AU2012331447B2 - Optically variable security element - Google Patents

Abstract

The invention relates to an optically variable security element (12) for security papers, value documents and other data carriers, with a substantially transparent carrier (20) having opposing first and second main surfaces (22, 24), an arrangement of micro-lenses (26) on the first main surface (22) of the carrier (20), and a laser-sensitive recording layer (32) arranged on the second main surface of the carrier (20). According to the invention, the micro-lens arrangement (26) is furnished with a laser-sensitive cover layer (28) having at least one cut-out (30) produced by the effect of laser radiation and extending over several micro-lenses (26), the laser-sensitive recording layer (32) comprises a plurality (34) of micro-markings (36) produced by the effect of laser radiation, wherein each micro-marking (36) is associated with one micro-lens (26) and is visible through the associated micro-lens (26) during inspection of the security element (12), and the plurality (34) of micro-markings (36) on the carrier (20) is arranged precisely aligned directly opposite the at least one cut-out (30).

Description

Optically Variable Security Element

Technical Field

The present invention relates to an optically variable security element for security papers, value documents and other data carriers, having a substantially transparent support having opposing first and second main surfaces, an arrangement of microlenses arranged on the first main surface of the support and a laser-sensitive recording layer arranged on the second main surface of the support. The present invention also relates to a method for manufacturing such a security element and a data carrier having such a security element.

Background Art

For protection, data carriers, such as value or identification documents, but also other valuable articles, such as branded articles, are often provided with security elements that permit the authenticity of the data carrier to be verified, and that simultaneously serve as protection against unauthorized reproduction.

Security elements having viewing-angle-dependent effects play a special role in safeguarding authenticity, as these cannot be reproduced even with the most modern copiers. Here, the security elements are furnished with optically variable elements that, from different viewing angles, convey to the viewer a different image impression and, depending on the viewing angle, display for example another color or brightness impression and/or another graphic motif.

For example, identification cards, such as credit cards or personal identity cards, have long been personalized by means of laser engraving. In personalization by laser engraving, the optical properties of the substrate material are irreversibly changed through suitable guidance of a laser beam in the form of a desired marking. Such a laser marking facilitates combining the individualization of the data carriers with security elements and integrating them into the print image more freely than in conventional individualizations, for instance in known numbering methods.

Document EP 0 219 012 A1 describes an identification card having a partial lens grid pattern. Through this lens pattern, pieces of information are inscribed in the card with a laser at different angles. Said pieces of information can also be subsequently perceived only at said angle, such that the different pieces of information appear when the card is tilted. A preferred aim of the present invention is to provide a security element of the kind cited above having an attractive visual appearance and high counterfeit security.

Summary of the Invention

In one broad form, the present invention provides an optically variable security element for security papers, value documents and other data carriers, the optically variable security element having a substantially transparent support having opposing first and second main surfaces, an arrangement of microlenses arranged on the first main surface of the support, and a laser-sensitive recording layer arranged on the second main surface of the support, wherein the microlens arrangement is provided with a laser-sensitive cover layer that has at least one gap that is produced by the action of laser radiation and that extends across multiple microlenses, the laser-sensitive recording layer has a plurality of micromarkings produced by the action of laser radiation, each micromarking being associated with a respective microlens and being visible when the security element is viewed through the associated microlens, and the plurality of micromarkings are arranged on the support in perfect register directly opposite the at least one gap.

Lenses whose size lies below the resolution Emit of the naked eye are referred to as microlenses. The microlenses are preferably developed to be spherical or aspherical and, for example in banknotes, advantageously exhibit a diameter between 5 pm and 100 pm, preferably between 10 pm and 50 pm, particularly preferably between 15 pm and 20 pm. For card applications, the microlenses can also be larger and exhibit, for example, a diameter between 100 pm and 300 pm. In all designs, the microlenses can also be developed as cylindrical lenses.

In all embodiments, the gap or gaps advantageously form a motif in the form of patterns, characters or a code. The gaps are preferably perceptible with the naked eye and especially exhibit a dimension between 0.5 mm and 3 cm. The distance between the cover layer and the recording layer is given by the thickness of the support and corresponds substantially to the focal length of the uncoated microlenses.

In a preferred embodiment, the micromarkings are formed by microholes in the recording layer, especially by substantially circular microholes or by pattern-shaped microholes. The exact shape of the micromarkings or microholes depends especially on the shape of the microlenses (spherical, aspherical, cylindrical) and, as described below, also on the angle of incidence of the laser radiation.

In other embodiments, the micromarkings can also consist in, instead of microholes in the recording layer, blackened or non-blackened changes in the visual appearance of the recording layer. In general, the micromarkings can be formed by a color change or removal of the laser-sensitive recording layer. The removal of the laser-sensitive recording layer also includes an only partial removal, which corresponds optically to a lightening. The color change or removal of the recording layer can be based on thermal, photochemical or composite processes. To produce transmitted light effects, the micromarkings exhibit a reduced opacity and, in the extreme case, are formed by the microholes mentioned. For reflected light effects, a reduced opacity is not absolutely mandatory, the change there can also consist in, for example, a blackening.

In some embodiments, the micromarkings are each smaller than their respective associated microlenses. Here, the ratio of the area of a micromarking to the area of its associated microlens can he below 1.0 or below 0.5, below 0.2, or even below 0.1.

Circular microholes can exhibit, for example, a diameter between 1 pm and 15 pm, between 1.5 pm and 5 pm, and especially between 2 pm and 3 pm.

The security element is particularly advantageously semitransparent in the region of the gaps and the opposing micromarkings, especially having a transmittance between 20% and 90%. In any case, the transmittance of the security element is significantly higher in the region of the gaps than in the regions still provided with the cover layer, which are typically opaque or have a transmittance of less than 15%, especially of less than 10%. In this way, the security element exhibits a conspicuous see-through effect, as described in greater detail below.

In preferred embodiments, the micromarkings are introduced into the recording layer through the microlens arrangement from at least two different directions with laser radiation. When viewed later, the micromarkings are then each perceptible substantially from viewing directions corresponding to the directions from which the micromarkings were introduced upon production. Accordingly, in the present embodiment, the micromarkings are perceptible from at least two different viewing directions, such that tilt or alternating images can be produced. The motifs that are visible from different viewing directions can be associated in meaning and, for example, as in a flip-book, depict an image sequence that proceeds before the eye of the viewer when the security element is tilted. If a certain portion of the motifs remains unchanged at all viewing angles, this region can also be executed as a gap region in the recording layer.

The angle of introduction, and thus also of viewing, can also vary continuously across the dimension of a gap, variations in one or in two spatial directions being able to be considered. When viewed, the degree of transparency, and thus the brightness in transmitted light, then changes continuously with the viewing angle, as described in greater detail below.

In an advantageous variant of the present invention, the cover layerhas, in addition to the gaps produced by the action of laser radiation, also blank regions that extend across multiple microlenses and that are not in register with directly opposing micromarkings. Such blank regions can be produced, for example, before the production of the micromarkings through a large-area removal of the cover layer, for example through a washing process or an etching process.

