Abstract:
Methods and systems for programming programmable transponders are disclosed. An apparatus for programming programmable transponders can include a label supply for supplying labels, a programing zone into which the labels are conveyed, a feed-system for transporting a label to the programming zone, a source of radiation for communicating tag-information to the transponder, and a shield mechanism. The source can be disposed to illuminate a programming zone into witch the lable is transported. The shield mechanism can substantially enclose the source of radiation and a first one of the labels in the programming zone and exclude at least a second one of the labels.

Description:
This application is a continuation-in-part application of and claims priority to application Ser. No. 10/843,028, filed May 10, 2004 now U.S. Pat. No. 7,180,419. 

   FIELD OF INVENTION 
   This invention relates to marking products, and in particular, for marking products using programmable transponders. 
   BACKGROUND 
   Current product marking schemes provide only limited information about the identity of a particular package of merchandise. As a result, it is difficult, using only information on the package, to trace mass market products to a particular source. It is even more difficult to trace the path taken by a package of merchandise through the supply chain from a manufacturer, through a chain of distributors, to a retailer. 
   Programmable transponders, such as RFID tags, have sufficient storage capacity to uniquely identify a package of merchandise. Such transponders offer the potential of marking mass-produced packages of merchandise with unique identifiers. The ease with which such transponders can be interrogated has the potential to render practical the task of tracking a package of merchandise through the supply chain. 
   SUMMARY 
   In a general aspect, an apparatus for programming programmable transponders, includes a label supply for supplying labels, each of the labels having a programmable transponder. The apparatus also includes a programming zone into which the labels are conveyed, a feed-system for transporting a label to the programming zone, and a source of radiation for communicating tag-information to the transponder. The source is disposed to illuminate a programming zone into which the label is transported. The apparatus also includes a shield mechanism substantially enclosing the source of radiation and a first one of the labels in the programming zone and excluding at least a second one of the labels, the second one of the labels being adjacent to the first one of the labels. 
   Embodiments may include one or more of the following. The shield mechanism can be configured to allow the source of radiation to program the first one of the labels without programming the second one of the labels. The shield mechanism can include an RF adsorbent material. The shield mechanism can be configured to minimize reflections between the source of radiation and the label. The apparatus can include a testing mechanism configured to test the transponder after the transponder has been exposed to the source of radiation. The apparatus can include applicator disposed adjacent to a tagging zone into which the target is conveyed. Each of the transponders can include an RFID tag. The radiation source can be an antenna. The apparatus can also include a printer disposed adjacent to a printing zone into which the target is conveyed, the printer can be configured to print visible-information on the target, the visible-information corresponding to at least a portion of the tag-information. The printer can be configured to print visible-information on the target indicating a non-functional transponder. The shield mechanism can include a Faraday cage. The shield mechanism can be a box configured to enclose the first one of the labels. 
   In another general aspect, a method for programming programmable transponders includes transporting a label to a programming zone, communicating tag-information to the transponder when the transponder is in the programming zone, and subsequent to communicating the tag-information to the transponder, marking the label with visible information. 
   Embodiments may include one or more of the following. The method can include testing the label to determine if the communication of the tag-information to the transponder was successful. Marking the label with visible information can include marking the label with visible information based on the testing of the label. Marking the label with visible information based on the testing of the label can include marking the label with visible information that is substantially consistent with the tag information if the testing determines that the communication of the tag-information to the transponder was successful. Marking the label with visible information based on the testing of the label can include marking the label with visible information indicating a defective label if the testing determines that the communication of the tag-information to the transponder was not successful. The method can also include automatically removing a label if the testing determines that the communication of the tag-information to the transponder was not successful. The method can also include transporting the label to an applicator disposed adjacent to a tagging zone into which a target is conveyed subsequent to marking the label with visible information and affixing the label to the target when the target is in the tagging zone. Transporting the label to the programming zone can include transporting a strip of labels through the programming zone, the label being affixed to the strip. The method can also include marking the target with visible information, the visible information being consistent with the tag information 

   
     BRIEF DESCRIPTION OF THE FIGURES 
       FIG. 1  shows a marking apparatus in which a transponder is programmed after it is affixed to a target; 
       FIG. 2  shows a marking apparatus in which the transponder is programmed before it is affixed to the target; 
       FIG. 3  shows a marking apparatus in which the printing zone overlaps the application zone; and 
       FIG. 4  shows a label having an RFID tag. 
