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. 28, 2002
Filed:
Aug. 17, 2001
Patrick A. Banas, Sterling Heights, MI (US);
Siemens Automotive Corporation, Auburn Hills, MI (US);
Abstract
A system for preventing unauthorized access to a vehicle having a passive entry system uses a bi-directional radio frequency, or RF-RF, signal. When using a RF-RF signal system, the signal from vehicle to a driver's ID device is non-directional and not significantly distance limited. Consequently, a thief may be able to activate the entry system and gain access to the vehicle when the driver's ID device is simply within range. The inventive passive entry system interrogates the ID device periodically following parking and locking of the vehicle. The signal strength levels received by the vehicle from the ID device are stored and a signal strength threshold level is computed. Upon a request for entry to the vehicle, a current signal strength level is compared to the signal strength threshold level. Based on that comparison, it is determined whether the request is valid or unauthorized. If the request for entry is deemed unauthorized, then access to the vehicle is not granted.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile