RFID conveyor system and method

• US 20060244608A1
• Filed: 03/23/2006
• Published: 11/02/2006
• 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 7,586,411 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, 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, at least one first antenna, at least one second antenna, a radio frequency receiver, and a processor. The processor associates a first signal with a first item if the processor receives the first signal from the receiver while at least a portion of the first item is within a first area that includes at least part of a second area into which the antenna radiates radio frequency signals. The first antenna radiates radio frequency signals if at least one item is in the path of travel within a third area that includes, and is larger than, the first 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;

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

at least one second antenna disposed proximate the path of travel so that the second antenna receives responses to the radio frequency signals from the respective radio frequency identification tags on the items;

a radio frequency receiver that receives signals from the second antenna corresponding to the responses received by the second 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,

wherein

the processor associates 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 a second area that includes at least part of the first area, and

the at least one first antenna radiates the radio frequency signals if at least one said item is in the path of travel within a third area with respect to the path of travel that includes, and is larger than, the second area.

2. The system as in claim 1, wherein each said at least one first antenna and a corresponding said second antenna comprise a single antenna.

3. The system as in claim 1, wherein the third area extends upstream, with respect to the path of travel, from the second area.

4. The system as in claim 2, wherein if the processor associates with the first item any said first signal received by the processor while at least a portion of the first item is within the second area, the processor does not associate any other said first signal with the first item where the processor receives the other first signal while the first item is entirely outside the second area.

5. The system as in claim 1, wherein the processor defines a length of the second area with respect to the path of travel based on a distance between the first item and a second said item next following the first item upstream in the path of travel.

6. The system as in claim 5, wherein the processor compares the distance to a default length of the second area, and if the distance is less than the default length, decreases the length of the second area to a value that excludes simultaneous presence of the first item and the second item in the second area.

7. The system as in claim 1, including a plurality of said first antennas and a plurality of said second antennas.

8. The system as in claim 7, wherein the plurality of first antennas and second antennas are disposed with respect to the path of travel so that a plurality of respective said second areas corresponding to the antennas coincide with each other.

9. 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;

at least one first antenna disposed proximate the path of travel so that the first antenna radiates radio frequency signals into a first area that is proximate the belt and through which the items pass;

at least one second antenna disposed proximate the path of travel so that the second antenna receives responses to the radio frequency signals from the respective radio frequency identification tags on the items on the belt;

a radio frequency receiver that receives signals from the second antenna corresponding to the responses received by the second 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,

wherein

the processor associates 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 a second area that includes at least part of the first area, and

the at least one first antenna radiates the radio frequency signals if at least one said item is on the belt within a third area with respect to the path of travel that includes, and is larger than, the second area.

10. The system as in claim 9, wherein the third area extends upstream, with respect to the path of travel, from the second area.

11. The system as in claim 9, wherein a single antenna comprises each said first antenna and a respective said second antenna.

12. The system as in claim 11, wherein if the processor associates with the first item any said first signal received by the processor while at least a portion of the first item is within the second area, the processor does not associate any other said first signal with the first item where the processor receives the other first signal while the first item is entirely outside the second area.

13. The system as in claim 11, wherein the processor associates the 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 a predetermined fourth area adjacent the second area and if the processor does not associate any said first signal with the first item while at least a portion of the first item is within the second area.

14. The system as in claim 13, wherein the fourth area is immediately upstream from the second area, with respect to the path of travel.

15. The system as in claim 11, wherein the processor defines a length of the second area with respect to the path of travel based on a distance between the first item and a second said item next following the first item on the belt with respect to the path of travel.

16. The system as in claim 15, wherein the processor compares the distance to a default length of the second area, and if the distance is less than the default length, decreases the length of the second area to a value that excludes simultaneous presence of the first item and the second item in the second area.

17. The system as in claim 11, including a plurality of said single antennas.

18. The system as in claim 17, 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 antennas coincide with each other.

19. 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;

at least one antenna disposed proximate the belt so that the antenna

radiates radio frequency signals into a first area that is proximate the belt and through which the items pass and

receives 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 radio frequency identification tag from which said response is received;

a radio frequency transmitter that drives the antenna to emit the radio frequency signals into the first area;

a radio frequency receiver that receives signals from the antenna corresponding to the responses received by the antenna from the 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 controls the transmitter to drive the antenna and that receives the first signals from the receiver and the second signals from the detector,

wherein the processor is programmed to

responsive to the second signals, track each said item with respect to a second position that is downstream from the first position with respect to the path of travel, when said item is on the belt between the first position and the second position, and

associate said information included in a said first signal with a first said item if the processor receives said first signal from the receiver during a period in which at least a portion of the first item passes the second position and travels through a predetermined first distance downstream from the second position.

20. The system as in claim 19, wherein the processor defines the first distance with respect to the path of travel based on a second distance between the first item and a second item next following the first item on the belt with respect to the path of travel.

21. The system as in claim 20, wherein the processor compares the second distance to a default length of the first distance, and if the second distance is less than the default length, decreases the first distance to a value that excludes simultaneous presence of the first item and the second item in an area of the path of travel defined by the first distance downstream from the second position.

22. The system as in claim 19, wherein, based on the second signals, the processor determines a second distance between the first item and a second item next following the first item on the belt with respect to the path of travel and defines the first distance with respect to the path of travel based on the second distance.

23. The system as in claim 21, wherein the processor compares the second distance to a default length of the first distance, and if the second distance is less than the default length, decreases the first distance to a value that excludes simultaneous presence of the first item and the second item in an area of the path of travel defined by the first distance 5 downstream from the second position.

24. The system as in claim 19, including a plurality of said antennas.

25. The system as in claim 24, wherein the plurality of antennas are disposed with respect to the path of travel so that a plurality of respective said second positions corresponding to the antennas coincide with each other.

26. The system as in claim 19, including a tachometer that operatively engages the belt and outputs third signals corresponding to movement of the belt through the path of travel, wherein the processor tracks each said item with respect to the second position based on the third signals.

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

providing at least one first antenna disposed proximate the path of travel so that the first antenna radiates radio frequency signals into a first area that is proximate the path of travel and through which the items pass; and

providing at least one second antenna disposed proximate the path of travel so that the second antenna receives responses to the radio frequency signals from the respective radio frequency identification tags on the items;

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

associating a said first signal with a first said item if the receiver outputs said first signal while at least a portion of the first item is within a second area that includes at least part of the first area; and

driving the at least one first antenna to radiate the radio frequency signals if at least one said item is within the path of travel within a third area with respect to the frame that includes, and is larger than, the second area.

28. The method as in claim 28, wherein each said at least one first antenna and a corresponding said second antenna comprise a single antenna.