Abstract:
Maintaining faulty radio frequency identification (RFID) labels on a surface of a web carrier. The various embodiments of the invention provide apparatus for controlling whether RFID labels are separated from a label web. In one embodiment, a frame has first and second side members, and a peel bar is mounted between the first and second side members. The peel bar has a radial portion that causes an RFID label to be separated from the surface of the web carrier as the web carrier contacts and travels over the radial portion. A cam bar is mounted on the frame and is rotatable. In a first position the cam bar causes the web carrier to contact and travel at least partially around the radial portion of the peel bar, and in a second position the cam bar prevents the web carrier from contacting and traveling at least partially around the radial portion of the peel bar.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to dispensing of Radio Frequency IDentification (RFID) labels. 
     BACKGROUND 
     Label dispensing units for applying labels to advancing articles have come into widespread use in a variety of industries. Print-and-apply label dispensing systems are today&#39;s cost-effective solution for labeling products, cartons, cases, and pallets. Generally, these types of systems feature a unique modular design that couples a variety of commercially available print engine modules to one of several label applicators through a standard chassis. In operation, the print-and-apply label dispensing system produces high quality, “on-demand” labels and applies them automatically in a single, easy operation to advancing articles. Exemplary print engine modules are commercially available from Sato America, Inc. of Sunnyvale, Calif.; Zebra Technologies, Inc. of Vernon Hills, Ill.; and Datamax Corporation of Orlando, Fla. 
     Regardless of which print engine module is used, the label application process involves a series of roller assemblies. These roller assemblies control and guide the movement of the label web through the label dispensing unit. The application process involves changing the travel direction of the label web abruptly enough to impose a peel angle on the label web, which effectively separates the labels from the web for application to articles conveyed past the dispensing unit. The particular peel angle and the configuration of roller assemblies depends upon the label web and specific print engine module. The discarded label web is collected on a take-up roller. 
     The use of labels on products has evolved from merely being a manner of identification to being an important tool in inventory tracking and management. One major development in labeling was the introduction of bar codes on labels. Bar codes are used on a majority of products found in both retail stores and warehouses and are used to quickly and easily track inventory. Today, manufacturers are increasingly using a new, alternative inventory tracking label that incorporates Radio Frequency IDentification (RFID) technology. RFID involves remotely storing and retrieving data using devices called RFID tags or transponders. An RFID tag is a small object, such as an adhesive sticker (label), that can be attached to or incorporated into a product. RFID tags can receive and respond to radio-frequency-based queries from an RFID transceiver. Some advantages of RFID tags over bar codes include: detection without human intervention; placement inside other packaging; readability without being visible; readability may be less succeptible to being impaired by dirt, moisture, abrasion, or packaging contours; and the capability to both read and write to the tags. These improvements in label technology are accompanied, however, by a corresponding increase in the cost to those who use the labels. 
     The cost of RFID labels may provide an incentive for a user to prevent wasting labels. Ideally all RFID labels on a label web are functional and may be applied to the user&#39;s articles. However, in some circumstances an RFID label may be faulty and therefore unusable. Instead of discarding faulty labels, a user may wish to return them to the vendor or manufacturer of the labels for a refund or credit. However, the vendor or manufacturer may require that the returned RFID labels be physically preserved in order to verify that the labels are actually faulty. 
     SUMMARY 
     The present invention is directed to the above and related types of systems for application of RFID labels. 
     In one embodiment, an apparatus is provided for controlling whether RFID labels are separated from a label web carrier. A frame has first and second side members, and a peel bar is mounted between the first and second side members. The peel bar has a radial portion that causes an RFID label to be separated from the surface of the web carrier as the web carrier contacts and travels over the radial portion. A cam bar is mounted on the frame and is rotatable. In a first position the cam bar causes the web carrier to contact and travel at least partially around the radial portion of the peel bar, and in a second position the cam bar prevents the web carrier from contacting and traveling at least partially around the radial portion of the peel bar. 
     In another embodiment, an apparatus is provided for selectively dispensing radio frequency identification (RFID) labels disposed on a first surface of a web carrier. The apparatus includes means for advancing the web carrier; means for programming each RFID label on the advancing web carrier; means for determining success or failure to program an RFID label; a peel bar positioned to contact the second surface of the advancing web carrier, the peel bar having a peel edge with a radius of a size that causes an RFID label to be separated from the first surface of the web carrier as the second surface of the web carrier contacts and travels at least partially around the edge; a cam bar positioned to contact the second surface of the advancing web carrier, wherein the cam bar moved to a first position causes the second surface of the web carrier to contact and travel at least partially around the edge of the peel bar, and the cam bar moved to a second position prevents the second surface of the web carrier from contacting and traveling at least partially around the edge of the peel bar, wherein an RFID label remains affixed to the web carrier when the cam bar is in the second position and the web carrier advances over the peel bar; means, responsive to a success in programming an RFID label, for moving the cam bar to the first position; means, responsive to a failure in programming an RFID label, for moving the cam bar to the second position; and means for winding the advancing web carrier following advancement past the cam bar. 
