Patent ID: 8657401
Filing Date: 2014-02-25
Classification: B41J

Abstract:
1. An image forming apparatus comprising: a printing head unit including: a driving waveform generator to generate and output a driving waveform having at least four driving pulses per driving cycle arranged in chronological order; and a selector to select and apply at least one of the multiple driving pulses included in the driving waveform outputted from the driving waveform generator to the pressure generator to cause the printing head unit to selectively discharge liquid droplets of at least three different sizes, wherein three or more driving pulses including a final driving pulse included in the at least four driving pulses at the end of the driving waveform discharges a biggest liquid droplet, and a micro-driving pulse included therein discharges a smallest droplet, wherein the micro-driving pulse is outputted within a time period of from about 2×Tc to about 4×Tc after the driving waveform starts being outputted when Tc represents a natural vibration period of the liquid chambers of the printing head.