EP3401117A1 - Security element, and value document comprising such a security element - Google Patents

Abstract

The invention relates to a security element for a security paper, value document or the like, with
a carrier which has a motif area (3) which provides a visually perceptible motif with a first and a second motif part (4, 5), one of the two motif parts (4, 5) serving the other of the two motif parts (4, 5) at least partially surrounds,
wherein the motif area (3) presents a first micro-optical representation arrangement (11) which, as a first motif part, presents at least two different images depending on the viewing angle,
and a second micro-optical representation arrangement (17) which, as the second motif part (5), presents a reflective surface that appears curved in relation to the actual macroscopic spatial form of the second micro-optical representation arrangement (17),
wherein the first micro-optical representation arrangement (11) presents the at least two different images such that a viewer obtains a stereographic representation of an object having absolute depth information and / or an orthoparallactic representation of the object.

Description

The present invention relates to a security element for a security paper, value document or the like, as well as a value document with such a security element.

Items to be protected are often provided with a security element which allows verification of the authenticity of the item and at the same time serves as protection against unauthorized reproduction.

Items to be protected include, for example, security papers, identity and value documents (such as bank notes, chip cards, passports, identification cards, identity cards, shares, attachments, certificates, vouchers, checks, tickets, credit cards, health cards, etc.) as well as product security elements (such as labels, Seal, packaging, etc.).

There are known security elements that a micro-optical representation arrangement in the form of a moiré magnification arrangement, as for example in the WO 2007/076952 A2 is described or in the form of a modulo magnification arrangement, as for example in the WO 2009/000528 A1 is described to produce a three-dimensional image impression that is memorable. At the same time, such a security element is difficult to imitate because the micro-optical structure is difficult to copy or replicate. However, since counterfeiters always work to fake known security elements, there is a need for security elements with increased security against counterfeiting.

Based on this, the object of the present invention is to provide a security element for a security paper, value document or the like which is more difficult to copy or simulate.

According to the invention, the object is achieved by a security element for a security paper, document of value or the like, having a carrier which has a motif area which provides a visually perceptible motif with a first and a second motif part, the motif area being a first microoptical representation arrangement Motive part viewing angle dependent presents at least two different images, and a second micro-optical representation arrangement comprises, which presents a reflective surface as the second part of the subject, which appears curved relative to the actual macroscopic spatial form of the second micro-optical representation arrangement.

In the case of the security element according to the invention, the motif region has the first and second motif part, which comprises different micro-optical representation arrangements, which as a rule make distinctly different demands on their production processes, in particular on origination. This means that a counterfeiter must master both manufacturing processes, which increases the security against counterfeiting.

Furthermore, due to the two micro-optical representation arrangements, the security element according to the invention has a very high optical attractiveness and thus a particularly high recognition value. As a result, the user, if the security elements are, for example, a security element for a banknote, preferably checks the banknote for authenticity on the basis of this attractive security element. As a result, the requirements for a counterfeiter are increased since he is both micro-optical Must mimic or duplicate high-quality representations, which is very expensive to produce a forgery that is not recognized as such by the user.

The two motif parts are preferably arranged (spatially) contiguously, so that the images presented by both micro-optical representational arrangements can be perceived by the user as a single motif.

The contiguous arrangement is understood in particular to mean that the distance between the two motif parts is preferably less than 1 mm and particularly preferably less than 0.2 mm. Furthermore, both subject parts can be directly adjacent to each other.

For the user, therefore, it is preferably not recognizable, at least in a particular viewing or lighting situation, that two different microoptical display arrangements are present. He recognizes only the optically differently represented parts of the subject, but sees this as an aesthetic stylistic device of the representation of the motif. He will therefore perceive the entire motif as such, at least in the particular viewing or lighting situation.

The security element can preferably be designed such that one of the two motif parts at least partially surrounds the other of the two motif parts. In particular, the surrounding motif part can completely surround the other motif part in the manner of a frame.

Furthermore, it is possible that both motif parts overlap at least partially and / or are at least partially interleaved with one another.

A frame or the arrangement of the first and second part of the motif at very short intervals increases the security against counterfeiting, especially when the two micro-optical representations have to be produced with different origination methods and / or can not be coined at the same time. A forger then not only has to master two origination and / or embossing processes, but also has to position the motifs produced in exact registration with each other. In particular, nested subject parts are then extremely difficult to fake.

Any existing different dependency of the visual appearance of the two micro-optical representation arrangements of the present viewing or lighting situation can also be used specifically for further effects. In particular, the security element according to the invention may advantageously be designed such that, depending on the viewing and / or illumination situation, the representation of one of the microoptical representation arrangements dominates, while the representations of the first or second microoptical representation arrangement in a different viewing or illumination situation become one overall motif complete.

In a further advantageous embodiment, which will be described in more detail below, the first micro-optical representation arrangement provides a representation independent of the illumination direction at a constant viewing angle, while the representation of the second micro-optical representation arrangement varies depending on the illumination direction.

The security element may also be designed such that one of the two micro-optical representation arrangements represents a background, in front of which the other of the two micro-optical representation arrangements shows an object, so that overall a three-dimensional overall view can be perceived as a motif.

In the case of the security element according to the invention, the first micro-optical representation arrangement can present the at least two different images as a function of the viewing angle such that the images overlap at least in regions and / or are nested one inside the other.

The first micro-optical representation arrangement can present with particular advantage two different views of the same object as the at least two different images.

Furthermore, it is possible for the at least two different images to be displayed in such a way that a viewer obtains a stereographic representation of an object with absolute depth information. For the viewer, therefore, the object is apparently positioned in front of or behind the carrier, wherein the apparent distance from the carrier and thus the depth information is determined by the formation of the first micro-optical representation arrangement.

