RFID conveyor system

• US 20060244609A1
• 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: Liu, Zhong-Min
• Granted Patent: US 7,518,513 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 that is 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. An antenna is disposed on the frame with respect to the path of travel so that the antenna radiates radio frequency signals into a first area through which the items pass. The antenna comprises a substrate and a plurality of patch elements disposed on the substrate in respective positions that are sequential with respect to a direction transverse to the path of travel. An electric current at each patch element drives radiation of the radio frequency signals and defines a rotating electric current pattern. Respective rotational directions of the electric current pattern at two patch elements are opposite to each other. A radio frequency transmitter drives the antenna to admit the radio frequency signals into 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 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;

an antenna disposed on the frame with respect to the path of travel so that the antenna radiates radio frequency signals into a first area through which the items pass,

wherein the antenna comprises a substrate and a plurality of patch elements disposed on the substrate in respective positions that are sequential with respect to a direction transverse to the path of travel,

wherein electric current at each said patch element drives radiation of the radio frequency signals and defines a rotating electric current pattern, and

wherein respective rotational directions of the electric current pattern at two said patch elements are opposite to each other; and

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

2. The system as in claim 1, wherein the patch elements are spaced apart from each other in the direction transverse to the path of travel.

3. The system as in claim 1, wherein the patch elements are disposed on the substrate in respective positions that are in tandem with respect to the direction transverse to the path of travel.

4. The system as in claim 3, wherein the antenna includes two rows of said patch elements, wherein the patch elements in each row are disposed in tandem with respect to the direction transverse to the path of travel so that the rows are parallel to each other.

5. The system as in claim 4, wherein each row includes three said patch elements.

6. The system as in claim 1, wherein the two patch elements are adjacent to each other.

7. The system as in claim 1, wherein the antenna includes at least one row of said patch elements, wherein the respective rotational directions of the electric current pattern at each pair of adjacent said patch elements are opposite to each other.

8. The system as in claim 1, wherein the at least one row includes four said patch elements.

9. The system as in claim 1, wherein the antenna includes a signal feed network disposed on the substrate and that drives the electric current at the patch elements.

10. The system as in claim 9, wherein signals applied to the patch elements by the feed network and that drive the electric current define a predetermined phase shift at respective said patch elements.

11. The system as in claim 10, wherein the feed network defines an approximately 90 degree phase shift between the signals that drive the electric current at each pair of adjacent said patch elements.

12. 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;

an antenna disposed on the frame beneath the belt and comprising a substrate and a plurality of patch elements disposed on the substrate in respective positions that are sequential with respect to a direction transverse to the path of travel, the antenna being oriented with respect to 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,

wherein electric current at each said patch element drives radiation of the radio frequency signals and defines a rotating electric current pattern, and

wherein respective rotational directions of the electric current pattern at two said patch elements are opposite to each other; and

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

13. The system as in claim 12, wherein the patch elements are spaced apart from each other in the direction transverse to the path of travel.

14. The system as in claim 12, wherein the patch elements are disposed on the substrate in respective positions that are in tandem with respect to the direction transverse to the path of travel.

15. The system as in claim 14, wherein the antenna includes two rows of said patch elements, wherein the patch elements in each row are disposed in tandem with respect to the direction transverse to the path of travel so that the rows are parallel to each other.

16. The system as in claim 15, wherein each row includes three said patch elements.

17. The system as in claim 12, wherein the two patch elements are adjacent to each other.

18. The system as in claim 12, wherein the antenna includes at least one row of said patch elements, wherein the respective rotational directions of the electric current pattern at each pair of adjacent said patch elements are opposite to each other.

19. The system as in claim 12, wherein the at least one row includes four said patch elements.

20. The system as in claim 12, wherein the antenna includes a signal feed network disposed on the substrate and that drives the electric current at the patch elements.

21. The system as in claim 20, wherein signals applied to the patch elements by the feed network and that drive the electric current define a predetermined phase shift at respective said patch elements.

22. The system as in claim 21, wherein the feed network defines an approximately 90 degree phase shift between the signals that drive the electric current at each pair of adjacent said patch elements.

23. The system as in claim 22, wherein the antenna includes at least one row of three of said patch elements.

24. The system as in claim 20, wherein each patch element defines a generally square planar surface at a surface of the substrate.

