|Publication number||US20050045724 A1|
|Application number||US 10/707,895|
|Publication date||Mar 3, 2005|
|Filing date||Jan 21, 2004|
|Priority date||Aug 29, 2003|
|Also published as||CN1863681A, CN100464991C, EP1820659A2, EP1820659A3, EP1820659B1, EP2266807A1, EP2266808A1, EP2266808B1, EP2272680A2, US7398054, US7650114, US8160493, US8351959, US20050045723, US20090008448, US20100067054, US20120176224, US20140002243|
|Publication number||10707895, 707895, US 2005/0045724 A1, US 2005/045724 A1, US 20050045724 A1, US 20050045724A1, US 2005045724 A1, US 2005045724A1, US-A1-20050045724, US-A1-2005045724, US2005/0045724A1, US2005/045724A1, US20050045724 A1, US20050045724A1, US2005045724 A1, US2005045724A1|
|Inventors||Boris Tsirline, Clive Hohberger, Robert Gawelczyk, Daniel Donato|
|Original Assignee||Zih Corp.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (26), Referenced by (39), Classifications (19), Legal Events (1)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This application is a continuation-in-part of U.S. Utility Patent application No. 10/604,996, filed Aug. 29,2003 and hereby incorporated by reference in the entirety.
1. Field of the Invention
The invention relates to RFID systems, operable with a variety of different dimensioned electro-magnetically coupled transponders, working at close proximity, to an RF transceiver antenna that is spatially selective for an individual transponder located in a predetermined transponder operating region to the exclusion of other adjacent transponders, and its application to printers-encoders or other systems utilizing such in UHF RFID systems.
2. Description of Related Art
UHF radio frequency identification (RFID) technology allows wireless data acquisition and or transmission from and or to active (battery powered) or passive transponders using a backscatter technique. To communicate with, i.e., “read” from and or “write” commands and/or data to a transponder, the transponder is exposed to an RF electromagnetic field by the transceiver that couples with and energizes (if passive) the transponder through electro-magnetic induction and transfers commands and data using a predefined “air interface” RF signaling protocol.
When multiple passive transponders are within the range of the same RF transceiver electro-magnetic field they will each be energized and attempt to communicate with the transceiver, potentially causing errors in “reading” and or “writing” to a specific transponder in the reader field. Anti-collision management techniques exist to allow near simultaneous reading and writing to numerous closely grouped transponders in a common RF electro-magnetic field. However, anti-collision management increases system complexity, cost and delay response. Furthermore, anti-collision management is “blind” in that it cannot recognize where a specific transponder being processed is physically located in the RF electro-magnetic field, for example, which transponder is located proximate the print head of a printer-encoder.
One way to prevent errors during reading and writing to transponders without using anti-collision management is to electrically isolate a specific transponder of interest from nearby transponders. Previously, isolation of transponders has used RF-shielded housings and/or anechoic chambers through which the transponders are individually passed for personalized exposure to the interrogating RF field. This requires that the individual transponders have cumbersome shielding or a significant spatial separation.
RFID printers-encoders have been developed which are capable of on-demand printing on labels, tickets, tags, cards or other media with which a transponder is attached or embedded. These printer-encoders have a transceiver for on-demand communicating with the transponder on the individual media to read and/or store data into the attached transponder. For the reasons given, it is highly desirable in many applications to present the media on rolls or other format in which the transponders are closely spaced. However, close spacing of the transponders exacerbates the task of serially communicating with each individual transponder without concurrently communicating with neighboring transponders on the media. This selective communication exclusively with an individual transponder is further exacerbated in printers-encoders designed to print on the media in or near the same space as the transponder is positioned when being interrogated.
When transponders are supplied attached to a carrier substrate, for example in RFID-attached labels, tickets, tags or other media supplied in bulk rolls, Z-folded stacks or other format, an extra length of the carrier substrate is required to allow one transponder on the carrier substrate to exit the isolated field area before the next transponder in line enters it. The extra carrier substrate increases materials costs and the required volume of the transponder media bulk supply for a given number of transponders. Having increased spacing between transponders may also slow overall printer-encoder throughput.
