Patent ID: 7658460

Claim:
A printing apparatus for printing an image on a print medium by mounting in the printing apparatus a plurality of ink jet print heads shifted in position from each other in a transport direction of the print medium, the print medium being transported by a transporting unit, wherein the plurality of print heads include a plurality of same color print heads capable of ejecting the same color ink, each of the plurality of same color print heads having a plurality of nozzles which are arranged in a line extending in a predetermined direction crossing the transport direction and from which the same color ink can be ejected, the plurality of print heads are divided and provided in a plurality of independent printer units which can be arranged at positions shifted from each other in the transport direction, each of the plurality of printer units comprises a memory capable of storing print data, and a printer control unit for controlling the print heads in the printer unit in which the printer control unit is comprised, the transporting unit generates a synchronization signal corresponding to a transport speed of the print medium, when a high-density print mode is set, each of the memories stores the same print data, and when the high-density print mode is set, each of the printer control units drives the print heads according to the print data stored in the memory in the printer unit, in which the printer control unit is comprised, and the synchronization signal input from the transporting unit, so that dots printed by the plurality of same color print heads overlap each other.