KR20180002615A - Security Elements and Secure Documents - Google Patents

Abstract

The present invention relates to a security element (20) for a secure document (10). The security element comprises a first perforated layer (24) made of a first material and defining at least one half-tone raster pattern, and a second perforated layer (24) made of a second material different from the first material, And a second layer which is adapted to be able to receive the radiation.

Description

Security Elements and Secure Documents

The present invention relates to security elements used in security documents and security documents.

For example, paper and integrated liners, or security foils, including banknotes, which include roughly broad bands, and checks, credentials, identification cards, credit cards or warranty cards Other security documents have been circulating for many years and are widely used in many countries.

The hidden lines in these documents are in some cases exposed to visible light in reflected light in pre-compartmentalized areas that are present on at least one side of the documents, and these areas are usually named "windows ".

Hidden lines make it more difficult to imitate security documents. They contribute to the authentication of documents by showing different shapes to them in transmitted light and reflected light in general.

Methods of making paper with silver halide integrated in windows are known from patent applications EP 0059056, WO 93/08327 and WO 03/095188.

In addition, manufacturers of hidden lines want to make them with level 1 security, which makes it difficult to replicate counterfeit goods while being easily identifiable by people on the street.

When documents are viewed in transmitted light, hidden lines are traditionally made of zones that produce patterns in transmitted light, due to the presence of the metal layer with recesses through which light passes.

EP 1 674 286 A1 relates to a security element for reproducing an object with the aid of an image formed by dots. This document discloses that an image can be formed by various layers with different optical densities.

WO 99/04983 describes a security element comprising a semi-reflective layer covering the magnet layer.

WO 2007/020370 A2 discloses hidden lines which are formed by fine patterns, respectively, and which contain visible patterns.

EP 0 659 587 A1, EP 0 319 157 A2, WO 2007/141459 A2 and WO 2013/160880 A2 disclose other security factors.

EP 0 998 396 B2 discloses a security element with different optical densities, for example, one opaque layer with a transfer rate of up to 30% and a smaller opaque layer with a transfer rate of at least 50%. The two layers may be made of the same metal or different metals. In one example, the security element comprises a magnet layer, which may include, for example, recesses in the form of letters. The magnet layer is covered by a semi-transparent layer in the form of a raster. Therefore, the semi-transparent layer hides the magnet layer. In one example, the security element has a backing that includes two identical layers each in the form of a rectangular raster on opposite sides thereof. Further, the non-perforated layer is present on any of the surfaces between the backing and the semi-transparent layer.

EP 1 503 903 B1 discloses a security with a backing covering a second perforated layer made of a second metal, such as copper, made of a first metal, such as aluminum, covered on one side by a first perforated layer Element. The thickness of the metal of the second layer is sufficiently thin such that this layer is semi-transparent. The first and second layers have first openings coinciding with each other and the first layer has a second opening exiting toward the rigid portion of the second layer. Therefore, in the transmitted light, the observer can perceive the outline of the first apertures through a slight difference in hue within the region of the zone having the apertures by passage of light through one of them in the second layer. In reflected light, the observer perceives the difference in color of the two metals within the region of the first and second openings in the first layer. In another example, the backing includes two overlapping layers on one side, each one having recesses in the form of alphanumeric characters. Within certain zones, the hard parts of the two layers are superimposed exactly.

The present invention aims at providing security elements, particularly hidden lines, for improved security documents.

In order to achieve the above object, according to one aspect, a security element for a security document comprises a perforated first layer made of a first material and defining at least one half-tone raster pattern, Transparent second layer that is made to be visible through at least one opening in the first layer.

The present invention constitutes a level 1 security, making the embedding material more difficult and achieving attractive optical effects for viewers.

"Semi-transparent layer" refers to a transparent layer that appears opaque when viewed in reflected light and visible when viewed in transmitted light.

