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. 29, 2014
Filed:
Oct. 27, 2010
Masayoshi Ichikawa, Tokyo, JP;
Hironori Nagasaki, Tokyo, JP;
Masayoshi Ichikawa, Tokyo, JP;
Hironori Nagasaki, Tokyo, JP;
Denki Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
Provided is a production method of a β-type sialon fluorescent substance, where luminescence intensity can be improved without adding a metal element other than elements composing a β-type sialon fluorescent substance. Namely, in a production method of a fluorescent substance containing an optically-active element as the luminescence center in a crystal of nitride or acid nitride, a β-type sialon fluorescent substance is produced by a burning process for heat-treating a mixture including metal compound powder and an optically-active element compound; a high-temperature annealing process for heat-treating the burned product after cooling under a nitrogen atmosphere; a rare-gas annealing process for heat-treating the high-temperature annealed product under a rare gas atmosphere; and a process for treating the rare-gas treated product with an acid.