Siemens Building Technologies, Inc.

Siemens Building Technologies Ag

Kurt M&uuml;ller

Peter Kunz

Martin Allemann

Dieter Wieser

Markus Loepfe

The passive infrared detector contains a heat-sensitive sensor and a focusing device for focusing thermal rays incident on the detector from the room under surveillance onto the sensor. The focusing device has focusing elements for surveillance regions having different positions in the room under surveillance. Each focusing element comprises a number of sub-elements, with the result that the surveillance regions are split up vertically into subzones having slightly different elevation. In a majority of the surveillance regions, the subzones overlap at most only slightly. Human being and animals are distinguished by the amplitude of the sensor signal which is proportional to the number of subzones interrupted by the object in the room under surveillance. The number of sub-elements and correspondingly the number of subzones increases with decreasing radial distance of the respective surveillance region from the detector.

Passive infrared detector

A detector device for detecting the presence of airborne particles such as smoke includes a light source, an optical bridge, a measurement path, a reference path, a measurement receiver and a reference receiver. The optical bridge, in addition to the light source and the measurement and reference receivers, are the only optical elements of the detector device. The optical bridge includes two circular apertures arranged downstream of the light source along the radiation path. The light source is arranged in a chamber having an air reservoir, whose surface area is substantially greater than that of the light source. A temperature drift curve is determined by heating the light source and storing the detector signal at different temperatures.

Growing community of inventors

Männedorf, Switzerland

Kurt Müller

Growing community of inventors

Männedorf, Switzerland

Kurt M&uuml;ller

Kurt Müller