Vibratory structure, method for controlling natural frequency thereof, and actuator, sensor, accelerator, gyroscope and gyroscope natural frequency controlling method using vibratory structure

A method for controlling the natural frequency of a vibratory structure, said vibratory structure comprising:

• at least one elastic member supported by a first support end;
• an inertial object which vibrates by the elastic force of said elastic member;
• a moving electrode coupled to said inertial object;
• at least one effective stiffness controlling electrode supported by a second support end;
• and a power supplier for applying a voltage to generate an electric force between said moving electrode and said effective stiffness controlling electrode,
• wherein the effective stiffness and natural frequency of said vibratory structure are controlled by adjusting said voltage.

An actuator including at least one vibratory structure, said vibratory structure comprising:

• at least one elastic member supported by a first support end;
• an inertial object which vibrates by the elastic force of said elastic member;
• a moving electrode coupled to said inertial object;
• at least one effective stiffness controlling electrode supported by a second support end;
• and a power supplier for applying a voltage to generate an electric force between said moving electrode and said effective stiffness controlling electrode,
• wherein the effective stiffness and natural frequency of said vibratory structure are controlled by adjusting said voltage.

A gyroscope comprising:

• a substrate having a plane of a first axis and a second axis;
• a support end supported by said substrate;
• an elastic member supported by said support and extended in said first- and second-axis directions;
• an inertial object for vibrating in said first axis direction and a third axis direction;
• a finger electrode formed integrally into said inertial object;
• a driving unit having a finger to be engaged with said finger electrode of said inertial object, for applying an electric force to said inertial object in said first axis direction;
• detector means for detecting vibration of said inertial object in said first- and third-axis directions;
• an effective stiffness controlling electrode disposed to face said inertial object on said substrate to control the third-axis directional natural frequency of said inertial object;
• and
• a power supplier for applying a voltage to said effective stiffness controlling electrode and said finger electrode of said inertial object.

A method for controlling the natural frequency of a gyroscope comprising:

• providing a substrate having a plane of a first axis and a second axis;
• providing a support end supported by said substrate;
• providing an elastic member supported by said support and extended in said first and second axis directions;
• providing an inertial object for vibrating in said first axis direction and a third direction;
• providing a finger electrode formed integrally into said inertial object;
• engaging a driving unit having a finger with said finger electrode of said inertial object for applying an electric force to said inertial object in said first axis direction;
• detecting vibrations of said inertial object in said first and third axis directions;
• controlling the third axis directional natural frequency of said inertial object using an effective stiffness controlling electrode disposed to face said inertial object on said substrate;
• and
• applying a voltage to said effective stiffness controlling electrode and said finger electrode of said inertial object.