EP2284805B1 - Data carrier with an optically variable structure - Google Patents

Abstract

Security element with an optically variable structure, comprising an embossed structure and a coating, whereby the embossed structure and the coating are combined such that at least part of the coating is fully visible when viewed perpendicularly but hidden on angled viewing. The embossed structure comprises non-linear embossed elements which are combined with the coating such that, on changing viewing angle, different information is visible. An independent claim is made for a method for producing a security element with optically variable surface structure made up of an embossed structure and a coating.

Description

The invention relates to a data carrier with an optically variable structure that has an embossed structure and a coating that contrasts with the surface of the data carrier, the embossed structure and the coating being combined in such a way that at least parts of the coating are completely visible when viewed perpendicularly, but are covered when viewed at an angle and a first item of information can be seen from at least one predetermined viewing angle, which information is not visible or can only be seen very faintly when viewed perpendicularly.

To protect against imitation, especially with color copiers or other reproduction methods, data carriers such as banknotes, securities, credit or identity cards, passports, certificates and the like, labels, packaging or other elements for product security are equipped with optically variable security elements. Protection against counterfeiting is based on the fact that the optically variable effect, which can be easily and clearly recognized visually, is not reproduced or only insufficiently reproduced by the above-mentioned reproduction devices.

For this purpose, for example, from CA 10 19 012 a bank note is known which is provided with a parallel line print pattern in a partial area of its surface. In order to produce the optically variable effect, a line structure is additionally embossed into the data carrier in the area of this line print pattern, so that flanks are created which are only visible from certain viewing angles. By deliberately arranging the line pattern on flanks of the same orientation, these lines are visible when the flanks provided with the lines are viewed obliquely, but the line pattern is not recognizable when the rear flanks are viewed obliquely. If phase jumps are provided in the line grid or in the embossed grid in partial areas of the embossed surface, information can be displayed, which are either only recognizable from the first oblique viewing angle or only from the second viewing angle.

With such an optically variable security element, the tilting effect is very sharp, but only occurs in a very narrow viewing angle range. It is therefore precisely this viewing angle range that has to be found for the visual check of the known optically variable elements, so that these optically variable elements are less suitable for a simple visual check.

U.S. 6,176,521 discloses an optically variable structure having an embossed structure in the form of lines or dots and a colored coating. The colored coating shows variations of color sequences, so that different color impressions arise from different viewing angles. By arranging the color sequences differently, different color fields can be formed, for example to create a motif.

The object of the present invention consists in improving an optically variable security element with regard to its security against forgery and with regard to its visual verifiability.

This object is solved by the features of the independent claims. Advantageous developments are the subject of the subclaims.

According to the invention, the optically variable structure consists of a coating and an embossed structure superimposed on this coating. The embossed structure has non-linear embossed elements that are combined with the coating in such a way that different information becomes visible when the viewing direction changes. The non-linear embossed elements are characterized in particular by at least three flanks, with these flanks having dimensions that enable the shading effect according to the invention. In other words, the flanks must be dimensioned in such a way that an item of information lying behind this flank is at least partially concealed for an observer who is looking at such a flank. Accordingly, the flanks of the non-linear embossing elements form flat or curved surfaces that either merge continuously such as in the case of lateral surfaces of rotationally symmetrical three-dimensional shapes (e.g. spherical segments, truncated cones) or meet at a certain angle, such as in the case of polygonal three-dimensional shapes (e.g. pyramids, tetrahedrons). The non-linear embossed elements can have flanks of flat and/or curved surfaces, in particular the embossed elements can, for example, be in the form of n-sided pyramids, tetrahedrons, truncated pyramids, sections of cylinders, cones, conic sections, paraboloids, polyhedrons, cuboids, prisms, sections of spheres, sections of spheres, segments of spheres, Have hemispheres, barrel bodies or tori. The non-linear embossed elements can also be designed as a so-called divided torus, the torus being divided parallel to the plane in which the large radius of the torus lies. Embossed elements in the form of spherical sections or three- or four-sided pyramids are particularly preferably used. The non-linear embossed elements can preferably be detected tactilely.

The non-linear embossed elements according to the invention also have the advantage that more than two items of information can be easily accommodated in the optically variable element, which are visible from different viewing angles, since the non-linear embossed elements have several flanks on which the information or parts of the Information can be arranged in a targeted and separate manner.

Depending on the shape, height and extent of the non-linear embossed elements, specific visual effects can be created. For example, non-linear embossed elements in the form of a pyramid or truncated cone with steeper flanks provide a more contrasting effect during a tilting movement as e.g. B. non-linear embossed elements in the form of flattened spherical segments with the same embossing height.

An embossing structure with embossing elements that taper to a point at the top usually shows a different appearance of the same information than one with nubs that are flattened at the top and form plateaus, for example. However, pyramidal, spherical segment-shaped or hemispherical embossed elements are preferably used for the invention.

The non-linear embossed elements can be arranged in any way relative to one another in order to create a specific embossed structure. At least part of the embossed structure can consist of non-linear embossed elements arranged in a grid pattern. The non-linear embossed elements form the grid points.

The term "halftone dots" should be understood in the manner known in the printing art. In this case, the grid points have a two-dimensional extent in the substrate plane and are not point-like in the mathematical sense. The analogy used is between the point size (or areal extent) of the grid points and the base area of the non-linear embossing elements in the data carrier plane. In this case, the base area of the non-linear embossed elements in the data carrier plane is actually a projection of the embossed element geometry in the data carrier plane.

The following explanation is based on the "Handbuch der Printmedien", Springer Verlag, page 44 ff. Grid points can accordingly be arranged in a constant periodic grid, in which an arrangement with the same point spacing, the same point size and constant understand dot shape over the entire grid. The possibility of varying the point size creates what is known as an amplitude-modulated periodic screen. One speaks of a non-periodic, frequency-modulated screen of the first order when the dot spacing is variable and the dot size and dot shape remain the same. When applied to the arrangement of the non-linear embossed elements, both possibilities result in advantageous embossed structures.

A structure that has raster dots with variable dot spacing from one another, variable dot size and constant dot shape is referred to as a second-order non-periodic raster. It has been shown that an embossed structure suitable for the invention can also be produced analogously.

Finally, a raster is also conceivable in which all three parameters may be varied and which is called a third-order non-periodic raster. An analogous design and arrangement of the non-linear embossed structures is also conceivable.

All of these types of grids can be used within the meaning of the invention.

The coating of the optically variable structure can be a metal layer, a metal effect layer or an optically variable layer, which is present over the entire surface or in a structured manner on the object to be protected. Alternatively, the coating can also be any desired, preferably printed, geometric pattern. In this way, the coating can be formed from basic pattern elements of different colors, such as lines, triangles, etc. These pattern primitives can be randomized but the dimensions are selected in such a way that the viewer perceives the coating as a homogeneous colored surface.

However, the basic pattern elements can also have at least one colored area, geometric patterns, alphanumeric characters or any image motifs. The different colored areas and/or information of the basic pattern element are preferably arranged on different flanks of the non-linear embossed element, so that the individual colored areas and/or information become visible from different viewing angles.

Alternatively, the basic pattern elements can also be part of any printed image, such as a guilloche pattern or an image motif. For example, in the case of a multicolored guilloche pattern, the pattern primitives may form crossing points of the guilloche lines. The basic pattern element here consists of intersecting, differently colored line sections, the length of which is ultimately determined by the non-linear embossed element arranged in this area.

In the simplest case, however, the basic pattern elements form the raster points of a preferably printed raster.

According to a first embodiment of the optically variable structure, embossed structures and coating are therefore in the form of a grid. The raster elements of the coating are formed by basic pattern elements, each of which has three individual elements in the colors red, green and blue. The individual elements have the shape of triangles or circle segments.

The grid elements of the embossed structure are in the form of three-sided pyramids, which form the non-linear embossed elements. A basic pattern element is assigned to each pyramid, the differently colored individual elements of the basic pattern element being arranged on different flanks of the pyramid and the individual color components of the basic pattern element being arranged on the flanks of the same orientation. The individual elements of the basic pattern element are of the same size and all basic pattern elements of the coating have the same structure, so that the coating appears almost white when the optically variable structure is viewed perpendicularly.

