Abstract:
Authenticity/security identification consists of an optical marking and an (acoustic/electro)magnetic marking. The optical marking can comprise a hologram. The two identification marks are produced as a single entity during the production in a number of immediately successive steps. During this process a layer of soft magnetic material is provided with an additional layer of metal which contains the hologram.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is the 35 USC 371 national stage of international application PCT/NL99/00123 filed on Mar. 8, 1999 which designated the United States of America. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to an identification mark comprising an optically and an electronically readable marking. The electronic marking comprises an (acoustic/electro)magnetic marking, having a soft magnetic layer, and the optical marking comprises a structure provided with a relief. 
     BACKGROUND OF THE INVENTION 
     An identification mark of this type is disclosed in European Patent Application 0 673 853. This publication describes a security marking. A security marking is a marking which reacts to an acoustic, electrical or (electro)magnetic signal which if it is not deactivated, for example taken past an antenna in a shop without being paid for, can cause a signal to be triggered. A security marking of this type is provided with screening that can be deactivated. If it is handled correctly, that is to say deactivated, the effect of the soft magnetic layer used in the security marking can be negated by deactivating it. The optical marking described in European Application 0 673 853 comprises a hologram. Purchasers can see from this hologram whether a product is a genuine brand product or an imitation. According to what is described in the said European Application, the hologram is fixed to the authenticity marking by means of an adhesive. This joining technique, that is to say the use of adhesive, is relatively complex in the case of large-scale production and increases the cost price, but, on the other hand is attractive to imitators. After all, ever increasing numbers of forged holograms are coming onto the market, whilst authenticity markings are likewise being forged. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to provide an improved identification mark which, on the one hand, is less expensive and can be produced more accurately in large runs but, on the other hand, is more difficult to copy. 
     This aim is achieved with an identification mark as described above, and which comprises an authenticity marking provided in the electronically readable marking. The soft magnetic layer has a thickness of less than 1 μm, and an additional metallic layer, which contains the optically readable marking. According to the invention, the hologram or other optical marking is joined to the (acoustic/electro)magnetic marking during the production process itself. By this means an efficient and accurate production process can be provided whilst copying is made more difficult. After all, the identification mark obtained according to the invention no longer consists of the simple combination of a hologram and authenticity marking. In contrast to the European Application 0 673 853 described above, there is no adhesive layer between the hologram component and the (acoustic/electro)magnetic component. 
     It is possible to deposit the additional metallic layer directly on the soft magnetic layer. According to another embodiment, it is possible to insert an intermediate layer, such as a carrier layer consisting of PET, OPP or PVC. The same applies with regard to the optical marking. The latter can either be incorporated directly in the additional metallic layer, but also in a coating applied thereon. The optical marking is preferably a hologram. Holograms are also understood to include kinegrams, pixelgrams, kineforms and the like. These can be either two-dimensional or three-dimensional. Holograms are also understood to include ‘Optical Variable Devices’ (‘OVD’), that is to say devices which are optically readable, for example with the aid of a scanner. Pixel comparison is likewise possible. A hologram can be applied in any way known in the sate of the art. Embossing is one possibility and this is used in particular if the hologram is applied in the additional metallic layer. This additional metallic layer can comprise any material known in the art and according to a preferred embodiment consists of aluminium. 
     The (acoustic/electro)magnetic marking described above can be either an authenticity marking or a security marking. The hologram described above is an authenticity marking. The combination described above of a soft magnetic layer and a (hard) magnetic layer that can be deactivated is a security marking. However, it is possible for the marking according to the invention to be implemented solely as an authenticity marking, that is to say for only a soft magnetic layer to be present which cannot be deactivated in any way whatsoever. So as not to trip existing security devices in such a case, it can be necessary to reduce the effectiveness of such a soft magnetic layer, for example by reducing the thickness thereof. Whereas in the prior art and in the invention the layer thickness of a soft magnetic layer for a security marking is approximately 1 μm, when said marking is used as an authenticity marking said layer thickness will be considerably less than 1 μm and in a preferred embodiment less than 0.5 μm. With the aid of such an (electro)magnetic authenticity marking it is possible to detect markings which are inside packaging, that is to say in situations where the hologram is not visible, with the aid of relatively simple equipment. Moreover, it is possible to give different products different (electro)magnetic characteristics which are characteristic of the products concerned. For instance, the composition of the soft magnetic layer can consist of various quantities and combinations of soft ferrous and non-ferrous metals, such as copper, cobalt, silver and gold. Likewise, a difference in relief, coarser or finer, in the metallic layer and/or the magnetic layer can be produced by using different embossing (hologram, etc.), by means of which the nature of the (electro)magnetic signal is influenced. 
