Radio frequency identification (RFID) tag

This application claims priority from <patcit id="pcit0001" dnum="US61354758B"><text>US Provisional Patent Application No. 61/354,758 filed on 15 June 2010</text></patcit>.

This invention relates to a radio frequency identification (RFID) tag and various applications of such an RFID tag.

With the rapid popularity of RFID technology in many industries, its use in the apparel industry is becoming more prominent Currently, RFID tags are mostly attached to price tags, which may be mounted either at the retail shop, or at the distribution center of the retail shop, or even at the factory. The purpose of RFID tags as attached to the price tags of apparel is mainly for logistics and price management. Often, the RFID tag is used for anti-theft purposes.

An additional purpose that is just becoming a requirement is for anti-counterfeiting purpose. For expensive branded clothing or bags, the need for anti-counterfeiting is of utmost importance. This application of RFID technology is to protect intellectual property rights of the brand and to insure authentication. In this application. just applying an RFID tag to a price tag is not sufficient, as the price tag is a separate item and can be easily counterfeited. The RFID tag must be hidden inside the bag or clothing or made difficult to access.

Another problem of apparel is the process of washing and the need to sort out the ownership of each piece of clothing after the washing cycle. This is particularly important for management of uniforms of hotels, schools, police, military, costumes and etc.

It is thus an objective of the present invention to provide a novel RFID tag, ways of using such an RFID tag, and methods of attaching such an F:FID tag to an object, in which the aforesaid shortcomings can be mitigated.

According to a first aspect of the present invention, there is provided a radio frequency identification (RFID) tag including an integrated circuit and at least one antenna connected with said integrated circuit, wherein said at least one antenna is formed of an at least partly metalized thread.

According to a second aspect of the present invention, there is provided a method of attaching at least one radio frequency identification (RFID) tag to an object, wherein said RFID tag includes an integrated circuit and at least one antenna connected with said integrated circuit, wherein said at least one antenna is formed of an at least partly metalized thread, said method including sewing or weaving at least said thread of said RFID tag to said object.

According to a third aspect of the present invention, there is provided a method of attaching at least one radio frequency identification (RFID) tag to an object, wherein said RFID tag includes an integrated circuit and at least one antenna connected with said integrated circuit, wherein said at least one antenna is formed of an at least partly metalized thread, said method including positioning said thread through or around said object or a part of said object.

