Printing apparatus for making a lithographic printing plate involving on press development

摘要

The present invention discloses a method for preparing lithographic printing plates by the following steps: (i) mounting to the print cylinder of a printing apparatus comprising at least one print station including: a print cylinder; means for mounting to the print cylinder an imaging element; at least one laser or L.E.D device; means for guiding output of said laser or L.E.D. device to focus on the imaging elements surface; means for moving the guiding means and support means relative to one another to effect a scan of the imaging elements surface by the output of said laser or L.E.D. device an imaging element comprising (1) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles dispersed in a hydrophilic binder and (2) a compound capable of converting light to heat, said compound being comprised in said image forming layer or a layer adjacent thereto; (ii)information-wise exposing by means of said laser or L.E.D. device said imaging element; (iii) applying by means of a means for supplying a dampening liquid to said print cylinder a dampening liquid to said print cylinder; (iv) after, before or simultaneously with step (iii) applying by means of a means for supplying ink to said print cylinder ink to said print cylinder; (v) transferribg a receiving element to said print station by means of a means for transferring a receiving element to said print station; (vi) transferring ink from said print cylinder to said receiving element by means for transferring ink from said print cylinder to said receiving element.