Patent ID: 7580201

Claim:
A zoom lens system, comprising, in order from an object side to an image side: a first lens group having positive refractive power; a second lens group having negative refractive power, the second lens group comprising a first aspheric lens; a movable stop; a third lens group having positive refractive power, the third lens group comprising a hybrid lens; and a fourth lens group having positive refractive power, the fourth lens group comprising a second aspheric lens; wherein the first and fourth lens groups are stationary and the second and third lens groups are movable relative to the first and fourth lens groups for varying the focal length, and wherein the second lens group and the third lens group satisfy the following condition: 0.55 <  F ⁢ ⁢ 2 F ⁢ ⁢ 3  < 1.2 where F 2 represents the focal length of the second lens group, and F 3 represents the focal length of the third lens group.