Actuator for oscillator
First Claim
1. 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.
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Accused Products
Abstract
An actuator for an oscillator which can control the fluctuation of the oscillation of an electrostatic driven oscillator such as the detection error by controlling the fluctuation of the amount of the noise mixed into a displacement detecting signal. An actuator oscillates a drive frame and a detecting frame in the X-direction by outputting the drive signal to a drive electrode to detect the displacement of the drive frame in the X-direction as a displacement detecting signal. The actuator generates a direct-current voltage component of the drive signal increased or decreased based on the detected displacement signal and the alternating voltage component of the drive signal having a constant amplitude to maintain the oscillation amplitude of the drive frame constant.
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Citations
4 Claims
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1. An actuator for an oscillator comprising:
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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.- View Dependent Claims (2, 3, 4)
first and second drive electrodes being driven by respective drive signals whose alternating voltage components are inverted relative to each other, so that the directions of the electrostatic attraction generated between the electrostatic driven oscillator and the first and second drive electrodes are opposed to each other.
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Specification