When transponders of different sizes and form factors are processed, the RF shielding and or anechoic chamber configuration will also require reconfiguration, adding cost, complexity and reducing overall productivity. In certain printer-encoders it is desired to print on transponder-mounting media in the same transponder operating region in which the transponder is being read from or written to. This may be very difficult to accomplish if the transponder also must be isolated in a shielded housing or chamber.
UHF transponders may operate in, for example, the 902-928 MHz band in the United States and other ISM bands designated in different parts of the world. For example, in
As shown by
Thus the minimum required spacing of these transponders 1 to isolate them, and thus the minimum size of media 11 (assuming that they are embedded one per label or media 11 on carrier substrate 13) must be large relative to the size of the microstrip coupler 3. This creates issues for media suppliers by limiting the available space on the media 11 for transponder 1 placement and significantly increasing the necessary accuracy of the transponder 1 placement within and or under the printable media 11 and along the liner or carrier substrate 13. This also reduces the cost advantages of using the narrow dimensioned transponder(s) 1 within media 11, as the media 11 must be much larger than the transponder 1 to achieve adequate RF isolation.
Competition in the market for such “integrated” printer-encoder systems as well as other RFID interrogation systems has focused attention on the ability to interrogate with high spatial selectivity any transponder from a wide range of available transponders having different sizes, shapes and coupling characteristics as well as minimization of overall system, media size and transponder costs.
Therefore, it is an object of the invention to provide a device, systems and methods that overcome deficiencies in such prior art.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description of the embodiments given below, serve to explain the principles of the invention.
The present invention concerns apparatus and method which enables an RFID transceiver (sometimes termed herein an “interrogator”) to communicate selectively and exclusively with a single UHF transponder 1 when one or more other similar transponders are in close proximity, without the need for physical isolation or cumbersome shielded housings or chambers.
The invention is useful in the reading and or data loading of UHF transponders, for example on an assembly line, in distribution centers or warehouses where on-demand RFID labeling is required, and in a variety of other applications. In many applications a transponder or a number of transponders are mounted or embedded on or in a label, ticket, tag, card or other media carried on a liner or carrier. It is often desirable to be able to print on the media before, after, or during communication with a transponder. Although this invention is disclosed here in a specific embodiment for use with a direct thermal or thermal transfer printer, it may also be used with any type of spatially selective RFID interrogation device or other types of printers using other printing technologies, including inkjet, dot-matrix, and electro-photographic methods.
In some applications a print station may be at a distance from the RFID transceiver; in others it may be necessary to accomplish the print function in the same target space occupied by the transponder when it is being interrogated.
When a thermal printer is configured for use as a thermal transfer printer, a ribbon supply roll 28 delivers a thermal transfer ribbon (not shown for clarity) between printhead 14 and the media on web 24. After use, the spent ribbon is collected on a take-up reel 22.
In accordance with an aspect of the present invention, the media printer 16 includes a transceiver 42 for generating RF communication signals that are fed to a frequency and spatially selective microstrip near field coupler 30 located proximate the media feed path 26. As will be explained and illustrated in detail hereinafter, the system (including transceiver 42 and near field coupler 30) forms a near field pattern in the location of a transponder operating region C (see
As labels or other media 11 with embedded transponders 1 move along the media feed path 26 through transponder operating region “C”, data may be read from and or written to each transponder 1. Information indicia then may be printed upon an external surface of the media 11 as the media passes between the platen roller 19 and the printhead 18 by selective excitation of the heating elements in the printhead 18, as is well known in the art. When the media printer 16 is configured as a direct thermal printer, the heating elements form image dots by thermochromic color change in the heat sensitive media; when the media printer 16 is configured as a thermal transfer printer, then ink dots are formed by melting ink from the thermal transfer ribbon (not shown for clarity) delivered between printhead 18 and the media on web 24 from ribbon supply roll 28. Patterns of printed dots thus form the desired information indicia on the media 11, such as text, bar codes or graphics.
