RU2711314C2 - Security element and security document - Google Patents

Abstract

FIELD: bindery.SUBSTANCE: invention discloses a security element for a security document comprising: a first perforated layer made of a first material and forming at least one halftone bitmap pattern; a second semi-transparent layer made of a second material different from the first, wherein said second layer is visible through at least one opening of the first layer.EFFECT: according to the invention, it is possible to obtain optical effects which are attractive to the viewer, which ensure high level of security and, in addition, difficult to reproduce.33 cl, 17 dwg

Description

The present invention relates to security documents and security features that protect such documents.

Over the years, banknotes and other secure documents, including checks, warrants, identification cards, credit or guarantee cards, formed from paper and including protective threads or protective foil, are widely used in many countries in many countries. , that is, more or less wide strips.

The security threads used in these documents are, in some cases, visible in reflected light in certain predetermined areas that are present on at least one side of the document. Such sites are called, as a rule, "windows".

The presence of security threads complicates the falsification of security documents. They help to establish the authenticity of documents due to the fact that they give them, as a rule, a different appearance in transmitted and reflected light.

From the applications EP 0059056, WO 93/08327 and WO 03/095188 various methods are known for the manufacture of papers with security thread inserted into windows.

In addition, manufacturers of security threads tend to perform them with security level 1, in which they can easily be recognized by an ordinary person, and at the same time it is difficult to fake.

Protective threads are traditionally made with areas in which patterns are reproduced in reflected light due to the presence of a metal layer with recesses that transmit light when observing a document in transmitted light

EP 1674286 A1 describes a security element for reproducing an object using an image formed from dots. It is indicated here that an image can be formed from several layers with different optical densities.

WO 99/04983 describes a security element comprising a semi-reflective layer deposited on another magnetic layer.

WO 2007/020370 A2 discloses a security thread comprising macroscopic patterns, each of which is formed from microscopic patterns.

Other security elements are disclosed in documents EP 0659587 A1, EP 0319157 A2, WO 2007/141459 A2 and WO 2013/160880 A2.

EP 0 998 396 B2 discloses a security element having two metal layers with different optical densities, for example, where one of the layers is more opaque, with a transmittance of not more than 30%, and the second layer is less opaque, with a transmittance of at least 50%. These two layers can be made of the same metal or from different ones. According to one example, the security element comprises a magnetic layer in which there may be recesses, for example, in the form of letters. A translucent layer in the form of a raster is deposited on said magnetic layer. Thus, the specified translucent layer covers the magnetic layer. According to one example, the security element contains a substrate, on the opposite sides of which are applied two identical layers, each of which is made in the form of a regular raster. In addition, on one side, between the substrate and the translucent layer, there is an unperforated layer.

EP 1503903 B1 discloses a security element comprising a substrate coated on one side with a first perforated layer of a first metal, such as aluminum, which covers a second, also perforated, layer of a second metal, such as copper. The thickness of the metal of the second layer is small enough to be translucent. In the first and second layers, the first holes are made, which are aligned with each other, and in the first layer there is also a second hole extending to the solid part of the second layer. Thus, when observing in transmitted light, you can see the contours of the first holes with a slight difference in shades in the area of separation with the holes due to the fact that light passes through one of these holes to the second layer. When observed in reflected light, a color difference can be seen for the two metals in the region of the first and second holes of the first layer. According to another example, two layers superimposed on one side of the substrate are applied, in each of which recesses are made in the form of alphanumeric characters. In some areas, the solid parts of the two layers overlap completely.

The invention proposes a further improvement of security elements, in particular security threads, which can be achieved by proposing a security element for a security document comprising:

- the first perforated layer made of the first material and forming at least one halftone raster pattern,

a second translucent layer made of a second material different from the first, said second layer being visible through at least one opening of the first layer.

Thanks to the invention, it is possible to obtain optical effects attractive to the observer, which ensure the achievement of the 1st level of security and, moreover, are difficult to reproduce.

By “translucent layer” is meant a layer having an opaque appearance when observed in reflected light and transparent when observed in transmitted light.

