EP1945466B1 - Security element and method for the production thereof - Google Patents

Abstract

Method involves providing substrate (40) with a marking structure with many flat markings(24,26) and with relief structure with many reflex relief elements (22) whereby marking structure and relief structure are combined such that different information are visible from different reflection directions. Optically variable structure (20) having individualized character is produced with contact less procedure or print process on solid printing block. Independent claims are included for the following: (1) Safety element; and (2) Application of safety element.

Description

The invention relates to a security element with an optically variable structure, which contains an individualization identifier, and to a method for producing such a security element. The invention further relates to a data carrier equipped with such a security element.

For protection against counterfeiting, in particular with color copying machines or comparable reproduction methods, data carriers, such as banknotes, securities, certificates, vouchers, checks, high-quality admission tickets, but also other counterfeit-endangered papers, such as credit cards, passports and other identity documents, as well as product security elements, such as labels, Seals and packaging, equipped with optically variable security elements. The protection against counterfeiting is primarily based on the fact that the visually variable effects are visually simple and clear to the human observer, but that they can not be imitated with today's known reproduction devices, since these always reproduce the optically variable elements only from one viewing direction.

At the same time such data carriers should often contain an individualization or personalization, such as a numbering with banknotes or personal data or a photograph with identity documents. These individual components of the volume compete with other security elements for space on the volume.

As optically variable security elements for data carriers are for example from the document EP 0 801 604 B1 Relief structures known with tilting effect. These security elements essentially consist of an embossing grid certain spatial frequency, which is combined with a flat coating grid of the same spatial frequency so that at least parts of the coating grid are visible when viewed vertically, but hidden under oblique viewing under a predetermined viewing direction. When alternately vertical and oblique viewing so creates a tilting effect.

However, the printing and embossing methods used as standard do not allow individual information for each individual use in the tilted image. On the other hand, if the standard method for individualizing bank notes or value prints, the lettering in the book or high-pressure, used, so a previously introduced imprint would be partially destroyed. However, the printing order can only be reversed with difficulty, since the customization is generally used as the last print run.

Furthermore, since the grid structures are fine line or dot patterns, effect color, which due to its pigment size can only be applied in relatively coarse screen printing, can generally not be used as a flat print.

Another disadvantage is that the flat pressure and the corresponding relief structure must be produced in two different passes, and thereby result Passerschwankungen that can not make the tipping effect or only weak. Therefore, the tilting security elements are usually arranged several times and slightly offset from each other on a disk to ensure that the tilting effect occurs well visible in at least one of the elements.

From the publication DE 199 47 425 A1 is a method for coating existing relief structures is known in which the relief material is coated by means of color droplets or pigments each at an oblique angle, so that the flanks are each colored with a particular color. However, this method requires an oblique orientation of the Farbtröpfchen- or pigment stream relative to the relief structure, preferably in an evacuated or over-pressurized area, which makes fast mass production difficult with conventional printing machines. Although the method allows a later, but no individual marking of the disk.

DE 8529297 U1 also shows a method of making a security element.

On this basis, the invention has for its object to provide a generic security element that avoids the disadvantages of the prior art. In particular, the security element individualization and optically variable effect to combine in an advantageous manner with each other and can be produced even at the required in securities printing high processing speeds.

This object is achieved by the manufacturing method and the security element having the features of the independent claims. Further developments of the invention are the subject of the dependent claims.

1. a) Versehen eines Substrats mit einer Markierungsstruktur mit einer Mehrzahl flacher Markierungen; und
2. b) Versehen des Substrats mit einer Reliefstruktur mit einer Mehrzahl erhabener Reliefelemente.

According to the invention, a method for producing a security element with an optically variable structure which contains an individualization indicator comprises the method steps:

1. a) providing a substrate having a marking structure with a plurality of flat marks; and
2. b) providing the substrate with a relief structure having a plurality of raised relief elements.

In this case, the marking structure and the relief structure are combined so that different information is visible from different viewing directions and the individualization indicator is generated in at least one of the steps a) or b) with a non-contact method or a printing method without a fixed printing forme.

Non-solid printing form printing processes are also referred to as non-impact printing processes or NIP processes. The term "non-impact" is based on a distinction from earlier customary "impact printers" in which a type or needles by impact has brought the information on the paper. Such systems have in many cases been replaced by electrophotographic methods in which the information is transmitted via a laser contactlessly to an intermediate carrier, the latent charge image stored there is colored with a toner and then transferred to the paper. In the case of NIP processes as well, there is contact between the information color carrier and the paper during printing, but the information is not transmitted by impact (see Handbuch der Printmedien, ed. Helmut Kipphan, Springer, 2000, p. 709) ). In particular, electrophotography, ionography, magnetography, ink-jet methods and thermography are counted among the printing methods without a fixed printing form (loc. Cit., P.711).

In a first advantageous embodiment, the marking structure and the relief structure are produced with the same method in one step. According to another, likewise advantageous embodiment, marking structure and relief structure are produced in separate working steps, wherein the marking structure can be generated before or after the relief structure.

In all embodiments, a space-saving connection of security element and individualization of a data carrier are achieved as advantages, as well as additional security through the possibility of correspondence of security element and other customizations, for example, the connection of a tilting element with a numbering on a banknote.

If the flat markings are produced for example by laser color removal from preprinted surfaces, it is also possible to use effect colors which, owing to their pigment size, can only be applied in screen printing with a relatively high mesh size and therefore do not permit fine resolution in the required spatial frequency in the printing. In this way, for example, color and information tilt effects can be combined with each other.

