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:
Jan. 30, 2001
Filed:
Dec. 08, 1998
Ian MacDonald Green, London, GB;
Simon Nicholas Murray Willcock, High Wycombe, GB;
Central Research Laboratories Limited, Middlesex, GB;
Abstract
A method of identifying a data carrier such as a credit card, benefit card, access control card, identity card or stored value card, carrying data in the form of a plurality of rational number in a sequence, successive numbers having a marker between them, comprises a) measuring the distance from a fixed point on the data carrier to a given part of a marker, b) dividing this distance by the distance between corresponding give parts of successive markers, thereby obtaining a rational number, and c) subtracting this rational number from the number in the sequence adjacent the marker in a given direction, thereby obtaining a further rational number which is capable of identifying the data carrier uniquely.