| 摘要 |
A substrate comprises a periodic line pattern covered by a periodic line structure consisting of cylindrical lenses parallel to a line pattern lenses . The period of the line structure corresponds to the period of the line pattern. The lenses are aligned with the lines of the line pattern. The line s consist of elementary printing points or image points (pixels). The number o f elementary printing points in a period is equal to or greater than 4 and equ al to or less than 16. The height of the cylindrical lenses on apex corresponds to at least a half width of a period and at most to the width of the line pattern width. A modern offset printing method, for example used for securit y printing (for example, for banknotes) makes it possible to attain the impression accuracy about 4 ~m. The elementary printing points are selected such that they are slightly greater than an attainable printing accuracy. Th e inventive fine lens structures can be produced by printing a transparent mas s by means of an intaglio printing method or by stamping of the transparent ma ss by an intaglio-engraving plate. The thus produced micro-refraction image is particularly suitable for an authenticity certificate. |
