PAPER SECURITY WITH AUTHENTICITY MARK OF LUMINESCENT MATERIAL

摘要

PCT No. PCT/DE81/00079 Sec. 371 Date Oct. 23, 1981 Sec. 102(e) Date Oct. 23, 1981 PCT Filed May 29, 1981 PCT Pub. No. WO81/03508 PCT Pub. Date Dec. 10, 1981.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.