| 摘要 |
<P>PROBLEM TO BE SOLVED: To determine a pattern area ratio for each of split regions in a stage wherein a planographic printing original plate is heated so as to form an image, and to adjust the quantity of ink supplied from a printing machine, for each of the split regions, according to the pattern area ratio. <P>SOLUTION: In a planographic printing method, the image is formed in the planographic printing original plate with an image forming layer by infrared laser exposure based on digital data on a pattern, and printing is done by directly mounting the planographic printing original plate on the printing machine without development processing. The planographic printing method comprises: a process for exposing the image of the planographic printing original plate, wherein an optical density at a wavelength of 400-800 nm is changed by 0.2 or more, to an infrared laser; a process wherein the image area ratio is measured by reading a difference between the optical densities by means of light with a wavelength for each of the regions split depending on the number of ink control keys of the printing machine; a process wherein the quantity of the supplied ink is controlled by setting the degree of opening for each of the ink control keys of the printing machine according to the pattern area ratio; and a process wherein the printing is done by directly mounting the planographic printing original plate on the printing machine without the development processing. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
