Cerberus Ag

John R Baldwin

William S Kahl

William G Kahl, Jr

A ceiling mounted passive infrared detector has an enclosure arranged for mounting to ceiling, a downwardly pointing infrared detecting element within the enclosure, a first multifaceted pyramidal mirror having an apex pointing upwardly toward the detecting element and a plurality of focusing lenses, one for each facet of the mirror and mounted between the base of the pyramidal mirror and the periphery of the enclosure to focus infrared radiation onto the detecting element directly and via reflection in the pyramidal mirror. A further embodiment includes the enclosure wherein the lenses are disposed on the plane immediately above the apex of the mirror so that radiation will be reflected off the mirror and refracted by the lenses onto the detecting element.

Ceiling mounted passive infrared intrusion detector with pyramidal mirror

A ceiling mounted passive infrared intrusion detector includes a window which has an exterior surface with ridges formed of intersecting planes, which are arranged to provide internal reflection of radiation received from selected angles with respect to the optical axis of the device and to deflect such radiation into a direction parallel to the optical axis. Focusing means arranged as part of the detector focuses the parallel infrared radiation onto a detecting element within the device.

Ceiling mounted passive infrared intrusion detector with prismatic window

A passive infrared intrusion detector is arranged for mounting to the ceiling of a room to be protected. Infrared radiation from points within the room is focused onto an infrared sensing element by a multi-segment dome-shaped lens. The multi-segment lens in a preferred embodiment has central, downwardly facing beams of infrared sensitivity and other beams of infrared sensitivity at multiple azimuth angles at selected elevation angles.

Ceiling mounted passive infrared intrusion detector with dome shaped lens

A passive infrared intrustion detector is provided with a lens which has a plurality of first lens segments, each for focusing infrared radiation from various beams of sensitivity onto an infrared detecting element. Associated with each of the first lens segments is a second lens segment, with a displaced lens center, which serves to focus light originating within the detector device into a radiated beam, which corresponds in space to the region of sensitivity of the infrared beams.

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Danbury, CT, United States of America

John R Baldwin