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:
Jul. 27, 2021
Filed:
Feb. 28, 2020
Seiko Epson Corporation, Tokyo, JP;
Hirotaka Yanagisawa, Azumino, JP;
Eiji Morikuni, Matsumoto, JP;
SEIKO EPSON CORPORATION, Tokyo, JP;
Abstract
A projection optical system has a first optical system and a second optical system. The first and second optical systems are disposed in order from a demagnification side toward a magnification side. An intermediate image is formed between a demagnification-side imaging surface and a magnification-side imaging surface. The second optical system is an optical element having a first transmission surface, reflecting surface, and second transmission surface in order from the demagnification side toward the magnification side. The first transmission surface and reflecting surface are located at one side, and the second transmission surface is located at the other side with respect to the optical axis. The reflecting surface has a concavely curved surface shape. The second transmission surface has a convexly curved surface shape protruding toward the magnification side. The optical element has a first member and a second member different in refractive index.