| 摘要 |
PURPOSE:To enable temperature dependency to be reduced and sensitivity of other axis to be reduced by allowing upper and lower electrodes of a center lever type semiconductor acceleration sensor to be grasped with electrodes and by acceleration to be detected by two electrostatic capacities which are formed with a mass part. CONSTITUTION:A sensor main body is maintained so that a gap G is formed between a lower stopper 43 for limiting displacement of a mass part 44 toward a lower side and an upper stopper 42 to enable displacement to an upper side of the mass part 44 and can be displaced within this gap. Then, a lower electrode 47 and an upper electrode 46 are placed at the stoppers 43 and 42, thus enabling capacity among the mass part 47, the electrode 47, and the electrode 46 to be detected separately. Capacities 51 and 52 among these mass pat 44 and the electrodes 47 and 46 are detected by capacity detectors 53 and 54 and both outputs are fed to a subtractor 55, thus enabling difference of both signals to be taken out. Then, this acceleration sensor is installed so that acceleration is applied in vertical direction of the sensor chip, thus achieving detection as a displacement of the center lever 49 due to acceleration. |
