Patent ID: 8746827

Claim:
A printing apparatus including a drop emitting device comprising: a drop generator; a controller emitting a drop firing waveform applied to the drop generator during a drop firing interval; the drop firing waveform including in sequence a pulse of a first polarity, a first pulse of a second polarity, a delay interval, and a second pulse of the second polarity, wherein the second polarity is opposite the first polarity; wherein the second pulse of the second polarity includes a first segment increasing in the direction of the second polarity, a first substantially constant segment, a high frequency sub-pulse having a frequency that is greater than about 75 KHz, a second substantially constant segment and a segment decreasing in the direction of the second polarity wherein the sub-pulse includes in series a segment decreasing in the direction of the second polarity, a segment increasing in the direction of the second polarity and a segment decreasing in the direction of the second polarity.