Preferably, the second translucent layer is also semi-reflective. By “semi-reflective layer” is meant a reflective layer which is specular when observed in reflected light at a first angle of observation or illumination, and transparent when observed in reflected light, respectively, at a second angle of observation or illumination.

The second translucent layer may have an opaque appearance when observed in reflected light, regardless of the viewing angle or lighting.

In particular, if necessary, with the help of the second layer, it is possible to form a background, the color of which will be different from the color of the material of the first layer, in reflected light without undue interference for observing a halftone raster pattern in transmitted light.

Preferably, the first material is metallic, and even more preferably metal. It is also preferred that the second material is the same. For example, the choice may be made from metals of different colors, such as copper and aluminum, or from their alloys.

It is advisable that the second layer contains a translucent raster, due to which it acquires its translucent properties. In this case, the thickness of the metal for raster lines or dots can be large enough so that the layer is locally opaque in those places where there is metal.

Thanks to the use of the raster, additional opportunities for performing drawings are opened. So, in particular, as will be shown below, raster dots or lines can be formed from elementary patterns, which allows to obtain an additional level of security.

In the second layer, one or more macroscopic grooves can be made, namely in the form of alphanumeric characters, or one hole with the same contour as a halftone raster pattern of the first layer. According to one embodiment, the second layer may have a contour corresponding to the contour of a halftone bitmap pattern, both of which are arranged so that they overlap accurately.

The layer of the first material, namely the first metal, can form at least one grayscale raster pattern and one alphanumeric pattern.

The raster of the second layer is preferably uniform and preferably contains repeating parallel lines. The sharpness of the lines and their proximity to each other can be such that when examined with the naked eye, the observer could not easily distinguish them individually at a distance of 10 cm. For example, the lines can have a width of less than 25 μm, for example, about 20 μm, and be spaced at intervals ranging from 40 to 60 m km, for example about 50 microns.

According to one embodiment, a raster of a layer of a second material, namely a second metal, is formed of dots or elementary patterns such as letters, numbers or symbols whose height is less than or equal to 100 μm and which are preferably spaced less than 40 μm relative to each other. Thus, when viewed with the naked eye and from a distance of, for example, 10 cm, you can get a view similar to (in particular, uniform) a raster consisting of parallel lines.

The raster may be interrupted in some places, which makes it possible to form at least one pattern, namely a microscopic pattern, preferably an alphanumeric pattern, in the layer of the second material, namely from the second metal.

A layer of the first material, namely, of the first metal, can form the first alphanumeric pattern in positive or negative.

The layer of the second material, namely the second metal, can form a second alphanumeric pattern in positive or negative. The second picture can carry the same information as the first, for example, with the display of the same number or the same letter or with the transfer of the same meaning.

At least one of the layers of the first and second materials, namely the first and second metals, may contain one or more patterns in the form of a combination of dots or symbols.

The pattern (s) present (present) in the layer of the first material, namely, the first metal, can (can) be positioned with fixation of their position relative to the pattern (s) present (present) in the layer of the second material, namely the second metal, i.e. so that the relative positions of the patterns of the two layers can remain constant along the entire length of the element during its manufacture.

The pattern (s) formed (formed) in the layer of the first material, namely, the first metal, can (can) be visually independent (independent) of the pattern (s) formed (formed) in the layer of the second material, namely the second metal, that is, the drawings of each of the layers should not complement each other so that their full meaning is revealed to the eyes of the observer in transmitted and / or reflected light.

According to one embodiment, 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. So, for example, these figures reproduce an object, number or word. For example, one of the drawings forms the face of a person, and the second - the hairstyle of a person. Thanks to this, it is possible to achieve a multi-color display of the object in reflected light, which is especially attractive.

According to one embodiment, 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. So, for example, these figures restore an object, number or word. For example, one of the drawings forms the face and hairstyle of a person, and the second - the background on which the hairstyle is depicted. Thanks to this, it is possible to achieve a multi-color display of the object in reflected light, which is especially attractive.

Each of the complementary drawings may contain solid lines in positive or negative. In addition, one of them can contain only solid lines in positive or negative, and the second - a grayscale image. According to another embodiment, each of the complementary patterns reproduces a grayscale image, and in some cases, each of them contains one or more solid lines in positive or negative.

