| 摘要 |
PROBLEM TO BE SOLVED: To detect magnetism of a magnet for outputting an alarm signal in an alarm signal output device even if reducing dynamic sensitivity of an LC resonator by use of the magnet or the like, or even if disenabling operation of the LC resonator. SOLUTION: This alarm signal output device outputting the alarm signal when a signal of a specific frequency component is detected from an ultrasonic signal by the LC resonator is provided with a magnetic sensor 5 for detecting the magnetism disturbing operation of the LC resonator 2, and outputs the alarm signal when the magnetic sensor 5 detects the magnetism. COPYRIGHT: (C)2005,JPO&NCIPI
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