When this optically variable structure is rotated and/or tilted, the proportions of the basic pattern elements that are arranged on the flanks of the pyramids facing away from the viewer are covered. Since these parts no longer contribute to the color impression of the coating, the observer perceives a color that differs from white. In the ideal case, the observer only looks at the flanks of a color, so that the perceived color impression changes from red to blue or green. Since the transitions are rather fluid depending on the viewing angle, the viewer perceives a rainbow effect. This interplay of colors can be easily recognized by the observer without any additional aids and therefore forms an authenticity feature that can be checked easily. At the same time, such a security element can only be imitated with great effort due to the embossed structures used and the necessary registration between the coating and the embossed structure. It therefore offers a high level of protection against counterfeiting.

According to the invention, special optical effects can be achieved by varying the shape of the non-linear embossed elements, the design of the coating, variations in the arrangement of the non-linear embossed elements and/or the coating and the choice of color for the coating.

In the exemplary embodiment described above, additional information can be generated, for example, by varying the coating, e.g. by omitting individual raster elements or by varying the shape of the raster elements. Alternatively, the coating grid remains the same and the grid of the embossed structure is varied. In certain areas, for example, the non-linear embossed elements can be offset relative to the surroundings. Another possibility is to continuously vary the distances between the non-linear embossed elements, i.e. the grid width of the embossed structure, so that a beating occurs with respect to the coating grid. Likewise, individual non-linear embossed elements may be missing or the shape of the non-linear embossed elements may vary.

The combination of a basic pattern element and a non-linear embossing element is referred to below as a "structural element". In the example described above, the combination of a pyramid and a three-colored basic pattern element thus forms the structural element.

According to a further embodiment, the basic pattern element of the structural element can have, for example, only one colored area which is arranged on one of the flanks of the non-linear embossed element. The remaining flanks of the non-linear embossed element show the color of the embossed background, for example the white color of a security. In this case, when the security element is tilted and/or rotated, the viewer perceives an interplay between different brightness levels of the color used. From certain viewing angles the viewer may only perceive the color impression caused by the unprinted paper.

However, structural elements of this type according to the invention can also be designed in an arbitrarily complex and complex manner, as a result of which protection against counterfeiting is increased. The structural elements can be designed and arranged in such a way that no information can be seen in reflected light and the information only emerges from certain viewing angles. The coating can be monochromatic, so that all recognizable information has the same color. However, a mixed color can also be seen when viewed perpendicularly. On the other hand, if you look at it from an angle, you can see different information in different colors.

According to a further preferred embodiment, the structure elements can also be designed in such a way that when the optically variable structure is viewed perpendicularly, a multi-colored image motif can be seen, the visual impression of which, however, varies when the viewing angle changes. This variation ranges from a pure color change to a change in the displayed image information.

In a special embodiment, the structural elements correspond to the pixels of a multicolored image motif, to which specific color components of a primary color system are assigned. The color components assigned to the respective pixel form the basic pattern element, which is combined with a suitable non-linear embossed element. The total area assigned to the basic pattern element is preferably subdivided into areas that are covered with the respective colors of the primary color system. The color impression of the basic pattern element results from the size of the areas covered with the respective colors. These areas can be directly adjacent to each other or also overlapping be. Also, the solids do not have to fill the entire area of the pattern primitive. In this case, the color impression of the basic pattern element is also determined by the color of the background.

If, for example, the primary color system cyan, magenta and yellow is used, three color areas are provided in the total area provided for the basic pattern element, which are arranged in such a way that one color area comes to lie on a flank of the non-linear embossing element used. When viewed from an angle or when rotating such an optically variable structure, individual color components of the image information are covered by the non-linear embossed elements, so that the image information appears in a mixed color of the color areas of the basic pattern elements lying in the viewing direction.

If the non-linear embossed element is designed as a segment of a sphere, for example, then the three colored areas of cyan, magenta and yellow, which are preferably of different sizes, lie on the round lateral surface of the embossed element. In this case, the structural element consists of an embossed element in the form of a segment of a sphere, on the lateral surface of which different colored areas of cyan, magenta and yellow are arranged so that when the structural element is rotated about its axis of symmetry, the different colors become visible one after the other. In order to be able to produce an optically variable structure from such structural elements, which shows colored image information when viewed perpendicularly, the size of the colored areas must vary from structural element to structural element.

Primary colors do not necessarily have to be used for the colored areas; instead, any desired color system depending on the desired effect can be used.

It should be expressly pointed out here that interesting optically variable structures within the meaning of the invention can also be produced with less ordered configurations in which the repeat of the basic pattern elements and the repetition frequency of the embossed structure are not the same or there is no repeat at all. For example, the coating can have differently colored geometric structures as a basic pattern element, which, however, are arranged in an unordered, random manner.

In an advantageous development of the invention, the dimensions of the non-linear embossed elements are designed in such a way that they produce a tactile structure that is easily perceptible to humans. The tactilely perceptible, optically variable structure offers additional protection against imitation through color photocopying or scanning of the data carrier.

The optically variable structure can have additional information that is created by varying the coating and/or the embossed structure. For example, the additional information can be created by varying the shape, size or height of the non-linear embossed elements. A variation of the arrangement of the non-linear embossed elements, such as an offset in some areas or a change in the screen width in some areas or the omission of one or more non-linear embossed elements, is also conceivable. If the coating is varied in the area of an item of information, this can be caused, for example, by a variation in the shape or the color of the coating. A variation of the arrangement of the coating is of course also possible here, such as an offset, a change in the screen width, mirroring or the omission of one or more basic pattern elements.

The embossed structure can also be subdivided into partial areas in which different partial embossed structures are arranged. The partial embossed structures are preferably arranged offset in at least two partial areas bordering one another by a fraction, in particular a third of the screen width. Parts of the partial embossed structures can also have an unembossed edge contour for better recognition.

In connection with this matrix-like arrangement of the partial embossed structures and the generation of additional information in the area of the embossed structures or the coating, reference is expressly made here to WO 97/17211 as well as the WO 02/20280 A1 referenced.

The optically variable structure according to the invention forms a security element that is difficult to imitate and can be arranged directly on any data carrier. However, the optically variable structure can also be part of a security element which, in addition to the optically variable structure, has further security features.

The security element can have, for example, in the area of the optically variable structure, a further colored layer which is preferably translucent and which is arranged congruently with the raised areas of the embossed structure. A wide variety of embodiments are also possible here. For example, some are already in the WO 2004/022355 A2 described, to which reference is also expressly made in this context.

According to a further embodiment, the security element can have further layers or authenticity features, such as a metallic layer, an additional translucent, optically variable layer or a film element. Such layers or elements can be overlaid or underlaid on the optically variable structure.

Finally, it is also possible to equip the coating or the printing inks used to produce the basic pattern elements and/or the ink layer arranged congruently with the raised areas of the embossed structure with machine-readable properties, at least partially. Magnetic, electrically conductive, luminescent additives can be used for this.

The optically variable structure according to the invention or the security element according to the invention is preferably applied to data carriers such as security and valuable documents such as banknotes, shares, bonds, certificates, vouchers, credit or identity cards, passports or the like. In this way, the data carriers are equipped with a security element that is easily recognizable even for laypeople to increase protection against counterfeiting. However, the optically variable structure or the security element according to the invention can also be used very advantageously in the field of product protection. In this case, the optically variable structure or the security element can be applied to corresponding labels or packaging or to the goods themselves.

If paper is used as the data carrier material, cotton vellum papers, paper-like materials consisting of plastic foils, paper coated or laminated with plastic foils or multi-layer composite materials are particularly suitable.

Any desired substrate is preferably used first for the production of the security element according to the invention or the optically variable structure provided with the coating and then produces the embossed structure in register with this coating. In principle, however, it is also possible to provide the method steps in reverse order. The coating is preferably printed on or transferred to the substrate using the thermal transfer method. The coating can be produced in any printing process, such as planographic printing, e.g. offset printing, letterpress printing, e.g. letterpress or flexographic printing, screen printing, gravure printing, e.g. intaglio printing or intaglio printing, or in a thermographic process.

Any method can also be used to produce the embossed structure. The embossing structure is preferably produced by means of an embossing tool, which can be an intaglio printing plate, for example. The embossing is created as a blind embossing using an intaglio printing plate that does not carry ink. According to a special embodiment, however, the embossed structure can also be produced in ink-carrying intaglio printing. This production variant is particularly suitable for the embodiments in which a further colored layer is provided congruently with the embossed structure.

To produce the embossing tool, a plate surface is milled with an engraving tool or a laser, for example. Any material such as copper, steel, nickel or the like can be used as the plate surface. The engraving tool used for the milling preferably has a flank angle of approximately 40° and a rounded tip that approximates a segment or sector of a sphere. The embossing tool can be milled as a single panel or already as a multiple panel.

In principle, the sequence of the two process steps can be freely selected. As a rule, the coating is applied first and then embossed. The height of the relief and the shape of the embossing are thus spared from other influences that occur, for example, in a subsequent printing process. The alternative to this, namely embossing first and then applying the coating, offers the advantage of higher color brilliance and a sharper contoured imprint. This effect is due to the fact that the substrate is simultaneously calendered during the embossing process, giving it a smoother, less absorbent surface.

The advantages of the invention are explained on the basis of the following examples and supplementary figures. The individual features described and the exemplary embodiments described below are inventive on their own, but also inventive in combination. The examples represent preferred embodiments, to which, however, the invention is not intended to be limited in any way. The proportions shown in the figures do not correspond to the conditions present in reality and are only used to improve clarity.

Fig. 1

einen erfindungsgemäßen Datenträger,

Fig. 2

einen Schnitt entlang der Linie A-A aus Fig. 1,

Fig. 3

eine erfindungsgemäße Prägestruktur in Aufsicht,

Fig. 4

eine erfindungsgemäße Beschichtung in Aufsicht,

Fig. 5

eine perspektivische Ansicht einer erfindungsgemäßen optisch variablen Struktur, bestehend aus den in den Fig. 3 und 4 dargestellten Elementen,

Fig. 6a,b

ein tetraederförmiges Prägeelement,

Fig. 7a,b

ein vierseitiges pyramidenförmiges Prägeelement,

Fig. 8a,b

ein pyramindenstumpfförmiges Prägeelement,

Fig. 9a,b

ein kegelstumpfförmiges Prägeelement,

Fig. 10a,b

ein Prägeelement in Form eines Zylinderabschnittes,

Fig. 11a,b

ein Prägeelement in Form eines Torus,

Fig. 12a,b

ein ovales Prägeelement,

Fig. 13a,b

ein tropfenförmiges Prägeelement,

Fig. 14

Prägestruktur aus pyramidenförmigen Prägeelementen in Aufsicht,

Fig. 15

erfindungsgemäße Beschichtung in Aufsicht,

Fig. 16

eine perspektivische Ansicht einer erfindungsgemäßen optisch variablen Struktur, bestehend aus den in Fig. 14 und 15 dargestellten Elementen,

Fig. 17

erfindungsgemäße optisch variable Struktur in Aufsicht,

Fig. 18

Beschichtung gemäß Fig. 4 in Aufsicht mit einem Musterteilbereich,

Fig. 19

eine der Fig. 3 entsprechende Prägestruktur in Aufsicht,

Fig. 20

eine perspektivische Ansicht einer erfindungsgemäßen optisch variablen Struktur, bestehend aus den in den Fig. 18 und 19 dargestellten Elementen,

Fig. 21

Beschichtung gemäß der Fig. 4 in Aufsicht,

Fig. 22

eine Prägestruktur gemäß Fig. 3 mit einer Teilprägestruktur,

Fig. 23

eine perspektivische Ansicht einer erfindungsgemäßen optisch variablen Struktur, bestehend aus den in den Fig. 21 und 22 dargestellten Elementen,

Fig. 24

eine weitere Ausführungsform der optisch variablen Struktur mit einer Teilprägestruktur,

Fig. 25

Beschichtung gemäß Fig. 4 in Aufsicht,

Fig. 26

eine Prägestruktur gemäß Fig. 3 mit einer Teilprägestruktur,

Fig. 27

eine perspektivische Ansicht einer erfindungsgemäßen optisch variablen Struktur, bestehend aus den in den Fig. 25 und 26 dargestellten Elementen,

Fig. 28

eine Ausführungsform der optisch variablen Struktur in Aufsicht,

Fig. 29

eine perspektivische Ansicht eines Ausschnitts aus der in Fig. 28 dargestellten optisch variablen Struktur,

Fig. 30

Ausführungsform der Prägestruktur in Aufsicht,

Fig. 31

Ausführungsform der Prägestruktur in Aufsicht,

Fig. 32a-g

verschiedene Ausführungsformen der erfindungsgemäßen Prägestruktur in Aufsicht,

Fig. 33

erfindungsgemäße Beschichtung in Aufsicht,

Fig. 34

erfindungsgemäße Prägestruktur in Aufsicht,

Fig. 35

perspektivische Ansicht der optisch variablen Struktur, bestehend aus den in den Fig. 33 und 34 dargestellten Elemente,

Fig. 36

erfindungsgemäßes Strukturelement in Aufsicht und in perspektivischer Ansicht,

Fig. 37

erfindungsgemäßes Strukturelement in Aufsicht und in perspektivischer Ansicht,

Fig. 38

erfindungsgemäßes Strukturelement in Aufsicht und in perspektivischer Ansicht,

Fig. 39

erfindungsgemäßes Strukturelement in Aufsicht und in perspektivischer Ansicht,

Fig. 40

erfindungsgemäßes Strukturelement in Aufsicht und in perspektivischer Ansicht,

Fig. 41

eine optisch variable Struktur in Form eines farbigen Bildmotivs in Aufsicht, das jeweils für die Betrachtungsrichtungen A, B und C eine einfarbige Darstellung zeigt,

Fig. 42

Strukturelement in Aufsicht, wie es für die Herstellung des farbigen Bildes gemäß Fig. 41 verwendet wird,

Fig. 43

Strukturelemente der optisch variablen Struktur, gemäß Fig. 41 in Aufsicht,

Fig. 44

erfindungsgemäße Prägestruktur in Aufsicht,

Fig. 45

erfindungsgemäße Beschichtung,

Fig. 46

erfindungsgemäße optisch variable Struktur und Verwendung der Beschichtung gemäß Fig. 45,

Fig. 47

ein erfindungsgemäßer Datenträger im Querschnitt vor der Verprägung,

Fig. 48

ein erfindungsgemäßer Datenträger im Querschnitt nach der Verprägung,

Fig. 49

ein erfindungsgemäßer Datenträger im Querschnitt vor der Verprägung,

Fig. 50

erfindungsgemäßer Datenträger nach der farbführend ausgeführten Verprägung,

Fig. 51

Aufbringen der Beschichtung auf eine Prägestruktur mit berührungslosen Verfahren,

Fig. 52

gemäß Fig. 51 hergestellte, optisch variable Struktur in Aufsicht,

Fig. 53

perspektivische Darstellung der optisch variablen Struktur gemäß Fig. 52,

Fig. 54

Verfahren zum nachträglichen Bedrucken der Prägestruktur,

Fig. 55

Ausschnitt A aus Fig. 54 in Vergrößerung,

Fig. 56

alternatives Verfahren zum Bedrucken der Prägestruktur,

Fig. 57

alternatives Verfahren zum Bedrucken der Prägestruktur.

