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. 01, 1992
Filed:
Dec. 21, 1990
Applicant:
Inventors:
Arunava Dutta, Chestnut Hill, MA (US);
Ernest A Dale, Hamilton, MA (US);
Leonard V Dullea, Peabody, MA (US);
Assignee:
GTE Products Corporation, Danvers, MA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B05D / ; B05D / ;
U.S. Cl.
CPC ...
427-8 ; 427 67 ; 427 68 ; 427595 ; 313485 ;
Abstract
A an europium doped yttrium oxide red phosphor in a water base phosphor coating suspension is checked for degraded phosphor by (a) centrifuging the suspension, (b) separating an aqueous portion from a solids portion, (c) exposing a surface portion of said solids to UV radiation at 254 nm or 365 nm, (d) observing the presence or absence of fluorescence from said top layer of solids wherein the absence of fluorescence is indicative of a degraded phosphor.