Patent ID: 8693107

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, and a fourth lens group having a positive refracting power arranged in order from an object side to an image side along an optical axis, wherein the second lens group includes three lenses, that is, a negative lens, a positive lens, and a negative lens in order from the object side to the image side, wherein the third lens group includes three lenses, that is, a positive lens, a negative lens, and a positive lens in order from the object side to the image side and wherein the first lens group, the second lens group, the third lens group and the fourth lens group move along the optical axis to and between a wide-angle end state and an intermediate state and to and between the intermediate state and a telephoto end state such that: in the wide-angle end state, the first lens group is disposed at first lens group position 1 A, the second lens group is disposed at a second lens group position 2 A, the third lens group is disposed at a third lens group position 3 A and the fourth lens group is disposed at a fourth lens group position 4 A, in the intermediate state, the first lens group is disposed at a first lens group position 1 B which is forwardly of the first lens group position 1 A toward the object side, the second lens group is disposed at a second lens group position 2 B which is rearwardly of the second lens group position 2 A toward the image side, the third lens group is disposed at a third lens group position 3 B which is forwardly of the third lens group position 3 A toward the object side and the fourth lens group is disposed at a fourth lens group position 4 B which is forwardly of the fourth lens group position 4 A toward the image side, and in the telephoto end state, the first lens group is disposed at a first lens group position 1 C which is forwardly of the first lens group position 1 B toward the object side, the second lens group is disposed at a second lens group position 2 C which is either the same location of second lens group position 2 B or substantially the same location of second lens group position 2 B being bias slightly incrementally forward of the second lens group position 2 B toward the object side, the third lens group is disposed at a third lens group position 3 C which is forwardly of the third lens group position 3 B toward the object side and the fourth lens group is disposed at a fourth lens group position 4 C which is rearwardly of the fourth lens group position 4 B toward the image side.