In particular, if the flat marks and the relief elements of the relief structure are applied in rasters of the same spatial frequency, it is not necessary to maintain an oblique angle between the two generating steps.

By creating the reliefs substantially in the substrate of the data carrier and the problem of abrasion of ink layers during use is prevented, as for example in your from the publication DE 692 09185 T2 known methods can occur. Since the relief is essentially in the substrate, it has a better durability against other mechanical or chemical loads.

If the marking structure and the relief structure are generated with the same device in a single operation, there is also no registration problem between relief information and marking information. As a result, it can be dispensed with repeatedly representing the resulting tilting information.

The substrate of the data carrier is in particular a coated or uncoated cotton paper or a coated or uncoated plastic film, in particular based on PVC, polycarbonate or PET.

According to a preferred embodiment of the method, the relief structure is embossed into the substrate. The embossing can be done for example with a stamping tool or in intaglio. According to another, likewise preferred embodiment, the substrate is provided with the relief structure by the action of a laser beam. The laser parameters for generating the relief structure are tuned in a conventional manner to the composition and the properties of the substrate, such as in the publications DE 102 47 591 A1 or DE 32 13 315 A1 described, the disclosure of which is included in the present application in this respect.

The relief structure is advantageously designed in the form of a grid, preferably a grid with a constant spatial frequency. The raised grid elements form the "grid points" of the grid. It is understood that the term "halftone dot" is understood in the usual sense in printing technology and does not mean an expansion-free point in the mathematical sense. Possible raster arrangements include rasters with a constant period (constant dot size, constant dot pitch), amplitude modulated rasters (variable dot size, constant dot pitch), frequency modulated Raster (constant point size, variable dot pitch) and non-periodic higher order grids, as described in the above-mentioned manual of print media on pages 44 ff. In addition to two-dimensional grids, one-dimensional grids (line grids) are also possible. The "grid points" are formed in this case by linear grid elements.

In an advantageous variant of the invention, the substrate is provided with the marking structure by the action of a laser beam. The marking structure can be introduced into a substrate body, such as a cotton paper or a plastic film, or into a layer applied to the substrate body. According to another, likewise advantageous variant of the invention, the marking structure is printed on the substrate. The marking structure can be applied, for example, by the ink-jet method or with a low-pressure digital printing method. In other embodiments, the marking structure is advantageously produced in planographic printing, such as in the offset process, in high pressure, such as in letterpress or flexographic printing, in screen printing or a thermographic process, such as in the thermal transfer process.

Like the relief structure, the marking structure is advantageously designed in the form of a grid, preferably in the form of a grid with a constant spatial frequency, the flat markings forming the "grid points" of the grid. The possible grid arrangements are the same as described above in connection with the relief grids.

The rasters of relief structure and marking structure preferably have the same spatial frequency. However, it is also possible the relief structure and form the marking structure to produce beat or moiré effects with slightly different spatial frequencies.

The customization tag preferably comprises letters, numbers, or a symbol code, such as a stroke or matrix code.

The substrate and / or the surface of the security element may contain further security substances that are activated, exposed, covered, partially destroyed or removed in at least one of the steps a) or b).

The invention also encompasses a security element with an optically variable structure which contains a marking structure with a plurality of flat markings and a relief structure with a plurality of raised relief elements, wherein the marking structure and the relief structure are combined in such a way that different information is visible from different viewing directions. The marking structure and / or the relief structure is provided with an individualization identifier, which is generated by a non-contact method or a printing method without a fixed printing plate.

The relief elements of the relief structure and / or the flat markings of the marking structure are advantageously arranged in the form of a grid, preferably in the form of a grid with a constant spatial frequency. As mentioned above, the rasters of the relief structure and the marking structure can have the same spatial frequency or, for the generation of beat or moiré effects, slightly different spatial frequencies.

The flat markings are expediently arranged at least partially on flanks of the relief elements, wherein a relief element and an on at least one of its flanks arranged flat marking together form a structural element. The flat markers advantageously have at least one colored surface. Often it will be useful to form the flat markings with several colored surfaces, which are at least partially arranged on different flanks of the relief elements, so that the viewer wins different color impressions from different viewing directions.

In an advantageous development of the invention, the optically variable structure contains a plurality of structural elements (ie relief elements with flat markings arranged on at least one of their flanks), which represent a multicolored image motif whose visual impression varies when the viewing angle is changed.

The individualization identifier may include letters, numbers or a symbol code, such as a bar code or matrix code. It can also have several components that are recognizable only at different viewing angles. For example, the customization flag may represent a digit that appears in a different color depending on the viewing angles, or it may include two or more different icons, each recognizable from different directions.

The relief structure and the marking structure can be arranged on a single-layered or multi-layered substrate, or on a substrate which is mono- or multilayer-coated, printed, glued, laminated or laminated.

The substrate and / or the surface of the security element can also have further, in particular machine-readable security features, in order to further increase the security against counterfeiting.

In a further development of the invention, the marking structure and the relief structure are combined with one or more further layers, which represent a pattern or image that can be visually recognized when viewed vertically.

The raised relief elements of the relief structure can advantageously also be formed tactile detectable. The height of this tactile marking above the surface can be widely varied by the choice of laser parameters, substrate material, and the relative speed of laser beam and substrate in laser marking. Typically, a height between 30 microns and about 100 microns is chosen.

