Product counterfeiting has long been a problem for brand owners. Manufacturers are rightly concerned about the protection of their brand image and wish to control the distribution of their products and to monitor the levels of counterfeit product in the world marketplace.

European Patent Application (EP0317202A) discloses a novel tear strip or sealing strip for a package or container. The tear strip or sealing strip comprises a plastic film substrate upon which a magnetisable metal oxide coating has been deposited. The coated strip may be adhered to the package or the flexible wrapping material for the package or container. Optionally, the strip may be coated with a pigment or metallised or printed with graphic indicia or any combination of these features. Information may be recorded on the magnetic coating during packaging and handling for subsequent read-out.

This prior magnetic system has not had commercial success, primarily for two reasons : Firstly, contact reading devices are required in order to read out any information on the magnetised metal oxide coating ; n. b. - and secondly, any such recorded information can easily be erased by bringing the sealing strip or tear strip into a powerful AC

magnetic field.

The present invention aims to obviate or at least ameliorate these problems.

According to one aspect of the present invention there is provided a method of verifying the authenticity of merchandise or of uniquely identifying a particular batch or pack of merchandise, which comprises incorporating in, or securing to, at least one component of the packaging in which the merchandise is packaged for distribution and/or sale, a magnetically coded strip having a predetermined pattern of high permeability, low coercivity magnetic elements exhibiting zero or very low remanence.

The remanence of a material is a measure of the magnetic flux remaining in a ferromagnet when the saturating magnetic field is reduced to zero. It therefore represents the ability of a material to become permanently magnetised. The magnetic material used in this aspect of the present invention is not magnetisable in the conventional sense, since it exhibits zero or very low remanence and consequently, it is not susceptible to permanent change in its magnetic properties by exposure to a strong magnetic field (as is the case, for example, when magnetic recording tape or other materials containing a magnetisable metal oxide coating are used for security applications).

According to a second aspect of the present invention there is provided a magnetically coded strip which provides means of verifying the authenticity of merchandise, or of uniquely identifying a particular batch or pack of merchandise, characterised in that the

strip comprises a predetermined pattern of high permeability, low coercivity magnetic elements exhibiting zero or very low remanence, wherein said magnetically coded strip is incorporated in, or secured to, at least one component of merchandise packaging.

Suitable magnetic materials for use with the present invention include thin film materials such as ATALANTE from IST, and amorphous spin melt materials such as Vacuumschmeltze 6025 and 6006.

The high permeability, low coercivity magnetic material may be located on the surface of a component of the packaging material or it may be embedded within a relatively thin component (e. g. in the paper or plastics material from which a packaging carton is made). In the particular case of cigarette packaging, the magnetic material may be embedded within the tear- off strip which forms part of the foil wrapping material ; alternatively, or in addition, a high permeability, low coercivity magnetic material may be coated on to part of the carton, for example between the inner frame and the outer.

According to a third aspect of the present invention there is provided a system for use in verifying the authenticity of merchandise, or for use in uniquely identifying a particular batch or pack of merchandise, comprising : (i) a magnetically coded verification strip, provided on or within at least one component of the merchandise packaging, wherein said verification strip comprises high permeability, low coercivity magnetic material which exhibits zero, or very low, remanence ; and (ii) means for interrogating the verification

strip so as to read the information stored on or within said strip.

By virtue of the properties of the magnetic material, the existence of such a high permeability, low coercivity magnetic strip cannot easily be detected by optical means or by conventional magnetic readers.

The preferred means for detecting and/or reading a coded magnetic strip in the method of this invention involves the technology described in our International Patent Publication No. WO 96/31790 which exploits the difference between the magnetic behaviour of a magnetically active element when subjected to (i) a region of zero magnetic field, known as a magnetic null, and (ii) a high, saturating magnetic field. The disclosure of WO 96/31790 is incorporated herein by reference thereto ; for convenience the technology described therein will be referred to hereinafter as "FN technology".

Any convenient techniques for coding the soft magnetic material may be employed. It is preferred, however, to use techniques such as are described in our International Patent Publications Nos. WO 96/31790 and WO 97/04338. The disclosure of WO 97/04338 is incorporated herein by reference thereto.

One such method of storing information on a magnetic tag involves attaching to the tag a plurality of magnetically detectable elements, the geometrical arrangement of which provides a code relating to the information being stored. By employing FN technology to interrogate the tag, a relationship may exist between the geometrical arrangement of the magnetic strips and the detectable change in magnetic field pattern, arising due to fluctuations in the direction of

magnetic saturation of the strips, as the element is subjected to first a zero field and then a high, saturating field.

A further method of storing information involves the use of a tag formed from a continuous strip of high permeability material, discrete regions of which have their magnetic properties permanently or temporarily modified. In relatively simple embodiments, each magnetically active region has the same magnetic characteristics ; in more complex embodiments, each magnetically active region can possess a different magnetic characteristic.