In this variant of the present invention, the gaps particularly advantageously form a first motif in the form of patterns, characters or a code. In the blank regions of the cover layer, further micromarkings produced by the action of laser radiation are present in the recording layer that form a second motif in the form of patterns, characters or a code. Also said further micromarkings are each associated with a respective microlens, are preferably smaller than the associated microlens, and are visible when the security element is viewed through the associated microlens. They can also exhibit the further properties mentioned for the first micromarking, especially with regard to shape and size of the micromarking.

When viewed in reflected light, only the first motif is perceptible, while, when viewed in transmitted light, the first and second motif are perceptible, the two motifs complementing each other to form a complete motif. The motif depiction, which is incomplete when taken alone, attracts attention in reflected light and prompts the viewer to view it in transmitted light in order to see the complete motif. The security element thus exhibits a high attention value and also offers high counterfeit security, since the special complement effect when switching from reflected light to transmitted light viewing can be reconstructed only with difficulty. If both motifs are produced in the same operation, the first and second motif are in perfect register with each other. Also the blank regions themselves can be developed in the form of a further motif.

In a further, likewise advantageous variant of the present invention, the recording layer exhibits, in addition to the micromarkings produced by the action of laser radiation, blank regions whose dimensions are larger than the dimension of the microlenses and that are not in register with directly opposing gaps. Also such blank regions in the recording layer can be produced, for example, through a washing process.

In this variant of the present invention, those fractional regions of the gaps that lie over the recording layer particularly advantageously form a first motif in the form of patterns, characters or a code, and those fractional regions of the gaps that lie over the blank regions form a second motif in the form of patterns, characters or a code. When viewed in transmitted light, both the first and the second motif are perceptible and the two motifs complement each other to form a complete motif. In advantageous embodiments, the first motif is not perceptible in reflected light, for example when the cover layer and the recording layer are chosen to match in color.

In yet a further advantageous variant of the present invention, the cover layer exhibits, in addition to the gaps produced by the action of laser radiation, blank regions that extend across multiple microlenses and that are not in register with directly opposing micromarkings. Directly opposing said blank regions of the cover layer, congruent blank regions are provided in the recording layer. Here, the blank regions in the cover layer and the recording layer are advantageously produced simultaneously by laser impingement by the same laser beam. For this, compared with the production of microholes described in another location, the laser energy is increased to such an extent that not only the cover layer, but also the recording layer is completely ablated.

Here, in a particularly advantageous embodiment, the gaps form a first motif in the form of patterns, characters or a code, and the blank regions of the cover layer form a second motif in the form of patterns, characters or a code. Then, when viewed in reflected light, only the second motif is perceptible while, when viewed in transmitted light, the first and second motif are perceptible and the two motifs complement each other to form a complete motif.

In advantageous embodiments of the present invention, the security element simultaneously includes a micro-optical depiction arrangement, especially a moire magnification arrangement, a moire-type micro-optical magnification arrangement, or a modulo magnification arrangement.

The basic principle of such micro-optical depiction arrangements is explained in document WO 2009/ 000528 Al, the disclosure of which is incorporated in the present description by reference. In this case, the recording layer preferably includes, in addition to the micromarkings, a motif image that is divided into a plurality of cells, in each of which are arranged imaged regions of a predetermined third motif, the microlens arrangement forming a microlens grid that, when the motif image is viewed, reconstructs the third motif from the imaged regions arranged in the cells.

In a preferred variant of the present invention, the recording layer, the cover layer or both layers are opaque. In particular, the recording layer and/or the cover layer can be formed by an opaque metal layer or include an opaque metal layer. Here, the term metal also includes metal alloys. Layers composed of aluminum, copper, chrome, silver, gold or an Al-Cu alloy, for example, may be considered as opaque metal layers. In some designs, there is to be a color contrast between the cover layer and the recording layer. In this case, aluminum, for example, is chosen as the material for the cover layer and copper as the material for the recording layer. In other designs, the cover layer and the recording layer are to appear to match in color. In this case, the same material is chosen for both layers, or materials of similar colors are chosen.

In addition to metal layers, also thin-film elements that have a color shift effect and that already lend the cover layer or the recording layer itself an optically variable appearance may be considered for the cover layer and the recording layer. Such thin-film elements typically consist of an absorber layer, a dielectric spacing layer and a metallic reflector layer. Here, the reflector layer is designed to be thin enough such that it can be provided with the desired gaps or microholes by the laser radiation.

In a further, likewise advantageous variant of the present invention, the recording layer, the cover layer or both layers are semitransparent, preferably each having a transmittance between 20% and 90%, especially between 40% and 80%.

According to a further, likewise advantageous variant of the present invention, the recording layer, the cover layer or both layers are formed by a laser-sensitive ink layer. Of course the possibilities mentioned can also be combined with one another, so for example the recording layer formed by a laser-sensitive ink layer, and the cover layer by an opaque metal layer.

In a further, likewise advantageous variant of the present invention, the cover layer is a transparent layer that changes the radius of curvature of the microlenses by at least 50%, especially a transparent layer that levels the microlenses. In this variant of the present invention, the recording layer can be opaque or semitransparent. The refractive index of the transparent layer is expediently on the order of magnitude of the refractive index of the microlenses, and especially differs therefrom by less than 0.3, preferably by less than 0.15.

According to a further embodiment of the present invention, the micromarkings are formed by microholes in the recording layer, and a reflection layer or a print layer is arranged on the recording layer. In this embodiment, the microholes advantageously exhibit a somewhat larger diameter of more than 5 pm, especially of more than 10 pm. In an advantageous variant of this embodiment, the reflection layer or the print layer has no microholes. The security element then displays, when viewed in reflected light, a tilt image in which the motif formed by the plurality of microholes is perceptible from a certain viewing angle in reflection or in reflected light, and disappears when the security element is tilted.

The present invention further provides a data carrier, especially a value document, such as a banknote, a passport, a certificate, an identification card or the like, that is furnished with a security element of the kind described. In an advantageous variant of the present invention, the security element can especially be arranged in or over a window region or a through opening in the data carrier.

In another, likewise advantageous variant of the present invention, the data carrier includes a data carrier substrate that has a marking region which is produced by the action of laser radiation and which adjoins at least one of the gaps produced in the security element by laser radiation and is in register therewith. In the marking region, the visual appearance of the data carrier substrate is changed. In particular, by the action of laser radiation, color components or metallic substances can be removed from the data carrier substrate, or the data carrier substrate can be foamed. In the latter case, to the visual change in the appearance is added a tangible marking. Due to the registered arrangement of the gap and the marking region, the security element is closely connected with the data carrier in a visually and, if applicable, also machine-detectable manner. As described in greater detail below, the registered arrangement is facilitated by the production of the gap and the marking region in the same operation with the same laser beam. In addition to the visual attractiveness, the data carrier joined with the security element in this way exhibits increased counterfeit security, since the security element cannot be applied anew in register after a removal from the data carrier. Any manipulation of the data carrier is thus easily perceptible, also for laypersons.

The gap and the marking region can especially form, together, a complete piece of information, such as a cohesive graphic depiction or a sequential alphanumeric character string. In the region of the gap, the security element is viewing-direction-dependently semitransparent such that that portion of the complete piece of information that lies in the gap is visible only from certain angles of view. The portion of the complete piece of information that lies in the marking region of the data carrier substrate, in contrast, is always visible. Thus, when the data carrier is tilted, from some angles of view, only a portion of the complete piece of information is visible, which is complemented from other angles of view to form the whole complete piece of information.

