Patent ID: 7477420
Filing Date: 2009-01-13
Classification: B41F,B41P

Abstract:
1. A process for measuring and controlling a color value of one or more colored image portions which are printed on a planar substrate in a plurality of ink zones that extend across a width of the substrate, each colored image portion comprising one or more colors, wherein each color has a pure color value, the process comprising: (a) providing one or more colored image portions which are printed on a planar substrate with a quantity of ink in a plurality of ink zones that extend across a width of the substrate, each colored image portion comprising one or more colors, wherein each color has a pure color value; (b) providing a memory which contains pure color value information in digital form for each color; (c) providing a pixellated digital representation of said one or more colored image portions, said pixellated digital representation being divided into a plurality of digital paths corresponding to each of said ink zones, each digital path comprising a plurality of digital zones, and said pixellated digital representation being further divided into one or more color layers, each color layer corresponding to one of said one or more colors, and wherein said pixellated digital representation comprises target color values that correspond to the quantity of ink required to reproduce the one or more colored image portions for each color within each ink zone on the substrate; (d) analyzing each of the color layers within each of the digital paths to determine a maximum pixel population area for each color within each of said digital paths, the maximum pixel population area having position coordinates and comprising a location within the colored image portion within the digital zone of a digital path having the target color value that is the closest target color value to the pure color value for its corresponding color within its digital path, and storing the maximum pixel population area position coordinates and its color value in the memory; (e) comparing and determining any difference between the target color value of said maximum pixel population area and the corresponding pure color value for each color, and storing said difference in the memory; (f) providing at least one imaging assembly, wherein the imaging assembly is capable of capturing digital representations of said one or more colored image portions; (g) controlling the positioning and linear movement of said imaging assembly across the planar substrate; (h) selecting and acquiring one or more digital images with the imaging assembly of said one or more colored image portions on the substrate at the maximum pixel population area location for at least one of said colors in at least one of said ink zones, thereby producing the digital image of the substrate at the maximum pixel population area; said digital image of the substrate at the maximum pixel population area having an actual color value for said at least one color in said at least one of said ink zones; (i) analyzing the digital image of the substrate at the maximum pixel population area and measuring the actual color value for said at least one color; (j) comparing and determining any difference between the actual color value and the pure color value, and storing said difference in the memory; and (k) optionally adjusting the ink quantity on the substrate in the corresponding ink zone such that the difference between the actual color value and the pure color value is equivalent to the difference between said target color value and said pure color value determined in (e).