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:
Sep. 05, 2000
Filed:
Dec. 18, 1998
Richard G Gingerich, Towanda, PA (US);
Clarence D Vanderpool, Towanda, PA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
An electroluminescent phosphor containing an effective amount of bismuth to increase the half-life of the phosphor compared to the half-life of the phosphor without the bismuth. The phosphor is produced by the method comprising the steps of preparing the electroluminescent phosphor; adding granular, elemental bismuth to the bottom of a quartz reaction vessel; covering the bismuth with a layer of quartz wool; placing the phosphor on top of the quartz wool; evacuating the reaction vessel to about 750-760 mm Hg and sealing the vessel; and heating the vessel to between about 500 to 700.degree. C. for about 24 to 72 hours.