Media conveyance is well known in the art. Therefore the media conveyance 25 portion of the printer that drives the media with transponders along the media feed path 26 is not described in detail.
The near field coupler 30 according to the invention and its manner of operation will now be described with reference to
The near field coupler 30 comprises an array of lines 50, as shown for example in
Rather than operating as a standing wave radiating antenna, or magnetic field generating coil, the near field coupler 30 according to the invention operates as a one half wavelength unmatched transmission line with, for example, a 15 ohm characteristic impedance that is terminated by a R=50 ohm terminating resistor 8. Signals generated by the transceiver 42 passing along the transmission line generate a near field effect emanating from the transmission line edges that couples with a transponder 1 passing through the transponder operating region. Another description for the near field effect is “leaky”, as discussed in “Leaky Fields on Microstrip” L.O. McMillian et al. Progress in Electromagnetics Research, PIER 17, 323-337, 1997 and hereby incorporated by reference in the entirety. Because the near field effect is extremely local to the transmission line and degrades at an exponential rate with increasing distance from the transmission line, the resulting transponder operating region of a single transmission line is very narrow. According to the invention, the prior rectangular conductive strip is therefore replaced with an array formed by a plurality of commonly fed and terminated, i.e. electrically parallel, line(s) 50, as shown for example in
As shown by
In some applications, for example the modification of an existing printer configuration to add RFID read / write capability, the coupler 30 may be placed close to the web 24 due to available space and or other design considerations such as placement of the transponder operating region C proximate the printhead 18. Where the coupler 30 and the web 24 are at a close proximity to one another an impedance mismatch may occur as electrical interaction with passing transponder(s) 1 varies the effective impedance of the coupler 30. Impedance mismatch will decrease coupling range for a given output power and with significant impedance variances may cause narrow null gaps in the operational region C, for example as illustrated by d, e, f, and g in
Simplified logic added to the media transport system may be used to move the media 11 forward a small increment, for example 1-2 millimeters if a transponder 1 in the transponder operating region C falls upon a null gap and transponder communications is lost.
The null gaps and the ability to control their presence by manipulating the location of the coupler 30 with respect to the web 24, are evidence of the extremely local field concentrations produced by the near field effect and the precision with which the transponder operating region may be configured to have a wide area with sharply defined boundaries. These characteristics make the near field coupler 30 useful for eliminating precision transponder placement requirements for media suppliers, complex transponder location and tracking logic in media supply systems, as well as any requirements for shielding or increased transponder placement tolerance requirements. Further, the increased transponder operating region C provided by the present invention allows users increased freedom to place embedded transponder(s) 1 in media 11 at desired locations, for example to avoid the printing degradation that may occur when the printhead encounters a media surface irregularity due to the presence of a RFID transponder 1.
The array of lines 50 of the near field coupler 30 may be formed by a plurality of straight line(s) 50 as shown in
Alternatively, a simplified transponder 1 read and or write system may be formed without printing capabilities by positioning a near field coupler 30 coupled to a transceiver 42 proximate a media conveyance 25 moving sequential transponders 1 through a transponder operating region C. This structure is also useful where the media 11 is unprinted, or printed upon at another location.
The near field coupler 30 is not limited to a dual plane structure. For example, the near field coupler 30 may be co-planar, i.e. the ground plane and the array of lines 50 may be located, electrically isolated from each other, in the same plane of a printed circuit board but on different traces. Also, the lines 50 need not be co-planar, but may form a 3-dimensional structure. For example, the lines 50 may be on multiple layers of a printed circuit board or formed as a wire frame of lines 50 without use of printed circuit board technology.
Obviously, at some exaggerated transceiver power level, certain transponders 1 outside the transponder operating region C may be excited. However, by this invention, at appropriate power levels in the range of normal transponder read and write power levels the mutual coupling created will be highly selective for the transponder 1 in the transponder operating region C. By mapping and then applying only the required power levels for a range of both different transponder 1 types and positions within the transponder operating region C, energy consumption and potential RF interference generation may be minimized.