In particular, more than two different images of the same object can be presented by means of the first micro-optical representation arrangement such that a parallax results. It can thus be achieved that image components of the first motif part in the foreground move relative to image components of the first motif part in the background when the viewing angle changes. This can even cause you to quasi can look behind an object shown in the foreground of the first part of the subject.

In an advantageous embodiment, the first micro-optical representation arrangement can have a hologram. The hologram can be, for example, an embossed hologram. In particular, it may be a volume hologram. Furthermore, the hologram may conventionally be a directly exposed hologram or even a computer generated stereogram.

In another advantageous embodiment, the first micro-optical representation arrangement can comprise microstructures and microimage elements in order to image the microstructures in an enlarged manner. In particular, the first micro-optical representation arrangement can be designed as a microlens tilt image, as a moiré magnification arrangement or as a modulo magnification arrangement.

The microimage elements can be designed as focusing elements. They can be designed as one-dimensionally focusing elements (for example cylindrical lenses or corresponding hollow micromirrors) or else as two-dimensionally focusing elements (for example spherical or aspherical lenses or corresponding micromill mirrors). Furthermore, it is possible for the microimage elements to be designed as a hole pattern.

The microstructures and / or the microimage elements can be arranged in a one- or two-dimensional grid, wherein the screen ruling is preferably less than 300 μm, in particular less than 100 μm and particularly preferably less than 40 μm.

In the case of the security element according to the invention, the first micro-optical representation arrangement can present a tipping image with at least two different views of the same object by means of the at least two different images. The different views can show the same object in such a way that a stereographic impression of depth results. However, the different views can also have a parallax which differs slightly from the parallax necessary for an absolute depth information, so that, in addition to a three-dimensional impression, a movement of the object shown is also presented to the viewer when the viewing angle is changed. Furthermore, it is possible to represent the at least two different views orthoparallaktisch, as for example in the WO 2007/076952 A2 is described. Strictly speaking, the representations for the viewer's left and right eyes do not permit the assignment of a depth, since the viewing directions under which the observer sees the object with the left and right eye do not intersect.

The first micro-optical representation arrangement can therefore also be designed such that it provides a viewing angle-dependent motion effect, which can be effected with or without absolute depth information relative to the carrier. In particular, orthoparallactic representations are possible.

The second micro-optical representation arrangement is in particular designed so that the arched appearing reflective surface presents a relief-like impression. This impression is particularly such that regardless of the viewing angle always the same relief-like impression is conveyed. The observer has the impression of an arched, reflective surface although the macroscopic spatial shape of the second microoptical representation is usually planar.

Advantageously, the second micro-optical representation arrangement has embossed microscopic structures which are provided with a reflection-enhancing coating.

In particular, the second micro-optical representation arrangement may comprise a plurality of reflective facets with varying orientations. The orientations are preferably selected such that, due to the reflection directions predetermined thereby, the convex surface is imitated or readjusted for a viewer. By "reflective" facets is meant not only facets that have a reflectance of nearly 100%, but also facets that are semitransparent (eg, with a very thin or rasterized metal layer) or even substantially transparent (eg, with a high refractive dielectric coating) are formed. If the facets form the interface between layers with different indices of refraction, the trailing domed surface can also be seen through refraction. For example, the facets can be embossed in a high-index embossing lacquer and embedded in a low-breaking protective lacquer. Furthermore, it is preferred that the facets have a maximum size that is below the resolution of a viewer (without optical aids). Thus, the lateral dimensions are preferably less than 300 μm, in particular less than 100 μm and particularly preferably less than 20 μm. The facet height is preferably less than 20 μm, in particular less than 10 μm and particularly preferably not greater than 5 μm.

Furthermore, it is possible for the second microoptical display arrangement to have a reflective grating period Fresnel structure. Furthermore, the second micro-optical representation arrangement can have asymmetrical diffraction structures or matt-structured grating images.

The formation with a multiplicity of reflective facets can in particular be achieved by means of a sawtooth-like formation of a surface, e.g. an embossing lacquer layer and a corresponding Verspiegelungsbeschichtung be realized. The width of such saw teeth is preferably less than 300 μm, in particular less than 100 μm and particularly preferably less than approximately 20 μm. The height of the saw teeth is preferably less than 20 .mu.m, in particular less than 10 .mu.m and particularly preferably not greater than 5 microns.

In the case of the security element according to the invention, the visually perceptible motif can have exclusively the first and second motif part. Of course, it is also possible that the visually perceivable motif has more than two motif parts, for example three, four, etc. In this case, it is preferred that corresponding micro-optical representation arrangements are present in the further motif parts, with which a three-dimensional representation with absolute depth information , a reflective surface, which appears arched over the actual macroscopic spatial form, or a viewing angle-dependent movement, tilting and / or alternating effect is provided with or without three-dimensional effect.

In the case of the security element according to the invention, the support may have a foil and at least parts of the two microoptical representational arrangements may be realized by means of the same foil.

The security element can be designed as a multilayer composite layer.

The security element can in particular have a first and second embossing lacquer layer, between which a carrier layer is preferably arranged. The first and second embossing lacquer layer and the possibly provided carrier layer can form the carrier of the security element.

In an advantageous embodiment, microimage elements of the first microoptical representation arrangement and microscopic structures, for example sawtooth structures or Fresnel structures, of the second microoptical representation arrangement are embossed in the first embossing lacquer layer, the microscopic structures being provided with a reflection-enhancing coating. Microstructures of the first microoptical representation arrangement are embossed in the second embossing lacquer layer, which micrographs are magnified by means of the microimaging optical system in order to present the viewing angle-dependent at least two different images. The microimage elements may be refractive or reflective elements. If they are reflective elements, they are also preferably provided with a reflection-enhancing coating. Preferably, the application of the coating is performed in one step for the microimage elements and the microscopic structures.

Furthermore, it is possible to form the microscopic structures of the second microoptical representation arrangement not in the first embossing lacquer layer but in the second embossing lacquer layer (including the reflection-enhancing coating).

