Verfahren zur Gravur von Druckformen

摘要

The present invention relates to a method for engraving printing blocks (3) for rotogravure on a printing cylinder (1) in an electronic engraving machine which comprises an engraving member (5) actuated by an engraving control signal (GS). The engraving member is used for engraving line by line a series of small-size cups in the printing cylinder (1), wherein said cups are arranged in an engraving raster. Thanks to the positioning of the members to be engraved (4) in the printing block (3), it is possible to establish the cylinder layout of said printing block under visual control in a working station (23). The data (GD) necessary for engraving the printing block (3) are determined from the engraving data (GD') of individual members (4) according to the cylinder layout. During a test phase and before the engraving process, small-size reference cups are engraved in a test area (26) on the printing cylinder (1) and their geometrical dimensions are estimated in order to calibrate the engraving control signal (GS). In order to prevent any wrong positioning of the test area (26) on the printing cylinder (1), the size and localisation of said area (26) are determined by a marking process according to the cylinder layout and before the printing block is engraved.