Patent ID: 6344261
Filing Date: 2002-02-05
Classification: B41M,B42D,C09K,G06K,Y10S,Y10T

Abstract:
Printed valuable document with at least one authentication feature comprising a luminescent substance based on a host lattice doped with at least one rare earth metal, which largely absorbs throughout the visible region of the spectrum, is excitable in substantial parts of the visible region of the spectrum, and is at least partially transparent at least in the wavelength range between 0.8 &mgr;m and 1.1 &mgr;m, whereby the rare earth metal emits in the wavelength range between 0.8 &mgr;m and 1.1 &mgr;m, and the host lattice contains chromium as an absorptive substance in such a concentration that amplification of the emission by the luminescent substance takes place.