Alternatively, it is also possible to provide a third embossing lacquer layer in which the microscopic structures are embossed and provided with the corresponding reflection-enhancing coating. The third embossing lacquer layer can be connected to the second embossing lacquer layer via a second carrier layer.

Furthermore, the microstructures to be imaged may be embossed not only in the region of the first motif part but also in the region of the second motif part. This facilitates the production and leads to further interesting optical effects that are difficult to imitate.

The multilayer composite of the security element preferably has a total thickness of less than 500 μm, in particular less than about 100 μm and particularly preferably less than 50 μm.

The invention also includes a value document with a security element of the type just mentioned, including its developments.

The security element can be designed, in particular, as a security thread, tear-open thread, security strip, security strip, patch or as a label for application to a security paper, value document or the like. In particular, the security element can span transparent or at least translucent areas or recesses.

The term security paper is understood here in particular as the precursor that can not yet be processed to form a value document, which may also have further authenticity features in addition to the security element according to the invention. Value documents are here understood, on the one hand, documents produced from security papers. On the other hand Value documents may also be other documents and objects that can be provided with the security element according to the invention, so that the value documents have non-duplicable authenticity features, as a result of which an authenticity check is possible and at the same time unwanted copying is prevented.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the specified combinations but also in other combinations or alone, without departing from the scope of the present invention.

Figur 1

eine Draufsicht einer Banknote mit einem erfindungsgemäßen Sicherheitselement;

Figur 2

eine vergrößerte Draufsicht des Sicherheitselementes von Figur 1;

Figur 3

eine Querschnittsansicht des Sicherheitselementes von Figur 2;

Figur 4

eine schematische Ansicht zur Erläuterung der Funktionsweise der ersten mikrooptischen Darstellungsanordnung;

Figur 5

eine schematische Ansicht zur Erläuterung der Funktionsweise der zweiten mikrooptischen Darstellungsanordnung;

Figuren 6A - 6C

Darstellungen des erfindungsgemäßen Sicherheitselementes unter unterschiedlichen Betrachtungsrichtungen;

Figuren 7A - 7C

Ansichten des erfindungsgemäßen Sicherheitselementes unter gleichem Betrachtungswinkel aber mit unterschiedlichen Beleuchtungsrichtungen;

Figur 8

eine Schnittansicht einer weiteren Ausführungsform des erfindungsgemäßen Sicherheitselementes;

Figur 9

eine Schnittansicht einer noch weiteren Ausführungsform des erfindungsgemäßen Sicherheitselementes;

Figur 10

eine Schnittansicht einer anderen Ausführungsform des erfindungsgemäßen Sicherheitselementes;

Figur 11

eine Vorderansicht einer weiteren Ausführungsform des erfindungsgemäßen Sicherheitselementes, und

Figur 12

eine Rückansicht des erfindungsgemäßen Sicherheitselementes von Figur 11.

The invention will be explained in more detail by way of example with reference to the accompanying drawings, which also disclose features essential to the invention. For better clarity, a scale and proportioned representation is omitted in the figures. Show it:

FIG. 1

a plan view of a banknote with a security element according to the invention;

FIG. 2

an enlarged plan view of the security element of FIG. 1 ;

FIG. 3

a cross-sectional view of the security element of FIG. 2 ;

FIG. 4

a schematic view for explaining the operation of the first micro-optical representation arrangement;

FIG. 5

a schematic view for explaining the operation of the second micro-optical representation arrangement;

Figures 6A-6C

Representations of the security element according to the invention under different viewing directions;

FIGS. 7A-7C

Views of the security element according to the invention under the same viewing angle but with different lighting directions;

FIG. 8

a sectional view of another embodiment of the security element according to the invention;

FIG. 9

a sectional view of a still further embodiment of the security element according to the invention;

FIG. 10

a sectional view of another embodiment of the security element according to the invention;

FIG. 11

a front view of another embodiment of the security element according to the invention, and

FIG. 12

a rear view of the security element of the invention FIG. 11 ,

At the in FIG. 1 In the embodiment shown, the security element 1 according to the invention is integrated in a banknote 2 in such a way that the security element 1 differs from the security element 1 shown in FIG FIG. 1 shown front side of the banknote 2 is visible.

The security element 1 is designed as a reflective security element 1 with a rectangular motif area 3 which is divided into a first motif part 4 and a second motif part 5.

The first motif part 4 surrounds here the second motif part 5, such as the enlarged representation in FIG FIG. 2 can be seen.

As in particular in the schematic sectional view of the motif area 3 in FIG. 3 3, the motif area 3 has a carrier foil 6 (which can be, for example, a PET foil) and an upper and lower embossing lacquer layer 7, 8. In the lower embossing lacquer layer 8, microstructures 9, which in particular can be filled with color, are arranged in a plane perpendicular to the plane of the drawing FIG. 3 in a grid with a fixed geometry (here, for example, a hexagonal grid) and thus arranged flat in a first microstructure pattern. Alternatively to the production in an embossing lacquer layer, the microstructures 9 can also be realized in another way on the carrier foil 6. In particular, printed microstructures are also conceivable. In addition, the microstructures 9, as in the WO2009 / 083151 A1 may also be formed by metallized sub-wavelength structures, in particular sub-wavelength gratings or moth-eye structures or produced by transfer of metallic structures, as described, for example, in the German patent application DE 102010019766.1 is described.

The upper embossing lacquer layer 7 is designed such that it has a multiplicity of microlenses 10 in the first motif part 4. The microlenses 10 are in a plane perpendicular to the plane of FIG. 3 in a grid with fixed geometry (here, for example, a hexagonal grid) and thus flat in In the exemplary embodiment, the first pattern is matched to the first microstructure pattern and both patterns are aligned with respect to one another such that, when the security element 1 is viewed, the microlenses 10 together with the microstructures 9 form a moiré magnification arrangement. The basic principle of a moire magnification arrangement is for example in WO 2007/076952 A2 described, the entire contents of which are hereby incorporated.

