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:
Jan. 13, 1987
Filed:
Nov. 08, 1983
Aaron A Galvin, Lexington, MA (US);
James B Edson, Concord, MA (US);
John K Guscott, Lynnfield, MA (US);
American District Telegraph Company, New York, NY (US);
Abstract
The motion detector of the present invention, together with associated AC switching circuitry form a lighting control system which turns on room lights when the room is occupied, and extinguishes the lights when unoccupied. The detector sensitivity or threshold is adjusted in response to the previously detected conditions, providing reliable indication of both entry and continued presence in the controlled area, and producing few false alarms. The present embodiment of the invention has two threshold levels of detection, the higher level being used to detect initial entry into the room. After entry is detected, the motion detector lowers the threshold to detect the weaker signals usually occurring for continued presence in the area of the detector. When the occupant leaves the area, the motion detector threshold or sensitivity returns to the original value after a timeout period.