The patterns formed by the layers of the first and second metals can be geometrically connected or relate to the same object, for example, an object or a living creature, and in particular be identical, which can facilitate their comparison. For example, they display the same symbol or the same image, but have different sizes, or one is made in positive and the other in negative.

The layer of the first material, namely the first metal, can be stretched over the entire surface of the substrate, with the exception of the holes in the patterns. The layer of the second material, namely the second metal, can be stretched over the entire surface of the substrate, with the exception of the holes of the drawings. In particular, the width of the layers of the first and / or second materials may be equal to the width of the substrate. In one embodiment, it is less than the specified width.

One of the layers can form a separate pattern, namely macroscopic, and the second layer may contain a repeating elementary pattern, namely microscopic.

A separate picture can be a halftone raster, in particular, display an object that is visible in perspective, with shadow effects obtained due to the raster. As a result of this, a volumetric effect is obtained on the basis of a binary raster.

The elementary pattern can be alphanumeric or display a character.

According to one exemplary embodiment, the first layer and the second layer form patterns that complement each other in the holes, namely patterns, each of which is formed at least partially in semitones, and more preferably patterns that are alternately face up and face down along the security feature.

According to one exemplary embodiment, the first layer forms patterns that, for example, complement each other while displaying any object.

Each of these patterns is formed, for example, by a halftone raster. The second layer is a translucent raster that covers only one of the two drawings of the first layer. Thus, in reflected light, the two patterns of the first layer have a different appearance, since one of them is superimposed on the raster of the second layer, which gives the specified pattern a color different from the color of the second pattern, and the display of the object is multicolored.

On the other hand, in transmitted light, the patterns are monochrome.

The security element may comprise a security thread or foil.

According to another aspect, regardless of what is said above, or in combination with this, the invention relates to a security element for a security document containing:

- substrate

- the first perforated layer made of the first material, on one side of the substrate

- a second layer made of a second material different from the first and containing a translucent raster visible through at least one hole of the first layer, the second layer being between the indicated side of the substrate and the first layer.

According to another aspect, regardless of what is said above, or in combination with this, the invention also relates to a security element, comprising:

- a substrate having at least one transparent portion,

- in this section, a layer of the first metal with an optical density of DO1 and a second layer of a second metal other than the first with an optical density of DO2, with DO2-DO1 <0.1, more preferably DO2-DO1 <0.05.

The optical density of DO is determined by the expression DO = -logT, where T is the transmittance measured in accordance with the requirements of ISO 15368.

Thanks to the security element according to the last aspect of the invention, it is possible to achieve level 1 security when it is easily recognized by an ordinary person and at the same time is difficult to counterfeit. So, in particular, metal layers can provide 3rd level security, thereby allowing you to check whether the optical density has the expected and fairly close values.

In the systems described above, the substrate is preferably a film of a transparent thermoplastic material.

The layers of the first and second materials, namely metals, can be located on two opposite sides of the substrate or on the same side of the substrate and at least partially overlap each other, preferably not completely.

The layer of the first material, namely the first metal, can carry the first information visible on the front side in reflected light, in the form of a pattern recognized by the naked eye or when enlarged, preferably in the form of a grayscale image and an alphanumeric pattern.

The layer of the first material is preferably opaque and, in particular, has an optical density in the absence of holes, that is, if we consider the continuous surface of the specified layer, more than 0.8.

The layer of the second material, namely the second metal, can carry the second information visible on the back in reflected light, for example, in the form of a pattern recognized by the naked eye or when enlarged, preferably in the form of microscopic, namely alphanumeric, patterns.

These two sections of information remain preferably visible also in transmitted light in the presence of relative transparency of the constituent elements of the system.

The presence of information on one of the two layers, visible only when enlarging, for example, a small raster on the layer of the second material, namely the second metal, and / or microscopic drawings such as alphanumeric, provides 2nd level security, enhancing 1st level security.

The invention also relates to a security document containing a security element according to any of the above aspects of the invention.

