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:
Jul. 18, 1995
Filed:
Jul. 26, 1993
Applicant:
Inventors:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
235380 ; 371 62 ; 235438 ; 235492 ;
Abstract
To counter illicit prevention of the invalidation of a smart card in a pay television network, for example when the period of validity for the card has expired, a verification of the card reader's ability to write to the card's memory is made. This verification consists in periodically sending a data item to be stored in the card. A counter on the card is reset by the writing voltage of the card's storage. In the event the writing voltage does not reach the counter, the counter's overflow output is connected to a read inhibition circuit which blocks functions of the card.