According to a fourth aspect of the present invention, there is provided a method of forming a tamper-destruct seal for an object, said method including providing at least one radio frequency identifcation (RFID) tag, wherein said RFID tag includes an integrated circuit and at least one antenna connected with said integrated circuit, wherein said at least one antenna is formed of an at least partly metalized thread, and associating said thread with said object.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figs. 1A to 1E</figref> show various objects into or onto which an FRID tag according to the present invention may be embedded or fixedly secured;</li><li><figref idref="f0002">Fig. 2</figref> shows an RFID tag according to the present invention sewn in a piece of cloth;</li><li><figref idref="f0002">Fig. 3</figref> shows an RFID tag according to the present invention with its centre part mounted on a piece of FR4 printed circuit board;</li><li><figref idref="f0003">Fig. 4</figref> shows an RFID tag according to the present invention with its centre part mounted on a piece of inlay;</li><li><figref idref="f0003">Fig. 5</figref> shows an RFID tag according to the present invention with its centre part on a piece of cloth;</li><li><figref idref="f0004">Fig. 6</figref> shows a clothing item, being a shirt, sewn with three RFID tags according to the present invention;</li><li><figref idref="f0004">Fig. 7</figref> shows an RFID tag according to the present invention with two dipoles;</li><li><figref idref="f0005">Fig. 8</figref> shows an RFID tag according to the present invention with a loop style antenna;</li><li><figref idref="f0006">Figs. 9A and 9B</figref> show a number of metalized threads of various diameters, which may used in an RFID tag according to the present invention;</li><li><figref idref="f0007">Fig. 10</figref> shows an RFID tag according to the present invention connected with and powered by a thin film battery;</li><li><figref idref="f0007">Fig. 11</figref> shows an RFID tag according to the present invention with its centre part covered with plastic to improve or achieve water-proofing;</li><li><figref idref="f0008">Fig. 12</figref> shows an RFID tag according to the present invention with its centre part covered by a piece of cloth;</li><li><figref idref="f0008">Fig. 13</figref> shows an RFID tag according to the present invention attached to a clothing item and a label of the clothing item;</li><li><figref idref="f0009">Fig. 14</figref> shows an RFID tag according to the present invention connected with metalized threads of different colours:</li><li><figref idref="f0009">Fig. 15</figref> shows an RFID tag according to the present invention with a metalized thread received through a ring;</li><li><figref idref="f0010">Fig. 16</figref> shows an RFID tag according to the present invention wound around a cow;</li><li><figref idref="f0010">Fig. 17</figref> shows an RFID tag according to the present invention attached to an earlobe of a cow;</li><li><figref idref="f0011">Fig. 18</figref> shows an RFID tag according to the present invention attached to a document as a tamper-destruct seal;</li><li><figref idref="f0011">Fig. 19</figref> shows an RFID tag according to the present invention forming part of a container cover as a tamper-destruct seal for the container;</li><li><figref idref="f0012">Fig. 20</figref> shows an RFID tag according to the present invention attached to a shoe lace of a shoe; and</li><li><figref idref="f0012">Fig. 21</figref> shows an RFID tag according to the present invention weavec into a bag or sack.</li></ul>

<figref idref="f0001">Figs. 1A to 1E</figref> show various objects into or onto which a radio frequency identification (FRID) tag according to the present invention may be secured. <figref idref="f0001">Fig. 1A</figref> shows a piece of cloth 12 onto which such an RFID tag may be secured; <figref idref="f0001">Fig. 1B</figref> shows a table cloth 14 onto which such an RFID tag may be secured; <figref idref="f0001">Fig. 1C</figref> shows a carpet 16 onto which such an RFID tag may be secured; <figref idref="f0001">Fig. 1D</figref> shows a shirt 18 onto whose label 20 such an RFID tag may be secured; and <figref idref="f0001">Fig. 1E</figref> shows uniforms 22 onto or into which such an RFID tag may be secured. The RFID tag may also be sewn onto leather or other wearable materials.

An RFID tag 24 according to the present invention is shown in <figref idref="f0002">Fig. 2</figref> as sewn onto a piece of cloth 26. The tag 24 is shown here as a passive RFID tag, although it should be understood that such may be a battery assisted passive RFID tag or an active RFID tag. The RFID tag 24 includes a flip chip integrated circuit (IC) 28 electrically connected with a pair of metalized threads 30, eacr forming an antenna of the RFID tag 24. The metalized threads 30 are normal thread, which may be made of cotton or polyester, totally recyclable, with metallization on the surface of the threads 30 or integrated into the threads 30. The threads 30 may be fully metalized or partly metalized with an electrically conductive metal, so as to render the threads 30 electrically conductive. Both fully metalized and partly metalized threads will be herein collectively referred to as "metalized threads". The metalized threads 30 are applied to the piece of cloth 26 by a sewing rr achine. The IC 28 may first be mounted on another substrate and then also sewn onto the piece of cloth 26. Altematively, the IC 28 may be sewn onto the clothing label, or to the clothing in its final embodiment.

<figref idref="f0002">Fig. 3</figref> shows the RFID tag 24 with its centre part (meaning the IC 28 and part of each of the two metalized thread antennas 30 connected with and closest to the IC 28) mounted on a piece of FR4 printed circuit board (PCB) with a plurality of metalized holes, The antennas 30 are received through and connected with a respective of the metalized holes. The threads 30 are in then sewn onto the piece of cloth 26. The flip chip IC 28 is covered with glue to make it waterproof and to give it structural strength so that it will less likely be loosened out when under mechanical stress.