The present invention further provides a method for manufacturing an optically variable security element for security papers, value documents and other data carriers, in which a substantially transparent support having opposing first and second main surfaces is provided, an arrangement of microlenses being arranged on the first main surface of the support, a laser-sensitive recording layer is arranged on the second main surface of the support, the microlens arrangement is provided with a laser-sensitive cover layer, in the laser-sensitive cover layer is produced, by the action of laser radiation, at least one gap that extends across multiple microlenses, a plurality of micromarkings is produced in the laser-sensitive recording layer by the action of laser radiation, each micromarking being associated with a respective microlens and being visible through the associated microlens when the security element is viewed, and the plurality of micromarkings are arranged on the support in perfect register directly opposite the at least one gap.

Here, the gaps in the laser-sensitive cover layer and the opposing micromarkings in the laser-sensitive recording layer are advantageously produced in the same operation by the same laser beam. In some embodiments, the micromarkings can each be developed to be smaller than the associated microlenses.

In an advantageous method variant, the micromarkings are produced in the recording layer through the microlens arrangement from at least two different directions.

The present invention also provides a method for manufacturing a data carrier of the kind described above, in which a data carrier substrate is provided, a substantially transparent support having opposing first and second main surfaces is provided, an arrangement of microlenses being arranged on the first main surface of the support, a laser-sensitive recording layer is arranged on the second main surface of the support, the microlens arrangement is provided with a laser-sensitive cover layer, the support having the laser-sensitive recording layer, the microlens arrangement and the laser-sensitive cover layer is applied to the data carrier substrate, and in the same operation, by the same laser beam, by the action of laser radiation, a) at least one gap that extends across multiple microlenses is produced in the laser-sensitive cover layer, b) a plurality of micromarkings are produced in the laser-sensitive recording layer, each micromarking being associated with a respective microlens and being visible when the security element is viewed through the associated microlens, the plurality of micromarkings being arranged on the support in perfect register directly opposite the at least one gap, and c) in the data carrier substrate outside the region in which the support having the recording layer, the microlens arrangement and the cover layer is applied to the data carrier substrate, a marking region is produced that adjoins the cover layer at at least one of the gaps.

Through the action of the laser radiation, in the marking region, color components or metallic substances are preferably removed from the data carrier substrate, or the data carrier substrate is foamed.

The production of the gap and the plurality of micromarkings is preferably carried out with a first set of laser parameters and the production of the marking region is carried out with a second, different set of laser parameters. Such a procedure accounts for the fact that the production of the gaps and micromarkings can require different laser parameters, for example different levels of laser energy, than the production of the marking region. Here, at the sites at which the marking region adjoins a gap in the cover layer, the laser parameters of the laser beam are switched between the first and second set of laser parameters. Said switching can occur practically instantaneously, such that a precisely defined change in the laser parameters is achieved. Through the uninterrupted beam control, despite the variation in the laser parameters, a registered arrangement of the gap and the marking region is achieved.

In yet another form, the invention provides an optically variable security element for security papers, value documents and other data carriers, the optically variable security element having a substantially transparent support member having opposing first and second main surfaces, an arrangement of microlenses arranged on the first main surface of the support, a laser-sensitive cover layer disposed over the arrangement of microlenses, the laser-sensitive cover layer having at least one gap that is produced by laser radiation and that extends across multiple microlenses, and a laser-sensitive recording layer arranged on the second main surface of the support, the laser-sensitive recording layer having a plurality of micromarkings produced by laser radiation, each micromarking being associated with a respective microlens, such that when the security element is viewed, each micromarking is visible through its associated microlens, and wherein the plurality of micromarkings are located directly opposite the at least one gap and exclusively occupy an area which is congruent with the at least one gap.

Further exemplary embodiments and advantages of the present invention are explained below by reference to the drawings, in which a depiction to scale and proportion was dispensed with in order to improve their clarity.

Brief Description of the Drawings

Shown are:

Fig. 1 a schematic depiction of a banknote having an inventive optically variable security element that is arranged over a through opening in the banknote,

Fig. 2 schematically, the layer structure of a security element according to the present invention, in cross section,

Fig. 3 in (a) and (b), two intermediate steps in the manufacture of the security element in fig. 2,

Fig. 4 the visual appearance of the security element in fig. 2 when viewed from the front, in (a) in reflected light and in (b) in transmitted light,

Fig. 5 the visual appearance of the security element in fig. 2 when viewed from the back, in (a) in reflected light and in (b) in transmitted light,

Fig. 6 an exemplary embodiment in which the laser radiation upon the production of a gap encloses an angle Θ with the vertical line,

Fig. 7 a further exemplary embodiment of the present invention, in cross- section along the line VII-VII in fig. 8(a),

Fig. 8 the visual appearance of the security element in fig. 7 when viewed from the front, in (a) in reflected light and in (b) in transmitted light,

Fig. 9 a further exemplary embodiment of the present invention, in cross- section along the line IX-IX in fig. 10(a),

Fig. 10 the visual appearance of the security element in fig. 9, in (a) when viewed from the front in reflected light, in (b) when viewed from the same side in transmitted light, in (c) when viewed from the back in reflected light, and in (d) when viewed from the same side in transmitted light,

Fig. 11 in (a) to (d), a depiction as in fig. 10 for a modification of the security element in fig. 9,

Fig. 12 schematically, in cross-section, a security element according to the present invention that simultaneously forms a micro-optical display arrangement,

Fig. 13 an exemplary embodiment of the present invention, in which the cover layer is formed by a laser-sensitive transparent coating,

Fig. 14 an exemplary embodiment in which pattern-shaped microholes are produced in the recording layer,

Fig. 15 in (a) and (b), in each case, a top view of a recording layer having pattern-shaped microholes according to exemplary embodiments of the present invention,

Fig. 16 a further exemplary embodiment of the present invention, in cross section,

Fig. 17 the visual appearance of the security element in fig. 16 when viewed from the front, in (a) in reflected light and in (b) in transmitted light, and

Fig. 18 a further exemplary embodiment of the present invention that displays a tilt effect in reflected light.

Detailed Description of Embodiment(s) of the Invention

The invention will now be explained using the example of security elements for banknotes. For this, figure 1 shows a schematic diagram of a banknote 10 having an inventive optically variable security element 12 that is arranged over a through opening 14 in the banknote 10. In transmitted light, the security element 12 appears semitransparent in fractional regions 16 and can, due to its application over the opening 14, be viewed both from its front and from its back, in each case in reflected light and in transmitted light. The security element 12 shows, from said different viewing directions, different visual appearances in each case, as explained in greater detail below.

Figure 2 shows, schematically, the layer structure of the security element 12 according to the present invention, in cross section, with only the portions of the layer structure that are required to explain the functional principle being depicted. The security element 12 includes a substantially transparent support 20 that is typically formed by a transparent plastic foil, for example an about 20 μπι thick polyethylene terephthalate (PET) foil.

