CA2774819C - Data carrier having a window - Google Patents

Abstract

The present invention relates to a data carrier, especially a value or security document, having a window (14) that extends from a bottom (16) to a top (18) of the data carrier and a foil element (20) having a security element (22) that covers the window (14) on the top (18) of the data carrier, a portion of the security element (22) lying over the window (14) and a portion of the security element (22) next to the window (14). Here, according to the present invention, it is provided that the portion of the security element (22) that lies over the window (14) exhibits a radiation modification region (24) that is in register with the window (14) and in which the visual appearance of the security element (22) is modified by the action of electromagnetic radiation.

Description

Data Carrier Having a Window The present invention relates to a data carrier, especially a value or security document, having a window that extends from a bottom to a top of the data carrier, and having a foil element having a security element that covers the window on the top of the data carrier, a portion of the security element lying over the window and a portion of the security element next to the window.
For protection, security or value documents, such as banknotes, identification cards and the like, are often furnished with security elements that permit the authenticity of the documents to be verified, and that simultaneously serve as protection against unauthorized reproduction. Here, see-through security features, such as see-through windows in banknotes, are increasingly becoming more attractive. For window production, here, a foil provided with an adhesive layer on one side, for example, is applied to a banknote to close a previously produced through opening in the banknote.
Here, the application of the foil to the banknote is subject to unavoidable registration tolerances, such that a security element of the foil that is specially coordinated with an opening cannot be perfectly aligned with the opening. Said registration tolerances must be taken into account in the design of the security element, which limits the liberties in the creation of the designs.
Proceeding from this, the object of the present invention is to further develop a data carrier of the kind cited above and especially to facilitate applied security elements having designs that are highly precisely registered with

- 2 -the window and, in this way, to combine an attractive visual appearance with high counterfeit security.
This object is solved by the data carrier having the features of the main claim.
A method for manufacturing such a data carrier is specified in the coordinated claim. Developments of the present invention are the subject of the dependent claims.
According to the present invention, in a generic data carrier, it is provided that the portion of the security element that lies over the window exhibits a radiation modification region that is in register with the window and in which the visual appearance of the security element is modified by the action of electromagnetic radiation.
Here, the present invention is based on the idea of permitting registration tolerances between the security element of the foil element to be applied and the window of the data carrier, but to modify, through the action of radiation, especially through laser impingement, the visual appearance of the security element in a modification region that is in register with the window. The register variations between the foil element and the window then largely or completely recede into the background when viewed and, instead, the perfect register between the window and the modification region dominates the optical impression for the viewer.
Due to the exact alignment of window and modification region with each other, said two elements can also be coordinated with or related to each other in their visual appearance and/or their information content. For example, the window and the modification region can depict the same motif,

- 3 -or can each depict only motif portions that complement each other to form a complete motif. Such a visual or content-related interaction, on the one hand, increases the attention and recognition value of the protection and, on the other hand, results in increased counterfeit security, since the manufacture of the security features window and modification region that are linked in terms of content constitutes a higher technological barrier than the manufacture, separately or unlinked in terms of content, of two security features.
The window of the data carrier can be formed by a through opening that extends from the bottom to the top of the data carrier. The window can also be formed by a transparent region of the data carrier that allows a visual through view, such as an unprinted region of a polymer banknote. In multi-ply data carriers, a window can also be formed by a combination of transparent regions in first data carrier plies and through openings in second data carrier plies, for example the paper ply, and a not completely transparent ink absorption layer of a composite banknote.
In an advantageous variant of the present invention, the security element exhibits a metal layer that is demetalized in the radiation modification region. Here, demetalization is understood to be the ablation of the metal layer or its transformation into a transparent modification. The metal layer can be completely demetalized, in other words completely removed or completely transformed into a transparent modification, or it can also be only partially demetalized to create a modification region that is still semitransparent, especially having a transmittance between 20% and 80%.
As explained in greater detail below, in the region of the opening, the metal layer can also be demetalized only in some regions such that the radiation

