US 12,222,466 B2
Optical imaging system
Lili Miao, Yuyao (CN); Litong Song, Yuyao (CN); Fujian Dai, Yuyao (CN); and Liefeng Zhao, Yuyao (CN)
Assigned to ZHEJIANG SUNNY OPTICS CO., LTD., Yuyao (CN)
Filed by Zhejiang Sunny Optics Co., Ltd., Yuyao (CN)
Filed on Jan. 7, 2022, as Appl. No. 17/571,405.
Claims priority of application No. 202110307181.2 (CN), filed on Mar. 23, 2021.
Prior Publication US 2022/0308314 A1, Sep. 29, 2022
Int. Cl. G02B 13/00 (2006.01); G02B 9/34 (2006.01)
CPC G02B 13/004 (2013.01) [G02B 9/34 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical imaging system, along an optical axis from an object side to an image side sequentially comprising:
a first lens having negative refractive power;
a second lens having positive refractive power, and an object-side surface of the second lens being a convex surface;
a third lens having refractive power, an object-side surface of the third lens at a paraxial area being a convex surface, and an image-side surface of the third lens at the paraxial area being a convex surface; and
a fourth lens having refractive power, and an object-side surface of the fourth lens at the paraxial area being a concave surface,
wherein a number of lenses having refractive powers in the optical imaging system is four,
a total effective focal length f of the optical imaging system and half of a maximum field-of-view Semi-FOV of the optical imaging system satisfy: f×tan(Semi-FOV)≥4.0 mm; and
the total effective focal length f of the optical imaging system and an entrance pupil diameter EPD of the optical imaging system satisfy: f/EPD<2.35.