The relief structure may in particular contain a plurality of non-linear relief elements, wherein advantageously at least a portion of the non-linear relief elements substantially the shape of a tetrahedron, a spherical portion, a truncated pyramid, a truncated cone, a cylindrical portion, a Torusabschnitts, an oval, a drop or a pyramid.

In order to compensate for register fluctuations, the relief structure can be subdivided into partial regions in which different partial relief structures are arranged. In particular, the partial relief structures can each form a raster of the same raster width and the rasters of the partial relief structures in at least two adjoining partial areas by a fraction of the Grid width, in particular by about one-third of the grid width, be arranged offset.

The invention further includes a data carrier, in particular a value document, such as a banknote, identity card or the like, with a security element of the type described above.

Further embodiments and advantages of the invention are explained below with reference to the figures. For better clarity, a scale and proportioned representation is omitted in the figures.

Fig.1

eine schematische Darstellung einer Banknote mit einem Si- cherheitselement nach einem Ausführungsbeispiel der Erfin- dung,

Fig. 2

einen Schnitt entlang der Linie II-II der Fig.1,

Fig. 3

einen Ausschnitt nur der Reliefstruktur des Sicherheitselements der Fig. 1 in Aufsicht,

Fig. 4

einen Ausschnitt nur der Markierungsstruktur des Sicherheits- elements der Fig.1 in Aufsicht,

Fig. 5

die Kombination der Reliefstruktur der Fig. 3 und der Markie- rungsstruktur der Fig. 4,

Fig. 6

eine Aufsicht auf ein Sicherheitselement nach einem Ausfüh- rungsbeispiel der Erfindung in schematischer Darstellung,

Fig. 7

eine Darstellung wie in Fig. 5 für ein Sicherheitselement nach einem weiteren Ausführungsbeispiel der Erfindung,

Fig. 8

einen Ausschnitt nur der Markierungsstruktur eines Sicher- heitselements nach einem weiteren Ausführungsbeispiel der Erfindung in Aufsicht,

Fig. 9

einen Ausschnitt nur der Reliefstruktur des Sicherheitsele- ments der Fig. 8,

Fig. 10

die Kombination der Markierungsstruktur der Fig. 8 und der Reliefstruktur der Fig. 9,

Fig.11

in (a) und (b) schematische Aufsichten auf die Grundraster von Sicherheitselementen nach weiteren Ausführungsbeispielen der Erfindung,

Fig. 12

eine schematische Aufsicht auf das Grundraster eines weiteren erfindungsgemäßen Sicherheitselements,

Fig. 13

ein Sicherheitselement nach noch einem weiteren Ausfüh- rungsbeispiel der Erfindung, wobei (a) den Bildeindruck bei senkrechter Betrachtung (b) zeigt, und (c) den Bildeindruck bei Betrachtung aus schrägem Winkel (d) darstellt, und

Fig. 14

eine Weiterentwicklung des Sicherheitselements von Fig. 12.

Show it:

Fig.1

1 a schematic representation of a banknote with a security element according to an exemplary embodiment of the invention,

Fig. 2

a section along the line II-II of Fig.1 .

Fig. 3

a section only of the relief structure of the security element of Fig. 1 in supervision,

Fig. 4

a section only of the marking structure of the security element of Fig.1 in supervision,

Fig. 5

the combination of the relief structure of Fig. 3 and the marking structure of the Fig. 4 .

Fig. 6

a plan view of a security element according to an embodiment of the invention in a schematic representation,

Fig. 7

a representation like in Fig. 5 for a security element according to a further exemplary embodiment of the invention,

Fig. 8

a detail of only the marking structure of a security element according to a further embodiment of the invention in supervision,

Fig. 9

a section only of the relief structure of the security element of Fig. 8 .

Fig. 10

the combination of the marking structure of the Fig. 8 and the relief structure of Fig. 9 .

Figure 11

in (a) and (b) are schematic plan views of the basic grid of security elements according to further embodiments of the invention,

Fig. 12

a schematic plan view of the basic grid of another security element according to the invention,

Fig. 13

a security element according to yet another embodiment of the invention, wherein (a) shows the image impression when viewed perpendicularly (b), and (c) represents the image impression when viewed from an oblique angle (d), and

Fig. 14

an evolution of the security element of Fig. 12 ,

The invention will now be explained using the example of a banknote. Fig. 1 shows to a banknote 10 with a security element 12 according to the invention, which is arranged in the print image area 14 of the banknote. The security element 12 contains an optically variable structure which presents different information to the viewer under different viewing directions and thus exhibits a tilting effect. Such security elements are often used in banknotes and other monetary documents, since the tilting effect can be easily visually recognized and checked by the viewer, but he just because of the directional dependence of the visual impression with today's copy machines that reflect the optically variable structure from only one line of sight, can not be reproduced.

The optically variable structure of the security element 12 also has an individualization identifier, which is characteristic for the individual data carrier. For example, banknotes can be all or part of the serial number; for identity documents, the individualization can contain personal data or a portrait. In order to be able to integrate this individualization code in the optically variable structure, this is, as explained in detail below, generated in at least one of the steps for producing the optically variable structure with a non-contact method or a printing method without fixed printing form.