The moiré magnification arrangement in the region of the first motif part 4 forms a first micro-optical representation arrangement 11, with which the number 105 is repeatedly shown to the viewer behind the plane of the banknote 2, as will be described in detail below. This is achieved by presenting to the left and right eyes LA and RA of the observer different views of the object to be displayed (here the number 105), which show the object in each case viewed from the corresponding direction. In FIG. 4 the object is drawn as a point for simplification of the representation, wherein the right eye RA of the user sees the object at the position 12 and the left eye LA of the user sees the object at the position 13. Thus, the viewer sees with his two eyes the object under the different directions 14,15, which intersect at the position 16, so that the object is located at the position 16 and therefore at a distance d1 behind the banknote 2 for the viewer. For the viewer, this results in absolute depth information for the object.

In the region of the second motif part 5, a second micro-optical representation arrangement 17 is formed, which in the exemplary embodiment has a multiplicity of mirrored facets 18 in the upper embossing lacquer layer 7. However, instead of mirrored facets 18, the embossing lacquer layer may also be other embossed structures, in particular refractive Fresnel structures with varying grating period, asymmetric diffraction structures or domed matt-structured grating images included. With the second micro-optical representation arrangement 17, a reflective surface is presented to the observer, which appears arched in relation to the actual macroscopic spatial form of the second micro-optical representation arrangement 17. As the schematic representation in FIG. 5 to explain the principle of the second micro-optical representation arrangement 17, incident light is reflected at the facets 18 in the same directions in which a curved surface 19 would reflect the light.

Thus, the incident light beam 20 is reflected in the direction 21, which is parallel to the direction 21 ', which would correspond to the direction of reflection at the surface 19. The same applies to the light beams 22 and 24, which are reflected in the directions 23 and 25. These directions 23 and 25 are parallel to the directions 23 'and 25', which would be the reflecting directions when reflected at the surface 19.

The facets 18 are dimensioned so that an observer can not dissolve them without aids. Thus, the facets 18 can have dimensions of, for example, 15 μm and a height of, for example, 5 μm in the direction perpendicular to the plane of the drawing.

From the reflection behavior of the second micro-optical representation arrangement 17, a viewer concludes that in the second motif part 5 there is the curved surface 19 with the depth d2. For example, for the light beam 20, the reflection behavior indicates that the local surface normal points in the direction 26, which is clearly different from the macroscopic one Surface normal (arrow 27) of the second micro-optical representation 17 in this area. By means of the second micro-optical representation arrangement 17, a curvature is thus imitated by directional reflection, whereby only indirectly does a depth impression or a 3D impression result. Therefore, this impression can also be called "2½" dimensional representation or relief-like representation.

In particular, no parallax is generated by means of the second micro-optical representation arrangement 17, so that the impression of depth is based essentially on the experience of the observer, which implicitly requires further information. If a viewer sees a surface arched forward, the observer will conclude that the center area of the arched area must, from his perspective, be further ahead than the edge area.

In the exemplary embodiment described here, a head of a woman is represented by means of the second micro-optical representation arrangement 17.

In Figures 6A, 6B and 6C the security element 1 is shown as it appears to a viewer at different viewing angles, provided that the security element 1 is illuminated in such a way that the observer stands in each case in the mirror reflex of the light source. Under this assumption, the view of the female portrait in the second motif part 5 always remains the same, while due to the parallax the depthwise representation of the numbers 105 shifts horizontally from left to right. So is in the view from the left according to FIG. 6A the number 105 marked with the arrow P1 to the left of the neck of the female portrait. In the central view according to FIG. 6B The number 105 is just beginning to disappear behind the portrait of a woman. When viewing from the right according to FIG. 6C the number 5 of the number 105 is already no longer visible.

Thus, the first micro-optical representation arrangement 11 provides different images as a function of the viewing angle, while the representation of the second micro-optical representation arrangement 17 does not depend on the viewing angle with respect to its spatial effect. The first micro-optic display assembly 11 provides more than two different views of the numbers 105 in such a way that the described movement of the numbers 105 relative to the female portrait results when the viewing direction changes. There is thus a parallax.

In Figures 7A, 7B and 7C If the security element 1 according to the invention is shown from the front, in each case in the same viewing direction, the position of the light source and thus the direction of illumination varies. In FIG. 7A the security element 1 is illuminated from the left. In FIG. 7B the security element 1 is illuminated from the front and in FIG. 7C the security element 1 is illuminated from the right. From the representations of FIGS. 7A-7C It is clear that the woman portrait and thus the second part of the subject 5 reflects the light according to the curvature of the trailing head. However, the positions of the in-depth numbers 105 (arrow P1) do not change because the viewing direction and thus the viewing angle have not changed. In practice, the position of the light source will be fixed and an observer will conclude from the position of the light reflections and their movement when tilting the security element to the shape of the trailing curvature.

The first micro-optical display device 11 thus provides in this embodiment, with constant viewing angle independent of the illumination direction representation, while the representation of the second micro-optical representation arrangement 17 varies according to the imitated reflective and relief-like training of the female portrait.

In the embodiment described, an absolute depth effect is thus achieved by means of the moiré magnification arrangement 11, in which the observer is shown the periodically recurring number 105 lying in the depth d1. The microstructures 9 may, as already mentioned, preferably be filled with color, so that the numbers 105 on the one hand and the remaining area of the first motif part 4 on the other appear dull, but of different colors. In front of this first motif part 4 there is the second motif part 5, in which an arched, metallic-looking female portrait is shown via an arrangement of metallized microscopic sawtooth gratings.

