Patent ID: 9250421
Filing Date: 2016-02-02
CPC Classification: G02B,H04N

Claim Text:
1. A zoom lens comprising: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; and a rear lens group having a positive refractive power, wherein the first lens group, the second lens group, the third lens group, and the rear lens group are sequentially disposed from an object side, wherein during zooming from a wide angle position to a telephoto position, an interval between the first lens group and the second lens group is increased, and an interval between the second lens group and the third lens group is decreased, wherein the rear lens group comprises, sequentially from the object side, a first sub-group having a positive refractive power, a second sub-group having a negative refractive power, and a third sub-group having a positive refractive power, and focusing in the nearest position is performed by moving the second sub-group toward an image surface side, wherein the first sub-group comprises wherein the zoom lens satisfies the following conditions: wherein “frt” denotes a focal length of the rear lens group at the telephoto position, “fa” denotes a focal length of the first sub-group, “fb” denotes a focal length of the second sub-group, and “ft” denotes a focal length of the zoom lens at the telephoto position.