| 摘要 |
PROBLEM TO BE SOLVED: To provide a plate-making device for performing offset printing which does not require an alkaline developer, then produces a high quality printed image whose image area and non-image area are sharply identifiable, and can use a master plate for printing repeatedly. SOLUTION: A master plate for printing 3 with a thin coat composed mainly of titanium oxide, zinc oxide or the like formed on the surface is exposed to an active light in the form of an image by an active light emission part 5 with a lith film 9 brought into close contact with the master plate 3 in the plate-making device 1. Consequently, a non-image area which is hydrophilic and an image area which is lipophilic, to which the active light is emitted, are formed on the master plate 3. The master plate 3 is conveyed to a printing device 2, then an ink and a moistening water are supplied to the master plate 3 from an ink/moistening water supply part 16 and thus are borne by the master plate 3 to perform a printing operation. After its completion, the residual ink is cleaned off the master plate 3 using an ink cleaning part 17, then the master plate 3 is conveyed to the device 1, and is restored to its original state by heating the master plate 3 by the heating part 6 of the device 1. Thus it is possible to use the master plate 3 repeatedly to perform the printing operation. |
