An intelligent card has a calculation function and a card holder collation function, and is formed to have the same size as that of a credit card. With the collation function, numeral data input from a key input section of the card is collated with identification data prestored in an internal integrated...http://www.google.fr/patents/US4918631?utm_source=gb-gplus-shareBrevet US4918631 - Compact type electronic information card
