| 摘要 |
PROBLEM TO BE SOLVED: To automatically detect the loss of a card and to report it to a managing center. SOLUTION: After the lapse of a fixed time from the start of a timer 23, a portable read/write unit 2 tries to read an ID card 1 and judge the presence/ absence of the IC card 1. When the ID card 1 is lost, the distance between the ID card 1 and the portable read/write unit 2 becomes out of a communicable range. Since data can not be received from the ID card 1, the portable read/ write unit 2 judges that the ID card 1 is lost, and transmits data showing the loss of the ID card 1 to a portable telephone set 3. The portable telephone set 3 originates a call to a managing center 4 and reports the loss of the ID card 1 through a communication network 5 to the managing center 4. |
