US 11,719,913 B2
Optical imaging system including seven lenses of ++-+-+-, - +-+-+-, ++---+- or ++-+++- refractive powers
Saifeng Lyu, Zhejiang (CN); Mengna Tang, Zhejiang (CN); Fujian Dai, Zhejiang (CN); and Liefeng Zhao, Zhejiang (CN)
Assigned to ZHEJIANG SUNNY OPTICAL CO., LTD., Zhejiang Province (CN)
Filed by Zhejiang Sunny Optical Co., Ltd, Zhejiang (CN)
Filed on Aug. 11, 2020, as Appl. No. 16/990,425.
Claims priority of application No. 201910803288.9 (CN), filed on Aug. 28, 2019.
Prior Publication US 2021/0063698 A1, Mar. 4, 2021
Int. Cl. G02B 13/00 (2006.01); G02B 9/64 (2006.01); G02B 13/06 (2006.01)
CPC G02B 13/0045 (2013.01) [G02B 9/64 (2013.01); G02B 13/06 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An optical imaging system consisting of seven lenses, sequentially from an object side to an image side of the optical imaging system along an optical axis, comprising:
a first lens having refractive power with a convex object-side surface;
a second lens having positive refractive power;
a third lens having refractive power;
a fourth lens having refractive power;
a fifth lens having refractive power;
a sixth lens having positive refractive power with a convex image-side surface; and
a seventh lens having negative refractive power,
wherein f*tan(FOV/2)>4.0 mm, and 0<f/R9<1.0,
where f is an effective focal length of the optical imaging system, FOV is a maximum field-of-view of the optical imaging system, and R9 is a radius of curvature of an object-side surface of the fifth lens,
wherein 10*|R2−R3|/f<0.5,
where R2 is a radius of curvature of an image-side surface of the first lens, R3 is a radius of curvature of an object-side surface of the second lens, and f is the effective focal length of the optical imaging system; and
wherein 0<T12/(CT2−CT1)≤0.2,
where T12 is the spaced interval between the first lens and the second lens along the optical axis, CT1 is the center thickness of the first lens along the optical axis, and CT2 is the center thickness of the second lens along the optical axis.