EP2819851B1 - Security label and a method for the production thereof - Google Patents

Description

The invention relates to a tamper-proof carrier according to the preamble of claim 1, and to a method for producing a tamper-proof carrier.

As counterfeit protection for products, documents and passes optically variable elements are used. Optically variable elements contain structures of very high resolution which produce special optical effects. Such structures are difficult to copy and usually can not be displayed with normal printing technology. Optically variable elements may include structures that are visible and verifiable to the naked eye as well as structures that are verifiable with either simple or special readers. Optically variable elements are widely known and are widely used. The optically variable elements include, for example, holograms, kinegrams and lithographs. The structures contained in optically variable elements may be holograms, specifically rainbow holograms, transmission holograms, reflection holograms, 2D holograms, 3D holograms, Fourier holograms, Fresnel holograms, volume holograms, and kinoforms. Such holograms can either be generated optically directly or calculated in the computer. Furthermore, diffractive structures may be included, in particular diffraction gratings. Refractive structures such as Fresnel lenses or blazed gratings may be included. It may contain scattering elements, such as diffusers. Numerous other structures are described in the literature which may be contained in optically variable elements. The various structures may be partially superimposed to accommodate two or more effects in the same region of the optically variable element. The various structures can be used to design graphical elements such as guilloches, logos, images, lines, surfaces, etc. Furthermore, textual elements can be designed, such as lettering, numeric or alphanumeric serial numbers, micro-typefaces. Furthermore, functional elements can be designed, such as barcodes or other machine-readable structures. The various structures and elements are skillfully combined into an overall design for the variable optical element which, if possible, meets all the requirements for safety, functionality and aesthetics of the variable optical element.

Optically variable elements can be produced in a replication process. For this purpose, a master stamp with a special overall design is created in a complex manner. Such master embossing dies can be produced in an electron beam lithography method or in a dot matrix method, wherein high resolutions can be achieved. In the case of electron beam lithography, resolutions of down to a few nanometers can be achieved. In the case of the dot matrix method or other interference methods, diffraction gratings with a lattice constant of down to a few 100 nanometers can be produced. From the master stamp can in turn daughter stamping be generated and of these more daughter stamping. The embossing dies are then used in an embossing process to emboss a larger amount of optically variable elements. In such an embossing process, the generated optically variable elements are substantially all the same.

Considered as the closest prior art EP 0420 261 B1 discloses a method in which individualization measures are introduced by changes at different points of the embossing process in order to make optically variable elements produced in an embossing process even safer and to introduce additional data into the optically variable elements. This allows batch information or serial number information to be added to the optically variable element. However, the customization measures described are limited and relate to destruction, overprinting or non-use of certain areas in the original design, since the original design can not be redesigned by the measures mentioned. In particular, no holographic, diffractive or otherwise optically variable individual structures can be produced by the individualization measures described.

WO 2010/028758 A1 describes a method for producing a security element, in which a layer composite with a mask layer, which may be an embossed metal layer, and a laser-modifiable marking substance are exposed to laser radiation in order to simultaneously and accurately generate negative markings in the mask layer and color-changed markings in the marker.

Out DE 10 2006 032 234 A1 For example, a bill is known which comprises a carrier layer with a recess and a transparent window foil which covers the recess and is connected to the carrier layer; by an individualizing feature - which may be a lithographic microstructure - a security feature is created, which is connected in the region of the recess with the window film.

The invention has for its object to make carriers even more tamper-proof and to provide a method for their preparation.

The object is fulfilled with regard to the product by a tamper-proof carrier with the features of claim 1. Preferred developments are the subject of the dependent product claims.

