Visonic ltd from Israel
http://www.patentstorm.us/patents/7250605/description.html visonic ltd Various solutions have been proposed for outdoor applications by manufacturers such as
* Optex Co. Ltd. of Japan, * Crow Electronic Engineering Ltd. of Israel, * Paradox Security Systems Ltd. of Canada. * http://www.visonic.com/
Generally, the proposed solutionsincorporate two sensors, having generally overlapping fields-of-view, into the same detector housing to activate a common alarm output upon generally simultaneous detection of motion by both sensors. Prevention of false alarms is based on thestatistical assumption that the probability that each of the two sensors will generate a false alarm at approximately the same instant is very low. On the other hand, inasmuch as both detectors have more or less the same field-of-view, detectionprocessing is based on detecting a "desired signal" in both sensors at approximately the same time. Although such detectors perform better outdoors than a detector employing a single sensor, they still do not provide sufficiently reliable detection,because much of the interference existing outdoors, as explained hereinabove, generates "undesired signals" simultaneously in both sensors, due inter-alia, to the fact that both sensors view the same field-of-vie
fence scaling detection
http://www.patentstorm.us/patents/7068166/description.html references Japanese patent that uses optic cables to detect reflection from object, if cable is bent an alarm is triggered. Uses OTDR (optical time domain reflectometry)
Infrared occupancy sensor
http://www.patentstorm.us/patents/7541924/description.html An occupancy sensor includes an infrared sensor, a variable bandpass filter operably coupled to the infrared sensor and a controller operably coupled to the infrared sensor and the variable bandpass filter. The bandpass filter includes digital potentiometers adapted.
opto electronic security fence
Person and object recognition
* Datatec industries
Uses beams reflected off object or person to classify object.
Body falling in pool detection
ebay seller of PIR