- 4 -modification region inside the area of the opening produces a sub-pattern that is perfectly registered with the opening.
The security element especially includes a metalized diffraction pattern, a metalized blazed diffraction pattern, a metalized matte pattern or a thin-film element having a color-shift effect that is typically formed from a metallic reflection layer, a dielectric spacing layer and an absorber layer. In addition, also other security elements having metalized structures, such as metalized concave microreflectors, may be considered.
In an advantageous variant of the present invention, the security element exhibits first and second fractional regions that interact differently with the electromagnetic radiation, both first and second fractional regions lying partially over the window and partially next to the window. Here, the different interaction can lie in a different extent or also in a different kind of interaction.
For example, a different extent of the interaction in metalized security elements can lead to a demetalization of only the first fractional region or, in radiation-colorable or radiation-bleachable security elements, to a color change of only the first fractional region or also to an intense color change of the first fractional region. In interactions of different extents, both fractional regions react fundamentally in the same manner, but one fractional region to a greater extent than the other, which reacts to a lesser extent or even not at all.
With different types of interaction, in contrast, both fractional regions react to the action of radiation, but in different manners. For example, a colorless

- 5 -region of a radiation-colorable security element can turn red in the first fractional region and blue in the second fractional region. Also in this way, a different visual appearance can be achieved in the modification region.
In an advantageous embodiment, the radiation modification region comprises only first, but not second fractional regions, such that the second fractional regions display the same visual appearance over and next to the window.
To achieve a different interaction extent, in a preferred embodiment, at least one of the two fractional regions exhibits an interference pattern, preferably a relief pattern in the form of a grating pattern that is defined by a grating constant and an orientation of the grating lines. The second fractional region can include no relief pattern or likewise a relief pattern in the form of a grating pattern that is defined by a second grating constant and a second orientation of the grating lines, the second grating constant and/or the second orientation of the grating lines of the second fractional region differing from the first grating constant or the first orientation of the grating lines of the first fractional region. The grating pattern of the second fractional region can also exhibit the same grating constant and orientation of the grating lines as the grating pattern of the first fractional region, but be tilted by a certain angle against the first grating pattern, for example in that the grating patterns are arranged on the sides of a sawtooth structure.
The material ablation occurs with the aid of the grating pattern, which exhibits an increased absorption. The increased light absorption can be explained physically by resonance excitation in the metal (surface plasmon polaritons or cavity resonances). For this, the grating constant is expediently

- 6 -chosen such that it is on the order of magnitude of the wavelength of the laser light used for the radiation modification. The resonant light absorption at the grating further depends very strongly on the profile cross section and on the grating material, as well as on the surrounding material. The profile is thus expediently adapted for the laser wavelength used in order to achieve a high absorption. For example, a grating having laterally different trench depths displays a laterally different absorption performance. In an advantageous embodiment, the first fractional region includes a grating pattern having as high absorption as possible, and the second fractional region is developed without a grating pattern. The incident laser radiation then leads, for a coordinated wavelength, angle of incidence and polarization, to the demetalization of the grating region.
In particular, the second orientation of the grating lines can be substantially perpendicular to the first orientation to achieve different interactions of the fractional regions with linearly polarized electromagnetic radiation. In a preferred embodiment, the two fractional regions exhibit a grating pattern having a grating constant of 750 to 1,050 nm, preferably of about 900 nm, and having different orientations of the grating lines.
A further possibility to produce a different interaction for two fractional regions filled with grating patterns consists in the use of grating patterns having different grating profiles for the first and second fractional region.
Particularly preferred are variants of the present invention in which the two fractional regions interact to different extents with polarized laser radiation, since, here, a clear difference in the extent of the interaction can be achieved easily. In a development of the present invention, it is provided that the two fractional regions are formed from nested sub-regions. The sub-regions can

