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:
Sep. 24, 2019
Filed:
Feb. 09, 2016
Kazuhiro Fujita, Tokyo, JP;
Takahiro Kado, Kanagawa, JP;
Kazuhiro Fujita, Tokyo, JP;
Takahiro Kado, Kanagawa, JP;
RICOH COMPANY, LTD., Tokyo, JP;
Abstract
This invention is concerning an illumination device that can obtain illumination light efficiently. An illumination deviceused in, for example, a projection display apparatus includes a light source and a light tunnel. The light tunnelincludes a light incident port, a light emission port, a light guide path, a reflection surfacesurrounding the light guide path, a phosphor layerthat generates fluorescent light LF having a different wavelength range from that of excitation light LE when being excited by the excitation light LE, a condensing optical systemthat diverges the excitation light LE in the vicinity of the light incident portand guides the diverged light into the light tunnelto irradiate the phosphor layer, and a wavelength selection element that reflects the fluorescent light LF toward the light emission port