Angular rate sensor

• US 6,523,410 B2
• Filed: 10/09/2001
• Issued: 02/25/2003
• Est. Priority Date: 12/14/1999
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Hatanaka, Masakazu, Matsubara, Katsunori, Yukawa, Junichi, Ouchi, Satoshi
• Primary Examiner(s): MOLLER, RICHARD ALAN
• Application Number:
  US09/890,458
• Publication Number:
  US 20020134156A1
• Time in Patent Office: 504 Days
• Field of Search: 735/041.6, 735/041.5, 735/041.2, 735/040.2
• US Class Current: 73/504.16
• CPC Class Codes: G01C 19/5607 using vibrating tuning forks double-ended tuning forks using planar vibrating masses suspended at opposite ends G01C19/5719

Abstract

An object of the present invention is to improve the efficiency of a driving operation of an angular rate sensor employing a tuning fork oscillator made of single crystalline piezoelectric material such as quartz. In order to achieve the object of the present invention, a tuning fork oscillator assembled directly has driver electrodes and detector electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of a arm, respectively. The oscillator also has a driver electrode, a monitor electrode, and detector electrodes provided on a first main surface, a second main surface, an inner surface, and an outer surface of the other arm thereof, respectively. A driving voltage is supplied from a driving power source so that the two driver electrodes may be equal in the polarity while the polarity of the driver electrode is opposite to that of the driver electrodes.

Claims

1. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first, second, third, and fourth electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of one of the arms of said tuning fork oscillator, respectively;

a fifth electrode provided on one of first and second main surfaces of other arm of the arms of said tuning fork oscillator; and

sixth and seventh electrodes provided on inner and outer surfaces of the other arm of said tuning fork oscillator, respectively;

wherein, when said fifth electrode is provided on the first main surface, a driving voltage is applied to said second and fifth electrodes at a polarity identical to each other and applied to said first electrode at a polarity opposite to said second and fifth electrodes; and

wherein, when said fifth electrode is provided on the second main surface, a driving voltage is applied to said second and fifth electrodes at polarities opposite to each other and applied to said first electrode at a polarity identical to said fifth electrode.

2. The angular rate sensor according to claim 1, wherein said third and seventh electrodes are connected to a common port, said fourth and sixth electrodes are connected to another common port, and a detection signal is detected from a differential signal between the common ports.

31. The angular rate sensor according to claim 1, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

32. The angular rate sensor according to claim 1, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

3. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first, second, third, and fourth electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of one of the arms of said tuning fork oscillator, respectively;

fifth and sixth electrodes provided on first and second main surfaces of other arm of the arms of said tuning fork oscillator, respectively, said fifth and sixth electrodes being provided on portions close to one of outer and inner surfaces of the other arm, respectively; and

a seventh electrode provided on a surface of the other arm of said tuning fork oscillator;

wherein, when said fifth and sixth electrodes are provided on the portions close to the outer surface of the other arm, respectively, said seventh electrode is provided on the outer surface;

wherein, when said fifth and sixth electrodes are provided on the portions close to the inner surface of the other arm, respectively, said seventh electrode is provided on the inner surface; and

wherein a driving voltage is applied to said first and sixth electrodes at a polarity identical to each other and applied to said second and fifth electrodes at a polarity opposite to said first and sixth electrodes.

4. The angular rate sensor according to claim 3, further comprising an eighth electrode provided on a surface opposite to the surface of the other arm of said tuning fork oscillator on which said seventh electrode is provided;

wherein, when said seventh electrode is provided on the outer surface, said fourth and eight electrodes are connected to a common port, said third and seventh electrodes are connected to another common port, and a detection signal is detected from a differential signal between the common ports; and

wherein, when said seventh electrode is provided on the inner surface, said third and eight electrodes are connected to a common port, said fourth and seventh electrodes are connected to another common port, and a detection signal is detected from a differential signal between the common ports.

