| 摘要 |
<P>PROBLEM TO BE SOLVED: To significantly reduce occurrence of false alarms and alarm failures by minimizing effects of external light and noise and setting many identifiable signals. <P>SOLUTION: Five infrared sensors are set in different height positions in every interval of bodies 10A to 10H, and all the infrared sensors emit and receive thirty-five infrared rays pulse-coded by an asynchronous method. The pulse-coded infrared rays are emitted by delayed synchronous signals in time series with given delay times in a period of, for example, 20 ms, and the pulse codes of the infrared rays are identified for intrusion monitoring. The scheme prevents radio interference between the plurality of infrared sensors and outputs the infrared rays for a short time to reduce effects of external light and the like. Increased illuminance on the infrared sensors triggers a report of a high level environment. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
