Vibrator, vibration gyro using the vibrator, and electronic device using the vibration gyro

• US 6,666,096 B2
• Filed: 10/02/2002
• Issued: 12/23/2003
• Est. Priority Date: 10/02/2001
• Status: Expired due to Fees

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Mori, Akira
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): MILLER, ROSE MARY
• Application Number:
  US10/263,444
• Publication Number:
  US 20030084727A1
• Time in Patent Office: 447 Days
• Field of Search: 736/62, 735/040.2, 735/040.3, 735/040.4, 735/040.8, 735/041.2, 735/041.4, 735/041.8
• US Class Current: 73/662
• CPC Class Codes: G01C 19/5656 the devices involving a micromechanical structure

Abstract

A vibrator has a construction that allows its electrodes to be easily formed and requires a smaller number of the assembly man-hours. The vibrator includes a drive electrode and two detection electrodes that are disposed along a length direction thereof, on a planar portion provided on the surface of a vibrating member defined by piezoelectric body. These electrodes constitute interdigital electrode portions defined by mutually opposed comb electrodes which are arranged such that the direction in which the teeth thereof extend is substantially perpendicular to the length direction of the vibrating member.

Claims

1. A vibrator, comprising:

a vibrating member including a piezoelectric body and having a length direction and a width direction;

a drive electrode disposed on the surface of said vibrating member and extending along the length direction of said vibrating member; and

two detection electrodes each disposed adjacent to said drive electrode;

wherein said drive electrode and each of said detection electrodes have an interdigital electrode portion defined by mutually opposed comb electrodes which are arranged such that the direction in which the teeth thereof extend is substantially perpendicular to the length direction of said vibrating member.

2. A vibrator according to claim 1, wherein said vibrating member is polarized between said drive electrode and each of said detection electrodes.

3. A vibrator according to claim 1, wherein said vibrating member is polarized in the length direction thereof, and wherein, in said interdigital electrode portion, said drive electrode is arranged so as to be deviated in the length direction of said vibrating member with respect to each of said detection electrodes.

4. A vibrator according to claim 1, wherein said vibrating member has a planar portion extending along the length direction thereof, and wherein said drive electrode and said detection electrodes are disposed on said planar portion.

5. A vibrator according to claim 4, wherein support members are fixed to said planar portion, in the vicinity of vibration nodes of said vibrating member.

6. A vibrator according to claim 1, wherein the vibrating body has a substantially rectangular columnar shape.

7. A vibrator according to claim 1, wherein the drive electrode and each of the detection electrodes have portions where they are mutually opposed with respect to the length direction of the vibrating member, and the drive electrode and each of the detection electrodes have portions where they are mutually opposed with respect to the width direction of the vibrating member.

8. A vibrator according to claim 7, wherein the length of the portions where the drive electrode and each of the detection electrodes are mutually opposed with respect to the width direction of the vibrating member is less than that of the portions where the drive electrode and each of the detection electrodes are mutually opposed with respect to the length direction of the vibrating body.

9. A vibration gyro comprising a vibrator according to claim 1.

10. An electronic device comprising a vibration gyro according to claim 9.

11. A vibrator, comprising:

a vibrating member including a piezoelectric body and having a length direction and a width direction;

a drive electrode disposed on the surface of said vibrating member and extending along the length direction of said vibrating member;

a reference electrode disposed adjacent to said drive electrode; and

two detection electrodes each disposed adjacent to said reference electrode;

wherein said drive electrode and said reference electrode, and said reference electrode and each of said detection electrodes, have an interdigital electrode portion defined by mutually opposing comb electrodes which are arranged such that the direction in which the teeth thereof extend is substantially perpendicular to the length direction of said vibrating member;

wherein said vibrating member is polarized between said drive electrode and said reference electrode, and between said reference electrode and each of said detection electrodes; and

wherein said vibrating member has a planar portion extending along the length direction thereof, and wherein said drive electrode, said reference electrode, and said detection electrodes are disposed on said planar portion.

12. A vibrator according to claim 11, wherein support members are fixed to said planar portion, in the vicinity of vibration nodes of said vibrating member.

13. A vibrator according to claim 11, wherein the vibrating body has a substantially rectangular columnar shape.

14. A vibrator according to claim 11, wherein the drive electrode and each of the detection electrodes have portions where they are mutually opposed with respect to the length direction of the vibrating member, and the drive electrode and each of the detection electrodes have portions where they are mutually opposed with respect to the width direction of the vibrating member.

15. A vibrator according to claim 14, wherein the length of the portions where the drive electrode and each of the detection electrodes are mutually opposed with respect to the width direction of the vibrating member is less than that of the portions where the drive electrode and each of the detection electrodes are mutually opposed with respect to the length direction of the vibrating body.

16. A vibration gyro comprising a vibrator according to claim 11.

17. An electronic device comprising a vibration gyro according to claim 16.

18. A vibrator, comprising:

a vibrating member including a piezoelectric body and having a length direction and a width direction;

a drive electrode disposed on the surface of said vibrating member and extending along the length direction of said vibrating member;

a reference electrode disposed adjacent to said drive electrode; and

two detection electrodes each disposed adjacent to said reference electrode;

wherein said drive electrode and said reference electrode, and said reference electrode and each of said detection electrodes, have an interdigital electrode portion defined by mutually opposed comb electrodes which are arranged such that the direction in which the teeth thereof extend is substantially perpendicular to the length direction of said vibrating member;

wherein said vibrating member is polarized in the length direction thereof, and wherein, in said interdigital electrode portion, said drive electrode and each of said detection electrodes are arranged so as to be deviated in the length direction of said vibrating member with respect to said reference electrode.

19. A vibrator according to claim 18, wherein said vibrating member has a planar portion extending along the length direction thereof, and wherein said drive electrode, said reference electrode, and said detection electrodes are disposed on said planar portion.

20. A vibrator according to claim 19, wherein support members are fixed to said planar portion, in the vicinity of vibration nodes of said vibrating member.

21. A vibrator according to claim 18, wherein the vibrating body has a substantially rectangular columnar shape.

22. A vibrator according to claim 18, wherein the drive electrode and each of the detection electrodes have portions where they are mutually opposed with respect to the length direction of the vibrating member, and the drive electrode and each of the detection electrodes have portions where they are mutually opposed with respect to the width direction of the vibrating member.

23. A vibrator according to claim 22, wherein the length of the portions where the drive electrode and each of the detection electrodes are mutually opposed with respect to the width direction of the vibrating member is less than that of the portions where the drive electrode and each of the detection electrodes are mutually opposed with respect to the length direction of the vibrating body.

24. A vibration gyro comprising a vibrator according to claim 18.

25. An electronic device comprising a vibration gyro according to claim 24.