Patent US2431885A successfully refreshed from Google Patents.
Patent EP0143744B1 successfully refreshed from Google Patents.
EP0143744B1
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EP
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Method and device for rating the printing quality and/or controlling the ink supply in an offset printing machine, and offset printing machine with such a device
Assignee: Gretag AG
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Filing: 1984-10-29
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Granted: 1988-01-13
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Expires: 2004-10-29
Abstract
No abstract record available.
Inventors
- 👤 Guido Keller
- 👤 Andreas Spiess
- 👤 Hans Ott
- 👤 Rolf Boegli
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 12:27
CPC Classifications
B; B41; B41F; B41F33/00; B41F33/0027; B41F33/0036; B41F33/0045
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
246 words
Process for evaluating printing quality and/or regulating ink feed controls in an offset printing machine (1) in which a printed product (4) which is to be evaluated and a reference, divided in the same manner into a plurality of image elements, are measured photoelectrically by image elements, and compared by image elements, and in which on the basis of the comparison result a quality measure or respectively a setting value is determined for the ink feed control elements (2) of the printing machine (1), characterized in that for each image element of the reference in the form of a printed product (4) which is deemed to be good, or printing plates upon which the printing process is based, reference surface coverages are determined for the individual printing colours, that a weighting factor indicating a measure of the assurance with which the respective surface coverage may be determined is assigned to each image element for each printing colour, that for each image element of the printed product (4) which is to be evaluated the reflectances are measured and therefrom actual surface coverages for the individual printing colours are determined by calculation, that for each image element and the individual printing colours the deviations of the actual surface coverages from the reference surface coverages are determined and weighted with the respectively assigned weighting factors, and that the quality measure or respectively the setting values for the ink feed control elements (2) are determined from the thus weighted deviations.
Claim 2
Dependent Claim
246 words
Process for evaluating printing quality and/or regulating ink feed controls in an offset printing machine (1) in which a printed product (4) which is to be evaluated and a reference, divided in the same manner into a plurality of image elements, are measured photoelectrically by image elements, and compared by image elements, and in which on the basis of the comparison result a quality measure or respectively a setting value is determined for the ink feed control elements (2) of the printing machine (1), characterized in that for each image element of the reference in the form of a printed product (4) which is deemed to be good, or printing plates upon which the printing process is based, reference surface coverages are determined for the individual printing colours, that a weighting factor indicating a measure of the assurance with which the respective surface coverage may be determined is assigned to each image element for each printing colour, that for each image element of the printed product (4) which is to be evaluated the reflectances are measured and therefrom actual surface coverages for the individual printing colours are determined by calculation, that for each image element and the individual printing colours the deviations of the actual surface coverages from the reference surface coverages are determined and weighted with the respectively assigned weighting factors, and that the quality measure or respectively the setting values for the ink feed control elements (2) are determined from the thus weighted deviations.
Claim 3
Dependent Claim
25 words
Process according to Claim 1, characterized in that the weighted deviations are combined to zonal weighted deviations preferably by summation and standardization in print zones.
Claim 4
Dependent Claim
24 words
Process according to Claim 2, characterized in that the zonal weighted deviations are used as setting values for the ink feed control elements (2).
Claim 5
Dependent Claim
35 words
Process according to one of Claims 1 to 3, characterized in that the determination by way of calculation of the surface coverages from the reflectances takes place through preferably iterative solution of the Neugebauer equations.
Claim 6
Dependent Claim
37 words
Process according to one of Claims 1 to 4, characterized in that the extent of the image elements is selected to be approximately 0.25 to 400 mm 2 , preferably approximately 1 to 100 mm 2 .
Claim 7
Dependent Claim
45 words
Process according to one of Claims 1 to 5, characterized in that the weighting factor of each image element for each printing colour is established from the surface coverage, the foreign colour component and as a function of the environment of the respective image element.
Claim 8
Dependent Claim
61 words
Process according to Claim 6, characterized in that the weighting factor of each image element is established for each printing colour as a combination of three partial weights, in which a first partial weight is determined from the surface coverage, a second partial weight from the foreign component and a third partial weight from the environment of the respective image element.