- 7 -especially consist of parallel strips, preferably having a strip width between pm and 500 p.m.
In a further embodiment having differently interacting fractional regions, the 5 first fractional region includes a surface-enlarging relief pattern, preferably a surface-enlarging relief pattern having an intersecting sinusoidal surface topography. The surface topography can exhibit, for example, a height of 200 to 400 nm, preferably of about 300 nm, and in the x- and y-direction, a grating constant of 200 to 400 nm each, preferably of about 300 nm.
Further details on the selective removal of only one of two or more fractional regions by radiation impingement are specified in publication WO 2006/079489 Al.
In a further possibility for producing differently interacting fractional regions, the first and second fractional regions are formed by elevations and depressions of an embossing pattern. In particular, for this, - a support is provided with an embossing pattern having elevations and depressions that form first and second regions having different first and second level heights, the second regions of the embossing pattern being developed in the form of a desired pattern, - the embossing pattern is contiguously metalized with the first and second regions, and - the metalized embossing pattern is impinged on with radiation to selectively remove the metalization in the second regions of the embossing pattern by the action of the radiation.

- 8 -The radiation impingement can especially occur with laser radiation.
Here, after the metalization step, a laser beam absorbing and/or a laser beam reflecting cover layer that fills the depressions of the embossing pattern is preferably applied to the metalized embossing pattern. In the selection of the cover layer, it is of primary importance that less laser radiation is transmitted in the region of the depressions. A laser beam reflecting cover layer can thus display the same or even a better effect than a laser beam absorbing cover layer. After its application, the cover layer is removed, especially squeegeed off or wiped off, from the elevated regions of the metalized embossing pattern. Here, a technically unavoidable, thin toning film of the cover layer can remain on the elevated regions of the metalized embossing pattern. Such a cover layer advantageously includes laser beam absorbing or laser beam reflecting pigments or dyes and can, in this case, additionally be used as the ink layer to create the design that is visible from the bottom as desired.
Further details and variants of the patterning method on the basis of a metalized embossing pattern having elevations and depressions are described in publication number WO 2009/100869 A2.
The present invention can be used particularly advantageously in microoptical depiction arrangements, such as microoptical moire magnification arrangements, microoptical moire-type magnification arrangements and the more general modulo magnification arrangements that are described especially in the international applications WO 2009/00528 Al and WO 2006/087138 Al. All these microoptical magnification arrangements include a motif image that has micropatterns

- 9 -and that, when viewed with a suitably coordinated viewing grid, reconstructs a specified target image.
As explained in greater detail in the above-mentioned publications and applications, here, it is possible to produce a number of visually attractive magnification and movement effects that result in a high recognition value and high counterfeit security of the security elements produced. For example, the grating parameters of the motif image and of the viewing grid can be coordinated with each other in such a way that, when the depiction arrangement is tilted, an orthoparallactic movement effect results in which the first motif moves perpendicular to the tilt direction and not parallel thereto, as one would intuitively expect.
Here, in a variant of the present invention, it can be provided that the security element includes micropatterns having a line width between about 1 m and about 10 pm, whose visual appearance is modified in the radiation modification region. Here, the micropatterns advantageously form, at least inside or at least outside the radiation modification region, a motif image that is subdivided into a plurality of cells, in each of which are arranged imaged regions of a specified target image. Here, the lateral dimensions of the imaged regions are preferably between about 5 pm and about 50 pm, especially between about 10 !Am and about 35 pm.
Moreover, a viewing grid composed of a plurality of viewing grid elements is preferably provided for reconstructing the specified target image when the motif image is viewed with the aid of the viewing grid, the lateral dimensions of the viewing grid elements advantageously being between

