Patent ID: 6705695
Filing Date: 2004-03-16
Classification: B41J

Abstract:
A bidirectional printer configured to form ink dots of a plurality of color inks on a printing medium along forward and reverse passes of main scanning for printing data, the printer comprising:a printing head equipped with a plurality of nozzle groups each having a plurality of nozzles that eject ink droplets of identical color; a main scanning mechanism configured to perform the main scanning by moving at least one of the printing head and the printing medium; a head driver configured to cause ejection of ink droplets from at least some of the plurality of nozzles during the main scanning; a sub-scanning mechanism configured to perform sub-scanning by moving at least one of the printing head and the printing medium; and a controller configured to control printing process; the plurality of nozzle groups including: a first type nozzle group that is used to eject ink of a first ink group including at least one ink, the first type nozzle group ejecting ink droplets along both the forward and reverse passes of the main scanning; and a second type nozzle group that is used to eject ink of a second ink group including at least one ink, the second type nozzle group ejecting ink droplets along only a selected one of the forward and reverse passes of the main scanning irrespective of a data map of the data.