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:
May. 03, 1994
Filed:
Mar. 31, 1992
A Gary Sigai, Lexington, MA (US);
Keith A Klinedinst, Marlboro, MA (US);
GTE Products Corporation, Danvers, MA (US);
Abstract
A fluorescent lamp providing improved maintenance and brightness includes an alkaline earth halophosphate (Cool-White) phosphor, e.g. a calcium halophosphate phosphor, having a continuous protective bilayer coating of alumina surrounding silica surrounding the phosphor particles. The lamp may be a high color rendition fluorescent lamp in which a first layer of alkaline earth halophosphate phosphor coats an inner surface of the lamp envelope, and a second layer of phosphor overlies the first layer of phosphor. The second layer of phosphor is a mixture of red, blue and green emitting phosphors, at least one of these being a zinc silicate phosphor. Each of the alkaline earth halophosphate and zinc silicate phosphors have a bilayer coating in which a coating of alumina surrounds a coating of silica which surrounds the phosphor.