POSTAGE OR LIKE OFFICIAL STAMPS

Field of the Invention

This invention relates to postage or like official stamps and relates particularly but not exclusively to postage or like official stamps used by national postal authorities or other similar organisations .

Related Applications

This application is based on and claims the benefit of the filing date of US patent application Serial No. 60/742,887 filed 7 December 2005, the contents of which are hereby incorporated by reference in its entirety. That application has been assigned to the applicant company herein.

Background Art

There has been a problem existing for many years with regard to reuse of postage stamps. It is not uncommon for postage stamps to not be cancelled by the postal authority. When cancelling occurs, a cancelling ink is applied over the stamp. Non cancelling can occur for many reasons such as improper registry of any cancelling ink, or two or more postal articles being joined one behind the other so that they appear as a single postal article. In such circumstances, a person can remove an uncancelled stamp from a postal article and reapply the stamp to a new postal article. The stamp is then able to be detected by postal authenticity detection apparatus as a first use stamp even though it may have previously permitted the postage of a postal article.

Further, if a stamp is applied to a postal article and not posted it can then be removed and can then be applied to

another postal article and permit the posting of that article.

US patent specification 5,605,738 is directed to a label that can be applied to an article to detect tampering with the article. A tagging layer is included with the label and the presence of the tagging layer is used by a tagging detection apparatus to determine if there has been tampering with the label on the article. In such case, if the label is removed in order to tamper with the article, then the tagging layer is removed from the article. Thus, the absence of a tagging layer on the article will enable determination that the article may have been tampered with. The disclosure does not relate to stamps. The US patent specification 5,605,738 is totally silent with regard to excluding substantially all the tagging layer from the label portion that is removed.

In International specification WO 02/063595, there is disclosed a postage stamp designed to inhibit against permitted reuse of the stamp. In this disclosure, a tagging layer is provided between a stamp carrier layer that incorporates a stamp image, and an adhesive layer that permits bonding of the stamp to a postal article . It is disclosed that if the postage stamp is removed from a postal article, some of the tagging layer remains with the postal article and some of the tagging layer is removed with the stamp and this permits detection that the stamp is a reused stamp. There is no disclosure that if the stamp is removed from a postal article, that substantially all of the tagging layer should be left behind on the postal article. The disclosure is concerned with the fact that when the reused postage stamp is inspected, the tagging (security indicia) will have been damaged. The document is totally silent about the requirement to leave substantially all of the tagging layer with the postal article to which the stamp was previously adhered to.

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Statements of the Invention

According to a first broad aspect of the invention there is provided a postage or like official stamp having an authenticity tagging layer that is useable for detecting if a stamp is a genuine first use stamp or a reused stamp, said stamp having the authenticity tagging layer being in a layer separate to and under a stamp image carrier layer, said stamp image carrier layer being separable from the stamp after the stamp is applied to a postal or like article, so that the separable stamp image carrier layer will carry substantially none of the authenticity tagging, and so postage authenticity detection apparatus will be able to ascertain that the stamp is a reused stamp by the absence of a tagging layer of sufficient capacity to permit registration detection.

According to another aspect of the present invention there is provided postage stamp having an authenticity tagging layer that is useable for detecting if a stamp is a genuine first use stamp or a reused stamp, said stamp having a first adhesive layer for permitting adhesion of the stamp to a postal article, an authenticity tagging layer over the first adhesive layer, a release adhesive layer over the authenticity tagging layer, and a stamp image carried by a stamp image carrier layer over the release adhesive layer, said stamp image carrier layer having a window to permit the authenticity tagging layer to be detected therethrough by a postal authenticity detection apparatus so the stamp can be detected as a genuine first use stamp, said release adhesive layer being such that if the postage stamp is adhered to a postal article the

release adhesive layer will permit removal of the stamp image carrier layer and the stamp image whilst leaving substantially all of the authenticity tagging layer adhered to the postal article so that if the removed stamp image carrier layer is then applied to another postal article there will be substantially no authenticity tagging layer present, and so postage authenticity detection apparatus will be able to ascertain that the stamp is a reused stamp by the absence of a tagging layer of sufficient capacity to permit registration detection.

