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:
Apr. 09, 2019
Filed:
Mar. 16, 2017
Seiko Epson Corporation, Tokyo, JP;
Hayato Matsuki, Suwa, JP;
Osamu Yokoyama, Shiojiri, JP;
SEIKO EPSON CORPORATION, Tokyo, JP;
Abstract
In an optical element, a first diffraction grating, a second diffraction grating, a third diffraction grating, and a fourth diffraction grating are formed in each of a first surface of a first substrate, a fourth surface of a second substrate, a fifth surface of a third substrate, and an eighth surface of a fourth substrate. Each substrate is fixed by (a first adhesive layer, second adhesive layer, and a third adhesive layer) adhesive layers including a gap material. A first filler with a refractive index equal to that of the first substrate and the second substrate is filled between the first substrate and the second substrate and a third filler formed of air or a medium with a refractive index equal to that of air is filled between the second substrate and the third substrate.