The support 20 exhibits opposing first and second main surfaces, the first main surface 22 being provided with an arrangement of microlenses 26. In the special exemplary embodiment, the microlenses 26 are arranged regularly in the form of a microlens grid and form on the surface of the support foil a two-dimensional Bravais lattice having a prechosen symmetry. The Bravais lattice of the microlenses 26 can exhibit, for example, a hexagonal lattice symmetry or also a lower symmetry, such as the symmetry of a parallelogram lattice.

The spherically or aspherically designed microlenses 26 preferably have a diameter between 15 pm and 30 pm and are thus not perceptible with the naked eye. The thickness of the support 20 and the curvature of the microlenses 26 are coordinated with each other in such a way that the focal length of the microlenses 26 substantially corresponds to the thickness of the support 20.

The microlens grid of the first main surface 22 is provided with an opaque, laser-sensitive cover layer 28 that, in the exemplary embodiment, is formed by a 50 nm thick aluminum layer.

Into the cover layer 28 were introduced, by the action of laser radiation, one or multiple gaps 30 that form a first motif in the form of patterns, characters or a code. Here, the gaps 30 extend across multiple, typically even across several thousand microlenses 26, since the gaps 30 are visible with the naked eye, and thus normally have dimensions of multiple millimeters. The security element 12 described with reference to figures 1 to 5 shows, for illustration, only a single gap 30 having the shape of a maple leaf 16. If the gap 30 has, for example, an area of 50 mm2, then, at a lens diameter of 25 pm, it extends across about 80,000 to 100,000 microlenses. It is therefore understood that the size ratios of microlenses and gaps in the drawings can be depicted only strongly exaggeratedly.

On the second main surface 24 of the support 20 is arranged a laser-sensitive recording layer 32 that, in the exemplary embodiment, is formed by a 60 nm thick copper layer.

Into the recording layer 32 was introduced, by the action of laser radiation, a plurality 34 of circular microholes 36 having a diameter of 2 pm to 3 pm. Even if the present invention is explained in greater detail below with reference to microholes, it is understood that, instead of microholes, also other micromarkings, such as color-changed regions in an ink layer, can be used.

The gaps 30 and the opposing microholes 36 are produced in the manner described in greater detail below simultaneously in the same operation and by the same laser beam, such that the gaps and the microholes exhibit no register tolerances to each other. In this way, the plurality 34 of microholes in the recording layer 32 are arranged on the support 20 in perfect register directly opposite the gaps 30 in the cover layer 28.

To manufacture the security element 12, the microlens grid that is present on the support 20 is first coated with a through, 50 nm thick aluminum layer 28, as shown in fig. 3(a). The second main surface 24 is coated with a through, 60 nm thick copper layer 32. At these layer thicknesses, both the aluminum layer 28 and the copper layer 32 are opaque. Due to the aluminum coating 28, the microlenses 26 are no longer optically effective in the coated regions.

The support 20 coated in this way is then impinged on from the side of the first main surface 22 with laser radiation 40, for example with the radiation of a Nd:YAG, NdiYVCh or fiber laser, and the aluminum layer 28 ablated in the shape of desired gaps 30. Here, the laser beam 40 can be pre-focused. Due to the ablation of the aluminum layer 28, the optical effectiveness of the microlenses 26 is restored in the region of the gaps 30. If, now, upon laser impingement, a laser energy is used that is higher than the energy required to demetalize the aluminum layer 28, then, after the ablation, a residual energy still remains that is focused by the now optically effective microlenses 26 onto the recording layer 32, as indicated in fig. 3(b) by the reference sign 42. If the laser energy is suitably chosen, the residual energy is not so high that the recording layer 32 under the microlenses 26 is completely ablated, but is sufficient to produce in the recording layer 32 microholes 36 whose dimensions are smaller than those of the associated microlenses 26.

Through this approach, it is achieved that, with each of the microholes 36 is associated a microlens 26 through which the microhole 36 is produced upon laser impingement, and through which the microhole 36 is visible when the security element is viewed later. In this way, the plurality 34 of microholes 36 is produced in perfect register and exclusively in the region of the respective opposing gaps 30. Due to the small dimensions of the microlenses 26 of only 20 to 30 μηι, it is additionally ensured that, from the normal viewing distance of 20 to 30 cm, the region of the gaps 30 is congruent with the region 34 provided with the plurality of microholes 36.

Figure 4 shows the visual appearance of the security element 12 produced in this way, when viewed from the side of the first main surface 22 (front), fig. 4(a) showing the appearance in reflected light, that is, in reflection, and fig. 4(b) the appearance in transmitted light, that is, in transmission.

In reflected light, outside the gap 30, the silvery-shining cover layer 28 composed of aluminum dominates the appearance. In the gap 30, the cover layer 28 is removed and the viewer sees there the copper color of the recording layer 32. Due to their small size, in reflected light, the microholes 36 in the recording layer 32 are perceptible with the naked eye only with difficulty or not at all, such that the recording layer 32 appears as a through metal layer. The viewer thus sees, in reflected light, a copper-colored maple leaf 16 against a silver-colored background, as illustrated in fig. 4(a).

When viewed in transmitted light, outside the gap 30, the security element 12 appears dark due to the opaque cover layer 28. In the interior of the gap 30, the recording layer 32, in contrast, is viewing-direction-dependently semitransparent due to the plurality 34 of microholes 36. Since, in this viewing direction, the microholes 36 are viewed through the microlenses 26, the microholes 36 are each perceptible substantially from that viewing angle from which they were introduced upon production with the laser beam 40. Furthermore, around said central viewing angle, the microholes 36 are perceptible in a certain angular range that depends mainly on the diameter of the microholes 36. Said diameter results, in turn, especially from the lens properties, above all from the focal length of the microlenses at the laser wavelength, the thickess of the support 20, the laser energy used and the layer thickness of the recording layer 32. Through suitable choice and coordination of said parameters, it is possible to set the diameter of the microholes 36, and thus the angular size of the visibility region, as desired within a broad range.

With reference to the depiction in fig. 4(b), the microholes 36 of the described exemplary embodiment were produced under vertical incidence of the laser radiation 40, as shown in fig. 3. The microholes 36 are thus also visible through the microlenses 26 when the security element 12 is viewed vertically, such that, from said viewing angle, the region of the gap 30 appears semitransparent in transmitted light. The viewer then sees a brightly shining maple leaf 16 against a dark background, as illustrated in fig. 4(b).

Figure 5 shows the visual appearance of the security element 12 when viewed from the side of the second main surface 24 (back), fig. 5(a) illustrating the appearance in reflected light and fig. 5(b) the appearance in transmitted light.

In reflected light, from the back, only the copper-colored recording layer 32 can be seen since, due to their small size, the microholes 36 are perceptible in reflected light with the naked eye only with difficulty or not at all. From the back, in reflected light, the viewer thus sees the through copper-colored metal layer, as shown in fig. 5(a).

Outside the gap 30, when viewed in transmitted light, the security element 12 appears dark due to the opaque recording layer 32. In the interior of the gap 30, the recording layer 32, in contrast, appears semitransparent in a large angular range due to the plurality 34 of microholes 36. Unlike the view from the front, when viewed from the back, the microholes 36 are not viewed through microlenses 26. Rather, the microlenses 26 collect the light incident from the first main surface 22 and focus it on the microholes 36, such that a wide angular range results in which the micro holes 36 on the back appear bright. The viewer thus sees a brightly shining maple leaf 16 against a dark background, as illustrated in fig. 5(b).

