摘要 |
A ceiling mounted infrared intrusion detection system achieves 360-degree viewing capability by employing concentric rings of mirrors arranged to view multiple segments within an annular volume of space and focus on a centrally located detector. The rings of mirrors have multiple facets, each of which facets reflects radiation from a segment of space being viewed and focuses the radiation on the detector. The rings are disposed in spaced relationship to one another to provide shorter focal lengths for the mirror facets disposed to view space closest to the detector and a path between the rings through which reflected radiation focused on the detector may pass. the centermost ring is open to permit the detector to view directly therethrough.
|