First, the basic structure of the optically variable structure of the security element 12 will be described with reference to FIGS FIGS. 2 to 5 explained in more detail, wherein Fig. 2 a schematic sectional view taken along the line II-II of Fig. 1 shows. Fig. 3 shows a section of only the relief structure of the security element 12 in supervision, Fig. 4 a section of the marking structure only of the security element 12 in supervision and Fig. 5 shows the combination of the relief structure of Fig. 3 with the marking structure of Fig. 4 ,

As best in the presentation of Fig. 2 To recognize, the optically variable structure 20 on a plurality of raised relief elements 22, which can be produced for example by embossing the banknote 10. If the banknote is mechanically deformed with an embossing tool, the underside of the banknote shows corresponding negative deformations, which, however, are not essential in the context of the present invention and are therefore not shown in the figures. If the relief elements are produced in a different way, for example by the action of a laser beam on the substrate material, then as a rule no corresponding deformations occur on the banknote backside.

The optically variable structure 20 further includes a marking structure with a plurality of flat marks 24, 26 which are arranged on different flanks of the relief elements 22 and thus give the security element a different appearance depending on the viewing direction.

The FIGS. 3 and 4 show for illustrative purposes a section of the relief structure and the marking structure in a plan view, wherein the dotted-line square grid serves only for a clearer representation. Both the relief elements 22 and the flat markings 24, 26 are arranged in a grid with a constant spatial frequency whose horizontal and vertical grid width are given by values x and y, respectively. In the exemplary embodiment, a square grid with x = y is shown.

As in Fig. 4 To recognize, the spatial frequency of the marking structure is related to an imaginary reference point 28 in the center of each grid square. The flat markings 24, 26 themselves can occupy different positions within the grid squares in order to come to lie on different flanks of the relief elements. If, for example, the marking structure of the Fig. 4 with the relief structure of Fig. 3 combined, the flat markings 24 and 26 come to rest on opposite flanks of the relief elements 22, as in FIGS Figures 2 and 5 shown. In each case, a relief element 22, together with the flat marking 24 or 26 arranged on one of its flanks, forms a structural element 32, wherein the structural elements 32, as smallest units, form the pixels of the rasterized information represented overall by the optically variable structure.

When viewed from a first viewing direction 30 (FIG. Fig. 2 Above all, the markings 24 determine the image impression, while the markings 26 are hardly or not at all visible. By contrast, when the structure is viewed from an opposite viewing direction, the markers 26 in particular determine the image impression, while the markings 24 contribute little or not at all. By means of a suitable arrangement of the markings 24 and 26, an individualization mark with a tilting effect can thus be integrated into the optically variable structure 20 of the security element 12.

Hereinafter, some concrete embodiments will be described, wherein first on the basis of FIGS. 2 to 10 Embodiments are described in which the relief structure and the marking structure are generated in separate steps.

In a first embodiment, now mainly with reference to the representation of Figures 2 and 6 is explained in more detail, is the individual information by color change or color removal in relief structures introduced, which were embossed with or without flat color layers in substrates.

For this purpose, a laser-absorbing, for example, black ink layer 42 is first printed on a substrate 40, which can be locally removed or modified in a later step by the action of laser radiation, so that a local color change occurs at the location of the laser application.

Relief structures are then embossed in the printed substrate, in the exemplary embodiment in the form of a regular knobbly relief 22, as in FIG Figures 2 and 3 The printed and embossed substrate is then exposed to laser radiation in accordance with a predetermined dot screen pattern to produce the flat markings, the reference dots of the dot screen pattern having the same screen widths x and y as the dimpled relief 22.

In the simplest case, the black color layer 42 is removed locally by the laser application, so that at the marked locations 22, 24 the white background layer of the substrate emerges, as in FIG Fig. 2 shown. Under the laser-absorbing ink layer 42, a different colored, non-absorbing ink layer can be arranged, which is exposed by the laser exposure locally. In further embodiments, a local color change in the color layer 42 can be induced by the .Laser radiation without erosion. For example, the color layer may comprise a color mixture with a mixture component absorbing the laser radiation and a mixture component transparent to the laser radiation, wherein the absorbing mixture component bleaches, evaporates under the action of the laser radiation, in its reflection properties can be changed or converted by a chemical reaction in a material with different optical properties, so that visually recognizable flat marks arise.

It will be appreciated that the flat markings of the dot screen pattern are not all located at the reference point to represent information. Rather, as in Fig. 6 a first subgroup 46 of the flat marks from the reference point by (+ x / 4, + y / 4), so moved to the top right, while a second subgroup 48 of the flat marks from the reference point to (-x / 4, - y / 4), that is shifted to the lower left. The first and second subgroups of flat markings thus come to rest on opposite flanks of the relief elements 22. The clearer presentation is in Fig. 6 the relief elements 22 printed with the black color layer 42 are unfilled, while the flat markings 22, 24 in which the color coating has been removed, and which thus appear light to the viewer, are shown diagrammatically in FIG Fig. 6 are shown filled.

The first and second subgroups of flat marks 46, 48 together form the information that is written to the optically variable structure by the laser as individual indicia. In the embodiment of Fig. 6 the two subgroups 46, 48 together form the number "5". When viewed from the direction 50, the observer mainly looks at the bright markings 26 of the first subgroup 46, while the markings 24 of the second subgroup 48 lie on the side of the relief elements 22 facing away from the observer. The numeral "5" therefore appears dark against a light background from this direction.

On the other hand, when viewing from direction 52, the viewer is looking at the bright markings 24 of the second subgroup 48, while the markings 26 of the first subgroup 46 lie on the side of the relief elements 22 facing away from the observer, so that the numeral "5" from direction 52 is bright a dark background appears. This contrast change occurs noticeably when tilting the security element. It is understood that depending on the shape of the relief elements 22 and the relative arrangement of the markers 24, 26 to the reference point 28, other excellent viewing directions can be selected.

