Patent ID: 6490924
Filing Date: 2002-12-10
Classification: G01C

Abstract:
An actuator for an oscillator comprising:an electrostatic driven oscillator; an oscillator driving means for oscillating the electrostatic driven oscillator by outputting a drive signal thereto; a displacement detecting means for detecting a displacement according to an oscillation of the electrostatic driven oscillator as a displacement signal; and an amplitude adjusting means for controlling the generation of the drive signal outputted from the oscillator driving means to maintain the constancy of an oscillation amplitude of the electrostatic driven oscillator based on the detected displacement signal; wherein the amplitude adjusting means includes an alternating voltage component generating means for generating an alternating voltage component of the drive signal having a constant amplitude or an amplitude proportional to the oscillation amplitude and a direct-current voltage component generating means for generating a direct current component of the drive signal controlled to be increased or decreased based on the detected displacement signal; wherein an oscillation driving force of the electrostatic driven oscillator is controlled based on the drive signal including said alternating voltage component and the direct-current voltage component to maintain the constancy of the oscillation amplitude of the electrostatic driven oscillator.