The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 17, 2001
Filed:
Oct. 13, 2000
Hansjürg Mahler, Hombrechtikon, CH;
Stefan Hegnauer, Dübendorf, CH;
Siemens Building Technologies, AG Cerberus Division, Mannedorf, CH;
Abstract
The infrared detector contains an entrance window for infrared radiation, an infrared sensor with an evaluation circuit and an anti-masking device having an optical transmitter and an optical receiver for detecting phenomena or optical changes immediately in front of the detector and/or changes in the optical properties of the entrance window. The signals of the anti-masking device are evaluated in two channels, wherein one channel responds to temporally limited phenomena or changes and the other channel responds to temporally stable phenomena or changes. A combined evaluation of the signals in the two channels takes place. In the combined evaluation, the channel processing the signals of the infrared sensor is preferably also included. As a result, the infrared detector acquires an increased immunity to false alarms and a higher sensitivity.