According to another aspect of the present invention there is provided a method for permitting detection of a genuine first use postage stamp or a reused postage stamp, said method comprising: i) applying a postage stamp to a postage article, said postage stamp having a first adhesive layer that permits adhesion of the postage stamp to the postage article, an authenticity tagging layer being over the first adhesive layer, a release adhesive layer being over the authenticity tagging layer, a stamp image carrier layer being over the release adhesive layer, said stamp image carrier layer having a stamp image carried thereby, said stamp image carrier layer having a window to permit a postal authenticity detection apparatus to detect the authenticity tagging layer therethrough, and that the stamp is a genuine first use stamp, said release adhesive layer being such that if the stamp carrier layer is removed from the postage article substantially all of the authenticity tagging layer will be left with the postage article, ii) Following removal of the stamp carrier layer from a postage article and the applying of that stamp carrier layer to another postage article, using the postal authenticity detection apparatus to attempt to detect an authenticity tagging layer, and

iii) if no authenticity tagging layer is detected determining that the postage stamp is a reused postage stamp by the absence of a tagging layer of sufficient capacity to permit registration detection by a postal authenticity detection apparatus.

According to another aspect of the present invention there is provided a postage stamp having authenticity tagging useable for detecting if a stamp is a first use stamp, said stamp having a stamp carrier layer carrying a stamp image, a combined adhesive and authenticity tagging layer under the stamp carrier layer and adhered thereto, said stamp carrier layer having a window to permit the authenticity tagging to be detected therethrough by a postal authenticity detection apparatus, the stamp carrier layer having a surface that bonds the combined adhesive and authenticity tagging layer thereto so that when said stamp is applied to a postal article, said stamp carrier layer can be removed from the postal article and leave substantially all of the combined adhesive and authenticity tagging layer with the postal article, so that if the removed stamp carrier layer is then applied to another postal article there will be substantially no authenticity tagging present, and so postage authenticity detection apparatus will be able to ascertain that the stamp is a reused stamp by the absence of tagging of sufficient capacity to permit registration detection.

According to another aspect of the present invention there is provided a method for permitting detection of a genuine first use stamp or a reused postage stamp, said method comprising: i . applying a postage stamp to a postal article,

said postage stamp having a stamp carrier layer carrying a stamp image, a combined adhesive and authenticity tagging layer under the stamp carrier layer and adhered thereto, said combined adhesive and authenticity tagging layer adhering the stamp carrier to the postal article, said stamp carrier layer having a window to permit the authenticity tagging to be detected therethrough by a postal authenticating detection apparatus and determined as a genuine first use stamp, the stamp carrier layer having a surface that bonds the combined adhesive and authenticity tagging layer thereto so said stamp carrier layer can be removed from the postal article and leave substantially all of the combined adhesive and authenticity tagging layer with the postal article, so that if the removed stamp carrier layer is then applied to another postal article there will be substantially no authenticity tagging present, ii. following removal of the stamp carrier layer from a postage article and the applying of that stamp carrier layer to another postage article, using the postal authenticity detection apparatus to attempt to detect an authenticity tagging layer and, iii. determining that the postage stamp is a reused postage stamp by the absence of a tagging layer of sufficient capacity to permit registration detection by a postal authenticity detection apparatus .

Brief Description of the Drawings

In order that the invention can be more clearly ascertained examples of preferred embodiments for use by national postal authorities will now be described with reference to the accompanying drawings wherein:

Figure 1 is an edge on view showing the various layers of a stamp according to a first example,

Figure 2 is a view similar to that of Figure 1 showing a further example,

Figure 3 shows a further example,

Figure 4 shows a still further example,

Figure 5 shows an even further example,

Figure 6 shows an even further example, and

Figure 7 shows an example of an alternative and simplified embodiment.

Detailed Description of Preferred Embodiments

Referring firstly to Figure 1, there is shown a stamp 1 that is to be applied to a postal article 3 such as an envelope. The stamp 1 has an adhesive layer 5, a phosphor tagging layer 7 over the adhesive layer 5, a release adhesive layer 9 over the tagging layer 7, a stamp carrier layer 11 over the release layer 9, and a stamp image in an ink layer 13 over the stamp carrier layer 11.

The adhesive layer 5 may be any known or suitable adhesive layer for bonding a postage stamp to a postal article. Examples of such an adhesive layer are:

1. A peel and stick type adhesive layer used on postage stamps, or

2. A conventional moisture responsive adhesive layer where the stamp is wetted and then applied to the postal article. When the wetted adhesive dries it permits a bond of the stamp to the postal article.