<figref idref="f0003">Fig. 4</figref> shows the RFID tag 24 with its IC 28 mounted on a piece of plastic inlay 34. In a further possible arrangement, and as shown in <figref idref="f0003">Fig. 5</figref>, the flip chip IC 28 is mounted on a piece of cloth 36.

Although each object (be it a piece of cloth, a clothing item, or the like) may be associated with one RFID tag 24 only, it is of course possible to have more than one RFID tag 24 attached to an object. For example, and as shown in <figref idref="f0004">Fig. 6</figref>, three RFID tags 24 are sewn onto three different parts of a shirt 38 to provide redundancy of reading capacity, so that even if one or more of the RFID tags 24 is blocked or destroyed or in any way incapable of functioning properly, the remaining RFID tag(s) 24 can still respond to a reader request.

<figref idref="f0004">Fig. 7</figref> shows another RFID tag 40 with two pairs of melalized thread antennas 42 electrically connected to a central flip chip IC 44, to provide antenna diversity so that reader signals coming in at different polarization can still be read.

<figref idref="f0005">Fig. 8</figref> shows another RFID tag 46 with a flip chip IC 48 electrically connected to a loop style antenna made of a metalized thread 50. By way of such an arrangement, the RFID tag 46 can be read by a near field antenna based RFID reader, even if the whole piece of clothing or cloth (of which a part 52 is shown) is inside water or close to metal or close to human flesh.

As shown in <figref idref="f0006">Figs. 9A and 9B</figref>, metalized threads 54a, 54b, 54c, 54d, 54e, 54f, 54g. 54h, 54i, 54j, 54k, 541, 54m, 54n for forming antennas of RFID tags according to the present invention may be of various diameters (as shown in <figref idref="f0006">Figs. 9A and 9B</figref>) 50 as to provide various degrees of sensitivity to the RFID tags.

The RFID tags according to the present invention so far discussed are passive RFID tags. As mentioned above, RFID tags according to the present invention may be battery assisted passive RFID tags or active RFID tags. As shown in <figref idref="f0007">Fig. 10</figref>, the RFID tag 24 according to the present invention with an IC 28 attached with two metalized thread antennas 30 is connected with and powered by a thin film battery 56. The thin film battery 56 is mounted on a piece of cloth or paper, and is then sewn to the object (e.g. a clothing item) to which the RFID tag 24 is to be sewn. This enables the RFID tag 24 to behave as a battery assisted tag, thus allowing ultra long read range.

As shown in <figref idref="f0007">Fig. 11</figref>, the RFID tag 24 according to the present invention with a central IC 28 attached with two metalized thread antennas 30 is overed by a piece of malleable conformable plastic material to achieve or improve waterproofing. In addition or as an alternative to being covered by a piece of plastic material, and as shown in <figref idref="f0008">Fig. 12</figref>. a further piece of cloth 60 may be sewn onto the object to cover the centre part of the RFID tag 24, i.e. the flip chip IC 28 and the part of the metalized thread antennas 30 which are close and connected to the flip chip IC 28.

As shown in <figref idref="f0008">Fig. 13</figref>, for an RFID tag 40 with two pairs of metalized thread antennas 42a, 42b electrically connected with a central IC, a part o1' each of the antennas 42a is sewn onto a label 62 of a piece of clothing 64 and a part of each of the antennas 42a is sewn onto the piece of clothing 64. This allows a larger antenna for best read range.

As shown in <figref idref="f0009">Fig. 14</figref>, for an RFID tag 40 with a number of metalized thread antennas 42 connected with a central IC, the antennas 42 may be of different colours, so as to guide the user to use a pair of scissors to cut the proper thread (which may, for example, be of a colour different from that of all other threads) to permanently terminate the operation of the RFID tag 40.