25. The system as in claim 24, wherein the antenna includes at least one row of said patch elements, wherein the generally square planar surfaces of the patch elements in the at least one row are generally coplanar with each other, wherein the patch elements in the at least one row are aligned in tandem with each other, wherein the feed network applies a respective pair of feed traces to adjacent sides of each said patch element in the at least one row, and wherein signals applied to the patch elements by the respective pair of feed traces drive the electric current and define a predetermined phase shift at the patch elements.

26. The system as in claim 25, wherein the feed network defines an approximately 90 degree phase shift between the signals applied by the respective pair of feed traces at each pair of adjacent said patch elements in the at least one row.

27. 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;

an antenna disposed on the frame beneath the belt and comprising a substrate and a plurality of patch elements having generally planar surfaces and that are disposed on the substrate in respective positions that are sequential with respect to a direction transverse to the path of travel, the antenna being oriented with respect to 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 the generally planar surfaces of the patch elements are generally coplanar,

wherein the antenna includes a feed network that drives electric current at each said patch element to rotate about an axis generally perpendicular to the generally planar surfaces of the patch elements and drive the patch elements to radiate the radio frequency signals,

wherein, for each pair of sequential said patch elements, respective rotational directions of the electric current at the patch elements in the pair are opposite to each other;

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

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

28. The system as in claim 27, wherein signals applied to the patch elements by the feed network and that drive the electric current define a predetermined phase shift at respective said patch elements.

29. The system as in claim 28, wherein the feed network defines an approximately 90 degree phase shift between the signals that drive the electric current at each pair of adjacent said patch elements.

30. The system as in claim 29, wherein the antenna includes at least one row of three of said patch elements.

31. The system as in claim 27, wherein the generally coplanar surfaces of the patch elements are generally square at a surface of the substrate.

32. The system as in claim 31, wherein the antenna includes at least one row of said patch elements, wherein the patch elements in the at least one row are aligned in tandem with each other, wherein the feed network applies a respective pair of feed traces to adjacent sides of each said patch element in the at least one row, and wherein signals applied to the patch elements by the respective pair of feed traces drive the electric current and define a predetermined phase shift at the patch elements.

33. The system as in claim 32, wherein the feed network defines an approximately 90 degree phase shift between the signals applied by the respective pair of feed traces at each pair of adjacent said patch elements in the at least one row.

34. 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;

an antenna disposed on the frame beneath the belt and comprising a substrate and a plurality of patch elements having generally planar surfaces and that are aligned on the substrate in tandem with respect to a direction transverse to the path of travel, the antenna being oriented with respect to 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 the generally planar surfaces of the patch elements are generally coplanar,

wherein the antenna includes a feed network that drives electric current on each said patch element to rotate about an axis generally perpendicular to the generally planar surfaces of the patch elements and drive the patch elements to radiate the radio frequency signals,

wherein, for each pair of adjacent tandem said patch elements, respective rotational directions of the electric current on the patch elements in the pair are opposite to each other;

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

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

35. The system as in claim 34, wherein the antenna includes two parallel rows of said patch elements.

36. The system as in claim 35, wherein each said row includes three said patch elements.

37. The system as in claim 34, wherein the antenna includes at least one row of said patch elements having four said patch elements.

38. The system as in claim 34, wherein signals applied to the patch elements by the feed network and that drive the electric current define a predetermined phase shift at respective said patch elements.

39. The system as in claim 38, wherein the feed network defines an approximately 90 degree phase shift between the signals that drive the electric current at each said pair of adjacent tandem patch elements.

40. The system as in claim 39, wherein the antenna includes at least one row of three of said patch elements.

41. The system as in claim 34, wherein the generally coplanar surfaces of the patch elements are generally square at a surface of the substrate.

42. The system as in claim 41, wherein the antenna includes at least one row of said patch elements, wherein the feed network applies a respective pair of feed traces to adjacent sides of each said patch element in the at least one row, and wherein signals applied to the patch elements by the respective pair of feed traces drive the electric current and define a predetermined phase shift at the patch elements.

43. The system as in claim 42, wherein the feed network defines an approximately 90 degree phase shift between the signals applied by the respective pair of feed traces at each pair of adjacent said patch elements in the at least one row.

