| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens barrel where a plurality of lens frames are smoothly driven with simpler constitution by restraining the complication of a driving mechanism part for moving two lens frames, also stable optical performance is secured and the sure driving control of a plurality of lens frames is secured. SOLUTION: This zoom lens barrel having at least 1st and 2nd lens groups 21 and 22 moving in the optical axis direction is equipped with a cam ring 4 having a 1st guiding means 4b guiding the 1st lens group in the optical axis direction, and a 2nd guiding means 4c constituted of a plurality of focusing sections where the 2nd lens group is driven or retained in the optical axis direction for the purpose of focusing operation and a plurality of variable power sections which are provided to succeed to the plurality of focusing sections respectively and arranged alternately with the plurality of focusing sections and where the 2nd lens group is driven in the optical axis direction for the purpose of variable power operation. The 1st guiding means is formed to linearly drive the 1st lens group with respect to the turning of the cam ring at least at the time of variable power operation, and the plurality of variable power sections are set to have a plurality of section lengths.
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