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. 29, 1992
Filed:
Dec. 09, 1991
A Gary Sigai, Lexington, MA (US);
GTE Products Corporation, Danvers, MA (US);
Abstract
A method for eliminating carbonaceous contaminants and preventing the hydration/solubilization of the alumina protective coating of a phosphor is described. The method involves the heating a fluidized alumina coated phosphor in a fluidized bed at a temperature and for a period of time sufficient to preclude adversely affecting the protective oxide coating on the phosphor during subsequent water-based suspension processing without detrimentally altering the phosphor. After heating the fluidized phosphor is cooled and then added to a water-based suspension. The conditions for treating a manganese activated zinc silicate phosphor having a protective alumina coating are heating the fluidized phosphor at a temperature between about 700.degree. C. and about 850.degree. C. for a period of time from about 15 minutes to about 20 hours. A fluorescent lamp containing the phosphor prepared by the above described method is also described.