Piezoelectric vibration gyro-sensor
View Patent ↗The present invention provides a piezoelectric vibration gyro-sensor utilizing Coriolis force that includes a tuning fork type vibrator in which two rectangular-columnar arms and a base to support the lower end of the arms are integrated; drive electrodes formed on two rectangular-columnar arms; and IDT electrodes of a surface acoustic wave element formed on two arms. Two pairs of the drive electrodes are provided on each rectangular-columnar arm, in which each of the pairs of drive electrodes face each other, and each pair of the drive electrodes are arranged in parallel on the rectangular-columnar arm at a given distance. The IDT electrodes of the surface acoustic wave element are provided between the drive electrodes at the lower end of the rectangular-columnar arms.
1. A piezoelectric vibration gyro-sensor comprising:
a tuning fork type vibrator comprising:
two rectangular-columnar arms integrated with a base to support lower ends of said arms;
primary electrodes on each of said two arms; and
secondary electrodes of a surface acoustic wave element on each of said two arms, wherein:
two pairs of said primary electrodes are provided on each said arm, said primary electrodes of each said pair of said primary electrodes on each said arm face each other, and each said pair of said primary electrodes are arranged in parallel at a given distance on said arms;
each said secondary electrode of said surface acoustic wave element is provided between said primary electrodes at said lower ends of said arms.
2. The piezoelectric vibration gyro-sensor according to claim 1 , wherein:
said tuning fork type vibrator is made of a X-cut quartz crystal; and
a longitudinal direction of said arms is parallel with a Y-direction of an axis of said quartz crystal.
3. The piezoelectric vibration gyro-sensor according to claim 1 , wherein said primary electrodes are drive electrodes and said secondary electrodes are IDT electrodes.
4. The piezoelectric vibration gyro-sensor according to claim 1 , further comprising:
two oscillation circuits; and
a detector comprising a frequency mixer, a frequency detector, and a synchronous detector.
5. The piezoelectric vibration gyro-sensor according to claim 1 , further comprising:
two oscillation circuits; and
a detector comprising a first frequency detector, a second frequency detector, a differential amplifier, and a synchronous detector.
6. The piezoelectric vibration gyro-sensor according to claim 1 , wherein said primary electrodes and said secondary electrodes are formed on an X-cut surface.
7. The piezoelectric vibration gyro-sensor according to claim 1 , wherein said tuning fork type vibrator is characterized by a single major crystal axis.