Preferably, the second semi-transparent layer is also semi-reflective. "Semi-reflective" means a reflective layer, which is transparent when viewed in reflected light at a second angle of observation or illumination, specifically with specular reflection when viewed in reflected light at a first angle of observation or illumination .

The second semi-transparent layer may appear opaque when viewed in reflected light, regardless of the angle of observation or illumination.

In particular, the second layer can, if necessary, create a background of a color different from that of the material of the first layer in the reflected light, without unduly interfering with the observation of the half-tone raster pattern in the transmitted light.

Preferably, the first material is metallic, more preferably a metal. Also preferably, the second material is also such. For example, metals with different colors can be selected, such as copper and aluminum, or alloys thereof.

Advantageously, the second layer has a semi-transparent raster which is semi-transparent. In this case, the thickness of the metal of the lines or dots of the raster may be large enough so that the layer is locally opaque where metal is present.

The use of raster gives additional possibilities in relation to the generation of patterns. In particular, as will be described further below, the dots and lines of the raster may be formed by basic patterns that allow for a degree of additional protection.

The second layer may specifically include one or more macro-recesses in the form of alphanumeric characters or an opening with the same contour as the half-tone raster pattern of the first layer. As a variant, the second layer has an outline corresponding to that of the half-tone raster pattern, and the two are arranged to overlap exactly.

In a first material, a layer of a first metal may define at least one half-tone pattern and one alphanumeric pattern.

The raster of the second layer is preferably homogeneous and preferably has repeating parallel lines. The compactness of the lines and their proximity to each other can be as much as 10 cm, for example, to the extent that the observer can not easily distinguish them individually by the naked eye. For example, the lines are separated by a width of less than 25 占 퐉, for example, on the order of 20 占 퐉, and a distance of 40 占 퐉 to 60 占 퐉, for example, on the order of 50 占 퐉.

As a variant, the second material In particular, the raster of the layer of the second metal is formed by basic patterns such as dots or letters, numbers, or symbols, the height is preferably 100 占 퐉 or less, Lt; RTI ID = 0.0 > um, < / RTI > Thus, for example, at a distance of 10 cm, it is possible to form a homogeneous figure in the raster formed by similar, parallel lines, visually.

The raster can be interrupted elsewhere to define at least one pattern specifically, a fine pattern, preferably an alphanumeric pattern, within the second material, specifically the layer of the second metal.

In a first material, a layer of a first metal may define a first pattern of positive or negative alphanumerics.

The second material layer can define a second pattern of positive or negative alphanumerics. The second pattern may, for example, contain the same information as the first pattern, indicating the same number, the same word, or the same meaning.

The first material In particular, the pattern or patterns within the layer of the first metal may comprise one or more patterns in the form of dots or sets of symbols.

The first material, in particular, the pattern or patterns present within the layer of the first metal may be arranged in a manner such that the second material is specifically associated with the pattern (s) present within the layer of the second metal. That is, the relative positions of the patterns of the two layers may be constant over the entire length of the element during its fabrication.

The first material In particular, the pattern or patterns formed within the layer of the first metal may be visually independent from the pattern or patterns formed within the second material, specifically the layer of the second metal. That is, the respective patterns of the layers need not complement each other to take their full meaning in the eyes of the observer in transmitted light and / or reflected light.

As a variant, at least one pattern of the first layer and at least one pattern of the second layer complement each other in transmitted and / or reflected light. For example, these patterns reconstruct objects, numbers, or words. For example, one of the patterns forms the face of the person and the other pattern forms the human hair. This enables multichrome representations of attractive objects, especially in reflected light.

The patterns complementary to each other may have positive or negative solid lines, respectively. Also, in one of them, they may have only one solid line, positive or negative, and in the other case, a half-tone image. As a further alternative, each of the two complementary patterns may reproduce a half-toned image, and each may optionally comprise one or more solid lines of positive or negative.

The patterns formed by the layers of first and second metals may be geometrically connected or may comprise the same object, such as an object or organism, and in particular they may facilitate comparison because they may be identical. For example, they may represent the same symbol or image, but may be of different size, one positive and the other negative.

