US 11,656,444 B2
Zoom lens group
Jianke Wenren, Yuyao (CN); Fujian Dai, Yuyao (CN); and Liefeng Zhao, Yuyao (CN)
Assigned to Zhejiang Sunny Optics Co., Ltd.
Filed by Zhejiang Sunny Optics Co., Ltd, Yuyao (CN)
Filed on May 27, 2021, as Appl. No. 17/332,455.
Claims priority of application No. 202010638071.X (CN), filed on Jul. 6, 2020.
Prior Publication US 2022/0003976 A1, Jan. 6, 2022
Int. Cl. G02B 15/14 (2006.01)
CPC G02B 15/144 (2019.08) 14 Claims
OG exemplary drawing
 
1. A zoom lens group, sequentially from an object side to an image side of the zoom lens group along an optical axis, comprising:
a first lens group;
a second lens group;
a third lens group having positive refractive power; and
a fourth lens group having negative refractive power;
wherein the zoom lens group continuously zooms by changing positions of the second lens group, the third lens group, and the fourth lens group along the optical axis,
wherein a distance TTL from an object-side surface of a lens in the first lens group closest to the object side to an imaging plane of the zoom lens group along the optical axis, and a total effective focal length fw of the zoom lens group in a wide-angle state satisfy:
2.0<TTL/fw<3.0.