EP 0186226 B1 19900228 - INTRUSION DETECTION SYSTEM WITH AN ANTI-MASKING DEVICE
Title (en)
INTRUSION DETECTION SYSTEM WITH AN ANTI-MASKING DEVICE
Publication
Application
Priority
FR 8418288 A 19841130
Abstract (en)
[origin: US4752768A] An apparatus for detecting intruders comprising a housing provided with at least one window, a passive infrared detector (for detecting the radiation emitted by an intruder around a wavelength lambda 1), and an anti-obscuring device (detecting by infrared radiation having a wavelength lambda 2 the presence of an obscuring of the appparatus for detecting intruders). The apparatus further includes an electronic circuit intended to operate an alarm when the presence of an intruder or an obscuring element has been detected. The apparatus for detecting intruders has a detector for detecting an obscuring element arranged at small and at large distances. It further includes a self-verification circuit. An obscuring element is detected, inter alia, by a mirror arranged at the end of the zone to be supervised, which returns radiation lambda 2 emitted by an emitter to a detector, both being situated very close to the detector of radiation having a wavelength lambda 1.
IPC 1-7
IPC 8 full level
G01J 1/02 (2006.01); G01V 8/10 (2006.01); G08B 13/00 (2006.01); G08B 13/18 (2006.01); G08B 13/181 (2006.01); G08B 13/19 (2006.01); G08B 29/04 (2006.01)
CPC (source: EP US)
G08B 13/19 (2013.01 - EP US); G08B 29/046 (2013.01 - EP US); Y10S 250/01 (2013.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT
DOCDB simple family (publication)
EP 0186226 A1 19860702; EP 0186226 B1 19900228; DE 3576231 D1 19900405; FR 2574200 A1 19860606; FR 2574200 B1 19870123; JP S61131198 A 19860618; US 4752768 A 19880621
DOCDB simple family (application)
EP 85201873 A 19851114; DE 3576231 T 19851114; FR 8418288 A 19841130; JP 26756685 A 19851129; US 80088985 A 19851122