| 摘要 |
PROBLEM TO BE SOLVED: To obtain a zoom lens which is compact and is easily manufactured though it has a high variable power ratio. SOLUTION: The zoom lens has a 1st lens group L1 having positive refractive power, a 2nd lens group L2 having negative refractive power, a 3rd lens group L3 having positive refractive power, and a 4th lens group L4 having negative refractive power in order from an object side to an image side. In zooming from a wide angle end to a telephoto end, the 1st to the 4th lens groups L1 to L4 respectively move on an optical axis to the object side. The respective lens groups respectively comprise two or less lenses, and the 3rd lens group L3 includes an aspherical lens G31 composed of resin material. Assuming that the focal distance of the lens G31 is fp, the focal distance of the 4th lens group L4 is f4 and the focal distance of an entire system at the wide angle end is fw, the zoom lens satisfies a condition 2.0<¾fp¾/fw, 0.35<¾f4¾/fw<0.75. COPYRIGHT: (C)2006,JPO&NCIPI
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