       FIGS. 5A and 5B  show a shield device. 
       FIG. 6  shows a marking apparatus in which the transponder is programmed before visible information is printed on the tag. 
   

   DETAILED DESCRIPTION 
   The present invention provides a marking apparatus for automatically applying programmable transponders onto a target. The target is typically a unit of merchandise, such as a box containing individual units to be sold at retail, retail packages themselves, or any other item that would be marked with either a label or by imprinting information directly thereon. 
   The programmable transponder is intended to encode information (referred to herein as “tag-information”) about the target to which it is attaches. However, the programmable transponders do not come with tag-information already encoded. As a result, it is necessary to encode tag-information on the transponder and to read back that tag-information to confirm proper programming and operation of the programmable tag. These processes shall be collectively referred to as “programming” the transponder. This extra requirement of programming a transponder is not present in a conventional marking apparatus. 
   In one embodiment, described in connection with  FIG. 1 , the transponder is programmed after having been applied to the target. In other embodiments, described in connection with  FIGS. 2 and 3 , the transponder is programmed before it is applied to the target. In either of these embodiments, an optional printer can be included to imprint a bar code, or human-readable identifying information, that is consistent with the tag-information. Such information is collectively referred to herein as “visible” information. 
   In the embodiments described herein, the programmable transponder is a radio frequency identification (“RFID”) tag on a label that, together with many other labels, is affixed to a flexible strip. Referring to  FIG. 4 , an exemplary label  10  includes an RFID tag having a tag-antenna  14  in electrical communication with a transponder  16  integrated into a semiconductor chip  18 . The label  10  has an adhesive side  20  that adheres to a flexible strip  22 . This adhesive side  20  is also intended to adhere to a target. 
   Referring back to  FIG. 1 , a first embodiment of the marking apparatus  24  features a conveyor-belt  26  driven by a conveyor-motor (not shown) in a downstream direction  28 . At an upstream end of the conveyor-belt  26 , a feed-system  30  driven by a feed-motor (not shown) guides a strip  22  of labels  10  from a label-holder  32  to an applicator  34 . 
   The applicator  34  includes walls defining a cavity in fluid communication with a blower-motor (not shown). One wall of the applicator  34  is a grill  36  that defines a tagging zone at a front side thereof and into which the conveyor-belt  26  conveys a target  38 . The blower-motor is configured to generate a negative pressure to draw air through the grill  36  and into the cavity. Inside the cavity are a plurality of air jets (not shown) oriented to direct compressed air through the grill  36 , toward the tagging zone. An applicator  34  of this type is that sold under the trade name CIMJET 331 by Markem Corporation of Keene, N.H. 
   The feed-system  30  peels the label  10  from the strip  22  so that the adhesive side  20  of the label  10  faces away from the grill  36 , and passes the peeled label  10  to the applicator  34 . A feed-system  30  adaptable for guiding a strip  22  of labels toward the applicator  34  is the CIMJET 300, which is manufactured and sold by Markem Corporation of Keene, N.H. 
   The conveyor-motor, the feed-motor, the blower-motor, and the air jets are all controlled by a processor  40 . In operation, the processor  40  causes the conveyor-motor to drive the conveyor-belt  26 . Meanwhile, the processor  40  causes the feed-motor to drive the feed-system  30  until a peeled label  10  is passed to the applicator  34 . The negative pressure applied by the blower-motor then holds the label  10  against the grill  36  until such time as the conveyor-belt  26  brings a target  38  into the tagging zone. 
   Upon detection of a target  38  approaching the tagging zone, a first edge-detector  42 , positioned upstream of the applicator  34 , sends a trigger signal to the processor  40 . After a brief delay, to allow the conveyor-belt  26  to center the target  38  in the tagging zone, the processor  40  causes the air jets to provide a sudden burst of positive pressure. This blows the label  10  toward the target  38  so that the adhesive side  20  of the label  10  sticks to the target  38 . 
   Downstream from the applicator  34  is a transponder-interface  44  in data communication with the processor  40 . The transponder-interface  44  is in electrical communication with an antenna  46  having a field-of-view oriented to define a programming zone into which the conveyor-belt  26  conveys the target  38 . In this embodiment, the conveyor-belt  26  conveys the target  38  into the programming zone after the target  38  has already been through the tagging zone. As a result, the transponder  16  is affixed to the target  38  before being programmed. 