Patterns of metal layers can be formed by metallization and / or demetallization of the substrate, that is, using any technology involving at least one step of metallization and / or demetallization of the substrate. In particular, selective metallization technology or metallization technology followed by selective demetallization can be used. It is preferable to use metallization technology with subsequent selective demetallization of the substrate. According to one embodiment, at least one of the layers of the first and second metals is applied by printing.

By "selective metallization" or "selective demetallization" is meant, respectively, incomplete metallization or demetallization, that is, one that is not carried out over the entire surface of the substrate, which allows the formation of at least one pattern. Metallization can be carried out in vacuum or electrochemically.

By “metal layer” is meant a layer of one or more metals used as such or in the form of alloys. The metal of each layer is selected, for example, from metals commonly found in protective threads, namely, from among such as Al, Cr, Ni, Ag, Au, Cu, Sn.

The first metal or, conversely, the second metal is preferably selected from the group consisting of Ag, Al, Sn and their alloys. The second metal or, conversely, the first metal is preferably selected from the group consisting of Cu, Au, Zn and their alloys.

The first metal can be achromatic, that is, characterized by a substantially uniform absorption in the entire visible region of the spectrum, and the second layer can have a color, for example, golden or copper, or vice versa. According to one embodiment, the first metal is holographic or serves as a reflective layer in the interference structure, namely, a multilayer interference structure, or in a structure where there is a color change with a change in the viewing angle (in English “colorshift” - “color shift”) .

All metals used may be non-magnetic. In one embodiment, at least one of them is magnetic.

When the security element according to the invention forms a security thread, its width is, for example, in the range from 0.5 to 15 mm, more preferably from 3 to 8 mm.

The metal thickness of the layer of the first or second metal should preferably be small enough so that the layer is translucent, with an optical density of preferably less than or equal to 0.8.

Below, for the following metals, examples of corresponding values providing a specified density of less than or equal to 0.8 are given.

The values of the optical density of the layers of the first and second metals can be such that in the absence of holes, that is, if we consider the continuous surface of each of these layers, the security element would not be opaque in transmitted light, while the optical density associated with the application of layers on the plot overlapping solid surfaces would preferably be less than or equal to 0.8.

According to one preferred embodiment, the first metal is opaque and the second metal translucent.

The first and / or second metals may be in direct contact with the substrate or, according to one embodiment, cover at least one intermediate layer in contact with the substrate, for example, a layer used to enable selective metallization and / or demetallization of the substrate.

By “pattern” is meant any pattern recognized by the naked eye, in particular, such as one or more alphanumeric characters, or an image of an object such as an image of a famous person, animal, object, landscape, plant or monument. By “halftone bitmap pattern” is meant a pattern that is preferably visible in 3D due to the shading effect, which is achieved using grayscale reproduction of shadows. Applicant has proposed protective threads with halftone raster patterns under the name Picture Thread ™.

A pattern can be formed with multiple holes of the same or different size.

The pattern on the layer of the first material, namely the first metal, or the layer of the second material, namely the second metal, can be found in other places of the protected document, for example, in the form of a watermark or print. For example, the value of the bill is visible simultaneously on the layer of the first and / or second metal, and on the backing of the document as a print.

The invention also relates, regardless of what is said above, or in combination with this, to a security document containing:

- substrate

- a layer of the first metal,

- a layer of a second metal other than the first one, which is at least partially superimposed on the layer of the first metal, wherein at least one hole is made in the layer of the first metal, forming at least one first alphanumeric pattern, the layer of the second metal contains a raster, preferably translucent.

Preferably, the second metal layer is formed with two holes forming second repeating patterns, the size of said second patterns being smaller than the size of the first pattern, with the second patterns at least partially overlapping the first pattern.

The second patterns are preferably microscopic patterns that can be formed by interruptions of the raster.

The first pattern and the second patterns can display the same word or number.

The first layer may also form a grayscale pattern.

