| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens, having a high zoom ratio though lens configuration is simple and compact and attaining high optical performance over the entire zoom region. SOLUTION: The zoom lens includes, in the order starting from an object side to an image side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power and a fourth lens group having positive refractive power; the interval between the first lens group and the second lens group is minimum on the way of zooming; the first lens group is positioned closer to the object side at the telephoto end than at the wide-angle end; the respective lens groups are moved so that the interval between the second lens group and the third lens group is smaller at the telephoto end than at the wide-angle end and the interval between the third lens group; the fourth lens group is larger at the telephoto end than at the wide-angle end; the second lens group comprises a negative lens and a positive lens, in the order starting from the object side to the image side; and the interval d1w between the first lens group and the second lens group at the wide-angle end, the interval d1t between the first lens group and the second lens group at the telephoto end, and the minimum value d1min of the interval between the first lens group and the second lens group, on the way of zooming are respectively set appropriately. COPYRIGHT: (C)2009,JPO&INPIT
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