Patent ID: 7277629

Claim:
A zoom lens, comprising: a first lens group having a positive refracting power; a second lens group having a negative refracting power; a third lens group having a positive refracting power; a fourth lens group having a positive refracting power; and a fifth lens group having a positive refracting power, wherein the first lens group, the second group lens, the third lens group, the fourth lens group, and the fifth lens group are arranged in succession, wherein the zoom lens is configured such that when zooming from a short focal length end toward a long focal length end, the second lens group lens moves toward the third lens group and the fourth lens group moves toward a side of the third lens group, and wherein when a distance from a first lens surface of the zoom lens to the imaging plane of the zoom lens at the long focal length end is Σd, a synthesized focal length of the first lens group through the fifth lens group is fw, and a synthesized focal length of the first lens group through the fifth lens group is ft, a following conditional formula is satisfied: 1.45<Σd/(ft−fw)<2.2.