Patent ID: 6761423
Filing Date: 2004-07-13
Classification: B41J

Abstract:
An ink-jet printing apparatus comprising:a plurality of nozzles configured to eject ink, the nozzles being grouped into two or more nozzle groups; pressure chambers, each being provided to one of the nozzles; ink-ejection energy generators, each being provided for one of the pressure chambers; and a vibration controller configured to supply a non-ejecting vibration signal to the ink-ejection energy generators of each nozzle group at a different timing, the non-ejecting vibration signal causing the corresponding ink-ejection energy generator to produce energy so as not to cause the ink to eject from the nozzle, but cause a liquid surface of the ink to slightly vibrate in the associated nozzle, wherein the vibration controller has a reference frequency for causing the slight vibration at the liquid surface of the ink, and wherein the vibration controller includes a frequency-dividing vibration unit configured to divide the reference frequency according to the number of the nozzle groups and to drive the ink-ejection energy generators in the respective nozzle groups, while shifting a phase of the non-ejecting vibration signal for each nozzle group.