Claim 9
Dependent Claim
45 words
Process according to Claim 7, characterized in that the partial weight dependent on the surface coverage is selected such that it has its maximum value in the case of medium surface coverages and has lower values in the cases of smaller and greater surface coverages.
Claim 10
Dependent Claim
40 words
Process according to Claim 7 or 8, characterized in that the partial weight dependent on the environment is selected such that it increases in value with increasing homogeneity of the surface coverage in the environment of the respective image element.
Claim 11
Dependent Claim
37 words
Process according to one of Claims 7 to 9, characterized in that the partial weight depending on the foreign colour component is selected such that its value increases as the surface coverages in the foreign colours decreases.
Claim 12
Dependent Claim
88 words
Process according to one of Claims 1 to 10, characterized in that for each image element the coordinates are determined in the colour space from the surface coverages, the deviations of the coordinates of the reference are determined from those of the printed product (4) to be evaluated and are weighted with weights, established individually for each image element, which weights indicate the importance for the visual appearance, and that from the thus weighted deviations a quality measure is determined for the alteration of the visual image appearance.
Claim 13
Dependent Claim
65 words
Process according to one of Claims 1 to 11, characterized in that in the case of a printed product (4) found to be good as reference for each image element of same the reflectances in the printing colours are measured and from these reflectances the reference surface coverages are determined by calculation in the same way as for the printed products (4) to be evaluated.
Claim 14
Dependent Claim
64 words
Process according to one of Claims 1 to 11, characterized in that in the case of printing plates as reference for each image element of same the surface coverages are measured and by means of the printing characteristic of the printing machine (1) are converted into surface coverages in print, and that these surface coverages in print are utilised directly as reference surface coverages.
Claim 15
Dependent Claim
75 words
Process according to one of Claims 1 to 11, characterized in that in the case of printing plates as reference for each image element of same the surface coverages are measured and by means of the printing characteristic are converted into reference reflectances to be expected in print, and that from these reference reflectances the reference surface coverages are determined by calculation in the same manner as for the printed products (4) to be evaluated.
Claim 16
Dependent Claim
180 words
Apparatus for evaluating printing quality and/or regulating ink feed controls in an offset printing machine, having a photoelectric scanning device (3) for the printed products (4) while the printing machine (1) is running and also having an electronic system (5) for controlling the scanning device (3) and for evaluating the measured data produced by the scanning device, taking into account a quality measure or setting values for the ink feed control elements (2) of the printing machine, characterized in that the electronic system (5) has means (51) for converting the reflectances detected by the scanning device into surface coverages, means (53) for determining weighting factors by means of the calculated surface coverages, means (56) for determining the deviations of the surface coverages from printed products to be examined with respect to the surface coverages of a reference printed product, means (54, 55, 57-59) for the weighting of these deviations with the weighting factors and means for summing the weighted deviations, by zones, to zone-specific quality measures or setting values to influence the ink feed control elements of the printing machine.
Claim 17
Dependent Claim
180 words
Apparatus for evaluating printing quality and/or regulating ink feed controls in an offset printing machine, having a photoelectric scanning device (3) for the printed products (4) while the printing machine (1) is running and also having an electronic system (5) for controlling the scanning device (3) and for evaluating the measured data produced by the scanning device, taking into account a quality measure or setting values for the ink feed control elements (2) of the printing machine, characterized in that the electronic system (5) has means (51) for converting the reflectances detected by the scanning device into surface coverages, means (53) for determining weighting factors by means of the calculated surface coverages, means (56) for determining the deviations of the surface coverages from printed products to be examined with respect to the surface coverages of a reference printed product, means (54, 55, 57-59) for the weighting of these deviations with the weighting factors and means for summing the weighted deviations, by zones, to zone-specific quality measures or setting values to influence the ink feed control elements of the printing machine.
Claim 18
Dependent Claim
39 words
Apparatus according to Claim 15, characterized in that it has a device (6) cooperating with the electronic system (5) for photoelectrically scanning the printing plates by areas, and for determining surface coverages, in image elements, of these printing plates.
Claim 19
Dependent Claim
31 words
Offset printing machine having an automatic regulating device for its ink feed control elements, characterized in that the regulating device is constructed in accordance with one of Claims 15 to 16.
References Cited (Backward Citations)
No citation records indexed.
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