In the exemplary embodiment just described, the microholes were, for the sake of simpler illustration, introduced into the recording layer only from a single direction, specifically from a direction vertical to the main surfaces 22,24. However, the microholes of security elements according to the present invention are preferably produced in the recording layer through the microlens grid from at least two different directions. For instance, fig. 6 shows an exemplary embodiment in which, upon the production of a gap 30', the laser radiation 40 encloses an angle Θ with the vertical line 44. Te gap 30' practically does not differ from a gap 30 produced under vertical impingement, but the microholes 36' produced in the recording layer 32 are displaced from the lens center. Because of this, when viewed later, the microholes 36' are perceptible substantially only from a viewing angle that is inclined against the vertical by the angle Θ. Of course, here, too, a certain visility region around the angle 0 results that is given by the size of the microholes 36'.

Thus, by producing microholes 36 having different viewing angles 0, regions can be created that, in transmitted light, each become semitransparent from a different angle, such that a tilt image is created. Here, in some embodiments, each of the microholes 36, 36' exhibit, within a gap 30, 30', a constant viewing angle Θ30, Θ30', while the viewing angles of different gaps 30, 30' differ, in other words, Θ30 Φ Θ30. In other designs, there are already, within a gap 30, multiple microholes that are visible from different spatial directions.

In preferred embodiments, the introduction angle, and thus also the viewing angle Θ, varies continuously across the dimension of the gaps 30 in one or even in two spatial directions. Such a continuous change can be realized, for example, through a suitable deflection system for the laser radiation. When viewed in transmitted light, when the security element is tilted, the markedness of the semitransparency then changes continuously within the gap 30.

For example, the microholes 36 at the left edge of the gap 30 shown in figures 4 and 5 can be introduced vertically (introduction angle Θ = 0°) and at the right edge at an angle of Θ = 40°, the introduction angle Θ continuously increasing from 0° to 40° from the left edge to the right. When the front of the security element is viewed vertically in transmitted light, the left side of the maple leaf 16 then appears very bright, since there the viewer sees, through the microlenses 26, the microholes 36 that were introduced at a vertical angle. Toward the right edge of the maple leaf 16, the brightness continuously decreases since, with increasing angle Θ, the microlenses 26 focus more and more on the edge or on outer regions of the microholes 36.

If the viewer tilts the security element to the left, then the region in which the microholes 36 are viewed at the respective introduction angle continuously shifts until, at a tilt of 40°, the right side of the maple leaf appears very bright, since the viewer now has the microholes 36 introduced there at Θ = 40° in the focus of the microlenses 26. Toward the left edge of the maple leaf 16, the brightness continuously decreases since, with decreasing angle Θ, the microlenses 26 now focus more and more on the edge or on outer regions of the microholes 36. A further exemplary embodiment of the present invention is illustrated schematically in fig. 7, in cross-section, and with its visual appearance in reflected light and transmitted light in fig. 8. In the security element 50, the cover layer 28 exhibits, in addition to the gaps 30 already described and produced by the action of laser radiation, blank regions 52 that extend across a plurality of microlenses, but that are not in register with directly opposing microholes 36. Said blank regions 52 can be produced, for example, through a demetalization with a washing process before the laser impingement to produce the gaps 30. In such a washing process, before the metalization, a soluble washable ink is preferably imprinted on the support 20 in the shape of the desired demetalization region, and after the metalization, the washable ink washed off together therewith by a solvent. Further details on such a washing process can be found in document WO 99/13157, the disclosure of which is incorporated in the present application by reference.

In the exemplary embodiment shown, the gap region 52 occupies the lower half of the security element 50, as shown in fig. 8(a). In principle, however, the blank regions 52 can be developed in the form of arbitrary patterns, characters or codes.

The gaps 30 now form a first motif that, in the exemplary embodiment shown, is given by the upper half of the numerical string "10" (fig. 8(a)). In the gap region 52, through laser impingement, a plurality 54 of micro holes 56 was likewise produced that form a second motif that is presently formed precisely by the lower half of the numerical string "10." Since, in the gap region 52, a greater portion of the laser energy reaches the recording layer 32, the microholes 56 can exhibit a somewhat larger diameter than the microholes 36. To avoid said variation, the laser energy in the gap region 52 can be suitably reduced.

Figure 8 shows the visual appearance of the security element 50 produced in this way, when viewed from the side of the first main surface 22.

In reflected light, outside the gaps 30 and the gap region 52, the silvery-shining aluminum-cover layer 28 determines the appearance. In the region of the gaps 30 and in the gap region 52, the cover layer 28 is removed and the viewer sees the copper color of the recording layer 32. As in fig. 4, due to their small size, in reflected light, the microholes 36 are perceptible with the naked eye only with difficulty or not at all, such that the recording layer 32 appears as a through metal layer. The viewer thus sees, in reflected light, only the upper half of the numerical string "10," as shown in fig. 8(a). The incomplete motif depiction attracts attention and prompts the viewer to view it in transmitted light in order to see the complete motif "10."

When viewed in transmitted light, both the first motif of the gaps 30 and the second motif 54 then appear to be viewing-direction-dependently semitransparent due to the microholes 36 or 56 included, as explained in connection with fig. 4(b). Outside of said regions, in contrast, the security element 50 is intransparent, since the viewer either looks at the opaque cover layer 28 or the likewise opaque recording layer 32. The color difference between the copper-colored recording layer 32 and the silver-colored cover layer 28 strongly recedes into the background in transmitted light, and is normally only hardly perceptible or not at all. For the viewer, the first motif 30 and the second motif 54 thus complement each other to form a brightly shining complete motif in the form of the numerical string "10" against a uniformly dark background, as illustrated in fig. 8(b).

When the security element 50 is viewed from the second main surface 24 (back), the appearance already described in connection with fig. 5 results. In reflected light, from the back, only the copper-colored recording layer 32 is visible, when viewed in transmitted light, the viewer sees the whole numerical string "10" laterally reversed against the dark background of the opaque recording layer 32.

Instead of in the cover layer 28, blank regions 62 can also be provided in the recording layer 32, as illustrated by reference to figures 9 and 10, which show, schematically, a security element 60 according to the present invention, in cross-section, and the visual appearance when viewed from the front and back in reflected light and transmitted light.

In the security element 60, the recording layer 32 has, in addition to the microholes 36 already described and produced by the action of laser radiation, blank regions 62 whose dimensions are larger than the dimension of the microlenses 26 and that are not in register with directly opposing gaps 30. Said blank regions 62 can be produced, for example, through a demetalization with a washing process before the laser impingement to produce the microholes 36. In the exemplary embodiment shown, the gap region 62 occupies the lower half of the security element 60, as shown in fig. 10(a). In the upper half 64 of the security element 60, in contrast, a recording layer 32 is present. In principle, the blank regions 62 can be developed in the form of arbitrary patterns, characters or codes.

After the production of the blank regions 62 in the recording layer 32, the security element 60 was, as described above, impinged on with laser radiation to produce, simultaneously and in perfect register, gaps 30 in the cover layer 28 and microholes 36 in the recording layer 32. No additional microholes 36 can be produced in the blank regions 62.

