Value documents and other articles having taggants that exhibit delayed maximum intensity emissions, and methods and apparatus for their authentication
US8742369B2 · kind B2 · utility
4Cited by
3References
20Claims
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Key dates
| Filing date | Oct 18, 2011 |
| Grant date | Jun 3, 2014 |
| Priority date | — |
| Expiry date | Jul 9, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07D7/1205
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Value documents or other articles having authentication features, authentication apparatuses, and methods of authentication are provided that relate to the use of taggants that absorb radiation from an illumination source and emit radiation in a manner that has a maximum intensity occurring a duration of time after the illumination source has been switched off. The taggants include a crystalline composition comprising a host crystal lattice doped with a first rare earth active ion, and in some examples a second rare earth active ion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.