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:
May. 31, 1994
Filed:
Apr. 02, 1992
Milton O Smith, Bothell, WA (US);
Orca Technology, Inc., Seattle, WA (US);
Abstract
A battery-powered infrared sensor security system capable of operating on a single set of batteries for a minimum of one year. The system is connected to a telephone line and employs a bidirectional dual-tone multiple frequency (DTMF) tone generator/receiver to allow communication to and from a remote location. The system status may be checked from the remote location and certain system parameters may be varied from the remote location. The system uses a Fresnel lens arrangement and a pair of infrared sensors to provide a substantially uniform field of coverage of 180.degree.. The system also uses real time digital analysis of the output signals from the infrared sensors. The digital analysis uses time sequence analysis of the output signals, performs variance measurements between the current measurement of the infrared sensor signals and the stored time sequence, coherence measurements between the two sensors, and can compare measured amplitude spectra to predefined signature spectra entered by the user.