Patent ID: 7046452

Claim:
A zoom lens formed of only three lens groups, arranged along an optical axis in order from the object side as follows: a first lens group having negative refractive power; a second lens group having positive refractive power and including a stop for controlling the amount of light that passes through the zoom lens; a third lens group having positive refractive power; wherein during zooming from the wide-angle end to the telephoto end, the first lens group moves first toward the image side and then toward the object side, the second lens group moves monotonically toward the object side and closer to the first lens group, the third lens group moves first toward the object side and then toward the image side, and the second lens group moves farther from the third lens group; with the zoom lens focused at infinity, the third lens group is closer to the object side at the wide-angle end than at the telephoto end; when focusing from infinity to close range, the third lens group moves toward the object side; and the following conditions are satisfied: 2.0<| f 1 |/f w <2.4 0.29 <f 2 /f 3 <0.37 where f w is the focal length of the entire zoom lens at the wide-angle end, f 1 is the focal length of the first lens group, f 2 is the focal length of the second lens group, and f 3 is the focal length of the third lens group.