43. The angular rate sensor according to claim 3, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

54. The angular rate sensor according to claim 3, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

55. The angular rate sensor according to claim 4, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

5. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first, second, third, and fourth electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of one of the arms of said tuning fork oscillator, respectively; and

fifth, sixth, seventh, and eighth electrodes provided on a first main surface, a second main surface, an outer surface, and an inner surface of other arm of the arms of said tuning fork oscillator, respectively;

wherein, when said fifth electrode is provided on a portion close to the outer surface of the other arm, said sixth electrode is provided on a portion close to the inner surface of the other arm;

wherein, when said fifth electrode is provided on a portion close to the inner surface of the other arm, said sixth electrode is provided on a portion close to the outer surface of the other arm; and

wherein a driving voltage is applied to said first and sixth electrodes at a polarity identical to each other and applied to said second and fifth electrodes at a polarity opposite to said first and sixth electrodes.

6. The angular rate sensor according to claim 5, wherein a detection signal is detected from a differential signal between said third and fourth electrodes.

44. The angular rate sensor according to claim 5, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

56. The angular rate sensor according to claim 5, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

57. The angular rate sensor according to claim 6, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

7. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively;

third and fourth electrodes provided on one of outer and inner surfaces of the one of the arms, said third and fourth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively; and

a fifth electrode provided on a surface opposite to the surface on which said third and fourth electrodes are provided;

wherein a driving voltage is applied to said first and fourth electrodes at a polarity identical to each other and applied to said second and third electrodes at a polarity opposite to said first and fourth electrodes.

8. The angular rate sensor according to claim 7, further comprising sixth and seventh electrodes provided on inner and outer surfaces of the other arm of said tuning fork oscillator, respectively;

wherein, when said fifth electrode is provided on the inner surface of the one of the arms, a detection signal is detected from a differential signal between said sixth and seventh electrodes, or said fifth and sixth electrodes are connected to a common port, and a detection signal is detected from a differential signal between the common port and said seventh electrode; and

wherein, when said fifth electrode is provided on the outer surface of the one of the arms, a detection signal is detected from a differential signal between said sixth and seventh electrodes, or said fifth and seventh electrodes are connected to a common port, and a detection signal is detected from a differential signal between the common port and said sixth electrode.

9. The angular rate sensor according to claim 7, further comprising:

a sixth electrode provided on one of first and second main surfaces of the other arm of said tuning fork oscillator; and

seventh and eighth electrodes provided on inner and outer surfaces of the other arm, respectively;

wherein, when said sixth electrode is provided on the first main surface, a driving voltage is applied to said first and sixth electrodes at polarities opposite to each other; and

wherein, when said sixth electrode is provided on the second main surface, a driving voltage is applied to said first and sixth electrodes at a polarity identical to each other.

10. The angular rate sensor according to claim 9, wherein:

when said fifth electrode is provided on the inner surface of the one of the arms, a detection signal is detected from a differential signal between said seventh and eighth electrodes, or said fifth and seventh electrodes are connected to a common port, and a detection signal is detected from a differential signal between the common port and said eighth electrode; and

when said fifth electrode is provided on the outer surface of the one of the arms, a detection signal is detected from a differential signal between said seventh and eighth electrodes, or said fifth and eight electrodes are connected to a common port, and a detection signal is detected from a differential signal between the common port and said seventh electrode.

16. The angular rate sensor, according to claim 7, further comprising electrodes provided on inner surfaces of the arms of said tuning fork oscillator, respectively, wherein said electrodes being connected to a common port, and a detection signal is detected from the common port.

24. The angular rate sensor according to claim 16, further comprising:

two grounding electrodes provided on remaining portions of the first and second main surfaces of the one of the arms of said tuning fork oscillator, respectively; and

two monitor electrodes provided on remaining portions of the first and second main surfaces of the other arm.

33. The angular rate sensor according to claim 16, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

45. The angular rate sensor according to claim 7, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

58. The angular rate sensor according to claim 7, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

59. The angular rate sensor according to claim 8, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

60. The angular rate sensor according to claim 9, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

11. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively;

third and fourth electrodes provided on an outer surface of the one of the arms, said third and fourth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively; and

fifth and sixth electrodes provided on an inner surface of the one of the arms, said fifth and sixth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively;

wherein a driving voltage is applied to said first, fourth, and sixth electrodes at a polarity identical to one another and applied to said second, third, and fifth electrodes at a polarity opposite to said first, fourth, and sixth electrodes.

12. The angular rate sensor according to claim 11, further comprising seventh and eighth electrodes provided on inner and outer surfaces of the other arm of said tuning fork oscillator, respectively, wherein a detection signal is detected from a differential signal between said seventh and eighth electrodes.