Metalized thread based RFID tags have many applications, including the application onto price tags of such jewellery items as gold or jewel rings and watches and other valuable goods in retail shops. As shown in <figref idref="f0009">Fig. 15</figref>, an RFID tag 24 according to the present invention is attached to a ring 68 by having its loop style metalized thread antenna 66 received through the ring 68. A pr ce tag 70 is attached (e.g. glued) onto the IC of the RFID tag 24. The thread antenna 66 may be fully metalized or partly metalized to obtain different antenna effects.

As shown in <figref idref="f0010">Fig. 16</figref>, a metalized thread based RFID tag 24 is shown as being applied to a string or woven collar 72 worn around the neck of a cow. The string or woven collar 72 may be worn around body parts of various other animals, e.g. dogs, cats, or other pets, with the string or woven collar selectivity metalized with the proper length according to RF requirements, so as to act as an antenna. A cloth or paper based card may be provided to house the flip chip IC 28. It is found in practice that if the string or woven collar is partially metalized, the read range of the RFID tag 24 (when mounted on the animal) can be maximized.

As shown in <figref idref="f0010">Fig. 17</figref>, a metalized thread 30 attached to a central IC of an RFID tag 24 can also be directly sewn into a body part of an animal or livestock, such as an earlobe of a cow, or a fin of a fish, and the antenna design can be optimized for the animal body such that the read range can be relatively good. The RFID tag 24 is thereby attached to the animal.

Metalized thread based RFID tags can also be used as tamper-destruct seals for legal documents. A tamper-destruct seal for legal documents is shown in <figref idref="f0011">Fig. 18</figref> and generally designated as 80, including a seal 82, a metalized thread antenna 84 and an RFID IC 86 connected with one another. The metalized thread antenna 84 and the IC 86 form an RFID tag 90. A legal document 88 is also shown in <figref idref="f0011">Fig. 18</figref> as being protected by the tamper-destruct seal 80. In particular, the tamper-destruct seal 80 is associated with the legal document 88 by having its metalized thread antenna 84 positioned through one or more holes (not shown) of the document 88 in such a manner that any tampering will destroy the antenna 84 and render the tag 90 unreadable beyond a certain distance, thus signaling to the user that the document 88 has been tampered with.

Metalized thread based RFID tags can also be used as tamper-destruct seals for container caps. As shown in <figref idref="f0011">Fig. 19</figref>, an RFID tag 24 with an RFID IC 28 electrically connected with a metalized thread 30 is associated with a bottle by having the thread 30 fixedly connected to a breakable part of a cap 92 of the bottle. The opening of the cap 92 will break the metalized thread 30 and break the critical conductive path needed in the RFID tag 24, thus disabling the tag 24.

Metalized thread based RFID tags can also be applied to shoe lace for athletes or kids where their where about or sequence on the road need lo be tracked or gauged. In particular, as shown in <figref idref="f0012">Fig. 20</figref>, a shoe lace 96 of each shoe 98 is sewn with an RFID tag 24 according to the present invention. The metalized thread antennas of the tags 24 are sewn or woven into the shoe laces 96 of the shoes 98 so as to attach the RFID tag 24 to the respective shoe 98.

As shown In <figref idref="f0012">Fig. 21</figref>, metalized thread based RFID tag can also be applied to sack or bag made of cloth or linen or plastic fiber for industrial or agricultural use, so that the contents in the sack or bag can be tracked from the farm to the factory. In such a case, the centre part housing the flip chip RFID IC needs to be properly protected (e.g. being covered by a piece of hard plastic) to protect the IC from being damaged by weight or impact, and the metalized threads of the RFID tag are woven onto or into the sack or bag. A metalized film, either in dipole far field form or loop near field form. or both, may be provided to provide long range RFID read even when the goods inside the sack contains water or meat, or even metal.

In summary, metalized thread based RFID tags can be used in many aspects of our life and provide the necessary antenna structure for beat and longest range RFID read in a most natural way of attachment or integration into our clothing wear and as a wearable device.

It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention.

It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations.