| 摘要 |
PROBLEM TO BE SOLVED: To increase a detection distance in front of a front member if a dielectric member is located in front of an electrode, and an object to be detected approaching a surface of the front member is detected on a backside of the front member. SOLUTION: In an electrostatic capacitance type proximity sensor, an electrostatic capacitance is changed if the object to be detected as a grounded body such as a human body approaches the electrode for composing a capacitor, and an electrical circuit detects an approach of the object to be detected. In the configuration, the dielectric member is located in front of the electrode, and the object to be detected approaching the surface of the front member is detected on the backside of the front member. The electrical circuit configures a series resonance circuit formed by connecting the capacitor including the electrodes, a coil and a generating source, converts a change in the electrostatic capacitance into a change in a current or a voltage, and detects the approach of the object to be detected, based on the change in the current or the voltage. A frequency f of an AC generated by the generating source is set to a frequency fs for increasing the changeΔE of the voltage E or the current while there is the front member based on a series resonance characteristic curve when there is the front member. COPYRIGHT: (C)2010,JPO&INPIT
|