13. The angular rate sensor according to claim 11, further comprising:

a seventh electrode provided on one of first and second main surfaces of other arm of the arms of said tuning fork oscillator; and

eighth and ninth electrodes provided on inner and outer surfaces of the other arm, respectively;

wherein, when said seventh electrode is provided on the first main surface, a driving voltage is applied to said first and seventh electrodes at polarities opposite to each other; and

wherein, when said seventh electrode is provided on the second main surface, a driving voltage is applied to said first and seventh electrodes at a polarity identical to each other.

14. The angular rate sensor according to claim 13, wherein a detection signal is detected from a differential signal between said eighth and ninth electrodes.

46. The angular rate sensor according to claim 11, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

61. The angular rate sensor according to claim 11, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

62. The angular rate sensor according to claim 12, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

63. The angular rate sensor according to claim 13, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

15. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively, said first and second electrodes being provided on portions close to an outer surface of the one of the arms, respectively;

third and fourth electrodes provided on the outer surface of the one of the arms, said third and fourth electrodes being provided on a portion close to the first main surface of the one of the arms and a portion close to the second main surface of the one of the arms, respectively;

fifth and sixth electrodes provided on first and second main surfaces of other arm of the arms of said tuning fork oscillator, said fifth and sixth electrodes being provided on portions close to an outer surface of the other arm of said tuning fork oscillator, respectively; and

seventh and eighth electrodes provided on the outer surface of the other arm, said seventh and eighth electrodes being provided on a portion close to the first main surface of the other arm and a portion close to the second main surface of the of the arm, respectively;

wherein a driving voltage is applied to said first, fourth, sixth, and seventh electrodes at a polarity identical to one another and applied to said second, third, fifth, and eighth electrodes at a polarity opposite to said first, fourth, sixth, and seventh electrodes.

23. The angular rate sensor according to claim 15, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

47. The angular rate sensor according to claim 15, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

64. The angular rate sensor according to claim 15, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

17. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms;

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively, said first and second electrodes being provided on portions close to an inner surface of the one of the arms, respectively;

third and fourth electrodes provided on the inner surface of the one of the arms, said third and fourth electrodes being provided on a portion close to the first main surface of the one of the arms and a portion close to the second main surface of the one of the arms, respectively;

fifth and sixth electrodes provided on first and second main surfaces of other arm of the arms of said tuning fork oscillator, respectively, said fifth and sixth electrodes being provided on portions close to an inner surface of the other arm, respectively; and

seventh and eighth electrodes provided on the inner surface of the other arm, said seventh and eighth electrodes being provided on a portion close to the first main surface of the other arm and a portion close to the second main surface of the other arm, respectively;

wherein a driving voltage is applied to said first, fourth, sixth, and seventh electrodes at a polarity identical to one another and applied to said second, third, fifth, and eighth electrodes at a polarity opposite to said first, fourth, sixth, and seventh electrodes.

18. The angular rate sensor according to claim 17, further comprising electrodes provided on outer surfaces of the arms of said tuning fork oscillator, respectively, wherein said electrodes are connected to a common port, and a detection signal is detected from the common port.

34. The angular rate sensor according to claim 17, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

35. The angular rate sensor according to claim 18, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

40. The angular rate sensor according to claim 18, further comprising:

two grounding electrodes provided on remaining portions of the first and second main surfaces of the one of the arms of said tuning fork oscillator, respectively; and

two monitor electrodes provided on remaining portions of the first and second main surfaces of the other arm.

48. The angular rate sensor according to claim 17, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

65. The angular rate sensor according to claim 17, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

19. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively, said first and second electrodes being provided on portions close to an outer surface of the one of the arms, respectively;

third and fourth electrodes provided on the outer surface of the one of the arms, said third and fourth electrodes being provided on a portion close to the first main surface of the one of the arms and a portion close to the second main surface of the one of the arms, respectively;

fifth and sixth electrodes provided on first and second main surfaces of other arm of the arms of said tuning fork oscillator, respectively, said fifth and sixth electrodes being provided on portions close to an inner surface of the other arm, respectively; and

seventh and eighth electrodes provided on the inner surface of the other arm, said seventh and eighth electrodes being provided on a portion close to the first main surface of the other arm and a portion close to the second main surface of the other arm, respectively;

wherein a driving voltage is applied to said first, fourth, sixth, and seventh electrodes at a polarity identical to one another and applied to said second, third, fifth, and eighth electrodes at a polarity opposite to said first, fourth, sixth, and seventh electrodes.

