RFID conveyor system and method

• US 20060232420A1
• Filed: 03/23/2006
• Published: 10/19/2006
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Datalogic Automation Incorporated (Datalogic S.p.A.)
• Original Assignee: Accu-Sort Systems Incorporated (Datalogic S.p.A.)
• Inventors: Cox, James N.
• Granted Patent: US 7,548,162 B2
• Time in Patent Office: Days
• US Class Current: 340/572.700
• CPC Class Codes: B07C 5/3412 according to a code applied to the object which indicates a property of the object, e.g. quality class, contents or incorrect indication sorting according to size measured by light-responsive means B07C5/10; sorting according to optical properties B07C5/342; for packages B65D79/02; for information carriers G06K7/00
• CPC Class Codes: B65G 2203/042 Sensors
• CPC Class Codes: G06K 17/00 Methods or arrangements for effecting co-operative working between equipments covered by two or more of main groups G06K1/00 - G06K15/00, e.g. automatic card files incorporating conveying and reading operations
• CPC Class Codes: G06K 2207/1012 Special detection of object
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10079 the collision being resolved in the spatial domain, e.g. temporary shields for blindfolding the interrogator in specific directions
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil
• CPC Class Codes: G06K 7/10346 the antenna being of the far field type, e.g. HF types or dipoles
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: G06K 7/10435 the interrogation device being positioned close to a conveyor belt or the like on which moving record carriers are passing conveying in accordance with bodily destination marks, see B65G47/46, sorting of objects carrying identity markings, see B07C5/34
• CPC Class Codes: G06Q 10/08 Logistics, e.g. warehousing, loading or distribution; Inventory or stock management
• CPC Class Codes: H01Q 1/2208 associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems methods or arrangements for sensing record carriers, e.g. for reading patterns G06K7/00; record carrier for use with machines and with at least a part designed to carry digital markings G06K19/00
• CPC Class Codes: H01Q 1/2216 used in interrogator/reader equipment
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres
• CPC Class Codes: H01Q 17/001 for modifying the directional characteristic of an aerial
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40
• CPC Class Codes: H01Q 9/0428 : radiating a circular polarised wave

Abstract

A conveyor system for processing items on which radio frequency identification tags are disposed includes a frame and a conveyor disposed moveably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon. A plurality of antennas are disposed proximate the path of travel so that the plurality of antennas radiate radio frequency signals into first areas through which the items pass and receive responses to the radio frequency signals from the respective radio frequency identification tags on the items. A first antenna is offset with respect to the path of travel from a second antenna so that the radio frequency signals from the second antenna generally do not interfere with reception of responses by the first antenna from radio frequency identification tags located within a predetermined second area along the path of travel. A radio frequency receiver receives signals from the first antenna corresponding to the responses received by the first antenna from the radio frequency identification tags and outputs first signals corresponding to the responses. A processor receives the first signals from the receiver and is programmed to associate a first signal with the first item if the processor receives the first signal from the receiver while at least a portion of the first item is within the second area.

Claims

1. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a conveyor disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

a plurality of antennas disposed proximate the path of travel so that the plurality antennas

radiates radio frequency signals into first areas through which the items pass and

receives responses to the radio frequency signals from the respective radio frequency identification tags on the items in the path of travel,

wherein a first said antenna is offset with respect to the path of travel from a second said antenna so that the radio frequency signals from the second antenna generally do not interfere with reception of responses by the first antenna from radio frequency identification tags located within a predetermined second area along the path of travel;

a radio frequency receiver that receives signals from the first antenna corresponding to the responses received by the first antenna from the radio frequency identification tags and outputs first signals corresponding to the responses; and

a processor that receives the first signals from the receiver and is programmed to associate a said first signal with a first said item if the processor receives the first signal from the receiver while at least a portion of the first item is within the second area.

2. The system as in claim 1, wherein the first antenna is offset upstream from the second antenna with respect to the path of travel.

3. The system as in claim 2, wherein the first antenna is offset upstream from the second antenna by a first distance with respect to the path of travel, and wherein the processor is programmed to

store the first signals received from the receiver for a time required for the first item from which the responses corresponding to the stored first signals were received to travel the first distance along the path of travel and

then associate the stored first signals with the first item if the processor received the stored second signals from the at least one receiver while at least a portion of the first item was within the second area.

