Patent ID: 8851604
Filing Date: 2014-10-07
Classification: B41J

Abstract:
1. An ink-jet recording apparatus comprising: a recording head that includes: (i) a plurality of nozzles for discharging ink droplets, (ii) a pressure chamber communicating with each of the plurality of nozzles, and (iii) a pressure generating unit which has a piezoelectric material sandwiched between two driving electrodes and which is operated by application of a driving waveform to each of the two driving electrodes based on a plurality of pieces of discharge data so as to change a capacity of the pressure chamber and to discharge ink in the pressure chamber from a corresponding nozzle, wherein the plurality of pieces of discharge data includes discharge data for discharging a relatively large ink droplet from the nozzle and discharge data for discharging a relatively small ink droplet from the nozzle; and a driving circuit that generates the driving waveform, wherein the driving waveform includes a first driving waveform composed of non-GND waveform, a second driving waveform composed of a non-GND waveform different from the first driving waveform, and a third driving waveform composed of a GND waveform, wherein a relation between a driving voltage V wherein the driving circuit selects at least the first driving waveform and the second driving waveform or only the first driving waveform at every predetermined time shorter than 1 pixel cycle in accordance with each of the plurality of pieces of discharge data, applies this to one of the two driving electrodes of the pressure generating unit and also selects and applies only the second driving waveform to the other of the two driving electrodes so as to operate the pressure generating unit by a differential waveform between the two driving electrodes.