoom ring or a focus ring during the operation thereof can be independently determined even if use is made of a cam cylinder in which the mutual relation between the movement locus of a lens for focusing and the movement locus of a lens for focal length change cannot be destroyed, provision is made of a fixed cylinder, a zoom ring operated during a focal length change, a focus ring operated during focusing, a cam mechanism for moving each of lens units in the direction of the optical axis thereof by the rotational force of the zoom ring without rotating them about the optical axis, and moving the lens units in the direction of the optical axis while rotating them about the optical axis by the rotational force of the zoom ring, an interlocking ring rotatably fitted to the fixed cylinder, and a rotatable gear for transmitting the rotational force of the focus ring while reversing the direction thereof, and the interlocking ring guides the lens units in the direction of the optical axis, while rotating them about the optical axis by the rotational force transmitted from the rotatable gear.
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