Field of the Invention

The present invention relates to a casing comprising a booster coil. The invention further relates to a method for producing such a casing comprising a booster coil. In addition, the invention relates to a product containing an item contained in such a casing.

Background of the Invention

A casing for a Compact Disc (CD) or a Digital Versatile Disc (DVD) (herein disc casing) is used to store and carry digital media discs. However, a traditional disc casing lacks the function of information management.

Typically, the quantity of such disc casings in stock, in a store or warehouse for example, is determined by manual counting, or by manually scanning the bar code on the casings with a scanning device to obtain disc information. However, these methods are susceptible to defects and require a lot of time.

The disadvantages of these methods can be worked out by using Radio Frequency Identification (RFID) detection of discs, for example, based on High Frequency (HF) RFID technology. In some RFID implementations, HF means 13.56 MHz frequency used in ISO 18000, ISO 15693 and ISO 14443 standards.

One solution using RFID detection is disclosed in the publication US2006/0185995A1 , where a DVD box comprises a main body and an RFID tag and the RFID tag with disc information is attached onto or installed inside the main body of the DVD box. This solution has several drawbacks: it provides identification of the DVD box only, not of the disc contained inside it, it is rather expensive, and the manufacturing and installation of a chip inside the box main body requires extra stages, such as embedding and injection molding.

Besides adding an RFID tag onto the casing or inside the main body of the casing, RFID detection can be applied on the disc itself by using an RFID tag attached to the disc. A significant known problem encountered with RFID labelling CDs or DVDs is associated with the metallic coatings on the media which interfere with the RF interrogation operation. In particular, mounting an RFID tag to a digital media disk having metallic coatings can reduce the effective detection range to impractically short distances, for example 10 to 20 cm. This means that the detection range becomes too short to provide adequate security, for example, in library use or in shops. In other words, the items can be inadvertently or deliberately removed from the premises without detection.

Patent publication WO07027160A2 proposes a solution for the above problem by providing two separate RF transponders, one mounted on the data storage medium (disc) and the other on the associated container. This improves the detectivity of items to be processed.

Further, it is possible to use a booster to enhance the function of an RFID tag of a disc. Basically, a booster is a separate RF coil, which is inductively or capacitively coupled to another RFID tag, thus enhancing the function of the latter and improving the interrogation distance. Traditionally, a larger etched aluminium booster coil can be attached in a label-like manner on the disc surface to enhance the interrogation distance of the primary RFID tag. Such technology utilized in magnetic RF couplings to enhance the function of an RFID tag of a media disc is known as such. A significant drawback related to the use of the booster coils is that they are rather expensive and require a large area of metal for etching the coil.

The boosting effect of media disc identification is often required especially at portal gates capable of multi-read application. Typically with a booster, the Electronic Article Surveillance (EAS) function at portal gates for a metalized media discs with RFID tags can be matched to an almost equal level to that with book tags or similar where no metal interference for the RF interrogation is involved. The multi-read function is often required, for example, for disc collections products, where there are several tagged discs in one package.

Considering the above mentioned limitations of the RFID tags on CDs, DVDs or similar objects even when equipped with booster coils, there is a need for a novel solution to enhance the RF interrogation of such items especially when they are handled in their casings and one casing could include even several tagged items. Further, the new solution should be easy, inexpensive and environmentally friendly to manufacture without compromising the RFID performance.

Summary of the Invention

The present invention is based on producing, for example printing a booster antenna with electrically conductive ink directly on a cardboard or similar natural fiber based material casing, typically on the inner side of the cardboard casing. The use of cardboard for the casing is an economical and environmentally friendly option to produce a casing. The use of such printable material provides the possibility to apply the booster directly, on the casing, using printing technology.

In the following, the invention is explained by using CDs, DVDs or other high- value RFID tagged products as an example. However, the invention is not limited for providing booster casings for such items only but it is applicable to any other high-value RFID tagged items that could be packaged into boosted cardboard casings. Here the term cardboard should also be interpreted here widely covering all similar materials manufactured from paper or other fresh or recycled natural fiber materials.

The printed booster according to the invention will boost the RF signal of the RFID tag of a disc for RFID detection to be reliably counted and identified without an expensive and large booster attached in a label-like manner on the disc surface. The term "disc" refers in this context to any disc, CD, DVD etc. with an RFID tag, suitable to be stored and/or transported with a disc casing, and the term "casing" refers in this context to any casing, package, box, folder, etc., suitable for having a printing and for storing and/or transporting discs or other items with RFID tags.

The aim of the present invention is to create a cardboard casing comprising a booster produced by applying electrically conductive ink directly on a cardboard casing, typically on the inner side of the casing. The booster coil enhances the function of an RFID tag of the item packaged in the casing, for example a disc. The booster couples itself inductively to the RFID tag of the item and gives better performance. An on-line printed booster with exact tuning of the coil is a flexible and cheap method for boosting the RFID signal.

Further, the aim of the present invention is to offer an inexpensive and functional solution to produce casings with discs for automatic identification of discs in different environments.

Description of the Drawings

In the following, the invention will be described with reference to the appended figures in which

Fig. 1 shows a working mechanism of a prior art booster tag, Fig. 2 shows a front view of a booster coil inside the CD casing, and Fig. 3 shows a schematic description of the booster coil structure.