The counterfeit-proof carrier according to the invention can take many forms. In particular, they can be designed as a self-adhesive label or as a heat-sealable material. The label shape or shape of the heat seal stamp may be arbitrary, e.g. circular, oval, polygonal, polygonal with rounded corners, etc. In the case of the heat seal material, the overall design may also be designed as a long strip which is sealed to the substrate in its entire length. Such strips are known from tickets, tickets or banknotes ago. Surprisingly, it has been found that the security against forgery of carriers of optically variable elements can be increased if the optically variable elements have a non-individual embossed structure and the at least one optically variable element additionally has an individual laser lithographic structure with a resolution of less than 20 μm. The inventive counterfeit-proof carrier has at least one metallized layer, wherein preferably the non-individual embossed structure as well as the individual laser lithographic structure are incorporated in the same metallized layer. The combined joining of non-individual embossing structure and individual laser lithographic structure in the same optically variable element significantly complicates its replication.

For this purpose, the lithographic structure has a resolution of less than 20 μm, preferably less than 5 μm. In this case, resolution below 20 microns or 5 microns means that the structural incarnations have expansions of less than 20 microns or 5 microns and distances from each other of less than 20 microns or 5 microns. These expansions and distances are preferably maintained at each of the embodiments, but at least of a plurality of the embodiments. In the case of pixels introduced by a laser into the metallized layer, this resolution means that the individual pixel should have a diameter of less than 20 μm or 5 μm and that the distance between the pixels should be less than 20 μm or 5 μm.

The term of the carrier is to be understood very generally here, it can be deformable strips, in particular a strip-like multilayer film, an adhesive tape, but also a stiff strip.

Along the carrier are a variable optical element or a plurality of variable optical elements, preferably arranged along the carrier. Preferably, the carrier is separable between the optically variable elements so that each individual optically variable element can be used as a stickable or heat sealable label, Holospot or the like. is reusable.

Metallic films or metallized paints are used as the substrate material for the support. This can be first embossed and then metallized or vice versa. The relief of the embossing can be embossed into the metal layer. The metal layer is not destroyed by the embossing and serves as a reflection layer to reflect back the light diffracted by the embossed structure back into the room.

In some applications, e.g. In order to increase safety, it may be desirable for the metal layer to be partially demetallised. In the case of the embossed optically variable elements, this is usually accomplished in a second, independent of the embossing process.

DE 34 30 111 C1 describes such a process. It may be partially applied prior to metallization, a release layer, which is washed out after the metallization together with the metal layer. In areas where no release layer has been applied, the metal is retained. Here, there is the difficulty of aligning the embossing precisely to the partially demetallized metal layer. Furthermore, an individualization of such demetallizations is not described. Because printing processes are used to apply the release layer in such processes, the resolution in these processes is limited. Typically, a minimum of 20 microns is achieved.

A way of individual demetallization describes DE 41 31 964 A1 , Here, a laser marking method is used to demetallize the metal layer of a hologram individually. However, in this process can be through the Laser beam does not produce holographic, diffractive or otherwise optically variable individual structures. Furthermore, the resolution in the demetallization of such a laser marking process is limited. Typically, a minimum of 20 microns is achieved.

No restrictions on the individualization are given in the direct production of optically variable elements. Here, the optically variable elements are not generated via a replication process, but introduced directly into the target substrate or in an intermediate product. This can e.g. by individually exposing a photosensitive film followed by development. Another example is high-resolution laser lithography, in which the desired structures are introduced directly into a laser-sensitive layer by means of a laser beam. There are processes that require subsequent development and those in which the optically variable element no longer needs to be developed. Here, the high-resolution laser lithography is to be distinguished from the classic laser marking, since only in the high-resolution laser lithography so small feature sizes are achieved that a use of the exposed structure as an optically variable element is possible. In the following, reference is exclusively made to high-resolution laser lithography, in which the base resolution and the feature sizes are smaller than 20 μm, preferably smaller than 5 μm.

In laser lithography, a structure to be exposed is transferred into a substrate by means of a laser beam. The structure to be exposed is specified or calculated by means of a computer and is available in the form of image or vector data. The image or vector data is used by the laser lithograph to control the position of the laser beam relative to the substrate and to control the intensity and duration of the laser beam impinging on the substrate. In laser lithography, several methods have been established. Thus, a writing beam can stand firmly in the room and the substrate can be moved relative to it. It can also be the substrate fixed in space and the writing beam are moved relative to this. Furthermore, both substrate and laser beam can be moved. It is also possible to modulate the writing beam by means of a surface light modulator and thus to expose a larger area of the substrate at once. Even with this principle, writing beam and substrate can be moved.

