| 摘要 |
PROBLEM TO BE SOLVED: To form an ink film thickness distribution corresponding to the pattern of a plate-making plate of a next printing job in a short time by carrying out neither blank printing nor ink returning to a pot when a printing job is to be switched.SOLUTION: After a preceding printing job ends, a printing machine is stopped, and inking rollers 6-1 to 6-4 of an ink roller group 6 are turned off. Thereafter, the pattern area ratio of each ink fountain key is obtained by subtracting the pattern area ratio of a plate-making plate in a range corresponding to each ink fountain key of the preceding printing job from the pattern area ratio of a plate-making plate in a range corresponding to each ink fountain key of the next printing job to count the number of ink fountains the pattern area ratio difference of which is a predetermined value (positive value) or more. When the number is a predetermined number or more, the opening amount of each ink fountain key is set to an opening amount corresponding to the pattern area ratio difference of each ink fountain key, so that an ink film thickness distribution corresponding to the pattern area ratio difference of each ink fountain key is overlapped directly with the ink film thickness distribution corresponding to the pattern of a plate-making plate of the preceding printing job formed in the ink roller group 6. |