The first material In particular, the layer of the first metal may extend over the entire surface of the backing, except for the openings of the patterns. The second material In particular, the layer of the second metal may extend over the entire surface of the backing except for the opening of the patterns. In particular, the width of the layers of the first and / or second materials may correspond to that of knocking. As a variant, it can be smaller.

One of the layers may define an isolated pattern, specifically a visible pattern, and the other layer may have a primary repeating pattern, specifically a fine pattern.

The isolated pattern can be represented in a half-tone, in particular, a raster representing objects that are provided with shadow effects due to raster and viewed by perspective. Therefore, a relief effect based on a binary raster can be obtained.

The primary pattern can be an alphanumeric or symbolic representation.

In one embodiment, the first layer and the second layer are patterned to complement each other in the openings. Specifically, patterns formed at least partially in half-tone respectively, preferably upwardly along the security element, This downwardly partitioned patterns are arranged in a shop.

For example, each of these patterns is formed by a half-tone raster. The second layer represents a semi-transparent raster covering only one of the two patterns of the first layer so that in the reflected light one of the patterns overlaps with the raster of the second layer, And gives a multicolor appearance for the surface of the object, the two patterns of the first layer represent different shapes. In other words, in the transmitted light, the shapes of the patterns are monochromatic.

The security element may constitute a hidden line or security film.

The present invention according to another aspect provides a security element for a security document, either independently or in combination with the invention according to the above aspects, wherein the security element comprises a backing, a first perforation layer made of a first material on one side of the backing, And a second layer made of a second material different from the first material and having a semi-transparent raster visible through at least one opening in the first layer, the second layer lying between the surface of the backing and the first layer.

According to another aspect, the invention provides a security element, independently or in combination with the above aspects, which security element comprises a backing having at least one transparent area, on the area, an optical density DO1 A layer of a first metal and a layer of a second metal different from the first metal with an optical density of D2, wherein | DO2-DO1 | <1, more preferably | DO2-DO1 | <5.

The optical density (DO) is given by DO = -log T, where T is the measured transmission rate according to standard ISO 15368.

The security element according to the last aspect of the present invention can provide level 1 security, which is easily recognizable by a person at a distance, while mocking is still difficult. In particular, the layers of metal can constitute a level 3 security that allows for confirmation of whether their optical densities are predictive and sufficiently similar.

In all processes, the backing is preferably a foil of a thermoplastic transparent material.

First and second materials In particular, the layers of metals may be placed on opposite sides of the backing or on the same side of the backing, and may at least partially, preferably not completely, be overlapped. The first material layer is preferably a pattern shape that can be seen from the front in the reflected light and visually or magnified. Preferably, the layer of the first metal preferably has a half-tone image and an alphanumeric pattern of first information &Lt; / RTI &gt;

The layer of the first material is preferably opaque and in particular has an optical density greater than 0.8 in consideration of the hard surfaces of the layer, i.e. without openings.

Secondary material In particular, the layer of the second metal can be, for example, in the form of a pattern that can be recognized visually or magnified, preferably in the form of a microscopic pattern, in particular in the form of alphanumeric patterns, And a second information item.

The two parts of this information preferably remain similar in reflected light, in the presence of the relative transparency of the security elements forming the whole.

The presence of an information item on one of the two layers can be used to provide a level 2 security that will enhance, for example, the second material, specifically the fine raster of the layer of the second metal, and / Microscopic patterns, such as expression patterns, can only be seen through enlargement.

The invention also relates to a security document comprising a security element according to any one of the above-mentioned aspects of the invention.

The patterns of the layers of metal may be formed by any method including metallization and / or demetallization of the backing, i. E. At least one step of metallization or demetallization of the backing. In particular, it may comprise a process of selective metallization or a process of selective metallization followed by demetallization. Preferably, it comprises a process of selective metallization of the backing followed by demetallization. As a variant, at least one of the layers of the first and second metals is deposited by printing.

