Abstract:
In combination, an RFID antenna array, an RFID tag reader, and a power supply, the foregoing components being adapted to be worn or otherwise borne by a person and be operatively connected so that the power supply powers the reader and the reader energizes the antenna array and receives RFID tag signals through the antenna array while the person passes through an area as the person&#39;s hands and arms are unencumbered by said components.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The invention relates to RFID implementation and, in particular, to portable RFID reader technology. 
       PRIOR ART 
       [0002]    RFID tags and readers are in use in various inventory control applications as well as in manufacturing, shipping, and other commercial activities. As the cost of RFID systems and RFID tags has reduced, this technology has become more commonplace. In retail stores, warehouses, and in the shipping industry, for example, hand-held readers are carried by employees to scan components, products, packages and other objects. Scanning can be done, as examples, to confirm inventory status or the accuracy of fulfilling a shipping order. Numerous other applications exist and will develop where portable scanners serve important functions. For the most part, present day portable RFID scanners are somewhat uni-directional and are intended to be manually pointed at the object to be identified. 
       SUMMARY OF THE INVENTION 
       [0003]    The invention provides a portable RFID scanning system that can be comfortably worn, if not unconsciously, by an individual. The disclosed scanning system allows an employee to work hands free and perform various traditional tasks while the scanning operation is conducted automatically without specific attention by the employee. The scanning system, according to the invention, can be embodied in a vest-like garment fitted with an antenna array preferably in the form of elongated, flexible, multi-directional RFID antennas. The antennas, ideally, are of a type that exhibit diversity of beam direction and polarity. The antenna array is able to detect RFID tags throughout a near zone proximate to the location of the vest garment wearer. The antenna array is cabled to a portable reader and power supply carried on the vest or otherwise borne by the vest wearer. The garment based reader system can readily record the presence of any tags without any conscious effort on the part of the garment wearer. The tag data seen by the reader can be stored for later downloading or can be wirelessly transmitted to a separate remote controller. 
         [0004]    The inventive smart garment, thus, has the ability to register the presence of tags anywhere in a near zone or space established by the location and/or path taken by the person wearing the smart garment. The wearer can circulate through a facility, performing tasks related or unrelated to tag reading and the smart garment can determine the presence of all tags existing anywhere in the space traversed by the wearer. In a retail application, a store clerk can reface the product shelves and respond to customers&#39; inquiries as he or she would normally. While the clerk accomplishes these necessary tasks, the smart garment can check inventory and proper product location with essentially no effort or attention expended to deploy the RFID system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a showing of a clerk wearing the smart garment of the invention in the form of a vest; 
           [0006]      FIG. 2  is a rear view of the clerk illustrating one arrangement of an antenna array, a reader and associated battery; 
           [0007]      FIG. 3  is a side view of the clerk diagrammatically illustrating the distribution of radiation from an antenna array of the RFID reader system associated with the smart garment; 
           [0008]      FIG. 4  is a view of a preferred antenna array depicted in a flat configuration; and 
           [0009]      FIG. 5  is a cross-sectional view of one of the antennas of the array received in an elongated padded fabric pouch. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0010]    The invention relates to a portable RFID system  10  that includes an antenna array  11 , a reader  12  and a battery power supply  13  laid out in the plane of the drawing for illustration purposes in  FIG. 4 . A person  14  depicted in  FIGS. 1-3  carries the system  10  to scan RFID tags each associated with an individual object, typically a product, a component, package, or the like. With the system  10  of the invention, the person  14  is free to circulate through a space where RFID tagged goods are situated such as, by way of example, a retail store, warehouse, factory, shipping depot, medical facility, or other space. 
         [0011]    A preferred antenna array  11  of the present invention can be similar to that disclosed in U.S. Pat. No. 8,058,998, the disclosure of which is incorporated herein by reference. The present antenna array for radiating or receiving electromagnetic signals, unlike that disclosed in this patent, comprises highly flexible elongated antennas  16  that can be readily folded out of a single plane and are of limited length. 
         [0012]    Referring again to  FIG. 4 , the antenna array  11  preferably comprises two serpentine antennas  16 . Each antenna  16 , while lying on a flat support, has an elongated axis indicated by the broken line  17  across which a pair of parallel curvilinear feed lines  18  pass back and forth. The antennas  16  may be constructed of a rectangular, flexible, dielectric base sheet or film  19  such as Mylar® on which the feed lines  18 , made of an electrically conductive material such as a copper or an aluminum foil, are adhesively attached or otherwise fixed. At spaced locations, the feed lines  18  have perturbations in the form of relatively short stubs  21 . The stubs or dipole radiators  21  which are designed to radiate RF energy are typically made of the same material as the feed lines and are electrically connected to a respective feed line. Adjacent pairs of the stubs  21 , one on each feed line  18 , form dipoles. Preferably, each stub  21  extends at a right angle to the local part of the feed line  18  to which it is joined. 
