Patent ID: 8807679
Filing Date: 2014-08-19
Classification: B41J,H01L

Abstract:
1. An apparatus comprising: a n-type double-diffused metal oxide semiconductor (NDMOS) transistor comprising a gate, a drain, a source, and an intrinsic diode; a piezoelectric transducer, a first surface of the piezoelectric transducer having a positive polarization and being coupled to the n-type double-diffused metal oxide semiconductor transistor; a first waveform generator coupled to a second surface of the piezoelectric transducer and configured to generate an ejector waveform to apply to the second surface of the piezoelectric transducer, where the ejector waveform includes at least a positive pulse and a negative pulse, and where an amplitude of the negative pulse is small enough to avoid ink discharge from a drop ejector driven by the piezoelectric transducer; and a second waveform generator coupled to the gate of the NDMOS transistor and configured to generate a control waveform to apply to the n-type double-diffused metal oxide semiconductor transistor to selectively actuate the piezoelectric transducer, where the piezoelectric transducer receives a negative voltage through the intrinsic diode of the NDMOS transistor whether or not a voltage of the gate is high.