| 摘要 |
PURPOSE:To realize the common use between two IC card signal transmitting/ receiving circuits with no change by providing two terminals regardless of a signal 1-wire type or a signal 2-wire type to connect these terminals to an IC card and using both terminals as the transmitting/receiving signal lines with a resistance put between both terminals. CONSTITUTION:The 1st and 2nd terminals 4 and 5 are provided for transfer of signals to an IC card 6 and a resistance 3 is connected between both terminals 4 and 5. Then the logical level of the information to be transmitted is shifted from the prescribed value of the logical level within the card 6 by an extent in response to the voltage drop of the resistance 3 for execution of transmission or reception. In such a way, both terminals 4 and 5 are used regardless of a signal 1-wire type or a signal 2-wire type and connected to the card 6. Then both terminals 4 and 5 are used as the transmitting/receiving signal lines with the resistance 3 put between both terminals. Thus the IC card signal transmitting/receiving circuits 2 and 20 are used in common with no change regardless of a single or two signal lines of the card 6.
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