| 摘要 |
PROBLEM TO BE SOLVED: To drive an electromagnetic coil simultaneously when detecting approach and leaving of an object to be detected and constitute a driving device for driving the electromagnetic coil by a simple configuration inexpensively by dispensing with a complicated signal processing circuit. SOLUTION: Output of a Doppler sensor 10 is used as a driving source to drive the electromagnetic coil 28. The Doppler sensor 10 outputs positive and negative voltages when the moving object to be detected approaches and leaves to drive the electromagnetic coil 28 in one direction by positive voltage output and in the other direction by negative voltage output. The Doppler sensor 10 is arranged by deviating a position of a second reception part 18 for a first reception part 16 by n(λ/2) +λ/4 (n:integer) when wavelength of transmission wave isλ. COPYRIGHT: (C)2004,JPO |