The spatially-selective near field property and the lack of any other shielding requirements of the near field coupler 30 according to the invention allows the economical addition of a compact, spatially-selective transponder communication module in devices such as printer-encoders.
Because the near field coupler 30 may be configured to be selective exclusively for a single transponder located in the transponder operating region C, it is now possible by this invention to use a web 24 of media having transponders which are closely spaced on the web 24, as shown for example in the figures of this specification. Prior to this invention it was extremely difficult to communicate with just one electro-magnetically-coupled UHF transponder, which may have a wide number of different physical configurations, in a closely spaced series of transponders without simultaneously activating adjacent transponders.
Table of Parts 1 transponder 3 prior art coupler 5 conductive strip 7 printed circuit board 8 terminating resistor 9 ground plane 10 electro-magnetic power leakage 11 media 13 carrier substrate 16 media printer 18 printhead 19 platen roller 22 take up reel 24 web 25 media conveyance 26 feed path 28 ribbon supply roll 30 near field coupler 32 tear bar 34 media exit path 36 roller 38 carrier exit path 42 transceiver 50 line
Where in the foregoing description reference has been made to ratios, integers or components having known eqivalents then such equivalents are herein incorporated as if individually set forth.
While the present invention has been illustrated by the description of the embodiments thereof, and while the embodiments have been described in considerable detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative apparatus, methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departure from the spirit or scope of applicant's general inventive concept. Further, it is to be appreciated that improvements and/or modifications may be made thereto without departing from the scope or spirit of the present invention as defined by the following claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4509039 *||Jul 5, 1983||Apr 2, 1985||Minnesota Mining And Manufacturing Company||Shielded, closely spaced transmit-receiver antennas for electronic article surveillance system|
|US5278571 *||Oct 16, 1991||Jan 11, 1994||Tel Instrument Electronics Corp.||RF coupler for measuring RF parameters in the near-field|
|US5294931 *||Apr 29, 1992||Mar 15, 1994||Texas Instruments Deutschland Gmbh||Method of interrogating a plurality of transponders arranged in the transmission range of an interrogating device and transponders for use in the said method|
|US5369381 *||May 27, 1991||Nov 29, 1994||U.S. Philips Corporation||Slow-wave transmission line of the microstrip type and circuit including such a line|
|US5373266 *||Nov 9, 1993||Dec 13, 1994||The United States Of America As Represented By The Secreatry Of The Army||Microstrip directional coupler|
|US5587578 *||Aug 9, 1995||Dec 24, 1996||Gemplus||Method and apparatus for optimizing magnetic flux through an electronic label of a contact-free identification system|
|US5777586 *||May 29, 1997||Jul 7, 1998||Luxon; Norval N.||Radiation shielding and range extending antenna assembly|
|US5838253 *||May 17, 1995||Nov 17, 1998||Accu-Sort Systems, Inc.||Radio frequency identification label|
|US6104291 *||Oct 6, 1998||Aug 15, 2000||Intermec Ip Corp.||Method and apparatus for testing RFID tags|
|US6181287 *||Mar 3, 1998||Jan 30, 2001||Precision Dynamics Corporation||Reactively coupled elements in circuits on flexible substrates|
