Rechargeable prepaid memory card with both unit and page counters
US5264689A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 7, 1992 |
| Grant date | Nov 23, 1993 |
| Priority date | — |
| Expiry date | Jan 7, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F7/02
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The disclosure concerns memory cards and, more particularly, cards that are used as means of prepayment in installations for the dispensing of products and services. It is proposed to make the memory rechargeable by means of a credit counter, incrementable from outside the card, and a comparator which compares the content of this counter with that of a page counter. The page counter records the number of pages of P accounting units already used up. A no more credit signal is emitted on an external terminal when the content of the page counter reaches the content of the credit counter. A security system against the fraudulent recharging of the card is set up by an algorithm bringing into play the content of the credit counter and an identification number contained in the card.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.