Patent ID: 7508594

Claim:
A wide-angle zoom lens system comprising a negativefirst lens group, a positive second lens group, a negative third lens group and a positivefourth lens group, in this order from an object; wherein upon zooming from the short focal length extremity to the long focallength extremity, a distance between said negative first lens group and said positive second lens group decreases, a distance between said positive second lens group and saidnegative third lens group increases, and a distance between said negative third lens group and said positive fourth lens group decreases; and wherein said wide-angle zoom lens system satisfies the following conditions: 1.6< X 2/ fw< 3.5 1.2<| f 1|/ fw< 2.0 ( f 1<0) 1.6< f 2/ fw< 2.7 0.9 <X 2 /f 2<1.6 wherein X 2 designates the traveling distance of said positive second lens group uponzooming from the short focal length extremity to the long focal length extremity; f 1 designates the focal length of said negative first lens group; f 2 designates the focal length of said positive second lens group; and fw designates the focal length of the entire wide-angle zoom lens system at theshort focal length extremity.