| 摘要 |
PROBLEM TO BE SOLVED: To provide a wetting water supplier and a printing device, which are capable of supplying wetting water while changing the wetting water in accordance with an image on a printing plate. SOLUTION: A wetting water supplying unit 11 is constituted of an ink jet head 20 consisting of the group of a plurality of discharging elements arranged along the axial line of the plate cylinder 1. In this printing device, image data for supplying the wetting water is operated based on the image data corresponding to the image on the printing plate. The image data for supplying wetting water are obtained by converting the concentration of ink image simultaneously with the converting of resolution of the image data and the data show the image concentration of the wetting water. Respective image concentrations of image data for supplying the wetting water are changed into area gradation by error dispersion method or dither method whereby the wetting water discharging position of the discharging elements on the printing plate are determined. In this wetting water supplying unit 11, the amount of wetting water can be changed with respect to the axial direction of the plate cylinder or the rotating direction of the plate cylinder whereby the optimum amount of wetting water can be retained in each area of surface of the printing plate and, as a result, the quality of the printing can be improved. |