     The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and detailed description that follow more particularly exemplify these embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention may be more completely understood in consideration of the detailed description of various embodiments of the invention that follows in connection with the accompanying drawings, in which: 
         FIG. 1  is a perspective illustration of an RFID dispensing apparatus according to an embodiment of the invention; 
         FIG. 2  is a partial side view of components of the RFID dispensing apparatus with a cam bar in a reject position for preserving a rejected RFID label on a label web; 
         FIG. 3  is a partial side view of components of the RFID dispensing apparatus with the cam bar in an apply position for separating a programmed RFID label from the label web; 
         FIG. 4  is a perspective view of a carriage assembly having a peel bar and a cam bar mounted thereon; 
         FIG. 5  is a perspective view of the cam bar and linkage assembly for moving the bar between reject and apply positions; 
         FIG. 6  is a perspective view of a bottom assembly on which the pneumatic actuator of the cam bar ( FIG. 1 ) is mounted; 
         FIG. 7  is a block diagram of a control system for programming RFID labels, controlling advancement of the label web, and positioning the cam bar in the apply and reject positions according to the success or failure of programming an RFID label; 
         FIG. 8  is a flowchart of an example process for operation of the control system of  FIG. 7 ; 
         FIG. 9  is a flowchart that further describes the encode and verify mode of operation. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION 
     The present invention is believed to be useful for evaluating and dispensing RFID labels. While the present invention is not necessarily limited to such applications, various aspects of the invention may be appreciated through a discussion of various examples using this context. 
       FIG. 1  is a perspective illustration of an RFID dispensing apparatus  10  according to an embodiment of the invention. The apparatus includes a supply of RFID labels on roll  12 , which is secured on a spindle  14 . The roll  12  supplies a web  16  having a carrier surface  18  and RFID labels  20  that are secured thereto with a suitable, releasable adhesive. 
     The web  16  passes through a drive station  22  including a drive roller  24 , which is driven by a motor (not shown). In one embodiment, the motor is a stepper motor. However, other suitable motors, such as a servo motor, may be employed. The web is advanced beneath RFID programmer module  26 , and the programmer module programs the labels as they pass beneath the module. The web  16  is carried to a dispensing location  28 , at which peel bar  30  and cam bar  32  cooperatively separate labels from the web. A label tamper (not shown) mounts to bracket  34  and forces a label separated from the web onto an article below the tamper. The web  16  is fed through various idler rollers  36  to a take up spindle  46 . 
     Whether an RFID label is separated from the web  16  depends on the position of the cam bar  32 . In  FIG. 1 , cam bar  32  is in a reject position (see also  FIG. 2 ), which causes an advancing RFID label  38  to remain on the web  16 . When cam bar  32  is in an apply position (see  FIG. 3 , for example) an RFID label is separated from the web for application to an article. An RFID label separates from the web  16  as a result of the sharp angle introduced in the path of travel of the web by the peel bar  30 . A pneumatic tube  40  is positioned to provide a current of air to lift a label as it peels from the web  16  for application to an advancing article. The pneumatic tube is ventilated at positions suitable for causing a separated label to rise. 
     When the cam bar  32  is in the reject position, ( FIGS. 1 and 2 ) the path of the web  16  is extended beyond the peel bar  30 , which effectively destroys the peel angle (the angle at which an RFID label would detach from the web). The rejected RFID label  38  remains attached to the web  16 , and the rejected label  38  is carried by the web  16  to the take up wheel  46  as illustrated. 
     Label dispensing apparatus  10  is a modular system. A chassis  50  supports the RFID programmer module  26 , the tamper that mounts to bracket  34 , supply spindle  15  and take-up wheel  46 . In addition, carriage assembly  52  is mounted below the programmer module  26 , and bottom assembly  54  is mounted to the bottom of chassis  50 . 
     The carriage assembly  52  supports the peel bar  30  and the cam bar  32  (see also  FIG. 4 ). The peel bar is fixedly mounted on the carriage assembly  52 , and the cam bar is mounted on the carriage assembly in a manner that allows the bar to be rotated to the reject position (as shown in  FIG. 1 ) in response to a failure to program an RFID label, and to be rotated to an apply position (as shown in  FIG. 3 ) when programming of the RFID label is successful. 
     The bottom assembly  54  mounts to the bottom of chassis  50  and has mounted thereon idler rollers  36  and pneumatic tube assembly  56 . In addition, movement of the cam bar  32  is actuated with pneumatic linkage (not shown in  FIG. 1 ), and the pneumatic linkage is mounted on the bottom assembly  54 . In the example embodiment, the cam bar  32  is mounted on the carriage assembly  52 , but movement of the cam bar is actuated from structure on bottom assembly  54 . 
       FIG. 2  is a partial side view of components of the RFID dispensing apparatus with the cam bar  32  in a reject position for preserving a rejected RFID label on a label web. The view also illustrates the positions of the peel bar  30  and cam bar  32  relative to a tamper  72  and article  74  to which a label is to be applied. 
     Cam bar  32  is rotated about pivot point  76  and toward the article  74  when a label is rejected. The reject position of cam bar  32  extends the path of the web  16  such that the peel angle introduced by peel bar  30  is destroyed. The cam bar in the reject position causes the label  38  to remain affixed to the web  16  and recovered to take-up wheel  36 . By preserving the label on the web, the label may be returned to the manufacturer for fault analysis and application of a credit to the label customer. 
       FIG. 3  is a partial side view of components of the RFID dispensing apparatus with the cam bar  32  in an apply position for separating a programmed RFID label from the label web. Cam bar  32  is rotated about pivot point  76  and away from article  74  when a label is to be applied. The apply position of cam bar  32  changes the path of the web  16  such that the peel angle is introduced by peel bar  30 . The cam bar in the apply position causes the label  38  to separate from the web  16 . A current of air from air tube  40  (not shown in  FIG. 3  but shown in  FIG. 1 ) forces the label toward tamper for application to article  74 . 
       FIG. 4  is a perspective view of carriage assembly  52  having a peel bar  30  and a cam bar  32  mounted thereon. The peel bar  30  is fixedly mounted to the carriage assembly  52  on side members  82  and  84  of the assembly. Any suitable attachment mechanism may be used such that a peel angle may be introduced into the path of the web (not shown in  FIG. 4 ) traveling over the peel bar. Size, material, position, and other attributes of the peel bar may vary according to implementation requirements. Those skilled in the art will recognize other suitable alternative shapes for the peel bar. For example, instead of wedge shaped, the peel bar could be a round bar having a radius small enough to cause the separation of the RFID label from the web carrier when the web carrier travels partially around the bar. Also, those skilled in the art will recognize that even though the illustrated peel bar  30  is wedge shaped, the edge at some level of magnification is actually rounded with a small radius. The radius or sharpness of the edge may vary by application. 
     The cam bar  32  is also mounted to the carriage assembly on side members  82  and  84 . The mounting of the cam bar permits the cam bar to be rotated between reject and apply positions. In  FIG. 4 , the cam bar is in the apply position. In moving to the reject position, the bar rotates about an axis generally formed along shaft  86  in the direction indicated by arrow  88 . Any suitable attachment mechanism may be used for the cam bar such that the cam bar may be between apply and rejection positions. Size, material, position, and other attributes of the cam bar may vary according to implementation requirements. 
       FIG. 5  is a perspective view of the cam bar  32  and the linkage assembly  92  for moving the bar between reject and apply positions. The linkage assembly in the example embodiment includes push bar  94 , first linkage member  96 , and second linkage member  98 . Push bar  94  is coupled to a pneumatic control system ( FIG. 7 ). An increase in air pressure causes the push bar  94  to push the cam bar  32  in the direction of arrow  102 . A decrease in air pressure causes the push bar  94  to pull the cam bar  32  in the direction of arrow  104 . 
     The first linkage member  96  is fixedly mounted to push bar  94 . The second linkage member  98  is mounted to both the cam bar  32  and to the second linkage member  96  in a manner that permits the second linkage member to rotate at both mount points  106  and  108 . Size, material, position, and other attributes of the components of the linkage assembly  92  may vary according to implementation requirements. In another embodiment, the cam bar  32  may be moved between the reject and apply positions by electromechanical means. Furthermore, the push bar need not be connected to the cam bar and instead could engage the cam bar with surface-to-surface application of force. 
       FIG. 6  is a perspective view of a bottom assembly  54  on which the pneumatic actuator of the cam bar ( FIG. 1 ) is mounted. The pneumatic actuator includes pneumatic supply tube  112 , pressure chamber  114 , block  116 , along with the push bar  94 , first linkage member  96 , and second linkage member  98  as described above. In addition to the pneumatic actuator, the bottom assembly  54  includes air tube assembly  56  (without the pneumatic tube in order to not obstruct the diagram), idler rollers  36 , and the assembly for moving the idler rollers for adjusting tension in the web. 
