EP 0334531 A1 19890927 - Concealable proximity detector.
Title (en)
Concealable proximity detector.
Title (de)
Versteckbarer Näherungsdetektor.
Title (fr)
Détecteur de proximité dissimulable.
Publication
Application
Priority
GB 8806734 A 19880322
Abstract (en)
A concealable proximity detector for detecting the approach of matter towards a target (1) (e.g. a room or doorway) and especially useful in intruder detection systems. The detector employs a capacitor which uses as its first electrode (51) a coat (2) of electrically conductive paint applied to the target which is concealed beneath or as part of the decoration of the target. The capacitor uses as its second electrode a (preferably earthed) surface (4) which is part of the surroundings of the first electrode (e.g. a floor or pavement) and which is therefore also inconspicuous. The capacitor and switching means serve as part of a proximity switch operable in response to the change in dielectric between the capacitor electrodes which occurs when an intruder in contact with the second electrode surface approaches the painted surface.
IPC 1-7
IPC 8 full level
G08B 13/26 (2006.01)
CPC (source: EP)
G08B 13/26 (2013.01)
Citation (search report)
NO RELEVANT DOCUMENTS HAVE BEEN DISCLOSED
Designated contracting state (EPC)
AT BE CH DE ES FR GB GR IT LI LU NL SE
DOCDB simple family (publication)
DOCDB simple family (application)
EP 89302494 A 19890314; GB 8806734 A 19880322