|US6246326 *||May 5, 1999||Jun 12, 2001||Intermec Ip Corp.||Performance optimized smart label printer|
|US6287521 *||Feb 20, 1998||Sep 11, 2001||Atossa Healthcare, Inc.||Methods and devices for obtaining and assaying mammary fluid samples for evaluating breast diseases, including cancer|
|US6327972 *||Oct 7, 1999||Dec 11, 2001||Meto International Gmbh||Printer with a device for the driving of transponder chips|
|US6392544 *||Sep 25, 2000||May 21, 2002||Motorola, Inc.||Method and apparatus for selectively activating radio frequency identification tags that are in close proximity|
|US6409401 *||Mar 26, 2001||Jun 25, 2002||Zih Corp.||Portable printer with RFID encoder|
|US6473028 *||Apr 5, 2000||Oct 29, 2002||Stmicroelectronics S.A.||Detection of the distance between an electromagnetic transponder and a terminal|
|US6527356 *||Jun 2, 2000||Mar 4, 2003||Eastman Kodak Company||Printer capable of forming an image on a receiver substrate according to type of receiver substrate and a method of assembling the printer|
|US6593853 *||Feb 18, 2000||Jul 15, 2003||Brady Worldwide, Inc.||RFID label printing system|
|US6857714 *||Oct 25, 2001||Feb 22, 2005||Zih Corp.||Method and apparatus for associating on demand certain selected media and value-adding elements|
|US6929412 *||Jun 7, 2004||Aug 16, 2005||Printronix, Inc.||RFID tag, antenna, and printer system|
|US7023391 *||May 17, 2001||Apr 4, 2006||Stmicroelectronics S.A.||Electromagnetic field generation antenna for a transponder|
|US20020003498 *||May 17, 2001||Jan 10, 2002||Luc Wuidart||Electromagnetic field generation antenna for a transponder|
|US20020167397 *||Jul 8, 1999||Nov 14, 2002||Kursat Eroglu||Method and apparatus for verifying rfid tags|
|US20030067504 *||Oct 10, 2002||Apr 10, 2003||Spurr Robert W.||Printer capable of forming an image on a receiver substrate according to type of receiver substrate and a method of assembling the printer|
|US20040178267 *||Mar 11, 2003||Sep 16, 2004||Zebra Technologies Corporation||System and Method for Selective Communication with RFID Transponders|
|US20040195319 *||Apr 3, 2003||Oct 7, 2004||Forster Ian J.||RFID device detection system and method|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7295117||Apr 7, 2005||Nov 13, 2007||Avery Dennison||RFID device test thresholds systems and methods|
|US7298266||May 9, 2005||Nov 20, 2007||Avery Dennison||RFID communication systems and methods|
|US7298267||May 9, 2005||Nov 20, 2007||Avery Dennison||RFID test interface systems and methods|
|US7359823||May 25, 2005||Apr 15, 2008||Avery Dennison||RFID device variable test systems and methods|
|US7398926 *||Oct 6, 2003||Jul 15, 2008||Applied Wireless Identifications Group, Inc.||Apparatus and method for programming an RFID transponder using a constrained field|
|US7411498||Apr 7, 2005||Aug 12, 2008||Avery Dennison||RFID testing and classification systems and methods|
|US7425887||Sep 21, 2005||Sep 16, 2008||Zih Corporation||Multi-layered efficient RFID coupler|
|US7551087||Oct 17, 2006||Jun 23, 2009||Adasa, Inc.||Handheld and cartridge-fed applicator for commissioning wireless sensors|
|US7650114 *||Jun 5, 2008||Jan 19, 2010||Zih Corp.||Spatially selective UHF near field microstrip coupler device and RFID systems using device|
|US7671805||May 11, 2007||Mar 2, 2010||Kabushiki Kaisha Toshiba||Antenna apparatus and article management system|
|US7830258||Aug 18, 2006||Nov 9, 2010||Adasa, Inc.||Systems, methods, and devices for converting and commissioning wireless sensors|
|US7832952 *||Sep 14, 2007||Nov 16, 2010||Avery Dennison Corporation||High-frequency RFID printer|
