| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a zoom lens barrel whose size can also be reduced without requiring such a condition that the retraction mechanism of a retraction lens frame limits the arrangement of a cam groove for driving forward or backward a mirror frame and the arrangement of a photographing unit. <P>SOLUTION: A zoom lens barrel 1 includes: a fixed frame 2; a cam frame 5 rotationally driven relative to the fixed frame 2 and having a cam groove for driving a retraction lens frame; a second group zoom frame 8 driven by the cam frame 5 so as to move forward or backward and having a retraction cam 8d for driving the retraction lens frame; a third group zoom frame driven by the cam frame 5 so as to move forward or backward; and a retraction lens frame 12, that is, a lens frame supported by the third group zoom frame so as to be rotatable, which holds the retraction lens 3 and is put in an entry position in which the retraction lens 33 is located on an optical path in a photographing state, and which is rotationally driven by the cam groove 5d of the cam frame 5 and the retraction cam 8d of the second group zoom frame 8 during the period of a switching operation from the photographing state to a collapsed state and thereby is driven in a retracted manner to a retracted position P2. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
