Patent ID: 9423598
Filing Date: 2016-08-23
CPC Classification: G02B

Claim Text:
1. A zoom lens comprising, in order from an object side: a first lens group that has a positive refractive power; a second lens group that has a negative refractive power; a third lens group that has a positive refractive power; and a fourth lens group that has a positive refractive power, wherein the fourth lens group includes, in order from the object side, a first sub-lens group that has a positive refractive power, a second sub-lens group that has a negative refractive power, and a third sub-lens group, wherein during zooming from a wide-angle end to a telephoto end, the first lens group, the first sub-lens group, and the third sub-lens group are stationary in a direction of an optical axis relative to the image plane, the second lens group and the third lens group move in the direction of the optical axis, and the second sub-lens group moves in the direction of the optical axis so as to decrease spacing between the first sub-lens group and the second sub-lens group, and wherein during focusing from an infinite-distance object to a close-range object, the second sub-lens group moves in the direction of the optical axis.