| 摘要 |
PROBLEM TO BE SOLVED: To obtain a compact zoom lens having a high zoom ratio, having a front lens whose effective diameter is small, and also, capable of obtaining high optical performance in the entire zoom range. SOLUTION: The zoom lens includes, in order 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; a fourth lens group having negative refractive power; and a fifth lens group having positive refractive power, wherein the respective lens groups move so that, at a telephoto end with respect to a wide-angle end, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group varies, and a distance between the fourth lens group and the fifth lens group increases. A focal length f2 of the second lens group, a focal length fw of the entire system at the wide-angle end, a moving amount M4 of the fourth lens group during zooming from the wide-angle end to the telephoto end, and the distances D34w and D34t between the third lens group and the fourth lens group at the wide-angle end and at the telephoto end are respectively and appropriately set. COPYRIGHT: (C)2011,JPO&INPIT |
