Patent Publication Number: US-2020287270-A1

Title: Edge on foam tags

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
     The present application is a division of U.S. utility patent application Ser. No. 14/565,726 filed Dec. 10, 2014 which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to a radio-frequency identification (RFID) antenna that is designed to operate in proximity to metal surfaces. Specifically, the antenna is positioned at 90 degrees to the surface, allowing the antenna to operate with minimal separation from the edge of the RFID antenna to the metallic object. The present subject matter is especially suitable for food and medication containers. In accordance with embodiments of the present subject matter, an RFID antenna is provided that is designed to operate in proximity to conductive surfaces, with the surfaces including high dielectric constant and high dielectric loss, such as some liquids, gels, solutions, and combinations of these surfaces and material. Particular relevance is found in connection with sealed food and medication containers. Accordingly, the present specification makes specific reference thereto. However, it is to be appreciated that aspects of the present inventive subject matter are also equally amenable to other like applications. 
     Radio-frequency identification (“RFID”) is the use of electromagnetic energy (“EM energy”) to stimulate a responsive device (known as an RFID “tag” or transponder) to identify itself and in some cases, provide additionally stored data. RFID tags typically include a semiconductor device commonly called the “chip” on which are formed a memory and operating circuitry, which is connected to an antenna. Typically, RFID tags act as transponders, providing information stored in the chip memory in response to a radio frequency (“RF”) interrogation signal received from a reader, also referred to as an interrogator. In the case of passive RFID devices, the energy of the interrogation signal also provides the necessary energy to operate the RFID device. 
     RFID tags may be incorporated into or attached to articles to be tracked. In some cases, the tag may be attached to the outside of an article with adhesive, tape, or other means and in other cases, the tag may be inserted within the article, such as being included in the packaging, located within the container of the article, or sewn into a garment. The RFID tags are manufactured with a unique identification number which is typically a simple serial number of a few bytes with a check digit attached. This identification number is incorporated into the tag during manufacture. The user typically cannot alter this serial/identification number and manufacturers guarantee that each serial number is used only once. This configuration represents the low cost end of the technology in that the RFID tag is read-only and it responds to an interrogation signal only with its identification number. Typically, the tag continuously responds with its identification number. Data transmission to the tag is not possible. These tags are very low cost and are produced in enormous quantities. Such read-only RFID tags typically are permanently attached to an article to be tracked and, once attached, the serial number of the tag is associated with its host article in a computer data base. The RFID tag data, both a unique ID and data stored in a read/write memory, may also be associated in a database with a host article, but not always. The tag may store data read from a bar code, or the item identification, its manufacturing date etc. and have no association with a database or requirement to access one. 
     Read only tags, those that respond with a pre-programmed code when powered up at a regular or pseudo random interval, are no longer commonly used. 
     Most tags now incorporate chips that include both read only memory, that usually contains configuration bits, manufacturers ID, chip model number and a unique ID ranging between 2 and 9 bytes in length, and read write memory commonly between 12 and 16 bytes, although larger memories may be used. The unique ID is used in combination with the manufacturers ID and chip model number (two different chip manufacturers could use the same unique ID). 
     Specifically, an object of the tag is to associate it with an article throughout the article&#39;s life (the tag may be applied at any point in the supply chain, not necessarily for the articles life) in a particular facility, such as a manufacturing facility, a transport vehicle, a health care facility, a pharmacy storage area, or other environment, so that the article may be located, identified, and tracked, as it is moved. Tracking the articles through the facility can assist in generating more efficient dispensing and inventory control systems as well as improving work flow in a facility. This results in better inventory control and lowered costs. In the case of medical supplies and devices, it is desirable to develop accurate tracking, inventory control systems, and dispensing systems so that RFID tagged devices and articles may be located quickly should the need arise, and may be identified for other purposes, such as expiration dates or recalls. 
     Many RFID tags used today are passive in that they do not have a battery or other autonomous power supply and instead, must rely on the interrogating energy provided by an RFID reader to provide power to activate the tag. Passive RFID tags require an electromagnetic field of energy of a certain frequency range and certain minimum intensity in order to achieve activation of the tag and transmission of its stored data. Another choice is an active RFID tag; however, such tags require an accompanying battery to provide power to activate the tag, thus increasing the expense and the size of the tag and making them undesirable for use in a large number of applications. 
