The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 03, 2022
Filed:
Mar. 19, 2020
Zhejiang Dahua Technology Co., Ltd., Zhejiang, CN;
ZHEJIANG DAHUA TECHNOLOGY CO., LTD., Hangzhou, CN;
Abstract
The present disclosure is related to a lens systems. The lens system includes, in order from an object side to an image side, a first lens group Ghaving negative refractive power, a second lens group Ghaving positive refractive power, a third lens group Ghaving positive refractive power, and the lens system satisfies the following condition: and at least partial of Gis made of material satisfying the following condition: Vd>g and dn/dt≤h, wherein a, b, c, d, e, f, g and h are constants, frepresents a focal length of Gfrepresents a focal length of Gfrepresents a focal length of Gf' represents a focal length of the lens system, Vd represents an abbe constant, n represents a refractive index, t represents temperature, and dn/dt represents a differential of refractive indices against temperature.