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:
May. 12, 2015
Filed:
Apr. 21, 2011
Hideyuki Emoto, Tokyo, JP;
Toshiaki Nagumo, Tokyo, JP;
Hideyuki Emoto, Tokyo, JP;
Toshiaki Nagumo, Tokyo, JP;
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
An object of the present invention is to provide a phosphor that is combined with a blue LED to achieve white light at a low color temperature as if singly, has a broad fluorescence spectrum for excellent color rendering properties, has a high luminous efficiency, is thermally and chemically stable like conventional nitride-based phosphors, and has a small decrease in luminance at high temperatures. Another object of the present invention is to provide a light emitting device using such a phosphor. The present invention relates to a β-sialon that is expressed by the general formula, SiAlON:Eu (0<z<4.2). In the β-sialon, P2/P1 is not lower than 0.5 and not higher than 1000 (P1 representing the height of an absorption line appearing in the region where g is 2.00±0.02 in a first derivative spectrum obtained by an electron spin resonance technique at 25° C., P2 representing the difference between the maximum value and the minimum value in a spectrum on the lower magnetic field side of P1).