In detail show schematically:

1

a data carrier according to the invention,

2

cut along line AA 1 ,

3

a top view of an embossing structure according to the invention,

4

a coating according to the invention in a top view,

figure 5

a perspective view of an optically variable structure according to the invention, consisting of in the Figures 3 and 4 elements shown,

Fig. 6a,b

a tetrahedron-shaped embossing element,

Fig. 7a,b

a four-sided pyramid-shaped embossing element,

8a,b

a truncated pyramid shaped embossing element,

9a,b

a frustoconical embossing element,

10a,b

an embossing element in the form of a cylinder section,

11a,b

an embossing element in the form of a torus,

12a,b

an oval embossing element,

13a,b

a drop-shaped embossing element,

14

Embossed structure made of pyramid-shaped embossed elements in top view,

15

coating according to the invention in top view,

16

a perspective view of an optically variable structure according to the invention, consisting of in Figures 14 and 15 elements shown,

17

optically variable structure according to the invention in top view,

18

Coating according to 4 in supervision with a sample area,

19

one of the 3 Corresponding embossed structure in top view,

20

a perspective view of an optically variable structure according to the invention, consisting of in the 18 and 19 elements shown,

21

Coating according to 4 in supervision,

22

an embossing structure according to 3 with a partial embossing structure,

23

a perspective view of an optically variable structure according to the invention, consisting of in the 21 and 22 elements shown,

24

a further embodiment of the optically variable structure with a partial embossing structure,

25

Coating according to 4 in supervision,

26

an embossing structure according to 3 with a partial embossing structure,

27

a perspective view of an optically variable structure according to the invention, consisting of in the 25 and 26 elements shown,

28

an embodiment of the optically variable structure in top view,

29

a perspective view of a detail from the in 28 illustrated optically variable structure,

30

Embodiment of the embossed structure in top view,

31

Embodiment of the embossed structure in top view,

32a-g

various embodiments of the embossing structure according to the invention in plan view,

Figure 33

coating according to the invention in top view,

34

embossing structure according to the invention in plan,

Figure 35

perspective view of the optically variable structure, consisting of in the 33 and 34 elements shown,

Figure 36

structural element according to the invention in top view and in perspective view,

37

structural element according to the invention in top view and in perspective view,

38

structural element according to the invention in top view and in perspective view,

Figure 39

structural element according to the invention in top view and in perspective view,

figure 40

structural element according to the invention in top view and in perspective view,

Figure 41

an optically variable structure in the form of a colored image motif seen from above, which shows a monochrome representation for the viewing directions A, B and C,

Figure 42

Structural element in top view, as required for the production of the colored image Figure 41 is used,

Figure 43

Structural elements of the optically variable structure, according to Figure 41 in supervision,

Figure 44

embossing structure according to the invention in plan,

Figure 45

coating according to the invention,

Figure 46

optically variable structure according to the invention and use of the coating Figure 45 ,

Figure 47

a data carrier according to the invention in cross section before embossing,

Figure 48

a data carrier according to the invention in cross section after embossing,

Figure 49

a data carrier according to the invention in cross section before embossing,

figure 50

data carrier according to the invention after the color-leading embossing,

Figure 51

Application of the coating to an embossing structure using non-contact methods,

Figure 52

according to Figure 51 manufactured, optically variable structure in top view,

Figure 53

perspective view of the optically variable structure according to Figure 52 ,

Figure 54

Process for subsequent printing of the embossed structure,

Figure 55

Section A off Figure 54 in enlargement,

Figure 56

alternative method for printing the embossed structure,

Figure 57

alternative method for printing the embossed structure.

the 1 shows a data carrier 1 according to the invention in the form of a bank note with an optically variable structure 3, which is placed in the printed image area 2 of the data carrier 1 and in the non-printed area. According to the invention, the optically variable structure 3 is used as a so-called human feature, ie as a feature that can be checked by humans without tools, in addition to other features, if any, for determining the authenticity of the data carrier used. The provision of such features is particularly useful for banknotes, but also for other monetary documents such as stocks, checks and the like. Labels, passports or cards can also be used as data carriers within the meaning of the invention. B. to identify people or goods or to carry out transactions or services.

The optically variable structure 3 can have a different construction, combined with the resulting different effects from different viewing directions. According to a preferred embodiment, the optically variable structure 3 consists of a single or multicolored coating contrasting with the surface of the data carrier, such as a pattern, image or alphanumeric information, which is produced by printing or in some other way, such as by means of a transfer process. The effects according to the invention that can be used for checking authenticity are produced by the embossed structure interacting with the coating, depending on the design of the coating and embossed structure and their association with one another.

All optically variable structures according to the invention have in common that they and the resulting effects cannot be imitated using the reproduction techniques known today, in particular copiers, since the copiers can only reproduce the optically variable structure from one viewing direction, so that the optically variable effect is lost.

Examples of various preferred embodiments of the invention are explained below with reference to the figures. The representations in the figures are highly schematic for better understanding and do not reflect the real situation.

For the sake of better comprehension, the embodiments described in the following examples have been reduced to the essential core information. In practical implementation, much more complex patterns or images in single or multi-color printing can be used as a coating. The same applies to the embossed structures. The information presented in the following examples can also be replaced by any amount of complex image or text information. The production of the coating, e.g. as an overprint, usually uses the possibilities of printing technology. Typical diameters of pattern elements from approx. 10 µm are used. The non-linear embossed elements that form the embossed structure generally have an embossing height in the range from 20 to 250 μm and preferably a diameter in the range from 40 to 1000 μm.

The various exemplary embodiments are also not limited to use in the form described, but can also be combined with one another to increase the effects, provided that they fall within the claimed scope, as set out in Example 4.

Furthermore, in the following examples, only the configuration and mutual assignment of the embossed structure and the coating are shown in order to be able to clearly show the optical effects of the optically variable structure according to the invention.

Example 1 (Fig. 2 to 13)

2 shows a schematic sectional view along the line AA (s. 1 ) and in connection with the Figures 3, 4 and 5 an optically variable structure, in which the embossed structure 4 is formed by regularly arranged, uniform, non-linear embossed elements 5, ie is designed as a periodic grid. The non-linear embossed elements 5 are provided with a coating 7 which is in the form of a multicolored pattern whose individual colored areas lie on the flanks of the non-linear embossed elements.

The formation of the non-linear embossed elements 5 as elevations, which are preferably produced by embossing the data carrier, can be clearly seen in the sectional view on the upper side of the data carrier. If the data carrier is mechanically deformed with an embossing tool, the underside of the data carrier material shows the negative deformation. The deformation is shown only schematically here. The back of the data carrier will generally not have such a pronounced and preformed embossing. In the following, only the upper or front side of the data carrier, which is essential for understanding the invention, is considered. The deformation of the bottom or back is not essential to the invention, but merely a side effect of special embossing techniques, such as intaglio printing. However, it can serve as a further authenticity feature.

the Figures 3 and 4 show a section of the individual components of the optically variable structure 3 in a top view. A dashed square grid 6 has been drawn in both figures in order to make orientation easier for the viewer. The pattern repeat of the coating 7 and the repetition frequency of the embossed structure 4 coincide in this example with a side length X of the square grid 6. As shown in FIG 3 As can be seen, the non-linear embossed elements 5 in the example shown have the shape of spherical sections.

In 4 the coating 7 is shown as a pattern of repeating circular areas 8 and squares 9, all circular areas 8 having a first color, e.g. B. cyan, and all squares 9 a second color, z. e.g. magenta. A circular area 8 and a square 9 each are assigned to a spherical section, ie a non-linear embossed element 5, and form the basic pattern elements according to the invention. A cyan-colored circular area 8 and a magenta-colored square colored area 9 come to rest on each non-linear embossed element 5 . With regard to the non-linear embossed element 5, the circular area 8 and the square 9 lie diagonally opposite one another.

the figure 5 shows a perspective view of the interaction in the Figures 3 and 4 components of the optically variable structure 3 shown. The non-linear embossed element 5 arranged within a square according to FIG 3 and the associated coating 7 according to FIG 4 in this case form a structural element 10. For reasons of clarity, only a horizontal row of structural elements 10 has been shown.

From the in the figure 5 only the magenta-colored squares 9 can be seen in the selected viewing direction, which thus characterize the color impression of the optically variable structure 3 from this viewing direction. By rotating and/or tilting the data carrier 1 or the optically variable structure 3, mixed colors between cyan and magenta with different mixing ratios become visible to the viewer, as well as pure magenta, the latter example from one of the position of the viewer according to figure 5 opposite position. The viewer thus perceives a color change game. When viewed perpendicularly, the optically variable structure 3 appears uniformly largely homogeneous in the mixed color of cyan and magenta.

