| 摘要 |
PROBLEM TO BE SOLVED: To appropriately perform self-diagnosis even if a detecting spring has high rigidity in a capacitive acceleration sensor having a self-diagnostic function performing self-diagnosis by applying a self-diagnostic signal so as to displace the detecting spring and causing a movable electrode to generate pseudo acceleration. SOLUTION: In a capacitive physical quantity detector, fixed electrodes 31, 41 are supported to a first silicon substrate 11 via springs 32, 42 for the fixed electrodes wherein the springs can be elastically displaced in a y-axial direction perpendicular to an x-axis while the springs can not be displaced elastically in an x-axial direction in which a movable electrode 23 is displaced. The physical quantity detector includes a fixed-electrode displacement means 60 for displacing the fixed electrodes 31, 41 in such a direction that facing areas between the movable electrode 23 and the fixed electrodes 31, 41 in the y-axial direction are increased by elastically displacing the springs 32, 42 for the fixed electrodes by means of an electrostatic attraction force. Self-diagnosis is performed by the fixed-electrode displacement means 60 while the facing areas between the movable electrode 23 and the fixed electrodes 31, 41 are increased as compared to a case when acceleration is detected. COPYRIGHT: (C)2011,JPO&INPIT |
