Transaction system
First Claim
1. A transmission system including a terminal;
- a token having an on-board data processing capability;
means for inductively coupling the token with the terminal to permit data communication therebetween and means associated with the terminal for transmitting a carrier signal and for detecting a variation in the power demand on the carrier signal which is indicative of the presence of an inductively coupled token.
1 Assignment
0 Petitions
Accused Products
Abstract
A transaction system enables a portable token to co-operate with a fixed terminal. The token is inductively coupled to the terminal, and receives data from the terminal via a frequency modulated carrier signal. Data is sent from the token to the terminal by amplitude modulation of the carrier signal from the terminal, i.e. by modulating the power driven by the token from the terminal. The power needed to energize the on-board processing capability of the token is also obtained from the terminal via the inductive coupling. The token includes an arrangement for commencing processor operation in an orderly manner when it is brought into the proximity of the terminal, and for providing an orderly shut down when the token is withdrawn.
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Citations
7 Claims
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1. A transmission system including a terminal;
- a token having an on-board data processing capability;
means for inductively coupling the token with the terminal to permit data communication therebetween and means associated with the terminal for transmitting a carrier signal and for detecting a variation in the power demand on the carrier signal which is indicative of the presence of an inductively coupled token. - View Dependent Claims (2, 3, 4)
- a token having an on-board data processing capability;
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5. A terminal for use with a token having an inductor and circuitry connected to the inductor, comprising:
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another inductor, with which the inductor of a token can be inductively coupled; first means, connected to the another inductor, for communicating with the circuitry of a token via the inductor of the token; second means for generating a power demand signal across the another inductor; and third means for detecting whether the another inductor is inductively coupled to the inductor of a token, the third means including means connected to the another inductor for monitoring the power demand signal generated across the another inductor by the second means to detect a variation in the power demand on the signal. - View Dependent Claims (6, 7)
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Specification