In laser lithography, the resolution is limited by the wavelength used and the optics used. In order to be able to generate as high-resolution structures as possible, therefore, preferably small wavelengths are used. Suitable wavelengths are in the range of 0.2 .mu.m to 10 .mu.m, preferably in the range of 0.2 .mu.m to 1 .mu.m. Smaller wavelengths are also possible. At these wavelengths structures can be generated that are effective in the range of visible light (wavelength about 0.4 microns to 0.7 microns). Thus, diffraction gratings with lattice constants on the order of the visible light can be generated, which have large diffraction angles and therefore can be perceived particularly well. Holograms also have correspondingly large diffraction angles. Optically variable elements can be produced only with high-resolution laser lithography, wherein the base resolution must be less than 20 microns, preferably less than 5 microns.

Due to the manufacturing process, optical elements produced by laser lithography can be fully customized in design. All structures can be designed individually. This can be done using numeric or alphanumeric serial numbers, or by individual graphic elements such as images or guilloches.

Metallic films or metallized coatings are used as the substrate material for the laser lithography, as in the embossed optically variable elements. In this case, the wavelength, intensity, pulse duration, shape and writing energy of the laser beam can be adjusted so that the substrate material is demetallised at certain predefined locations and thus becomes transparent or semitransparent. This is done either by ablation of the metal layer, by shifting the metal layer towards the edges of the exposed area or by converting the metal layer into a transparent or semi-transparent oxide layer. There may also be a mixture of the three mentioned effects. The demetallization can be aligned precisely with the other structures that can be generated by laser lithography, since it can be introduced in the same exposure process. Since the demetallization in laser lithography is principally carried out with the high resolution of the laser lithographic process, high-resolution demetallized structures can be produced with it. These include micro-typefaces, scattering structures, gray values or gray value wedges. Such gray levels can be generated by suitable halftoning in a halftone process, wherein in a surface only a certain proportion of Surface rastered demetallisiert. In the case of gray value wedges, the demetallised surface area gradually increases due to the adaptation of the screening in the area.

In addition to complete demetallization, laser lithography also makes it possible to reduce the thickness of the metal layer by precisely adjusting the introduced laser energy during the writing process. By reducing the thickness of the metal layer, the light transmission of the metal layer increases. This also allows gray values and gray wedges to be generated.

The production of optically variable elements with high-resolution laser lithography is subject to certain limitations. Thus, the basic resolution is limited by the wavelength of the write laser used and by the optics used. Since high write speeds and thus high throughput are to be achieved in a mass production, it is desirable to further reduce the resolution, since then larger areas can be exposed in a shorter time. Typical base resolutions used here are 0.5 μm to 5 μm. So it is to be assumed in the laser lithography of a limited resolution. In the production of diffractive structures, e.g. Grids or holograms can not be reached by the limited resolution of all diffraction angles. Furthermore, the phase or amplitude modulation to be achieved with laser lithography is not ideal in the material, so that the theoretically maximum possible diffraction efficiency of the diffractive structures is not achieved.

According to the invention, it has been recognized that the limitations imposed on the embossed optically variable elements and the limitations imposed on the laser-lithographically generated optically variable elements are in part complementary. Thus, embossed optically variable elements can not be fully customized in a simple manner, while this is the case with laser-lithographically produced optically variable elements. Embossed optically variable elements can only be demetallized in a second process step, while laser-lithographically generated optically variable elements can be accurately exposed and demetallized in one process. The demetallization of the embossed optically variable elements is done with low resolution, while the demetallization in the laser lithographic process can be done with full resolution of the process. Laser-lithographically generated optically variable elements are usually limited in limiting a limited resolution, while such a limitation in the embossed optically variable elements does not exist. Furthermore, they are usually subject to the limitation of a limited diffraction efficiency, while with optically variable elements very high diffraction efficiencies can be achieved.