&Quot; Selective metallization "or" selective demetallization "means metallization or demetallization, respectively, which is not generic, that is, is not done over the entire surface of the backing, In vacuum or electrochemically.

"Layer of metal" means a layer of one or more metals used alone or in the form of an alloy. The metal of each layer is selected, for example, from metals Al, Cr, Ni, Ag, Au, Cu, and Sn, which are commonly experienced in the silver wire field.

The first metal, or vice versa, is preferably selected from Ag, Al, Sn and alloys thereof. The second metal, or conversely the first metal, is preferably selected from Cu, Au, Zn and their alloys.

The first metal may be colorless. That is, the first metal may exhibit a substantially homogeneous absorbency in the visible spectrum which is substantially homogeneous. The second metal may exhibit a color such as golden or copper. The opposite is also possible. According to one variant, the first metal is a hologram or an interference structure, in particular a multi-layer structure, or it functions as a reflection layer in a structure which exhibits a change in color ("color change") as the viewing angle changes.

The metals used can all be non-magnetic. As a variant, at least one of them is magnetic.

When the security element according to the present invention forms a hidden line, for example, its width is in the range of 0.5 mm to 15 mm, preferably 3 mm to 8 mm.

Since the thickness of the first or second metal layer is preferably sufficiently thin, the layer is semi-transparent and has an optical density of less than or equal to 0.8.

For example, in the case of the metals in Table 1 below, examples corresponding to values with such optical densities of 0.8 or less are given.

Thickness (nm) Al 15 Cu 15 AlCu 15

The optical densities of the layers of the first and second metals are such that if there are no openings, i. E. Considering the respective hard surfaces of these layers, the security element may not be opaque in transmitted light, And may preferably be 0.8 or less.

According to a preferred variant, the first metal is opaque and the second metal is semi-transparent.

The first and / or second metal may directly contact the backing or, alternatively, it may cover at least the intermediate layer in contact with the backing. For example, the layer is used to enable selective metallization and / or demetallization of the backing.

Refers to any pattern that can visually identify one or more alphanumeric characters or images of objects such as a person, animal, object, landscape, plant, or monument. The half-tone pattern means a pattern that preferably appears in 3D due to the shadow effect obtained by the half-tone reproduction of the shadows. Hidden lines with half-tone raster patterns were proposed by a patent applicant under the Picture Thread ™ title.

The pattern may be formed with a plurality of apertures of the same size or variability size.

The first material, specifically the first metal, or the second material. Specifically, the pattern present on the layer of the second metal may be present at any location on the security document in the form of, for example, a watermark or imprint . For example, the value of the paper money appears simultaneously on the layer of the first and / or second metal and in the form of a transfer on the substrate of the document.

Further, the present invention relates to a security element, independently or in combination with the above aspects.

The security element includes a backing, a layer of a first metal, and a layer of a second metal that is different from the first metal and at least partially overlies the layer of the first metal, And the second metal layer has a raster and is preferably semi-transparent.

Preferably, the layer of second metal is formed with openings that define each of the second patterns, the second patterns are smaller in size than that of the first pattern, and the second patterns are at least partially Overlapping.

The second patterns are preferably micro-scopic patterns that can be formed by interrupts in the raster.

The first pattern and the second pattern may represent the same word or number.

Also, the first layer can define a half-tone pattern.

