Patent attributes
The ink jet printing apparatus forms an image on a print medium with the following two operations. The printing operation makes a print head perform scan motions in a predetermined direction on the print medium, the print head having an array of nozzle rows corresponding to the required number of ink colors, each scan motion involving the ink being ejected from nozzles onto the print medium. The print medium feeding operation moves the print medium and the print head relative to each other a predetermined amount in a direction different from a direction of the scan motion between the scan motions. In a print mode using a small number of ink colors employed for printing, unidirectional printing is performed such that the nozzle row of a black ink to be ejected reaches a print start position when amplitude of vibration of the print head is a predetermined amount or less.
