Patent ID: 8657393

Claim:
An ink jet printing apparatus comprising: a print head configured to eject ink to a print medium; a carriage configured to allow the print head to perform scanning guided by a guide shaft in a direction crossing a direction in which the print medium is conveyed; a platen having a suction port in which a negative pressure is supplied to suck the print medium onto the platen; a fan configured to generate the negative pressure supplied to the suction port; a duct connected to the suction port for supplying the negative pressure generated by the fan; and a chassis on which the platen and the fan are fixed, wherein vibrations caused by the fan are transmitted to the platen via the chassis and the duct and are transmitted to the carriage via the chassis and the guide shaft, wherein the ink jet printing apparatus being controlled to perform multipass printing by reciprocating the carriage to perform N-number of repeated scans on an area of the print medium to form an image with ink ejected from the print head, and the apparatus further comprising a controller configured to set a rotational driving of the fan at a first state in a first scan and at a second state, which is different from the first state, in a second scan, and wherein the first and the second scans are included in the N-number of repeated scans, whereby possible density unevenness of the printed image which is caused by the vibrations of the fan is reduced.