According to the invention, it has been recognized that substrate material exists which is suitable both for embossed optically variable elements and is suitable for optically variable elements produced by laser lithography. Such materials are metallized films or paints in a composite layer. In order to enable an efficient laser lithographic exposure, the optical density (OD) should be as low as possible. On the other hand, the smaller the OD, the lower the degree of the degree of metallization of the metallized layer. As a suitable range for the OD, the range of 0.1 to 10 has been found, preferably 0.8 to 3.

With regard to the method, the object is achieved by a method having the features of claim 9. Preferred developments are the subject of the dependent subclaims.

According to the invention, a non-individual embossed structure is embossed into the metal layer of a carrier and, in addition, a laser-lithographic structure is exposed in the metallized layer by means of a laser. In this case, the lithographic structure is exposed with a resolution of less than 20 μm, preferably less than 5 μm, and the embossed structure and the lithographic structure jointly form at least one optically variable element. However, higher resolutions of 1 μm or less are also conceivable.

In a preferred embodiment of the invention, the optically variable elements are embossed in a first process step and exposed in a second process step laser lithography. In a further embodiment of the invention, the optically variable elements are exposed in a first process step laser lithography and embossed in a second process step. In a further embodiment of the invention, the optically variable elements are first embossed, then applied to an article, preferably glued or sealed and subsequently exposed in a further process step by laser lithography. In this case, the article may be, for example, a product, a product package, a passport, a banknote, a document, a plastic card, a film or a label.

Suitable base materials for the optically variable elements relating to the invention are materials which can be imprinted as well as exposed by laser-lithography. In particular, these are metallised paints or films, in particular polymer films, e.g. PET, PMMA, PVC, BoPP. Preferably, the metallized paints or films are in a layer composite, in which also other layers are present, e.g. further lacquer layers or foils, in particular polymer foils or adhesive layers, e.g. Acrylic adhesive or hot glue. The base material is preferably label material with at least one adhesive layer. In a further preferred embodiment, the base material is a heat-sealing film containing a metallized layer and a hot-melt adhesive layer. In a further preferred embodiment, the base material is cold seal film containing a metallized layer. The metallization of the paints or films can be produced by vapor deposition, sputtering or by printing with a metal pigment. The metallization may be on the surface of the base material, or it may be internal.

The embossing of the optically variable element according to the invention takes place with a non-individual overall design which is replicated in mass and which may, inter alia, contain all structures known from embossed optically variable elements. This non-individual overall design is called embossing structure.

The overall laser-lithographic exposure design can include both static repeating structures and serial, varying structures, such as e.g. numeric or alphanumeric serial numbers, holograms of such serial numbers or individual graphics. The overall design of the laser lithographic exposure may also include areas that are demetallized or that are rasterized demetallized. The overall design of the laser lithographic exposure is called a laser lithographic structure.

According to the invention, the non-individual embossing structure and the individual laser lithographic structure jointly form at least one optically variable element. Here, the embossed structure and the laser lithographic structure or individual regions thereof may be arranged spatially separated from each other. Furthermore, the embossed structure and the laser lithographic structure or individual regions thereof can be arranged partially or completely overlapping. Furthermore, the embossed structure and the laser lithographic structure or individual regions thereof may be interlaced or interlaced.

By means of the invention, an optically variable element can be produced, which contains structures which can be produced exclusively by embossing as well as structures which can be produced exclusively by laser lithography. By linking the embossed structure with the laser lithographic structure, the individual structures can be graphically and logically combined. The individual structures can complement each other. Due to the possibility of demetallization, which is offered by laser lithography, individual areas of the embossed structure can be individually destroyed.

