NON-CONTACT IC CARD SYSTEM

摘要

PURPOSE:To eliminate radio wave interference mutually among respective ground machines in a non-contact IC card system. CONSTITUTION:Reference clock generators 1 are provided on the outside of the ground machines 7 provided for respective traffic lanes near the tollgate of a toll road and reference clocks C1 from the generators 1 are supplied to the respective ground machines 7 in common. Also, phase locked loop devices 6 whose input is the reference clocks C1 from the reference clock generators 1 are provided in the respective ground machines 7 and by outputting carrier waves C5 from the phase locked loop devices 6 following the reference clocks C1, the oscillation frequencies of the carrier waves C5 of the respective ground machines 7 become identical.