DEVICE FOR THE CONTACTLESS TWO-WAY TRANSMISSION OF DATA AND POWER BETWEEN A READER AND A CHIP-CARD

摘要

The system comprises a first optical path (11, 26-27, 28) for transmission of power and data from the reader (10) to the chip-card (20) which comprises at least one modulated light source (11) which resides in the reader and a demodulating receiver (26) which resides in the chip-card, and a second magnetic path (17, 23, TR) for the transmission of data only, which is active at least in the direction from the chip-card (20) to the reader (10) and comprises a primary coil (17), which resides in the reader and is supplied with a carrier current (i1), and a secondary coil (23), which resides in the chip-card (20) and is controlled by local modulation means (CPU-TR); said primary coil and said secondary coil being coupled by mutual magnetic inductance (L1-2) so that the carrier current of the primary coil (17) varies so as to supply a useful signal to the reader (10) in a manner which matches the modulation to which the secondary coil (23) is subjected locally.