| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens having negative precedence that is advantageous in obtaining a field angle at a wide angle end and reducing the size of the zoom lens, and also is advantageous in obtaining a variable power ratio and optical performance. Ž<P>SOLUTION: The zoom lens includes, in order from the side of an object, a first lens group of negative refractive power, a second lens group of positive refractive power, a third lens group of negative refractive power, and a fourth lens group of positive refractive power, and a brightness diaphragm disposed between the first and third lens groups. For zooming from a wide angle end to a telephoto end, the intervals between the lens groups change such that the first group moves toward an image and then toward the object, the second lens group moves toward the object at the telephoto end rather than at the wide angle end, the interval between the second and third lens groups increases at the telephoto end than that at the wide angle end, and the brightness diaphragm moves toward the object at the telephoto end rather than at the wide angle end. The second and third lens groups satisfy predetermined conditional formula. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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