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:
Oct. 14, 2025
Filed:
Mar. 29, 2023
Seiko Epson Corporation, Tokyo, JP;
SEIKO EPSON CORPORATION, Tokyo, JP;
Abstract
A projection system includes a first lens group, an aperture diaphragm, and a second lens group. A reduction side of the second lens group is telecentric. The first lens group includes a first sub-lens group having negative power and a second sub-lens group having positive power. Between a lens located at the most reduction side of the first sub-lens group and a lens located at the most enlargement side of the second sub-lens group, an air gap wider than air gaps between the other lenses adjacent to each other is provided. A lens located at the most reduction side in the first lens group is a positive lens. A cemented lens of the second lens group includes a first lens having negative power, a second lens having positive power, and a third lens having negative power from an enlargement side toward a reduction side. ω>40.