Abstract:
A system and method for monitoring shelf inventory that combines bar code and RFID technologies to permit electronic data entry of item shelf assignments and real time reporting of item removal from display/dispensing storage shelves.

Description:
[0001]    This application is a division of Ser. No. 13/222,079, filed Aug. 31, 2011. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to a system for integrating bar code and RFID tag technologies in retail dispenser shelving to provide real-time shelf inventory status. 
       PRIOR ART 
       [0003]    Currently, retailers routinely assign employees to walk through the aisles of a store to check for shelf items that are depleted or nearly depleted. On the basis of what is seen by the clerk, replacement items can be drawn from the “backroom” or warehouse. It would be beneficial to avoid the use of employees&#39; time in these shelf inventory surveys. 
         [0004]    Certain products being removed from a retail shelf by a customer may be complemented with other products, services, or advice that could be provided by the store management. Therefore, it would be advantageous to advertise or announce such complementary products or services to a customer with a video or audio presentation starting at the time an item is drawn from a shelf. 
         [0005]    Certain consumer items such as baby formula, medications and cosmetics, are targeted by organized crime. Criminals steal products by removing them from shelves and exiting a store by some subterfuge without paying for the stolen items. This activity is often characterized by a thief quickly taking all or most of a targeted item from a shelf. It would be therefore desirable for a retailer to have the ability to immediately detect a circumstance and location where an unusual number of items are removed from a shelf at the same time. Data on the time and frequency that items are removed from a shelf can be helpful in uncovering patterns and sources of “shrinkage” where there is no apparent explanation for a loss of inventory. 
         [0006]    RFID tag and reader technology has been extensively developed, but has yet to be widely implemented in retail operations because of costs. Such costs include not only the RFID tags, but also, labor and equipment to attach the tags as well as the associated hardware and software necessary for implementation of this technology. Some metal objects and liquids cannot easily or effectively use RFID tags. It would be desirable to derive some of the potential benefits of RFID technology in retail applications by applying this technology on a limited basis that can avoid otherwise currently prohibitive costs. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention is embodied in retail shelf systems that combine bar code and RFID technologies to achieve an adaptable, low cost, real time monitoring of shelf inventory. In various embodiments of the invention, a retail display and dispensing shelf has, from front to back, rows of RFID tags (hereafter “tags” or “tag” when singular, each tag with a unique identity and a unique bar code spatially associated with each row of tags. The system further includes an antenna arrangement, preferably multiple special twin-feed antennas, associated with the shelf and connected to a tag reader. The reader interfaces with a controller, inter alia, to store the identity of each tag row by a unique bar code, the location of the row on a shelf, the location of the shelf in the store, the identity of each of the tags associated with the row, and, if desired, their respective location in a row. On each shelf, the tags are preferably arranged in patterns corresponding to the patterns that retail items are arranged on a shelf. 
         [0008]    A portable bar code reader or scanner is used to electronically collect and feed data to the computer or controller. One effective way of implementing the invention is to correlate individual unique shelf bar codes, each embodied in a printed label, for instance, with a set of tags, each of unique identity. 
         [0009]    The tags can be fixed to a composite planar board that includes an electrically conductive ground plane spaced below the tags. The composite board can be disposed on a conventional shelving unit. The system relies on a medium that blocks communication between a tag and an antenna associated with the respective shelf when an item is resting on the shelf and overlies a tag. The medium can be the item itself, or some other barrier to radio waves that is displaced when the item is removed. 
         [0010]    The tags may be, but not necessarily, located in a pattern that corresponds, one for one, with the layout of items on a shelf. Ordinarily, all of the items being displayed on a shelf in a row or other pattern at a site associated with a common shelf bar code will be identical. 
         [0011]    The system can include any number of shelves and any number of bar code sites on any particular shelf. When an item is removed, an underlying tag is no longer blocked from communicating with a shelf antenna. A signal from an unblocked tag is received by an antenna and relayed to the reader of the system. The controller registers the signal as an item removed from the shelf within a very short time of the actual removal. The controller can initiate video and/or audio announcements while the customer is still at the area of the shelf. The controller can produce a signal requesting a re-stock of the shelf when all or most of the items are removed from a bar code site. If many of the items are removed en masse, the controller can signal a potential theft attempt. 
         [0012]    A significant advantage of the system comes from the integration of bar code and RFID technologies. As suggested, this integration enables the identity of an item on a shelf and the shelf row to which it is assigned to be electronically recorded by scanning the item UPC and the bar code of the row to which it is assigned with the hand-held bar code scanner. This feature is of significant advantage to those retailers who routinely shift the position of merchandise within a store from one shelf to another. The location of items reorganized among different shelves can be quickly and efficiently electronically entered and recorded simply with a portable hand-held bar code reader. The reader scans and records the bar code at the site of a row on a shelf and the UPC or bar code on an item to be placed on a shelf at such site. This data is transmitted to the system controller electronically so that human labor is minimized and data errors are reduced. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a front view of a retail shelf unit embodying the invention; 
           [0014]      FIG. 2  is a fragmentary diagrammatic exploded view of a shelf component of the invention; 
           [0015]      FIG. 3  is a fragmentary side perspective view of the shelf unit of  FIG. 1 ; 
           [0016]      FIG. 4  is a diagrammatic perspective view of a row or tray of a modified form of a shelf; and 
           [0017]      FIG. 5  is a schematic view of a shelf system illustrating, inter alia, a RFID tag reader, a hand-held bar code reader, and a controller. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]      FIG. 1  illustrates a shelf unit  10  typical of those found in retail stores or similar establishments that display goods to store customers. The unit  10  dispenses retail items in the sense that a customer can select a product and remove it from a shelf. The shelf unit  10  has several shelves  11  vertically spaced from one another. The shelves  11  customarily are arranged in horizontal planes, and are typically substantially longer than their front to rear (depth) dimension. A vertical back panel  12  prevents items from falling off the rear edge of the shelves. Various products or items  14  can be displayed on the same or different shelves  11 . As is conventional, identical items are arranged in rows  16  extending between a front  17  to a back  18  of a shelf  11 . In the illustrated case, a set of elongated twin feed, flat plane antennas  21  are vertically arranged in a vertical plane immediately behind the back panel  12 . The antennas  21  may be of the type known from U.S. Patent Publication No. US-2010-0060457-A1, the disclosure of which is incorporated herein by reference. The back panel  12  is made of a material that is transparent to radio waves. While the antennas  21  may each be identically constructed, they are preferably arranged so that some are inverted relative to others, some are flipped face-to-face from others, and some are higher than others so as to increase the diversity of the orientation of electromagnetic waves generated by the antennas. This diversity includes polarization and spatial diversities. 
         [0019]      FIG. 2  reveals one example of a panel assembly  41  with tags  42  for electronically maintaining real-time inventory of items on the shelves  11  of the unit  10 . The panel assembly  41  is a generally flat composite of individual layers including a bottom skin  43 , an electrically conducting ground plane  44 , a low density plastic foam core  45  and a top skin  46 . The bottom and top skins  43 ,  46  can be any suitable plastic film such as a polyolefin, ABS or vinyl; the top sheet or skin  46 , at least, is of suitable durability to resist damage or premature wear when items, including tin cans, for example, are placed on or removed from the panel assembly  41  without care. Both the top sheet or skin  46  and foam core  45  are substantially or completely transparent to radio waves. The core  45  is preferably an open or closed cell foam of a common thermoplastic or thermoset material and has a thickness of at least about ¾″ to space the tags  42  from the ground plane  44 . The layers  43 - 46  are held together at their respective interfaces by suitable adhesives, by welding, by mechanical fasteners or by other expedient. The tags  42  can be secured to either the foam core  45  or the top skin  46  or both. The panel assembly  41  is dimensioned so that its length and width are suitably received on a shelf  11  or its length can be an even fraction of the length of the shelf on which it will be placed so that a plurality of panel assemblies can be used to cover a shelf. 
         [0020]    The tags  42 , which are commercially available, are RFID tags that have a rectangular footprint and are essentially flat. The tags  42  are preferably arranged to correspond to a row  16  in which items are placed on the shelves  11  as described above. Ideally, but not necessarily, the spacing between adjacent tags  42  of a row  16  corresponds to the front to back spacing of items being retailed on the relevant row of a shelf  11 . Preferably, but again not necessarily, the spacing between tag rows is the same as the spacing between rows of retail items on a shelf  11 . Each tag  42  on any panel assembly  41  used in a retail store installation has a unique identity. In accordance with the invention, each row  16  of tags  42  has associated with it a bar code  51  located on the front of the panel assembly  41  in line with a respective row. The bar code  51  can be printed on a pressure sensitive label applied to the edge of the panel assembly  41  so that it is in a position to be optically scanned. 
         [0021]    From the foregoing, it will be understood that the full area of each shelf  11  of the unit  10  shown in  FIG. 1  will be covered by a panel assembly  41  like or similar to that illustrated in  FIG. 2 . If desired, panel assemblies  41  can be constructed of sufficient strength to form the shelves themselves. On the other hand, where the shelves  11  are metal sheets without major holes, the ground plane  44 , and the bottom skin  43 , can be omitted. The retail items located on the shelves  11 , by virtue of their dense dielectric properties, or being in a metal container, or having a metal foil blank attached to their bottom, block radio wave energy and thereby mask the tags  42 . The electrically conducting ground plane  44 , likewise, blocks this energy. Electromagnetic waves travelling parallel or nearly parallel to the plane of the panel assembly  41 , i.e. through the plane of the foam core  45  and, therefore, parallel to the plane of the tags  41  are not effective in exciting the tags. Therefore tags  42  receiving energy only in this direction will not be seen by the shelf antennas  21 . 
         [0022]    Retail items opaque to radio waves and properly located on a shelf will overlie and electromagnetically shield underlying tags  42  so that these tags cannot be seen by the shelf antennas  21 . Contrarily, when a retail item is removed from a shelf, the tag  42  beneath it is exposed to electromagnetic energy and will be immediately seen by the shelf antennas  21 . 
         [0023]      FIG. 5  diagrammatically illustrates additional parts of the shelf system that achieves adaptable “real-time” inventory status. The shelf antennas  21  communicate with a reader unit  56 , known in the art, that identifies any tags  42  illuminated by the antennas. The reader unit  56 , in turn, communicates with a computer-based controller  57  which is programmed to monitor and report changes in shelf inventory. While shown as separate components, the reader  56  and controller  57  can be integrated. The shelf inventory information, garnered by the controller  57 , can regularly be used to initiate shelf re-stocking and reordering of product. The disclosed system has the significant benefit of monitoring the shelf inventory on a real-time basis, being responsive typically within seconds to a change in the number of tags being seen by the shelf antennas  21 . 
         [0024]    Under normal conditions, in addition to signaling a need to replenish the shelf with certain items, the controller  57  can record data reflecting the time and date of item removal. The controller  57  can be programmed to issue a lost item report when an item has been removed from a shelf but has not appeared at a cash register within a prescribed time. In other special circumstances, the system can respond in other ways. For example, experience has shown organized crime thieves target certain retail products that can be easily hidden and easily sold. To be profitable for the perpetrators, these thefts are characterized by quickly grabbing all or most of the same item from a shelf. The controller  57  can be programmed to respond to a sudden reduction of identical shelved items by instantly sending an alarm to appropriate personnel. The alarm signal can include identity of the precise location in a store where the activity is occurring. The controller can, for example, focus a security camera at the identified location in the store to record the activity and pictures of suspected culprits. 
         [0025]    The employee  59  stocking shelves can be issued an identification badge that can be electronically recognized by the shelf system controller  57 . For example, the badge can have an RFID tag associated with it that can be seen by the shelf antennas  21 . Alternatively, the employee badge can have an associated bar code capable of being read and electronically reported by the portable bar code scanner  61  being used by the employee when stocking shelves. With the controller  57  aware of the identity of the person stocking a shelf at the time of this activity his productivity can be observed and accurately measured. If desired, the controller  57  can be programmed to cause the restocking labor to be video monitored. The metrics recorded by the controller can include the number of items actually being placed on a shelf and the time expended since the shelf antennas  21  report changes in shelf inventory on a real time basis. The identity of the person stocking the shelf, his promptness and his efficiency can be recorded and made available to the manufacturer of an item being stacked to assure that the manufacturer&#39;s item is displayed according to the terms existing between the retailer and the manufacturer. 
         [0026]    The system, through the antennas  21  and reader  56  can detect a customer carrying a loyalty card with an embedded RFID tag identifying the customer. This feature can be used for marketing purposes based on the customer withdrawing a particular item from a shelf. 
         [0027]    The system can readily monitor compliance with a “planogram” by which store management dictates the location of all shelves and items to be shelved. Assuming each shelf is initially properly laid out according to an authorized floor plan and each shelf and its associated tags are registered in the controller memory, the controller can be programmed to verify that the items being placed on each shelf row (with a representative item first scanned for its UPC code) as the items specified by the planogram. 
