A plurality of capacitors each of which has a first and a second electrode. A plurality of first switches is connected between the first electrodes of the plurality of capacitors and a first power supply. A plurality of second switches is connected between the second electrodes of the plurality of capacitors and a second power supply. A plurality of resistances each of which is connected between the first electrode of one of the plurality of capacitors and the second electrode of another capacitor and which connect the plurality of capacitors in series, a voltage for driving an actuator being output from the last stage of the plurality of capacitors connected in series.