Heidelberger Druckmaschinen Ag

Dr. Ing. Rudolf Hell Gmbh

Hell Gravure Systems Gmbh

Christian Wiechering

Bernd L&uuml;bcke

Dieter Fangmeyer

Rolf Hupka

Armin Jacht

In a method for processing signals in an electronic engraving machine for engraving printing forms, in particular printing cylinders used for rotogravure, an engraving control signal is obtained by superimposing engraving data, representing tone values between &ldquo;white&rdquo; and &ldquo;black&rdquo; which are to be engraved, with a periodic screen signal for generating a gravure screen. The engraving control signal guides the lifting movement of the stylus of an engraving element. As a result of the lifting movement of the stylus, a series of cups arranged in the gravure screen is engraved on the printing form. To compensate an incorrect lifting movement of the stylus (rebound effect, lag effect), the engraving data undergo digital filtering before superposition of the gravure screen.

Method for signal processing

The invention relates to a method and a circuit for processing signals in an electronic graving machine, in which a series of cups arranged in a gravure screen is engraved in a printing cylinder by a burin of a graving element guided by an engraving control signal (G). In a digital signal processor ( ), a transfer function is determined from function value data used to calculate a periodic screen signal for producing the gravure screen; from adjustment data for adjusting the depth of cut; from digital adjustment parameters for calibrating &ldquo;light&rdquo; (white) and &ldquo;dark&rdquo; (black); and from control data (SD). The transmission coefficients of the transmission function and/or the transmission function can be modified by the control data (SD). The engraving data (GD), which represent the different tone values between &ldquo;black&rdquo; and &ldquo;white&rdquo; which are to be engraved, are then converted into engraving control data (GSD) in the digital signal processor ( ) after the transmission function. The engraving control data (GSD) undergo digital-analog conversion and the analog engraving control signal (G) is amplified in a current amplifier ( ) and fed to the graving element.

Signal processing method

Mode of operating of a circuit arrangement for improving the bounce

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Kiel, Germany

Christian Wiechering