Heidelberger Druckmaschinen Ag

Gerhard Loeffler

Helmut Kipphan

Werner Huber

Wolfgang Geissler

Harald Bucher

Bernd Kistler

Clemens Rensch

Gerhard Fischer

Anton Rodi

Nikolaus Pfeiffer

Manfred Schneider

A method for regulating inking of a printing press. The method includes a first step of providing a picture taking device, a closed-loop control device, and a printed product having a surface with a printed image. A second step of printing a print control strip on the surface next to the printed image. A third step of deriving first picture signals from the print control strip and deriving second picture signals from the printed image with the picture taking device. A fourth step of using the closed-loop control device for deriving actual values representing inking of the print control strip from the first picture signals and comparing the actual values to desired values for deriving resultant comparison values. A fifth step of determining ink adjusting signals for controlling ink distribution devices from the resultant comparison values for varying inking of the print product until a desired value is reached during a printer tuning phase. A sixth step of generating an OK signal when the desired value is reached. A seventh step of using the closed-loop control device for deriving further actual values representing inking of the printed image from the second picture signals and comparing the further actual values to further desired values for creating further resultant comparison values. Lastly, one determines further ink adjusting signals for controlling the ink distribution devices from the further resultant comparison values for varying inking of the printed product.

Method for regulating inking during printing operations of a printing

Process and arrangement for controlling or regulating operations carried

In a process for assessing the quality of a print image produced on a printing material in a multi-color printing process, in which signals which reproduce print-image elements are generated with an image-recording arrangement, in which color values are derived from the signals for every print-image element, in which the color values are transformed into color measures of a predetermined color space, in which color distances between an actual color site and a desired reference color site are determined for the print-image elements, correction variables of the control elements (18, 19, 20, 21), whose effect on a control element (18) would cause the actual color sites to be as close as possible to the reference color sites, are calculated from the color distances and stored in memory, that the color-distance vectors (.DELTA.L.sub.Bn, .DELTA.a.sub.Bn, .DELTA.b.sub.Bn) and color distances (.DELTA.E.sub.Bn) of at least one predetermined reference image (B.sub.n) with homogeneous area coverage are determined as a measure for the quality in the said print-image region, the correction variables (.DELTA.s.sub.B, .DELTA.s.sub.C, .DELTA.s.sub.M, .DELTA.s.sub.Y) which are necessary for compensation of the color distances (.DELTA.E.sub.Bn) in the reference image (B.sub.n) corresponding to the previously calculated and stored correction variables.

Method for assessing the quality of a multi-color print image

Device for parallel image inspection and inking control on a printed

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Walldorf, Germany

Gerhard Loeffler