Since, when registering a printing press, it must be expected that the lasered markings 24, 26 can also land on the center of the knobs 22 and in the valley between the knobs 22 and thus not produce a clearly visible tilting effect, several similar fields with relief structures can be created , in which the lasered dot matrix is shifted in each case by 1/3 of the screen width, for example. Equally, the pre-embossed knob pattern could also have these shifts in different fields.

Attachment of the flat mark 24, 26 in place can be assisted by coating the substrate 40 to match the relief structure 22 so that, for example, certain spots will take on color while others will not. If the marking is carried out by means of laser marking, the coating can advantageously be arranged such that certain points absorb laser radiation at a certain parameter set (for example from energy and / or wavelength and / or pulse length) and thus undergo a color change, but others only at one other parameter set.

Possible register problems can also be reduced by determining the position of the given grid by means of suitable metrological measures. For this purpose, for example, register marks with the relief-giving operation can be introduced, which are subsequently read out before the application of the flat markings 24, 26 by suitable sensors, or industrial image processing can be used to determine the position of the predetermined relief 22. Since non-contact and / or digital printing methods can work without a fixed original, not only the content but also the position of the flat marking can be determined shortly before application and thus adapted to the actual position of the relief.

Likewise, the information to be applied may be based on data which is read from it during the transport of the substrate 40, and then applied corresponding to this information. Thus, for example, the serial number of a banknote can be read before lasering and then the final digit can be lasered into the nubs 22 as information. The same applies, for example, for personalization data of ID documents that are first read and then z. B. be partially incorporated into a tilted image.

The information can also arise from the fact that the lasered dots have different size or shape or are pulled together into lines. It can arise, for example, by color removal, color lightening or a change in the color impression, all of these variants being subsumed under the term "color change" in the present description.

In place of the laser can also be the ink-jet process or another digital printing process occur that works with so little pressure that the relief structures are not destroyed. Normally, this creates dark structures on a bright, embossed substrate.

The sequence of operations can also be reversed. Typically, however, the sequence described is preferred, since then the individualization takes place as the last printing process.

The relief elements 22 may also be provided at two or more different locations with markings 24, 26, as in the embodiment of Fig. 7 shown. In this case, depending on the perspective different pictures. For example, a first symbol, such as a number, can be composed of marker points 24, which appear on the bottom left of the relief elements 22. A second symbol, such as a letter, is composed of marker points 26, which appear at the top right of the relief elements 22. Depending on the viewing angle, the first or second symbol is then perceived.

The procedure for a line relief, ie a relief structure with linear relief elements, proceeds analogously: In the pre-printed color, a line pattern is formed which has parallel flanks pointing in opposite directions. The flat markers are then inserted so that lines emerge that land on the flanks. Different information can be represented, for example, by shifting the line grid by half the distance of the pre-embossed relief grid.

The preprinted ink may also be made as a screen printing ink containing feature or effect pigments. It is essential for the present embodiment only that this color can be edited using the laser. In this way, the necessary resolution for tilting elements can be achieved, even if pressure screens with a large mesh size must be used for the printing in order to take account of the larger pigment size.

Another possibility for introducing the individual information into the optically variable structure is to introduce the relief structures into contactlessly already provided with flat mark substrates, as now with reference to the FIGS. 8 to 10 described.

First, in these embodiments, a substrate is provided at regular intervals of a certain spatial frequency with flat marks, for example in the form of different colored circles 60, as in Fig. 8 shown. For this purpose, all conventional printing methods of suitable resolution can be used.

Then, a relief structure with raised relief elements 62, 64 is produced in the substrate by application of laser radiation, as in FIG Fig. 9 shown. In the exemplary embodiment, the grid widths x, y of the relief structure are selected to be identical to the grid widths x, y of the marking structure. The laser parameters for generating the relief structure are matched to the composition and the properties of the substrate, wherein for details of the known methods on the documents DE 102 47 591 A1 or DE 32 13 315 A1 is referenced. In addition, the laser parameters and the properties of the inks used for the flat markings are matched to one another such that the printing inks used do not absorb the laser radiation or absorb them only slightly, so that they are not or only slightly changed or removed by the laser radiation.

In order to display the information, the relief structure in this embodiment, a first and second subset of relief elements 62 and 64, which are offset from each other by half a grid. Depending on which of the colored circles 60 land where on the relief elements 62, 64, the observer gets different color impressions from different viewing directions, as is the case with Figure 10 illustrated. Similar to the embodiment of the FIGS. 3 to 5 For example, the two subgroups of the relief elements 62, 64 may represent the shape of the desired individualization mark, for example a number, a letter or another symbol. The excerpts of the FIGS. 8 to 10 show, for example, a part of an optically color-variable representation of a number "5".

In this embodiment as well, it must be expected that with normal registration using a printing press that the printed dots 60 can also land on the middle of the studs 64, 66 and in the valley between the studs and thus no clearly visible tilting effect arises. Therefore, a plurality of identical or similar fields can be created in which the lasered knob pattern, for example, each shifted by 1/3 of the screen widths in different directions. Similarly, the pre-printed dot matrix 60 could have these shifts in different fields.