   A second edge-detector  48 , also in communication with the processor  40 , detects entry of a target  38  into the programming zone. Upon detecting such entry, the second edge-detector  48  provides a trigger signal to the processor  40 . After a brief delay, to allow the conveyor-belt  26  to center the target  38  within the programming zone, the processor  40  causes the transponder-interface  44  to generate an encoding signal to be received by the transponder  16 . 
   The encoding signal has the effect of encoding tag-information in the transponder  16 . The tag-information can include a serial number that uniquely identifies the target  38 . However, the subject matter of the invention does not depend on the particular nature of the tag-information. 
   Before the conveyor-belt  26  can finish conveying the target  38  through the programming zone, the processor  40  causes the transponder-interface  44  to generate an interrogation signal requesting the transponder  16  to identify itself. A transponder  16  that operates correctly will then radiate a response signal containing the tag-information encoded therein. The antenna  46  receives this response signal and provides it to the transponder-interface  44 . The transponder-interface  44  then confirms that the transponder  16  is operating correctly and provides this information to the processor  40 . 
   In some cases, either there is no response signal or the response signal contains erroneous tag-information. In this case, the processor  40  can take several courses of action. It can, for example, stop the conveyor-belt  26  and sound an alarm requesting intervention by an attendant. Or, the processor  40  can actuate an optional arm that pushes the target  38  off the conveyor-belt  26 . 
   In some cases, depending on the nature of the target  38 , the manufacturer may be willing to accept a certain number of defective transponders  16 . In such cases, the processor  40  maintains statistics on the number and frequency of defective transponders  16 . The processor  40  may then be configured to do nothing until either a threshold number of defective transponder is reached, or until the occurrence of defective transponders  16  becomes too frequent. If either of these events occur, the processor  40  can be configured to request intervention by an attendant, or to cause an optional arm to push targets having defective transponders  16  off the conveyor-belt  26 . 
     FIG. 1  also shows an optional printer  50  controlled by the processor  40 . The printer  50  has a printing zone through which the conveyor-belt  26  passes the target  38 . A third edge-detector  52  sends a trigger signal to the processor  40  to indicate entry of the target  38  into the printing zone. 
   As shown in  FIG. 1 , the conveyor-belt  26  passes the target  38  through the printing zone after the target  38  has already passed through the programming zone. However, in other embodiments, the printing zone is upstream from the programming zone or even upstream from the tagging zone. 
   In a marking apparatus  24  having a printer  50 , the processor  40  causes the printer  50  to mark the target  38  with visible-information that corresponds, at least in part, to the tag-information. The printer  50  need not mark the target  38  directly. Instead, the printer  50  can mark the target  38  by printing visible-information on a label and applying that label to the target  38  in a conventional manner. If a target  38  is labeled with a defective transponder  16 , the printer  50  can mark the target  38  with visible-information indicating that the transponder  16  is defective. Examples of label applicators  34  that can be incorporated into the marking apparatus  24  include any of the CIMJET labeling machines sold by Markem Corporation, of Keene, N.H. 
   In some cases, it may not be desirable to apply the label  10  to the target  38  until the transponder  16  has been programmed. This will allow the operation of the transponder  16  to be verified before the label  10  containing the transponder  16  is affixed to the target  38 . An additional embodiment of the marking apparatus  24 , shown in  FIG. 2 , achieves this by having the feed-system  30  guide the strip  22  of labels through the programming zone of the antenna  46 . In this embodiment, a label  10  on the strip  22  passes through the programming zone on its way from the label-holder  32  to the applicator  34 . 
   In the embodiment of  FIG. 2 , a second edge-detector  48 , also in communication with the processor  40 , detects entry of a label  10  into the programming zone. Upon detecting such entry, the second edge-detector  48  provides a trigger signal to the processor  40 . After a brief delay, to allow the transponder  16  to be centered within the programming zone, the processor  40  causes the antenna  46  to radiate an encoding signal and an interrogating signal to the transponder  16 , as discussed in connection with  FIG. 1 . 
   If the transponder  16  fails to respond, or if it responds with erroneous tag-information, the processor  40  can cause the conveyor-belt  26  to move the target  38  away from the tagging zone so that when the defective label  10  reaches the grill  36 , the applicator  34  can blow the defective label  10  across the conveyor-belt  26 , thereby preventing it from being affixed to any target  38 . 