The principle described above can also be used for more complicated image information. In this case, two or more images are broken down into individual pixels, which are arranged in such a way that the pixels belonging to an image come to lie on the flanks of the same orientation. When viewed perpendicularly, depending on the design, only a uniformly colored area or an overall piece of information can be seen. When viewed from an angle, the individual images become visible.

As an alternative, the embossed structure 4 can have embossed elements of any other geometric shape, with a special characteristic of the effect being achieved in each case. For example, embossed elements in the form of a pyramid or truncated cone with steeper flanks provide a higher-contrast effect during a tilting movement than e.g. B. Embossing elements in the form of flattened spherical sections with the same embossing height.

A selection of possible geometries of the non-linear embossed elements show the 6 (a,b) to 13(a,b). the Figures 6a to 13a show a perspective view and the Figures 6b to 13b a plan view of various non-linear embossing elements according to the invention. Without limiting the invention, embossing elements in the form of a tetrahedron ( 6 ), a four-sided pyramid ( 7 ), a truncated pyramid ( 8 ), a truncated cone ( 9 ), a spherical segment ( 10 ), of a torus ( 11 ), of an oval ( 12 ) and a drop ( 13 ) shown.

For security paper, such as cotton vellum paper, non-linear embossing elements in the form of spherical sections with a diameter in the range from 40 to 1000 μm, in particular from 100 to 600 μm, particularly preferably from 470 to 530 μm, have proven to be particularly advantageous. The embossing height is in the range from 20 to 250 μm, in particular in the range from 50 to 120 μm.

The same applies to oval embossing elements in terms of width and embossing height, while lengths of up to 2 cm have been successfully used.

Depending on the substrate material, such as thin paper or strong cardboard, plastic and plastic composite materials, such as paper laminated or coated with plastic, or multi-layer composite materials, certain embossing element shapes and dimensions can be particularly advantageous. The advantageous ranges of values can be far removed from the values determined for security paper.

The non-linear embossed elements are preferably produced by mechanically deforming the data carrier material. For this purpose, an embossing tool according to the invention is used, which is produced with an engraving tool according to the invention. So far, an engraving graver has proven to be particularly suitable in which the tip has been adapted to the special requirements by flattening the tip. This adapted engraving tool preferably has a flank angle of approximately 40°.

The embossing element geometries that can be produced depend on the engraving tool used. For example, if you choose laser engraving as the method for manufacturing the embossing tool instead of an engraving tool embossing element geometries can also be produced with side faces perpendicular to the data carrier plane. For example, cylindrical embossing elements can be created using laser engraving.

Example 2 (Fig. 14,15 and 16)

14 shows another embodiment of the embossed structure 4 according to the invention in a top view, in which the non-linear embossed elements 11 consist of four-sided pyramids. 15 shows the associated coating 7 according to the invention in a top view. It consists of regularly arranged rectangles 12, 13 of different colors. Two differently colored rectangles 12, 13 each form a basic pattern element and belong to a structural element 10 and are arranged in such a way that they are arranged on opposite flanks of the pyramid-shaped embossed elements 11. 16 shows the perspective view of a row of structural elements 10, in each of which the rectangle 12 can be seen.

When viewed perpendicularly, depending on the dimensions of the rectangular areas, the viewer again perceives a uniform, two-dimensional color impression or the rectangular areas themselves. When the data carrier is turned and/or tilted, there is another play of colors.

Example 3 (Fig. 17)

A further variant of the principle according to the invention explained in Example 2 is 17 shown. The optically variable structure 3 has four different images, each of which can be seen from the viewing directions marked with the arrows 1, 2, 3, 4. As in Example 2, the associated embossed structure consists of four-sided pyramids 11. The inventive Coating 7 consists of basic pattern elements with a basically identical structure.

A basic pattern element is composed of four triangles, with an image portion of one of the four images being arranged in each of the triangles. The triangle labeled "1" corresponds to the image seen in gaze 1, the triangle "2" to the image seen in gaze 2, and so on.

If all parts of the image are displayed in the same color, no image information is recognizable when viewed perpendicularly. In the case of a colored design, image information can be recognizable under certain circumstances, but this is different from the images recognizable from the different viewing directions.

Example 4 (Fig. 18,19 and 20)

The special design of the coating and/or the embossing structure can additionally introduce information into the optically variable structure 3 which is not or only very faintly visible in a viewing direction perpendicular to the data carrier plane, but which is easily accessible to an observer when viewed at an angle. This information cannot be reproduced with conventional reproduction techniques and thus increases the counterfeit security of a data carrier equipped in this way.

Example 4 describes the inventive introduction of such information 14 in the optically variable structure 3 by varying the coating 7.

The starting point is the coating 7 according to Example 1, with the arrangement of the circles 8 and rectangles 9 being changed for individual structural elements 10 . In 18 this information area is identified by the solid border 14. Here the circles 8 and the rectangles 9 have been interchanged.

the 19 shows again the periodic embossed structure 4 with embossed elements 5 in the form of spherical sections.

In the 20 is a perspective view of the in the 18 and 19 Coating 7 and embossed structure 5 shown. For reasons of clarity, only the middle row of structural elements 10 is shown. In the area on the right, the observer sees cyan-colored circular areas 8 from an oblique viewing angle, and he perceives the magenta-colored squares 9 in the area on the left.

Any number of structural elements modified in this way can be displayed in any desired form by means of a corresponding configuration and arrangement. For example, letters, company logos, control numbers or decorative elements can be incorporated as information. The coating in the area of individual structural elements can also be missing completely or be replaced by any pattern or information that contrasts with the surroundings.

Example 5 (Fig. 21, 22 and 23)

This example shows the introduction of information by varying the embossed structure.

In the 21 the coating 7 from example 1 can be seen.

22 shows an embossed structure 4, in top view, which consists of different non-linear embossed elements 5, 15. The largest part of the embossed structure 4 consists of embossed elements 5 in the form of spherical sections, as already shown in Example 1. In the area of the information 16, which is identified by the solid border, the embossed elements 15 are in the form of spherical segments.

In the perspective view of 23 it can be seen that in area 16 a substantial part of the coating (here the magenta-colored square 9 of the coating) comes to lie in the valleys lying between the elevations. Since the colored areas 9 in the valleys are shaded much more strongly by the surrounding embossed elements from certain viewing angles than the colored areas 9 on the flanks of the embossed elements 5 in the form of spherical sections, information can be displayed in this way that emerges clearly under certain viewing conditions.

Example 6 (Fig. 24)

the 24 shows a further alternative for generating information 16 by varying the embossing element geometries used. In this case, spherical sections 5, 17 of different heights are used as embossing elements. In this example, the coating 7 corresponds to that in 21 illustrated. The embossing structure is also analogous to that in 22 shown constructed. Only the in 22 spherical segments shown in the area of information 16 are replaced by spherical segments whose height is smaller than that of the surrounding spherical segments 5.

24 shows a corresponding row of structural elements 10. Due to the changed flank angle and the lower height of the embossed elements 17, both the rectangles 9 and parts of the circular areas 8 can be seen in this area. From the perspective of 24 a mixed color between cyan (circular area 8) and magenta (square 9) can be seen in the area of the information 16, while only the magenta-colored squares 9 can be seen in the area of the embossed elements 5. This in turn can be used to display information.

Example 7 (Fig. 25, 26, 27)

A further possibility of forming information 16 by varying the embossed structure 4 is shown in 26 shown. Oval embossed elements 18 are used here. The length L of these oval embossed elements 18 is twice that of the embossed elements 5 arranged outside of the area 16. Accordingly, the structural elements 19 in the information area 16 also have twice the length L in this embodiment, even if the periodicity of the coating 7 over the entire optically variable structure remains the same. In the case of security paper, the length L can be up to 2 cm.

In the area of product security and in the packaging area, the substrates used there, e.g. B. plastic films, cardboard or paper with properties that differ greatly from security paper, completely different embossing element geometries prove to be advantageous, in particular significantly longer oval embossing elements are conceivable. In the packaging sector, however, patterns with a higher number of colors are also widely used, which are produced, for example, in 8-color printing.

As already explained, the embossed structure 4 of the 25 Coating 7 shown superimposed. 27 shows the middle row of the structural elements 10, 19 produced by the superimposition in a perspective view. The structural elements 19 forming the information area 16 consist of oval embossed elements on which two magenta-colored squares 9 and two cyan-colored circles 8 (not shown in the figure) are arranged. Due to the special shape of the embossed elements 18, the orientation of the squares 9 changes with respect to the viewing direction. The viewer perceives this change as a color contrast to the surroundings and the information 16 is thus recognizable to him.

Example 8 (Fig. 28 and 29)

In this example, information is generated by offsetting the non-linear embossed elements.

The coating 7 is identical to the coating explained in Example 1 and consists of basic pattern elements, each containing a colored square 9 and a colored circle 8 . The embossed structure consists of embossed elements 5 in the form of spherical sections.

28 shows schematically both the coating formed from the squares 9 and circles 8 as well as the embossed elements 5 in plan view. In order to clarify the offset of the embossing elements, the basic pattern elements are shown in a square grid 6 with dashed lines. This grid 6 corresponds to the repeat of the basic pattern elements. In column A of this square grid 6, the embossed elements 5 have the same repeat as the basic pattern elements and are arranged in such a way that both all circles 8 and all squares come to rest on the flanks of the embossed elements 5. In the column B of the square grid 6 are the embossed elements 5 by the distance a shifted to the right. In this way, only the squares 9 lie on the flanks of the embossed elements 5. In the columns C and D of the square grid 6, the embossed elements 5 are additionally offset downwards by the distance b.

29 shows a perspective view of a number of structural elements according to FIG 28 from the viewing direction BE. Column labels A, B, C, D are also shown for clarity. The observer perceives the squares 9 in the area of the structural elements belonging to column A. In the area of column B, the circles 8 that are not arranged on a flank of the embossed element 5 also contribute to the color impression of the structural element. In the area of columns C and D, the square 9 is located on the side of the embossed element 5 facing away from the viewer, so that the color impression is primarily determined by the circles 8 .

Example 9 (Fig. 30)

the 30 shows other ways of offsetting the non-linear embossed elements against each other. For example, the distance c corresponds to the distance between two embossing element centers. The embossed elements can be offset by fractions or multiples of c or d in the x and/or y direction. In the example above, there is an offset of 1.5 c in the x-direction and 0.5 d in the y-direction.

Example 10 (Fig. 31)

Another way of generating information is by rotating non-rotationally symmetrical embossed element shapes, such as e.g. B. an embossing element in the form of a spherical segment given. the 31 shows embossing elements 25, which are rotated by 90 ° and embossed elements 26, which are rotated by 45 ° in the plane of the drawing against each other. Other angular relationships can also be used to advantage.

A further development provides for the rotation of the non-linear embossed elements to be combined with a displacement, ie an offset. This results in a wide range of possible partial embossing structures for introducing information.

Example 11 (Fig. 32a to g)

In 32 special embossed structures 4 are shown in a top view in order to explain the range of possible arrangements, configurations and possible combinations of the non-linear embossed elements. These can be used for the entire embossed structure 4 or only in the area of additional information in the form explained using the examples above.

32a shows the periodic arrangement of spherical sections from example 1. The embossed elements 5 are arranged at a distance from one another. The distance can be very small, for example less than 10 μm. A distance of 2 µm between the embossing elements is particularly advantageous. Since the embossing tool cannot be produced using conventional etching technology for such a small distance, this configuration further increases the forgery security of the optically variable structure.

Arbitrarily larger distances can also be used. Preferred distances are 10 to 300 μm.

Figure 32b shows an embossed element arrangement placed as closely together as possible with a gap.

In the 32c an alternating arrangement of spherical sections with a large and a small diameter of their bases is shown. For example, four small embossed elements 20 can be accommodated on the surface that occupies the base area of a large embossed element 5 .

Figure 32d shows alternating embossed elements 5, 21 with a circular and with a rectangular area as the base area.

Figure 32e 12 shows oval embossed elements 18 alternating with embossed elements 5 in the form of spherical sections. Two embossed elements 5 are provided in the longitudinal extension of an oval embossed element 18 . In principle, the oval embossed element 18 can be viewed as a distorted spherical segment embossed element that has been stretched or compressed in a preferred direction.

32f and g finally shows an embossed structure in which the embossed elements 5 are arranged overlapping one another in certain areas, ie the embossed elements were engraved overlapping or into one another during production of the embossing tool, resulting in an embossed structure in the form of a chain of hills.

It has been shown that information generated via a variation in the embossed structure is hardly recognizable when viewed perpendicularly, so that hidden information can be generated in this way. Changes in the coating, on the other hand, are usually slightly perceptible when viewed perpendicularly.

A further improvement in the effect can be achieved by a suitable combination of the two options for introducing information.

Example 12 (Fig. 33,34, 35)

The coating 7 is preferably designed as a printed pattern and also offers a wide range of possibilities for variation.

the Figure 33 Figure 12 shows a two-tone coating made up of squares 27a, eg, magenta, and 27b, eg, cyan. The square grid 6 drawn in dashed lines indicates the area that is available for a basic pattern element. The squares 27a, 27b each take up about a quarter of this area. The coating 7 is divided into three areas A, B, C, which can be seen from the solid lines 22 . In area A, the squares 27a, 27b are arranged in the vertical direction in alternating colors and adjacent to one another. In the horizontal direction, squares 27a, 27b of one color are spaced from each other. The space 27c is preferably unprinted so that the substrate material is visible. This pattern is hereinafter referred to as "basic pattern".

The pattern portion B is generated by shifting the basic pattern by one square side length in the vertical and horizontal directions. A first piece of information can thus be displayed in the optically variable structure, which is visible from certain viewing directions. By interchanging the rows and columns of the basic pattern, a partial pattern area C is created, with which a second piece of information is represented, which is clearly visible from a different viewing angle range. The boundary lines 22 serve merely for clarity, in order to be able to optically better separate the individual partial pattern areas A, B, C from one another.

In addition, further pattern sub-areas z. B. be generated by a further shift by a fraction of a square side length.

It has been shown that precisely through the integration of free, i. H. not or only transparently printed or coated substrate surface in the pattern a very lively and striking color change is generated, in which the information for a viewer is particularly easy to see.

In combination with a suitable embossed structure, a complex, optically variable structure is available, which shows a viewer different information for a number of different viewing angle ranges. A suitable periodic embossing element arrangement is in 34 shown.

the Figure 35 shows the second row of structure elements 28 from above to illustrate the different visual impression of the different partial pattern areas (A, B and C) from an exemplary viewing direction BE Figure 33 in perspective view.

Examples 13 to 17 (Figs. 36 to 40)

the 36 to 40 show structural elements 29, from which other suitable optically variable structures can be generated, in plan view (a) and exemplarily combined with an embossed element 5 in the form of a spherical segment in a perspective view (b).

Figure 36 shows the structural element 10 according to example 1 in top view (a) and in a perspective view (b).

the 37 12 shows a structural element 29 which has a pattern printed in two colors, for example a cyan circular area 8 and a magenta semicircular area 30 . The semicircular area 30 determined from the perspective of Figure 37b the color impression. When the data carrier is rotated through 180°, the cyan-colored circular area 8 determines the color impression. Changing mixed colors can be seen on the way there.

the 38 12 also shows a magenta-colored semicircular area 30 and a yellow semicircular area 31 partially overlapping this area. A mixed color is produced in the overlapping area 32, resulting in a color effect similar to that of a pattern printed in three colors.

In the Figure 39 a three-colored basic pattern element is shown, which is made up of circular sectors 34, 35, 36, which are each arranged like spokes. In the ideal case, a group of three 34, 35, 36 is placed on a knob 5. When turning and/or tilting, the colored circular sectors 34, 35, 36 appear one after the other.

figure 40 finally shows a printed with a portion of a stripe pattern 37 embossing element 5. This stripe pattern 37 is printed in one color, so that the viewer from the perspective of Figure 40b the color of the stripe 37 perceives. Since the back of the embossing element 5 is unprinted, the observer only perceives the color of the substrate when the viewing angle changes by 180°. This results in an interplay of the brightness of the rotating and / or tilting of the optically variable element hue used for the color stripes. This embodiment also has an appealing, rather subtle effect.