The invention will be better understood when the following detailed description of the non-limiting embodiments is read in conjunction with the accompanying drawings.
1 shows a front view of an example of a secure document according to the present invention.
Figure 2 shows a schematic longitudinal cross-sectional view of a security element according to the invention.
Figure 3 shows a view from the front of the security element of Figure 2;
Figure 4 shows a view from the back of the security element of Figure 2;
Figures 5 and 6 show detail views of Figures 3 and 4, respectively.
Figures 7 and 8 are views similar to Figures 3 and 4 of an alternative embodiment of a security element.
Figs. 9 and 10 show the detailed views of Figs. 7 and 8, respectively.
Figs. 11 to 13 are views similar to Fig. 2 of the modified embodiments.
14 is an example of a half-tone raster pattern made in the first layer of a security element in a variation.
Fig. 15 is an example of a semi-transparent raster formed by the second layer and constituting an isolated pattern designed to overlap on one of the half-tone patterns illustrated in Fig.
Fig. 16 shows a security element formed by overlapping the patterns of Figs. 14 and 15 in reflected light.
Fig. 17 shows a modification of the security element.

In the drawings, the different elements have not necessarily been referred to as being in contact with one another or in their actual proportions in order to more clearly illustrate the figures.

Optional additional layers such as adhesives or protective layers are not shown.

1 shows a security document 10 provided with a security element 20 according to the present invention.

The security document 10 is for example a bank note and preferably comprises a fibrous base material 11 and the security element 20 may for example comprise a base material 11 extending from one edge of the base material 11 to another edge, It exists in the form of silver lines.

In one variant, the substrate 11 of the document is a polymeric substrate or a paper-polymer hybrid substrate and the security element can be a polymeric substrate surface in the form of a band, for example, Lt; / RTI &gt;

As shown in FIG. 1, the hidden line 20 is introduced into the windows, with a face visible in the reflected light passing through the window 12 of the substrate 11.

The length L of the window 12 measured parallel to the longitudinal axis of the element 20 is preferably at least 5 mm, or preferably at least 10 mm.

The width 1 of the element 20 is in the range of, for example, 0.5 mm to 15 mm, or preferably 4 mm to 8 mm.

As shown in FIG. 2, the security element 20 preferably includes a backing 22, such as polyester, made of a transparent plastic material.

The thickness (e) of the backing may be in the range of 6 탆 to 60 탆.

In the example of Figure 2 the backing 22 is formed by a layer of first metal 24 on one side 23 and by a layer 26 of a second metal different from the first metal on the opposite side 25 .

Layer 24 of the first metal may have an optical density DO1 and layer 26 of the second metal may have an optical density DO2. The two optical densities DO1 and DO2 are preferably close to each other, such as | DO2-DO1 | < 1.

The optical density (DO) of a layer of metal is given by the relationship DO = -logT, where T is the transmission rate measured according to standard ISO 15368, as described above.

The measurement takes into account the raster. The first layer may be opaque and the rasterized second layer may be semi-transparent so that the pattern of the first layer remains visible when viewed in transmitted light.

Preferably, the first metal functions as a reflective layer in a structure that is achromatic, holographic, and has an interference structure specifically a multi-layer structure, or a "color change" effect, while a second metal may have a color, It is also possible.

The first metal may be aluminum and the second metal may be copper or copper alloy with copper light or golden color, and vice versa. Preferably, the layer of the second metal and the layer of the second metal are perforated to compartmentalize visible and / or magnified patterns in the reflected and / or transmitted light, respectively. Also, at least one of the layers 24, 26 is perforated to form a raster.

The openings 28 formed in the first metal layer 24 are represented very schematically in Figure 2, like the openings 29 formed in the layer 26 of the second metal, Can be changed as a function of the appearance to be formed in the security element.

Referring to Figures 3-6, a first exemplary embodiment of a security element is described.

In this example, a layer of second metal 24 appears at the front of the security element and a layer 26 of the second metal appears at the back of the security element. The security element 10 may be designed to allow observation in reflected light only at the front of the security element. Or, as a variant, for example, observations of both the front and back of the security element may be allowed by virtue of the presence of front or rear windows or penetrating windows of the description of the document.

In Figure 3, the layer 24 may be made of openings in the form of alphanumeric patterns 30, such as, for example, the numeral 100, and these patterns 30 may be made upside- To the front.

The alphanumeric pattern or patterns 30 have a sufficient size, for example visible to the naked eye, and have a height of, for example, at least 1.2 mm.

