Transaction system
First Claim
1. A transaction 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;
means for transmitting data from the terminal to the token via a modulated carrier signal; and
means for transmitting data from the token to the terminal by modulation of the level of the carrier signal at the terminal by the token as it draws power from the terminal.
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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 drawn 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manner when it is brought into the proximity of a terminal, and for providing an orderly shut down when the token is withdrawn.
82 Citations
33 Claims
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1. A transaction 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;
means for transmitting data from the terminal to the token via a modulated carrier signal; and
means for transmitting data from the token to the terminal by modulation of the level of the carrier signal at the terminal by the token as it draws power from the terminal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 33)
- a token having an on-board data processing capability;
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17. A transaction system, comprising:
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a terminal which includes a first tuned circuit having a first inductor, first means, connected to the first tuned circuit, for modulating data to be transmitted by the first inductor, and second means, connected to the first tuned circuit, for detecting data received by the first inductor; and a token which includes a second tuned circuit having a second inductor which can be inductively coupled to the first inductor, a third means, connected to the second tuned circuit, for demodulating data received by the second inductor, fourth means, connected to the second tuned circuit, for selectively varying a predetermined characteristic of the second tuned circuit in order to transmit data to the first inductor, and fifth means, connected to the second tuned circuit, for receiving energy from the first inductor to power circuitry included in the token. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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26. A token for use with a terminal which includes a first tuned circuit having a first inductor, first means connected to the first tuned circuit for modulating data to be transmitted by the first inductor, and second means connected to the first tuned circuit for detecting data received by the first inductor, said token comprising:
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a second tuned circuit having a second inductor which can be inductively coupled to the first inductor; third means, connected to the second tuned circuit, for demodulating data received by the second inductor; fourth means, connected to the second inductor, for selectively varying a predetermined characteristic of the second tuned circuit in order to transmit data to the first inductor; and fifth means, connected to the second tuned circuit, for receiving energy from the first inductor to power circuitry included in the token. - View Dependent Claims (27, 28, 29)
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30. A terminal for use with a token which includes a first tuned circuit having a first inductor, first means connected to the first tuned circuit for demodulating data received by the first inductor, second means connected to the first tuned circuit for selectively varying a predetermined characteristic of the first tuned circuit in order to transmit data, and third means connected to the first tuned circuit for receiving energy to power circuitry included in the token, said terminal comprising:
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a second tuned circuit having a second inductor to which the first inductor can be inductively coupled; fourth means, connected to the second tuned circuit, for modulating data to be transmitted by the second inductor, wherein the data to be transmitted by the second inductor is digital data in serial form and has first and second logical levels, and wherein the fourth means includes means for applying a first signal across the second tuned circuit when the data to be transmitted by the second inductor is at the first logical level and for applying a second signal across the second tuned circuit when the data to be transmitted is at the second logical level, the first signal having a first frequency and the second signal having a second frequency that is different from the first frequency, the first and second frequencies being selected so that the signal level across the second tuned circuit is substantially constant regardless of whether the data to be transmitted by the second inductor is at the first logical level or the second logical level; and fifth means, connected to the second tuned circuit, for detecting data received by the second inductor, wherein the signal level across the second inductor varies when data is transmitted to the second inductor, and wherein the fifth means includes means for sensing level changes across the second tuned circuit. - View Dependent Claims (31, 32)
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Specification