Patent ID: 7312930
Filing Date: 2007-12-25
Classification: G02B

Abstract:
1. A zoom lens comprising: a first lens unit having a negative refractive power, and including a first lens having a negative refractive power; a second lens unit having a positive refractive power, and including a first lens having a positive refractive power and a second lens having a negative refractive power; and a third lens unit having a positive refractive power, and including a first having a positive refractive power, wherein the first, second, and third lens units are arranged in that order from an object side to an image plane side of the zoom lens, and wherein the first lens unit is fixed and the second lens unit and the third lens unit are movable during zooming from a wide-angle end to a telephoto end, and wherein the following conditions (1) and (2) are satisfied: where Dw 1 - 2 represents the distance between the first lens unit and the second lens unit at the wide-angle end, Dw 2 - 3 represents the distance between the second lens unit and the third lens unit at the wide-angle end, Dt 1 - 2 represents the distance between the first lens unit and the second lens unit at the telephoto end, and Dt 2 - 3 represents the distance between the second lens unit and the third lens unit at the telephoto end.