In addition, visible patterns 31 in the form of visible images that reproduce the shadow effect can be created within the layer 24.

In the example considered, the dot 32 has, for example, a polygonal shape and the raster is of amplitude-modulated type, that is, the step where the dots are arranged is rectangular, but the size of the dots changes. As a variant, the raster may be of the frequency modulation type. Dots can have very different shapes.

In addition, the pattern 31 may have zones 33, for example, represented by solid lines to indicate nose or eyes.

Reference may be made to EP 1 674 286 A1, which discloses the manufacture of raster images which impress relief.

Advantageously, the security element 20 is implemented such that the alphanumeric patterns 30 and the half-tone patterns 31 are alternately shown in the longitudinal direction.

Referring to Figs. 4 and 6, the second metal layer 26 has, for example, fine rasters 34 arranged at regular intervals and interrupted to form patterns 35. [ Preferably, these patterns 35 are repeated and represent the number 100.

Preferably, the size of the pattern 35 is smaller than that of the pattern 30. The raster formed by the lines 34 may look homogeneous if the lines 34 are sufficiently thin and close to each other.

Preferably, as shown in Figure 6, the width d of the raster lines 34 is between 20 μm and 25 μm, for example, the spacing t between two adjacent rasters 34 is And is between 40 μm and 60 μm.

For example, the lines 34 have a width of 20 m and the spacing t therebetween is 50 m. The lines 34 may be oriented obliquely with respect to the longitudinal axis of the backing 22. As shown, the lines 34 may be straight. As a variant, these lines 34 may be curved, specifically, in height.

Preferably, the number of lines per inch (lpi) 34 is greater than or equal to 800, preferably 2000, so that any attempt to copy these lines with the help of conventional presses whose resolution is less than this can be avoided.

The patterns 35 are preferably observable by eye or by magnification.

The height of the figures of the patterns 35 is, for example, 100 mu m.

In the example of FIG. 4, the patterns 35 are written from the back to the top down so that the top side appears upwards.

In particular, from the comparison of FIGS. 3 and 4, the patterns 35 may appear inside the openings in the patterns 30, 31 formed in the layer 24.

Similarly, when the layer 24 can pass through the patterns 35 and appear in the reflected light, and the security element 20 is observable in the reflected light from behind, the patterns 35 are solidified in the metallization of the layer 24 Lt; / RTI &gt;

Where the patterns 35 overlap with the openings of the patterns 30, 31, the observer can see through the backing 32 of the security element, specifically, in transmitted light.

3 to 6, the opacity of the layer 24 is such that the patterns formed in the layer 26 are patterned in the patterns 30 and 31 of the layer 24 when the security element 20 is viewed in the reflected light from the front side. Lt; RTI ID = 0.0 &gt; of the openings of &lt; / RTI &gt;

4, when the security element 20 is viewed from behind, if the security document is thus allowed by discontinuity due to the presence of the raster lines 34, in the reflected light, the solids of the layer 24 The second layer of metal 26 can be recognized as a substantially uniform color by the observer. This gives the security element a special color on the back side, in addition to the area of the patterns 35, thanks to the overlap of the raster lines 34 and the layer 24. [

By adjusting the ratio of the surface occupied by the raster lines to the unoccupied surface, it is possible to change the apparent hue of the layer 26 in the rasterized zone between the second metal pure color and that of the first metal.

Because there is no such region of the first metal layer 24, the color of the layer 26 appears different in the region of the openings of the patterns 30, 31.

Therefore, considering the fact that the raster lines 34 can be reproduced with a very high density and have an attractive effect to the observer, various hue nuances can be obtained in the reflected light which are difficult to duplicate.

The presence of such color nuances based on metal coatings constitutes complementary security.

Preferably, the surface conditions of the layers 24, 26 are such that they produce specific metallic reflections on their surface.

