RFID conveyor system and method

• US 7,557,713 B2
• Filed: 03/23/2006
• Issued: 07/07/2009
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Datalogic USA, Inc.
• Original Assignee: Accu-Sort Systems Incorporated (Datalogic S.p.A.)
• Inventors: Cox, James N.
• Primary Examiner(s): TWEEL JR, JOHN ALEXANDER
• Application Number:
  US11/388,099
• Publication Number:
  US 20060244610A1
• Time in Patent Office: 1,202 Days
• Field of Search: 340/572.7, 340/572.1, 340/572.4, 340/10.1, 340/10.3, 235/385, 235/384, 343/742, 343/866, 343/867
• US Class Current: 340/572.7
• 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 includes a plurality of antennas proximate a conveyor path of travel that radiate radio frequency signals into a first area and receive responses to radio frequency signals from radio frequency identification tags on items on the conveyor. A detector detects a height of items. A processor receives response signals from the receiver and controls a transmitter to drive respective antennas in a predetermined sequence, associate a response with a first item if the processor receives the response 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 based on signals from the detector, eliminate at least one of the plurality of antennas from the predetermined sequence if the height of the first item is below a predetermined threshold.

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;

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

radiate radio frequency signals into a first area through which the items pass and

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

wherein at least one of the plurality of antennas is disposed so that the items pass through the path of travel between the conveyor and the at least one of the plurality of antennas;

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

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;

a detector disposed with respect to the path of travel so that second signals output by the detector indicate a height of items passing proximate the detector through the path of travel, and

a processor that receives the first signals from the at least one receiver,

wherein the processor is programmed to

control the at least one transmitter to drive said antennas in a predetermined sequence with respect to each other,

associate a said first signal with a first said item based upon whether the processor receives the first signal from the at least one 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

based on the second signals, eliminate the at least one of the plurality of antennas from the predetermined sequence when the first item is within the second area if the height of the first item is below a predetermined threshold.

2. 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 a first area that is 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 at least one of the plurality of antennas is disposed with respect to the belt so that the items pass through the path of travel between the belt and the at least one of the plurality of antennas;

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

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;

a detector disposed with respect to the belt so that second signals output by the detector indicate a height of items on the belt passing proximate the detector, and

a processor that receives the first signals from the at least one receiver,

wherein the processor is programmed to

control the at least one transmitter to drive said antennas in a predetermined sequence with respect to each other,

associate a said first signal with a first said item based upon whether the processor receives the first signal from the at least one 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

based on the second signals, eliminate the at least one of the plurality of antennas from the predetermined sequence when the first item is within the second area if the height of the first item is below a predetermined threshold.

3. The system as in claim 2, wherein each said response includes information that identifies the radio frequency identification tag from which said response is received, wherein each first signal includes the information in its corresponding response, and wherein the processor is programmed to associate the information included in the first signal with the first item if the processor receives the last-mentioned first signal while at least a portion of the first item is within the second area.

4. The system as in claim 2, wherein each said antenna both radiates the radio frequency signals and receives the responses.

5. The system as in claim 4, including four said antennas, respectively disposed on a first side of the belt opposite a second side of the belt on which the items are conveyed, the second side of the belt, a third side of the belt laterally offset from the belt with respect to the path of travel, and a fourth side of the belt laterally offset from the belt opposite the third side.

6. 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 conveyor that is disposed movably on a frame, said method comprising the steps of:

driving a plurality of antennas disposed so that each antenna

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

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

wherein at least one of the plurality of antennas is disposed with respect to the conveyor so that the items pass through the path of travel between the conveyor and the at least one of the plurality of antennas;

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 a height of items on the conveyor;

driving said antennas in a predetermined sequence with respect to each other;

associating a said first signal with a first said item based upon whether the first signal is received from the at least one 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

based on the height detected at the detecting step, eliminating the at least one of the plurality of antennas from the predetermined sequence when the first item is within the second area if the detected height of the first item is below a predetermined threshold.

7. The method as in claim 6, wherein the conveyor is a generally planar belt.

8. The method as in claim 7, wherein the driving step includes providing four said antennas, respectively disposed on a first side of the belt opposite a second side of the belt on which the items are conveyed, the second side of the belt, a third side of the belt laterally offset from the belt with respect to the path of travel, and a fourth side of the belt laterally offset from the belt opposite the third side.

9. 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 antennas communicate with radio frequency identification tags on said items conveyed by the conveyor through the path of travel, wherein at least one of the plurality of antennas is disposed so that the items pass through the path of travel between the conveyor and the at least one of the plurality of antennas;

at least one radio frequency transmitter that drives the antennas to communicate with the radio frequency identification tags;

a radio frequency receiver in communication with the antennas so that the receiver reads the radio frequency identification tags via the antennas;

a detector disposed with respect to the path of travel so that the detector detects a height of items passing proximate the detector through the path of travel; and

a processor in communication with the receiver and the detector,

wherein the processor is programmed to

control the at least one transmitter to drive said antennas in a predetermined sequence with respect to each other,

associate information read from a first said radio frequency identification tag by the receiver with a first said item based upon whether the receiver reads the first radio frequency identification tag while at least a portion of the first item is within a predefined first area that is proximate the path of travel and through which the items pass, and

responsive to the detector, eliminate the at least one of the plurality of antennas from the predetermined sequence when the first item is within the second area if the height of the first item is below a predetermined threshold.

10. The system as in claim 9, including four said antennas, respectively disposed on a first side of the conveyor opposite a second side of the conveyor on which the items are conveyed, the second side of the conveyor, a third side of the conveyor laterally offset from the conveyor with respect to the path of travel, and a fourth side of the conveyor laterally offset from the conveyor opposite the third side.

11. The system as in claim 10, wherein the at least one of the plurality of antennas is the antenna disposed on the second side of the conveyor.