SPATIAL SIGNAL TRANSMITTER

PURPOSE:To enable power source-free card application with the elimination of a power source on the transmitting side, by receiving a high frequency magnetic field from a receiving coil with a transmitting coil to be used as power source with the rectification thereof. CONSTITUTION:A spatial signal transmission is performed with an electromagnetic coupling between a transmitter coil 16 and a coil 21 on the receiver side. As an oscillation circuit 27 on the side of a receiver 5 oscillates at a frequency of 20kHz for instance, the receiving coil 21 is driven through a coil driving circuit 28, which causes the receiving coil 21 to release a high frequency magnetic field of 20kHz to a space. The magnetic field released is received with a transmitting coil 16, further rectified with a rectifier circuit 19 and, then, stored or turned to a constant voltage with a power source circuit 20. A power is supplied to each circuit of a transmitter 2 from the time when a fixed amount of power is stored in the power source circuit to start operation as transmitter.