Non-contact type IC card
US5378887A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 14, 1993 |
| Grant date | Jan 3, 1995 |
| Priority date | — |
| Expiry date | Jan 14, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG07F7/082
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
In a non-contact type IC card, a re-access inhibition time setting circuit 12 sets a re-access inhibition period of time for inhibiting the re-access for a fixed period of time after an operation of a main circuit 16 is finished. This prevents a double write operation of history in the card due to the re-access in a short period of time. Moreover, two areas 321 and 322 are disposed in a memory 32 to write data alternately in these areas. In a read operation, when data of one of the areas is destroyed, the normal data in the other area is read; whereas, when each data is normal, the data last recorded is read. Consequently, the disabled state of the read operation due to wrong data can be prevented.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.