     Depending on the requirements of the RFID tag application, such as the physical size of the articles to be identified, their location, and the ability to reach them easily, tags may need to be read from a short distance or a long distance by an RFID reader. Furthermore, the read range (i.e., the range of the interrogation and/or response signals) of RFID tags is also limited. 
     Furthermore, when the RFID tags are attached to a conductive surface, an RFID tag may have difficulties in being read. In those situations where reading a tag is problematic, such as where the space between a dipole and its image is small reducing the space creates difficulty in reading the tag, such as where the space is very small (less than one wavelength), then the total effective current between the dipole and its image is equal to zero or near zero. As the spacing between the antenna and the metal plane decreases the efficiency of the antenna reduces and it becomes difficult to achieve an impedance match to a device such as an RFID chip over a useful bandwidth. The issues become more apparent when the spacing is ˜&lt;1% of one wavelength; these problems can be mitigated to some extent by using a separator between the antenna and plane. For example, a high dielectric constant material may be used, or a material with both a high dielectric constant and high relative permeability, to increase the effective separation. However, such materials are expensive, and not suitable for RFID tags, where lower cost materials, such as papers/card, simple plastics such as PET and polypropylene foams are more desirable; all of these have relatively low dielectric constants. 
     Thus, the total radiated field is negligible and therefore, the RFID tag is unable to capture data and power from the reader. This is a significant problem given that in many commercial applications it is desirable to apply the RFID tag to a metal or other type of conductive surface. What is needed therefore is an RFID tag device and/or system that allows the RFID tag to operate in proximity to metal surfaces or other types of conductive surfaces. 
     The present invention discloses an RFID antenna structure that is designed to operate in proximity to metal surfaces. The RFID antenna structure is placed at 90 degrees to the surface of the metallic object, allowing it to operate with minimal separation from the edge of the RFID antenna structure to the metallic object. 
     SUMMARY 
     The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed innovation. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later. 
     The subject matter disclosed and claimed herein, in one aspect thereof, comprises an RFID antenna structure that is designed to operate in proximity to metal surfaces. The RFID antenna structure is placed at 90 degrees to the surface of the metallic object, allowing it to operate with minimal separation from the edge of the RFID antenna structure to the metallic object. 
     In a preferred embodiment, the RFID antenna structures may be thin and formed into a number of shapes depending on the form factor used. Specifically, the RFID antenna structure can be linear and incorporated into a protective plastic layer by extrusion, wrapped in a number of shapes, wrapped around a form and placed in a cavity, or incorporated into a structure by injection molding. In another embodiment, the container comprises an anti-tamper (or tamper evident) embodiment wherein the RFID tag device is applied to twist and flip-top cap containers, wherein tearing along the perforations on the cap disables the RFID tag device. 
     To the accomplishment of the foregoing and related ends, certain illustrative aspects of the disclosed innovation are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles disclosed herein can be employed and is intended to include all such aspects and their equivalents. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These, as well as other objects and advantages of this invention, will be more completely understood and appreciated by referring to the following more detailed description of the presently preferred exemplary embodiments of the invention in conjunction with the accompanying drawings, of which: 
         FIG. 1  illustrates a top perspective view of the RFID antenna structure in accordance with the disclosed architecture; 
         FIG. 2  illustrates a top perspective view of the RFID antenna structure on a metallic object in accordance with the disclosed architecture; 
         FIG. 3  illustrates a graph of the RFID antenna performance on both a metal surface and a non-metal surface in accordance with the disclosed architecture; 
         FIG. 4  illustrates a top perspective view of the RFID antenna structure within a lid of a container in accordance with the disclosed architecture; 
         FIG. 5  illustrates a top perspective view of the RFID antenna structure within a larger lid of a container in accordance with the disclosed architecture; 
         FIG. 6  illustrates a graph of the RFID antenna performance edge on to a foil sealing disk in accordance with the disclosed architecture; 
         FIG. 7A  illustrates a top perspective view of the RFID antenna structure made by flat roll to roll lamination in accordance with the disclosed architecture; 
         FIG. 7B  illustrates a side perspective view of the RFID antenna structure in accordance with the disclosed architecture; 
