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:
Jan. 20, 2015
Filed:
Aug. 22, 2011
Iwao Mitsuishi, Tokyo, JP;
Yumi Fukuda, Tokyo, JP;
Aoi Okada, Tokyo, JP;
Naotoshi Matsuda, Kanagawa, JP;
Shinya Nunoue, Chiba, JP;
Keiko Albessard, Kanagawa, JP;
Masahiro Kato, Kanagawa, JP;
Iwao Mitsuishi, Tokyo, JP;
Yumi Fukuda, Tokyo, JP;
Aoi Okada, Tokyo, JP;
Naotoshi Matsuda, Kanagawa, JP;
Shinya Nunoue, Chiba, JP;
Keiko Albessard, Kanagawa, JP;
Masahiro Kato, Kanagawa, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A light emitting device includes a light emitting element that emits light having a wavelength of 250 nm to 500 nm and a fluorescent layer that is disposed on the light emitting element. The fluorescent layer includes a phosphor having a composition expressed by the equation, ((MEu)SiAlON), and an average particle diameter of 12 μm or more, wherein in the equation, M is an element that is selected from IA group elements, IIA group elements, IIIA group elements, IIIB group elements except Al, rare-earth elements, and IVB group elements, and x1, y, z, u, and w satisfy each of the inequalities simultaneously, that is to say each of the following inequalities is satisfied by the choice of values of the identified paramaters within the noted ranges of 0<x1<1, −0.1<y<0.3, −3<z≦1, −3<u−w≦1.5, 2<u, w<21.