Patent ID: 7551365

Claim:
A zoom lens, consisting essentially of: a first lens group which has a fixed distance from an image plane and which has negative refracting power; a second lens group which has positive refracting power and which moves at a time of zooming; a third lens group which has positive refracting power and which moves at a time of zooming; and a fourth lens group which has a fixed distance from the image plane and which has positive refracting power; wherein the first lens group, the second lens group, the third lens group and the fourth lens group are arranged in order from an object side to an image plane side, wherein the third lens group has an aperture stop and a plurality of lenses, wherein a plurality of the lenses in the third lens group include at least one lens having positive refracting power and at least one lens having negative refracting power, and wherein in the third lens group, the aperture stop, the lens having the positive refracting power and the lens having the negative refracting power are arranged in order from the object side to the image plane side.