DIFFRACTION SURFACE STRUCTURE Russian patent published in 2002 - IPC

FIELD: protective element for authenticating bank notes, currency documents, securities, etc. SUBSTANCE: surface structure in the form of optical diffraction protective element bearing easily read-out information for identifying difficult-to-counterfeit surface structure has N visually different forms composed of extremely thin embossed diffraction structures or flat reflecting surfaces, or surfaces incorporating absorbing or dissipating structures; N forms brought together have at least one common independent surface element divided into surface sections disposed in desired structure independent of N forms; disposition of surface sections is invisible for unaided eye; each surface section is covered either with individual extremely thin diffraction structure or with structure possessing absorbing or dissipating properties. EFFECT: facilitated identification of surface structure; enhanced reliability of counterfeit protection. 22 cl, 9 dwg, 2 tbl