The tagging layer typically comprises a luminescent/phosphorescent tagging medium which allows stamps to be detected by a Culler Facer Canceller machine. Such tagging medium is the principal security feature which authenticates genuine, cancelled/ or counterfeited postage stamps .

The release layer 9 is an adhesive layer that has a lower bonding strength property than in the adhesive layer 5. The release layer 9 may be a dry peelable adhesive or it may be a water soluble adhesive having a lower bonding strength than that of the adhesive in layer 5. Such adhesive can be wetted after drying to allow the stamp to be removed from the postal article. The adhesive layer should ideally be such that when the stamp is peeled or removed there will be no visible damage or adhesive tack.

The stamp carrier layer 11 is typically a transparent film.

The stamp image is applied as an ink image 13 to the carrier layer 11. Figure 1 shows discreet blocks representing parts of the overall ink image 13. It also shows windows 15 between the various parts of the image in the ink image 13 to permit the postal authenticity detection apparatus to view through the ink image 13 and through the transparent carrier layer 11 and through the transparent release layer 9 to view the tagging layer 7.

In the example of Figure 1, the stamp carrier layer 11 and the ink image 13 can be jointly removed from a postal article without any naked eye apparent damage to the stamp carrier and the stamp image (as this is a requirement for philatelists) . This occurs by peeling or soaking the stamp carrier 11 off from the postal article

by separating the stamp carrier layer 11 together with the release layer 9. In this case, the release layer 9 remains with the postal article 3 together with the tagging layer 7 and the adhesive layer 5. Figure 1 shows detail to enable one to determine that when the stamp carrier layer 11 and the ink image 13 are removed from the postal article, substantially all of the tagging layer 7 will be retained on the postal article 3. Thus, if the stamp carrier 11 and the ink image 13 are applied to another postal article there will be no tagging layer 7 present. Thus, when this postal article is introduced to a postal authenticity detection apparatus there can be a determination that the stamp is a reused stamp by the absence of a tagging layer of sufficient capacity to permit registration detection by the postal authenticity detection apparatus. In the case of the example shown in Figure 1 there will be substantially no tagging layer 7 present at all.

The stamp carrier layer 11 is typically a transparent polymer film of 70gsm to lOOgsm and enables windows 13 to be included in the artwork design of the stamp so the postal authenticity detection apparatus can view the underlying tagging in the tagging layer 7. The window 15 may be formed by there being a cut-out, or by there being no printing in the window region, or by the density of any ink in the window region being such that the underlying tagging layer 7 can be suitably detected by the postal authenticity detection apparatus. The density may be controlled by the opacity of the ink, and/or by a stipple or similar arrangement of printing ink. The polymer material can be any suitable polymer material and di-acetate polymers and biaxial orientated polypropylene films are very suitable as they have physical properties ^' similar to paper. Such materials are clear and transparent and have very flat surfaces which also makes them very suitable for use as postage stamp carrier layers

11 .

A stamp of the above type can be produced economically by providing the stamp carrier layer 11 as a large sheet or strip for many stamps, and printing the various underlying and overlying layers thereto by convention printing processes. Thus, stamps of this type can be economically produced in mass numbers.

It can therefore be seen that a postage or like official stamp is provided that has an authenticity tagging layer. The layer can be used for determining if the stamp is a genuine first use stamp or a reused stamp. The authenticity tagging layer 7 is in a layer separate to and under a stamp in carrier layer 11. The carrier layer 11 can be separable from the stamp after the stamp is applied to a postal or like article. When the carrier layer 11 is removed from the postal article by separation from the authenticity tagging layer 7, the carrier layer 11 will carry substantially none of the authenticity tagging layer 7. Thus, if the stamp is to be reused by applying the removed/separated stamp carrier layer 11 to another postal article, the postal authenticity detection apparatus will be able to ascertain that the stamp is a reused stamp by the absence of the tagging layer 7. In some cases, a small amount of tagging layer 7 may be carried with the stamp carrier layer 11. However, there will be an insufficient amount of tagging layer 7 present such that the capacity of that tagging layer will prohibit registration detection by the postage authenticity detection apparatus .

The example shown in Figure 2 is similar to the example shown in Figure 1 and therefore the same layers will not be described again. In this example, the stamp 1 includes a glassine backing 17. The glassine backing 17 is for the case where the stamp is produced as a peel and

stick stamp. Here, the adhesive layer 5 is a suitable peel and stick adhesive layer to permit the peeling off of the overlying layers 7, 9, 11 and 13 as a unitary structure from the glassine backing 17.