That fractional region 74 of the gaps 30 that lies over the recording layer 32 now forms a first motif, which is given by the upper half of the numerical string "10." That fractional region 72 of the gaps 30 that lies over the gap region 62 forms a second motif, which, presently, is formed by the lower half of the numerical string "10" (fig. 10(a)).

Figure 10 shows the visual appearance of the security element 60 produced in this way. When the front is viewed in reflected light (fig. 10(a)), outside the gaps 30, the silvery-shining aluminum cover layer 28 determines the appearance. In the first fractional region 74 of the gaps 30, the cover layer 28 is removed and the viewer sees there the copper color of the recording layer 32. In the second fractional region 72 of the gaps 30, both the cover layer 28 and the recording layer 32 are removed, and the viewer sees there the background situated under the security element 60.

When the front is viewed in transmitted light (fig. 10(b)), due to the microholes 36 included, the first fractional region 74 of the gaps 30 then appears, as already described above, viewing-direction-dependently semitransparent. The second fractional region 72 of the gaps 30 appears transparent, since no recording layer 32 is present there.

When the back is viewed in reflected light (fig. 10(c)), in the upper half 64, only the copper-colored recording layer 32 is visible, the viewer sees the silver-colored cover layer 28 in the blank regions 62 and the background situated under the security element 60 in the fractional region 72 of the gaps 30.

When the back is viewed in transmitted light (fig. 10(d)), due to the plurality of microholes 36 in the recording layer 32, the security element 60 appears semitransparent in a large angular range in the upper half 64 in the fractional region 74 of the gaps. The second fractional region 72 of the gaps 30 appears transparent, since no recording layer 32 is present there.

If, instead of the copper-colored recording layer 32 in fig. 10, a silver-colored aluminum layer is chosen as the recording layer 82, then the cover layer 28 and the recording layer 82 nearly match in color. When viewed from the front in reflected light, the first fractional regions 74 of the gaps 30 in which the recording layer 82 is visible then cannot be distinguished from the surrounding cover layer 28, as shown in fig. 11(a). The viewer thus perceives only the lower half of the complete motif. In transmitted light, the first motif of the first fractional regions 74 is then complemented by the second motif of the second fractional regions 72 to form the whole numerical string "10," as shown in fig. 11(b).

Also when viewed from the back, the recording layer 82 and the cover layer 28 lying outside the fractional regions 72 of the gaps 30 appear, in reflected light, having the same color, as depicted in fig. 11(c). The viewer thus perceives, also from the back, only the lower half of the complete motif. In transmitted light, the first motif of the first fractional regions 74 is then complemented by the second motif of the second fractional regions 72 to form the complete numerical string "10," as shown in fig. 11(d).

The described effects can be combined with a micro-optical display arrangement, especially a moire magnification arrangement, a moire-type micro-optical magnification arrangement or a modulo magnification arrangement, as illustrated in the exemplary embodiment in fig. 12.

For this, the recording layer 92 of the security element 90 includes, in addition to the microholes 36 already described, a grid-shaped arrangement of micromotif elements 94. The arrangement of the micromotif elements 94 forms, like the arrangement of the microlenses 26, a lattice having a prechosen symmetry, a desired moire-magnification effect and characteristic motion effects being produced by the coordination of the microlens lattice and the lattice of the micromotif elements 94. Here, in the case of a moire magnification arrangement, the Bravais lattice of the lattice cells of the micromotif elements 94 differs slightly in its orientation and/or in the size of its lattice parameters from the Bravais lattice of the microlenses 26, as indicated in fig. 12 by the offset of the micromotif elements 94 with respect to the microlenses 26. When the motif image is viewed, a moire-magnified image of the micromotif elements 94 is created according to the type and size of the offset. Such security elements having micro-optical display arrangements also facilitate impressive motion effects, as explained in greater detail in the above-mentioned document. For example, the lattice parameters of the arrangement of the imaged regions and of the microlens grid can be coordinated with each other in such a way that, when the security element 90 is tilted, an orthoparallactic motion effect results in which the depicted motif moves vertically to the tilt direction and not parallel thereto, as one would intuitively expect.

Within the scope of the present invention, said moire effects are visible only in the region of the gaps 30 or of blank regions 52 of the cover layer 28. If the same material or materials of the same color are chosen for the cover layer 28 and the recording layer 92, then, in reflected light, nearly only the moire effects are visible in the regions 30, 52.

In the embodiments described thus far, the laser-sensitive cover layer and the laser-sensitive recording layer were, for illustration, each formed by opaque metal layers. However, both the cover layer and the recording layer can, for example, also be formed by a thin-film element having a color-shift effect, as specified above.

The cover layer and/or the recording layer can also be developed to be semitransparent and, here, especially exhibit a transmittance between 20% and 90%. If the cover layer 28 is semitransparent, then the moire effect in fig. 12 can, for example, also be visible outside the gaps 30, with reduced brightness. If both the cover layer 28 and the recording layer 32 are semitransparent, then the security element exhibits a certain residual transparency also outside the gaps and blank regions. This can be advantageous especially when the security element, as in fig. 1, is arranged over an opening 14 or a window region of a value document. The shape and contour of the opening 14 are then perceptible in transmitted light.

In further embodiments, the cover layer 28 can also be formed by a laser-sensitive transparent coating 100, as illustrated in fig. 13. The coating 100 can be, for example, an IR lacquer that is largely transparent in the visible spectral range, but strongly absorbs the radiation of an infrared laser used for impingement, for example the 1.064 pm radiation of a NdiYVQ* laser.

The optical effectiveness of the microlenses 26 can also be reduced by such a transparent coating in that the radius of curvature of the lenses is changed, for example by 50% or more. In particular, the transparent layer can level the lenses and completely annul the optical effect. Here, the refractive index of the transparent coating 100 is expediently on the order of the refractive index of the microlenses 26.

Between the levelling laser-sensitive coating 100 and the microlenses 26, optionally, a further thin layer 102 can be provided. This can be, for example, a coating that promotes the removal of the laser-sensitive coating 100. The further thin layer 102 can also be a reflective layer, for example an aluminum layer, such that, outside the demetalized regions, the microlenses 26 act as concave microreflectors. In this way, the presently described effects can be combined with the effects of magnification arrangements on both sides, which are described in greater detail in document WO 2010/136339 A2. The disclosure of WO 2010/136339 A2 is incorporated in the present application by reference.

With reference to the depiction in fig. 14, instead of circular microholes, also patternshaped microholes 110 can be produced in the laser impingement. For this, the angle of incidence of the laser radiation 40,40' upon laser impingement is varied in accordance with the desired shape of the pattern-shaped microhole 110. For example, through a simple tilting of the laser radiation 40,40'in one spatial direction upon impingement, a demetalized line 110 can be produced in the recording layer 32.

Here, the shape of the gap 30 does not change.

Through a variation of the angle of incidence of the laser radiation 40 in two spatial directions, also microholes in the form of two-dimensional patterns 112 can be produced, as shown in the top view of the recording layer 32 in fig. 15(a). The shape of the gap 30 does not change here, either, since, at the location of the cover layer 28, only the angle of incidence varies, not the position of the laser beam 40.

