EP0789253A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Detection of multiple articles
Assignee: ZIH Corp
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Filing: 1993-11-18
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Granted: —
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Expires: 2013-11-18
Abstract
Abstract An identification system comprises an interrogator and a plurality of transponders. The interrogator includes a transmitter which transmits at least two independent interrogation signals to the transponders, and a receiver for receiving response signals from the transponders. The interrogator also includes processor means for identifying the transponders from data in the received response signals. Each transponder comprises receiving means, a code generator, and transmitter means connected to the code generator. On receipt of at least one of the transmitted interrogation signals the transponder transmits a response signal containing data which identifies it. The interrogation signals are transmitted continuously. In a preferred embodiment, the interrogation signals are relatively narrow bandwidth signals at different frequencies. The receiving means of each transponder has a relatively broad reception bandwidth so that the transponder is responsive to one or more of the interrogation signals.
Inventors
- 👤 Michael John Camille Marsh
- 👤 Andrzej Lenarcik
- 👤 Clinton Aiden Van Zyl
- 👤 Andries Christoffel Van Schalkwyk
- 👤 Marthinus Jacobus Rudolph Oosthuizen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 14:30
CPC Classifications
G; G06; G06F; G06F17/00; H; H01; H01Q; H01Q1/00; H01Q1/12; H01Q1/22; H01Q1/2208; H01Q1/2216; A; A47; A47F; A47F9/00; A47F9/02; A47F9/04; A47F9/046; A47F9/047; A47F9/048; G01; G01S; G01S13/00; G01S13/02; G01S13/06; G01S13/08; G01S13/10; G01S13/24; G01S13/74; G01S13/75; G01S13/751; G01S13/758; G06K; G06K17/00; G06K17/0022; G06K7/00; G06K7/0008; G06K7/10; G06K7/10009; G06K7/10019; G06K7/10029; G06K7/10059; G06K7/10316; G06K7/10336; G06K7/10346; G07; G07C; G07C9/00; G07C9/20; G07C9/28; G07G; G07G1/00; G07G1/0036; G07G1/0045; G07G1/0054; G07G3/00; G07G3/003; G07G3/006; G08; G08B; G08B13/00; G08B13/22; G08B13/24; G08B13/2402; G08B13/2405; G08B13/2422; G08B13/2451; G08B13/246; G08B13/2465; G08B13/2468; G08B13/2471; G08B13/2474; G08B13/2485; G08B13/2488; H01Q21/00; H01Q21/06; H01Q21/061; H01Q21/065; G01S13/87
Claims Analysis
Total Claims: 48
Claim 1
Independent Claim
137 words
An identification system comprising an interrogator and a plurality of transponders, the interrogator including transmitter means for transmitting an interrogation signal to the transponders, receiver means for receiving response signals from the transponders, and processor means for identifying the transponders from data in the response signals; each transponder comprising receiving means, a code generator, and transmitting means connected to the code generator, so that on receipt of the transmitted interrogation signal the transponder transmits a response signal containing data which identifies the transponder; characterised in that the interrogator transmitter transmits a plurality of simultanteous interrogation signals at a plurality of frequencies, each transponder transmits a response signal on receipt of at least one of the interrogation signals and the interrogator identifies response signals from the same transponder which are transmitted at some or all of the frequencies.
Claim 2
Dependent Claim
24 words
An identification system according to claim 1 wherein the transmitter means of the interrogator is adapted to transmit the plurality of interrogation signals continuously.
Claim 3
Dependent Claim
33 words
An identification system according to claims 1 or 2 wherein the interrogation signals have respective different frequencies which are selected to fall within the reception bandwidth of the receiving means of the transponders.
Claim 4
Dependent Claim
54 words
An identification system according to claim 3 wherein the interrogation signals are relatively narrow bandwidth signals, the receiving means of each transponder having a relatively broad reception bandwidth within which the respective different frequencies of the interrogation signals fall, so that the transponder is responsive to any one or more of the interrogation signals.
Claim 5
Dependent Claim
37 words
An identification system according to claim 4 wherein each interrogation signal is modulated with data, the data modulation bandwidth of each interrogation signal being less than the spacing between the respective different frequencies of the interrogation signals.
Claim 6
Dependent Claim
54 words
An identification system according to any one of claims 1 to 5 wherein the transmitting means of the transponder comprises an antenna and means for modulating the reflectivity of the antenna, so that the response signal of the transponder comprises one or more interrogation signal carriers modulated with the data which identifies the transponder.