20. The angular rate sensor according to claim 19, further comprising:

a ninth electrode provided on an inner surface of the one of the arms of said tuning fork oscillator; and

a tenth electrode provided on an outer surface of the other arm, wherein a detection signal is detected from a differential signal between said ninth and tenth electrodes.

36. The angular rate sensor according to claim 19, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

37. The angular rate sensor according to claim 20, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

41. The angular rate sensor according to claim 20, further comprising:

two grounding electrodes provided on remaining portions of the first and second main surfaces of the one of the arms of said tuning fork oscillator, respectively; and

two monitor electrodes provided on remaining portions of the first and second main surfaces of the other arm.

49. The angular rate sensor according to claim 19, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

66. The angular rate sensor according to claim 19, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

21. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively, said first and second electrodes being provided on portions close to an inner surface of the one of the arms, respectively;

third and fourth electrodes provided on the inner surface of the one of the arms, said third and fourth electrodes being provided on a portion close to the first main surface of the one of the arms and a portion close to the second main surface of the one of the arms, respectively;

fifth and sixth electrodes provided on first and second main surfaces of other arm of the arms of said tuning fork oscillator, respectively, said fifth and sixth electrodes being provided on portions close to an outer surface of the other arm, respectively; and

seventh and eighth electrodes provided on the outer surface of the other arm, said seventh and eighth electrodes being provided on a portion close to the first main surface of the other arm and a portion close to the second main surface of the other arm, respectively;

wherein a driving voltage is applied to said first, fourth, sixth, and seventh electrodes at a polarity identical to one another and applied to said second, third, fifth, and eighth electrodes at a polarity opposite to said first, fourth, sixth, and seventh electrodes.

22. The angular rate sensor according to claim 21, further comprising:

a ninth electrode provided on an outer surface of the one of the arms of said tuning fork oscillator; and

a tenth electrode provided on an inner surface of the other arm,

wherein a detection signal is detected from a differential signal between said ninth and tenth electrodes.

38. The angular rate sensor according to claim 21, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

39. The angular rate sensor according to claim 22, further comprising four monitor electrodes provided on remaining portions of the first and second main surfaces of the arms of said tuning fork oscillator, respectively.

42. The angular rate sensor according to claim 22, further comprising:

two grounding electrodes provided on remaining portions of the first and second main surfaces of the one of the arms of said tuning fork oscillator, respectively; and

two monitor electrodes provided on remaining portions of the first and second main surfaces of the other arm.

50. The angular rate sensor according to claim 21, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

67. The angular rate sensor according to claim 21, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

25. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively;

third and fourth electrodes provided on one of outer and inner surfaces of the one of the arms, said third and fourth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively;

a fifth electrode provided on one of the inner and outer surfaces of the one of the arms, said fifth electrode being provided on a surface opposite to the surface on which said third and fourth electrodes are provided;

sixth and seventh electrodes provided on first and second main surfaces of other arm of said arms of the tuning fork oscillator, respectively, said sixth and seventh electrodes being provided on portions close to an outer surface of the other arm, respectively; and

eighth and ninth electrodes provided on the outer surface of the other arm, said eighth and ninth electrodes being provided on a portion close to said sixth electrode and a portion close to said seventh electrode, respectively, wherein a driving voltage is applied to said first, fourth, seventh, and eighth electrodes at a polarity identical to one another and applied to said second, third, sixth, and ninth electrodes at a polarity opposite to said first, fourth, seventh, and eighth electrodes.

26. The angular rate sensor according to claim 25, further comprising:

a tenth electrode provided on an inner surface of the other arm of said tuning fork oscillator; and

two monitor electrodes provided on remaining portions of the first and second main surfaces of the other arm, respectively;

wherein, when said fifth electrode is provided on the inner surface of the one of the arms, said fifth and tenth electrodes are connected to a common port from which a detection signal is detected; and

wherein, when said fifth electrode is provided on the outer surface of the one of the arms, a detection signal is detected from a differential signal between said fifth and tenth electrodes.

