| 摘要 |
PROBLEM TO BE SOLVED: To achieve a high field angle of 38 degrees or more of a half field angle by thinning thickness of an optical axis direction of an imaging device such as a camera and excellently correcting a chromatic aberration of magnification being a problem in high variable power zoom lens of 10 times or more. SOLUTION: The zoom lens includes five lens groups G1, G2, G3, G4, G5 of positive, negative, positive, negative and positive lens groups. The second lens group G2 is composed as a so-called "variator" bearing main variable power action. The second lens group G2 secures a degree of freedom of correction "aberration correction having difficulty accompanying high variable power" by bearing one's share of variable power action in even lens groups on and behind a third lens group G3 to relieve the burden of the second lens group G2. A fifth lens group G5 serves as a so-called "compensator" for correcting image face position variation accompanying variable power. A fourth lens group G4 has a focusing function due to movement of an object point. COPYRIGHT: (C)2010,JPO&INPIT
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