Patent ID: 7830612
Filing Date: 2010-11-09
Classification: G02B

Abstract:
1. A zoom lens comprising: a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; a third lens unit having a positive refractive power; a fourth lens unit having a negative refractive power; and a fifth lens unit having a positive refractive power, wherein the first lens unit, the second lens unit, the third lens unit, the fourth lens unit, and the fifth lens unit are arranged in order from the object side to the image side, wherein all of the lens units are moved during zooming from the wide-angle end to the telephoto end such that a distance between the first lens unit and the second lens unit is increased and a distance between the third lens unit and the fifth lens unit is increased, wherein the following condition is satisfied: where f4 is a focal length of the fourth lens unit, f5 is a focal length of the fifth lens unit, fw is a focal length of the entire system of the zoom lens at the wide-angle end, and ft is a focal length of the entire system of the zoom lens at the telephoto end, and wherein the following condition is satisfied; where f2 is a focal length of the second lens unit.