PRINTED DOCUMENT WITH LUMINESCENT AUTHENTICITY SIGNS MADE WITH USE OR CRYSTAL LATTICE OF BASE Russian patent published in 2002 - IPC

FIELD: documents protected against forgery. SUBSTANCE: printed security document has at least one authenticity sign made with the aid of luminescent agent on base of crystal lattice alloyed by at least one rare-earth metal which absorbs radiation practically over entire visible area of spectrum; it is excited in essential areas of spectrum and is partially transparent in wave band of 0.8 to 1.1 mcm. Rare-earth metal emits radiation wave length band of 0.8 to 1.1 mcm and crystal lattice of base includes chromium used as radiation absorbing agent in concentration sufficient for intensification of radiation of luminescent agent. Ytterbium, praseodymium or neodymium may be used as rare-earth metal. Protective element has substrate and luminescent agent on base crystal lattice alloyed by at least one rare-earth metal. Luminescent agent may be embedded in substrate or may be applied on it in form of layer. Substrate may be made from plastic, paper, protective filament made from compounded fibers in form of platen or label. EFFECT: high level of protection. 27 cl, 6 dwg