Security paper with authenticity features in the form of luminescing substances
AssigneeGAO Gesellschaft fur Automation und Organisation mbH
InventorsWittich Kaule, Gerhard Schwenk, Gerhard Stenzel
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Abstract
Security papers with luminescing authenticity features worked into them or printed on them. The authenticity features used consist of a luminophore and one or more absorbing materials by which the emission and/or the excitation spectrum of the luminophore is changed in detectable fashion. The dyestuff can be present as an admixture to the luminophore, as a coating of a luminophore layer or as a coating on luminophore powder grains. For checking the authenticity of documents the emission spectrum of the luminophore is not used but the change generated by the technology used in the emission or excitation spectra.
Claims22
Security document with authenticity features comprising:
- a substrate material supporting a luminescing substance, having a known emission spectrum and a known excitation spectrum, said luminescing substance comprising a luminophore and an absorbing substance, said absorbing substance having an absorption spectrum which partly overlaps at least one of said known emission spectrum and said known excitation spectrum of the luminophore whereby said luminescing substance has an emission spectrum which is characteristically altered from said known emission spectrum whereby said characteristically altered portion of the spectrum is used for authentication of the security document.
Dependencies are inferred from the claim text.