Detailed Description of the Invention

Conventionally, a plastic casing is used for a disc. However, with the present- day sophisticated packaging technology, new ways for disc packaging are being developed. Packages and casings made of more natural and environmentally friendly materials are becoming even more popular. The current invention makes efficient use of such new packages/casings which enable printing a booster coil for the RFID tag with disc information directly on cardboard. These kinds of production lines are fully automatic with digital (individual, Variable Information Printing, VIP) printing units and match the contents of the disc to the package. When the printing capability is included in the machinery itself, a printed booster coil can be managed on-line when manufacturing the disc or other item for sale. The same idea can, of course, be used for plastic disc casings, but as these are often manufactured in an injection moulding process, the attachment of a booster can typically only be done offline. In addition, in disc packaging lines using cardboard material, the antenna printing unit can be integrated directly in the machinery, and thus the discs to carry the booster can be selected one by one.

The booster coil is produced with electrically conductive ink or other galvanically conducting material directly on the cardboard disc casing, preferably on its inner side. Typically, the pattern of the booster coil is printed on the casing or the blank thereof. The ink may contain electrically conductive particles, such as silver or copper. It should be noticed that usually it is more practical to print a booster coil on a blank for casing, on a place intended to be the cover of the casing, before the actual casing is formed from the blank by folding it etc. In addition, it is possible to print booster coils on a web, for example on a cardboard web, before cutting the web into pieces suitable to be used for casings.

Typically, the printed booster comprises a tuned outer coil fitted into the package, connectors to inner coil, and a tuned inner coil connected to the RFID tag itself. This format may vary, depending on the package. The basic idea is to use a printed coil with at least one turn on the casing itself. In the case of a booster for a CD, DVD or other media disc, the area of this outer coil should be larger than the disc in the casing itself or at least larger than the metallic area on the disc. This size and location of the outer coil enables the booster coil to boost one RFID tag of a multi disc and even more than one RFID tag in a case of multi disc casings. So, even in the case of multi disc casings, one booster coil on the package can boost the magnetic field for the whole multi disc casing. This outer coil should be tuned to work at a predetermined frequency, for example at a frequency of 13.56 MHz. The connectors to the inner coil should be carefully designed in order to avoid extra parasitic capacitance between the connectors. The inner coil at the booster should be tuned to match the tuning of the RFID tag on the disc. The matching of the tuning between both the outer coil and the inner coil is attained by number of turns, turn line width, which reflects to conductivity, and turn cap. The total working frequency of the booster should be designed as a combination of the outer and inner coil frequencies and parasitic capacitances of the entire structure.

It should be noticed that the booster coil of the present invention is not limited to be printed on disc casings only, but it is also possible to use any other product comprising an RFID tag instead of a disc and to print the booster coil on the package of the product in question. These products may be packed separately and each booster coil according to this invention is adjusted to boost one or more RFID tag(s). In library use, the CDs or DVDs are packed in multi casings, like TV series, soap series etc. Automatic check-out requires a detection of all the discs, and the booster coil on the package can boost the magnetic field for the whole package/casing.

Cardboard disc casings may become more common in the future due to their environmentally friendly properties when compared to plastic casings. This enhances the value of the printing method for producing a booster antenna. In addition, cardboard casings can be easily closed with a tamper-proof tape (seal either the tape or the cardboard itself), which provides more security in new sales applications.

The method of printing the booster already on the cardboard package lowers the costs of the total solution and can be made on-line with modern machines. Having the print unit incorporated with the manufacturing of the package also gives the advantage that different designs of booster can be fitted into different packages, or certain individual packages of a selected production batch can even be left without the booster. There would be no need to store the expensive booster labels. In addition, cardboard casing covers comprising a printed booster coil are ecological packages when compared to conventional large etched aluminium CD boosters on plastic disc carriers, attached in a label-like manner to the CD surface.

Fig. 1 shows a working mechanism of a prior art booster tag 1. The booster tag 1 is manufactured separately on a substrate and then applied onto a plastic casing and connected to the CD tag 2 of a CD 3. The booster tag 1 couples itself inductively to the CD tag 2, and there is an air connection 4 between the booster tag 1 and CD tag 2.

Fig. 2 shows a front view of a preferred embodiment of the booster coil 5 of the invention. The booster coil 5 is printed directly on the inner side of a cardboard casing cover 6. In this case the casing is intended for a media disc. Printing the pattern of the booster coil on the surface of the casing that will become the inner surface after the casing has been folded and is ready, has the benefits that a) the outer surface can be used for other printing purposes, b) the booster coil is better protected by the casing, and c) the booster coil remains invisible from the outside, which improves the security effect obtained. So, when the casing is folded and ready casing (a formed casing) and when the formed casing is in its folded position, the printed booster coil 5 is opposite a place reserved for the media disc.

Fig. 3 shows a schematic description of the booster coil structure comprising an inner booster coil 7 with at least one turn and an outer booster coil 8 with at least one turn. There are connectors 9 between the inner coil 7 and the outer coil 8 and an electrical rest and an electrical bridge connection 10 is printed over the coils 7 and 8.

The above-mentioned embod iments do not restrict the scope of the invention. In addition, it is possible to use any suitable material instead of cardboard. The printed booster coil on the cover of the casing makes it possible to boost the RFID tag on the disc and furthermore to reliably count and identify the disk inside the casing by using RFID detection.