EP 0254813 B1 19910731 - DETECTION METHOD FOR A PASSIVE INFRARED MOTION DETECTOR AND ARRANGEMENT FOR CARRYING OUT THE METHOD
Title (en)
DETECTION METHOD FOR A PASSIVE INFRARED MOTION DETECTOR AND ARRANGEMENT FOR CARRYING OUT THE METHOD
Publication
Application
Priority
DE 3624195 A 19860717
Abstract (en)
[origin: EP0254813A2] A method of analysis for recognising objects remaining within the detection area of a passive infrared movement alarm and an arrangement for implementing the method are described. In accordance with the invention, the non-uniformity of the measurement background, which depends on physical factors such as absorption, reflection, specific thermal conductivity or varying influence of foreign radiation, is used for the analysis. With a variation in the background radiation field occurring below a lowest specified signal frequency, a background field correction is carried out which adjusts the particular reference value to match the change in the measurement background field. To make the correction, the difference between the current output signal of the radiation detector and an appropriately delayed output signal is taken via a signal amplitude-dependent time- varying reference-level correction circuit to a comparator which controls a timing element and a memory device. <IMAGE>
IPC 1-7
IPC 8 full level
G08B 13/18 (2006.01); G08B 13/191 (2006.01)
CPC (source: EP)
G08B 13/191 (2013.01)
Designated contracting state (EPC)
AT BE CH DE ES FR GB IT LI LU NL
DOCDB simple family (publication)
EP 0254813 A2 19880203; EP 0254813 A3 19880928; EP 0254813 B1 19910731; AT E65854 T1 19910815; DE 3624195 A1 19880121; DE 3624195 C2 19890323; DE 3771798 D1 19910905
DOCDB simple family (application)
EP 87105734 A 19870416; AT 87105734 T 19870416; DE 3624195 A 19860717; DE 3771798 T 19870416