EP3137313B2 - Security strip and security document incorporating said strip - Google Patents

Description

The present invention relates to a security band intended to be incorporated in part into the structure of a security document at least partially made up of fibers.

It also relates to a security document which is provided with it.

To guard against counterfeiting of security documents, such as banknotes, the use of various security means has already been proposed, such as watermarks, fibers, planks, etc.

Other techniques consist in introducing into the paper of the security document an elongated element of synthetic material forming a strip or security thread which makes it possible to increase the difficulties of making counterfeit products, but also to facilitate the authentication of the document by the central banks when it is equipped with means that can be detected automatically (such as electrical conductivity or magnetism) but also by an ordinary user, in other words the man in the street for so-called first-level visual characteristics.

The integration of this thread or band is carried out at the time of the manufacture of the sheet of paper which will finally form the security document.

This integration can be done in "embedded" form, in which case the thread is completely integrated into the mass of the paper.

It has also been proposed to incorporate the security thread so that it is visible by reflection, only in the form of a set of windows.

This means that this thread is incorporated into the mass of the paper, sometimes flush with the surface of one of the sides of the banknote, which explains the use of the term "window".

Thus, the windows are visible by reflection, while the submerged parts are only visible by transmission. By the term "reflection" is meant the phenomenon by which the rays of incident light are reflected on the surface of the support.

The document US 2008/160226 A1 discloses, for example, a security band emerging from the surface of a security document in the form of a set of windows.

In practice, this integration technique means that the security thread is only visible from the upper side of the paper, and only partially, that is to say at the level of the windows. The present invention aims to fill this gap. It also aims to facilitate the authentication of the security document which incorporates this band, in particular by the man in the street.

Another object is also to make the manufacture of this strip particularly complex, so as to limit and complicate as much as possible the manufacture of strips by unauthorized persons, other than trustee printers. Thus, the present invention, in a first aspect, relates to a security strip intended to be incorporated in part into the structure of a security document at least partially consisting of fibers, this strip emerging on the surface of said document in the form of 'a set of windows, and comprising a transparent or translucent support material, covered, on one or the other of its opposite faces, with at least three distinct and superposed layers of coating.

In accordance with the invention, this band comprises, among these three layers respectively designated first layer, second intermediate layer and third layer, a second intermediate layer which has an optical rendering different from that of the first and third layers. The second intermediate layer is opaque and comprises at least two regions at least partially devoid of coating, these two regions respectively having different contours and the first and third coating layers consist of at least one pattern, a part of the pattern of the first layer being visible through one of said two regions at least partially devoid of coating, while at least part of the pattern of the third layer is visible through the other of said two regions at least partially devoid of coating, said patterns being different from each other.

Thanks to this combination of characteristics, the presence of an opaque intermediate layer makes it possible, on either side of it, to affix additional layers which will be respectively visible from the front face and the back face of the band. Moreover, insofar as the intermediate layer has partially hollowed-out regions of different outlines, the latter will constitute visible additional security signs and the authentication of the headband by the man in the street will be facilitated thereby. And jointly, the task of a fraudster will be made more complex.

Moreover, the fact that part of the pattern of the first layer is visible through one of these regions and that part of the pattern of the third layer is also visible through the other region makes the manufacture of the particularly complex headband, hence greater difficulty for fraudsters to produce the headband according to the invention.

A stencil effect is thus obtained, that is to say a filter effect. In other words, the surfaces of the patterns are "filtered" by the shape of the regions and give different information depending on whether the strip is observed from its front face or its back face. This stencil effect thus generates different but intrinsically linked information.

• lesdits rendus optiques différents sont choisis parmi des couleurs, des brillances, des opacité/transparence et ou des contrastes différent(e)s ;
• lesdites régions sont totalement dépourvues de revêtement ;
• lesdites régions sont partiellement dépourvues de revêtement, et ont la forme d'un réseau tramé ;
• il comporte au moins une quatrième couche additionnelle ;
• ladite quatrième couche est opaque et se superpose à une partie du motif de la troisième couche ; et
• la couche la plus éloignée du support est recouverte d'une couche protective transparente, tel qu'un film ou un vernis.