The invention will become more clear in the course of familiarization with the description of examples of non-limiting embodiments, and consideration of the attached drawings, in which:

- FIG. 1 illustrates a front view of an example of a security document according to the invention;

- FIG. 2 illustrates, in partial and schematic longitudinal section, a security element according to the invention;

- FIG. 3 and 4 illustrate views of the front and back sides of the security element of FIG. 2;

- FIG. 5 and 6 illustrate callouts, respectively, of figures 3 and 4;

- FIG. 7 and 8 are views similar to those of FIG. 3 and 4 and illustrating one embodiment of a security element;

- FIG. 9 and 10 illustrate callouts, respectively, of figures 7 and 8;

- FIG. 11-13 are views similar to those of FIG. 2 and illustrating various embodiments;

- FIG. 14 illustrates an example of halftone bitmap patterns made on a first layer of a security element according to one embodiment;

- FIG. 15 illustrates an example of a translucent raster formed by a second layer and forming a separate pattern configured to overlap one of the halftone patterns shown in FIG. 14;

- FIG. 16 illustrates a security element formed by overlaying the drawings of FIG. 14 and 15, in reflected light;

- FIG. 17 illustrates one embodiment of a security element.

In these drawings, various constituent elements are not always shown for clarity in contact with each other or in compliance with the corresponding real proportions.

Possible additional layers, such as adhesive layers or protective layers, are not shown here.

In FIG. 1 illustrates a security document 10 comprising a security element 20 according to the invention.

As security document 10, in particular, a banknote can be used. The security document preferably comprises a fibrous substrate 11, wherein the security element 20 in this example looks like a security thread elongated from one edge of the substrate 11 to its other edge.

According to one embodiment, the security document substrate 11 is a polymer substrate or a hybrid polymer-paper substrate, wherein the security element may be located, for example, on the surface of the polymer substrate in the form of a strip applied by a transfer method (the so-called “foil”).

In the illustrated example, the security thread 20 is inserted into windows that have according to FIG. 1 front side, visible in reflected light through a window 12 in the substrate 11.

The length L of the window 12, measured in a direction parallel to the longitudinal axis of the element 20, is preferably greater than or equal to 5 mm, and even more preferably 10 mm.

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

According to FIG. 2, the security element 20 has a substrate 22, preferably made of a transparent plastic material, for example, polyester.

The thickness e of the substrate can be from 6 to 60 microns.

In the example illustrated in FIG. 2, a layer 24 of a first metal is applied to one side 23 of the substrate 22, and a second metal layer 26 other than the first is applied to the opposite side 25.

Layer 24 of the first metal can have an optical density of DO1, and layer 26 of the second metal can have an optical density of DO2, while these two optical densities are preferably close, so that | DO2-DO1 | <0.1.

The optical density DO of the metal layer is determined by the expression DO = -logT, where T is the transmittance measured in accordance with the requirements of ISO 15368.

When measuring, the raster is taken into account. The first layer may be opaque, and the second raster layer may be translucent so that the pattern of the first layer remains visible when observed in transmitted light.

Preferably, the first metal is achromatic, holographic, or serves as a reflective layer in an interference structure, namely a multilayer interference structure, or in a structure where a “color shift” effect occurs, while the second metal should have a color, or vice versa.

Aluminum can be used as the first metal, and copper or a copper alloy with a copper or golden color as the second metal, or vice versa. Preferably, both the first metal layer and the second metal layer were perforated to form patterns visible in reflected and / or transmitted light to the naked eye and / or when magnified. At least one of the layers 24 and 26 may also be perforated to form a raster.

Holes 28 formed in the first metal layer 24 are shown in FIG. 2 very schematically, like the holes 29 formed in the layer 26 of the second metal, the shape and relative positions of these holes may vary depending on the appearance that you want to give the protection element.

Next, with reference to FIG. 3-6, a first exemplary embodiment of a security element is described.

According to this embodiment, the first metal layer 24 is visible on the front side of the security element, and the second metal layer 26 is visible on its reverse side. The security document 10 can be made so that it is possible to observe in reflected light only the front side of the security element, or according to another embodiment at the same time its front and back sides, for example, due to the presence of windows on the front and back sides of the document substrate or a special through window .

