| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a foreign substance detection sensor for improving the detection precision of an electrostatic capacity detected with a sensor electrode. Ž<P>SOLUTION: The foreign substance detection sensor 41 includes a pressure detection part 44 for outputting a voltage detection signal when the sensor body 42 is deformed by a prescribed amount. An oscillating circuit 81 oscillates at an oscillation frequency determined corresponding to an electrostatic capacity C1 between an external electrode 52 and a foreign substance X1 approaching the external electrode 52 and outputs an oscillating signal of the oscillation frequency. The electrostatic capacity detection part 43 measures the time necessary for an oscillating signal for 20,000 cycles to be output within the measurement time shorter than the reaction time necessary for a contact detection signal to be output when a door panel is operated at a maximum speed after the foreign substance X1 abuts on the sensor body 42 and outputs a measurement result each time the measurement time elapses. A determination part 45 determines the presence/absence of the foreign substance X1 between the door panel and an ingress/egress part based on the measurement result and determines on the presence/absence of the foreign substance X1 based on a contact detection signal. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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