Method for producing a laser-printed picture

Abstract

Method for producing a picture on the surface of a substrate by laser-printing comprising the steps of: generating still video information consisting of a series of gradational signals each of which corresponds to each of picture elements within a predetermined frame; preparing a substrate having a surface carbonizable or discolorable with heating; generating a laser beam having a sufficient energy to cause the carbonizing or discoloring of said surface; modulating the laser beam in accordance with said video information; scanning the modulated laser beam in accordance with said video information within said frame; and directing and focusing said scanned laser beam to form a sweeping spot over the surface area of said substrate corresponding to said predetermined frame, thereby producing a graphic pattern consisting of picture elements individually gradationally carbonized or discolored. It is preferred at or after said preparing a substrate, and before said directing and focusing the laser beam to the surface thereof that a carbonizing acceleration agent is applied and penetrated to the surface.

Dependencies are inferred from the claim text.