Referring now to the example shown in Figure 3, there is a shown a stamp 1 of similar construction to that shown in Figure 1. The various layers are the same as the layers in Figure 1, and for this reason will not be redescribed. The stamp carrier layer 11 however, is a paper or like non transparent film layer. Typically it may comprise a clay coated paper stock of 80gms-100gsm. The stamp carrier 11 has cut windows 19 therein which are in alignment with the windows 15 in the stamp image. Thus, as the stamp carrier 11 is non transparent, the cut windows 19 permit the viewing of the tagging layer 7 by the postal authenticity determining apparatus . The windows 19 may be cut large areas or they may be produced by producing multiple punctures each of relatively smaller area than the area of the windows 19.

The example shown in Figure 4, is of a similar construction to that shown for the example in Figure 1 and the same layers are provided with the same numerical designations. Here, DOVD' s 21 are applied to the stamp carrier 11. DOVD's are known Diffracted Optical Variable Devices that provide a three dimensional holographic image. Such devices are well known and are commonly employed in some countries as part of the normal paper currency of those countries. DOVD' s are typically metallic but enable an image to be viewed in the area of the DOVD' s. Thus, the DOVD' s 21 are applied to the stamp carrier 11 so that they are not covered by the ink image 13. Whilst Figure 4 shows the application of 3 DOVD' s, this is merely diagrammatic. Typically, DOVD' s for a stamp may be a single DOVD device that contains the physical stamp image itself, or some other secondary

authenticating image. The DOVD' s may be applied and adhered to the stamp carrier 11 by any suitable adhesive material. In a variation, the DOVD may be a single DOVD over the whole of the stamp area and there may not be any ink image 13 applied to the stamp 1. Thus, the DOVD may be applied to indicate both the stamp image itself and the monetary value of the stamp itself. In a further variation, the DOVD may be provided in a layer which substitutes for the carrier layer 11. Thus, in this variation, the DOVD is the stamp carrier layer itself. A window 19 may be provided at one or more locations (not shown to aid clarity of Figure 4) , to permit viewing of the underlying tagging layer 7. If the stamp carrier 11 is non transparent then the window (19) may be cut out from the stamp carrier 11, or be multiple punctures as discussed previously.

Figure 5 shows a further example where the tagging layer 7 is incorporated into the adhesive layer 5 as a composite of tagging and adhesive. The release layer 9 is an adhesive that enables peeling off or dissolving off of the stamp carrier 11 whilst leaving the combined tagging and adhesive layer 23 retained to the postal article. Thus, the release layer 9 will have a lower bonding strength to the carrier layer 11 than the bonding strength of the combined tagging and adhesive layer 23 to the postal article 3. A window 19 may be provided at one or more locations, to permit viewing of the underlying tagging layer 7. If the stamp carrier 11 is non transparent then the window (19) may be cut out from the stamp carrier 11, or be multiple punctures as described previously.

Referring to the example shown in 6, it is similar to the example shown in Figure 4. In this example, a diffraction grating 25 is provided over the stamp carrier 11. The diffraction grating provides a

Diffraction Optical Effect like a lenticular lens and can be configured to provide a particular identifying image which can enable a person to visually determine authenticity of the particular stamp. The Diffraction Optical Effect can be provided in a separate layer to the stamp carrier layer 11 or alternatively it may form an integral part of the stamp carrier layer 11. A window 19 may be provided at one or more locations (not shown to aid clarity of Figure 6) , to permit viewing of the underlying tagging layer 7. If the stamp carrier 11 is non transparent then the window (19) may be cut from the stamp carrier 11 as described previously.

Figure 7 shows an example using a lenticular lens as the stamp carrier layer 11. The stamp image 13 is printed on the under surface of the lenticular lens. A combined tagging and adhesive layer 23 is printed or otherwise applied to the stamp image 13. The combined tagging and adhesive layer 23 may have a preferential bonding to the postal article 3 relative to the stamp image 13. The surface coatings of the postal article 3 and the stamp image 13 will be chosen such that the lenticular lens 11 with the stamp image 13 attached can be either peeled off or dissolved off from the combined tagging and adhesive layer 23 whilst leaving substantially all of the combined tagging and adhesive layer 23 retained on the postal article 3. Whilst this embodiment shows that a combined tagging and adhesive layer 23 is utilised, the tagging may be in a separate independent layer to the adhesive. In this case, the tagging layer would be applied in such a way that when the lenticular lens 11 and the stamp image 13 are removed by either peeling off or dissolving off, substantially all of the tagging layer will remain attached to the postal article 3. A window 19 may be provided at one or more locations (not shown to aid clarity of Figure 7) , to permit viewing of the underlying tagging layer 7. If the stamp carrier 11 is non

transparent then the window (19) may be cut from the stamp carrier 11 as described previously.

