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:
Nov. 05, 2013
Filed:
Jun. 17, 2009
Christian Lehner, St. Florian, AT;
Christian Lehner, St. Florian, AT;
Keba AG, Linz, AT;
Abstract
The invention relates to a method and devices for protecting a reading device () for card-shaped data carriers () against unauthorized evaluation or copying of magnetically encoded data detected in the reading device () for card-shaped data carriers (). To this end, an electromagnetic noise field () is generated by means of a noise field coil (). The use or disposition of the at least one noise field coil () is such that the authorized magnetic field reading head () is also affected by the noise field () of the noise field coil () when the magnetically encoded data of a card-shaped data carrier () is being read. An output or sum signal of the authorized magnetic field reading head () generated from the wanted signal of a card-shaped data carrier () and from the effects of the noise field () is detected. The effect of the noise field () of the noise field coil () in the output or sum signal of the authorized magnetic field reading head () is then compensated or filtered out or the wanted signal is selectively filtered out of the output or sum signal of the authorized magnetic field reading head ().