51. The angular rate sensor according to claim 25, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

68. The angular rate sensor according to claim 25, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

27. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively;

third and fourth electrodes provided on one of outer and inner surfaces of the one of the arms, said third and fourth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively;

a fifth electrode provided on one of the inner and outer surfaces of the one of the arms, said fifth electrode being disposed on a surface opposite to the surface on which said third and fourth electrodes are provided;

sixth and seventh electrodes provided on first and second main surfaces of the other arm of the arms of said tuning fork oscillator, respectively, said sixth and seventh electrodes being provided on portions close to an inner surface of the other arm, respectively; and

eighth and ninth electrodes provided on the inner surface of the other arm, said eighth and ninth electrodes being provided on a portion close to said sixth electrode and a portion close to said seventh electrode, respectively;

wherein a driving voltage is applied to said first, fourth, seventh, and eighth electrodes at a polarity identical to one another and applied to said second, third, sixth, and ninth electrodes at a polarity opposite to said first, fourth, seventh, and eighth electrodes.

28. The angular rate sensor according to claim 27, further comprising:

a tenth electrode provided on an outer surface of said other arm of said tuning fork oscillator; and

two monitor electrodes provided on remaining portions of the first and second main surfaces of the other arm;

wherein, when said fifth electrode is provided on the inner surface of the one of the arms, a detection signal is detected from a differential signal between said fifth and tenth electrodes; and

wherein, when said fifth electrode is provided on the outer surface of the one of the arms, said fifth and tenth electrodes are connected to a common port from which a detection signal is detected.

52. The angular rate sensor according to claim 27, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

69. The angular rate sensor according to claim 27, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.

29. An angular rate sensor comprising:

a tuning fork oscillator having at least two arms and a base, including;

a first oscillator member of a single crystalline piezoelectric material having at least two arms and a base joining the two arms; and

a second oscillator member of the single crystalline piezoelectric material having a shape substantially identical to a shape of said first oscillator member, said first and second oscillator members being bonded directly to each other in a direction of a thickness and in a direction of a crystallographic axis so that opposite polarities of a piezoelectric effect may be developed along a widthwise direction of said first and second oscillator members;

first and second electrodes provided on first and second main surfaces of one of the arms of said tuning fork oscillator, respectively;

third and fourth electrodes provided on an outer surface of the one of the arms, said third and fourth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively;

fifth and sixth electrodes provided on an inner surface of the one of the arms, said fifth and sixth electrodes being provided on a portion close to said first electrode and a portion close to said second electrode, respectively;

a seventh electrode provided on one of first and second main surfaces of other arm of the arms of said tuning fork oscillator;

eighth and ninth electrodes provided on an outer surface of the other arm, said eighth and ninth electrodes being provided on a portion close to the first main surface of the other arm and a portion close to the second main surface of the other arm, respectively; and

tenth and eleventh electrodes provided on an inner surface of the other arm, said tenth and eleventh electrodes being provided on a portion close to the first main surface of the other arm and a portion close to the second main surface of the other arm, respectively;

wherein, when said seventh electrode is provided on the first main surface, a driving voltage is applied to said first, eighth, and tenth electrodes at a polarity identical to one another and applied to said second, third, fifth, and seventh electrodes at a polarity opposite to said first, eighth, and tenth electrodes; and

wherein, when said seventh electrode is provided on the second main surface, a driving voltage is applied to said first and seventh electrodes at a polarity identical to each other and applied to said second, third, fifth, ninth, and eleventh electrodes at a polarity opposite to said first and seventh electrodes.

30. The angular rate sensor according to claim 29, wherein:

when said seventh electrode is provided on the first main surface, said fourth and ninth electrodes are connected to a common port, said sixth and eleventh electrodes are connected to another common port, and a detection signal is detected from a differential signal between the common ports; and

when said seventh electrode is provided on the second main surface, said fourth and eighth electrodes are connected to a common port, said sixth and tenth electrodes are connected to another common port, and a detection signal is detected from a differential signal between the common ports.

53. The angular rate sensor according to claim 29, wherein the electrodes provided on the first and second main surfaces of the arms are extended onto a surface of the base.

70. The angular rate sensor according to claim 29, wherein the electrodes provided on the outer surfaces of the arms are extended onto a surface of the base.