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. 13, 1990
Filed:
Dec. 18, 1987
Applicant:
Inventor:
Christian Guion, Verrieres le Buisson, FR;
Assignee:
Schlumberger Industries, Montrouge, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06K / ;
U.S. Cl.
CPC ...
235380 ; 235436 ; 235449 ; 902-4 ;
Abstract
The system comprises memory cards and card readers. The card memories (MEM) include validation memory points V.sub.j and credit memory points C.sub.i,j. The addresses of the validation points V.sub.j and the addresses of the associated credit point C.sub.i,j are defined by a reference table (TRR) and a permutation table (TP) which make use of a data item (Z.sub.F) which is specific to the card.