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:
Jun. 28, 1983
Filed:
Mar. 11, 1981
Thomas E Peters, Chelmsford, MA (US);
James R McColl, Concord, MA (US);
GTE Laboratories Incorporated, Waltham, MA (US);
Abstract
Manganese-arsenic coactivated zinc silicate phosphors comprising a host of substantially stoichiometric zinc silicate and characterized by enhanced brightness and persistence are prepared by a method which includes a two-step firing schedule. The initial pre-fired phosphor powder blend is formulated with an amount of silicic acid less than or equal to the amount stoichiometrically required for the formation of zinc silicate. Any excess zinc oxide remaining in the mixture following the first firing step is removed by addition of ammonium chloride and a second firing step. The resulting phosphors are substantially free of inert zinc oxide and silica which would otherwise contribute to diminished brightness and persistence.