According to FIG. 3, the layer 24 can be made with holes in the form of alphanumeric patterns 30, for example, with the number 100, and these patterns 30 are executed on the front side and in the forward and reverse directions.

The alphanumeric (digital) pattern (s) 30 may (may) have, for example, a size sufficient so that it (they) can be seen with the naked eye, with a height of, for example, at least 1.2 mm.

It is also possible to execute patterns 31 in the layer 24, preferably visible to the naked eye, in the form of bitmap images providing reproduction with a shading effect.

According to the illustration, this may be an image of a person.

According to FIG. 3, a halftone raster pattern 31 contains dots 32, the size of which varies depending on the position in the image, which allows you to create a shading effect.

In this example, the points 32 are, for example, polygonal in shape, and the raster is made with amplitude modulation, that is, the step with which the points are located is uniform, but the size of the points changes. In one embodiment, the raster may be frequency modulated. The shape of the dots can be very diverse.

According to the illustrated example, figure 31 may also include areas 33 indicated by solid lines — these may be, for example, nose or eyes.

You can refer to publication EP 1674286 A1, which discloses the receipt of raster images with a relief effect.

It is advisable that the protection element 20 was made according to the illustrations with alternating alphanumeric patterns 30 and halftone patterns 31 in the longitudinal direction.

Turning now to the consideration of FIG. 4 and 6, it can be seen that the second metal layer 26 in the above example contains small rasters 34 that are spaced at regular intervals and interrupted to form patterns 35. These patterns 35 are preferably repeated and in this case represent the number 100.

The size of the pattern 35 is preferably smaller than the size of the pattern 30. The raster formed by the lines 34 may look uniform when observed with the naked eye if the lines 34 are sufficiently thin and are close to each other.

According to FIG. 6, preferably the width d of the raster lines 34 is from 20 to 25 μm, and, for example, the distance t between two adjacent rasters 34 is from 40 to 60 μm.

For example, lines 34 with a width of 20 μm and a distance t between them of 50 μm can be provided. Said lines 34 may be oriented obliquely with respect to the longitudinal axis of the substrate 22 or in another way according to another embodiment. Lines 34 may be straight as shown in the figures. According to one embodiment, said lines 34 are curved, namely wavy.

Preferably, the number of lines 34 per inch is greater than or equal to 800, preferably 2000, which will prevent any attempt to reproduce these lines using a conventional printer having a lower resolution.

Figures 35 are preferably microscopic and can be observed with magnification.

The height of the figures in Figure 35 is, for example, 100 μm.

According to FIG. 4, the figures 35 are executed on the reverse side in the opposite direction so that on the front side they look made in the forward direction.

More specifically, a comparative study of figures 3 and 4 shows that patterns 35 can appear in the holes of patterns 30 and 31 formed in layer 24 in reflected light.

Likewise, layer 24 can be seen in reflected light through patterns 35, where patterns 35 are superimposed on the metallized solid surface of layer 24 if the security element 20 can be observed in reflected light from the back.

Where figures 35 are superimposed on the holes of figures 30 and 31, observation is possible through the substrate 32 of the security element, namely in transmitted light.

According to the examples in FIG. 3-6, the opacity of the layer 24 is such that when observing the protection element 20 in reflected light from the front side, the patterns formed in the layer 26 can only be seen in the area of the openings of the patterns 30 and 31 of the layer 24.

When the security element 20 is viewed from the back, if possible due to the nature of the security document, as in FIG. 4, due to the discontinuity associated with the presence of raster lines 34, the second metal layer 26 can be perceived by the observer as having a substantially uniform color in reflected light where it is superimposed on the solid surfaces of layer 24. Due to this, the security element in places other than the area of figures 35, it acquires a special color on the reverse side, associated with the imposition of raster lines 34 and layer 24 and with the visibility of layer 24 between lines 34.

By choosing the ratio between the area occupied by the raster lines and the unallocated area, you can change the explicit shade of the layer 26 on the raster section between the pure color of the second metal and that of the first metal.

The color of the layer 26 in the region of the openings of figures 30 and 31 appears differently due to the absence in the region of the location of the indicated openings of the first metal layer 24.