         [0028]    An important aspect of the invention is the ability to electronically enter and record the selected location for each kind of item to be placed on a shelf  11  in a retail store or other establishment. Moreover, the system enables the location at which items are to be shelved to be changed whenever necessary or desired and allows such a change to be entered and recorded electronically. Such changes will routinely occur when new products are introduced by a supplier and/or when the store management chooses to rearrange the product display for merchandising purposes or when existing products are discontinued either by the retailer or by the supplier. 
         [0029]    Ordinarily, the bar code  51  (which is a unique number) at each shelf row  16  will have a unique set of tags  42  associated with it and this correspondence will be stored in the memory of the controller  57 . The invention allows a clerk or other personnel member pictured in  FIG. 5  at  59  to use a portable bar code scanner  61  to electronically read a shelf row bar code  51  and the UPC bar code of an item that the retailer has selected to be currently displayed at the row  16  of a particular shelf  11 . The ability to electronically correlate the identity of a shelf row  16  and the item or product on the shelf  11  and to transmit this correlation to the controller  57  greatly improves productivity and reduces errors in collecting, transmitting and entering this data. To illustrate a typical shelf and tag layout in  FIG. 5 , no salable items are shown but, normally, the tags will be covered with salable items organized in rows aligned with bar codes  51 . The bar code reader or scanner  61  electronically relays scanned information, through RF or hardwire communication to the controller  57 . The controller  57  having this data in memory as well as the capacity of the row  16  will immediately know the shelf inventory of the relevant row based on the number of tags that are electromagnetically blocked on that row. 
         [0030]      FIG. 4  illustrates a variant of a retail shelf arrangement. A shelf dispenser unit  66  incorporates a spring actuated pusher plate  67  known in the art. The shelf dispenser unit  66  includes an electrically conductive strip in the form of a flat spring steel ribbon  68  coiled on itself. One end of the spring  68  is anchored to a front end of the unit  66  and the main body of the spring coil is journalled on an axis behind the pusher plate  67 . The spring  68  exerts a generally constant forward force on the pusher plate  67  as well as any items placed in the row  16  ahead of the plate. The plate  67  is guided for movement between the front and back of the unit  66  on slides or tracks  69  running along the row  16 . The unit  66  is loaded with retail items by manually pushing the plate  67  into the rear of the row and positioning items in front of it. A small barrier (not shown), is provided at the forward end of the unit  66  to restrain items and resist the force of the spring. The forwardmost item can be dispensed from the unit  66  by lifting it above the barrier. 
         [0031]    For simplicity, only one shelf dispenser  66  is shown in  FIG. 4 , but it will be understood that a typical shelf will have several side-by-side parallel identically constructed units. As with the previously described shelf unit  10 , each shelf dispenser  66  has a unique bar code  51  and a set of unique tags  42 . The tags are evenly spaced along a row  16  of the shelf dispenser  66  beneath the path of the steel spring  68 . The tags  42  can be provided on a composite panel like the panel assembly  41  described in connection with  FIG. 2 . The bar code  51  is registered with each of its associated tags  42 , situated along the respective shelf dispenser  16 , in the memory of the system controller  57 . The spring  68  blocks radio wave communication between the shelf antennas  21  and the tags  42  it covers, i.e. the tags in front of the pusher plate  67  but not behind it. Thus, the tags  42  are masked by any overlying portion of the spring  68 . The spring driven pusher plate style shelf dispenser is particularly useful with items that do not inherently block radio waves. 
         [0032]    Multiple shelf dispenser units  66  can be used in place of a panel  41  in the unit  10  described above in connection with  FIGS. 1 and 3  and in the processes described in connection with the system of  FIG. 5 . 
         [0033]    In some applications where the retail item is small, the spring  68  driving a pusher plate  67  may be relatively narrow. In such a case, the tags  42  can be aligned with the lengthwise direction of a shelf row  16  or otherwise oriented to ensure that the tags are adequately blocked when the spring overlies them. In such as case, resolution of the system is reduced such that removal of more than one item may be needed to register a change in the tags being read. 
         [0034]    The shelf row  16  or shelf dispenser  66  can be identified by other than the optically scannable bar code  51 . For example, these row or dispenser sites can be individually identified by an associated RFID tag, a magnetic code, optical characters or patterns, or other indicia that can be electronically read by a portable scanner and electronically coupled by wire or wireless to the reader (in the case of an RFID row or dispenser tag) or the controller  57 . 
         [0035]    It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited.