PURPOSE: To carry out multicolor printing without scaling up a multicolor printer by bringing the transfer protruding parts of respective rollers coated with the inks supplied from a plurality of ink sources and a plurality of the plates provided to a plate cylinder to a contact state by a synchronizing mechanism only when both of them are opposed to each other.

CONSTITUTION: Two rubber rollers 5a, 5b are arranged in the vicinity of a plate cylinder 6a and mutually separate ink fountains 2a, 2b are arranged on the upstream side of the rubber rollers 5a, 5b through intermediate rollers 4a, 4b and ducting rollers 3a, 3b. Gears 5ag, 5bg, 6ag are respectively fixed to the rotary shafts of the rubber rollers 5a, 5b and the plate cylinder 6a so as to be mutually meshed on the outer peripheral surfaces of the rotary shafts. By this constitution, the rubber rollers 5a, 5b and the plate cylinder 6a are rotated in mutually synchronous relationship and the ink transfer protruding parts 5aa, 5bb of the rubber rollers 5a, 5b come into contact with the respective corresponding plates 6aa, 6aa, 6ab, 6ab of the plate cylinder 6a certainly.