MEMS sensor driving device, MEMS sensor driving method, and active sensor using MEMS

• US 7,451,647 B2
• Filed: 10/09/2006
• Issued: 11/18/2008
• Est. Priority Date: 10/21/2005
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Nagata, Masaya, Fukumoto, Koji, Matsuhisa, Kazuhiro, Yasui, Atsuhito
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US11/539,743
• Publication Number:
  US 20070089512A1
• Time in Patent Office: 771 Days
• Field of Search: 735/143.2, 735/141.7, 735/141.8, 735/142.1, 735/142.2, 735/142.3, 735/142.4, 735/141.6, 735/142.9, 735/041.2, 735/041.4
• US Class Current: 73/514.18
• CPC Class Codes: G01C 19/56 Turn-sensitive devices using vibrating masses, e.g. vibratory angular rate sensors based on Coriolis forces
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0888 for indicating angular acceleration

Abstract

A MEMS sensor driving device drives a MEMS sensor including a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, and an oscillator which is supported by another end of the elastic member in a suspended state over the surface of the substrate and which is displaceable for the substrate. The MEMS sensor driving device includes a detecting unit for detecting an oscillation of the oscillator, and a feedback unit for amplifying a signal representing the oscillation detected by the detecting unit and inputting the amplified signal as a driving signal to the MEMS sensor.

Claims

1. A microelectromechanical system sensor driving device for driving a microelectromechanical system sensor including an oscillator the microelectromechanical system sensor driving device comprising:

a detecting unit for detecting an oscillation of the oscillator; and

a feedback unit for amplifying a signal representing the oscillation detected by the detecting unit and inputting the amplified signal as a driving signal to the microelectromechanical system sensor,

wherein,

the microelectromechanical system sensor includes a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, such that the oscillator is supported by another end of the elastic member in a suspended state over the surface of the substrate and displaceable relatively to the substrate, and a driving electrode connected to the supporter via the elastic member for electromagnetically driving the oscillator.

2. The microelectromechanical system sensor driving device according to claim 1, wherein the feedback unit includes:

a noise eliminating unit for eliminating a noise component included in the amplified signal; and

a phase adjusting unit for performing phase adjustment on a signal output from the noise eliminating unit.

3. The microelectromechanical system sensor driving device according to claim 1, wherein the feedback unit includes an amplitude adjusting unit for performing amplitude adjustment on the amplified signal.

4. The microelectromechanical system sensor driving device according to claim 1, further comprising:

a phase-locked loop circuit whose operation is initiated on the basis of the signal representing the oscillation detected by the detecting unit in a state when driven by the feedback unit allows the microelectromechanical system sensor to self-oscillate,

wherein,

when the phase-locked loop circuit is locked, driving of the microelectromechanical system sensor is switched from driven by the feedback unit to driven by the phase-locked loop circuit.

5. A microelectromechanical system sensor driving method for driving a microelectromechanical system sensor including an oscillator, the microelectromechanical system sensor driving method comprising the steps of:

detecting an oscillation of the oscillator; and

amplifying a signal representing the detected oscillation and inputting the amplified signal as a driving signal to the microelectromechanical system sensors,

wherein

the microelectromechanical system sensor includes a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, such that the oscillator is supported by another end of the elastic member in a suspended state over the surface of the substrate and displaceable relatively to the substrate, and a driving electrode connected to the supporter via the elastic member for electromagnetically driving the oscillator.

6. An active sensor comprising:

a microelectromechanical system sensor including a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, an oscillator supported by another end of the elastic member in a suspended state over the surface of the substrate, the oscillator being displaceable for the substrate, and a driving electrode connected to the supporter via the elastic member for electromagnetically driving the oscillator; and

a driving unit for detecting an oscillation of the oscillator, amplifying a signal representing the detected oscillation, and inputting the amplified signal as a driving signal to the microelectromechanical system sensor.

7. A microelectromechanical system sensor driving device for driving a microelectromechanical system sensor including an oscillator, the microelectromechanical system sensor driving device comprising:

a detecting unit detecting an oscillation of the oscillator; and

a feedback unit performing amplification of a signal representing the oscillation detected by the detecting unit and input of the amplified signal as a driving signal to the microelectromechanical system sensors,

wherein

the microelectromechanical system sensor includes a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, such that the oscillator is supported by another end of the elastic member in a suspended state over the surface of the substrate and displaceable relatively to the substrate, and a driving electrode connected to the supporter via the elastic member for electromagnetically driving the oscillator.

8. An active sensor comprising:

a microelectromechanical system sensor including a supporter provided on a surface of a substrate, an elastic member having one end connected to the supporter, an oscillator supported by another end of the elastic member in a suspended state over the surface of the substrate, the oscillator being displaceable for the substrate, and a driving electrode connected to the supporter via the elastic member for electromagnetically driving the oscillator; and

a driving unit performing detection of an oscillation of the oscillator, amplification of a signal representing the detected oscillation, and input of the amplified signal as a driving signal to the microelectromechanical system sensor.