Electrostatic actuator and method of driving the same

Abstract

An electrostatic actuator includes a stator having a circular surface carrying a plurality of drive electrodes, a rotor arranged opposite to the surface of the stator and a drive circuit for applying a drive voltage to the drive electrodes. Each of the drive electrodes has an arcuate profile extending from the center toward the outer periphery of the circular surface. The rotor can be driven to rotate in either direction of rotation by changing the mode of applying voltages to the drive electrodes. The rotor is floated above the stator by dynamic pressure generated by an oscillator, typically a piezoelectric element, provided under the stator. The distance between the rotor and the stator can be adjusted by controlling drive voltages applied to the oscillator.

Dependencies are inferred from the claim text.