The stripe pattern 37 can also be made up of curved lines and/or have a multicolored design. A pattern containing guilloches is also suitable for the invention.

A further advantageous variation of the coating consists in reducing or enlarging the individual colored areas of the pattern belonging to the basic pattern element, with the pattern repeat preferably not changing in its dimensions. It has been shown that an optically variable element that changes color very conspicuously can be produced in this way.

Example 18 (Figs. 41, 42 and 43)

According to a further embodiment, the coating according to the invention can be a complicated image, which is preferably printed in multicolor printing, instead of a simple geometric pattern.

Figure 41 shows an example of an optically variable structure in which such a colored image 40 is used. When viewed perpendicularly, the image 40 appears in the usual multicolor. On the other hand, when viewed from viewing directions A, B and C, one color predominates in each case. To produce this optically variable effect, the image 40 is broken down into pixels of equal size and the associated color components cyan, magenta and yellow are assigned to each pixel. In the present case, these color components are arranged in circle segments 41, 42, 43, which Figure 42 are indicated by the dashed lines 38. The color of the pixel is determined by the assignment of the

Circle segments 41, 42, 43 set with color. This in Figure 42 However, the pixel shown is only covered with the colors cyan (c), magenta (m) and yellow (y) in the circle segments 41, 42, 43 in the areas 41a, 42a, 43a, so that this pixel when viewed perpendicularly is one of the color mixture corresponding hue. The color areas 41a, 42a, 43a here form the basic pattern element according to the invention. In Figure 42 At the same time, the projection of a non-linear embossed element 5 is shown in order to show how the embossed element is ideally arranged relative to the circle segments 41, 42, 43. This spatial arrangement between the color components cyan, magenta and yellow and embossing element 5 is fixed for the entire image 40, as shown in FIG Figure 43 apparent. The embossed element 5 and the associated color portions 41a, 42a, 43a therefore form a structural element 39 within the meaning of the invention.

In Figure 43 a detail from the image 40 is shown in a top view, greatly enlarged, so that the individual pixels or basic pattern elements and the respective associated color components are visible. The embossed elements 5 are also shown schematically as a projection, so that it can be seen that the non-linear embossed elements and the associated color portions 41a, 42a, 43a of the pixel form the structural elements 39. From this it follows that when viewing the image 40 from the direction A ( Figure 41 ) the cyan components determine the image impression, while from viewing direction B the magenta components predominate and from viewing direction C the yellow components predominate. Rotating and/or tilting the optically variable element results in interesting color changes that cannot be reproduced using other means.

Of course, all other imaginable color systems as well as any colors or paints can be used. Special paints can also be used instead of individual color components or all color components, that produce matt or shiny surfaces. An integration of matt-gloss effects in the print can further enhance the effect of the optically variable structure. Alternatively, the colored areas of the basic pattern elements can also be arranged in an overlapping and/or asymmetrical and/or randomly generated manner.

Example 19 (Fig. 44)

In the exemplary embodiment described here, soft and sharp transitions between the information that is visible from the different viewing angles are produced by the special selection of the geometry of the non-linear embossed elements.

Figure 44 shows a corresponding embossed structure in plan view. It consists of a square field 50 in which four-sided pyramids 51 are arranged as non-linear embossed elements. This field 50 is surrounded by embossed elements in the form of spherical segments 52 . When the optically variable element is rotated and/or tilted, the sharp-edged flanks of the pyramids 51 produce a sharp transition between the individual pieces of information arranged on the flanks. The spherical segments, on the other hand, result in a continuous and therefore smooth transition between the information due to their round shape.

If there is a single-colored image on the pyramid-shaped embossed elements and a multicolored background on the spherical segments, then when the security element is rotated and/or tilted, the single-colored image appears and disappears abruptly against a colored background that varies smoothly from one color to another and, for example, one shows rainbow effect.

Example 20 (Fig. 45, 46)

In this exemplary embodiment, the coating 7 consists of a full-area, single-color background print 53 which has recesses 54 in the form of semicircles. This coating is combined with an embossed structure in the form of spherical sections 55, with the cut surfaces 56 of the spherical sections 55 coinciding with the recesses 54 ( Figure 46 ). In this way it is achieved that the gaps can only be seen from a defined viewing direction and in a narrow angular range.

The recesses can, of course, have any desired shape. The coating can also consist of a metal layer that is transferred to a corresponding substrate in the transfer process.

Example 21 (Fig. 47 and 48)

The optically variable element is preferably produced by printing. For this purpose, the coating is printed onto a substrate, preferably the document material, using any printing method, preferably offset printing, and then this coating is correspondingly embossed with an embossing tool. An intaglio printing plate is preferably used as the embossing tool. This procedure is in the 47 and 48 shown.

the Figure 47 shows a data carrier according to the invention in cross section before the embossing process. In this case, the data carrier substrate 44 is initially provided with a background layer 45, e.g. B. printed all over. The coating 7 is applied over this.

The background layer 45 can also be in the form of information and patterns. Special printing inks can also be used, which further increase the anti-counterfeiting effect of the optically variable element. These can be optically variable printing inks, such as printing inks containing interference layer pigments or liquid crystal pigments, or metallic effect inks, such as gold or silver effect inks.

the Figure 48 shows a sectional view of the data carrier after embossing, which in the example shown was produced as blind embossing using the intaglio printing process. The embossing is placed in such a way that the coating 7 comes to rest on the flanks of the embossed structure.

Alternatively, the background 45 can also be applied over the entire surface or also provided with recesses or a pattern in another method, for example in a transfer method. Metallic pattern elements or coatings can also be applied in the transfer process.

Example 22 (Fig. 49 and 50)

The background layer 45 can also be completely dispensed with, as in Figure 49 shown. On the other hand, the embossing, which is produced, for example, in steel intaglio printing, is executed in color.

the Figure 49 shows the structure before embossing with substrate 44 and coating 7. In FIG figure 50 the situation after embossing is shown. The Indian Figure 49 The structure shown was embossed in a color-leading manner, so that an ink layer 46 is present congruent with the embossing. The extra layer of paint 46 is the top layer, since this embossing was carried out as the last step in the process.

An at least translucent color is preferably used for the color layer 46 . In a modification, the color-carrying intaglio printing can be carried out in such a way that an application of color takes place only on the non-linear embossed elements, but the valleys between the non-linear embossed elements remain free of ink.

In a development, a color with machine-readable additives, such as luminescent substances, can be used for the color layer 46 .

Example 23 (Figs. 51 to 53)

This example describes an alternative for the manufacture of the optically variable element in which the substrate material is first embossed and then the embossed surface is provided with the coating.

the Figure 51 shows a detail from a document material 44 in supervision. The material 44 is provided with an embossed structure which has periodically blind embossed embossed elements in the form of spherical sections 5 . This document material 44 passes through a marking device 47 which has means for contactless marking, such as one or more inkjet print heads. The marking device 47 produces the coating according to the invention on the already existing embossed structure. In this case, the coating consists of basic pattern elements arranged in the form of a grid, most of the basic pattern elements having a circular area 8 and a square 9 . For some pattern primitives, the square 9 is replaced by the information 48 in the form of the letters "A", so that the coating has an additional information 48.

the Figure 52 shows the finished printed substrate section 44 in plan view. In the Figure 53 12 is a perspective view of the middle row of pattern primitives of FIG Figure 52 shown.

In addition to or as an alternative to the inkjet print heads, the marking device 47 can have one or more laser scan heads, which have pattern elements that can be selected individually for each location on the embossed structure, e.g. B. the letter A, inscribe by introducing the energy of the laser beam in the substrate of the data carrier or in a coating.

Registering between the embossed structure and the coating can also be done by means of registration marks or by using a device for image acquisition and processing. For this purpose, for example, embossing element peaks or valleys must be detected by the image acquisition and processing and their position must be made available as input values for the control of the marking device.

the Figures 54 to 57 show alternative possibilities for producing the security element according to the invention, in which first the embossed structure is produced and then the coating is applied to the individual non-linear embossed elements.