4. The system as in claim 1, including a plurality of said second antennas.

5. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a conveyor that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

a first antenna disposed proximate the path of travel so that the first antenna radiates first radio frequency signals into a first area through which the items pass;

a second antenna disposed proximate the path of travel so that the second antenna receives first responses to the first radio frequency signals from the respective radio frequency identification tags on the items in the path of travel;

a third antenna disposed proximate the path of travel so that the third antenna receives second responses to second radio frequency signals from the respective radio frequency identification tags on the items in the path of travel;

at least one radio frequency receiver that

receives signals from the second antenna corresponding to the first responses received by the second antenna from the respective radio frequency identification tags and outputs first signals corresponding to the first responses, and

receives signals from the third antenna corresponding to the second responses received by the third antenna from the respective radio frequency identification tags and outputs second signals corresponding to the second responses; and

a processor that receives the first signals and the second signals from the at least one receiver and is programmed to

associate a said first signal with a first said item if the processor receives the first signal from the at least one receiver while at least a portion of the first item is within a predetermined second area in the path of travel, and

associate a said second signal with the first item if the processor receives the second signal from the at least one receiver while at least a portion of the first item is within a predetermined third area in the path of travel,

wherein the third antenna is disposed upstream, with respect to the path of travel, from the first antenna and from the second antenna so that the third area is offset upstream from the second area and the radio frequency signals from the first antenna generally do not interfere with reception of the second responses by the third antenna.

6. The system as in claim 5, wherein the third antenna is offset upstream from the second antenna by a first distance with respect to the path of travel, and wherein the processor is programmed to

store the second signals received from the at least one receiver for a time required for the first item from which the responses corresponding to the stored second signals were received to travel the first distance along the path of travel and

then associate the stored second signals with the first item if the processor received the stored second signals from the at least one receiver while at least a portion of the first item was within the third area.

7. The system as in claim 5, wherein a single antenna comprises a said first antenna and a said second antenna.

8. The system as in claim 7, including a plurality of said single antennas.

9. The system as in claim 8, wherein the plurality of single antennas are disposed with respect to the path of travel so that a plurality of respective said second areas corresponding to the single antennas coincide with each other.

10. The system as in claim 9, including a radio frequency transmitter that drives the single antennas to emit the first radio frequency signals into the first area in sequence with respect to each other.

11. The system as in claim 9, wherein the conveyor travels above a top surface of the frame and wherein the third antenna is disposed on the frame below the conveyor.

12. The system as in claim 11, wherein the third antenna is offset upstream from the single antennas by a first distance with respect to the path of travel, and wherein the processor is programmed to

store the second signals received from the at least one receiver for a time required for the first item from which the responses corresponding to the stored second signals were received to travel the first distance along the path of travel and

then associate the stored second signals with the first item if the processor received the stored second signals from the at least one receiver while at least a portion of the first item was within the third area.

13. The system as in claim 5, including a plurality of said third antennas, wherein each said third antenna radiates radio frequency signals into a respective first area and is disposed upstream, with respect to the path of travel, from the first antenna and from the second antenna by a respective first distance so that

the third area corresponding to each said third antenna is offset upstream from the second area,

the radio frequency signals from the first antenna generally do not interfere with reception of the second responses by the third antennas, and

the radio frequency signals from any said third antenna generally does not interfere with reception of the second responses by any other said third antenna.

14. The system as in claim 13, wherein each third antenna is offset upstream from the second antenna by a respective first distance with respect to the path of travel, and wherein the processor is programmed to

store the second signals received from the at least one receiver corresponding to each said third antenna for a time required for the first item from which the responses corresponding to the stored second signals were received to travel the respective first distance along the path of travel and

then associate the stored second signals with the first item if the processor received the stored second signals from the at least one receiver while at least a portion of the first item was within the third area corresponding to the third antenna.

15. The system as in claim 5, including

a first group of antennas having a said first antenna, a said second antenna and a said third antenna, and

a second group of antennas having a said first antenna, said second antenna and said third antenna,

wherein the first group of antennas is disposed upstream from the second group of antennas so that radio frequency signals radiated by either the first group or the second group generally do not interfere with reception of responses by antennas within the other of the first group and the second group, and

wherein the radio frequency signals radiated by the first group include query signals for a first class protocol and not a second class protocol, and the radio frequency signals radiated by the second group include query signals for the second class protocol and not the first class protocol.

16. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a generally planar belt that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

a plurality of antennas disposed proximate the belt so that the antennas

radiate radio frequency signals into respective predetermined first areas that are proximate the belt and through which the items pass and

receive responses to the radio frequency signals from the respective radio frequency identification tags on the items on the belt;

at least one radio frequency receiver that receives signals from the antennas corresponding to the responses received by the antennas from the respective radio frequency identification tags and outputs first signals corresponding to the responses; and

a processor that receives the first signals from the at least one receiver and is programmed to associate a said first signal with a first said item if the processor receives the first signal from the at least one receiver while at least a portion of the first item is within the respective predetermined first area corresponding to any of the plurality of antennas,

wherein

a first said antenna is offset downstream with respect to the path of travel from a second said antenna so that

the radio frequency signals from the first antenna generally do not interfere with reception of and response to the radio frequency signals from the second antenna by a said radio frequency identification tag in the respective first area of the second antenna, and

the radio frequency signals from the second antenna generally do not interfere with reception of and response to the radio frequency signals from the first antenna by a said radio frequency identification tag in the respective first area of the first antenna.

17. The system as in claim 16, wherein the second antenna is offset upstream from the first antenna by a first distance with respect to the path of travel, and wherein the processor is programmed to

store the first signals received from the at least one receiver and corresponding to responses received by the second antenna for a time required for the first item from which the responses corresponding to the stored first signals were received to travel the first distance along the path of travel and

then associate the stored first signals with the first item if the processor received the stored first signals from the at least one receiver while at least a portion of the first item was within the respective first area of the second antenna.

18. The system as in claim 16, including a plurality of said first antennas disposed with respect to the path of travel so that a plurality of respective first areas of the plurality of first antennas coincide with each other.

19. The system as in claim 18, wherein the belt travels above a top surface of the frame and wherein the second antenna is disposed on the frame below the belt.

20. The system as in claim 19, wherein the second antenna is offset upstream from the first antennas by a first distance with respect to the path of travel, and wherein the processor is programmed to

store the first signals received from the at least one receiver and corresponding to responses received by the second antenna for a time required for the first item to travel the first distance along the path of travel and

then associate the stored first signals with the first item if the processor received the stored first signals from the at least one receiver while at least a portion of the first item was within the respective first area of the second antenna.

21. The system as in claim 16, including a plurality of said second antennas, wherein each said second antenna radiates radio frequency signals into its said respective first area and is disposed upstream, with respect to the path of travel, from the first antenna by a respective first distance so that

the respective first area of each said second antenna is offset upstream from the respective first area of each other said second antenna and from the respective first area of the first antenna,

the radio frequency signals from the first antenna generally do not interfere with reception of the responses by the second antennas, and

the radio frequency signals from any said second antenna generally does not interfere with reception of the responses by any other said second antenna.

22. The system as in claim 21, wherein each second antenna is offset upstream from the first antenna by a respective first distance with respect to the path of travel, and wherein the processor is programmed to

store the first signals received from the at least one receiver and corresponding to responses received by each second antenna for a time required for the first item to travel the respective first distance along the path of travel and

then associate the stored first signals with the first item if the processor received the stored first signals from the at least one receiver while at least a portion of the first item was within the respective first area of the second antenna.

23. The system as in claim 16, including

a first group of antennas having a said first antenna and a said second antenna, and

a second group of antennas having a said first antenna and a said second antenna,

wherein the first group of antennas is disposed upstream from the second group of antennas so that radio frequency signals radiated by either the first group or the second group generally do not interfere with reception of responses by antennas within the other of the first group and the second group, and

wherein the radio frequency signals radiated by the first group include query signals for a first class protocol and not a second class protocol, and the radio frequency signals radiated by the second group include query signals for the second class protocol and not the first class protocol.

24. A conveyor system for processing items on which radio frequency identification tags are disposed, said system comprising:

a frame;

a generally planar belt that is disposed movably on the frame and that conveys items through a path of travel, each item having at least one respective radio frequency identification tag disposed thereon;

a plurality of antennas disposed proximate the belt so that the antennas

radiate radio frequency signals into respective predetermined first areas that are proximate the belt and through which the items pass and

receive responses to the radio frequency signals from the respective radio frequency identification tags on the items on the belt, wherein each response includes information that identifies the respective radio frequency identification tag from which said response is received;

at least one radio frequency transmitter that drives the antennas to emit the radio frequency signals into the respective first areas;

at least one radio frequency receiver that receives signals from the antennas corresponding to the responses received by the antennas from the respective radio frequency identification tags and outputs first signals corresponding to the responses and including the information;

