Abstract: A drive circuit supplies a FB (feedback) signal having a predetermined frequency to drive electrodes to vibrate a vibrator. An angular velocity detecting circuit detects a vibratory movement caused in a direction normal to an oscillating direction of the vibrator based on a sensing signal of angular velocity sensing electrodes, thereby generating an angular velocity signal. A signal input circuit supplies a diagnostic signal having a frequency different from that of the FB signal, which is entered into the vibrator via diagnosing electrodes. A diagnosis circuit generates a breakdown signal based on a signal responsive to the diagnostic signal which is obtained from at least one of the drive electrodes and the angular velocity sensing electrodes.

Abstract: An angular rate sensor is provided which measures the angular rate of motion applied to a moving object and which features the structure minimizing electrical noise of an output. The angular rate sensor includes generally a first tuning fork, a second tuning fork, and a torsion beam. The first tuning fork includes two tines and serves as a drive oscillator and a measuring oscillator. The second tuning fork includes two tines which extend in the same direction as the first and second tines partially surrounding the first tuning fork and which connect at ends thereof with ends of the tines of the first tuning fork through a stem extending substantially perpendicular to the tines of the first and second tuning forks. The torsion beam extends substantially along the center line of the sensor and supports the stem on a base.

Abstract: A method of improving an output characteristic of an angular rate sensor including, for example, a fork oscillator and an improved structure of an angular rate sensor are provided. The improvement of the output characteristic is achieved by adjusting a physical structure of the oscillator to minimize unwanted vibrations of the oscillator or noises of a sensor output. The adjustment of the physical structure is achieved by trimming away an edge portion of the oscillator or a supporter for supporting the oscillator on a base.

Abstract: Drive electrodes and sensing electrodes are formed on a front face of a piezoelectric body of a vibrator. A first reference electrode is formed on a rear face. Second reference electrodes are formed on side faces of arm bars of the vibrator at a position corresponding to the sensing electrodes. The second reference electrodes are connected to the first reference electrode formed on said rear face.

Abstract: An angular velocity detector includes vibrator made of piezoelectric material and having a pair of arms. A pair of driving electrodes are attached to the arms in order to generate vibrations in the arms. A pair of detecting electrodes, which are attached to the arms, detect the vibrations of the arms. Therefore, the pair of driving electrodes can cause the arms to vibrate uniformly and stably, so that a S/N ratio of the angular velocity sensor can be improved.