         [0013]    An antenna  16  measured along its axis  17  is about 3 ft. long and the base sheet  19  supporting the stubs  21  is about 7 in. wide. Each antenna  16  is encased in a high durability water-resistant elongated flat fabric pouch  22 . A soft cushion layer of batting  23  is placed in the pouch  22  on the side of the antenna  16  which is to face the person  14  that will carry the antenna array  11 . A coaxial cable  24 , with its center conductor and its outer conductive sheath each connected to one of the feed lines  18  of the associated antenna  16  projects out of a pouch  22 . 
         [0014]    An effective way of deploying the antenna array  11  is to attach the individual antennas  16  to the inside of a vest  26  or similar garment. Preferably, the antennas  16  are positioned in the garment  26  so that one is on the left and one is on the right and the major length of each is at the front of the garment. The cables  24  are disposed on the inside back of the garment  26  and the radiators or stubs  21  proximate to a cable of each antenna are adjacent a shoulder of the garment  26 . 
         [0015]    The pouches  22  are preferably releasably held in place on the interior of the garment  26  by a suitable technique such as with Velcro®, snaps, buttons, zippers, pockets or other suitable fasteners. The releasable fasteners enable the pouch to be removed from the garment  26  so that the garment can be laundered or even replaced. 
         [0016]    The RFID reader  12  is connected to the antennas  16  through the respective cables  24 . The reader  12  and power supply  13 , typically a rechargeable battery electrically connected to the reader, are carried by the person  14  wearing the garment  26 . The reader  12  and power supply  13  can be located in an inner pocket on the garment  26 , secured by fasteners to the garment, or mounted on a waist belt separate from the garment. 
         [0017]      FIGS. 1-3  illustrate a preferred arrangement of the antenna array  11  being worn by the person or individual  14 .  FIG. 3  is a diagrammatic representation of the RF beams produced by the individual dipole radiators  21 . It will be understood that the antenna array  11  radiates into a near space in front of and to the sides of the person  14  wearing it in a pattern that is generally columnar, extending from floor level to a level overhead of the person  14 . Depending on the selected power level, the range of the antenna array  11  can be between 2 and 10 ft. 
         [0018]    RF power density that reaches the user is minimal. The power is distributed across all of the antenna stubs  21 . Antennas are preferably alternately powered, thus cutting the duty cycle in half. Further, the antennas  16  are not operated when the reader  12  is processing data further reducing the duty cycle of the antennas. The reader  12  energizes the antenna dipoles  21  and receives RFID signals from RFID tags through the antenna dipoles. Where desired, the person  14  wearing the garment  26  can be shielded from antenna radiation by providing a reflective material, for example, in the form of a conductive metal film or cloth next to the person. The spacing of this reflective material, which can be provided, for example, by the batting  23 , should be at least ¾ in. from the dipoles  21 . 
         [0019]    Due to the flexibility of the pouch  22  including its contents and the low weight owing to its cloth/film construction, a person  14  wearing the garment  26  is neither significantly burdened nor restricted in his or her movement by the system  10 . In particular, the person&#39;s hands and arms are completely free to accomplish any required task while wearing the garment mounted system. It will be understood that a person wearing the system can walk or otherwise traverse a space in which RFID tagged items are situated. The system  10  will read all of the tags within range of the antenna array  11 . The reader  12  can either temporarily store the data on a device that can later transfer it to a controller or can wirelessly transmit the data to a remote controller. 
         [0020]    While the invention has been described as being mounted on a vest-style garment, other arrangements are envisioned. Where a lab coat or gown is used as the garment  26 , the length of the antenna can be increased. It is also possible to arrange the antenna array in a stole or scarf garment. The “smart” garment based system, besides use in retail settings, can be used in other applications such as a factory assembly line, shipping department, and healthcare facilities. The system can verify assembly or shipping accuracy, among other applications, as well as inventory. In each application, the person wearing the system  10  is completely hands free and able to perform traditional or new manual tasks requiring unrestrained hand and/or arm movement. 
         [0021]    Specific areas of known location at a facility such as a store, factory, warehouse, or like premises can be permanently provided with a RFID tag. The location or near location of an RFID tagged item can be determined and/or recorded when the system  10  simultaneously detects the item tag and a location tag. No special attention on the part of the person  14  is necessary to locate an item. Where the system  10  communicates wirelessly with a remote controller on a real-time basis, the controller can send directions to the person. For example, if the person is searching the premises for a particular item, the controller can indicate, by radio, audio or visual signal, to the person that he or she is in the immediate vicinity of the item. The person  14  wearing the garment  26  and/or the garment itself can be provided with a RFID tag for purposes of monitoring work activity of the person, especially where location indicating RFID tags are strategically situated on the premises. 
         [0022]    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.