| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a zoom lens whose entire system is small, having a high zoom ratio, with satisfactory optical performance across an entire zoom range from a wide angle end to a telephoto end. <P>SOLUTION: A zoom lens comprises, from an object side to an image side in this order: 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 rear group including one or more lens groups. At zooming from a wide angle end to a telephoto end in the zoom lens, an interval between the first lens group and the second lens group increases, an interval between the second lens group and the third lens group decreases, and an interval between the third lens group and the rear group changes. The first lens group comprises, from an object side to an image side in this order: one positive lens; and one negative lens. In the zoom lens, conditional expressions 8.0<f1/fW<30.0 and 2.0<β2T/β2W<10.0 are satisfied, where a focal distance of the first lens group is f1, a focal distance of the entire system at the wide angle end is fW, lateral magnifications of the second lens group at the wide angle end and the telephoto end are β2W, β2T, respectively. <P>COPYRIGHT: (C)2013,JPO&INPIT |