The first micro-optical magnification arrangement 11 may be designed not only as a moiré magnification arrangement, but also, for example, as a modulo magnification arrangement, such as in the WO 2009/000528 A1 is described. The content relating to the formation of a modulo magnification arrangement of WO 2009/000528 A1 is hereby incorporated into the present application. With a modulo magnification arrangement, unlike a moiré magnification arrangement, the image to be displayed need not necessarily be composed of a grid of periodically repeating individual motifs. It can be displayed a complex frame with high resolution. In the moiré magnification arrangement, the image to be displayed usually consists of individual motifs (in this case microstructures 9) which are periodically arranged in a grid and which are enlarged by the lenses 10, the area associated with each individual motif being at most approximately the area of the corresponding lens cell equivalent.

In the described embodiment, the microlenses 10 and the sawtooth structure for the reflective facets can be produced simultaneously by means of only a single embossing of the embossing layer 7. Subsequently, only the facets are to be metallized so that they appear reflective. The structure according to FIG. 3 is therefore fast to produce.

Instead of the sawtooth arrangement described, Fresnel structures or relief adjustments by diffractive structures or matt-structured grid images can also be used in the second micro-optical representation arrangement 17.

In FIG. 8 a modification of the security element 1 according to the invention is shown, in which the first micro-optical representation device 11 instead of the microlenses 10 concave mirror 28, which are formed by embossing the lower embossing lacquer layer 8 and applying a reflective coating.

The second micro-optical representation arrangement 17 embodied as facets 18 in the exemplary embodiment is also formed on the lower embossing lacquer layer 8. The facets 18 can be formed in the same way as the micro-concave mirrors 28 by embossing and mirroring.

The microstructures 9 can be provided not only in the region of the first motif part 4, but also in the region of the second motif part 5 and thus above the facets 18. This facilitates the production of the security element. 1

If the microstructures 9 are provided in the region of the second motif part 5 and filled with a color, the curved reflective surface, which is adjusted by the facets 18, also appears slightly colored. However, if the coloring of the curved specular surfaces is not desired, the microstructures 9 in this range may be omitted. In FIG. 9 a structure of the security element 1 is shown, in which the micro hollow mirror 28, the microstructures 9 and the facets 18 are each embossed in a separate embossing lacquer layer 8, 7 and 29. Between the embossing lacquer layers 8 and 7 there is provided a first carrier foil 6 and between the embossing lacquer layers 7 and 29 a second carrier foil 30 is provided.

Although this structure requires more steps for production compared to the variants according to Figures 3 and 8th However, it offers the advantage that the origination of the micro-cavity mirrors 28 and the facets 18 can take place separately from each other. The micro-cavity mirrors 28 may be the same even in different designs since only one homogeneous area covered with micro-mirrors 28 is needed. Once you have made an original with very good imaging properties, you can use it to make many different security features. In addition, for the production of corresponding security elements with different motifs in each of the first and second micro-optical representation arrangements 11, 17, the same embossing tool can be used for embossing the micro-cavity mirrors 28, so that this also has to be produced only once. Furthermore, the micro-hollow mirrors 28 and the facets 18 can be metallized differently, for example with different metals or coatings with color-shifting effects (eg thin-film systems in which the color varies depending on the viewing angle).

A particular advantage of the construction FIG. 8 is that both the micro hollow mirror 28 and the facets 18 are mirrored, while, for example, in the in FIG. 9 shown construction is a partial demetallization in the adjacent to the second micro-optical representation assembly 17 areas necessary. The sharpness of the boundary between the two motif parts 4, 5 is then given by the corresponding tolerances of demetallization. This limitation is in the structure according to FIG. 8 not before, so that the curved surface in the second motif part 5 with a particularly filigree outline against the background of moire or modulo magnification arrangement in the first motif part 4 may appear.

In the variants according to FIGS. 8 and 9 with micro-hollow mirrors may also advantageously on the top and / or bottom of the security element 1, a further protective lacquer layer (not shown) may be provided so that the resistance and protection against impressions can be increased by counterfeiters.

In particular, when viewing the security element 1 in transmitted light in front of a bright light source, the first micro-optical representation assembly 11 instead of a Mikrofokussierelementerasters (grid of the microlenses 10 or grid of the micro-hollow mirrors 28) also have only a breadboard 31, as in FIG. 10 is shown. Such a perforated grid 31 can be realized for example by periodically arranged holes or slots in an opaque, for example, mirror-metallized layer. The holes can be small recesses. In this case, the holes may be referred to as positive holes. It is also possible to provide so-called negative holes in which the holes are small, non-transparent or non-reflective areas.

At the in FIG. 10 In the embodiment shown, the breadboard also extends into the second motif area 5, so that a superimposition of the representations results in the second motif area. Of course, the security element can also be designed so that no hole pattern is present in the second motif area 5.

Furthermore, in the case of the security element 1 according to the invention, both the first micro-optical representation arrangement 11 and the second micro-optical representation arrangement 17 can be realized by means of diffractive structures. Thus, in the first motif part 4, for example, a hologram with a stereographic 3D representation can be provided, which is constructed from microscopically small sinusoidal gratings. In the second motif part 5 asymmetric diffraction gratings are preferably arranged so that the reflection behavior of a curved surface (if possible) is adjusted achromatisch, as for example in the WO 2006/013215 A1 is described, the relevant disclosure of which is hereby incorporated.

As already in connection with FIG. 10 is described, the two motif parts 4 and 5 may overlap at least partially. Alternatively or additionally, the two motif parts 4 and 5 can also be interleaved in some areas. In this case, the surfaces of the two motif parts 4, 5 can be decomposed, for example, into complementary surface elements and subsequently combined to form an overall motif. Each motif part loses part of its image information, which is replaced in the affected area elements by the image information of the other surface element. If the dimensions of the surface elements are below the resolution of the eye, the viewer perceives the individual impressions of the two parts of the subject at the same time and processes them into an overall motif. The area proportions of the area elements originating from both motif parts can be distributed locally and / or globally the same or different. If there is an unequal distribution, the motif part with the larger area proportion can visually dominate with respect to the motif part with the smaller proportion. In general, it is also possible to use surface elements that are above the resolution of the eye. In this case, the viewer can perceive the individual parts of the subject locally.

