Patent ID: 8398194

Claim:
A power amplifier comprising: a modulator that pulse-modulates a drive waveform signal serving as a reference of a drive signal applied to an actuator to output at least two post-modulated signals; a digital power amplifier that amplifies the at least two post-modulated signals to output multi-value amplified digital signals, the digital power amplifier having a plurality of digital power amplifier stages each including a pair of push-pull switching elements; and a low pass filter that filters the amplified digital signals and outputs the drive signal, wherein the modulator includes a control section including a control section that switches between a first state where the modulator outputs a first post-modulated signal of the at least two post-modulated signals to two or more of the digital power amplifier stages, a second state where the modulator outputs a second post-modulated signal of the at least two post-modulated signals to two or more of the digital power amplifier stages and a third state where both of the at least two post-modulated signals are simultaneously connected to one of the digital power amplifier stages.