Enhanced identification system
First Claim
1. An identification system comprisinga reader including a transmitter for transmitting a rf continuous wave reader signal at a pre-selected frequency;
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6 Assignments
0 Petitions
Accused Products
Abstract
A method and an identification system used for communicating between a reader and a plurality of transponders. The reader has a transmitter for transmitting a signal and each transponder includes a receiver for receiving the reader signal and a transmitter for generating a transponder signal. When the reader recognizes a transponder signal from one of the transponders it immediately issues a mute instruction, muting all other active transponders and passing control to the said transponder, without the need for a specifically timed acknowledgement to the said controlling transponder. The reader may issue a single disable/wakeup instruction which disables the controlling transponder returning control to the reader and reactivated all muted (but not disabled) transponders.
59 Citations
24 Claims
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1. An identification system comprising
a reader including a transmitter for transmitting a rf continuous wave reader signal at a pre-selected frequency; - and
a plurality of transponders, each transponder including a receiver for receiving the reader signal and a transmitter for generating a transponder signal, whereby upon recognising a transponder signal from a said transponder the reader immediately issues a mute instruction, muting all other active transponders and passing control to the said transponder, without the need for a specifically timed acknowledgement to the said controlling transponder, wherein the mute instruction comprises a modulation of the reader signal whilst the reader signal is maintained at the said pre-selected frequency. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method of identifying a plurality of transponders comprising:
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transmitting a reader signal from a reader, the reader signal comprising a rf continuous wave signal at a pre-selected frequency, receiving the reader signal, in each transponder; and recognizing in the reader a transponder signal transmitted from a transponder and immediately issuing a mute instruction from the reader, muting all other active transponders and passing control to the said transponder, without the need for a specifically timed acknowledgement to the said controlling transponder, wherein the mute instruction comprises a modulation of the reader signal whilst the reader signal is maintained at the said pre-selected frequency. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A transponder comprising:
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receiver means for receiving a reader signal at a pre-selected frequency, transmission means for transmitting a transponder signal containing data which identifies the transponder, whereby in a set of transponders, two or more transponders may transmit their transponder response signals in response to receiving the reader signal; and control means whereby on recognizing a mute instruction in the reader signal all other active transponders in the set but one are muted and control is passed to said one transponder, without the need for a specifically timed acknowledgement to the said controlling transponder, wherein the mute instruction comprises a modulation of the reader signal whilst the reader signal is maintained at the said pre-selected frequency. - View Dependent Claims (14, 15, 16, 17, 18)
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19. An integrated circuit for use in a transponder, comprising:
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receiver means for receiving a reader signal at a pre-selected frequency, transmission means for transmitting a transponder signal containing data which identifies the transponder, whereby in a set of transponders, two or more transponders may transmit their transponder response signals in response to receiving the reader signal, and control means whereby on recognizing a mute instruction in the reader signal all other active transponders in the set but one are muted and control is passed to said one transponder, without the need for a specifically timed acknowledgement to the said controlling transponder, wherein the mute instruction comprises a modulation of the reader signal whilst the reader signal is maintained at the said pre-selected frequency. - View Dependent Claims (20, 21, 22, 23, 24)
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Specification