In an embodiment in which the first micro-optical display device 11 is configured as a moire magnification device having microlenses 10 and the second micro-optical imaging device 17 comprises the reflective facets 18, e.g. in the interleaved region, every second microlens 10 of the first microoptical representation arrangement 11 is replaced by one or more reflective facets 18 of the second microoptical representation arrangement 17.

Furthermore, the motif area 3 of the security element 1 can be divided, for example, into small tiles or thin strips which are each covered with elements of the first or second micro-optical representation arrangement 11, 17. This results in an interesting effect, since the representation of the second motif part 5 is no longer purely metallic mirroring, but partially transparent, so that you see through the second micro-optical representation 17 through an example lying in depth image of the first part of the motif 4. Alternatively, the object represented by means of the first micro-optical representation arrangement 11 may also seem to lie or float in front of the domed surface of the second micro-optical representation arrangement 17.

Depending on the areal proportion of the first and second microoptical display arrangements 11, 17, it is possible to change continuously from a metallically glossy, opaque curvature to an increasingly transparent and finally rather glassy appearance.

The first and / or second micro-optical representation arrangement (s) 11, 17 can / may be wholly or partially provided with a color-shifting coating, in particular a thin-film system with reflector / dielectric / absorber. This further enhances the visual attractiveness and further increases the security against counterfeiting.

The security element 1 according to the invention can be arranged on the banknote 2 in such a way that it not only depends on the in FIG. 1 shown front side, but also from the back of the banknote is visible. However, this does not necessarily mean that all generated curvature or depth effects must be visible from both sides.

An advantageous embodiment is in Figures 11 (Front view) and 12 (rear view). In the first motif part 4, the security element 1 has a first micro-optical representation 11 according to FIG FIG. 8 which here represents the number 105 periodically repeated in depth. In the second motif part 5 a vaulted appearing representation of a portrait is visible, the representation of both sides (ie also from the back according to FIG. 12 ) appears arched. This can be done, for example, by means of facets 18 according to FIG FIG. 8 be realized. From the rear, however, the viewer looks in the region of the first motif part 4 on the back of the micro-cavity mirror 28 of the first micro-optical representation assembly 11, so that he can perceive there only a matte metallized area (in FIG. 12 Therefore, in the first part of the motif 4, the numbers 105 are not shown).

In order to make the security element 1 according to the invention more attractive from the rear, therefore, for example in a second motif area 32 adjoining the motif area 3, a further curved representation (here the number 1452) can be obtained by means of reflective facets in the same way as in FIG FIG. 8 be realized. The second motif area 32 and thus the number 1452 is here visible only from the back (from the front, the number would appear reversed). This can be achieved, in particular, by arranging the security element 1 in a window area of the banknote which is only as large as the motif area 3, so that the second motif area 32 is concealed and therefore can only be seen from the rear side.

In an advantageous manner, only specific areas in the first and second motif areas 3 and 32 can be selectively covered with a color-shifting thin-film system. Thus, for example, the second motif part 5 and the motif region 32 on the back ( FIG. 12 ) be coated with a color-shifting thin-film system, so that these elements then appear with changing color in front of the metallic matte and colorless background of the micro hollow mirror backs in the first motif area 4.

Of course, the security element 1 according to the invention can be developed such that both the bulging and the depth effect can be seen from both sides of the security element 1.

In the exemplary embodiments described so far, the first micro-optical representation arrangement 11 in the first motif part 4 was in each case designed such that a stereographic representation with depth information is achieved. These are understood here as representations in which a three-dimensional Effect is generated by the security element 1 provides the left and right eye of the observer different views of an object, which show the object viewed in each case from the corresponding direction. From these different views, an absolute depth information then results for a viewer, resulting in a total of three-dimensional impression. The representations used in this class can often have more than just two different views, which usually results in a parallax (ie when turning or east-west tilting the image components move in the foreground relative to the image components in the image background). Under certain circumstances, for example, you can also look behind an object standing in the foreground by turning.

This can be realized technically by three-dimensional holograms, for example directly exposed holograms or computer-generated stereograms. Further examples are microlens tilt images and Moire magnification arrangements with depth effect and / or motion effect, as eg in WO 2007/076952 A2 or WO 2009/000527 A1 is described.

In the second micro-optical representation arrangement 17 in the second motif part 5, a curvature is imitated by directional reflection, from which only indirectly a depth effect or a three-dimensional effect results. In this type of representations, no parallax is shown, so that a representation in front of or behind a reference plane is not readily possible. For this class of representation can be, for example, lens-like arched reflective Fresnel structures (eg EP 1570 422 B1 . EP 1 562 758 B1 ), diffractive achromatic elements with arching effect (eg WO 2006/013215 A1 ), dull appearing matte structure grids (eg WO2010 / 034420A1 ) or in particular also relief-like appearing security elements based on micro-optical sawtooth count, as in connection with FIG. 5 for example, described in the present application. Common to all these embodiments is that an at least partially mirrored surface, which is practically flat on a larger scale, violates the law implicitly assumed by the observer that the angle of incidence equals the angle of reflection, on a larger scale of lengths, for example, by aligning locally with micromirrors that are invisible to the naked eye deviates from the respective surface normal of the visible to the viewer reference plane of the security element and / or the incident light is diffracted by diffraction effects in the viewer unexpected directions.

