Patent ID: 7706081

Claim:
A zoom lens system, from an object side to an image side on an optical axis comprising: a first lens group with positive optical power consisted of two lenses without binding together and having a predetermined distance therebetween; a second lens group with negative optical power; a third lens group with positive optical power comprising, in order from the object side to the image side, a fifth biconvex lens and a sixth biconcave lens, wherein the fifth biconvex lens is adhering to the sixth biconcave lens; a fourth lens group with positive optical power; and an aperture stop arranged between the second lens group and the third lens group; wherein when the zoom lens system is zooming from wide status to telephoto status, the second lens group is moved toward the image side and the third lens group is moved toward the object side, the positions of the first lens group and the aperture stop on the optical axis are fixed; wherein the zoom lens system satisfies the following condition: Y × L 2 × f W × f T ≤ 1.06 wherein Y is a maximum diagonal length of the image side, L is a total track length of the zoom lens system, f W is a focal length of the zoom lens system at a wide status, f T is a focal length of the zoom lens system at a telephoto status.