Apparatus for making printing plates and other materials having a surface in relief

摘要

A surface in relief is formed by scanning coherent radiation over a surface defined by a thin film supported upon a plastic substrate. The wave length of the coherent radiation is chosen so that it is absorbed by the film and hence removes portions of the film exposing the substrate. The coherent radiation for removing the film may be switched on and off or otherwise modified so as to write information on the surface. Thereafter, the surface is again scanned by coherent radiation of a wave length that is reflected by the film but absorbed by the plastic substrate thereby removing portions of the plastic exposed by the coherent radiation. The film may or may not then be completely removed leaving a pattern in relief upon the surface of the substrate.