Claim 7
Dependent Claim
41 words
An identification system according to any one of claims 1 to 6 wherein the transmitter means of the interrogator comprises at least two spaced apart transmitting antenna elements and the receiver means comprises at least two spaced apart receiving antenna elements.
Claim 8
Dependent Claim
42 words
An identification system according to any one of claims 1 to 6 wherein the transmitter means and the receiver means comprise at least two spaced apart antenna units, each antenna unit comprising a transmitting antenna element and an adjacent receiving antenna element.
Claim 9
Dependent Claim
29 words
An identification system according to claims 7 or 8 wherein each antenna element comprises a patch array designed to operate at a frequency between 800 MHz and 1 GHz.
Claim 10
Dependent Claim
30 words
An identification system according to any one of claims 7 to 9 wherein at least two of the respective transmitting and receiving antenna elements are polarized differently from one another.
Claim 11
Dependent Claim
45 words
An identification system according to claim 7 wherein the receiver means and the processor means of the interrogator are adapted to distinguish response signals from transponders in response to interrogation signals transmitted at the respective different frequencies of the at least first and second transmitters.
Claim 12
Dependent Claim
29 words
An identification system according to claim 11 wherein the processor means is adapted to detect duplicate transponder response signals transmitted on two or more of the respective different frequencies.
Claim 13
Dependent Claim
28 words
An identification system according to claim 11 wherein the processor means is adapted to disregard transponder response signals transmitted on two or more of the respective different frequencies.
Claim 14
Dependent Claim
46 words
An identification system according to any one of claims 1 to 13 wherein the transmitter means and the receiver means of the interrogator are mounted on or adjacent to a structure which defines an interrogation zone through which the transponders to be identified may be passed.
Claim 15
Dependent Claim
40 words
An identification system according to claim 14 wherein the transmitter means and the receiver means of the interrogation are supported by a frame defining a passage through which a conveyance containing articles to which respective transponders are attached can pass.
Claim 16
Dependent Claim
49 words
An identification system according to any one of claims 1 to 13 wherein the interrogation signals have respective different frequencies which are selected so that there are no overlapping nulls in the electric fields of the interrogation signals within a predetermined distance of the transmitter means of the interrogator.
Claim 17
Dependent Claim
37 words
An identification system according to any one of claims 1 to 16 including processor means for recording data received from each identified transponder and for relating the received data to stored data corresponding to the received data.
Claim 18
Dependent Claim
37 words
An identification system according to claim 17 wherein the processor means is adapted to store price or identification data of articles to which different transponders are attached, and to relate the identification codes of identified transponders thereto.
Claim 19
Dependent Claim
31 words
An identification system according to claim 18 including display means for generating a display in which descriptions of the articles to which respective transponders are attached are associated with price data.
Claim 20
Dependent Claim
17 words
An identification system according to claim 19 including printer means for generating a printout of the display.
Claim 21
Dependent Claim
84 words
An interrogator for identifying a plurality of transponders comprising the interrogator including transmitter means for transmitting an interrogation signal to the transponders, receiver means for receiving response signals from the transponders, and processor means for identifying transponders from data in the response signals; characterised in that the interrogator transmitter transmits a plurality of simultanteous interrogation signals at a plurality of frequencies and the interrogator is adapted to identify response signals from the same transponder which are transmitted at some or all of the frequencies.
Claim 22
Dependent Claim
23 words
An interrogator according to claim 21 wherein the transmitter means of the interrogator is adapted to transmit the plurality of interrogation signals continuously.
Claim 23
Dependent Claim
16 words
An interrogator according to claims 21 or 22 wherein the interrogation signals have respective different frequencies.
Claim 24
Dependent Claim
15 words
An interrogator according to claim 23 wherein the interrogation signals are relatively narrow bandwidth signals.
Claim 25
Dependent Claim
36 words
An interrogator according to claim 24 wherein each interrogation signal is modulated with data, the data modulation bandwidth of each interrogation signal being less than the spacing between the respective different frequencies of the interrogation signals.
Claim 26
Dependent Claim
40 words
An interrogator according to any one of claims 21 to 25 wherein the transmitter means of the interrogator comprises at least two spaced apart transmitting antenna elements and the receiver means comprises at least two spaced apart receiving antenna elements.
Claim 27
Dependent Claim
41 words
An interrogator according to any one of claims 21 to 25 wherein the transmitter means and the receiver means comprise at least two spaced apart antenna units, each antenna unit comprising a transmitting antenna element and an adjacent receiving antenna element.
