| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable magnification lens which is short in the overall lens length at a wide angle end while assuring a space to accommodate an optical filter. SOLUTION: The variable magnification lens is arranged successively from an object side with a first lens group L1 having negative refracting power, a second lens group L2 having positive refracting power, and a third lens group L3 having positive refracting power, wherein at least one face of the at least one lens in each of the first lens group L1, the second lens group L2, and the third lens group L3 is formed as an aspheric surface. The configuration that the overall length LW of the lenses at the wide angle end, defined as Lw, and the focal length of the entire system of the lenses at the wide angle end, defined as fw, have a relation 2<Lw/fw<3.5 and that the at least two lens groups among the three lens groups are moved in the optical axis direction is employed. COPYRIGHT: (C)2005,JPO&NCIPI
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