| 摘要 |
PROBLEM TO BE SOLVED: To obtain a zoom lens realizing the miniaturization of an entire lens system and having high optical performance in spite of simple constitution, and an imaging device having the zoom lens. SOLUTION: The zoom lens has a 1st lens group L1 having positive refractive power, which is fixed on an optical axis for zooming, a 2nd lens group L2 having negative refractive power, which moves on the optical axis for zooming, a 3rd lens group L3 having positive refractive power, whose space with the 1st lens group L1 is constant in the case of zooming, and a 4th lens group L4 having positive refractive power, which moves on the optical axis in the case of zooming in order from an object side to an image side. The 1st lens group L1 is constituted of one positive lens, and the 3rd lens group L3 has one or more negative lenses and one or more positive lenses, then the 4th lens group is constituted of one positive lens. COPYRIGHT: (C)2005,JPO&NCIPI
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