| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens barrel which enables macrophotography without extending and forming a 2nd cam area formed on a cam ring. SOLUTION: The zoom lens barrel 1 is equipped with a photography optical system 2 having a plurality of photographic lenses 11 and 12 which can independently be moved along the optical axis respectively and an operating mechanism 3 which independently move the respective photographic lenses along the optical axis. The operating mechanism is equipped with a fixed cylinder 21 for moving the respective photographic lenses only along the optical axis, the cam ring 31 which is supported rotatably by the fixed cylinder and has a plurality of cam grooves supporting the respective photographic lenses rotatably, and a driving means 51 of imparting a rotational driving force to the cam ring, and the cam ring comprises a plurality of cam ring pieces 32 and 33 which are coupled together through a coupling elastic body 34, the optical-axis-directional position relation between the photographic lenses supported by the respective cam ring pieces are set to relation different from the track determined by the cam ring pieces. COPYRIGHT: (C)2004,JPO
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