|US7839287||Mar 30, 2007||Nov 23, 2010||Zih Corp.||Near-field miniature coupler|
|US8078103||Oct 31, 2005||Dec 13, 2011||Zih Corp.||Multi-element RFID coupler|
|US8159349||Sep 28, 2010||Apr 17, 2012||Adasa Inc.||Secure modular applicators to commission wireless sensors|
|US8160493||Nov 24, 2009||Apr 17, 2012||Zih Corp.||Spatially selective UHF near field microstrip coupler device and RFID systems using device|
|US8228198||Jun 21, 2010||Jul 24, 2012||Adasa Inc.||Systems, methods, and devices for commissioning wireless sensors|
|US8254833||May 11, 2009||Aug 28, 2012||Zih Corp.||Near field coupling devices and associated systems and methods|
|US8306474 *||Nov 18, 2011||Nov 6, 2012||Zih Corp.||Multi-element RFID coupler|
|US8351959||Mar 16, 2012||Jan 8, 2013||Zih Corp.||Spatially selective UHF near field microstrip coupler device and RFID systems using device|
|US8358246||Jul 27, 2007||Jan 22, 2013||Zih Corp.||RFID UHF stripline antenna-coupler|
|US8544740||Aug 22, 2011||Oct 1, 2013||Zih Corp.||Apparatus and method for communicating with an RFID transponder|
|US8565677||Jul 25, 2012||Oct 22, 2013||Zih Corp.||Near field coupling devices and associated systems and methods|
|US8596532||May 3, 2005||Dec 3, 2013||Zih Corp.||Apparatus and method for communicating with an RFID transponder|
|US8791874||Sep 16, 2013||Jul 29, 2014||Zih Corp.||Near field coupling devices and associated systems and methods|
|US8870478 *||May 30, 2007||Oct 28, 2014||Zih Corp.||Media processing system and associated spindle|
|US8878652||Nov 13, 2009||Nov 4, 2014||Zih Corp.||Encoding module, associated encoding element, connector, printer-encoder and access control system|
|US9108434||Dec 18, 2007||Aug 18, 2015||Zih Corp.||RFID near-field antenna and associated systems|
|US20050274799 *||May 3, 2005||Dec 15, 2005||Zih Corp.||Apparatus and method for communicating with an RFID transponder|
|US20060087415 *||Sep 15, 2005||Apr 27, 2006||Meta System - S.P.A.||Obstacle detection method and system, particularly for systems for assisting the parking of vehicles|
|US20060226982 *||Apr 7, 2005||Oct 12, 2006||Forster Ian J||RFID testing and classification systems and methods|
|US20060250245 *||May 9, 2005||Nov 9, 2006||Forster Ian J||RFID communication systems and methods|
|US20060250246 *||May 9, 2005||Nov 9, 2006||Forster Ian J||RFID test interface systems and methods|
|US20070040684 *||Aug 18, 2006||Feb 22, 2007||Mcallister Clarke W||Systems, methods, and devices for converting and commissioning wireless sensors|
|US20070063843 *||Sep 21, 2005||Mar 22, 2007||Zih Corp.||Multi-layered efficient RFID coupler|
|US20120108170 *||Nov 18, 2011||May 3, 2012||Zih Corp.||Multi-element rfid coupler|
|EP2261835A1||Oct 31, 2006||Dec 15, 2010||ZIH Corporation||Multi-element RFID coupler|
|EP2261836A1||Oct 31, 2006||Dec 15, 2010||ZIH Corporation||Method of communicating with a targeted transponder|
|WO2009048007A1||Oct 1, 2008||Apr 16, 2009||Sanyo Chemical Ind Ltd||Method for producing fine particle-dispersed polyol and method for producing polyurethane resin|
|U.S. Classification||235/451, 235/432|
|International Classification||G06K7/08, G06K7/00, G06K7/10, G06K1/12|
|Cooperative Classification||G06K7/10079, G06K7/10336, G06K7/10346, G06K7/10366, G06K7/0008, G06K1/12, G06K17/0025|
|European Classification||G06K7/10A8E, G06K17/00G1, G06K7/10A8C, G06K7/10A1E, G06K1/12, G06K7/00E|
|Jan 21, 2004||AS||Assignment|
Owner name: ZIH CORP., BERMUDA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:TSIRLINE, BORIS Y;HOHBERGER, CLIVE P;GAWELCZYK, ROBERT;AND OTHERS;REEL/FRAME:014276/0287
Effective date: 20040115