         FIG. 8  illustrates a top perspective view of the RFID antenna structure wrapped around a shape in accordance with the disclosed architecture; 
         FIG. 9  illustrates a top perspective view of the RFID antenna structure extruded inside a plastic strip in accordance with the disclosed architecture; 
         FIG. 10  illustrates a front perspective view of the RFID antenna structure wound helically around a narrower former in accordance with the disclosed architecture; 
         FIG. 11  illustrates a front perspective view of the RFID antenna structure formed into a flat spiral in accordance with the disclosed architecture; 
         FIG. 12A  illustrates a front perspective of the RFID antenna structure attached to a metal surface in accordance with the disclosed architecture; 
         FIG. 12B  illustrates a front perspective of another embodiment of the RFID antenna structure attached to a metal surface in accordance with the disclosed architecture; 
         FIG. 13A  illustrates a front view of a label positioned on a twist cap container with the RFID inlay over the container in accordance with the disclosed architecture; 
         FIG. 13B  illustrates a front view of the label and inlay being torn along the perforations in accordance with the disclosed architecture; 
         FIG. 13C  illustrates a front view of the label with reduced adhesion in accordance with the disclosed architecture; 
         FIG. 14A  illustrates a front view of a label positioned on a flip-top cap container with the RFID inlay over both the cap and the container in accordance with the disclosed architecture; 
         FIG. 14B  illustrates a front view of the label and inlay being torn along the perforations in accordance with the disclosed architecture; 
         FIG. 15A  illustrates a front view of a label positioned on a flip-top cap container with the RFID inlay over the container in accordance with the disclosed architecture; 
         FIG. 15B  illustrates a front view of the label and inlay being torn along the perforations in accordance with the disclosed architecture; and 
         FIG. 15C  illustrates a front view of the label with reduced adhesion in accordance with the disclosed architecture. 
     
    
    
     DETAILED DESCRIPTION 
     The innovation is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. It may be evident, however, that the innovation can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate a description thereof. 
     The present invention discloses an RFID antenna structure that is designed to operate in proximity to metal surfaces. The RFID antenna structure is placed at 90 degrees to the surface of the metallic object, allowing it to operate with minimal separation from the edge of the RFID antenna structure to the metallic object. Furthermore, the RFID antenna structures may be thin and formed into a number of shapes depending on the form factor used. Specifically, the RFID antenna structure can be linear and incorporated into a protective plastic layer by extrusion, wrapped in a number of shapes, wrapped around a form and placed in a cavity, or incorporated into a structure by injection molding. 
     Referring initially to the drawings,  FIG. 1  illustrates the RFID antenna structure  100  that is designed to operate in proximity to metal surfaces. The RFID antenna structure  100  is placed at 90 degrees (or any other suitable distance) to the surface of the metallic object, allowing it to operate with minimal separation from the edge  102  of the RFID antenna structure  100  to the metallic object. The RFID antenna structure  100  can comprise any suitable antenna as is known in the art, such as, but not limited to, a dipole antenna. Specifically, the RFID antenna structure  100  is formed from an RFID inlay that can be adhered to a material such as paper, plastic, or foam, such as, but not limited to, an Avery Dennison 160u7 inlay. The RFID inlay comprises an RFID chip and aluminum, copper or silver antenna bonded to a polyethylene terephthalate (PET) layer or other suitable layer as is known in the art. The RFID inlay can then be adhered to the back side of a label or other suitable material and printed and encoded in an RFID printer. 
     The RFID antenna structure  100  can be any suitable size, shape, and configuration as is known in the art without affecting the overall concept of the invention. One of ordinary skill in the art will appreciate that the shape and size of the antenna structure  100  as shown in  FIG. 1  is for illustrative purposes only and many other shapes and sizes of the antenna structure  100  are well within the scope of the present disclosure. Although dimensions of the antenna structure  100  (i.e., length, width, and height) are important design parameters for good performance, the antenna structure  100  may be any shape or size that ensures optimal performance and sensitivity during use. 
     As illustrated in  FIG. 2 , the RFID antenna structure  100  is shown on a metallic object  200 . The RFID antenna structure  100  is placed at 90 degrees to the surface of the metallic object  200 , allowing it to operate with minimal separation from the edge  202  of the RFID antenna structure  100  to the metallic object  200 . With reference now to  FIG. 3 , there is illustrated a graph of the performance of the RFID antenna structure on both a metal surface and a non-metal surface. 