     By means of different combinations it is possible to recognise and distinguish different types of products. It is possible to recognise different products from a distance of, for example, 5 cm using relatively simple equipment. 
     As indicated above, the identification mark can be implemented either as a security marking or as an authenticity marking. It is possible to attach the identification mark according to the invention to packaging, but also to attach it to documents to guarantee the authenticity thereof. The fixing technique can be any technique known in the state of the art, such as sticking. According to an advantageous embodiment of the invention, said fixing technique also comprises the hot stamp technique. With the latter technique fusion takes place between the material to which the identification mark has been applied and that layer of the identification mark which adjoins said material. As a result it is not possible to remove the identification mark without damaging the packaging and/or document concerned. This offers appreciable security. 
     It will be understood that the abovementioned layers of the identification mark are only those layers which are essential to the invention. Depending on the application and the production method, numerous further layers can be present, as will also be seen from the illustrative embodiments described with reference to the drawings. 
     The deposition technique described above for the additional metallic layer, such as an aluminium layer, can comprise any deposition technique known in the state of the art. In this context consideration is given to the vacuum deposition technique, but also to sputtering techniques. 
     It is possible to make the identification mark according to the invention in any shape. For instance, for use on a compact disc the identification mark could be produced in the form of a ring which extends around the central opening. This ring can then be applied either with the aid of an adhesive auxiliary layer or by using the hot stamp technique described above. In the case of use on a compact disc, the identification mark can be either an authenticity marking or a security marking. 
     The present invention also relates to a method for the production of the identification mark described above. With this method the optical marking and the (acoustic/electro)magnetic marking are produced in an unbroken sequence of steps as a single identification mark. That is to say, preferably, after provision of a layer of material having soft magnetic properties, a further metallic layer is applied thereon with the aid of a deposition technique, in which further layer the hologram is then produced. As indicated above, an auxiliary layer, for example composed of plastic material, can have been applied between the soft magnetic layer and the additional layer, which preferably consists of aluminium. Moreover, the additional layer can have been provided with a (plastic) coating in which the hologram is then produced. That is to say, in contrast to the prior art, it is not the case that, on the one hand, an (acoustic/electro)magnetic marking and optical marking are provided in two completely separate steps and these two layers are then joined to one another in a third step, but the hologram or any other optical identification mark is produced in a step integrated in the process in a layer which has already been joined to the soft magnetic layer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in more detail below with reference to illustrative embodiments shown in the drawings. The drawings all refer to an authenticity marking, but it must be understood that the invention also extends to the field of security markings. In the drawings: 
     FIG. 1 shows, in cross-section, one embodiment of the authenticity identification mark according to the invention; 
     FIG. 2 shows a variant of the construction shown in FIG. 1, shown as hot stamping film for hot stamping; 
     FIG. 3 shows the construction according to FIG. 2 after hot stamping; 
     FIG. 4 shows a further film layer that can be processed by the hot stamp technique; 
     FIG. 5 shows laminate using the hot stamp technique, and 
     FIG. 6 shows a further construction in which a paper layer is used as support. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The authenticity marking according to the invention is indicated in its entirety by  1 . The end edges have been shown broken away to indicate that component  1  can have any imaginable shape. This authenticity marking according to the invention consists of a component  2  that has been produced as a hologram or optical authenticity marking and a component  3  in which a magnetisable layer is located. A hologram, as described above, or optical security marking is described in Netherlands Patent Application 9001616. In the embodiment according to FIG. 1, component  2  consists, from the outside to the inside, of a transparent varnish layer  10 , a coating  4  with holographic information incorporated therein, in contact with which there is an aluminium layer  5  which has been produced by vapour deposition on carrier layer  6 , which in this embodiment comprises a PET layer. A magnetisable layer, such as an Atalante® layer  7 , which is provided with an adhesive layer  8  for fixing to the article concerned, adjoins this PET layer. 
