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AssigneeKba-Notasys SA
InventorJacques PERRIER
Estimating the term…
There is described a process of measuring print-to-print register of a multicolour print (A-D) provided in an effective printed area (EPA) of the surface of printed material, which multicolour print (A-D) is formed on the printed material by means of one or more printing presses and includes at least a first pattern (A) and a second pattern (B) distinguishable from the first pattern (A), the effective printed area (EPA) being provided with a matrix arrangement of individual imprints (P) which are each provided with the multicolour print (A-D) and are repeated over the surface of the effective printed area (EPA) along a pattern of rows and columns. Measurement of an actual print-to-print register between the first and second patterns (A, B), as reflected on the printed material, is derived from processing and finding a correspondence between (i) at least one sample image (SIA, SIB) of the printed material covering at least a portion of the first and second patterns (A, B), and (ii) at least one corresponding reference image (RIA, RIB) generated using prepress design data of the first and second patterns (A, B). Furthermore, the process is repeated for multiple ones of the individual imprints (P) so as to derive a set of multiple measurements of the actual print-to-print register between the first and second patterns (A, B) at various imprint locations over the effective printed area (EPA), which set of multiple measurements is mapped into a corresponding print-to-print register map (MB-A, MC-A, MD-A, . . . ) that is representative of print-to-print register deviations at the various imprint locations. Also described is a measuring device for carrying out this process and a process of measuring and correcting print-to-print register of a multicolour print.
A process of measuring print-to-print register of a multicolour print (A-D) provided in an effective printed area (EPA) of the surface of printed material, which multicolour print (A-D) is formed on the printed material by means of one or more printing presses and includes at least a first pattern (A) and a second pattern (B) distinguishable from the first pattern (A),
The process according to any one of the preceding claims, wherein the correspondence between the at least one sample image (SIA, SIB) and the at least one reference image (RIA, RIB) is found by performing a cross-correlation between the at least one sample image (SIA, SIB) and the at least one reference image (RIA, RIB), which cross-correlation includes finding an optimum of a correlation function between the at least one sample image (SIA, SIB) and the at least one reference image (RIA, RIB).
The process according to any one of the preceding claims, wherein the process is repeated for each one of the individual imprints (P) so as to derive at least one measurement of the actual print-to-print register between the first and second patterns (A, B) at each imprint location.
The process according to any one of the preceding claims, wherein the multicolour print (A-D) comprises more than two patterns and wherein the process is carried out in order to measure print-to-print register between multiple pairs of patterns (A-B, A-C, A-D, . . . ).
A process of measuring and correcting print-to-print register of a multicolour print (A-D) provided in an effective printed area (EPA) of the surface of printed material, which multicolour print (A-D) is formed on the printed material by means of one or more printing presses and includes at least a first pattern (A) and a second pattern (B) distinguishable from the first pattern (A),
The process according to any one of the preceding claims, wherein the multicolour print (A-D) is formed on the printed material by means of a multicolour printing press comprising multiple printing plates (PP).
Dependencies are inferred from the claim text.