By combining the embossed structure with the laser lithographic structure, new structures can arise which are not known from conventional optically variable elements not produced according to the invention. For example, the high-resolution demetallization possible in laser lithography can partially or completely destroy structures of the embossed structure. This destruction can be done individually. Since the demetallization is high-resolution, demultivation screening can be used, gradually destroying the embossment structure at these locations. In particular, by the screening a gray course in the demetalization and thus a gray course of the embossed structure can be generated, which is perceived by the human eye as a gradual transition. Such structures can not be produced by conventional methods. Instead of halftoning, a gray value or a gray gradient in the demetallization can also be achieved by targeted modulation of the laser power used during the laser lithographic exposure. Another example of new structures are fine diffractive structures, such as lines or dots, with high diffraction efficiency and arbitrary diffraction angles, which can be individual. In this case, a predetermined diffractive surface of the embossed design is largely demetallized so that only fine structures remain. These leftover metallized fine structures can have a very high diffraction efficiency and arbitrary diffraction angles, since these two factors are determined by the embossment, and they can be individual and highly resolved since they are generated by laser lithography. The fineness of the structures is given by the high resolution of the laser lithography, which is much higher than the resolution of other demetallization methods.

In a preferred embodiment, the laser lithographic exposure can be made precisely to the embossing. This can be done if the embossing takes place first in the production of the optically variable element and then the laser lithography. The fitting accuracy can be ensured by special measures in laser lithography, e.g. by recording features from the pre-embossed structure by means of trigger sensors or cameras. Such features can be integrated as trigger marks specifically to achieve the high accuracy of fit in the embossed design. Since laser lithographs usually have a high accuracy and fidelity in the material transport, the precise alignment of the laser lithographic design to the embossed design does not make any extraordinary demands on the laser lithograph. A fitting accuracy on the order of the resolution of the laser lithograph can be achieved.

If the laser lithography and then the embossing are performed in the manufacturing process, then the embossing can be set precisely to the structures introduced by laser lithography. For this purpose, the position of the laser lithographic structure must first be recorded by means of trigger sensors or cameras, and then the embossing position must be adapted to this position. This can be done by lateral or temporal displacement of the embossing process or by stretching the substrate material.

With a skillful choice of the pre-embossed structure or the laser lithographic structure can be dispensed with a tailor-made alignment of the two structures in a further embodiment of the invention. If e.g. one of the two structures contains repetitive graphical elements, e.g. Guilloches, sine lines, zigzag lines, stripes or dot patterns, due to the repetition of the structures no fit accuracy is necessary. Preference would be given to use embossed structures that require no accuracy of fit to the laser lithographic structure.

The tamper resistant carrier may be sealed or adhered to an object, eg a product, a product package, a pass, a document, a banknote, a plastic card, etc. with the optically variable element. There is also the possibility that the carrier is sealed or glued after production on another label, which in turn itself to an object is glued on. In both cases it is possible to adapt the design of the article or of the further label to the design of the optically variable element. This is particularly useful if portions of the carrier are demetallized. Then, in the demetallized portions, one can see the underlying design which is on the article or on the additional label. This is possible because the demetallized portions become transparent or semitransparent. In this way, the basic design of the object or of the further label is still available for the design in addition to the embossed structure and the laser-lithographic structure. This basic design can be skilfully linked to the embossing patterns and lithographic designs associated with the embossing pattern and the laser lithographic structure. This can be done in addition to a graphical link and a logical link. The basic design can contain both static elements as well as individual elements that can be created eg with an individual printing technique. Individual elements can be numeric or alphanumeric serial numbers, barcodes or individual graphics. The individual parts of the basic design can be logically and graphically linked to the individual parts of the laser-lithographic design. For example, the basic design may include a numeric or alphanumeric serial number that is wholly or partially repeated in the laser lithographic design. The basic design and laser-lithographic design may include numeric or alphanumeric numbers linked together through a database or through mathematical operations. However, static elements of the basic design can also be linked to individual elements of the laser-lithographic design. For example, individual partial areas can be demetallised in the laser-lithographic design, which allow to see certain areas of the basic design. In this way, for example, numbers or color patches of the basic design can be made individually visible.

