Presence and data labels
First Claim
1. A system for detecting presence of and for communicating with one or more electronic coded labels, the or each coded label including a presence signalling antenna, a label circuit and a data communications antenna, said system including:
- presence detection means for creating a presence detection electromagnetic field;
data communications means for creating an interrogation electromagnetic field;
wherein the or each label circuit is adapted to operate in a first mode when the electromagnetic field to which the associated label is exposed is at a first power level, said first mode being that of a linear circuit with an impedance dependent upon frequency, and the or each label circuit is adapted to operate in a second mode when the electromagnetic field to which the associated label is exposed is at a second power level, said second mode being that of a non-linear circuit with behaviour dependent upon time.
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Accused Products
Abstract
A system for detecting presence of and for communicating with an electronic coded label. The coded label includes a presence signaling antenna, a label circuit and a data communications antenna. The system includes presence detection means for creating a presence detection electromagnetic field and data communications means for creating an interrogation electromagnetic field. The label circuit is adapted to operate in a first mode when the electromagnetic field to which the label is exposed is at a first power level, said first mode being that of a linear circuit with an impedance dependent upon frequency. The label circuit is adapted to operate in a second mode when the electromagnetic field to which the label is exposed is at a second power level, said second mode being that of a non-linear circuit with behavior dependent upon time.
63 Citations
52 Claims
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1. A system for detecting presence of and for communicating with one or more electronic coded labels, the or each coded label including a presence signalling antenna, a label circuit and a data communications antenna, said system including:
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presence detection means for creating a presence detection electromagnetic field; data communications means for creating an interrogation electromagnetic field; wherein the or each label circuit is adapted to operate in a first mode when the electromagnetic field to which the associated label is exposed is at a first power level, said first mode being that of a linear circuit with an impedance dependent upon frequency, and the or each label circuit is adapted to operate in a second mode when the electromagnetic field to which the associated label is exposed is at a second power level, said second mode being that of a non-linear circuit with behaviour dependent upon time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51)
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52. An electronic coded label for use with a system for detecting presence thereof and for communicating therewith, said label including a presence signalling antenna, a label circuit and a data communications antenna, wherein said label circuit is adapted to operate in a first mode when an electromagnetic field to which said label is exposed by said system is at a first power level, said first mode being that of a linear circuit with an impedance dependent upon frequency, and said label circuit is adapted to operate in a second mode when the electromagnetic field to which said label is exposed by said system is at a second power level, said second mode being that of a non-linear circuit with behaviour dependent upon time.
Specification