Patent ID: 7545579

Claim:
A zoom lens system at least including a first lens group GR 1 having positive refractive power, a second lens group GR 2 having negative refractive power, a third lens group GR 3 having positive refractive power, a fourth lens group GR 4 having positive refractive power, a fifth lens group GR 5 having weak refractive power (including refractive power=0), and a sixth lens group GR 6 having negative refractive power which are arranged in order from the object side, thus to change spacing or spacings between the respective lens groups to thereby perform magnification changing or adjusting operation, wherein when group spacing between the i-th lens group and the j-th lens group at the wide-angle end state is DW(i-j), and group spacing between the i-th lens group and the j-th lens group at the telescopic end state is DT(i-j), the following conditional formulas (1), (2) and (3) are satisfied, DW (1-2)< DT (1-2) (1) DW (2-3)> DT (2-3) (2) DW (5-6)> DT (5-6), and (3) the fourth lens group GR 4 is moved in the optical axis direction so that focusing operation is performed.