Memory tag and a reader
First Claim
1. A memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a reader signal from a reader, the magnitude of the output signal being dependent on the magnitude of the reader signal, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal which is configured to cause the reader to increase the magnitude of the reader signal from a first level to a second relatively high level, and when the magnitude of the output signal is relatively high as a result of the tag receiving the second relatively high magnitude reader signal from the reader, the detector module is operable to cause the tag to move to an operating mode.
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Accused Products
Abstract
A memory tag comprising a resonant circuit part, a memory, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a signal from a reader, the amplitude of the output signal dependent on the magnitude of the signal from the reader, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal, and when the magnitude of the output signal is relatively high, the detector module connects the memory to the resonant circuit part.
22 Citations
28 Claims
- 1. A memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate an output signal in response to a reader signal from a reader, the magnitude of the output signal being dependent on the magnitude of the reader signal, the detector module being responsive to the magnitude of the output signal such that, when the magnitude of the output signal is relatively low, the detector module causes the output generator module to transmit an identifier signal which is configured to cause the reader to increase the magnitude of the reader signal from a first level to a second relatively high level, and when the magnitude of the output signal is relatively high as a result of the tag receiving the second relatively high magnitude reader signal from the reader, the detector module is operable to cause the tag to move to an operating mode.
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8. A memory tag comprising a resonant circuit part, a detector module, an output generator module and a memory, the resonant circuit being operable to generate an output signal in response to a reader signal from a reader, the magnitude of the output signal being dependent on the magnitude of the reader signal, the detector module being operable in response to the output signal such that when the magnitude of the output signal received by the memory tag is relatively low, the detector module causes the output generator module to transmit an identifier signal configured to induce the reader to increase the magnitude of the reader signal from a normal finite level to a higher level, and when the magnitude of the output signal is relatively high in response to the magnitude of the reader signal being increased to the higher level, the detector module is operable to connect the memory to the resonant circuit part.
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9. A reader to read a memory tag, the reader being operable to transmit a reader signal to a memory tag, the reader further being operable to receive a signal from a memory tag, the reader:
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being operable to transmit the reader signal to the memory tag at a first, relatively low power, and in response to an identifier signal being issued from the memory tag in response to receipt of the reader signal having the first relatively low power, and being operable to transmit a reader signal to the memory tag at a second, relatively high power whereby the reader is switched from a low power search mode to a high power read mode. - View Dependent Claims (10, 11, 12, 13)
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14. A reader to read a memory tag, the reader comprising a resonant circuit part, an interrogator, and an identifier signal module, the interrogator module being operable to transmit a reader signal at a first, relatively low power to a memory tag, receive a signal from the memory tag which is generated by the memory tag in response to receipt of the first, relatively low power reader signal, and pass the received signal to the identifier signal module, the identifier signal module being operable to identify the identifier signal and generate an instruction to the interrogator module to generate a reader signal at a second, relatively high power.
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15. A system comprising a memory tag and a reader, the memory tag having a resonant circuit part, a detector module, an output generator module and a memory holding data, the reader comprising a resonant circuit part operable to transmit a reader signal to the memory tag and receive a signal from the memory tag, the reader being operable to transmit a reader signal to the memory tag at a first relatively low power wherein,
the resonant circuit part of the memory tag, in response to the reader signal, generates an output signal having a first, relatively low magnitude, the detector module is responsive to the first relatively low magnitude of the output signal to cause the output generator module to transmit an identifier signal, the reader is operable to receive the identifier signal from the memory tag and identify the identifier signal, and generate a reader signal at a second, relatively high power, the resonant circuit part of the tag is operable to generate an output signal having a second, relatively high magnitude, the detector module being responsive to the output signal having a second, relatively high magnitude to connect the memory to the resonant circuit part, and the memory tag is operable to send a signal to the reader to transmit the data held in the memory to the reader.
- 16. A method of operating a memory tag comprising the steps of detecting a reader signal received from a reader, and, when the magnitude of the reader signal received by the tag is relatively low, transmitting an output identifier signal from the tag to the reader to induce the reader to increase the power of the reader signal, and when the magnitude of the reader signal received by the tag is relatively high as a result of the reader receiving the output identifier signal, moving to an operating mode by using the received reader signal with the relatively high magnitude, to energize the memory tag.
- 18. A memory tag comprising a resonant circuit part, a detector module and an output generator module, the resonant circuit part being operable to generate a first relatively low magnitude output signal and a second relatively high magnitude output signal respectively in response to a first reader signal and a second reader signal which are respectively issued from a reader at first and second power levels, the magnitude of the first output signal being variable with the magnitude of the first reader signal which is lower in power than the second reader signal, the detector module being responsive to the relatively low magnitude of the first output signal such that the detector module transmits an identifier signal which is configured to induce the reader to issue the second relatively high power level reader signal, and in response to the second output signal, which is induced by the second relatively high power level reader signal, the detector module is operable to cause the tag to move to an operating mode.
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25. A method of operating a reader for reading a memory tag comprising:
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generating a reader signal normally having a first, relatively low power during a low power search mode, detecting an identifier signal from a memory tag which is produced by the memory tag in response to receipt of the reader signal having the first relatively low power, and inducing a high-power read mode by generating, in response to detection of the identifier signal, a reader signal at a second, relatively high power to excite the memory tag into an operating mode wherein data can be transmitted from the memory tag and read by the reader. - View Dependent Claims (26, 27, 28)
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Specification