| 摘要 |
An angular rate detector is disclosed having a first and a second detecting electrode 6a, 7a, which detect a second oscillation produced by Coriolis force, and disposed at locations which are symmetrical with respect to a direction of excitation D2 of a piezoelectric oscillator 2 and which corresponds to nodes of a first oscillation produced by the excitation. When the piezoelectric oscillator 2 rotates in a certain direction, a first signal appearing at the first detecting electrode 6a will be lagging in phase while a second signal appearing at the second detecting electrode 7a will be leading in phase. An electrical circuit produces an angular rate signal which represents a phase difference between the first and the second signal. In order to achieve a level of the first and the second signal which can be sensed by the electrical circuit it the angular rate is equal to zero, in a first embodiment, the first and the second detecting electrode 6a, 7a are disposed so as to be offset from nodes of the first oscillation of the oscillator 2 by an amount (-) toward the direction of the first oscillation D2. In a second embodiment, impedances of electrical circuits of the vibration system D2 and the detection system D3, D4 are chosen so that the resonant frequencies of the first and the second oscillation are different relative to each other. In a third embodiment, a weight is added to or a notch is formed in the oscillator to achieve a relative offset between the resonant frequencies of the first and the second oscillation.
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