     Air pressure from the pneumatic control system ( FIG. 7 ) is provided to the pneumatic actuator via pneumatic supply tube  112 . The supply tube  112  provides a flexible routing of pneumatic pressure and is connected to the pneumatic chamber  114 , which provides a stable reservoir for regulating pressure applied to the push bar  94 . 
     Block  116  is pneumatically coupled to pneumatic chamber  114 , and push bar  94  extends from and retracts into block  116  in a plunger-type action in the direction of arrow  120  in response to changes in pressure from the pneumatic supply tube  112 . 
       FIG. 7  is a block diagram of a control system  200  for programming RFID labels, controlling advancement of the label web, and positioning the cam bar in the apply and reject positions according to the success or failure of programming an RFID label. The control system  200  includes a processor  202  which has a plurality of inputs and outputs hereinafter as discussed. The processor  202  is programmable to perform various control functions. 
     A gap sensor (not shown) is positioned adjacent the web  16  in order to detect a trailing edge of each RFID label as it passes, and a gap sense signal is input to the processor  202  on line  204 . Input signals on lines  206  and  208  indicate to the processor whether the cam bar  32  is in the peel position or reject position, respectively. 
     A transponder unit  212  has an output antenna  214  for transmitting an activation signal  216  to the RFID label  218 . If operative, the RFID label is responsive to the activation signal  216  and produces an output or verification signal  220  for transmission to the antenna  214  and the transponder  212 . If the verification signal  220  produced by the RFID label  218  indicates successful programming, the transponder  212  produces an accept output A indicative of an acceptable RFID label. If the verification signal  220  indicates unsuccessful programming, the transponder  212  produces a reject output R. The accept output A and the reject output R are coupled for input to the processor  202 . 
     In response to an accept output A, the processor  202  produces a first control code  232  (or activation signal) for the pneumatic control system  234 , which causes the pneumatic control system to reduce pneumatic pressure in order to move the cam bar  32  to the apply position ( FIG. 3 ). In response to a reject signal R, the processor  202  produces a second control code  232  (or deactivation signal) which causes the pneumatic control system  234  to increase pneumatic pressure in order to move the cam bar  32  to the reject position ( FIG. 2 ). 
       FIG. 8  is a flowchart of an example process  300  for operation of the control system of  FIG. 7 . The present invention is operable in a variety of modes, including an electronic product code (EPC) Apply Only mode  302 ; an EPC Verify Mode  304 ; and an EPC Encode and Verify Mode  306 . In the Apply Only Mode  302 , the label is simply applied to the advancing article without checking the operability of the RFID label. In the Verify mode  304 , the RFID label is applied to the advancing article in accordance with the operability of the RFID, or it is rejected if inoperable. In the Encode and Verify mode  306 , the RFID label is first encoded with data specific to the product and is thereafter tested to verify operability before application to the advancing article. 
     An enable signal  310  initiates operation of the device. Mode selection occurs at  312 . For Verify Mode  304 , the verification sequence includes initiating a Read Tag operation at  314 , whereupon a signature is produced to activate the RFID. If the appropriate verification response is received, a Good Tag Present output is produced at  316 . The Good Tag Present output causes the drive to advance one label at high speed to the application location, whereupon the label peels from the web at block  318 . 
     In an example embodiment, the cam bar  32  defaults to the peel position. If the Read Tag signal  314  does not result in an appropriate response, the Bad Read block  320  produces an output which initiates a selected number of attempts at Retry block  322  to verify the operability of the tag. If after the selected number of attempts, a Bad Read signal persists, Retry  322  expires and Reject Tag Present is set at  324 . The drive moves the web forward at high speed through one label position at  326 . If the reject is indicated, the processor signals the pneumatic control system to apply pneumatic pressure and move the cam bar to the reject position, thereby causing the RFID to remain on the web  16 . 
       FIG. 9  is a flowchart that further describes the encode and verify mode of operation. The tag is read at Read Tag  328 . If a Good Read  330  output is produced, write EPC Data is initiated at block  332 . Thereafter, the tag is read again  334  to verify that the data written on the tag is correct. If the data is correct, a Good Tag present output is set block at  336  and the controller sees a Good Tag present signal. This signal advances the web at  338  by one label that reset the module. If verification does not result in a good signal, Read Tag Block  334  produces an output. After a number of retries at  340 , Retry Expires at  342 . The output of the Retry Expires  342  causes the processor to set Reject Tag present Block  344  and actuate the pneumatic control system to apply pneumatic pressure to move the cam bar to the reject position. The web is advanced by one label at block  346 . 
     If the initial Read Tag step at  328  results in a Bad Read and a selected number of retries are attempted at  348 , and the number of retries expires at  150 , the process sets the Reject Tag Present at block  344  and continues as described above. 
     While certain aspects of the present invention have been described with reference to several particular example embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Aspects of the invention are set forth in the following claims.