| 摘要 |
PURPOSE:To execute the electromotive force of a device to be identified and the transmission of an identification signal to a reader by a pair of transmitting and receiving circuits by executing the transmission of the identification signal as the change of load of the leader to a transmitting means. CONSTITUTION:When high frequency is oscillated from an oscillation circuit 1 in the reader under the status that the reader and the device to be identified are adjacently arranged, a part of the energy is discharged from a coil 3 in a tuning circuit A. When the coils 3, 8 in the tuning circuits A, B are tightly coupled, a high frequency current is generated in the tuning circuit B of the device to be identified. When the terminal voltage of a capacitor 12 reaches a prescribed value by the current, a code generator 13 is driven. The electrostatic capacity of a variable capacity element 15 is changed in accordance with the output waveform of the code generator 13 and the resonance frequency of the tuning circuit B is varied. The same waveform as the output of the code generator 13 is generated from the output of a detecting circuit 4 and displayed on a display part 6 through a decoder 5 to identify the device to be identified.
|
