US 11,656,436 B2
Optical imaging system
Xue Gao, Ningbo (CN); Jianke Wenren, Ningbo (CN); Fujian Dai, Ningbo (CN); and Liefeng Zhao, Ningbo (CN)
Assigned to Zhejiang Sunny Optical Co., Ltd, Ningbo (CN)
Filed by Zhejiang Sunny Optical Co., Ltd, Ningbo (CN)
Filed on Jul. 24, 2020, as Appl. No. 16/937,699.
Claims priority of application No. 201910694639.7 (CN), filed on Jul. 30, 2019.
Prior Publication US 2021/0033825 A1, Feb. 4, 2021
Int. Cl. G02B 13/00 (2006.01); G02B 9/62 (2006.01); G02B 13/02 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 9/62 (2013.01); G02B 13/02 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An optical imaging system, sequentially from an object side to an image side of the optical imaging system along an optical axis, comprising:
a first lens having positive refractive power;
a second lens having refractive power;
a third lens having negative refractive power;
a fourth lens having refractive power with a convex object-side surface and a concave image-side surface;
a fifth lens having refractive power; and
a sixth lens having negative refractive power,
wherein Semi-FOV<15°, and
1.9 mm<TTL*ImgH/f<2.7 mm,
where Semi-FOV is half of a maximal field-of-view of the optical imaging system, TTL is a distance along the optical axis from an object-side surface of the first lens to an imaging plane of the optical imaging system, ImgH is half of a diagonal length of an effective pixel area on the imaging plane and f is an effective focal length of the optical imaging system, and
wherein 1.0<(f234−f56)/f<1.8,
where f234 is a combined focal length of the second lens, the third lens, and the fourth lens; f56 is a combined focal length of the fifth lens and the sixth lens; and f is the effective focal length of the optical imaging system.