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:
Apr. 18, 1989
Filed:
Sep. 01, 1988
Aaron A Galvin, Lexington, MA (US);
Douglas L Mason, Newton Centre, MA (US);
Kenneth J Leff, Halifax, MA (US);
John N Schide, Watertown, MA (US);
Ralph A Giffone, Brighton, MA (US);
ADT, Inc., Parsippany, NJ (US);
Abstract
A controller including a processor is coupled to a transceiver head pair respectively operative as a transmitter and as a receiver of infrared energy to controllably project a beam of infrared energy therebetween through a projected region. The controller is operative to de-sensitize the beam against potential electrically interferring effects present along the beam path. Plural alarm thresholds are operator selectable to provide enhanced confidence detection, and particularized signal indications are provided to readily and quickly identify possible alarm and trouble conditions.