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:
Dec. 22, 1998
Filed:
Mar. 13, 1997
Naotoshi Matsuda, Machida, JP;
Masaaki Tamatani, Fujisawa, JP;
Miwa Okumura, Kawasaki, JP;
Keiko Albessard, Yokohama, JP;
Kazuhiro Kawasaki, Fujisawa, JP;
Seiji Yokota, Hiratsuka, JP;
Shinjiro Motoki, Hiratsuka, JP;
Yoshiaki Inoue, Atsugi, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Neturen Co., Ltd., Tokyo, JP;
Abstract
A raw material prepared by washing a phosphor powder containing a phosphor host material and an activator with an acid solution, followed by drying the washed powder, is heated within a thermal plasma at a temperature which permits partially melting the phosphor, followed by cooling and subsequently subjecting the resultant phosphor at 1200.degree. to 1700.degree. C., thereby manufacturing spherical phosphor particles having a concentration gradient in a radial direction.