Complementary optical effects can be obtained, for example, by adjusting this surface state, such as creating micro-reliefs in certain zones.

In the examples of Figures 7 to 10, the layer 24 of the first metal replicates the same patterns 30 and 31 as the example of Figure 3. The second layer of metal 26, seen from the rear, has parallel raster lines 34, as described above. In other words, these raster lines 34 define patterns 40 that are the same size as those of patterns 30.

Again, one tone corresponds to a superposition of layer 24 and raster lines 34 and the other tone corresponds to the overlap of the lines 34 with the openings of patterns 30 or 31, Can be obtained in the region of metallic color.

Of course, the invention is not limited to the examples described.

In particular, instead of disposing the layers 24 and 26 on one side of the backing 22 as shown in Fig. 11, they may be placed on the same side.

12 illustrates the possibility of layers 24 and 26 of first and second metals that are not fully overlapped.

In the example of Figure 12, the layers 24, 26 overlap only within one zone 50, such as the central zone of the security element.

13, the layers 24, 26 are not laid on the same side of the backing 22, but on the opposite sides, as in Fig.

In the example of FIGS. 14-16, the first layer 24 has a half-tone raster pattern superimposed on the isolated pattern 70 of the same outline of the second layer.

The layer 26 of rasters of the second metal seen in the apertures of the half-tone raster pattern changes the visibility of the details of the detail in the reflected light. Therefore, this pattern becomes visible in the reflected light using a reflective background having the color of the second metal.

Since the other half-tone raster patterns of FIG. 16 do not overlap on the pattern 70 of the second layer, when viewed in reflected light, this means that the half-tone raster pattern has an image with a relief effect on a transparent background, , With the help of a relief effect on the reflective background, it gives another image of the same object. The two patterns can be seen by observation in transmitted light.

17 shows that the first layer 24 represents the first apertures 128a for representing the first pattern, in this case the face, in the reflected light and the second apertures 128b in alphanumeric form, And a security document 20 that represents a number corresponding to the face value.

The patterns of the openings 128b are alternately arranged, as illustrated, such that when moving along the security element, the top side goes up and the bottom side goes down. The same principle applies to the patterns of the openings 128a. This makes it possible to observe both upward and downward in the front and back of the element 20 in the reflected light.

For example, the layer 24 of the first metal is aluminum. The pattern formed in the openings 128a may be a half-tone pattern to reproduce the shadow effect.

Similarly, the element 20 has a layer 26 of a second metal different from the first metal, such as copper or a copper alloy. This second layer 26 is semi-transparent, for example due to the thickness of the metal.

The second layer 26 can be seen in the reflected light in the openings 128b, on the one hand, forming the patterns 140 reproducing their meaning, in this case the same numbers formed by the openings 128b .

Intervals 141 may exist between the layers 24, 26 within the openings 128b.

Within the openings 128a, the second layer 26 forms patterns 142 that complement the patterns formed by the first layer 24.

In the illustrated example, the first layer 24 forms a hair-like pattern 144 within the openings 128a and the second layer forms hat-shaped patterns 142 that cover this head.

Preferably, there is an interval 143 within each opening 128a between the pattern 142 and at least a portion of the edge of the opening 128a.

The patterns 142 and 144 are not overlapping but complement each other and occupy the entire surface bounded by the contour of the opening 128a.

According to one variant, the patterns 142 and 144 are formed by a first layer 24, the second layer 26 is a semi-transparent raster disposed within the zones of the patterns 142, There is no region of patterns 144 to constitute the background for the pattern 142. When viewed in reflected light, the patterns 142 and 144 are visible and only the patterns 142 appear on the background of the color of the second layer 26, thus enabling multicolor representation of the object in the reflected light. Further, when observed in the transmitted light, the second layer 26 is semi-transparent and the patterns 142 and 144 appear on a monochrome surface after forming an object.

In all examples, the security element and / or the security document may suggest one or more other conventional security elements that may be at the first, second or third level.