- 10 -about 5 gm and about 50 gm, especially between about 10 gm and about 35 gm.
The modification in the radiation modification region can consist, for example, in a selective demetalization of a metal layer that makes the micropatterns of a motif image perceptible. In another variant, the micropatterns are colored, the color of the micropatterns being modified in the radiation modification region. Here, through the action of radiation, especially a first color can be transformed into a second color. One of the two colors can also be transparent, in particular, a first color can be bleached by the action of radiation and thus be made transparent, or transparent regions can be dyed through the action of radiation and thus made colored.
In advantageous embodiments, the micropatterns inside and outside the radiation modification region each depict a different motif, especially different patterns, characters or codes. The change between the different patterns, characters or codes then occurs aligned in perfect register with the cut edges of the window.
For this, the micropatterns advantageously lie in a two-layer lacquer system having two stacked lacquer layers having substantially the same refractive index. Here, a second motif image is embossed in the lower lacquer layer and a first motif image in the upper lacquer layer arranged over the lower lacquer layer. In the radiation modification region, the upper lacquer layer is removed such that, there, the second motif of the lower lacquer layer and, outside the radiation modification region, the first motif of the upper lacquer layer is visually perceptible.

- 11 -In a further variant of the present invention is provided that - the security element comprises multiple reflective first micro-imaging elements arranged areally in a viewing element pattern, and transmissive second micro-imaging elements arranged areally in the viewing element pattern, - the second micro-imaging elements lying inside and the first micro-imaging elements outside the radiation modification region, - the security element further comprising a micropattern object that includes multiple micropatterns that are arranged in a microstructure pattern that is coordinated with the viewing element pattern in such a way that, by means of the first micro-imaging elements, the micropattern object is imaged magnified in front of the top, and - an object plane region that lies outside the security element being allocated to the second micro-imaging elements such that the micropatterns of the micropattern object are not perceptible when viewed from the bottom by means of the second micro-imaging elements, but for verification, a further micropattern object having multiple micropatterns is positionable in the object plane region such that, by means of the second micro-imaging elements, the further micropattern object is imaged magnified in front of the bottom.
Here, in particular, the first micro-imaging elements are developed as concave microreflectors and/or the second micro-imaging elements as microlenses. Further details and advantages of such a combination of microlenses and concave microreflectors can be found in German patent publication number DE 10 2009 022 612 Al.

- 12 -According to the present invention, the shape of the window is not subject to any restrictions. In all embodiments, it can especially be developed in the form of a pattern or of characters or codes. If the window is formed by a through opening or if the window comprises a through opening, then also screened openings can be used particularly advantageously as they are described in German patent application DE 10 2009 011 424 Al. If the through opening is formed by such a line grid composed of a plurality of parallel cutting lines, then the above-described register effects even stand out particularly clearly due to the large number of transitions from support to opening.
In the present description, reference is usually made to a through opening, also when, as is clear from the examples, this opening can consist of multiple parts and could also be referred to as a group of multiple openings.
Alternatively or additionally to the window, also the radiation modification region is advantageously developed in the form of a pattern or of characters or codes. The patterns, characters or codes of the radiation modification region and window are particularly advantageously identical or related to each other, for example complement one another to form a complete motif.
In a preferred development, it is provided that the foil element is applied to the top of the data carrier with a laser-ablatable adhesive layer, and the laser-ablatable adhesive layer is removed in the region of the window. In this way, a particularly clear visual appearance can be achieved in the window.

- 13 -The present invention also includes a method for manufacturing a data carrier, having the method steps:
a) providing a data carrier substrate having a window that extends from a bottom to a top of the data carrier substrate, and a foil element having a security element, b) covering the window on the top of the data carrier substrate with the foil element in such a way that a portion of the security element comes to lie over the window and a portion of the security element next to the window, and c) impinging on the security element from the bottom of the data carrier substrate and through the window with electromagnetic radiation to modify the visual appearance of the security element in a radiation modification region that lies over the window.
Here, in step c), the security element is preferably impinged on with laser radiation, especially with UV radiation, visible radiation or near-infrared radiation of a wavelength up to 1.5 pm.
In step b), the foil element is advantageously applied to the top of the data carrier with a laser-ablatable adhesive, and an adhesive that is present in the region of the window is removed in step c) by the laser impingement.
If the window is formed by a through opening, or if the window comprises a through opening, then, in step a), the through opening is introduced into the data carrier substrate or into the data carrier ply that includes the through

