For automated communication in a limited acquisition space, for example in order to identify or check an access authorization, use is made of active data supports which comprise a transmitter (15), a receiver (16), a read-write memory, an electric clock, a computer, a display and a power source (7)....http://www.google.fr/patents/US5202550?utm_source=gb-gplus-shareBrevet US5202550 - Device for machine communication in data transmission
Device for machine communication in data transmission