According to other advantageous and non-limiting characteristics of this headband:

• said different optical renderings are chosen from different colors, brightnesses, opacity/transparency and/or contrasts;
• said regions are totally devoid of coating;
• said regions are partially devoid of coating, and have the form of a raster network;
• it comprises at least one fourth additional layer;
• said fourth layer is opaque and is superimposed on part of the pattern of the third layer; And
• the layer furthest from the support is covered with a transparent protective layer, such as a film or a varnish.

Another aspect of the invention relates to a security document such as a banknote. This is remarkable in that it includes a banner according to one or other of the preceding characteristics, which is incorporated into this document while emerging on the surface of at least one of its visible faces, as a set of windows.

Preferably, the security document is coated locally with a de-opacifying agent, that is to say improving the visibility of the band where it does not emerge on the surface of at least one of the visible faces of the document.

• la figure 1 est une vue de dessus simplifiée d'un document de sécurité, en l'occurrence d'un billet de banque dans lequel est partiellement intégré un bandeau, les motifs de sécurité que comporte ce bandeau n'ayant toutefois pas été représentés ici ;
• la figure 2 est une vue de la face opposée, c'est-à-dire de la face verso du document de la figure 1 ;
• la figure 3 est une vue en coupe transversale et très schématique d'un bandeau conforme à la présente invention ;
• la figure 4A est une vue partielle en perspective avec éclatement de trois couches qui sont intégrées au bandeau selon l'invention ;
• les figures 4B et 4C sont respectivement des vues de face, c'est-à-dire du recto du bandeau, et de la face verso du même bandeau, ces vues étant situées à l'aplomb l'une de l'autre ;
• les figures 5A à 5C, 6A à 6C, 7A à 7C, 8A à 8C, 9A à 9C sont des vues correspondantes aux figures 4A, 4B et 4C selon d'autres modes de réalisation du bandeau.

Other characteristics and advantages of the present invention will appear on reading the following detailed description of some preferred embodiments of the headband. This description will be made with reference to the appended drawings in which:

• there figure 1 is a simplified top view of a security document, in this case a banknote in which a strip is partially integrated, the security patterns that this strip has, however, not having been represented here;
• there picture 2 is a view of the opposite face, i.e. of the back face of the document of the figure 1 ;
• there picture 3 is a very schematic cross-sectional view of a headband according to the present invention;
• there figure 4A is a partial perspective view with explosion of three layers which are integrated into the headband according to the invention;
• THE figures 4B and 4C are respectively front views, that is to say of the front of the headband, and of the back face of the same headband, these views being located plumb with each other;
• THE figures 5A to 5C, 6A to 6C , 7A to 7C, 8A to 8C , 9A to 9C are views corresponding to figures 4A, 4B and 4C according to other embodiments of the headband.

The security document 1 shown in the figures 1 and 2 attached here consists of a banknote.

According to a variant not shown, it could be another type of security document, such as a passport.

This security document is preferably based on cotton paper, with or without chemical pulp, cellulose-based paper or any other material containing fibers of different types and weights, including at least some synthetic fibers. It is also possible to use a hybrid support combining polymer(s) and paper.

As is well known from the prior art, a strip 2 is partially incorporated into the document 1, while emerging at its upper surface corresponding to the front face 10 of the ticket, in the form of a set of windows.

The strip extends along the small transverse dimension of the ticket. The letter P has marked the zones of the band 2 which are integrated into the mass of the banknote and are therefore not completely visible, unlike the window zones F, as shown in the figure 1 .

When we examine the reverse side of this same banknote 1 (see picture 2 ), the presence of the strip 2 is detected, but the latter is completely covered by the fibers of the document, so that it constitutes an assembly N embedded in the mass over its entire longitudinal extent.

