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. 14, 2005
Filed:
Jun. 18, 2004
Bruno Charrat, Aix en Provence, FR;
Bruno Charrat, Aix en Provence, FR;
Inside Contactless, Aix-en-Provence, FR;
Abstract
A contactless integrated circuit reader includes an antenna coil for emitting an oscillating magnetic field, and circuitry for detecting the presence of a contactless integrated circuit within a communication perimeter of the reader without receiving an identification message. The detection circuitry include circuitry for emitting short magnetic field pulses, circuitry for extracting from the antenna coil an envelope signal having envelope pulses corresponding to the magnetic field pulses, and circuitry for monitoring the amplitude of the envelope pulses, arranged for detecting a variation in the amplitude of the envelope pulses representative of the entry of the contactless integrated circuit into the communication perimeter of the reader.