SYSTEM FOR REGIONAL ETCHING OF HOLOGRAPHIC MICROETCHINGS, DIFFRACTION GRATINGS, KINOGRAMS, PIXELGRAMS OR OTHER OPTICAL ELEMENTS ON SHEETS

摘要

In accordance with a first solution there is used an electroformed printing plate bearing microetchings in high relief. In accordance with another solution there is used for the microetching an etching unit in which: the embossing roll bears and electroformed printing plate bearing the regional microetchings at the same height as the other regions of the plate which are not etched, and the counterthrust roll rotates synchronously with the embossing roll and displays on its surface high reliefs in the regions designed to face the microetched regions of the printing plate during the etching process.