Fig. 1

einen erfindungsgemäßen streifenförmigen Träger mit geprägtem und lithographischem Design ohne Passgenauigkeit,

Fig. 2

einen streifenförmigen Träger mit einem Prägedesign und einem lithographischen Design mit Passgenauigkeit,

Fig. 3

den Träger gemäß Fig. 1 mit Stanzlinien für einzelne Etiketten,

Fig. 4

den Träger gemäß Fig. 2 mit Stanzlinien für einzelne Etiketten,

Fig. 5

fünf Einzelbeispiele für relative Anordnungen von Prägedesign und lithographischem Design und Stanzlinien,

Fig. 6

ein geprägtes Design, ein lithographisches und ein kombiniertes Graukeildesign,

Fig. 7

ein aus einem geprägten Design und aus einem lithographischen Design gefertigtes feinstrukturiges Design,

Fig. 8

ein aus einem geprägten Design und einem laserlithographischen Design kombiniertes Design,

Fig. 9

ein weiteres Beispiel für ein aus einem geprägten Design und einem laserlithographischen Design kombiniertes Design,

Fig. 10

ein geprägtes Design, ein laserlithograhisches Design, ein kombiniertes Design auf einem Etikett, eine Verpackungsoberfläche und das auf die Verpackungsoberfläche aufgebrachte Etikett,

Fig. 11

ein geprägtes Design, ein laserlithographisches Design, ein kombiniertes Design auf einem Etikett, eine Verpackungsoberfläche und das auf die Verpackungsoberfläche aufgebrachte Etikett.

The invention will be described with reference to exemplary embodiments in eleven figures, in which:

Fig. 1

a strip-shaped carrier according to the invention with an embossed and lithographic design without exact fit,

Fig. 2

a strip-shaped carrier with an embossed design and a lithographic design with a fit,

Fig. 3

the carrier according to Fig. 1 with punched lines for individual labels,

Fig. 4

the carrier according to Fig. 2 with punched lines for individual labels,

Fig. 5

five individual examples for relative arrangements of embossed design and lithographic design and stamped lines,

Fig. 6

an embossed design, a lithographic and a combined gray wedge design,

Fig. 7

a fine-textured design made from an embossed design and lithographic design,

Fig. 8

a design combined with an embossed design and a laser-lithographic design,

Fig. 9

another example of a design combined with an embossed design and a laser-lithographic design,

Fig. 10

an embossed design, a laser lithographic design, a combined design on a label, a packaging surface and the label applied to the packaging surface,

Fig. 11

an embossed design, a laser lithographic design, a combined design on a label, a packaging surface and the label applied to the packaging surface.

Fig. 1 shows a carrier 1 with a metallized layer 2, which has both an embossed design A and a laser lithographic design B.

In the figures, the reference symbols designate, on the one hand, the embossed design A or the laser-lithographic design B, but at the same time those of the designs A, B underlying embossed structure or laser lithographic structure within the metallized layer 2.

The continuous wavy lines and the three parallel lines represent placeholders for static structures of the embossed design A. The serial numbers and the ovals represent placeholders for individual and static structures of the laser-lithographic design B. The placeholders are to be understood symbolically and represent any structures which can be produced with embossing or with laser lithography. The arrangement and the number of symbols are only to be understood as examples.

The embossing and the laser lithographic exposure are not arranged precisely to one another. This can be recognized by the fact that the serial number moves in comparison to the wavy line. Nevertheless, the two designs are linked, because the serial number always comes to lie on the wavy line. The linking is done by a fixed vertical relationship between the two designs.

FIG. 2 shows a carrier with precisely arranged to each other embossed design A and laser lithographic design B. The embossing A and the laser lithographic exposure B are precisely aligned with each other. This can be seen by the fact that the serial number does not migrate compared to the wavy line. Due to the fitting accuracy, both designs can be completely linked together. The linking is done by a fixed horizontal and vertical relationship of the two designs A, B.