The inscribed individual information can also arise because the lasered knobs, for example, have different size or shape or z. As drawn into strokes or "worms" become. The pre-printed dots 60 can also be provided with nubs at two or more different locations, so that different images are produced depending on the viewing angle. So z. For example, a number may be composed of pimples, which appear below the dots in the bottom left corner, another one made of pimples, which appear at the top right. Depending on the angle of view, one or the other number is then perceived.

The procedure for a stroke relief is similar again: Here, a bar pattern is tangibly introduced into the pre-printed lines, having parallel flanks pointing in opposite directions. The flat marks are then on the flanks of this relief. Different information is displayed by the relief z. B. is shifted by half the distance of the pre-printed line grid.

The individual information can be generated in further embodiments of the invention in the form of a color or relief change to existing tilt images. In this case, first of all a conventional tilt image is produced according to the prior art and the individualization identifier is then determined by a contactless and / or a digital method in the form of an information-containing marking structure (such as in US Pat Fig. 2 to 7 ) or in the form of an informative relief structure (such as in Fig. 8 to 10 ) generated. This creates additional information within the specified tilting image that generates its own tilting effect.

In principle, the inscribed, in particular lasered, information can also be produced here by color change (color removal, lightening or a change in the color impression). The information can also be thereby arise that other shapes are lasered as dots or dashes or different sizes or line weights are used.

A variant of the invention arises when one or more further layers are pre-printed in front of the information-carrying printing passes. Then, either this layer can be changed while affecting overlying layers, or it can be exposed, depending on which of the layers is absorbent. If there are more layers underneath, they can be uncovered. One of the layers may also contain a feature color that can be seen or detected only with engineering tools and is affected or exposed by the lasering.

In the other, now with reference to the FIGS. 11 to 14 described embodiments, the relief structure and the marking structure by means of the same non-contact method, in particular by means of laser application generated, so that registration problems are inherently avoided. The individual information can be represented by the relief structure or the marking structure.

In the case of first exemplary embodiments of this variant of the invention, a relief structure is produced in each case by subjecting coated substrates to a relief structure. The coating is chosen so that a color change (color removal, lightening, bleaching) can be generated by the laser radiation in the same operation.

In the coated substrate first the relief structures and then the flat markings or vice versa can be introduced, depending on how it appears technically advantageous. Mostly it will be to bring in the flat marks first. The arrangement of the two parts of the resulting tilting image can match the figures and examples described above, so that the flat markings consist of points that appear on the flanks relief bumps forming.

The information content can be either in the arrangement of the flat markings or in the arrangement of the relief elements. Also in this variant of the invention, it is possible to make various information from different angles visible by the flat marks come to lie for different information on different points of the relief. Also effect colors can be used as a background.

The basic grid can be aligned horizontally and vertically, as in Fig. 11 (a) in which the reference numeral 70 denotes the relief elements and the reference numeral 72 denotes the flat markings. The grid width can be, for example, x = y = 0.5 mm. For the designs of the 11 (a) For example, the pattern must be flipped "over corner" to view the different states as indicated by arrows 74. If the pattern is to be tilted vertically from top to bottom, as the viewer might involuntarily say, it is an advantage to arrange the basic grid rotated by 45 °, as in Figure 11 (b) shown. The arrangement of the information "on the corner", ie on the diagonal, has the advantage that more space is available for the information to be displayed.

Of course, other regular arrangements of the relief elements 70 and the flat markings 72 are possible, in particular those in which the grid is stretched or compressed in one of the two main directions.

It may also be advantageous to introduce into the pre-printed background by fine structures or slightly different colors a graphic, an image or a pattern that is visible in the plan and distract the eye of the observer from the information hidden in the tilting image. Only when tilting then the introduced customization information is clear.

Since the production of the relief elements by laser is accompanied by a removal of the color, the relief element expands each of the brightened spot. It is also possible to use auxiliaries in the substrate which promote the formation of relief; in this case, a lower energy will be used for this, resulting in a less extensive color removal, so that the area used for the flat marking receives a greater share of the total color removal and the information contained in the flat marking is more visible.

The height, the extent and the brightness of the relief elements 70 and the extent and the brightness of the flat markings 72 can also be varied such that a raster image is produced in the manner of an autotypic raster (i.e., the same spacing of the raster points at different point sizes). In this way, the observer in supervision will only perceive the raster image, but when tilting, there will be further information.

Also with another, with respect to Fig. 12 explained embodiment can be achieved that the inscribed individual information in supervision initially does not appear or difficult to see. For this purpose, the laser parameters are selected so that the relief structure 70 and the flat marking structure in the coated substrate have the same or at least a similar gray value. Then, in certain areas 76, the arrangement of the relief elements 70 and the flat markings 72 interchanged. At an oblique angle, information can be seen that, depending on the angle of view and light, appears bright on a dark background or dark on a light background.

The latter two approaches can also be combined with each other, as now with reference to Fig. 13 explained. In the portrait 80 shown there, the relief elements and the flat markings are each arranged in a constant grid. The different impression of brightness arises only through a variation of height, extent and brightness of the relief elements and of the extent and brightness of the flat markings. In the area 82, whose outline represents individual information, in the exemplary embodiment the figure "5", the arrangement of the relief elements and the flat markings is interchanged, as in FIG Fig. 12 shown.

