Patent ID: 6929340

Claim:
A drive circuit for an ink jet head having nozzles, pressure generating chambers filled with ink to be discharged from said nozzles, and piezoelectric actuators corresponding to respective pressure generating chambers, said ink jet head discharging ink droplets from said nozzles by changing volumes of said pressure generating chambers in response to a drive waveform signal applied to said piezoelectric actuators, said drive circuit comprising: a waveform generator generating said drive waveform signal; a power amplifier amplifying said drive waveform signal supplied to a first input of said power amplifier and outputting said drive waveform signal to said piezoelectric actuators via a first electrical connection having a first end coupled to the power amplifier and a second end coupled to the piezoelectric actuator; and a feedback loop having a resistor connected with a capacitor in parallel and feeding a terminal voltage at the second end of the first electrical connection applied to said piezoelectric actuators back to a second input of said power amplifier wherein the terminal voltage is fed via the resistor, wherein a first end of the feedback loop is connected to the second end of the first flexible cable.