Fig. 3 shows the carrier 1 with not exactly matching embossed design A and lithographic design B according to Fig. 1 , 6 punched lines 7 are shown around the individual optical elements. The dotted circles represent the stamping lines 7 for labels or stamp dies for heat-sealing applications and thus the limitation of the optically variable element 6 on the object to which it is applied. The punching line 7 need not be circular, but may have any other shape, such as oval, polygonal, polygonal with rounded corners, etc.

The embossing A and the laser lithographic exposure B are not arranged precisely to one another. However, the laser lithographic exposure B is arranged precisely matching the boundary of the optically variable element 6 and the support 1, so that each optically variable element 6 carries a unique individualization.

Fig. 4 shows a carrier 1, in which the embossing A and the laser lithographic exposure B are precisely to each other and are arranged to delimit the optically variable element 6 and the carrier 1.

In Fig. 5 The dotted circles show punched lines 7 for labels or stamp dies for heat-sealing applications and thus the limitation of the optically variable element 6 in the end product. Various possible arrangements of the structures A, B are shown. Area A represents structures of the embossed design, area B represents structures of the laser-lithographic design. The individual structures A, B can either occur separately from one another, or they can partially or completely overlap. In a design, subregions may overlap and other subareas may not overlap. In addition to the arrangements shown also combed or nested arrangements are possible.

According to Fig. 6 the embossed design consists of an area A, which contains embossed structures. The laser lithographic design consists of a surface B consisting of a high-resolution screened gray wedge 8. The gray wedge 8 is in this example in a gradual transition from non-demetallized to demetallized. As a result, the embossed surface A in the region B is destroyed in a gradual transition, resulting in a gradual leakage of the embossed structures for the human observer. If the embossed structures are diffracting gratings that shimmer in rainbow colors, the iridescence in region B would gradually drain. If the embossed structures are a hologram, the visibility of the hologram in area B would gradually fade. The punching line 7 in turn limits the optically variable element 6.

In this way, a structure is generated which could not be produced by embossing alone or by laser lithography alone.

According to Fig. 7 the embossed design consists of an area A, which contains embossed structures. The laser-lithographic design consists of a surface B in which large areas are demetalized and fine high-resolution lines are left standing. As a result of the embossed area A in area B only fine embossed lines remain. If the embossed structures are diffractive gratings, which shimmer in rainbow colors, so would the fine lines in rainbow colors shimmer. These grids could now be designed so that they could not be generated by the laser lithographic process.

In this way, a structure is generated which could not be produced by embossing alone or by laser lithography alone. Again, the punching line 7 limits the optically variable element. 6

In Fig. 8 the embossed design A consists of a logo, fine guilloches and a full-surface area (hatched). The three areas could consist of different structures, for example, the logo could be designed as a rainbow hologram, the guilloche as a 2D hologram and the full-area area as a refractive or diffractive structure. The laser lithographic design B consists of a square structure, two fine lines, a first serial number and a second, inverse serial number. The square structure could be a computer-generated Fourier hologram with individual content, the two fine lines could be diffraction gratings, the upper serial number could consist of a Fresnel hologram. The lower, inverse serial number demetallizes the outer portion of the serial number.

According to the invention, if the two designs are introduced into the metallized layer 2, the combined design results as the optically variable element 6. This consists of separate regions, each coming from one of the two designs, such as the logo or the Fourier hologram. On the other hand, it consists of partially superimposed structures, such as the guilloches, the lines and the first serial number. Furthermore, it consists of combined structures, such as the inverse laser-lithographed second serial number, which now carries in the numbers the refractive or diffractive structure from the embossing process.

In this way, a structure is generated which could not be produced by embossing alone or by laser lithography alone.

Fig. 9 shows a logical link between the embossed design A and the laser lithographic design B. In the embossed design A are the numbers 1 to 5. According to the final digit of the serial number of the laser-lithographic design B, a field is individually left which repeats the final digit of the serial number. The optically variable element 6 represents the logical link.

