| 摘要 |
PROBLEM TO BE SOLVED: To enable to detect in a short time approach of an detecting object when the electrostatic capacity is large. SOLUTION: When the electrostatic capacity C of a sensor part 10 is smaller than a prescribed value, a standard operation of starting charge to the sensor part from a discharge state is carried out, and when the electrostatic capacity of the sensor part 10 is larger than the prescribed value, charges precharged by a precharge circuit 21 is supplied to the sensor part 10, and after the charge starting voltage at the sensor part 10 is raised at one time, a correction operation of starting charge to the sensor part 10 is carried out. As described above, according to the electrostatic capacity of the sensor part 10, CPU 26 drives a plurality of switches SW and switches over the standard operation and correction operation. COPYRIGHT: (C)2007,JPO&INPIT
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