Patent ID: 8437090

Claim:
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, second, third, fourth, and fifth lens units are arranged in order from an object side to an image side, wherein a distance between the first lens unit and the second lens unit is longer at a telephoto end than at a wide angle end, a distance between the second lens unit and the third lens unit is shorter at the telephoto end than at the wide angle end, a distance between the third lens unit and the fourth lens unit differs between the telephoto end and the wide angle end, and a distance between the fourth lens unit and the fifth lens unit is longer at the telephoto end than at the wide angle end, and wherein the following conditional expressions are satisfied: 4.0< f 1 /fw< 15.0 −1.00 <M 1/ TDw<− 0.46 2.0<| f 4|/ fw< 6.0 where f 1 and f 4 represent focal lengths of the first lens unit and the fourth lens unit, fw represents a focal length of the entire zoom lens at the wide angle end, M 1 represents a moving amount of the first lens unit during zooming from the wide angle end to the telephoto end, a sign of the moving amount M 1 is positive when the first lens unit moves to the image side, and TDw represents a distance from a lens surface closest to the object side in the first lens unit to an image plane at the wide angle end, wherein the moving amount M 1 of the first lens unit during zooming from the wide angle end to the telephoto end corresponds to a difference between a total length of the zoom lens at the wide angle end and a total length of the zoom lens at the telephoto end.