Looking at the portrait 80 from the vertical viewing direction 84 (FIG. Fig. 13 (b) ), this interchanging can not be recognized, since the exchanged and unexchanged arrangements produce the same brightness impression from this viewing direction. The image impression thus corresponds to the representation of Figure 13 (a) , On the other hand, when the portrait 80 is tilted and viewed from an oblique angle 86 ( Fig. 13 (d) ), so the area 82 depending on the viewing direction highlights bright or dark from its surroundings and the registered individual information is recognizable, as in Fig. 13 (c) shown schematically.

The described embodiments can be extended such that the optically variable structure contains additional information which can be recognized, for example, in the horizontal tilting direction. Figure 14 shows an extension of the embodiment of Fig. 12 So a relief structure with relief elements 70 and a marking structure with flat markings 72, wherein the arrangement of the relief elements 70 and the flat markings 72 in certain areas 76 is interchanged. In the embodiment of the Fig. 14 perpendicular to the connecting line of the relief elements and the flat markings additional markings 78 are provided which may contain further information.

This further information lies outside the flanks of the relief elements 70 and is therefore easy to see even when viewed vertically. The further information can therefore be used to display image content, especially in the top view, which initially distract the eye of the observer from the actual tipping information.

In other embodiments, the additional markers 78 may also be attached only at certain locations or reinforced at certain locations. It is also possible to arrange the additional markings 78 and the tilting patterns 70, 72 in such a way that they complement each other.

The additional markers 78 can also be used to lighten the overall appearance of a security element or to further match the gray levels of flat markers and relief elements. For this purpose, size and color removal of these additional marks can be adjusted accordingly.

The contrast arising when tilting can be improved by adjusting the area ratio of the light markings (flat and relief) to the brightness impression of the total area. For a technical description and comparison measurement, the brightness is described in grayscale. The so-called simple contrast is thus the ratio of gray scale the bright points (G _h ) to the average gray scale of the total area (G _m ) formed: $$\mathrm{K}\mathrm{=}{\mathrm{G}}_{\mathrm{H}}\mathrm{/}{\mathrm{G}}_{\mathrm{m}}\mathrm{,}$$

As you can see now this ratio is better, the darker the overall impression of the surface and thus the smaller G _m.

gegeben ist, und bei den hier vorliegenden Grauwerten auch für die Modulation $${\mathrm{K}}_{\mathrm{M}}\mathrm{=}\left({\mathrm{G}}_{\mathrm{h}}\mathrm{-}{\mathrm{G}}_{\mathrm{m}}\right)\mathrm{/}\left({\mathrm{G}}_{\mathrm{h}}\mathrm{+}{\mathrm{G}}_{\mathrm{m}}\right)\mathrm{.}$$

The same applies to the so-called Weber contrast, which is due to $${\mathrm{K}}_{\mathrm{w}}\mathrm{=}\left({\mathrm{G}}_{\mathrm{H}}\mathrm{-}{\mathrm{G}}_{\mathrm{m}}\right)\mathrm{/}{\mathrm{G}}_{\mathrm{m}}$$

is given, and in the case of the gray values present here also for the modulation $${\mathrm{K}}_{\mathrm{M}}\mathrm{=}\left({\mathrm{G}}_{\mathrm{H}}\mathrm{-}{\mathrm{G}}_{\mathrm{m}}\right)\mathrm{/}\left({\mathrm{G}}_{\mathrm{H}}\mathrm{+}{\mathrm{G}}_{\mathrm{m}}\right)\mathrm{,}$$

It is therefore advantageous to distribute the individual marking points in a lower spatial frequency, as this reduces the brightness impression of the total area. Nevertheless, when optimizing the contrast, care must also be taken to ensure that sufficient coverage is required when tilting for the brighter image components and that the image context is not lost due to pixels that are too far apart from each other. To accommodate these requirements, preferred screen rulings are between about 0.4 mm and 1.2 mm, with the range between 0.5 mm and 1 mm being particularly preferred.

In the same way, the overall brightness can be lowered by using the darkest possible shade with the highest possible saturation for the background color. It is particularly advantageous to use the method of intaglio printing used in security printing, which due to the high layer thicknesses allows good saturation. Since it is problematic with conventionally produced intaglio printing plates to print surfaces, methods are preferred which allow a small-scale structuring even of deeper surfaces and thus produce defined inking patterns, as for example in the documents DE 100 44 711 A1 or DE 198 45 440 A1 described, the disclosure of which is included in the present application in this respect.

Instead of coating the substrate with a laser-sensitive layer, it is also possible to use substrates which respond to the laser application with blackening or coloring. Also in this variant of the invention, the order of the generation of the two parts relief and flat marking is free. The arrangement of the two parts, for example, again correspond to the illustrations shown above.

The substrate may be admixed with additives that assist in the production of relieves. At the same time dyes or pigments can be used with great advantage, which can appear at different power or energy density of the laser a different color change, or those that do so depending on other laser parameters, such as wavelength or pulse duration, etc.

Also advantageous are substrates that react to different laser power or energy densities even without special additives with different color impressions. For example, plastics can be used for this, into which relief structures are introduced at high power or energy density by forming bubbles in the substrate by expansion of gases. These generally have a whitish color impression due to light scattering. A lesser-energy, however, flat marking results in a color change to darker shades. The substrates are mainly PVC, polycarbonate or PET variants.

The combination of the two process steps described above is possible. For example, in a substrate coated with laser-absorbing pigments and / or dyes, a flat mark may first be lasered to remove the ink. The flat mark also contains the location of the relief structure. Then the relief structure is lasered into the exposed substrate, where it again produces a blackening or a color change.

