Patent ID: 7215483

Claim:
A zoom lens system comprising: a first lens unit having negative optical power; a second lens unit having positive optical power, the second lens unit including a first lens subunit and a second lens subunit, the first lens subunit consisting of a first positive lens element and a negative lens element, the first positive lens element and the negative lens element being disposed in this order from an object side to an image side, the second lens subunit including at least one second positive lens element, the first lens subunit and the second lens subunit being disposed in this order from the object side to the image side; and a third lens unit having positive optical power, wherein the first lens unit, the second lens unit, and the third lens unit are disposed in this order from the object side to the image side, wherein a distance between the first lens unit and the second lens unit and a distance between the second lens unit and the third lens unit are changed during zooming, and wherein the following conditions are satisfied: 1.0 <|f 1|/( f 2·tan ω w )<1.6 1.6 <f 2/ fw< 2.6 where ωw is half of the angle of view of the zoom lens system at a wide-angle end, f 1 is the focal length of the first lens unit, f 2 is the focal length of the second lens unit, and fw is the focal length of the entire zoom lens system at the wide-angle end.