   To avoid having defective labels scattered on the floor nearby, the feed system  30  can include a selective peeling bar to peel the label  10  off the strip  22 . A selective peel bar suitable for incorporation into the feed system  30  is described in a co-owned and concurrently filed patent application entitled “Peel Bar for Selective Label Application,” the contents of which are herein incorporated by reference. 
   Because the labels  10  lie close to each other on the strip  22 , the programming zone may encompass more than one label  10 . When this is the case, the encoding signal may affect more than one transponder  16 . To avoid this, the illustrated embodiment features an antenna  46  enclosed by a Faraday cage  52  having an entrance aperture  54  and an exit aperture  56 . Because the Faraday cage  52  confines electromagnetic radiation within it, the programming zone is restricted to the interior of the cage  52 . 
   The strip  22  is threaded such that it passes through the entrance aperture  54 , into the Faraday cage  52 , and out the exit aperture  56 . The feed-motor drives the strip  22  at a rate such that encoding and interrogation can occur while the label  10  is inside the Faraday cage  52 . The distance between the entrance aperture  54  and exit aperture  56  is selected such that when a label  10  is completely inside the cage  52 , its neighboring labels are outside the cage  52 . This ensures that when a particular transponder  16  is programmed, the neighboring transponders remain unaffected. 
   As noted above, by having the same processor  40  control both the printer  50  and the transponder-interface  44 , the visible-information on a target  38  can easily be made consistent with the tag-information. However, when the printing zone and the programming zone are separated from each other, the marking apparatus  24  can mistakenly label the target  38  with visible-information that is inconsistent with the tag-information. This may occur, for example, if a target  38  falls off the conveyor-belt  26 , or if a target  38  that has fallen off the conveyor-belt  26  is inadvertently replaced out of sequence. 
   To avoid inconsistency between the visible-information and the tag-information, another embodiment of the marking apparatus  24  features a printer  50  disposed such that the printing zone and the tagging zone at least partially overlap, as shown in  FIG. 3 . In this case, only the first edge-detector  42  is necessary. A marking apparatus  24  such as that shown in  FIG. 3 , in which application of the label  10  and the printing of visible-information occur without having to move the target  38 , reduces the likelihood of an inconsistency between the tag-information and the visible-information. 
   While the embodiments described herein encode tag-information in an RFID tag, the invention does not depend on the particular type of transponder  16  that is attached to the label  10 . In fact, the scope of the invention is circumscribed only by the appended claims. 
   In some embodiments, as shown in  FIGS. 5A and 5B , RF adsorbent materials  53  can be disposed along the walls of the cage  52 . The RF use of RF adsorbent materials can minimize unwanted reflections of the encoding signal. 
   In the embodiment of  FIG. 6 , in addition to or instead of marking the target  38  with visible information corresponding to the tag-information, the label  10  is marked with visible information. In such embodiments, the label  10  enters the programming zone and the computer  40  detects the entry of a label  10  into the programming zone. Upon detecting such entry, after a brief delay, the computer  40  causes the antenna  46  to radiate an encoding signal. Processor  40  also causes the antenna  46  to radiate interrogating signal to the transponder  16 . As discussed in connection with  FIG. 1 , the interrogating signal reads back that tag-information to confirm proper operation of the programmable tag. This allows the operation of the transponder  16  to be verified before the label  10  containing the transponder  16  is printed and affixed to the target  38 . 
   Subsequent to the programming of label  10 , label  10  is transported to a label printing zone. The label printing zone can be disposed adjacent to the programming zone or the label printing zone can be integral with the programming zone. While in the label printing zone, the printer  70  can print various visible information onto the label  10 . For example, the visible information printed on label  10  can correspond to the tag-information encoded on the tag. 
   In some embodiments, the printer  70  prints various messages on the labels  10  to indicate whether the tag has been successfully encoded. For example, if the transponder  16  failed to respond, or if it responded with erroneous tag-information, the printer  70  can apply a marking indicating that the label is not good. On the other hand, if the transponder  16  responded with the correct tag-information, the printer can apply a marking that includes the desired information corresponding, at least in part, to the tag-information encoded on the label  10 . Thus, a single printer  70  marks both labels that have been successfully encoded and labels that have not been successfully encoded. 
   While in the embodiment described above the printer applied a marking to indicate that a label was not good, alternatively the printer can skip printing on the defective label and print information only on the labels which have been successfully encoded.