PURPOSE: To reduce power consumption considerably with comparatively a simple configuration in the output circuit applying pulse width modulation to an input signal and outputting the result to a prescribed vibration section as a drive signal.

CONSTITUTION: The output circuit 10 is provided with a polarity inversion circuit inverting the polarity of an input signal S1 and outputting the inverse of input signal, a 1st comparator circuit 12 compares the input signal S1 with an instantaneous level of the output signal from an oscillation circuit 15, and a 2nd comparator circuit 14 compares the inverse of input signal with an instantaneous level of the output signal from the oscillation circuit 15, drive signals based on the result of 1st and 2nd control circuits are fed to a drive section to form the drive signal whose duty ratio depends on the instantaneous amplitude of the input signal S1 and the output circuit able to drive the vibration section efficiently without use of undesired power through comparatively a simple configuration is realized.