| 摘要 |
PROBLEM TO BE SOLVED: To improve the space efficiency in handling and to improve the recovery efficiency by making the external shape of a casing nearly disklike so that it is easy to roll, and providing adjustment amount information corresponding to every face amount kind. SOLUTION: A prepaid coin 10 has a nearly disklike resin-made casing 20, wherein an IC chip 30, an antenna 40, etc., are enclosed. The IC chip 30 is equipped with an adjustment amount information memory and a balance information memory, and the adjustment amount information memory stores adjustment amount information set corresponding to the kind of the prepaid coin 10 and the balance information memory stores balance information updated according to the balance of the prepaid coil 10. A storage control circuit is connected to the adjustment amount information memory and balance information memory and a subtracting circuit is connected to the storage control circuit. The storage control circuit updates the balance information read out of the balance information memory by subtraction and writes the updated balance information back to the balance information memory. |
