| 摘要 |
PURPOSE:To improve the effect of ink presetting on printed matter where a pattern is extremely small by correcting differently the area rate of patterns measured on a 'SUMI' (Japanese ink) plate and other color plates. CONSTITUTION:A laser beam from a light source 3 is scanned by a scanner 4 on the 'SUMI' plate 1 and its reflected light is converted by a photoelectric converting element 6 into an electric signal, which is A/D-converted 7 and inputted to a CPU 8 to calculate the pattern area rate of each beam spot 5. When the 'SUMI' board 1 is the 'SUMI' plate, the pattern area rates of respective spots 5 are totalized to calculate the pattern area ratio of each ink zone 2. When this rate is about <=10%, the corrected pattern area rate of the zone 2 is set forcibly to 10%. Then when the pattern area rate of each spot is about <=10% as to a color plate, the corrected pattern area rate of each spot is set to 0%. When not, the value obtained by multiplying the measured value by about 120% is employed as the corrected pattern area rate. Thus, 'SUMI' characters are printed sharply and sufficient is supplied to a pattern part, thereby obtaining a print of good quality. |
