Tuning fork vibrator, vibrating gyroscope using the same, electronic apparatus using the same, and manufacturing method of the same

• US 6,799,461 B2
• Filed: 06/04/2003
• Issued: 10/05/2004
• Est. Priority Date: 06/04/2002
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Fujimoto, Katsumi, Yamamoto, Hironari
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US10/454,587
• Publication Number:
  US 20040007065A1
• Time in Patent Office: 489 Days
• Field of Search: 735/041.6, 331/156, 310/329, 310/370
• 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
• CPC Class Codes: Y10T 29/42 Piezoelectric device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/49574 Musical instrument or tuning fork making
• CPC Class Codes: Y10T 29/49792 Dividing through modified portion
• CPC Class Codes: Y10T 29/49798 Dividing sequentially from leading end, e.g., by cutting or breaking
• CPC Class Codes: Y10T 74/1275 Electrical

Abstract

A tuning fork vibrator includes a long plate-shaped vibration unit having a first principal surface and a second principal surface, a base disposed at one end of the second principal surface of the vibration unit in the longitudinal direction, and a slit for dividing the vibration unit into two legs defining a tuning fork along the longitudinal direction symmetrically in the width direction of the vibration unit. The slit is formed so as to include a portion of the base in the vicinity to the vibration unit.

Claims

1. A tuning fork vibrator comprising:

a plate-shaped vibration unit having a first principal surface and a second principal surface;

a base provided at one end of the second principal surface of the vibration unit in a longitudinal direction thereof;

wherein

at least one slit for dividing the vibration unit into at least two legs along the longitudinal direction symmetrically in a width direction of the vibration unit is provided in the vibration unit; and

the at least one slit is arranged to include a portion of the base in proximity to the vibration unit.

2. A vibrator according to claim 1, wherein the at least one slit includes at least two slits and the vibration unit is divided into at least three legs by the at least two slits, the vibrator further includes a support pin fixed at one of the at least three legs located in the vicinity of the center of the second principal surface, said support pin supporting the vibration unit and the base in midair.

3. A vibrator according to claim 1, wherein the base has a substantially U-shaped configuration including three straight line-segments surrounding the vibration unit on said one end side in the longitudinal direction and two sides in the width direction.

4. A vibrator according to claim 1, wherein the base has a substantially rectangular frame-shape surrounding the vibration unit on two end sides in the longitudinal direction and two sides in the width direction.

5. A vibrator according to claim 1, wherein the base is integrated at least with the second principal surface of the vibration unit.

6. A vibrator according to claim 1, wherein the base is provided separately from the vibration unit, and the base is bonded to the vibration unit.

7. A vibrator according to claim 1, wherein the vibration unit includes bonded piezoelectric members which are polarized in opposite directions of thickness relative to each other between the first principal surface and the second principal surface of the vibration unit.

8. A vibrator according to claim 1, wherein the vibration unit includes a piezoelectric member which is polarized in a thickness direction and a non-piezoelectric material which are bonded together.

9. A vibrator according to claim 1, wherein the vibration unit includes a non-piezoelectric material, in which a piezoelectric element which is polarized in a thickness direction of the vibration unit is provided on the first principal surface of the non-piezoelectric material.

10. A vibrating gyroscope comprising:

a tuning fork vibrator including;

a plate-shaped vibration unit having a first principal surface and a second principal surface;

a base provided at one end of the second principal surface of the vibration unit in a longitudinal direction thereof;

wherein

at least one slit for dividing the vibration unit into at least two legs along the longitudinal direction symmetrically in a width direction of the vibration unit is provided in the vibration unit; and

the at least one slit is arranged to include a portion of the base in proximity to the vibration unit.

11. The vibrating gyroscope according to claim 10, further comprising an oscillating circuit for driving the vibrator.

12. The vibrating gyroscope according to claim 10, further comprising a signal-processing circuit to which signals from the vibrator are applied and from which signals corresponding to a direction and a degree of angular velocity are output.