CONFIRMATION OF PRESENCE OF ELECTROMAGNETIC TRANSPONDER IN FIELD OF READ MACHINE

摘要

PROBLEM TO BE SOLVED: To provide a novel control method for a read/write terminal that unsharpens the read/write terminal against a demodulation gap of data received from a transponder entering the field of the read/write terminal. SOLUTION: This invention provides the method for controlling the terminal generating an electromagnetic field that is provided with a circuit to control the phase of a signal from an oscillating circuit and uses a signal to oscillate the oscillation circuit while including a method for comparing a current variable linked to current of the oscillation circuit and (voltage applied to the oscillation circuit with a prescribed value and for detecting the presence of the transponder in the electromagnetic field.