Pressure sensor and pressure detection device

Patent metadata

Field	Value
Publication number	US-9915576-B2
Application number	US-201415031574-A
Country	US
Kind code	B2
Filing date	Sep 29, 2014
Priority date	Oct 25, 2013
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A pressure sensor includes: a fixed part; a ring-like oscillator that is supported on the fixed part by a plurality of support beams; a plurality of electrodes that are provided on the fixed part and arranged in an oscillating direction of the ring-like oscillator with a gap; electret films that are formed on either one of opposite surfaces of the ring-like oscillator and the electrodes.

First claim

The invention claimed is:

1. A pressure sensor comprising:
a fixed part;
a ring-like oscillator that is supported on the fixed part by a plurality of support beams;
a plurality of electrodes that are provided on the fixed part and arranged in an oscillating direction of the ring-like oscillator with a gap; and
electret films that are formed on either one of opposite surfaces of the ring-like oscillator and the electrodes.

2. The pressure sensor according to claim 1 , wherein:
the ring-like oscillator has an annular shape.

3. The pressure sensor according to claim 1 , wherein:
the support beams support parts where nodes of oscillation of the ring-like oscillator appear; and
the plurality of electrodes are arranged to be opposite to parts that antinodes of oscillation of the ring-like oscillator appear.

4. A pressure detection device comprising:
the pressure sensor according claim 1 , wherein:
the plurality of electrodes provided in the pressure sensor include two or more driving electrodes and one or more detecting electrode;
there is provided a power source that applies an alternating current voltage to the driving electrodes; and
there is provided a pressure calculating unit that detects a voltage signal due to oscillation of the ring-like oscillator generated in the detecting electrode and outputs pressure information based on the voltage signal.

5. The pressure detection device according to claim 4 , wherein:
the power source applies an alternating current voltage in a predetermined frequency range to the driving electrodes; and
the pressure calculating unit outputs a difference between a level of the voltage signal detected in a resonance state and a level of the voltage signal detected in a non-resonance state as the pressure information.

6. A pressure detection device comprising:
the pressure sensor according to claim 1 ;
a power source that applies an alternating current voltage to the plurality of electrodes; and
a pressure calculating unit that detects an admittance of an electromechanically coupled system including the pressure sensor to which the alternating current voltage is applied and outputs pressure information based on a value of the detected admittance.

7. The pressure sensor according to claim 2 , wherein:
the support beams support parts where nodes of oscillation of the ring-like oscillator appear; and
the plurality of electrodes are arranged to be opposite to parts that antinodes of oscillation of the ring-like oscillator appear.

8. A pressure detection device comprising:
the pressure sensor according to claim 2 , wherein:
the plurality of electrodes provided in the pressure sensor include two or more driving electrodes and one or more detecting electrode;
there is provided a power source that applies an alternating current voltage to the driving electrodes; and
there is provided a pressure calculating unit that detects a voltage signal due to oscillation of the ring-like oscillator generated in the detecting electrode and outputs pressure information based on the voltage signal.

9. A pressure detection device comprising:
the pressure sensor according to claim 3 , wherein:
the plurality of electrodes provided in the pressure sensor include two or more driving electrodes and one or more detecting electrode;
there is provided a power source that applies an alternating current voltage to the driving electrodes; and
there is provided a pressure calculating unit that detects a voltage signal due to oscillation of the ring-like oscillator generated in the detecting electrode and outputs pressure information based on the voltage signal.

10. A pressure detection device comprising:
the pressure sensor according to claim 7 , wherein:
the plurality of electrodes provided in the pressure sensor include two or more driving electrodes and one or more detecting electrode;
there is provided a power source that applies an alternating current voltage to the driving electrodes; and
there is provided a pressure calculating unit that detects a voltage signal due to oscillation of the ring-like oscillator generated in the detecting electrode and outputs pressure information based on the voltage signal.

11. The pressure detection device according to claim 8 , wherein:
the power source applies an alternating current voltage in a predetermined frequency range to the driving electrodes; and
the pressure calculating unit outputs a difference between a level of the voltage signal detected in a resonance state and a level of the voltage signal detected in a non-resonance state as the pressure information.

12. The pressure detection device according to claim 9 , wherein:
the power source applies an alternating current voltage in a predetermined frequency range to the driving electrodes; and
the pressure calculating unit outputs a difference between a level of the voltage signal detected in a resonance state and a level of the voltage signal detected in a non-resonance state as the pressure information.

13. The pressure detection device according to claim 10 , wherein:
the power source applies an alternating current voltage in a predetermined frequency range to the driving electrodes; and
the pressure calculating unit outputs a difference between a level of the voltage signal detected in a resonance state and a level of the voltage signal detected in a non-resonance state as the pressure information.

14. A pressure detection device comprising:
the pressure sensor according to claim 2 ;
a power source that applies an alternating current voltage to the plurality of electrodes; and
a pressure calculating unit that detects an admittance of an electromechanically coupled system including the pressure sensor to which the alternating current voltage is applied and outputs pressure information based on a value of the detected admittance.

15. A pressure detection device comprising:
the pressure sensor according to claim 3 ;
a power source that applies an alternating current voltage to the plurality of electrodes; and
a pressure calculating unit that detects an admittance of an electromechanically coupled system including the pressure sensor to which the alternating current voltage is applied and outputs pressure information based on a value of the detected admittance.

16. A pressure detection device comprising:
the pressure sensor according to claim 7 ;
a power source that applies an alternating current voltage to the plurality of electrodes; and
a pressure calculating unit that detects an admittance of an electromechanically coupled system including the pressure sensor to which the alternating current voltage is applied and outputs pressure information based on a value of the detected admittance.

Assignees

• Univ Tokyo
• Kk saginomiya seisakusho

Inventors

• Fujita Hiroyuki
• Hashiguchi Gen
• Mitsuya Hiroyuki
• Ashizawa Hisayuki

Classifications

• G01L9/0016 Primary

  of a diaphragm · CPC title