Patent ID: 6497147
Filing Date: 2002-12-24
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; an amplitude adjusting means for controlling the generation of the drive signal outputted from the oscillator driving means based on the detected displacement signal; the amplitude adjusting means including an alternating voltage component generating means for generating an alternating voltage component of the drive signal having a first amplitude during normal operation and for generating the alternating voltage component of the drive signal having a second amplitude which is larger than the first amplitude during a starting operation and a direct-current voltage component generating means for generating a direct current voltage component of the drive signal controlled to be increased or decreased based on the detected displacement signal; wherein an oscillation amplitude of the electrostatic driven oscillator is adjusted to be constant by controlling an oscillation force of the electrostatic driven oscillator based on an incorporated signal consisting of a direct-current voltage component and an alternating voltage component having a first amplitude at the normal operation; and the oscillation amplitude of the electrostatic driven oscillator is increased by driving a larger oscillation drive force to the electrostatic driven oscillator based on the incorporated signal consisting of the direct-current voltage component and the alternating voltage component having a second amplitude at the starting operation.