Claims (31)

1. A method for manufacturing a security element having an optically variable pattern that includes an individualizing mark, having the method steps:

   a) providing a substrate with a marking pattern having a plurality of flat markings;

   b) providing the substrate with a relief pattern having a plurality of raised relief elements,

   the flat markings being at least partially disposed on sides of the relief elements and the marking pattern and the relief pattern being combined in such a way that different pieces of information are visible from different viewing directions, and
   the individualizing mark being produced in at least one of the work steps a) or b) with a non-impact method or a printing method without a fixed printing plate.
2. The method according to claim 1, characterized in that the marking pattern and the relief pattern are produced with the same method in one work step.
3. The method according to claim 1, characterized in that the marking pattern and the relief pattern are produced in separate work steps, wherein the marking pattern can be produced before or after the relief pattern.
4. The method according to at least one of claims 1 to 3, characterized in that the relief pattern is embossed in the substrate with an embossing die, especially in intaglio printing.
5. The method according to at least one of claims 1 to 3, characterized in that the substrate is provided with the relief pattern by the action of a laser beam.
6. The method according to at least one of claims 1 to 5, characterized in that the relief pattern is developed in the form of a grid, preferably a grid having a constant spatial frequency.
7. The method according to at least one of claims 1 to 6, characterized in that the substrate is provided with the marking pattern by the action of a laser beam.
8. The method according to at least one of claims 1 to 6, characterized in that the marking pattern is imprinted on the substrate.
9. The method according to claim 8, characterized in that the marking pattern is applied to the substrate in the ink-jet method or with a digital printing method that works with low pressure.
10. The method according to at least one of claims 1 to 9, characterized in that the marking pattern is developed in the form of a grid, preferably a grid having a constant spatial frequency.
11. The method according to at least one of claims 1 to 10, characterized in that the individualizing mark comprises letters, numerals or a symbol code, such as a barcode or matrix code.
12. The method according to at least one of claims 1 to 11, characterized in that the substrate and/ or the surface of the security element includes further security substances that are activated, exposed, covered, partially destroyed or removed in at least one of the work steps a) or b).
13. A security element having an optically variable pattern that includes a marking pattern having a plurality of flat markings and a relief pattern having a plurality of raised relief elements, the marking pattern and the relief pattern being combined in such a way that different pieces of information are visible from different viewing directions, characterized in that

    - the flat markings are disposed at least in part on sides of the relief elements, a relief element and a flat marking disposed on at least one of its sides together forming a pattern element, and in that

    - the marking pattern and/ or the relief pattern is provided with an individualizing mark that is produced with a non-impact method or a printing method without a fixed printing plate.
14. The security element according to claim 13, characterized in that the relief elements of the relief pattern are disposed in the form of a grid, preferably a grid having a constant spatial frequency.
15. The security element according to claim 13 or 14, characterized in that the flat markings of the marking pattern are disposed in the form of a grid, preferably a grid having a constant spatial frequency.
16. The security element according to claim 14 and 15, characterized in that the grids of the relief pattern and of the marking pattern exhibit the same spatial frequency.
17. The security element according to claim 14 and 15, characterized in that the relief pattern and the marking pattern exhibit slightly different spatial frequencies to produce beat or Moiré effects.
18. The security element according to at least one of claims 13 to 17, characterized in that the flat markings exhibit at least one colored area.
19. The security element according to at least one of claims 13 to 18, characterized in that the flat markings exhibit multiple colored areas that are disposed at least in part on different sides of the relief elements.
20. The security element according to at least one of claims 13 to 19, characterized in that the optically variable pattern includes a plurality of pattern elements that depict a multicolored image motif whose visual impression varies when the viewing angle is changed.
21. The security element according to at least one of claims 13 to 20, characterized in that the individualizing mark comprises letters, numerals or a symbol code, such as a barcode or matrix code.
22. The security element according to at least one of claims 13 to 21, characterized in that the relief pattern and the marking pattern are disposed on a single- or multi-layered substrate.
23. The security element according to at least one of claims 13 to 22, characterized in that the relief pattern and the marking pattern are disposed on a substrate that is single- or multi-layer coated, printed, pasted, clad or laminated.
24. The security element according to at least one of claims 13 to 23, characterized in that the substrate and/ or the surface of the security element exhibits further, especially machine-readable security features.
25. The security element according to at least one of claims 13 to 24, characterized in that the marking pattern and the relief pattern are combined with one or more further layers that depict a pattern or image that is visually perceptible when viewed vertically.
26. The security element according to at least one of claims 13 to 25, characterized in that the relief elements are developed to be tactilely perceptible.
27. The security element according to at least one of claims 13 to 26, characterized in that the relief pattern includes a plurality of non-line-shaped relief elements.
28. The security element according to at least one of claims 13 to 27, characterized in that at least a portion of the non-line-shaped relief elements exhibits substantially the shape of a tetrahedron, a spherical segment, a pyramidal frustum, a conical frustum, a cylindrical segment, a torus segment, an oval, a teardrop or a pyramid.
29. The security element according to at least one of claims 13 to 28, characterized in that the relief pattern is broken down into sub-regions in which different partial relief patterns are disposed.
30. The security element according to claim 29, characterized in that the partial relief patterns each form a grid of the same line screen and, in at least two adjoining sub-regions, the grids of the partial relief patterns are disposed offset by a fraction of the line screen, especially by about one-third of the line screen.
31. A data carrier, especially a value document, such as a banknote, identification card or the like, having a security element according to one of claims 1 to 30.

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