Object identification system
First Claim
1. An object identification system comprising:
- a transceiver having a first signal detection sensitivity and including means for transmitting a write signal; and
a transponder having a second signal detection sensitivity less than said first sensitivity, the transponder includingmeans for receiving and detecting said write signal,a memory device for storing an identification code of said transponder, said identification code including bits able to have a plurality of logical states,means for creating an identification signal representative of said identification code such that said identification signal is modulated by the logical state of said bits;
said transceiver further comprising means for receiving and interpreting said identification signal,said transponder further comprisinga variable code generator, andmeans for writing in said memory device, in response to the detection of said write signal, a variable code from said variable code generator such that said variable code constitutes at least a part of said identification code.
1 Assignment
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Accused Products
Abstract
An object identification system comprises a transceiver (1) and a transponder (30) including memories (33,34) for storing an identification code identifying the transponder. Circuits (35, 36, 37, 38) generate an identification signal representative of the identification code such that the identification signal is modulated by bits of the identification code. Circuits (8, 9, 10, 11, 12) of the transceiver receive and interpret the identification signal. The transponder includes a variable code generator (32) and a controller (31) for controlling the writing of the variable code into memory (33) so that the variable code constitutes part of the identification code. The variable code may be a random or pseudo-random code.
32 Citations
22 Claims
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1. An object identification system comprising:
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a transceiver having a first signal detection sensitivity and including means for transmitting a write signal; and a transponder having a second signal detection sensitivity less than said first sensitivity, the transponder including means for receiving and detecting said write signal, a memory device for storing an identification code of said transponder, said identification code including bits able to have a plurality of logical states, means for creating an identification signal representative of said identification code such that said identification signal is modulated by the logical state of said bits; said transceiver further comprising means for receiving and interpreting said identification signal, said transponder further comprising a variable code generator, and means for writing in said memory device, in response to the detection of said write signal, a variable code from said variable code generator such that said variable code constitutes at least a part of said identification code. - View Dependent Claims (2, 3, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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4. An object identification system comprising:
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a transceiver having a first signal detection sensitivity and including means for transmitting a write signal; and a transponder having a second signal detection sensitivity less than said first sensitivity, the transponder including means for receiving and detecting said write signal, memory device for storing an identification code of said transponder, said identification code including bits able to have a plurality of logical states, and means for creating an identification signal representative of said identification code such that said identification signal is modulated by the logical state of said bits; said transceiver further comprising means for receiving and interpreting said identification signal; said transponder further comprising a variable code generator, means for writing in said memory device, in response to the detection of said write signal, a variable code from said variable code generator such that said variable code constitutes at least part of said identification code, and modulation and amplification means for modulating a carrier with said identification code in order to create said identification signal. - View Dependent Claims (5, 6, 7)
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18. An object identification system comprising:
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a transceiver having a first signal detection sensitivity and including means for transmitting a write signal; and a transponder having a second signal detection sensitivity less than said first sensitivity, the transponder including means for receiving and detecting said write signal, a memory device for storing an identification code of said transponder, said identification code including bits able to have a plurality of logical states, and means for creating an identification signal representative of said identification code such that said identification signal is modulated by the logical state of said bits; said transceiver further comprising means for receiving and interpreting said identification signal; said transponder further comprising a variable code generator, and means for writing in said memory device, in response to the detection of said write signal, a variable code from said variable code generator such that said variable code constitutes at least part of said identification code; and wherein said variable code generator includes a cyclically incremented and non-determinatedly stopping output counter. - View Dependent Claims (19, 20, 21, 22)
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Specification