Thus, it is possible to obtain several color nuances in reflected light, which are difficult to reproduce, given that the raster lines 34 can be made with very high definition and with high attractiveness for the observer.

Thanks to such color nuances obtained with the help of metal coatings, additional security is achieved.

Preferably, the surface structure of the layers 24 and 26 is such that a mirror-like metallic reflection can be generated on their surface.

It is possible to obtain additional optical effects by selecting the specified surface structure, for example, by creating a microrelief in some areas.

According to the examples in FIG. 7-10, the first metal layer 24 reproduces the same figures 30 and 31 as in the example of FIG. 3. The layer 26 of the second metal, which is visible from the back, contains parallel raster lines 34, as in the previously described example. On the other hand, said raster lines 34 form patterns 40 having the same size as those of patterns 30.

Again, two tones are obtained in the metallic color region of the layer 26, namely, a tone corresponding to the superposition of the raster lines 34 on the layer 24, and a tone corresponding to the superposition of the raster lines 34 on the holes of figures 30 or 31.

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

In particular, as shown in FIG. 11 instead of placing the layers 24 and 26 on both sides of the substrate 22, you can place them on the same side.

In FIG. 12 illustrates the possibility of incomplete overlapping of the layers 24 and 26 of the first and second metals.

According to the example of FIG. 12 layers 24 and 26 are superimposed only in the area 50, for example the central, of the security element.

According to the embodiment of FIG. 13, the layers 24 and 26 are not located on the same side of the substrate 22, as in FIG. 12, but on its opposite sides.

According to the example of FIG. 14-16, the first layer 24 comprises a grayscale raster pattern that is superimposed on a separate pattern 70 of the second layer having the same outline.

The metal of the raster of the second layer 26 is visible in the holes of the halftone raster pattern, the visibility of the details of which it changes in reflected light. Thus, this pattern becomes visible in reflected light with a reflective background color of the second metal.

Due to the second halftone bitmap of FIG. 16 does not overlap with the pattern 70 of the second layer, it is possible to obtain a halftone raster pattern when observing in reflected light, giving an image with a relief effect on a transparent background, and a second image of the same object with a relief effect on a different background, namely a reflective one. Both patterns are visible when viewed in transmitted light.

In FIG. 17, a security element 20 is shown, in the first layer 24 of which the first holes 128a are made to provide visibility in reflected light to a pattern of the first type, in this case a face, and second alphanumeric holes 128b, in this case a number corresponding to the face value of the banknote.

The hole patterns 128b are preferably arranged, as shown here, alternately face up and face down when moving along the security element. The same can be said about the patterns of holes 128a. Due to this, it is possible to simultaneously obtain patterns that can be observed in the forward direction in reflected light both on the front and on the reverse sides of the element 20.

Layer 24 is made, for example, of a first metal such as aluminum. The pattern formed in the openings 128a may be a halftone bitmap pattern, which allows reproducing the shading effect.

The element 20 also contains a layer 26 of a second metal other than the first, for example, copper or copper alloy. The specified second layer 26 is translucent, which is explained, for example, by the thickness of the metal.

The second layer 26 is visible in reflected light, on the one hand, in the holes 128b, where it forms patterns 140 that reproduce the meaning of those formed by the holes 128b, in this case the same numbers.

Between the layers 24 and 26 within the holes 128b there may be a gap 141.

In 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 in the holes 128a a pattern 144 in the form of a head, while the second layer forms patterns 142 in the form of a headdress covering the specified head.

It is preferable to provide a gap 143 in each hole 128a, between the pattern 142 and at least a portion of the edge of said hole 128a.

Figures 142 and 144 are not superimposed, but complement each other and together occupy the entire surface area limited by the contour of the hole 128a.

According to one embodiment, the patterns 142 and 144 are formed by the first layer 24, and the second layer 26 is a translucent raster located in the pattern area 142 and not in the pattern area 144, so that it forms a background for the patterns 142. When viewed in reflected light, the patterns 142 and 144 are visible, while only the patterns 142 appear on the background of the color of the second layer 26, which allows you to get a multi-color display of the object in reflected light. In addition, when observed in transmitted light, the second layer 26 is translucent, and figures 142 and 144 form an object that is visible as a single-color image.

