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:
Jun. 15, 1999
Filed:
Dec. 31, 1997
William R Vogt, Morris County, NJ (US);
Wells Fargo Alarm Systems, Inc., King of Prussia, PA (US);
Abstract
A security system (40) monitoring displacement between a first, fixed unit (20) and a second, movable unit (21) normally in close proximity to each other. A code generator (51) in the first unit (20) generates a coded electrical signal (Sc) supplied to an optical transducer (24) that converts the signal into an optical signal transmitted at the second unit. A transducer (34) in the second unit receives the transmitted signal, converts it back into an electrical signal now supplied to a code generator (56) in the second unit This generator determines if the electrical signal corresponds to the coded signal. If so, this second code generator generates a second coded electrical signal which is supplied to a transducer (35) in the second unit that converts the signal into an optical signal transmitted back toward the first unit. A transducer (28) in the first unit receives this reply signal and converts it back into an electrical signal. The first code generator now determines if the reply signal supplied corresponds to the second coded signal. Failure of the first unit to either receive the return signals or of the fist code generator to determine the reply signal corresponds to the second coded signal indicates either the units are no longer in close proximity; or, someone is trying to compromise the security system. Either condition constitutes an alarm condition for which an alarm is produced.