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:
Mar. 30, 1999
Filed:
Mar. 04, 1996
Applicant:
Inventors:
Assignee:
Siemens Aktiengesellschaft, Munich, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ; B60R / ; B60R / ; G08C / ;
U.S. Cl.
CPC ...
34082531 ; 4551921 ; 307 102 ; 307 105 ; 340825 ; 340 72 ;
Abstract
In an anti-theft system for a motor vehicle, an oscillating circuit of a transceiver in the motor vehicle is modulated with code information of a portable transponder. A demodulator detects the code information and carries it onward to a computer unit, where it is checked for authorization. Component tolerance or temperature changes can mean that initially no code information will be demodulated, despite a properly functioning transponder. According to the invention, the frequency of the modulated oscillation is then measured and reregulated to a command frequency.