| 摘要 |
PROBLEM TO BE SOLVED: To provide an invasion detector which can stably and highly precisely detect the invasion of an article to a monitoring area. SOLUTION: The invasion detector is provided with optical fibers 4 which are arranged in accordance with a monitoring area regulated by fences 10 and polarize/fluctuate propagating light when external force is added in accordance with external force, a light source 2 emitting light into the optical fibers 4, an operation processing part 22 generating an operation result signal S22 having a frequency corresponding to the polarization/fluctuation of light propagating through the optical fibers 4, a band pass filter 23 generating an operation result signal S23 by removing a frequency component by polarization/fluctuation, which is generated in light propagating through a light transmission line when the invasion of the object does not exist, from the frequency component included in the signal S22 and an invasion judgment part 25 monitoring the polarization/ fluctuation of light based on the operation result signal S23 and judging the presence or absence of an invader to the monitoring area based on the result of monitoring.
|
