Programmable object identification transponder system
First Claim
1. A transponder comprising:
- a means for demodulating a received signal to produce a data signal in which each data character is encoded as a pair of different signal levels;
an instruction decoder for detecting an operation instruction in the data signal;
a means for storing indicium of each signal level of the data signal, and having one mode of operation in which the indicia of each signal level is written into said means for storing in response to a signal from said instruction decoder, and having another mode of operation in which previously stored indicia are read from said means for storing;
a modulator for modulating a carrier signal in response to he indicia read from said means for storing; and
means for powering the transponder with energy from the received signal.
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Accused Products
Abstract
A system for indenitfying objects, such as workpieces on an assembly line, includes a transponder for attaching to an object and a radio frequency (RF) transceiver. The transceiver can program the transponder with data about the specific object and interrogate the transponder to obtain previously programmed data. The transponder responds to different RF signal strengths and commands from the transceiver to select whether it will store or transmit data. Data is exchanged between the two devices using Manchester encoding. The transceiver processes the encoded data signal from the transponder by measuring and storing the intervals between level transitions in the signal. The stored intervals are then processed in non-real time to recover the data.
223 Citations
17 Claims
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1. A transponder comprising:
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a means for demodulating a received signal to produce a data signal in which each data character is encoded as a pair of different signal levels; an instruction decoder for detecting an operation instruction in the data signal; a means for storing indicium of each signal level of the data signal, and having one mode of operation in which the indicia of each signal level is written into said means for storing in response to a signal from said instruction decoder, and having another mode of operation in which previously stored indicia are read from said means for storing; a modulator for modulating a carrier signal in response to he indicia read from said means for storing; and means for powering the transponder with energy from the received signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An object identification transponder comprising:
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a means for demodulating a signal received by the transponder to recover data transmitted on the signal; a means for detecting the strength of the received signal; a memory for storing the recovered data; a memory for storing the recovere a modulator for modulating a carrier signal with data from said memory; and a means for controlling the operation of the transponder in response to the means for detecting the strength of the received signal, said controlling means placing the transponder in a first mode wherein the recovered data is stored in said memory when the strength of the received signal is greater than a first magnitude and placing the transponder in a second mode wherein the modulator modulates the carrier signal when the strength of the received signal greater than a second magnitude. - View Dependent Claims (10)
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11. A transceiver for an object identification system in which a transponder transmits a data signal in which data characters are each encoded as a pair of different signal levels, said transceiver comprising:
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means for receiving the transponder data signal; means for measuring the time interval between transitions in the level of the data signal from the transponder; means for comparing two consecutive time intervals to recover a transmitted data character. - View Dependent Claims (12, 13)
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14. An object identification system having a transponder, and a transceiver for interrogating the transponder and receiving data therefrom wherein,
said transponder comprises: -
means for receiving a signal from a transceiver in which the data characters are each encoded as a pair of different signal levels each occurring for a substantially equal predefined length of time; means for defining a series of intervals of time with each interval having a duration substantially equal to the predefined length of time; means for storing an indicium of the level of the received signal at each defined interval of time; means responsive to the signal from said transceiver for reading stored indicia from said means for storing, and transmitting a data signal having a level which depends on said stored indicia; and said transceiver comprises; means for receiving the data signal from said transponder; means for decoding the data signal to recover data characters represented by pairs of signal levels; means for interfacing said transceiver to an external data processing device; and means for transmitting a signal to said transponder. - View Dependent Claims (15, 16, 17)
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Specification