Patent ID: 6717701
Filing Date: 2004-04-06
Classification: B41C,H04N

Abstract:
A method for signal processing in an electronic engraving machine for engraving a printing form for rotogravure, comprising the steps of:forming engraving control signal values from engraving data that represent predetermined gradations between â€œlightâ€  and â€œdarkâ€  and from a periodic raster signal for generating a raster; before engraving, calibrating the engraving control signal for â€œlightâ€  and â€œdarkâ€  by a light setting value and a dark setting value such that engraved gradations â€œlightâ€  and â€œdarkâ€  correspond to predetermined gradations â€œlightâ€  and â€œdarkâ€ ; for keeping the engraved gradation â€œlightâ€  constant when modifying the gradation â€œdarkâ€  forming a difference value between the old dark setting value and a new dark setting value before the engraving; calculating a new light setting value from an engraving datum for â€œlightâ€ , from the old light setting value, and from the difference value; undertaking an automatic recalibration of the engraving control signal value for â€œlightâ€  with the new light setting value; engraving with an engraving stylus of an engraving element controlled by the engraving control signal values a sequence of cups arranged in the raster into the printing form, engraving depths thereof defining the actually engraved gradations; and implementing with the engraving element a feed motion along the printing form for the engraving of the cups.