- 14 -opening preferably by punching or by laser cutting with a cutting laser, in the case of laser cutting, preferably with a wavelength of about 10.6 gm.
In producing the through opening, also an edge or surrounding region of the opening on the bottom of the data carrier substrate or the data carrier ply can be dyed or modified in order, through register effects, to integrate the opening on both sides of the data carrier or a data carrier ply. For this, preferably - the data carrier substrate or the data carrier ply is provided with a laser-modifiable marking substance at least in the vicinity of the through opening to be produced, - the through opening is introduced into the data carrier substrate or the data carrier ply by the action of laser radiation, and - the laser-modifiable marking substance is modified in the vicinity of the opening by the action of laser radiation.
Here, the marking substance can be modified not only in the opening edge region immediately adjoining the opening, the laser modified region can also exhibit a certain small distance from the opening. Preferably, the laser modifiable marking substance is itself modified by the cutting laser beam when producing the through opening in the data carrier substrate. Here, the fact is used to advantage that the laser energy in an outer region of the profile of the cutting laser beam is sufficient to modify, simultaneously with the laser cutting process, the marking substance arranged in the edge region or in the vicinity of the opening to be cut. In this way, a perfect registration of openings and laser modified edge region or vicinity is automatically ensured.

- 15 -Alternatively or additionally, in the same operation, through a laser module, on the one hand, the through opening can be introduced into the support with higher laser energy and, on the other hand, the laser modifiable marking substance can be modified in the vicinity of the opening with lower laser energy. Since both steps are carried out in the same operation, a highly precise registration (offset less than 0.4 mm, especially of less than 0.2 mm or even of less than 0.1 mm) of opening and laser modified vicinity is achieved.
Further details and advantages of such a method can be found in publication WO 2009/003587 Al.
The data carrier can especially be a value document, such as a banknote, especially a paper banknote, a polymer banknote or a foil composite banknote, or an identification card, such as a credit card, bank card, cash card, authorization card, a personal identity card or a passport personalization page.
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.
The different exemplary embodiments are not limited to the use in the form specifically described, but rather can also be combined with one another.
Shown are:
Fig. 1 a schematic diagram of a banknote according to an exemplary embodiment of the present invention,

- 16 -Fig. 2 a cross section through the banknote in fig. 1 along the line II-Fig. 3 in (a) to (c), the manufacturing sequence and an example of a visual and content-based interaction between opening and hologram, Fig. 4 in (a), a cross section through a security paper according to the present invention, and in each of (b) and (c), a top view of the top or bottom of the security paper in the region of the hologram or through opening, Fig. 5 intermediate steps in the manufacture of a security paper according to the present invention, (a) showing a top view of the security element to be applied and (b) a top view of the security paper before the application of the security element, and (c) and (d) showing the finished security paper in top view and in cross section, Fig. 6 in (a) and (b), intermediate steps in the manufacture of a further security paper according to the present invention, Fig. 7 a top view of a security paper according to an exemplary embodiment of the present invention, Fig. 8 a view of the bottom of a security paper according to a further exemplary embodiment of the present invention,

