Patent ID: 8531776

Claim:
A zoom lens system, in the order from the object-side to the image-side thereof, comprising: a first lens group with negative refraction power, the first lens group comprising a first lens and a second lens; a second lens group with positive refraction power, the second lens group comprising a third lens, a fourth lens, and a fifth lens, the fourth lens and the fifth lens are attached together; and a third lens group with positive refraction power, the third lens group comprising a sixth lens; wherein the zoom lens system satisfies the following conditions: 0.35 <f 2 /f 3<0.7; 1.8<| f 45/ Fw|< 3; 0.5<| f 1|/ Ft< 0.9; 0.7< f 3/ Ft< 1.2; 0.6 <M 2 /Ft< 0.7; 3.3<( N 1+ N 2)<3.56; 16<( V 1− V 2)<28; wherein, f 1 is a focal length of the first lens group; f 2 is a focal length of the second lens group; f 3 is a focal length of the third lens group; f 45 is a focal length of the attached fourth lens and fifth lens; Fw is a focal length of the zoom lens system in a wide angle state; Ft is a focal length of the zoom lens system in a telephoto state, M 2 is the longest moving distance of the second lens group from the wide angle state to the telephoto state; N 1 is the refractive index of the first lens; N 2 is the refractive index of the second lens; V 1 is the Abbe number of the first lens; V 2 is the Abbe number of the second lens.