Patent ID: 7705310
Filing Date: 2010-04-27
Classification: G01J,G08B,Y10S

Abstract:
1. A passive infra-red detector comprising: at least two sub-detectors, each operative to receive infra-red radiation from a corresponding one of at least two sub fields-of-view; and signal processing circuitry, receiving output signals from said at least two sub-detectors and noting time relationships of said output signals from said at least two sub-detectors and providing a motion detection output in response to receipt of said output signals from said at least two sub-detectors, representing traversal of said at least two sub fields-of-view, having a time relationship which meets at least one predetermined criterion, at least one of said at least one predetermined criterion being traversal of said at least two sub fields-of-view in a first direction at least a predetermined time following traversal of said at least two sub fields-of-view in a second direction, generally opposite to said first direction.