Instead of microholes, also other micromarkings 114 can be produced in the recording layer 32, as illustrated in fig. 15(b). For example, the color of the recording layer 32 can change due to the action of the laser radiation focused by the microlenses 26. In this way, by varying the angle of incidence of the laser radiation 40 in two spatial directions, within a recording layer 32 having a first color, micromarkings 114 having a second color can be produced. Thus, for the laser-sensitive recording layer 32, in addition to the metal layers already mentioned, also other laser-sensitive materials whose visual appearance permits changing by the action of laser radiation may be considered.

In all designs mentioned, the gaps 30 and the plurality of micromarkings can include an individualization of the security element, for example the serial number of a banknote 10. Such registered individualizations can be reproduced with other methods only with great difficulty and thus exhibit high counderfeit security.

The individualization of the security element can especially be combined with the tilt images described in connection with fig. 6. For example, the micromarkings introduced at a vertical angle can constitute a non-individualizing graphic motif. At an oblique angle are then introduced into the recording layer micromarkings that constitute an individualization, for example the signature of the owner of an identity card, or a serial number. When the security element is tilted, the visible depiction then changes from the graphic motif when viewed vertically to the individualization when viewed obliquely. A further exemplary embodiment of the present invention is illustrated schematically in fig. 16, in cross-section, and with its visual appearance in reflected light and transmitted light in fig. 17. In the security element 120, the cover layer 28 exhibits, in addition to the gaps 30 already described, congruent blank regions 122,124 produced by the action of laser radiation in the cover layer 28 or in the recording layer 32. To produce the blank regions 122,124, the laser energy was increased so much that not only the cover layer 28, but also the recording layer 32 below the microlenses 26 was completely ablated. The gaps 30 and the microholes 36, in contrast, are produced at lower laser energy, at which the residual energy after the ablation of the cover layer 28 leads only to the production of the small microholes 26 in the recording layer 32.

Since it is possible to increase the laser energy and lower it again nearly without time delay, the blank regions 122 and the gaps 30 can connect to each other seamlessly and in perfect register. In the exemplary embodiment shown, the gaps 30 form a first motif that is given by a portion of the numerical string "50," which is indicated in fig. 17(a) by the dotted contour. The blank regions 122 form a second motif that is given by the remainder of the numerical string "50."

Figure 17 shows the visual appearance of the security element 120 produced in this way, when viewed from the side of the first main surface 22. To ensure matching color, here, the cover layer 28 and the recording layer 32 consist of the same material, for example aluminum. With reference to fig. 17(a), in reflected light, only the second motif of the blank regions 122,124 is perceptible for the viewer, since the background situated under the security element 120 shows through there. In the gaps 30 in the cover layer 28, in contrast, the viewer looks at the recording layer 32 of matching color, such that the gaps 30 do not appear in reflected light due to the lack of contrast and due to the smallness of the microholes 36. The incomplete motif depiction thus prompts the viewer to view it in transmitted light to be able to perceive the whole motif.

When viewed in transmitted light, the first motif of the gaps 30 then appears, as shown in fig. 17(b), viewing-direction-dependently semitransparent, as already explained multiple times above. The first and second motif thus complement each other to form a brightly shining complete motif in the form of the numerical string "50" against a uniformly dark background. When viewed from the back of the security element 120, the same motif completion results, albeit with a laterally reversed complete motif.

Figure 18 shows a security element 130 according to a further exemplary embodiment of the present invention, in which is arranged, on a recording layer 32 of copper, a reflection layer 132 of aluminum that includes no microholes. Here, the microholes 134 in the recording layer 32 are somewhat larger than explained in the above-described exemplary embodiments, and have, at a 30 pm diameter of the microlenses, a diameter of 5 - 15 pm. The security element 130 displays, when viewed in reflected light, a tilt image. From the viewing angle from which the microholes 134 were introduced, the viewer looks through the microholes 134 at the silver-colored reflection layer 132 and thus sees the motif formed by the microholes 134 as silver-colored against the copper-colored background of the recording layer 32. If the viewer tilts the security element 130 to another viewing angle, then only the copper-colored recording layer 32 is visible and the motif disappears. The layer 132 can also be, for example, a print layer applied to the underlying substrate, for instance a banknote paper.

The term "comprise" and variants of that term such as "comprises" or "comprising" are used herein to denote the inclusion of a stated integer or integers but not to exclude any other integer or any other integers, unless in the context or usage an exclusive interpretation of the term is required.

The term 'vertical' and 'vertically7 as used herein in relation to the security element are used in the context that the described security element is shown in a horizontal orientation. It will be apparent to a person skilled in the art that these terms 'vertical' and 'vertically' are intended to mean 'perpendicular' and 'perpendicularly' to the plane of the support 20 of the security element, and the interpretation of 'vertical' and 'vertically' will vary according to the orientation of the security element.

Reference to background art or other prior art in this specification is not an admission that such background art or other prior art is common general knowledge in Australia or elsewhere.

List of reference signs 10 Banknote 12 Security element 14 Opening 16 Fractional regions 20 Support 22, 24 Main surfaces 26 Microlenses 28 Cover layer 30,30' Gap 32 Recording layer 34 Plurality of microholes 36,36' Microholes 40, 40' Laser radiation 42 Focused laser radiation 44 Vertical 50 Security element 52 Blank regions 54 Plurality of microholes 56 Microholes 60 Security element 62 Blank regions 64 Upper half of the security element 72, 74 Fractional regions 82 Recording layer 90 Security element 92 Recording layer 94 Micromotif elements 100 Transparent coating 102 Thin layer 110,112,114 Pattern-shaped microholes 120 Security element 122,124 Blank regions 130 Security element 132 Reflection layer 134 Microholes

Claims (26)

