Patent ID: 8491074

Claim:
An ejection head driving circuit configured to supply a driving voltage waveform to an ejection head provided with ejection nozzles for ejecting fluid, the circuit comprising: a target voltage waveform output unit configured to output a target voltage waveform supply to the ejection head; a plurality of power source units configured to generate electric powers having different voltage values; a plurality of negative feedback control units configured to supply the electric powers from the respective power source units to the ejection head and perform negative feedbacks on the voltage values so as to match the voltage value applied to the ejection head with that of the target voltage waveform; and a power source connecting unit configured to select and connect one of the plurality of power source units to the ejection head based on the applied voltage value or the voltage value of the target voltage waveform, and disconnect the other power source units from the ejection head, wherein the power source units are capable of storing electric power supplied from an external power source; the power source connecting unit selects a first power source unit and a second power source unit, the first power source unit generating a higher voltage value than the voltage value applied to the ejection head or the voltage value of the target voltage waveform, the second power source unit generating a lower voltage value than the voltage value applied to the ejection head or the voltage value of the target voltage waveform; the power source connecting unit connects the first power source unit to the ejection head when the voltage value applied to the ejection head is lower than the voltage value of the target voltage waveform, and connects the second power source unit to the ejection head when the voltage value applied to the ejection head is higher than the voltage value of the target voltage waveform; and a load connected in parallel to the ejection head and capable of storing electric power supplied from an external power source; wherein the power source units are capable of storing electric power supplied from an external source; and the power source connecting unit connects the selected power source unit to the ejecting head and the load.