In all of these examples, the security element and / or security document may have one or more other generally accepted security elements, which may be characterized by a first, second or third level.

The security element may contain at least one hologram or microlens matrix, namely one or more layers, luminescent, namely fluorescent, in UV or IR. The lens matrix is capable of providing, if necessary, an enlarged image of the micrographs of the layer 24 or 26.

Unless otherwise specified, the expression "containing any ..." should be interpreted as a synonym for the expression "containing at least one ...".

Claims (35)

1. The security element (20) for the security document (10), comprising: - the first perforated layer (24) made of the first material and forming at least one grayscale raster pattern, - a second translucent layer (26) made of a second material different from the first, said second layer being visible through at least one opening of the first layer. 2. The element of claim 1, wherein the first material is metallic. 3. The element of claim 1, wherein the second material is metallic. 4. The element according to claim 1, in which the second layer (26) contains a translucent raster. 5. An element according to claim 4, in which the width (d) of the raster line (34) lies in the range from 20 to 25 μm and the interval (t) between two adjacent raster lines (34) lies in the range from 40 to 60 μm. 6. The element according to claim 1, in which the second layer contains one or more macroscopic recesses. 7. The element according to claim 6, in which one or more macroscopic recesses are made in the form of alphanumeric characters or there is a hole with the same contour as the halftone raster pattern of the first layer, or a separate pattern with a contour corresponding to the contour of the halftone raster pattern of the first layer. 8. An element according to claim 1, in which the first layer (24) is made of the first metal with an optical density of DO1, and the second layer (26) is made of a second metal other than the first with an optical density of DO2, while DO2-DO1 < 0.1. 9. The element of claim 8, wherein DO2-DO1 <0.05. 10. The element according to claim 1, in which the first material is selected from the group including: Ag, Al, Sn and their alloys. 11. The element according to claim 1, in which the second material is selected from the group including: Cu, Au, Zn and their alloys. 12. The element according to claim 1, containing the substrate (22). 13. The element of claim 12, wherein the substrate comprises a film of a transparent thermoplastic material or is formed by a film of a transparent thermoplastic material. 14. An element according to claim 13, in which layers of the first and second materials are located on opposite sides of the substrate (22). 15. An element according to claim 12, in which layers (24, 26) of the first and second materials are located on the same side of the substrate (22). 16. The element according to claim 1, in which the layer (26) of the second material forms at least one pattern (35; 142). 17. The element of claim 16, wherein said pattern is a halftone raster pattern (142). 18. An element according to claim 1, in which the layer (24) of the first material forms the first alphanumeric pattern (30) in a positive or negative form. 19. The item according to claim 18, wherein said figure (30) is presented in negative form. 20. The element according to claim 1, in which the layer (26) of the second material forms a second alphanumeric pattern (35) in a positive or negative form. 21. The element of claim 19, wherein said pattern is presented in negative form. 22. An element according to claim 1, in which a layer (24) of the first material is elongated over the entire surface of the substrate (22) with the exception of the pattern holes. 23. An element according to claim 1, wherein the layer (26) of the second material is elongated over the entire surface of the substrate (22) with the exception of the pattern holes. 24. The element according to claim 1, in which one (24) of the layers forms at least one separate pattern (31), and the second layer (26) contains a repeating elementary pattern (35). 25. The element of claim 24, wherein the individual pattern (31) is a halftone raster pattern. 26. The item according to p. 25, in which the specified image displays an object that is visible in perspective. 27. The element according to claim 25, in which the elementary pattern (35) is alphanumeric. 28. The element of claim 25, wherein the first layer and the second layer form patterns (144, 142) that complement each other in the holes (128a). 29. The element of claim 28, wherein each of said patterns is formed at least partially in semitones. 30. The element of claim 29, wherein said patterns are alternately face up and face down along the security element. 31. An element according to claim 1, comprising a security thread. 32. The item according to claim 1, containing a foil. 33. A security document containing a security element (20) according to claim 1.

Images