1. Claims

   1. An optically variable security element for security papers, value documents and other data carriers, the optically variable security element having a substantially transparent support having opposing first and second main surfaces, an arrangement of micro lenses arranged on the first main surface of the support, and a laser-sensitive recording layer arranged on the second main surface of the support, characterized in that the microlens arrangement is provided with a laser-sensitive cover layer that has at least one gap that is produced by the action of laser radiation and that extends across multiple microlenses, the laser-sensitive recording layer has a plurality of micromarkings produced by the action of laser radiation, each micromarking being associated with a respective microlens and being visible when the security element is viewed through the associated microlens, and the plurality of micromarkings are arranged on the support in perfect register directly opposite the at least one gap.
2. 2. The security element according to claim 1, characterized in that the micromarkings are formed by microholes in the recording layer, especially by substantially circular microholes or by pattern-shaped microholes.
3. 3. The security element according to claim 1 or 2, characterized in that the micromarkings are each smaller than their respective associated microlenses.
4. 4. The security element according to any one of claims 1 to 3, characterized in that the ratio of the area of a micromarking to the area of its respective associated microlens lies below 1.0 or preferably below 0.5 or even more preferably below 0.2.
5. 5. The security element according to any one of claims 1 to 4, characterized in that the security element is semitransparent in the region of the at least one gap and the opposing micromarkings.
6. 6. The security element according to any one of claims 1 to 5, characterized in that the micromarkings are introduced into the recording layer through the microlens arrangement from at least two different directions with laser radiation, and are perceptible when viewed from each of said at least two different directions.
7. 7. The security element according to any one of claims 1 to 6, characterized in that the direction in which the micromarkings are introduced into the recording layer through the microlens arrangement with laser radiation varies continuously across the dimension of the gap, such that the degree of transparency when viewed in transmitted light changes continuously with the viewing direction.
8. 8. The security element according to any one of claims 1 to 7, characterized in that the cover layer has, in addition to the at least one gap produced by the action of laser radiation, blank regions that extend across multiple microlenses and that are not in register with directly opposing micromarkings.
9. 9. The security element according to claim 8, characterized in that the at least one gap form(s) a first motif in the form of patterns, characters or a code, in the blank regions of the cover layer, further micromarkings produced by the action of laser radiation are present in the recording layer that form a second motif in the form of patterns, characters or a code, and in that when viewed in reflected light, only the first motif is perceptible, and when viewed in transmitted light, the first and second motif are perceptible, and the two motifs complement each other to form a complete motif.
10. 10. The security element according to any one of claims 1 to 9, characterized in that the recording layer has, in addition to the micromarkings produced by the action of laser radiation, blank regions whose dimensions are larger than the dimension of the microlenses and that are not in register with directly opposing gaps, and especially in that those fractional regions of the gap(s) that lie over the micromarkings of the recording layer form a first motif in the form of patterns, characters or a code, those fractional regions of the gap(s) that lie over blank regions of the recording layer form a second motif in the form of patterns, characters or a code, and in that when viewed in transmitted light, the first and second motifs are perceptible and the two motifs complement each other to form a complete motif.
11. 11. The security element according to claim 8, characterized in that, directly opposite the blank regions of the cover layer, congruent blank regions are present in the recording layer, and especially in that the at least one gap form(s) a first motif in the form of patterns, characters or a code, the blank regions of the cover layer form a second motif in the form of patterns, characters or a code, and in that when viewed in reflected light, only the second motif is perceptible, and when viewed in transmitted light, the first and second motif are perceptible, and the two motifs complement each other to form a complete motif.
12. 12. The security element according to any one of claims 1 to 11, characterized in that the security element includes a micro-optical display arrangement, especially a moire magnification arrangement, a moire-type micro-optical magnification arrangement or a modulo magnification arrangement.
13. 13. The security element according to any one of claims 1 to 12, characterized in that the recording layer and/or the cover layer are/is opaque, especially in that the recording layer and the cover layer are formed by an opaque metal layer or include an opaque metal layer.
14. 14. The security element according to any one of claims 1 to 13, characterized in that the recording layer and/ or the cover layer are/is semitransparent, each preferably having a transmittance between 20% and 90%.
15. 15. The security element according to any one of claims 1 to 14, characterized in that the cover layer and/ or the recording layer are/is formed by a thin-film element having a color-shift effect, and/or in that the cover layer and/or the recording layer are/is formed by a laser-sensitive ink layer.
16. 16. The security element according to any one of claims 1 to 15, characterized in that the cover layer and the recording layer match in color, especially in that the cover layer and the recording layer consist of the same material, especially of the same metal.
17. 17. The security element according to any one of claims 1 to 12, characterized in that the cover layer is a transparent layer that changes the radius of curvature of the microlenses by at least 50%, especially a transparent layer that levels the microlenses, and especially in that the refractive index of the transparent cover layer differs by 0.3 or less from the refractive index of the microlenses.
18. 18. The security element according to any one of claims 1 to 17, characterized in that the micromarkings are formed by microholes in the recording layer and in that a reflection layer or a print layer is arranged on the recording layer, and especially in that the reflection layer or the print layer has no microholes.
19. 19. A data carrier having a security element according to any one of claims 1 to 18.
20. 20. The data carrier according to claim 19, characterized in that the security element is arranged in or over a window region or a through opening in the data carrier, or in that the data carrier includes a data carrier substrate that has a marking region that is produced by the action of laser radiation and that adjoins at least one of the gaps produced in the security element by laser radiation and is in register therewith, and especially in that in the marking region, by the action of laser radiation, color components or metallic substances are removed from the data carrier substrate, or the data carrier substrate is foamed.
21. 21. A method for manufacturing an optically variable security element for security papers, value documents and other data carriers, comprising providing a substantially transparent support having opposing first and second main surfaces, with an arrangement of microlenses being arranged on the first main surface of the support, providing a laser-sensitive recording layer on the second main surface of the support, providing the microlens arrangement with a laser-sensitive cover layer, producing in the laser-sensitive cover layer, by the action of laser radiation, at least one gap that extends across multiple microlenses, producing a plurality of micromarkings in the laser-sensitive recording layer by the action of laser radiation, each micromarking being associated with a respective microlens and being visible through the associated microlens when the security element is viewed, and arranging the plurality of micromarkings on the support in perfect register directly opposite the at least one gap.
22. 22. The method according to claim 21, characterized in that the at least one gap in the laser-sensitive cover layer and the opposing micromarkings in the laser-sensitive recording layer are produced in the same operation by the same laser beam, and/or that the micromarkings are produced in the recording layer through the microlens arrangement from at least two different directions.
23. 23. A method for manufacturing the data carrier according to claim 20, comprising providing a data carrier substrate, providing a substantially transparent support having opposing first and second main surfaces, with an arrangement of microlenses being arranged on the first main surface of the support, arranging a laser-sensitive recording layer on the second main surface of the support, providing the microlens arrangement with a laser-sensitive cover layer, applying the support having the laser-sensitive recording layer, the microlens arrangement and the laser-sensitive cover layer to the data carrier substrate, and in the same operation, by the same laser beam, by the action of laser radiation, a) producing at least one gap in the laser-sensitive cover layer that extends across multiple microlenses, b) producing a plurality of micromarkings in the laser-sensitive recording layer, each micromarking being associated with a respective microlens and being visible when the security element is viewed through the associated microlens, the plurality of micromarkings being arranged on the support in perfect register directly opposite the at least one gap, and c) in the data carrier substrate outside the region in which the support having the recording layer, the microlens arrangement and the cover layer is applied to the data carrier substrate, producing a marking region that adjoins the cover layer at at least one of the gaps.
24. 24. The method according to claim 23, characterized in that, in the marking region, by the action of laser radiation, color components or metallic substances are removed from the data carrier substrate, or the data carrier substrate is foamed.
25. 25. An optically variable security element for security papers, value documents and other data carriers, the optically variable security element having a substantially transparent support member having opposing first and second main surfaces, an arrangement of microlenses arranged on the first main surface of the support, a laser-sensitive cover layer disposed over the arrangement of microlenses, the laser-sensitive cover layer having at least one gap that is produced by laser radiation and that extends across multiple microlenses, and a laser-sensitive recording layer arranged on the second main surface of the support, the laser-sensitive recording layer having a plurality of micromarkings produced by laser radiation, each micromarking being associated with a respective microlens, such that when the security element is viewed, each micromarking is visible through its associated microlens, and wherein the plurality of micromarkings are located directly opposite the at least one gap and exclusively occupy an area which is congruent with the at least one gap.
26. 26. An optically variable security element as claimed in claim 25, wherein each micromarking is formed by laser radiation through its associated microlens.