     With reference now to  FIG. 4 , there is illustrated the RFID antenna structure  100  in use with medication container. The RFID antenna structure  100  is formed into a circle and positioned within the interior of the lid  400  of the medication container. Specifically, the RFID antenna structure  100  is positioned against the threads  402  of the lid  400 . Thus, once the lid  400  is screwed on the container, the edge  202  would contact the metal foil sealing disk of the container creating an edge on to the metallic surface. Typically, the RFID antenna structure  100  comprises a biaxially polypropylene (BOPP) face and a permanent adhesive to secure the RFID antenna structure  100  in the lid  400 , however any other suitable materials can be used as is known in the art. 
       FIG. 5  illustrates the RFID antenna structure  100  positioned in the same orientation but within a larger lid  500  of a medication container. Further, the action of the lid threads  402  engaging when the lid  500  is screwed on does not destroy the RFID antenna structure  100 , and even after multiple tries, as well as over-tightening the lids  400  and  500 , the RFID antenna structure  100  still functions. With reference now to  FIG. 6 , there is illustrated a graph of the performance of the RFID antenna structure edge on to a foil sealing disk. 
     With reference now to  FIGS. 7A-B , the RFID antenna structure  700  is shown. Specifically,  FIG. 7A  discloses the RFID antenna structure  700  configured as an RFID inlay  702  sandwiched between two sheets of material  704 , such as paper, plastic, or foam. Specifically, the material is typically laminated around the material  704  and then cut into shapes, such as circles, rectangles, hexagons, triangles, etc., or any other suitable shape as is known in the art. When mounted on a metal surface so that the edge  706  of the RFID inlay  702  is in proximity to the metal surface, good performance is achieved. 
       FIG. 7B  discloses a side view of the RFID antenna structure  700 . The RFID inlay  702  is shown sandwiched between two layers of material  704  (i.e., paper, plastic, or foam). Thus, the RFID inlay  702  is capable of operating on metal surfaces when made by flat roll to roll lamination and slitting or die cutting, or any other suitable method as is known in the art. 
     With reference now to  FIG. 8 , the RFID antenna structure  800  is shown wrapped around a shape. Specifically,  FIG. 8  discloses the RFID antenna structure  800  configured as an RFID inlay  802  which is wrapped around a round object  804 , such as a plastic disk or any other suitable shape as is known in the art. If the disk has a hole, then the RFID inlay  802  can be wrapped around an internal surface of the disk, such as a thread or other area. The RFID inlay  802  in either configuration is then placed in edge on proximity to a metal surface  806 , such as a foil disk used to seal a medicine container, or any other suitable metal surface as is known in the art. 
     With reference now to  FIG. 9 , the RFID antenna structure  900  is shown extruded inside a plastic strip  904 . Specifically,  FIG. 9  discloses the RFID inlay  902  extruded into a plastic strip  904 , wherein the RFID inlay  902  is positioned down the center of the extrusion.  FIG. 9  shows a triangular cross-section, but alternate multi-sided shapes can be used as well, as is known in the art. The RFID inlay  902  is then placed on its edge  906  proximate to any suitable metal surface as is known in the art. 
     With reference now to  FIG. 10 , the RFID antenna structure  1000  is disclosed as being wound helically around a narrower former. Specifically, in order to reduce the diameter of the structure without making the ends of the RFID inlay  1002  overlap, the RFID inlay  1002  is wound helically around a narrower plastic former  1004 . This plastic former  1004  can include a hole  1006  to allow the structure  1000  to be fixed by a bolt or screw to a surface, or any other attachment means as is known in the art. The RFID inlay  1002  is then able to be mounted such that the edge of the 
     RFID inlay  1002  is in proximity to the metal surface. 
     With reference now to  FIG. 11 , the RFID antenna structure  1100  is disclosed as being formed into a flat spiral. Specifically, the RFID inlay  1102  is wound into a flat edge spiral that can be attached to a metal surface  1106 . Thus, the RFID inlay  1102  in the shape of a spiral can be placed edge on a metal surface  1106  to achieve good performance of the antenna structure  1100 . 
     With reference now to  FIGS. 12A-B , the RFID antenna structure  1200  is shown as being attached to a metal surface in different mounting orientations. Specifically, the figures show an RFID inlay  1202  embedded within a plastic material  1204 , or any other suitable material. The embedded RFID inlay  1202  has two mounting surfaces that can be attached to a metal surface  1206 . Depending on which surface is attached, the tuning and other properties of the RFID antenna structure  1200  can be changed. Further, other structures such as a hexagonal cross-sectional structure, allow multiple mounting orientations which can give different tuning states. 