According to Figure 54 the already embossed substrate 100 is guided past two inkjet heads 101, 102 via a roller. Due to the curvature of the roll, the embossing structure 103 is pulled apart and fanned out somewhat, so that the inkjet heads 101, 102 can each print an embossed element on the respective flanks. This is shown in section A in Figure 55 shown. Another possibility is in Figure 56 shown. Here the substrate 100, which has already been provided with the embossed structure, is transported in the plane. The inkjet heads 101, 102 are arranged in such a way that they can each print on one of the non-linear embossed elements. After one of the non-linear embossing elements has been printed accordingly, the inkjet heads 101, 102 are Figure 56 arrows shown. As soon as a line of non-linear embossing elements has been printed, the inkjet heads 101, 102 are moved one line further down and the next line of non-linear embossing elements can be printed.

Alternatively, of course, the substrate 100 can also be moved.

Figure 57 shows an arrangement with which a non-linear embossed element can be printed with four different print images. Such an arrangement can also be used in the embodiments described above.

However, since the coating and embossed structure are produced separately from one another, register fluctuations can always occur, which means that the assignments between embossed structure and coating shown in the figures as ideal versions cannot always be maintained. However, since the optically variable effect nevertheless occurs in a clearly visible manner, these embodiments are of course also covered by the invention.

Claims (34)

1. A security element having an optically variable structure (3) which has an embossed structure (4) and a coating (7), wherein the embossed structure (4) and the coating (7) are so combined that at least parts of the coating (7) are completely visible upon perpendicular viewing, but are shadowed upon oblique viewing, wherein the embossed structure (4) has non-line-shaped, raised emboss elements (5), on whose flanks pattern base elements (8, 9) of the coating (7) are arranged at least partially in such a way that different information becomes visible in the optically variable structure (3) upon a change of viewing direction, wherein the optically variable structure (3) has an additional information (14) which results from variation of the coating (7), characterized in that the additional information (14) cannot be recognized or can be recognized only very weakly upon perpendicular viewing, yet can be recognized upon oblique viewing.
2. The security element according to claim 1, characterized in that at least a part of the non-line-shaped emboss elements (5) is arranged in a grid-shaped manner.
3. The security element according to claim 1 or 2, characterized in that at least a part of the non-line-shaped emboss elements (5) is designed to be tactilely detectable.
4. The security element according to any of claims from 1 to 3, characterized in that at least a part of the non-line-shaped emboss elements (5) has essentially the form of a tetrahedron, a spherical section, a truncated pyramid, a truncated cone, a cylindrical section, a torus, an oval, a drop or a pyramid.
5. The security element according to any of claims 1 to 4, characterized in that the coating (7) is in the form of a grid, preferably a printed screen.
6. The security element according to any of claims 1 to 5, characterized in that the coating (7) is a metal layer, a metal effect layer or an optically variable layer.
7. The security element according to any of claims 1 to 6, characterized in that the pattern base element (8, 9) has at least one colored area.
8. The security element according to any of claims 1 to 7, characterized in that the pattern base element (8, 9) has a several colored areas, which are arranged at least partially on different flanks of the non-line-shaped emboss element (5).
9. The security element according to claim 8, characterized in that the pattern base elements (8, 9) have colored areas in the colors of a primary color system.
10. The security element according to any of claims 1 to 9, characterized in that the pattern base element (8, 9) has a geometric pattern and/or alphanumeric information.
11. The security element according to any of claims 1 to 10, characterized in that the coating (7) consists at least partially of pattern base elements (8, 9) arranged at a distance from each other and the embossed structure (4) consists at least partially of non-line-shaped emboss elements (5) arranged at a distance from each other, wherein at least one pattern base element (8, 9) is arranged at least partially on the flanks of a non-line-shaped emboss element (5), so that the pattern base element (8, 9) and the non-line-shaped emboss element (5) form a structure element (10).
12. The security element according to any of claims 1 to 11, characterized in that the optically variable structure (3) has a plurality of structure elements (10) which, upon perpendicular viewing, represent a multicolored image motif whose visual impression varies upon changing the viewing angle.
13. The security element according to any of claims 11 or 12, characterized in that the structure elements (10) correspond to image points of the image motif to which specific color portions of a color system are assigned, and in that the pattern base elements (8, 9) have colored areas in the colors of the color system, wherein the size of the colored areas of the pattern base elements (8, 9) corresponds to the respective color portion of the image points, so that the color impression of the optically variable structure (3) varies upon changing the viewing angle.
14. The security element according to any of claims 1 to 13, characterized in that the additional information (14) also results from variation of the embossed structure (4).
15. The security element according to any of claims 1 to 14, characterized in that the additional information (14) also results from a variation in the shape, size or height of the non-line-shaped emboss elements (5).
16. The security element according to any of claims 1 to 14, characterized in that the additional information (14) also results from variation of the arrangement of the non-line-shaped emboss elements (5), such as offset, change of the screen width, omission of single or multiple non-line-shaped emboss elements.
17. The security element according to any of claims 1 to 16, characterized in that the additional information (14) results from a variation in the shape or color of the coating (7).
18. The security element according to any of claims 1 to 16, characterized in that the additional information (14) results from a variation in the arrangement of the coating (7), such as offset, change in the grid width, mirroring or omission of single or multiple pattern base elements (8, 9).
19. The security element according to any of claims 1 to 18, characterized in that the optically variable structure (3) has a further ink layer (46) which is preferably translucent and which is arranged congruently with the raised regions of the embossed structure (4).
20. The security element according to any of claims 1 to 19, characterized in that the optically variable structure (3) has a metallic background layer (45).
21. The security element according to any of claims 1 to 20, characterized in that the coating (7) and/or the further ink layer (46) has/have machine-readable properties at least regionally.
22. The security element according to any of claims 1 to 21, characterized in that the coating (7) and/or the further ink layer (46) has/have magnetic, electrically conductive or luminescent properties.
23. The security element according to any of claims 1 to 22, characterized in that the optically variable structure (3) is superimposed or underlaid with an additional translucent optically variable layer or a foil element.
24. The security element according to any of claims 1 to 23, characterized in that the embossed structure (4) is subdivided into partial regions in which different partial embossed structures are arranged.
25. The security element according to claim 24, characterized in that the partial embossed structures or partial coatings are offset in at least two adjacent partial regions by a fraction, in particular a third, of the grid spacing.
26. The security element according to any of claims 24 or 25, characterized in that at least the partial embossed structures of a partial region have an unembossed edge contour.
27. A data carrier (1) having a security element according to any of claims 1 to 26.
28. The data carrier according to claim 27, characterized in that the data carrier (1) is a paper of value, in particular a banknote.
29. The employment of a security element according to any of claims 1 to 26 or of a data carrier according to claim 27 or 28 for product authentication.
30. A method for manufacturing a security element having an optically variable structure (3) which has an embossed structure (4) and a coating (7), wherein the embossed structure (4) and the coating (7) are so combined that at least parts of the coating (7) are completely visible upon perpendicular viewing, but are shadowed upon oblique viewing, wherein a substrate (44) is provided with an embossed structure (4) which has non-line-shaped, raised emboss elements (5), and pattern base elements (8, 9) of the coating (7) are arranged at least partially on flanks of the emboss elements (5) in such a way that different information becomes visible in the optically variable structure (3) upon a change of viewing direction, wherein the embossed structure (4) is produced in such a way that an additional information (14) is accommodated in the optically variable structure (3) which results from variation of the coating (7), characterized in that the additional information (14) cannot be recognized or can be recognized only very weakly upon perpendicular viewing, yet can be recognized upon oblique viewing.
31. The method according to claim 30, characterized in that the coating (7) is imprinted on the substrate (44).
32. The method according to claim 31, characterized in that the imprint is generated by planographic printing, such as, for example, by the offset process, by relief printing, such as, for example, by letterpress printing or by the flexographic printing process, by screen printing, by gravure printing, such as, for example, by halftone gravure or by intaglio printing, or by a thermographic process, such as, for example, by the thermal transfer method.
33. The method according to any of claims 30 to 32, characterized in that the embossed structure (4) is produced by means of an embossing tool.
34. The method according to any of claims 30 to 32, characterized in that the embossed structure (4) is produced by intaglio printing.

Images