In a further refinement, the first micro-optical representation arrangement 11 can now be formed in such a way that in the first motif part 4 the parallax does not exactly correspond to the parallax of an object lying in the depth. This can be realized, for example, by moire magnification arrangements or modulo magnification arrangements. It can thereby be achieved that when tilting or turning the security element 1, an additional movement effect in the first part of the motif 4 occurs. This can be an orthoparallactic movement, as they are eg in the WO 2007/076952 A2 Strictly speaking, the representations for the left and right eyes of the observer allow no allocation of a depth, since the viewing directions, under which the observer sees the object with the left and right eye, do not intersect. In a preferred variant, there is only a relatively small error of the parallax, so that the viewing directions (14 and 15 in FIG Fig. 4 ) almost cut and the viewer a while tilting or turning the security element 1 moving Object sees, but he clearly despite the parallax error, for example, in a lying behind the plane of the security element 1 depth.

In the A-matrix formalism of the application WO 2009/000528 A1 corresponds to a representation with correct parallax of a representation with an A-matrix, which is occupied only on the main diagonal. In an orthoparallactic representation, the A-matrix is occupied only at the positions not lying on the main diagonal. A small error of parallax in the sense of the present invention is when the A-matrix is occupied both on the main diagonal and next to it.

Similar to the specific embodiments of moiré or modulo magnification arrangements described above, the parallax does not exactly correspond to the parallax of a deep-lying object, so that in extreme cases an orthoparallactic movement arises, the second micro-optical representation arrangement can also have "errors" in the orientations have the microscopic structures compared to the orientation of the trailing surface. Such an effect is present, for example, in a so-called imaginary area. This is understood to mean here the formation of a reflection or transmission behavior which can not be produced with a real curved reflecting or transmitting surface. For example, if you turn the azimuth angles of all facets 90 ° to the right, a relief illuminated from above looks like it is illuminated from the right. Furthermore, the light reflections do not migrate when tilted in this case, as you would expect the nachstellt relief, but also "orthoparallaktisch", which can be a very surprising effect. Such a viewer, however, also appears arched at first glance. For the inventive impression of a curvature, it is therefore not important that the orientation In fact, the microstructures inevitably replicate the reflection behavior of a real curved surface.

In a further embodiment of the security element 1, the representation can change from a first image into a second image by means of the first micro-optical representation arrangement 11 in the first motif part 4 in the case of an east-west tilting or rotation of the security element 1. Thus, for example, a deep-lying image of a first symbol A could tilt into at least one other representation, for example a symbol B, when the security element 1 is tilted.

In addition to a three-dimensional effect, the first micro-optical representation arrangement 11 can also realize additional effects, for example, in addition to the tilting images mentioned above, also kinematic effects (movements, pumping effect, etc.). In the case of the modulo magnification arrangements already mentioned, the three-dimensional representation in the first motif part 4 can move when tilting the security element 1. Alternatively, the representation could also tilt from a certain tilt angle in the representation of a completely different, not necessarily three-dimensional appearing object (for example, a lying in the depth number in another representation, for example, a further tilting then moving symbol, change).

The quality or the appearance of the two micro-optical representation arrangements can each show a different dependence on the viewing or lighting situation used. For example, a stereogram realized by a hologram grating is easily recognizable from the right direction only in the case of almost parallel illumination, while it is blurred or not perceived under diffuse illumination becomes. However, the second micro-optical representation arrangement, which appears arched in accordance with the invention, is very easily recognizable even with diffuse illumination from a wide angular range. Other combinations can show in plan view and clearly recognizable first and second micro-optical representational arrangements. The first micro-optical representation arrangement can consist, for example, of a moire magnification arrangement based on a microlens grid which, for example, exhibits a depth effect when viewed and viewed, while a second micro-optical representation arrangement formed by metallized sawtooth structures shows the desired curvature effect in plan view and can only appear opaque when viewed , The security element according to the invention can consequently be designed such that, depending on the viewing and / or illumination situation, the representation of one of the two microoptical representation arrangements dominates, while the representations in another viewing or illumination situation complement one another to form an overall motif.

The security element 1 according to the invention can also be designed, for example, as a security strip 33, as in FIG FIG. 1 is shown. Furthermore, the security element 1 can not only, as described, be formed on a carrier film, from which it can be transferred to the value document 2 in a known manner. It is also possible to design the security element 1 directly on the value document. Thus, a direct pressure on a polymer substrate with subsequent embossing of the security element can be carried out, for example, to form a security element according to the invention in the case of plastic banknotes. The security element according to the invention can be formed in a wide variety of substrates. In particular, it may be in or on a paper substrate, a paper with synthetic fibers, ie paper with a proportion x of polymeric material in the range of 0 < x <100 wt .-%, a plastic film, z. As a film of polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polypropylene (PP) or polyamide (PA), or a multilayer composite, in particular a composite of several different films (composite composite) or a paper-film composite (foil / paper / foil or paper / foil / paper), wherein the security element can be provided in or on or between each of the layers of such a multilayer composite.

In the exemplary embodiments described so far, it has been tacitly assumed that the micro-optical representation arrangements are located on planar substrates. However, the inventive designs can also be used to advantage in curved or flexible substrates, such as labels, securities, or banknotes.

Illustrative embodiments:

