Patent ID: 7852127

Claim:
A driving circuit that drives a capacitive load, comprising: a drive signal generator that generates a drive signal that drives the capacitive load via a transistor pair in response to an analog signal; a power-source voltage generator that generates a high-voltage power-source voltage and a low-voltage power-source voltage and that supplies the high-voltage power-source voltage and the low-voltage power-source voltage respectively to collectors of the transistors of the transistor pair via a high-voltage output terminal and a low-voltage output terminal, the power-source voltage generator including multiple power sources connected in parallel, a backcurrent prevention diode connected between the adjacent power sources, and a first switch unit that connects the adjacent power sources in series under the on-off control of a controller each time the drive signal rises above a predetermined threshold value or falls below a predetermined threshold value; a voltage controlling capacitor that is connected to the low-voltage output terminal of the power source; and a power recovery unit that includes a second switch unit that recovers a charge accumulated in the voltage controlling capacitor back to the power source via the high-voltage output terminal.