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US 5,673,112 AGranted
Method for detecting color contamination
AssigneeMAN Roland Druckmaschinen AG
InventorPeter Schramm
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AssigneeMAN Roland Druckmaschinen AG
InventorPeter Schramm
Estimating the term…
A method is described for detecting color contamination in the production of color printed products, in particular printed products which are produced on offset printing machines. By means of densitometric measurements, in which so-called main and subsidiary color density values are determined in each case for one color in a plurality of spectral ranges, it is to be possible in a simple manner to detect color contamination. According to the invention, it is proposed for this purpose to determine a functional interrelation which describes how, in an uncontaminated color sample, the subsidiary color density behaves as a function of the associated main color density. During printing, values of the main and subsidiary color densities for the individual colors are then likewise recorded at measurement locations of sample prints. A difference in the associated subsidiary color densities is formed, the subsidiary color density of the uncontaminated color sample being extrapolated in accordance with the functional interrelation to that value which it has in the case of the detected value of the main color density of the sample. If these differential values exceed given tolerances, a warning notice is given in respect of the color contamination detected.
A method for detecting color contamination in the production of multi-color printed products using color density values determined densitometrically for a plurality of spectral ranges for each color, where a greatest color density value for each color is the main color density and the other color density values are subsidiary color densities, the method comprising the steps of (1) determining the values of the main and the subsidiary color densities at a measurement location printed with an uncontaminated color, (2) determining the values of the main and subsidiary color densities of the same color on a printed sample, (3) and forming the difference between the values of the subsidiary color densities of steps (1) and (2), where the values of the subsidiary color densities of the uncontaminated color are extrapolated from the value of the main color density of the printed sample.
Dependencies are inferred from the claim text.