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:
Aug. 04, 1998
Filed:
Apr. 21, 1997
Scott O Campbell, Canton, MI (US);
Lawrence Peter Kirk, Canton, MI (US);
David Philip Laude, Colorado Springs, CO (US);
Luke Aaron Perkins, Security, CO (US);
William David Treharne, Farmington Hills, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A security system utilizing a key-mounted transponder achieves fast and accurate charging of the transponder by using a frequency search and acquisition phase which attempts partial charging pulses at a plurality of spaced frequencies. After a successful partial charging, a frequency calibration signal is received from the transponder which provides a reference in the transceiver for producing a pulse for fully charging the transponder. Frequency search and acquisition allows robust system operation while using low cost and low tolerance parts.