Figure 8 shows a further example having a combined tagging and adhesive layer 23 that may have a preferential bonding to the postal article relative to the stamp carrier 11. Thus, in this case, the release layer 9 may be dispensed with. The surface coatings of the postal article and the stamp carrier 11 will be chosen such that the stamp carrier 11 can be peeled off or dissolved off from the combined tagging and adhesive layer 23 whilst leaving substantially all of the combined tagging and adhesive layer 23 retained on the postal article 3. In such case, a small proportion of the combined tagging and adhesive material in the layer 23 may still then be retained to the under surface of the stamp carrier 11 but the proportion will be very small relative to that remaining on the postal article 3. If any such tagging carries with the stamp carrier 11, then it will be of insufficient capacity to permit registration detection by a postal authority detection apparatus . A window 19 may be provided at one or more locations (not shown to aid clarity of Figure 8) , to permit viewing of the underlying tagging layer 7. If the stamp carrier 11 is non transparent then the window (19) may be cut from the stamp carrier 11 as described previously.

Throughout all the embodiments the windows, being either the windows 15 or windows 19, need to be sufficient to permit the underlying tagging to be detected. Thus, the density of the tagging 7 and the physical size of the windows 15, 19 need to be controlled to jointly provide for sufficient response for the postal authenticity detection apparatus to detect the presence of the tagging when the stamp 1 is applied as a first use stamp to a postal article.

Throughout the embodiments the stamp itself has

an optical or machine readable window to allow the authentication layer being the tagging layer 7 to be viewed through the postage stamp. In some cases, the stamp carrier material is transparent and in such cases the window is an area of the stamp carrier material through which the underlying tagging layer can be viewed. In other cases, where the stamp carrier material is not transparent then the windows are cut into that carrier material to permit viewing of the underlaying tagging layer. If required, the window area could be arranged for one way viewing. In other words, the window may be arranged to allow a tagging signal to be emitted from the back of the stamp through that window but not enabling the tagging layer itself to be directly viewed by an unaided human eye.

It can be appreciated that security features can be incorporated into the stamp carrier material and/or the windows . Such security features provide optical and machine readable features that contribute to the ability of the postal authority to prevent reuse, counterfeiting and forgery of postage stamps .

Throughout the examples, the adhesive layers, being either the layer 5 or the layer 9, are chosen to provide a preferential bonding to the postal article so that upon subsequent peeling off or soaking off of the stamp carrier 11, the tagging will remain primarily with the postal article 3 and not be carried with the stamp carrier 11. Thus, the various tack and surface smoothness characteristics at the interfaces of the layers need to be appropriately chosen to provide for this preferential separation.

Suitable materials for the stamp carrier 11 are di-acetate film, ethylene vinyl acetate films (EVA) , that have a surface energy of 40 to 42 Dynes, or clay coated

paper stocks that have a smoothness greater than 1000 Bekk Sec.

In the case where a water soluble adhesive layer is provided it may comprise vegetable based, polyvinyl acetate emulsions and dispersions (PVAc) or polyvinyl alcohols (PVOH) . In the case where a dry bond adhesive layer is required the adhesive may comprise vegetable based polyvinyl emulsions and dispersions (PVAc) or polyvinyl alcohols (PVOH) .

It should be appreciated that the examples are specifically for postage stamps for use by national postal authorities, however, the same teachings may be extended to labels or other like official stamp attachments for other authentication needs, and that the invention is not to be limited to postage stamps per se.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Modifications may be made to the examples as would be determinable by persons possessing knowledge of the arts of postage stamps. For example, by coating the release layer 9 to the under surface of the carrier layer

11 as a separate step during manufacture, it may be possible to provide the cut-out windows 19 free of any release layer 9. In such case the release layer 9 need not be transparent, as the postal authentication detection apparatus will be able to view through the windows 19 and view any tagging.

These are other modifications may be made without departing from the ambit of the invention the nature of which is to be determined from the foregoing description.