Magnetic reading devices at least some of which will be of benefit in conjunction with the present invention are disclosed in, for example, our subsequent International Patent Publications Nos. WO 97/48990 and WO 98/15851 the disclosure of each of which is incorporated herein by reference thereto. A number of possible embodiments are described in these applications employing either permanent magnets or electromagnets to create the required magnetic field configuration. One particular implementation works by detecting the harmonics of a superimposed low-amplitude alternating interrogation field.

Preferably, the high permeability, low coercivity magnetic material is applied to the surface of the packaging components by hot-foil stamping, adhesion or lamination. In one embodiment, the magnetically coded strip is applied to the total length of the tear-off strip ; the magnetic code can then appear repeatedly along the length of the strip. In another embodiment, the high permeability, low coercivity magnetic material is located in a predetermined location along the length

of the tear-off strip, the arrangement being such that the coded information stored in the magnetic strip is located in a predetermined position with respect to the face of the carton. This arrangement requires proper registration between the carton and a magnetic read-out head when the magnetically coded information is to be retrieved.

According to a fourth aspect of the present invention, there is provided a magnetically coded strip which provides means of verifying the authenticity of merchandise or uniquely identifying a particular batch or pack of merchandise, characterised in that the strip comprises a layer of a first high permeability, low coercivity magnetic material, and a layer of a second magnetic material carrying, or capable of carrying, a recorded magnetic pattern, wherein said magnetically coded strip is incorporated in, or secured to, at least one component of merchandise packaging.

According to a fifth aspect of the present invention, there is provided a method of verifying the authenticity of merchandise or uniquely identifying a particular batch or pack of merchandise, which comprises incorporating in, or securing to, at least one component of the packaging in which the merchandise is packaged for distribution and/or sale, a magnetically coded strip comprising a layer of a first high permeability, low coercivity magnetic material, and a layer of a second magnetic material carrying, or capable of carrying, a recorded magnetic pattern.

As mentioned above, a magnetically coded strip may be mounted between the inner frame and the outer frame of the cigarette package either instead of or in addition to the use of a similar material on the

tear-off strip of the packaging. The magnetic codes used may be of the read-only or programmable type.

Preferably, only part of the overall code is susceptible to programming ; in this way, the read-only component of the code may for example be used to relate to the packaging machine in which the product is being packaged, while the programmable component may be used to relate to the batch number. With such a system, writing information in the programmable component of the magnetic strip could take place on-line during the packaging process.

Advantageously, there may also be provided a means for generating a visual and/or audible confirmation of a valid readout, in order to demonstrate the authenticity of the merchandise or uniquely identify a particular batch or pack. This may preferably be provided within the device responsible for generating the interrogating magnetic field.

The invention will now be described by way of example, with reference to the accompanying drawings, in which : Figure 1 illustrates a package having a magnetically coded verification strip embedded into a tear-off strip ; Figure 2 illustrates an example of a magnetically coded strip ; and Figure 3 illustrates a second example of a magnetically coded strip.

Figure 1 shows a diagrammatic representation of a package 14, for example a pack of cigarettes, in which

a tear-off strip 12 carries a high permeability, low coercivity magnetic material (indicated at 13, although not visually discernible from the remainder of the strip 2) which has been encoded in the manner disclosed in WO 96/31790.

Figure 2 shows one example of a magnetically coded strip 10 in accordance with the present invention. The strip comprises seven square elements 11 of high permeability, low coercivity material which are all physically identical, both in terms of their magnetic properties and in terms of their size. The magnetic elements have been secured to a substrate strip in a predetermined manner, such that their geometrical arrangement provides a code relating to the information being stored. This arrangement may be repeated along the whole length of the tear-off packaging strip, or it may positioned at a predetermined location along the tear-off strip. The magnetic elements 11 in this embodiment have a width of 4x and have been arranged such that the gaps between the elements vary between x and 8x. Specifically, the size of the gaps in this example are easily represented in the following table in which reference letters A to F denote the gaps shown in Figure 2. A B C D E F Size X 2x 4x 5x 3x 8x The reader should appreciate however, that the specific relationship between the width of these elements and the gaps between them are given merely by way of example.

Figure 3 illustrates another example of a magnetically coded strip which may be used in the present invention. The strip 20 comprises two layers of

magnetic material in which the top layer 21 is a hard or semi-hard magnetic material and the bottom layer 22 is a high permeability, low coercivity material. The top layer 21, has been permanently magnetised so as to exhibit distinct regions (not shown) of varying magnetic property such that its local magnetic field pattern varies across its length. This provides a method of encoding the bottom layer 22, since it will experience varying levels of magnetic flux along its length due to the recorded magnetic patterns in the top layer 21. Since these recorded patterns may be erased and new patterns recorded on their place, this embodiment provides a programmable coded srip.

However, it should be appreciated that although this embodiment may be easily employed in the present invention, the preferred embodiment is one which utilises distinct elements of high permeability, low coercivity material, as illustrated by Figure 2.