COLOR CONTROL OF A WEB PRINTING PRESS UTILIZING INTRA-IMAGE COLOR MEASUREMENTS

摘要

Accurate on-line color control for a printing press can be obtained using intra-image color control. A concurrent spectrophotometer and imaging system (203, 310) can capture spectral reflectance data from predetermined measurement areas for each ink key zone of the press. The spectral reflectance data (204) can be compared to target reflectance values in the same standard color space, and a determination can be made as to whether the differences between the measured and target values exceed predetermined tolerances (208). If the differences exceed these tolerances (208), a necessary adjustment to the appropriate ink key can be calculated to bring the color differences back to within tolerance. This approach is particularly beneficial in web offset printing, where the printed image is constantly moving and the press conditions are particularly variable.