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:
Jul. 06, 1976
Filed:
Mar. 03, 1975
Frederick M Ryan, New Alexandria, PA (US);
Frank M Vodoklys, Wayne, NJ (US);
Abstract
An inorganic fluorescent phosphor consisting of a spotting phosphor and a coding phosphor is employed for tagging purposes, as for example, tagging explosives to provide post detonation information. The spotting phosphor consists of an inorganic fluorescent material which is excited by UV to produce readily detectable band-type emission, but which produces little or no emission at certain excitation wave lengths. The coding phosphor consists of a different inorganic fluorescent material which emits a line-type emission and which fluoresces efficiently at those excitation wave lengths at which the spotting phosphor produces little or no emission. Exemplary spotting phosphors are zinc silicate and calcium silicate activated by manganese, which show no excitation at a UV radiation of 325 nm. Suitable coding phosphors are yttrium vanadate activated by trivalent rare earth ions, such as europium, thulium, erbium, dysprosium or Samarium. This combination of spotters and coding phosphors in cemented phosphor grains employed for tagging purposes enables the quantity of expensive coding phosphors required to be drastically reduced.