| 摘要 |
<p>It is made possible to non-mechanically adjust and eliminate a mutual deviation between images printed by a plurality of printing units in a digital sheet-fed printing machine using a plurality of transport cylinders. A digital sheet-fed printing method is disclosed which comprises: providing one cycle of printing to print on a series of sheets of paper whose number is equal to the least common multiple of respective numbers of allocated positions on adjacent ones of the transport cylinders; for each sheet of paper in the series to be printed in the one cycle of printing, producing a reference signal on the basis of which an image in each color is printed on the sheet of paper with each printing unit, timed to its passage through the printing unit, under control by a printing control means; in a first of such cycles of printing, detecting with an image detection sensor means a mutual out of register between images in different colors printed on each sheet of paper in the series, furnishing the printing control means with a detection signal for each sheet of paper from the image detection sensor means, and correcting the timing at which each image is printed on each sheet of paper in one cycle of printing by the printing control means and on the basis of such detection signals so that timings to print the images in different colors on each sheet of paper may be coincided with one another; and in each subsequent printing cycle, printing images in the different colors on each sheet of paper at a printing timing as corrected as aforesaid.</p> |
