Force sensing device

• US 20020178831A1
• Filed: 05/28/2002
• Published: 12/05/2002
• Est. Priority Date: 05/29/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Precision Engineering Center (Singapore) Pte Ltd. (Sony Group Corp.)
• Inventors: Takada, Akio
• Granted Patent: US 6,722,206 B2
• Time in Patent Office: Days
• US Class Current: 73/779
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 2009/02511 Vertical, i.e. perpendicular to the substrate plane
• CPC Class Codes: H03H 9/02259 Driving or detection means
• CPC Class Codes: H03H 9/2457 Clamped-free beam resonators
• CPC Class Codes: H03H 9/2463 Clamped-clamped beam resonators
• CPC Class Codes: H03H 9/462 Microelectro-mechanical filters
• CPC Class Codes: H04R 23/00 Transducers other than those covered by groups H04R9/00 - H04R21/00 diaphragms for transducers of the distributed-mode type H04R7/045

Abstract

An oscillation sensing device (1) includes a magnetized member (6) mounted on a substrate (4). A magneto-electrical material (7) is mounted on the substrate (4) such that the magneto-electrical material (7) is subjected to the magnetic field generated by the magnetized member (6). A movable member (3) is mounted for oscillation (8) in response to an oscillating force. Oscillation of the movable member (3) causes a change in the magnetic field experienced by the magneto-electrical material (7) and an electrical property of the magneto-electrical material (7) changes in response to changes in the magnetic field experienced by the magneto-electrical material (7) due to oscillation of the movable member (3).

Claims

1. A force sensing device comprises a magnetised member mounted on a substrate, a magneto-electrical material mounted on the substrate such that the magneto-electrical material is subjected to the magnetic field generated by the magnetised member, a movable member mounted for movement in response to an applied force, movement of the movable member causing a change in the magnetic field experienced by the magneto-electrical material, and an electrical property of the magneto-electrical material changing in response to changes in the magnetic field experienced by the magneto-electrical material due to movement of the movable member.

2. A device according to claim 1, wherein the magneto-electrical material comprises a magneto resistive material.

3. A device according to claim 1 or claim 2, wherein the oscillation sensing device is a micro-electro mechanical system.

4. A device according to any of the preceding claims, wherein the magnetised member and the magneto-electrical material are both in the form a thin film.

5. A device according to any of the preceding claims, wherein the magnetised member is mounted on the movable member.

6. A device according to any of claims 1 to 4, wherein the movable member comprises a soft magnetic material.

7. A device according to any of the preceding claims, wherein the movable member comprises a cantilevered member.

8. A device according to any of claims 1 to 6, wherein the movable member comprises a linearly movable member.

9. A device according to any of claims 1 to 6, wherein the movable member comprises a pivotable member.

10. A device according to any of the preceding claims, wherein the movable member is adapted for oscillating movement in response to an oscillating force.

11. A device according to claim 10, wherein the oscillating force is an acoustic force.

12. A microphone comprising a device according to claim 11.

13. A frequency filter comprising a device according to any of claims 1 to 11, wherein the movable member has a resonating frequency.