     With reference now to  FIGS. 13A-C , the RFID antenna structure  1300  is applied to twist cap containers  1302  as a tamper evident device. Specifically, as shown in  FIG. 13A , a label  1304  is positioned over a twist cap  1306  and over the container (or bottle)  1302  neck with an RFID inlay  1308  positioned only over the container (or bottle)  1302 . A perforation strip  1310  is engineered over the label  1304  and the RFID inlay  1308 . Twisting of the cap  1306  to expose the container  1302  opening, propagates the tearing in and along the weakened path (i.e., perforation strip  1310 ) across and down through the label  1304  and inlay  1308  on the container  1302 , disabling the inlay  1308  (as shown in  FIG. 13B ). Thus, the RFID inlay  1308  is disabled when the cap  1306  is twisted off (i.e., the bottle is opened). 
     Furthermore, the perforation strip  1310  can be any engineered path that propagates a tear along a predetermined path, such that the predetermined path may be defined as any designed/engineered weakening in the label/inlay construction. In a preferred embodiment, the weakening is by perforation or scoring of certain layers in the label/inlay construction. In a further embodiment shown in  FIG. 13C , the label  1304  comprises no or a reduced adhesion in certain areas  1312 . These areas  1312  of little or no adhesive facilitate ease of separation of the perforated path through the label  1304  and inlay  1308 . 
     With reference now to  FIGS. 14A-B , the RFID antenna structure  1400  is applied to fliptop cap containers  1402  as a tamper evident device. Specifically, as shown in  FIG. 14A , a label  1404  is positioned over a flip-top cap  1406  and over the container (or bottle)  1402  neck with an RFID inlay  1408  positioned over the flip-top can  1406  and over the container (or bottle)  1402  as well. A perforation strip  1410  is engineered over the label  1404  and the RFID inlay  1408 . Flipping open the cap  1406  to expose the container  1402  opening, propagates the tearing in and along the weakened path (i.e., perforation strip  1410 ) across and down through the label  1404  and inlay  1408  on the container  1402 , disabling the inlay  1408  (as shown in  FIG. 14B ). Thus, the RFID inlay  1408  is disabled when the cap  1406  is flipped open (i.e., the bottle is opened). Furthermore, the perforation strip  1410  can be any engineered path that propagates a tear along a predetermined path, such that the predetermined path may be defined as any designed/engineered weakening in the label/inlay construction. In a preferred embodiment, the weakening is by perforation or scoring of certain layers in the label/inlay construction. 
     With reference now to  FIGS. 15A-C , the RFID antenna structure  1500  is applied to fliptop cap containers  1502  as a tamper evident device. Specifically, as shown in  FIG. 15A , a label  1504  is positioned over a flip-top cap  1506  and over the container (or bottle)  1502  neck with an RFID inlay  1508  positioned only over the container (or bottle)  1502 . A perforation strip  1510  is engineered over the label  1504  and the RFID inlay  1508 . Flipping open the cap  1506  to expose the container  1502  opening, propagates the tearing in and along the weakened path (i.e., perforation strip  1510 ) across and down through the label  1504  and inlay  1508  on the container  1502 , disabling the inlay  1508  (as shown in  FIG. 15B ). Thus, the RFID inlay  1508  is disabled when the cap  1506  is flipped open (i.e., the bottle is opened). 
     Furthermore, the perforation strip  1510  can be any engineered path that propagates a tear along a predetermined path, such that the predetermined path may be defined as any designed/engineered weakening in the label/inlay construction. In a preferred embodiment, the weakening is by perforation or scoring of certain layers in the label/inlay construction. In a further embodiment shown in  FIG. 15C , the label  1504  comprises no or a reduced adhesion in certain areas  1512 . These areas  1512  of little or no adhesive facilitate ease of separation of the perforated path through the label  1504  and inlay  1508 . 
     What has been described above includes examples of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art may recognize that many further combinations and permutations of the claimed subject matter are possible. Accordingly, the claimed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term “includes” is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term “comprising” as 
     “comprising” is interpreted when employed as a transitional word in a claim.