Claim 28
Dependent Claim
28 words
An interrogator according to claims 26 or 27 wherein each antenna element comprises a patch array designed to operate at a frequency between 800 MHz and 1 GHz.
Claim 29
Dependent Claim
29 words
An interrogator according to any one of claims 26 to 28 wherein at least two of the respective transmitting and receiving antenna elements are polarized differently from one another.
Claim 30
Dependent Claim
39 words
An interrogator according to claim 26 wherein the receiver means and the processor means of the interrogator are adapted to distinguish response signals from transponders transmitted at the respective different frequencies of the at least first and second transmitters.
Claim 31
Dependent Claim
28 words
An interrogator according to claim 21 wherein the processor means is adapted to detect duplicate transponder response signals transmitted on two or more of the respective different frequencies.
Claim 32
Dependent Claim
27 words
An interrogator according to claim 21 wherein the processor means is adapted to disregard transponder response signals transmitted on two or more of the respective different frequencies.
Claim 33
Dependent Claim
35 words
An interrogator according to any one of claims 21 to 32 wherein the transmitter means and the receiver means of the interrogator are mounted on or adjacent to a structure which defines an interrogation zone.
Claim 34
Dependent Claim
33 words
An interrogator according to claim 33 wherein the transmitter means and the receiver means of the interrogation are supported by a frame defining a passage through which a conveyance containing articles can pass.
Claim 35
Dependent Claim
48 words
An interrogator according to any one of claims 21 to 34 wherein the interrogation signals have respective different frequencies which are selected so that there are no overlapping nulls in the electric fields of the interrogation signals within a predetermined distance of the transmitter means of the interrogator.
Claim 36
Independent Claim
106 words
A method of identifying a plurality of transponders comprising the steps of transmitting an interrogation signal to the transponders, each transponder receiving the interrogation and transmitting a signal, containing data, in response, receiving the response signals from the transponders, identifying transponders from data in the response signals, detecting successful identification of any transponder, characterised in that a plurality of simultanteous interrogation signals at a plurality of frequencies are transmitted, a response signal is transmitted by each transmitter on receipt of at least one of the interrogation signals and response signals from the same transponder which are transmitted at some or all of the frequencies are identified.
Claim 37
Dependent Claim
15 words
A method according to claim 36 wherein a plurality of interrogation signals are transmitted continuously.
Claim 38
Independent Claim
27 words
A method according to claims 37 or 38 wherein respective different frequencies of the interrogation signals are selected to fall within the reception bandwidth of the transponders.
Claim 39
Dependent Claim
34 words
A method according to claim 38 wherein the interrogation signals have relatively narrow bandwidth and the transponders have a relatively broad reception bandwidth within which the respective different frequencies of the interrogation signals fall.
Claim 40
Dependent Claim
36 words
A method according to claim 39 wherein each interrogation signal is modulated with data, the data modulation bandwidth of each interrogation signal being less than the spacing between the respective different frequencies of the interrogation signals.
Claim 41
Independent Claim
33 words
A method according to any one of claims 36 to 40 wherein the response signal of a transponder comprises one or more interrogation signal carriers modulated with the data which identifies said transponder.
Claim 42
Dependent Claim
23 words
A method according to claim 36 wherein duplicate transponder response signals transmitted on two or more of the respective different frequencies are detected.
Claim 43
Dependent Claim
22 words
A method according to claim 36 wherein transponder response signals transmitted on two or more of the respective different frequencies are disregarded.
Claim 44
Independent Claim
48 words
A method according to any one of claims 36 to 43 wherein the interrogation signals have respective different frequencies which are selected so that there are no overlapping nulls in the electric fields of the interrogation signals within a predetermined distance of the transmitter means of the interrogator.
Claim 45
Independent Claim
32 words
A method according to any one of claims 36 to 44 including recording data received from each identified transponder and relating the received data to stored data corresponding to the received data.
Claim 46
Dependent Claim
32 words
A method according to claim 45 wherein the price or identification data of articles to which different transponders are attached are stored, and the identification codes of identified transponders are related thereto.
Claim 47
Dependent Claim
25 words
A method according to claim 46 including displaying descriptions of the articles to which respective transponders are attached and associating said articles with price data.
Claim 48
Dependent Claim
13 words
A method according to claim 47 including printing a printout of the display.
References Cited (Backward Citations)
No citation records indexed.
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