| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens for satisfactorily correcting variation of curvature of field due to a projection change over a wide projection range from a close side to an infinite side and having a good optical performance. SOLUTION: The zoom lens includes a plurality of lens units 10-60. The first lens unit 10 is disposed closest to a magnification side in the plurality of lens units and has a negative optical power, and variable-magnification lens units 20-50 that are disposed closer to a reduction side than the first lens unit and moved for changing magnification. The first lens unit includes, in order from the magnification side, a first-A lens sub-unit having a negative optical power and a first-B lens sub-unit having a positive optical power. For focusing from an infinite side to a close side, the first-A and first-B lens sub-units are moved as a distance therebetween is increased, and the first-B lens sub-unit is moved toward the reduction side. COPYRIGHT: (C)2009,JPO&INPIT
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