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. 04, 2021
Filed:
Jul. 30, 2019
Aac Acoustic Technologies (Shenzhen) Co., Ltd., Shenzhen, CN;
Haichao Peng, Shenzhen, CN;
Chunhuan Fang, Shenzhen, CN;
AAC Optics (Changzhou) Co., Ltd., Changzhou, CN;
Abstract
A projection lens is disclosed. The projection lens includes, in sequence from an object side to an image side: an object surface, a first lens having positive refractive power, a second lens having negative refractive power, and a third lens having positive refractive power, where a focal length of the entire projection lens is f, a total optical length of the projection lens is TTL, a refractive index of the second lens is n2, a refractive index of the third lens is n3, and the following conditions are satisfied: 1.7≤n2≤2.2; 1.7≤n3≤2.2; and 1.25≤f/TTL≤2.20. The projection lens can effectively reduce the system length, and has good performance stability at different temperatures.