Patent ID: 7460310
Filing Date: 2008-12-02
Classification: G02B

Abstract:
1. A zoom lens comprising: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power, wherein the first to third lens units are arranged in that order from an object side toward an image side, wherein the distances between the first to third lens units change during zooming, and wherein the following conditions are satisfied: where fW and fT respectively represent focal lengths of the entire zoom lens at a wide angle end and a telephoto end, f 2 represents the focal length of the second lens unit, β 2 W and β 2 T respectively represent the imaging magnifications of the second lens unit at the wide angle end and the telephoto end, and β 3 W and β 3 T respectively represent the imaging magnifications of the third lens unit at the wide angle end and the telephoto end.