| 摘要 |
PROBLEM TO BE SOLVED: To provide a lens barrel, ensuring long movement of a lens group, even if using an annular actuator and attaining a zoom lens having a high zoom ratio. SOLUTION: The lens barrel includes a plurality of lens groups movable in the optical axis direction; a driving section having an annular actuator taking the optical axis as the center of rotation; a cylindrical base portion disposed inside the annular actuator and driving at least one lens group among the plurality of lens groups by rotation, a first cam cylinder having a large-diameter portion having a larger outside diameter than that, the large-diameter portion being positioned in an area in the optical axis direction different from the annular actuator; a second cam cylinder for driving at least one lens group by rotation at an outer peripheral side of the large-diameter portion; and a rotation transmitting portion provided at the large-diameter portion for transmitting the rotation of the first cam cylinder to the second cam cylinder. In a state where the length of the lens barrel is shortest, the rotation transmitting portion and a section of the second cam cylinder overlap in the optical axis direction a lens group holding the frame closest to the object side. COPYRIGHT: (C)2011,JPO&INPIT |
