Electronic indentification system with transponder muting
First Claim
1. An identification system comprising an interrogator and a set of transponders, the interrogator comprising:
- a transmitter arranged to transmit an interrogation signal to the transponders;
a receiver arranged to receive transponder response signals from the transponders;
means for identifying a transponder from data in a corresponding one of the transponder response signals; and
means for indicating a successful identification of the transponder response signal to the identified transponder a predetermined period after the transponder response signal from the identified transponder is received;
each of the transponders comprising;
a receiver arranged to receive the interrogation signal,means for repeatedly transmitting the transponder response signals including data which identifies the transponder,means for muting the transponder in response to receiving the successful identification indication from the interrogator; and
means for inserting a random or pseudo-random interval between the transponder response signals, whereinthe set of transponders contains two or more transponders having a same transponder identity and transmitting the transponder response signals including a same data in response to the interrogation signal.
2 Assignments
0 Petitions
Accused Products
Abstract
An identification system includes an interrogator and a number of transponders. The interrogator includes a transmitter for transmitting an interrogation signal to the transponder, and a receiver for receiving a response signal from the transponder. A micro-processor identifies the transponder from data in the response signal. Each transponder includes a receiving antenna for receiving the interrogation signal, a code generator, a transmitting antenna, and a modulator connected to the code generator. On receipt of the interrogation signal the transponder repeatedly transmits a response signal containing data which identifies the transponder. The interrogator detects successful identification of any transponder and briefly interrupts the interrogation signal to indicate the successful identification. Each transponder includes a logic circuit responsive to a respective interruption in the interrogation signal to cease transmission of its own response signal.
45 Citations
55 Claims
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1. An identification system comprising an interrogator and a set of transponders, the interrogator comprising:
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a transmitter arranged to transmit an interrogation signal to the transponders; a receiver arranged to receive transponder response signals from the transponders; means for identifying a transponder from data in a corresponding one of the transponder response signals; and means for indicating a successful identification of the transponder response signal to the identified transponder a predetermined period after the transponder response signal from the identified transponder is received;
each of the transponders comprising;a receiver arranged to receive the interrogation signal, means for repeatedly transmitting the transponder response signals including data which identifies the transponder, means for muting the transponder in response to receiving the successful identification indication from the interrogator; and means for inserting a random or pseudo-random interval between the transponder response signals, wherein the set of transponders contains two or more transponders having a same transponder identity and transmitting the transponder response signals including a same data in response to the interrogation signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A transponder comprising
means for receiving an interrogation signal; -
means for repeatedly transmitting transponder response signals including data which identifies the transponder; means for inserting a random or pseudo-random interval between transponder response signals; and control means for muting the transponder in response to an indication of successful identification occurring a predetermined period after a corresponding one of the transponder response signals is transmitted, wherein in a set of transponders, two or more transponders having a same transponder identity are arranged to transmit the transponder response signals including a same data in response to the interrogation signal. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
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28. An interrogator for identifying a set of transponders, the interrogator comprising:
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a transmitter arranged to transmit an interrogation signal to the set of transponders; a receiver arranged to receive transponder response signals from the transponders; means for identifying the transponder response signals and for determining a number of transponders; and means for indicating a successful identification to the identified transponder a predetermined period after a corresponding one of the transponder response signals from the identified transponder is received, wherein the identified transponder is arranged to be muted in response to the successful identification, and the set of transponders include at least two transponders having a same transponder identity and transmitting the transponder response signals having a same data in response to the interrogation signal. - View Dependent Claims (29, 30, 31, 32, 43, 44)
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33. An integrated circuit for use in a transponder, the integrated circuit comprising:
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means for repeatedly generating second signals including data which identifies the integrated circuit in response to a first signal; means for inserting one of a random and pseudo-random interval between the second signals; means, responsive to an indication of successful identification from an interrogator, for disabling the means for repeatedly generating second signals, wherein; in a set of integrated circuits, allowing at least two of the integrated circuits to generate the second signals including identical data indicating identical identities for respective ones of the at least two integrated circuits in response to an interrogation signal. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40, 41, 42)
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45. A transponder comprising:
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an integrated circuit; and a receiving antenna formed on a substrate, the integrated circuit comprising; means for repeatedly generating second signals including data which identifies the integrated circuit in response to a first signal; means for inserting one of a random and pseudo-random interval between the second signals; means, responsive to an indication of successful identification from an interrogator, for disabling the means for repeatedly generating second signals, wherein; in a set of transponders having integrated circuits, allowing at least two of the transponders to generate the second signals including identical data indicating identical identities for respective ones of the at least two transponders in response to an interrogation signal. - View Dependent Claims (47)
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46. A transponder comprising:
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an integrated circuit; and a transmitting antenna formed on a substrate, the integrated circuit comprising; means for repeatedly generating second signals including data which identifies the integrated circuit in response to a first signal; means for inserting one of a random and pseudo-random interval between the second signals; means, responsive to an indication of successful identification from an interrogator, for disabling the means for repeatedly generating second signals, wherein; in a set of transponders having integrated circuits, allowing at least two of the transponders to generate the second signals including identical data indicating identical identities for respective ones of the at least two transponders in response to an interrogation signal.
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48. A method for identifying a transponder in an identification system, the method comprising:
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transmitting an interrogation signal to a plurality of transponders from an interrogator; transmitting a transponder response signal from a transponder in response to the interrogation signal, the transponder response signal including data which identifies the transponder; receiving the transponder response signal at the interrogator; identifying the transponder from the data in the transponder response signal; indicating a successful identification of the transponder response signal to the identified transponder a predetermined period after the transponder response signal from the identified transponder is received at the interrogator; and muting the transponder in response to receiving the successful identification indication from the interrogator, wherein at least two transponders of the plurality of transponders have a same transponder identity and transmit transponder response signals including the same transponder identity in response to the interrogator signal, and when the transponder fails to sense a successful indication of the transponder response signal, retransmitting the transponder response signal a random or pseudo-random interval of time after a previous transmission of the transponder response signal. - View Dependent Claims (49, 50, 51, 52, 53, 54, 55)
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Specification