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:
Aug. 14, 1990
Filed:
Oct. 10, 1989
Applicant:
Inventors:
Joseph E Ritsko, Towanda, PA (US);
Anthony F Kasenga, Towanda, PA (US);
Scott A Renninger, Kreamer, PA (US);
Assignee:
GTE Products Corporation, Stamford, CT (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C09K / ;
U.S. Cl.
CPC ...
2523 / ;
Abstract
A europium activated yttrium oxide phosphor is prepared as follows. Europium oxide is dissolved in nitric acid. Ammonium hydroxide is added to precipitate europium hydroxide, which is then dissolved in citric acid monohydrate to form europium citrate solution. Yttrium oxide powder is added to the solution to form a slurry, which is then spray dried. The spray dried powder is fired at a high temperature to form the phosphor.