By referring to the picture 3 , we are dealing here, in cross section, with the structure of a headband according to the present invention.

However, this representation is made for informational purposes only. Thus in particular, the dimension scales of the various elements that this strip 2 comprises are not respected. All the layers are not represented and appear symbolically in the form of points.

As shown in this figure, the headband according to the invention comprises a support material 4 that is transparent, or at least translucent, such as a plastic film.

It is for example a polyester film having, without limitation, a thickness of approximately 10 to 12 μm.

On the lower face of this support material, that is to say in the direction of the back face 11, there is a thickness 3 of adhesive or of a mixture of adhesives intended to secure the whole of the strip 2 of security with the fibrous material of the document in which it is to be inserted.

Against the second face of the support material 4 there is a stack of layers 5, the nature of which will be described more precisely in relation to the following figures.

A protective layer 6, for example consisting of a plastic film or a varnish, covers the entire stack. Preferably, it is absolutely transparent

In a particular embodiment, the same material as that of the support 4 can be used.

The purpose of this coating is to protect all of the information contained at the level of the layers 5, while allowing their readability.

Finally, the assembly is covered, on the front face side, with another layer 7 of adhesive, preferably of the same nature as layer 3 (but not necessarily).

To the figure 4A and in order to facilitate reading, only the different layers of the stack 5 are shown. From bottom to top, these three layers 51, 52, 53 are superimposed and the first layer 51 is the one which is contiguous to the support material 4.

Only a small fraction of the band 2 has been deliberately shown here, but it is obvious that this band continues on either side of the elements shown here to constitute a piece long enough to be incorporated along the transverse dimension of the security document.

Moreover, with regard to the figures 4B and 4C , there figure 4B represents what is visible on the recto side, that is to say according to a direction of observation which is located from above the layer 53. As for the Fig. 4C , it symbolizes what is visible according to the reverse face of the stack

According to the invention, and in this embodiment, we are dealing with a stack of three layers 51, 52 and 53. For the clarity of the representation, these layers have been represented as being delimited by peripheral lines which form a rectangle . This is however a view of the mind and it should be remembered that only the elements which will be described as being printed or deposited must be considered.

Thus, layer 51 is formed of a set of opaque patterns, for example consisting of a covering black ink printing.

The patterns consist here, for illustrative purposes, of a curvilinear transverse line and whose acronym "FCOF" is printed upside down with the letter "O" full.

The second layer 52, which can be described as intermediate, has an optical rendering different from that of the first layer. By the term "different optical rendering", it is meant that, when these two layers are observed with the naked eye, they can be immediately differentiated from one another, in particular by their color, their shine, their opacity /transparency and/or their different contrast.

A characteristic of intermediate layer 52 is that it is opaque.

Any material having real opacity can be used, and it will be preferred, for example, to form this layer by means of a metallic deposit such as an ink print containing metallic particles with a gold, silver, copper, etc. effect. As a variant, it is possible to proceed with a vacuum deposition of a thin layer of a metal, for example aluminum or opaque copper, then remove this metal locally by washing with soda or water, so as to create zones devoid of coating.

This layer 52 partially covers the first layer 51.

In addition, it is provided with several negative regions 520, which means that they have no coating, these regions respectively having different contours.

In this case, we are dealing here with a first region 520 which consists of a window forming the number “5”, and another region 520 which is constituted by the number “2014”, written upside down.

In this embodiment, it will also be noted the existence of a third region 520′ also formed by the number “5”. We will discuss this later, in more detail.

On this intermediate layer 52 rests a third layer 53 which also has a pattern 530 consisting here of the stylized representation of the letter “O” on the one hand, and in the presence of four squares on the other hand.

Advantageously, but without this constituting an obligation, the materials used for the patterns of layer 51 are the same as those of layer 53.

When we refer to the figure 4B , it can be seen that, by looking at the front side, the four squares of layer 53 completely obscure the region of intermediate layer 52 formed by the number “2014”. On the other hand, the existence of the underlying layer 51 can be discerned through the region 520 consisting of the first digit “5”, which makes this digit “5” legible.

