This lens drive device is provided with: a first movable part; a second movable part; a first drive part; and a second drive part. The first drive part and the second drive part respectively have a first ultrasonic motor and a second ultrasonic motor. The first ultrasonic motor and the second ultrasonic motor are arranged on sides opposite to each other with respect an optical axis, and independently drive the first movable part and the second movable part in the optical axis direction.

An optical element driving mechanism is provided and includes a fixed assembly, a movable assembly, and a driving assembly. The movable assembly is configured to be connected to an optical element and is movable relative to the fixed assembly. The driving assembly is configured to drive the movable assembly to move along a first axis relative to the fixed assembly.

A piezo actuator system includes a piezo actuator; and a driving circuit configured to apply a pulse width modulation (PWM) voltage waveform to the piezo actuator. An envelope of the PWM voltage waveform includes a first period in which a first voltage rising with a first slope is applied, a second period in which a second voltage rising with a second slope is applied, and a third period in which a third voltage rising with a third slope is applied. The third slope is greater than the second slope.

A displacement magnifying mechanism, polishing device, actuator, electronic component processing apparatus, dispenser, and air valve which can easily control a drive system. The displacement magnifying mechanism includes a base; a piezoelectric element of which an end is attached to a mounting surface of the base, the piezoelectric element extending along a first longitudinal direction; a support member of which an end is attached to the mounting surface side by side with the piezoelectric element, the support member extending along a second longitudinal direction which intersects with the first longitudinal direction; an operating portion attached to each of other ends of the piezoelectric element and the support member to allow the operating portion to be displaced, in response to an expansion/contraction of the piezoelectric element, along a displacement direction; and a compression member attached to the base and the operating portion so as to compress the piezoelectric element.