| 摘要 |
PROBLEM TO BE SOLVED: To obtain a piezoelectric vibrating gyro which is small and whose accuracy is high, by making a first electrode and a second electrode on one side and a third electrode and a four electrode on the other side opposed to each other on a main face, applying a driving voltage across both of them, and detecting electromotive force across the third electrode and the fourth electrode. SOLUTION: A first electrode 11 and a second electrode 12 are installed on the main face in the central part of a piezoelectric plate 10, and a third electrode 13 and a fourth electrode 14 are installed opposedly to in parallel with the electrodes 11 and 12 while being separated from them by a prescribed distance. A driving voltage is applied across the electrodes 11, 12 and the electrode 13, 14, a vibration in the X-direction is excited, the piezoelectric plate 10 is turned around the Z-axis, a vibration due to the Coriolis force is generated in the Y- direction, and an electromotive force is generated across the electrode 11 and the electrode 14. When the force is detected, a rotational angular velocity is detected. In addition, when the symmetric property of the electrodes 11, 12 and the electrodes 13, 14 is lost in their manufacture, a variable resistor 28 is installed and adjusted so as to correct the symmetry of output currents to a current detection circuit 21 and a current detection circuit 22. By this method, it is possible to obtain a piezoelectric vibrating gyro whose accuracy is high. |