Finally, the additional region 520' is vertical to no print at layer 51.

On the other hand, when one operates an observation by the back face ( Fig. 4C ), that is to say from below the support material 4, one observes through the zone 520 formed by the date "2014", the presence of the underlying layer 53 and in this case small squares which makes the date "2014" legible, while the 520 zone consisting of the number "5" is completely obscured by the "full O" of the acronym "FCOF" drawn in black ink.

From this description, it emerges that the intermediate layer 52 makes it possible to clearly differentiate the layers 51 and 53 from each other, as well as the patterns present therein.

However, the presence of recessed zones, of different shapes at the level of the intermediate layer, reveals according to observations of the front face or the back face, different information but intrinsically linked by their construction, making it possible to authenticate the document of security which is equipped with this blindfold.

By referring to figures 5A to 5C , the nature of the layers 51 and 52 is inverted. It is the same for the layers 52 and 53. Thus, the functionality of this structure is identical to that which appears at the level of the figures 4A to 4C , but the visual rendering is different.

Referring this time to figures 6A to 6C , we note that we are dealing this time with five different layers.

Thus, there is the presence of a first layer 51 comprising patterns 510. On this layer is present an intermediate layer 52 opaque whose some areas 520 are uncoated.

Here again, these areas 520 have different contours.

On this second layer is affixed a third layer 53 which is preferably identical in nature to layer 51. This layer forms patterns referenced 530.

An additional layer that can be described as a fourth layer 54 superimposes the stack 5 of layers 51, 52 and 53. This layer 54 is identical in nature to or different from that of the second layer 52.

In the present case, they are of the same nature.

This fourth layer 54 also exhibits perforated zones since the only region, in which a concealing material is present, is confined here to a circle 540.

Finally, a fifth layer 55 covers the whole. It is preferably of a different nature than the first and third layers. Particularly advantageously, this layer 55 consists of an ink with effects chosen from among the optically variable, iridescent, liquid crystal type so as to create color change effects depending on the angle of observation. This layer can be semi-transparent and comprises patterns 550 which are located directly above patterns 530 and 510 or 540.

According to figure 6B , when the stack 5 is observed from the recto face in reflection, the fifth layer 55 reveals a first piece of information consisting of the patterns 550. The opaque coating of the layer 54 has recessed areas overlapping with the layer 55 and the layer 53 can reveal incidentally, advantageously, another negative message which does not overlap layers 55 and 53.

Coating 53 is only visible from the front face through the recessed areas of layer 54. Conversely, coating 53 is only visible from the back face ( Fig. 6C ) only through the recessed areas of layer 52. The information resulting from the stack 51, 52, 53, 54 and 55 directly above said recessed areas and overlapping layers 52 and 54 is different from an observation in reflection of one of the faces, reciprocally of the other face.

In the example of figures 7A to 7C , the nature of the layers 51 and 52 on the one hand, and 53 and 55 on the other hand, are inverted two by two.

The functionality of such a stack is identical to that of the preceding figures, but the visual rendering is different.

In the embodiment of the figures 8A, 8B and 8C , we are dealing with a first layer 51 consisting of a covering black ink coating.

Furthermore, it will be noted that this black layer occupies only part of the surface of the strip.

On this first layer is deposited a second intermediate layer 52, always formed of an opaque coating, for example of the metallic type, with areas devoid of coating.

More specifically, these are areas 520 which together form the number “2014” and which are produced in the form of a raster network.

This means that there is a multiplicity of recesses in these zones, these being however separated by the constituent material of the covering material.

The shape of the dot and of the raster line as well as its orientation and its coverage are parameters well known to those skilled in the art. By way of example, and without this being limiting, a grid of circular dots of 10 μm is proposed, with a coverage of 50% and an orientation at 45°.

Finally, a third layer is affixed to the second layer 52. It may or may not be identical in nature to that of the layer 51 and, in the present case, they are of the same nature.

