Patent ID: 7400455

Claim:
A zoom lens system consisting, in order from a display medium side, of a first lens group that has negative refractive power and a second lens group that has positive refractive power, the first lens group and the second lens group respectively including at least one aspherical surface, wherein an air distance dw between the first lens group and the second lens group at the wide angle end, an air distance dt between the first lens group and the second lens group at the telephoto end, a combined focal length f 1 of the first lens group, a combined focal length f 2 of the second lens group, and the combined focal length fw of the zoom lens system at the wide angle end satisfy the following conditions 0.05 <dt/dw< 0.17 dt< 2.5 1.3 <|f 1 /fw|< 1.6 1.1 <|f 2 /f 1|<1.4.