44. 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;

an antenna disposed on the frame with respect to the path of travel so that the antenna radiates radio frequency signals into a first area through which the items pass, wherein the antenna comprises a substrate, a first row of a plurality of patch elements having respective generally planar surfaces and that are aligned on the substrate in tandem with respect to a direction transverse to the path of travel, and a second row of a plurality of patch elements having respective generally planar surfaces and that are aligned on the substrate in tandem with respect to the direction transverse to the path of travel,

wherein the generally planar surfaces of the patch elements are generally coplanar,

wherein each said patch element of the first row is aligned in tandem with a corresponding said patch element of the second row in the direction of the path of travel,

wherein electric current at each said patch element rotates about an axis generally perpendicular to the generally planar surfaces of the patch elements and drives the patch elements to radiate the radio frequency signals,

wherein, for each pair of adjacent said patch elements in each of the first and second rows, respective rotational directions of electric current at the patch elements in the pair are opposite to each other, and

wherein the rotational directions of electric current at each pair of said aligned corresponding patch elements of the first row and the second row are the same; and

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

45. The system as in claim 44, wherein each of the first row and the second row includes three said patch elements.

46. The system as in claim 44, wherein each patch element defines at the surface of the substrate a generally square planar surface having opposing truncated corners.

47. The system as in claim 46, wherein the generally square planar surfaces of the patch elements in each of the first row and the second row are generally coplanar with each other, wherein the antenna includes a feed network that applies a respective single feed trace to each patch element that provides signals to the patch element to drive the electric current, wherein the feed network applies the respective single feed trace to each patch element at a side of said patch element with respect to the truncated corners thereof to thereby define the rotational direction of electric current at the patch element, and wherein the signals applied to the patch elements by the respective single feed traces define a predetermined phase shift at the patch elements.

48. The system as in claim 47, wherein the feed network defines an approximately 90 degree phase shift between the signals applied by the respective single feed traces at each said pair of adjacent patch elements.

49. 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;

an antenna disposed on the frame beneath the belt and comprising a substrate, a first row of a plurality of patch elements having respective generally planar surfaces and that are aligned on the substrate in tandem with respect to a direction transverse to the path of travel, and a second row of a plurality of patch elements having respective generally planar surfaces and that are aligned on the substrate in tandem with respect to a direction transverse to the path of travel, the antenna being oriented with respect to 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 the generally planar surfaces of the patch elements are generally coplanar,

wherein each said patch element of the first row is aligned in tandem with a corresponding said patch element of the second row in the direction of the path of travel,

wherein the antenna includes a feed network that drives electric current at each said patch element to rotate about an axis generally perpendicular to the generally planar surfaces of the patch elements and drive the patch elements to radiate the radio frequency signals,

wherein, for each pair of adjacent said patch elements in each of the first and second rows, respective rotational directions of electric current at the patch elements in the pair are opposite to each other, and

wherein the rotational directions of electric current at each pair of said aligned corresponding patch elements of the first row and the second row are the same;

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

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

50. The system as in claim 49, wherein signals applied to the patch elements by the feed network and that drive the electric current define a predetermined phase shift at respective said patch elements.

51. The system as in claim 50, wherein the feed network defines an approximately 90 degree phase shift between the signals that drive the electric current at each said pair of adjacent patch elements.

52. The system as in claim 51, wherein each of the first row and the second row includes three said patch elements.

53. The system as in claim 49, wherein each patch element defines at the surface of the substrate a generally square planar surface having opposing truncated corners.

54. The system as in claim 53, wherein the generally square planar surfaces of the patch elements in each of the first row and the second row are generally coplanar with each other, wherein the feed network applies a respective single feed trace to each patch element that provides signals to the patch element to drive the electric current, wherein the feed network applies the respective single feed trace to each patch element at a side of said patch element with respect to the truncated corners thereof to thereby define the rotational direction of electric current at the patch element, and wherein the signals applied to the patch elements by the respective single feed traces define a predetermined phase shift at the patch elements.

55. The system as in claim 54, wherein the feed network defines an approximately 90 degree phase shift between the signals applied by the respective single feed traces at each said pair of adjacent patch elements.