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:
Nov. 24, 2009
Filed:
May. 17, 2007
Michael Karl Crawford, Glen Mills, PA (US);
Kurt Richard Mikeska, Hockessin, DE (US);
Michael Karl Crawford, Glen Mills, PA (US);
Kurt Richard Mikeska, Hockessin, DE (US);
E.I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
The invention is directed to a method by exposing at least a portion of a luminescent coating disposed on a surface of an article to ultraviolet light at one or more preselected wavelengths causing said luminescent coating to exhibit a luminescence spectrum, the luminescence spectrum exhibiting a plurality of intensity peaks that have been priorly determined to create a standard; determining the intensity of at least two peaks in the luminescence spectrum of the coating; determining a peak intensity ratio of the at least two peaks; comparing the peak intensity ratio determined with the standard; and, classifying the article according to whether or not the peak intensity ratio does or does not match the standard; wherein the luminescent coating comprises a particulate luminescent composition comprising a rare earth doped fluoride represented by the formulaREAFOwherein RE represents a three-valent rare-earth element, A is alkaline earth, 0.002≦x≦0.20, and 0≦y≦x.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile