| 摘要 |
PROBLEM TO BE SOLVED: To provide an IC card reader-writer which applies proper voltage to an IC card without applying higher voltage than needed by measuring the resistance value of pull-up resistance of the IC card and applying voltage decided based on the resistance value to the IC card. SOLUTION: In this card reader-writer 1, when an IC card 2 is inserted, a controller 11 switches both switches A 15 and B 16 to a resistance measuring part 12 side. The part 12 measures resistance value of a pull-up resistance 22 between a terminal 23-1 connected to a terminal 19-1 and a terminal 23-2 connected to a terminal 19-2. The controller 11 instructs voltage value to be fed to a power feeding part 13 based on the resistance value of the measured pull-up resistance 22 and the part 13 feeds power to the card 2 with instructed voltage. And, the switch A 15 is changed to the part 13 side and the switch B 16 is changed to a communication part 14 side. |
