METHOD OF FORMING COLOUR SECURITY IMAGE WITHIN SHEET MATERIAL VISIBLE IN TRANSMITTED LIGHT AND REFLECTED ON FRONT AND BACK SURFACES OF SAID MATERIAL BY SET OF COAXIAL ENTRY HOLES AND SHEET MATERIAL THEREFOR

摘要

FIELD: physics.SUBSTANCE: method includes forming an image within a sheet material comprising a monolayer of transparent microspheres, partially immersed in a reflecting layer deposited on a plastic substrate and containing a solid solution of fluorescent or luminiferous coloured particles. A plastic layer and a metal foil layer are successively deposited on a monolayer of microlenses. Pulsed laser radiation forms holes in the foil layer at given points and the plastic layer under the foil, the material of the reflecting layer and the plastic substrate are melted within the laser spot. Microlenses are melted with a compact laser beam within a reduced laser spot and fused with each other. A through-hole is formed in the plastic substrate. Clusters of microlenses with crystals formed thereon with nodules of the coloured particles of the reflecting layer and fused microlenses form points of the colour security image visible in transmitted light and reflected on surfaces of the sheet material by the set of coaxial holes.EFFECT: easy recognition of a security feature, which provides reliable counterfeit protection of articles.6 cl, 9 dwg