| 摘要 |
PURPOSE:To provide an angular speed sensor which is not susceptible to an offset signal. CONSTITUTION:An exciting circuit 30 applies an AC voltage to a tuning fork type sensor element 10 thus causing steady oscillation in the x-axis direction. A signal processing circuit 40 averages a plurality of electric signals corresponding to the period of AC voltage taken out from electric signals reflecting the oscillation state in y-axis direction of the sensor element 10 caused by the piezoelectric effect of piezoelectric elements 24, 25 for detection when the rotational angular speed does not function and delivers the averaged electric signal, as an offset signal, to an offset waveform memory circuit 50. The offset signal is delivered at a predetermined timing from the circuit 50 and the voltage thereof is inverted by an output voltage inverting circuit 52 and then a predetermined voltage level is set at a gain regulating circuit 54 before it is applied to piezoelectric elements 26, 27 for regulating the oscillation. Consequently, oscillation of the sensor element 10 is offset in the y-axis direction. When the sensor element 10 is subjected to a rotational angular speed, only an oscillation caused by the rotational angular speed takes places in the y-axis direction. |
