Patent ID: 7777951

Claim:
A zoom lens comprising, in order from an object side to an image side: a first lens unit having positive refractive power; a second lens unit having negative refractive power; a third lens unit having positive refractive power; and a fourth lens unit having positive refractive power, wherein the fourth lens unit consists of a single positive lens element, wherein the zoom lens performs zooming by moving each of the lens units; the first lens unit and the third lens unit are positioned closer to the object at a telephoto end than at a wide-angle end; and the zoom lens satisfies the following conditions: 0.3<| m 1 /m 2|<1.5 0.3<| m 3 /m 2|<0.8 where m1, m2, and m3 are the amounts of movement of the first lens unit, the second lens unit, and the third lens unit, respectively, along an optical axis during zooming from the wide-angle end to the telephoto end.