Fig. 10 shows first the embossed design A, then the lithographic design B and in the third picture the Fig. 10 the combination of embossed design A and lithographic design B. The third figure represents the optically variable element 6 in the form of a label. The lower sequence of numbers of the laser lithographic design B is transparent. The fourth figure shows the surface 11 of an article, for example, a packaging with a structure shown here wavy. By applying the optically variable element 6 to the surface 11 of the article, the structure of the article located under the transparent region 10 of the optically variable element 6 may shine through.

Fig. 11 shows, similar to Fig. 10 , a logical link between the structure of the surface 11, which is additionally provided here with a serial number. According to the final digit of the serial number, a field 10 is individually demetallised. On the surface 11 of the article, the numbers 1 to 5 are printed statically; through the demetallized field 10, the corresponding number on the surface 11 can then be seen.

LIST OF REFERENCE NUMBERS

1

carrier

2

metallized layer

6

optical element

7

punching lines

8th

wedge

10

demetallised / transparent area

11

surface

A

embossed design

B

laser lithographic design

Claims (14)

1. Forgery-proof carrier (1) having at least one metallized layer (2), into which at least one optically variable element (6) is introduced, and
   the at least one optically variable element (6) has a non-individual embossed structure (A),
   characterized in that
   the at least one optically variable element (6) has an individual laser-lithographic structure (B) with a resolution of less than 20 µm and in that the embossed structure (A) and the laser-lithographic structure (B) are arranged with an accurate fit with respect to one another.
2. Forgery-proof carrier (1) according to Claim 1, characterized in that the resolution is less than 5 µm.
3. Forgery-proof carrier (1) according to Claim 1 or 2,
   characterized in that the embossed structure (A) and the laser-lithographic structure (B) are introduced into the same metallized layer (2).
4. Forgery-proof carrier (1) according to at least one of Claims 1 to 3,
   characterized in that the laser-lithographic structure (B) is at least locally demetallized at least in a subregion (10).
5. Forgery-proof carrier (1) according to Claim 4, characterized in that the subregion (10) is fully demetallized.
6. Forgery-proof carrier (1) according to Claim 4 or 5,
   characterized in that the subregion (10) is demetallized as a raster.
7. Forgery-proof carrier (1) according to Claim 6, characterized in that the rastering of the demetallization increases gradually in the subregions (10).
8. Forgery-proof carrier (1) according to at least one of the preceding claims,
   characterized in that the optically variable element (6) is transparent in a subregion (10).
9. Method for producing a forgery-proof carrier (1) having at least one metallized layer (2), by a non-individual embossed structure (A) being embossed into the metallized layer (2) and an individual laser-lithographic structure (B) being exposed into the metallized layer (2) lithographically by means of a laser,
   the lithographic structure (B) being exposed with a resolution of less than 20 µm,
   at least one optically variable element (6) being formed together by the embossed structure (A) and the lithographic structure (B),
   wherein the laser-lithographic structures (B) and the embossed structures (A) are introduced into the metallized layer (2) with an accurate fit with respect to one another.
10. Method according to Claim 9,
    characterized in that non-individual embossed structures (A) are initially embossed into the metallized layer (2) along the carrier (1), and individual laser-lithographic structures (B) are subsequently exposed into the metallized layer (2).
11. Method according to Claim 9,
    characterized in that individual laser-lithographic structures (B) are initially exposed into the metallized layer (2) along the carrier (1), and non-individual embossed structures (A) are subsequently embossed into the metallized layer (2).
12. Method according to at least one of Claims 9 to 11,
    characterized in that subregions (10) of the lithographic structure (B) are demetallized to the extent of transparency and subregions of the embossed structures (A) are arranged relative to the transparent subregions (10) so that they shine through the transparent subregions (10).
13. Method according to at least one of Claims 9 to 12,
    characterized in that the carrier (1) is separated between the optically variable elements (6), and the optically variable elements (6) are applied onto articles, in particular packaging.
14. Method according to Claim 13,
    characterized in that the optically variable element (6) is provided with transparent subregions (10), and a surface marking of the article shines through the transparent subregions (10).

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