     It is possible to produce authenticity marking  1  in any way imaginable in the state of the art. One possibility is to first produce component  3 , after which aluminium layer  5  is vapour-deposited on the PET layer  6 , the layers  4  and  10  then being applied. 
     The various layers can have thicknesses which are suitable for the associated function. 
     For instance, layer  7  can have a thickness of between 0.1 and 0.5 μm and more particularly 0.1-0.5 μm. Layer  4  can have a thickness of approximately 1.0 μm. A thickness of approximately 23 μm may be mentioned for layer  6 . 
     Instead of attaching layer  6  by adhesive, other joining techniques, such as laminating and the like, are also possible. 
     It will be understood that there are equivalents for the various layers. For instance, layer  6  can be replaced by a (biaxially orientated) polypropylene or PVC layer. 
     Those skilled in the art will also understand that component  3  can be replaced by a component reacting to a radio frequency field or by a component reacting to an acoustic-magnetic or electromagnetic field. Adhesion to the authenticity marking  2  will be achieved depending on the component concerned. 
     FIG. 2 shows a film that can be processed by the hot stamp technique and is indicated in its entirety by  11 . This film consists of a polyester layer  12 , a release layer  13 , a varnish layer  14  in which a hologram has been produced with the aid of a relief technique, an aluminium layer  15  applied using a vacuum technique, an additional soft magnetic aluminium layer  16  of relatively small thickness, applied by a sputtering technique, an adhesive layer  17  and a cover layer protecting said adhesive layer. 
     FIG. 3 shows the film  11  after the use of heat and pressure (hot stamp technique). Moreover, the layers  12  and  13  have been removed and the film  11  has been applied to a substrate by removing cover layer  18  and applying a substrate  19 . 
     FIG. 4 shows a further variant in which the film layer is indicated in its entirety by  21 . The polyester layer is indicated by  22  and the underlying release layer by  23 . In contrast to the embodiment according to FIG. 2, the hologram is applied in the aliminium layer indicated by  25 , which aluminium layer has been deposited by a vacuum technique, the hologram facing layer  24  having a relatively small thickness (for example 2 Å). Beneath layer  25  there is once again an additional sputtered soft magnetic layer  26 , a layer of adhesive  27  and a cover layer  28 . FIG. 5 shows how a film  21  is placed between two components of a credit card, which are indicated by  29  and  30 . The film is indicated in its entirety by  31  and consists of a hot-melt adhesive layer  32 , a relatively thick deposited aluminium layer  33 , into which a hologram has been introduced, and a further soft magnetic layer  34 , applied by sputtering, and an adhesive layer  35 . 
     In FIG. 6 a variant of the invention is indicated in its entirety by  41 . This variant is protected by a paper support layer  42  onto which an adhesive  43  has been applied. A polyester layer is indicated by  44 , on which polyester layer a release layer  45  has been applied.  46  indicates a soft magnetic layer applied with the aid of a sputtering technique. An aluminium metallic layer  47 , a varnish layer  48  and a layer  49  containing a hologram have then been applied. An aluminium metallised layer  50  and a sealing layer  51  then follow. The sealing layer  51  can comprise a wax covering. 
     Several of the layers shown in FIG. 6 can be dispensed with or replaced by other layers. For instance, it is possible to apply the hologram in a varnish layer, such as a UV varnish layer. It will be understood that numerous variants are possible which fall within the scope of the present invention but always result in the combination of a hologram with an electronic authenticity marking. 
     Furthermore, it is possible to combine the authenticity marking according to the invention with, for example, a barcode. Such a barcode can be present on the film layer and can be applied, for example, using very fine etching techniques. 
     It will be clear to those skilled in the art that many variants are possible and that the fields of application are likewise diverse. These various aspects fall within the scope of the appended claims.