| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens having high performance, also, having a wide angle of view, made sufficiently compact, and having a high zooming ratio. SOLUTION: The zoom lens is constituted by successively arranging a positive first group optical system G1, a negative second group optical system G2, a positive third group optical system G3, a negative fourth group optical system G4 and a positive fifth group optical system G5 from an object side. In zooming from a short focal end to a long focal end, an interval between the first group optical system G1 and the second group optical system G2 increases, an interval between the second group optical system G2 and a diaphragm FA decreases, an interval between the diaphragm FA and the third group optical system G3 decreases, an interval between the third group optical system G3 and the fourth group optical system G4 increases, and an interval between the fourth group optical system G4 and the fifth group optical system G5 varies. Provided that an interval between the second group optical system G2 and the third group optical system G3 at a short focal end is expressed as T23w, the maximum image height is expressed as Y', a focal length at a long focal end is expressed as ft, and a focal length at a short focal end is expressed as fw, the zoom lens satisfies 0.5<(T23w/Y')/(ft/fw)<1.0. COPYRIGHT: (C)2009,JPO&INPIT
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