Patent ID: 9500876
Filing Date: 2016-11-22
CPC Classification: G02B

Claim Text:
1. A zoom lens unit comprising: in order from an object side to an image plane side, a first lens group with positive refractive power; a second lens group with negative refractive power; a third lens group with negative refractive power; and a fourth lens group with positive refractive power; wherein the first lens group and the fourth lens group are fixed relative to the image plane, while the second lens group moves toward the image plane side and the third lens group moves when changing a magnification ratio from a wide-angle end to a telephoto end, the fourth lens group includes a resin lens with negative refractive power, and at least one positive lens, and said at least one positive lens of the fourth lens group fulfils conditions (1), (2), and (3): where n wherein a condition (4) is fulfilled: where f