| 摘要 |
PURPOSE: To provide a detection apparatus whose sensitivity is high and stable without changing the constitution of the apparatus largely by a method wherein the distance between a displacement substrate and a fixed substrate is controlled so as to be kept constant by the Coulomb force of an electrode. CONSTITUTION: The movement amount in the Z-axis of a flexible substrate (a displacement substrate) is found by the sum of change amounts of capacitance elements C1 to C4. Consequently, when an acceleration is applied to a point of application and the flexible substrate becomes distant from the fixed substrate, a capacitance becomes small, and the output voltage of a terminal Tz becomes small. The voltage is compared with a reference voltage 93 corresponding to the reference distance between the flexible substrate and the fixed substrate, and a difference voltage is applied to a capacitance element which is composed of electrodes 15, 25. The distance between the flexible substrate and the fixed substrate is controlled so as to be kept constant by the Coulomb force by the applied voltage. In addition, a voltage which is proportional to an acceleration in the Z-axis is outputted by the voltage applied across the electrodes 15, 25. The acceleration in the Z-axis becomes a voltage which is proportional to the Coulomb force which makes the displacement in the Z-axis of the flexible substrate by the acceleration stationary, and a correction arithmetic operation by the position of the flexible substrate is not required. |