Thus, the security element may present at least one hologram or array of microlenses, and one or more emissive layers, in particular layers emitting fluorescence under UV or IR. The arrangement of microlenses can provide an enlarged image of the micropatterns of layer 24 or 26, if applicable.

The phrase "comprising" should be understood as a synonym for "including at least one" unless the context clearly indicates otherwise.

10 ... Security documents
11 ... equipment
12 ... window
20 ... Security Elements
22 ... backing
24. The first metal layer
26 ... second metal layer
28 ... opening
Patterns 30,31,35,70,142,144 ...
33 ... John
34 ... Raster
128a ... opening

Claims (23)

A security element (20) for a secure document (10)
A first layer (24) delimiting at least one half-tone raster pattern and made of a first material and perforated; And
And a second layer (26) made of a second material different from the first material and being visible through at least one opening in the first layer.
In claim 1,
Wherein the first material is metallic.
In claim 1 or 2,
Wherein the second material is metallic.
The method according to any one of claims 1 to 3,
The second layer 26 comprises a semi-transparent raster, and preferably the width d of one raster line 34 is between 20 and 25 microns and between two adjacent raster lines The spacing (t) is between 40 μm and 60 μm.
The method according to any one of claims 1 to 4,
The second layer may include one or more macro-recesses, in particular alphanumeric characters, or an opening with the same contour as the half-tone raster pattern of the first layer, And an isolated pattern with a contour corresponding to that of the raster pattern.
The method according to any one of claims 1 to 5,
The first layer 24 is formed of a first metal having an optical density DO1 and the second layer 26 is formed of a second metal having an optical density DO2 different from the first metal , And DO2-DO1 < 0.1, more preferably DO2-DO1 < 0.05.
The method according to any one of claims 1 to 6,
Wherein the first material is selected from Ag, Al, Sn and alloys thereof.
The method according to any one of claims 1 to 7,
Wherein the second material is selected from Cu, Au, Zn and alloys thereof.
The method according to any one of claims 1 to 8,
Further comprising a backing (22)
Wherein the backing comprises or consists of a foil of transparent thermoplastic material.
In claim 9,
Wherein the layers of the first material and the second material rest on opposite sides of the backing (22).
The method according to any one of claims 1 to 9,
Wherein the layers of first and second materials (24, 26) rest on the same side of the backing (22).
The method according to any one of claims 1 to 11,
Wherein the layer of second material 26 defines at least one pattern 35,142, specifically a half-tone raster pattern 142. In the embodiment of Fig.
The method according to any one of claims 1 to 12,
The layer of the first material (24) delimits a first alphanumeric pattern (30) of a positive or negative form, preferably a negative form.
The method according to any one of claims 1 to 13,
Wherein the layer of second material (26) delimits a second alphanumeric pattern (35) of a positive or negative form, preferably a negative form.
The method according to any one of claims 1 to 14,
The layer of the first material (24) extends over the entire surface of the backing (22), except for openings in the patterns.
The method according to any one of claims 1 to 15,
The layer of second material (26) extends over the entire surface of the backing (22), except for openings in the patterns.
The method according to any one of claims 1 to 16,
Wherein one of the layers (24) delimits at least one isolated pattern (31) and the other of the layers (26) has a repeating underlying pattern (35).
The method according to any one of claims 1 to 17,
The isolated pattern 31 is adapted to express the object in a half-tone raster pattern, specifically, a perspective.
In claim 17 or 18,
Wherein the basic pattern (35) is alphanumeric.
The method according to any one of claims 1 to 19,
The first layer and the second layer are patterned (144, 142) complementary to each other within the openings (128a), in particular patterns formed at least partially in half-tone, A security element that delimits patterns arranged alternately and backwards alternately.
The method according to any one of claims 1 to 20,
A security element further comprising a hidden line.
The method according to any one of claims 1 to 21,
A security element further comprising a security foil.
A security document comprising the security element (20) of any one of claims 1 to 22.

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