a detector disposed with respect to the belt so that second signals output by the detector indicate presence of the items on the belt at a first position in the path of travel; and

a processor that

receives the first signals from the at least one receiver,

receives the second signals from the detector, and

responsive to the second signals, tracks each said item with respect to the first position and the respective predetermined first areas,

wherein

a first said antenna is disposed downstream with respect to the path of travel a first distance from a second said antenna so that

the radio frequency signals from the first antenna generally do not interfere with reception of and response to the radio frequency signals from the second antenna by a said respective radio frequency identification tag in the respective first area of the second antenna, and

the radio frequency signals from the second antenna generally do not interfere with reception of and response to the radio frequency signals from the first antenna by a said respective radio frequency identification tag in the respective first area of the first antenna, and

the processor is programmed to

associate said information included in a said first signal with a first said item after reception of the first signal from the at least one receiver while at least a portion of the first item is within the respective predetermined first area corresponding to the first antenna,

associate said information included in a said first signal with the first item after reception of the last mentioned first signal from the at least one receiver while at least a portion of the first item is within the respective predetermined first area corresponding to the second antenna and expiration of a time period required for the first item to travel the first distance along the path of travel, so that the last mentioned information is associated with the first item as if the respective first area for the second antenna coincided with the respective first area for the first antenna.

25. The system as in claim 24, including a plurality of said first antennas disposed with respect to the path of travel so that a plurality of respective first areas of the plurality of first antennas coincide with each other.

26. The system as in claim 25, wherein the belt travels above a top surface of the frame and wherein the second antenna is disposed on the frame below the belt.

27. The system as in claim 24, including a plurality of said second antennas, wherein each said second antenna radiates radio frequency signals into its said respective first area and is disposed upstream, with respect to the path of travel, from the first antenna by a respective first distance so that

the respective first area of each said second antenna is offset upstream from the respective first area of each other said second antenna and from the respective first area of the first antenna,

the radio frequency signals from the first antenna generally do not interfere with reception of the responses by the second antennas, and

the radio frequency signals from any said second antenna generally does not interfere with reception of the responses by any other said second antenna.

28. The system as in claim 24, including

a first group of antennas having a said first antenna and a said second antenna, and

a second group of antennas having a said first antenna and a said second antenna,

wherein the first group of antennas is disposed upstream from the second group of antennas so that radio frequency signals radiated by either the first group or the second group generally do not interfere with reception of responses by antennas within the other of the first group and the second group, and

wherein the radio frequency signals radiated by the first group include query signals for a first class protocol and not a second class protocol, and the radio frequency signals radiated by the second group include query signals for the second class protocol and not the first class protocol.

29. A method of processing items on each of which at least one respective radio frequency identification tag is disposed, where the items are conveyed through a path of travel by a generally planar belt that is disposed movably on a frame, said method comprising the steps of:

driving a plurality of antennas disposed proximate the belt so that the antennas

radiate radio frequency signals into respective predetermined first areas that are proximate the belt and through which the items pass and

receive responses to the radio frequency signals from radio frequency identification tags on the items on the belt,

wherein

a first said antenna is disposed at a first position that is offset upstream with respect to the path of travel a first distance from a second position at which a second said antenna is disposed so that

the radio frequency signals from the first antenna generally do not interfere with reception of and response to the radio frequency signals from the second antenna by a radio frequency identification tag in the respective first area of the second antenna, and

the radio frequency signals from the second antenna generally do not interfere with reception of and response to the radio frequency signals from the first antenna by a radio frequency identification tag in the respective first area of the first antenna;

providing at least one radio frequency receiver that receives signals from the antennas corresponding to the responses received by the antennas from the radio frequency identification tags and outputs first signals corresponding to the responses;

detecting presence of the items on the belt at a third position in the path of travel;

tracking each said item with respect to the third position and the respective predetermined first areas;

associating a said first signal with a first said item after reception of the first signal from the at least one receiver while at least a portion of the first item is within the respective predetermined first area corresponding to the second antenna; and

associating a said first signal with the first item after reception of the last mentioned first signal from the at least one receiver while at least a portion of the first item is within the respective first area corresponding to the first antenna and expiration of a time period required for the first item to travel the first distance along the path of travel, so that the stored last mentioned first signal is associated with the first item as if the respective first area for the first antenna coincided with the respective first area for the second antenna.