• Embodiment 1: Security element for a security paper, value document or the like, having a carrier which has a motif area (3) which provides a visually perceptible motif with a first and a second motif part (4, 5), wherein the motif area (3) has a first micro-optical representation arrangement (11), which presents at least two different images as a first motif part, and a second micro-optical representation arrangement (17), which presents as a second motif part (5) a reflective surface which is opposite to the actual macroscopic spatial form of the second micro-optical representation arrangement (17) appears arched.
• Embodiment 2: Security element according to embodiment 1, in which the two motif parts are arranged coherently, the two motif parts (4, 5) preferably bordering one another directly.
• Embodiment 3: Security element according to one of the above embodiments, in which one of the two motif parts (4, 5) at least partially surrounds the other of the two motif parts (4, 5).
• Embodiment 4: Security element according to one of the above embodiments, in which the two motif parts (4, 5) at least partially overlap and / or are at least partially interleaved with one another.
• Embodiment 5: Security element according to one of the above embodiments, in which the first micro-optical representation arrangement (11) presents the at least two different images in such a way that the images overlap at least in regions and / or are nested one inside the other.
• Embodiment 6: Security element according to one of the above embodiments, in which the first micro-optical representation arrangement (11) presents as the at least two different images different views of the same object.
• Embodiment 7: Security element according to one of the above embodiments, in which the first micro-optical representation arrangement (11) presents the at least two different images in such a way that a viewer obtains a stereographic representation of an object with absolute depth information.
• Embodiment 8: Security element according to one of the above embodiments, in which the first micro-optical representation arrangement (11) is designed as a hologram.
• Embodiment 9: Security element according to one of embodiments 1 to 7, in which the first microoptical representation arrangement (11) comprises microstructures (9) and microimage elements (10, 28) in order to image the microstructures (9) in an enlarged manner.
• Embodiment 10: Security element according to one of the above embodiments, in which the first micro-optical representation arrangement (11) generates an orthoparallactic representation.
• Embodiment 11: Security element according to one of the above embodiments, in which the second micro-optical representation arrangement (17) presents the reflective surface in a relief-like impression.
• Embodiment 12: Security element according to one of the above embodiments, in which the second micro-optical representation arrangement (17) has embossed microscopic structures which are provided with a reflection-enhancing coating.
• Embodiment 13: Security element according to embodiment 12, in which the second micro-optical representation arrangement (17) has a plurality of reflective facets (18) with mutually different orientations.
• Embodiment 14: Security element according to embodiment 12, in which the second micro-optical representation arrangement (17) has a reflective Fresnel structure with a varying grating period.
• Embodiment 15: Security element according to embodiment 12, in which the second micro-optical representation arrangement (17) has asymmetrical diffraction structures or matt-structured grating images.
• Embodiment 16: Security element according to one of the embodiments 12 to 15, in which the microimage elements of the first microoptical representation arrangement and the microscopic structures of the second microoptical representation arrangement are embossed in the same embossing lacquer layer.
• Embodiment 17: Security element according to one of the above embodiments, in which the security element (1) is designed as a multilayer composite layer.
• Embodiment 18: Value document with a security element according to one of the above embodiments.

LIST OF REFERENCE NUMBERS 1 security element 25 direction 2 bill 25 ' direction 3 Basic Zone 26 local surface normals 4 first part of the motive 27 macroscopic surface normals 5 second part of the motif 28 Micro concave mirror 6 support film 29 Embossing lacquer layer 7 upper embossing lacquer layer 30 second carrier film 8th lower embossing lacquer layer 31 breadboard 9 microstructures 32 Basic Zone 10 microlenses 33 security patrols 11 first micro-optical representation P1 arrow 12 position d1 distance 13 position d2 distance 14 direction 15 direction 16 position 17 second micro-optical representation 18 facets 19 surface 20 beam of light 21 direction 21 ' direction 22 beam of light 23 direction 23 ' direction 24 beam of light

Claims (16)

Security element for a security paper, document of value or the like, with
a carrier which has a motif area (3) which provides a visually perceptible motif with a first and a second motif part (4, 5), one of the two motif parts (4, 5) serving the other of the two motif parts (4, 5) at least partially surrounds,
wherein the motif area (3) comprises a first microoptical representation arrangement (11) which presents at least two different images as a first motif part depending on the viewing angle, and a second microoptical representation arrangement (17) which presents as a second motif part (5) a reflective surface opposite to the one The first microoptical representation arrangement (11) presents the at least two different images in such a way that a viewer can see a stereographic representation of an object with absolute depth information and / or an orthoparallactic representation of the object Object yields. Security element according to Claim 1, in which the two motif parts are arranged in a continuous manner, the two motif parts (4, 5) preferably bordering one another directly. A security element according to claim 2, wherein the distance of the two motif parts (4,5) is smaller than 1 mm. Security element according to one of the above claims, in which the two motif parts (4, 5) overlap at least partially and / or are at least partially interleaved with one another. Security element according to one of the above claims, in which the first micro-optical representation arrangement (11) is wholly or partially provided with a color-shifting coating, in particular with a thin-film system with reflector / dielectric / absorber. A security element as claimed in any one of the preceding claims, wherein more than two different images of the same object are presented by means of the first micro-optic representation such that parallax results. A security element according to any one of the preceding claims, wherein the first micro-optical display device (11) is formed as a hologram. A security element according to any one of claims 1 to 6, wherein the first microoptical display device (11) comprises microstructures (9) and microimage elements (10, 28) to image the microstructures (9) in an enlarged manner. A security element according to any one of the preceding claims, wherein the second micro-optical representation (17) presents the reflective surface in a relief-like impression. A security element as claimed in any one of the preceding claims, wherein the second micro-optical representation (17) is embossed microscopic Having structures which are provided with a reflection-enhancing coating. A security element according to claim 10, wherein the second micro-optic display assembly (17) comprises a plurality of reflective facets (18) having mutually different orientations. A security element according to claim 10, wherein the second micro-optical display device (17) comprises a refractory Fresnel structure with a varying grating period. A security element according to claim 10, wherein the second micro-optical display device (17) comprises asymmetric diffraction patterns or matt-structured grating images. A security element according to any one of claims 10 to 13, wherein the microimage elements of the first microoptical representation assembly and the microscopic structures of the second microoptical representation assembly are embossed in the same embossing lacquer layer. Security element according to one of the above claims, in which the visually perceptible motif has more than two motif parts, wherein microoptical representation arrangements are present in the further motif parts, with which a three-dimensional representation with absolute depth information, a reflective surface, which appears curved relative to the actual macroscopic spatial form , or a viewing angle-dependent movement, tilting and / or alternating effect with or without three-dimensional effect is provided. Security document with a security element according to one of the above claims.

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