| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and inexpensive lens barrel capable of preventing a forefront lens group from being rotated even in the case of a high-power zoom lens. SOLUTION: By providing a cam for driving respective lens groups (LB1 to LB4) dividedly to a 1st cam ring 120 and a 2nd cam ring 106, a connection part required in the conventional manner is eliminated and the lens barrel is miniaturized in a radial direction. The 1st lens group LB1 moves straight without rotation by regulating the rotation of a guide barrel 131 by a 3rd group lens moving frame 103 so that the guide barrel 131 is guided to straight advance and driving it in a back-and-forth direction by the cam ring 120. Furthermore, since a projection 101e and the positioning hole 131d of the guide barrel 131 are arranged so that a 1st group lens chamber 101 can be attached even when it is rotated by 180 deg. with respect to the guide barrel 131, the 1st lens group LB1 can be easily attached by being rotated by 180 deg. in order to adjust the optical performance of the lens barrel 100B.
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