| 摘要 |
<p>PROBLEM TO BE SOLVED: To enhance the detection accuracy of an intruding body or a human body which intrudes into a detection range. SOLUTION: When an infrared detection part 11 detects infrared rays radiated by a human body moving inside a detection range, it outputs a detection signal (a). An ultrasonic transmission part 13 transmits pulse-shaped ultrasonic waves to the detection range, and an ultrasonic reception part 14 receives reflected waves from the detection range so as to output a reflection signal. A comparison part 16 outputs a detection signal (b) on the basis of a reflected waveform from the ultrasonic reception part 14 and on the basis of a reference waveform which is stored in a storage part 15. A judgment part 12 outputs a human-body detection signal (c) on the basis of the detection signal (a) from the infrared detection part 11 and on the basis of the detection signal (b) from the comparison part 16. When the judgment part 12 stops the output of the human-body detection signal (c) and when the waveform of the reflection signal is kept constant for a prescribed time, the comparison part 16 stores the waveform into the storage part 15 as the reference waveform.</p> |
