COMPOSITION FOR HIDDEN GRAPHIC CHARACTER INFORMATION RECORDS ON DOCUMENTS AND ARTICLES AND A METHOD OF READING IT Russian patent published in 2001 - IPC

FIELD: information storage. SUBSTANCE: composition contains light-sensitive component and polymer film-forming material, the former being based on cooperative luminophor sensitive to IR emission. Luminophor contains powder-like matrix based on glass ceramics, preferably fluoride or fluoride-gallate glasses doped by fluorides of rare-earth elements: ytterbium as sensitizer and erbium as activator. Hidden information is visualized by irradiation of document or article at room temperature with beam of semiconductor minilaser having output power 0.25-1.0 W and wavelength 960-99 nm. Record is read on characters luminescenting in visible wavelength range. EFFECT: increased degree of counterfeit protection and simplified information reading. 3 cl, 3 tbl