By referring to the figure 8B , when the stack is observed from the recto face in reflection, the third layer 53 reveals a first piece of information consisting of the negative patterns 530.

The opaque coating of the metallic type of the second layer 52 offers partially recessed areas overlapping with the first layer 51. The coating of the layer 51 is visible from the front side only through the partially recessed areas of the layer 52 , and, conversely, the coating of layer 53 is visible from the reverse side only through the partially hollowed-out areas of the second layer 52. The information resulting from the stacking of the three layers 51 to 53 plumb partially hollowed out areas of the layer 52 are therefore different from an observation in reflection of one of the faces, reciprocally of the other face, and present a visual rendering, semi-transparent and more nuanced than in the example of the figures 4A to 4C .

Finally, in the embodiment of figures 9A to 9C , we are dealing with the same structure as in the figures which have just been described. Only the nature of the layers 51 and 52 on the one hand, 52 and 53 on the other hand, is inverted. The functionality of the stack thus produced is identical, but the visual rendering is different.

In an exemplary embodiment not shown, the security document in accordance with the invention can be locally coated with a de-opacifying agent, that is to say improving the visibility of the strip 2 where it does not emerge on the surface of at least one of the visible sides of the document, so as to make the information carried by the first layer 51 of the stack 5 more visible.

In yet another exemplary embodiment not shown, at least one of the layers 51, 52, 53, 54 or 55 can incorporate agents that can be authenticated during automatic machine reading. These are, for example, magnetic particles forming a continuous band, blocks or code in the form of bits. They can also be conductive, fluorescent, phosphorescent particles, revealed by infrared radiation or else comprising a specific signal detectable with a dedicated device.

Claims (9)

1. Security strip (2) intended to be incorporated in part into the structure of a security document (1) at least partially consisting of fibers, this strip (2) emerging on the surface of said document in the form of a set of windows (F), and comprising a transparent or translucent carrier material (4), covered, on one or the other of its opposite faces, with at least three separate and superposed coating layers (51, 52, 53), which comprises, among these three layers respectively designated first layer (51), intermediate second layer (52) and third layer (53), an intermediate second layer (52) that has an optical rendering different from that of the first and third layers (51, 53), and in which the intermediate second layer (52) is opaque and has at least two regions (520) at least partially devoid of coating,
   characterized in that said two regions (520) of the intermediate second layer respectively have different outlines, and in that the first and third coating layers (51, 53) consist of at least one pattern (510, 530), a portion of the pattern (510) of the first layer (51) being visible through one of said two regions (520) at least partially devoid of coating, whereas at least a portion of the pattern (530) of the third layer (53) is visible through the other of said two regions (520) at least partially devoid of coating, said patterns (510, 530) being different from each other.
2. Strip according to claim 1, characterized by the fact that said different optical renderings are selected from different colors, sheens, opacity/transparency and/or contrasts.
3. Strip according to one of the preceding claims, characterized by the fact that said regions (520) are completely devoid of coating.
4. Strip according to one of claims 1 or 2, characterized by the fact that said regions (520) are partially devoid of coating, and have the form of a screen network.
5. Strip according to one of the preceding claims, characterized by the fact that it comprises at least a fourth additional layer (54).
6. Strip according to claim 5, characterized by the fact that said fourth layer (54) is opaque and is superposed on a portion of the pattern (530) of the third layer (53).
7. Strip according to one of the preceding claims, characterized by the fact that the layer most distant from the carrier (4) is covered with a transparent protective layer (6), such as a film or a varnish.
8. Security document at least partially consisting of fibers, such as a banknote (1), characterized by the fact that it integrates a strip (2) according to one of the preceding claims, which is incorporated therein while emerging on the surface of at least one of its visible faces (10, 11), in the form of a set of windows (F).
9. Security document according to claim 8, characterized by the fact that it is locally coated with a de-opacifying agent, i.e. an agent that improves the visibility of said strip (2).

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