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. 09, 1997
Filed:
Jan. 03, 1997
Chung Nin Chau, Sayre, PA (US);
Osram Sylvania Inc., Danvers, MA (US);
Abstract
A surface modified phosphor powder exhibiting increased lumen maintenance. At the outer surface of each phosphor particle, the cations of the phosphor material have been replaced by other cations, e.g., a metal or metalloid cation such as aluminum, barium, calcium, lanthanum, magnesium, strontium, yttrium, zinc, titanium, tantalum, boron, or silicon. The phosphor powder is chemically modified by forming a suspension of phosphor particles in a liquid medium including the metal or metalloid ions in solution. The phosphor suspension is stirred for a time sufficient to permit an ion exchange reaction in which the metal or metalloid ions are substituted for cations of the phosphor to form a layer of the desired metal or metalloid compound at the phosphor outer surface.