| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a zoom lens whose entire lens system is compact and which has high optical performance over an entire zoom range. <P>SOLUTION: A zoom lens comprises, in order from an object side to an image side, a first lens group with positive refractive power, a second lens group with negative refractive power, a third lens group with positive refractive power, and a fourth lens group with positive refractive power, and each lens group is moved to perform zooming. At a telephoto end, the first lens group and the third lens group are located closer to the object side compared to at a wide angle end. Amounts of movement m1, m2, m3 of the first lens group, the second lens group and the third lens group in an optical axis direction in zooming from the wide angle end to the telephoto end, a focal length f3 of the third lens group, and a focal length ft of the zoom lens at the telephoto end are each set properly. <P>COPYRIGHT: (C)2012,JPO&INPIT |
