[54] IC CARD HAVING A FUNCTION TO EXCLUDE ERRONEOUS RECORDING
[75] Inventor: Kunio Fujisaki, Aichi, Japan
[73] Assignee: Hitachi, Ltd., Tokyo, Japan
[21] Appl. No.: 118,603
[22] Filed: Nov. 9,1987
[30] Foreign Application Priority Data
Nov. 10, 1986 [JP] Japan 61-265484
[51] Int. CI.* G06F 15/30
[52] U.S. a 235/379; 235/436;
235/441; 340/825.5; 902/26
[58] Field of Search 902/26, 38; 235/437,
235/441, 492, 379, 436; 340/825.3, 825.5
[56] References Cited
U.S. PATENT DOCUMENTS
4,683,372 7/1987 Matsumoto 902/26 X
4,736,094 4/1988 Yoshida 235/379
4,780,602 10/1988 Kawana et al 235/492 X
FOREIGN PATENT DOCUMENTS 59-11478 1/1984 Japan .
An IC card system comprises an IC card, each card including a microprocessor, a communication interface, a power supply interface, and memories such as RAM, ROM and EEPROM, and an external device such as a terminal. The terminal functions to supply electric power and send commands to the IC card, and includes a card reader/writer effecting data processing for transactions. The commands include a start command and an end command for the transaction data processing for the IC card connected therewith, and the IC card comprises a validity data flag table within the EEPROM. When a start command is received, the flag table records the validity flag in an invalid state and holds such state as long as an end command is not received.
7 Claims, 7 Drawing Sheets
