High speed system for reading and writing data from and into remote tags
First Claim
1. A system for reading data from and for writing data into a tag associated with an object which is moveable relative to an interrogator, comprising:
- an interrogator means for sending a modulated RF signal to said tag, said signal including data intended to be received and stored by said tag;
at least one tag means which, upon receipt of a continuous RF signal, backscatter-modulates said RF signal and returns a backscatter-modulated signal to said interrogator, said backscatter-modulated signal being modulated with data relating to said remote object and being made up of signals of first and second frequencies F1 and 2f1, respectively, where the second frequency 2f1 is twice the first frequency f1, and where one of the two binary bits ONE and ZERO is represented by one-half period of a signal of said first frequency followed by one period of said second frequency, and the other of said two binary bits is represented by one period of a signal of said second frequency followed by one-half period of a signal of said first frequency;
said interrogator means (1) obtaining information from said tag means from said returned backscatter-modulated signal made up of the said signals of first and second frequencies and (2) transmitting data to said tag means, whereby data may be READ from, transmitted to and stored by said tag means very rapidly while said tag means or said interrogator means is moving.
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Accused Products
Abstract
A system for reading from and for writing data into electronic tags which may be associated with objects which are moving with respect to an interrogator, or may be located in fixed positions in the path of a moving interrogator. The interrogator, which is stationary if the tag is moving, sends a continuous RF signal to the remote tag. The tag backscatter-modulates the received RF signal with data temporarily or permanently stored in the tag, including, for example, data associated with the object to which the tag is attached, for example, its identity or contents. The system of this invention uses a very efficient encoding technique for the data which is backscatter-modulated by the tag and received by the interrogator. The backscatter-modulated signals are made up of signals of first and second frequencies f1 and 2f1, respectively, where the second frequency 2f1 is twice the first frequency f1, and where one of the two binary bits ONE and ZERO is represented by one-half period of a signal of the first frequency followed by one period of the second frequency, and the other of the two binary bits is represented by one period of a signal of the second frequency followed by one-half period of a signal of the first frequency. The signals also contain FRAME MARKERS made up of five periods of frequency 2f1 followed by one-half period of frequency f1.
239 Citations
25 Claims
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1. A system for reading data from and for writing data into a tag associated with an object which is moveable relative to an interrogator, comprising:
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an interrogator means for sending a modulated RF signal to said tag, said signal including data intended to be received and stored by said tag; at least one tag means which, upon receipt of a continuous RF signal, backscatter-modulates said RF signal and returns a backscatter-modulated signal to said interrogator, said backscatter-modulated signal being modulated with data relating to said remote object and being made up of signals of first and second frequencies F1 and 2f1, respectively, where the second frequency 2f1 is twice the first frequency f1, and where one of the two binary bits ONE and ZERO is represented by one-half period of a signal of said first frequency followed by one period of said second frequency, and the other of said two binary bits is represented by one period of a signal of said second frequency followed by one-half period of a signal of said first frequency; said interrogator means (1) obtaining information from said tag means from said returned backscatter-modulated signal made up of the said signals of first and second frequencies and (2) transmitting data to said tag means, whereby data may be READ from, transmitted to and stored by said tag means very rapidly while said tag means or said interrogator means is moving. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A tag adapted to be attached to a remote object, said tag containing data associated with said remote object and having at least a portion of its data contents variable by the receipt of a modulated RF signal from an interrogator which is moveable relative to said tag, comprising:
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a writable, non-volatile memory; a backscatter-modulating means which, upon receipt of a continuous RF signal, backscatter-modulates said RF signal and returns a backscatter-modulated signal to said interrogator, said backscatter-modulated returned signal being modulated with said data associated with said remote object, said backscatter-modulated signal being made up of signals of first and second frequencies f1 and 2f1, respectively, where the second frequency 2f1 is twice the first frequency f1, and where one of the two binary bits ONE and ZERO is represented by one-half period of a signal of said first frequency followed by one period of said second frequency, and the other of said two binary bits is represented by one period of a signal of said second frequency followed by one-half period of a signal of said first frequency. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A system for reading data from and for writing data into a tag associated with a remote object, said tag being moveable relative to the interrogator, comprising:
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an interrogator means for sending a modulated RF WRITE signal to said tag, said WRITE signal including data to be received and stored by said tag, said modulated RF WRITE signal having a first binary digit represented by a signal having a frequency 2f2 and the other binary digit represented by a signal having a frequency 4f2 ; at least one tag means which, upon receipt of a continuous RF signal, backscatter-modulates said continuous RF signal and returns a backscatter-modulated signal to said interrogator made up of two different frequencies, said backscatter-modulated signal being modulated with data relating to said remote object; said interrogator means (1) obtaining information from said tag means from said returned backscatter-modulated signal made up of the said signals of first and second frequencies and (2) transmitting data to said tag means, whereby data may be READ from, transmitted to and stored by said tag means very rapidly while said tag means or said interrogator means is moving. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
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Specification