- 17 -Fig. 9 a microoptical depiction arrangement according to an exemplary embodiment of the present invention, in cross section, Fig. 10 a moire magnification arrangement having micromotif elements of different color impressions inside and outside the opening, Fig. 11 in (a) in cross section and in (b) in top view, a microoptical depiction arrangement according to the present invention, in which a change in the depicted motif image occurs at the cut edges of the through opening, and Fig. 12, 13 two exemplary embodiments of the present invention that are formed on the basis of a combination of microlenses and concave microreflectors.
The invention will now be explained using banknotes as an example. For this, figures 1 and 2 show, in top view and in cross section, a schematic diagram of a banknote 10 whose banknote paper 12 is provided with a window in the form of a through opening 14 that extends from the bottom 16 to the top 18 of the banknote paper 12. On the top 18 of the banknote paper 12, the through opening 14 is covered with a foil strip 20.
While the present invention is explained in the following using the example of through openings in banknotes, the present invention is not restricted to such embodiments. Rather, the window of a data carrier can also be formed

- 18 -by a transparent region of the data carrier that permits a visual through view, such as a see-through window of polymer banknotes. In multi-ply data carriers, a window can also be formed by a combination of transparent regions in first data carrier plies and through openings in second data carrier plies, for example the paper ply, and the not completely transparent ink absorption layer of a composite banknote.
The foil strip 20 in figures 1 and 2 includes a security element in the form of a metalized hologram 22 that lies partially over and partially next to the through opening 14. For this, the hologram 22 typically exhibits a larger area than the through opening 14, and the foil strip 20 is applied to the banknote paper 12 in such a way that the hologram 22 completely covers the opening 14 and also overlaps a region that adjoins the opening 14, as depicted in figures 1 and 2.
In the exemplary embodiment, the part of the hologram 22 that lies over the through opening 14 forms a laser modification region 24 in which the visual appearance of the hologram 22 is modified by the action of laser radiation and that, according to the present invention, is in perfect register with the through opening 14.
This makes it possible to align a motif depicted by the hologram 22, 24 with the shape or contour of the through opening 14 without register variation and, in this way, to create a visual or content-based interaction between the opening 14 and the hologram motif 22, 24, as illustrated in the following with reference to some specific exemplary embodiments. In this way, both the attention and recognition value of the hologram 22, 24 and its counterfeit security are increased, since the perfect alignment of the two elements,

- 19 -opening 14 and laser modification region 24, presents a high barrier for a potential counterfeiter.
The manufacturing sequence and a first example of a visual and content-based interaction between opening and hologram will now be illustrated with reference to the top views in fig. 3.
In manufacturing a security paper according to the present invention, with reference to fig. 3(a), first, a foil strip 30 is provided with a metalized hologram, for example a true-color hologram 32, that includes, for example, a motif, depicted only schematically in the figure, having a mountain chain 34 and sky 36. Further, introduced into the security paper 40 by laser cutting, is a multi-part through opening 42 that depicts, as the motif, a sun having concentric rays, as shown in fig. 3(b). It is also well possible to introduce simpler shapes into the security paper by punching instead of by laser cutting.
The foil element 30 having the hologram 32 is now applied to the top 47 of the security paper 40 in such a way that the opening 42 is located in the region of the sky 36 of the hologram 32. Then the foil element 30 is impinged on from the bottom of the security paper 40 through the opening 42 with laser radiation, for example the radiation of a pulsed Nd:YAG laser at 1.064 gm, and in this way, the metal layer of the hologram 32 demetalized in the regions lying over the opening 42.
The demetalized regions of the hologram then form a laser modification region 38 in which the visual appearance of the hologram 32 is modified, as shown in fig. 3(c). Since the opening 42 serves as a mask when demetalizing

- 20 -the hologram 32, the laser modification region 38 is perfectly registered with the cut edges of the opening 42.
The unavoidable registration tolerances when applying the foil element 30 to the security paper 40 are taken up - not perceptibly for the viewer - by the sky 36 motif portion of the hologram 32, but they do not effect any registration tolerances between the opening 42 and the laser modification region 38. In this way, the laser modification region 38 and the opening 42 can be coordinated with each other in the design without consideration for registration tolerances. In the exemplary embodiment in fig. 3, the laser modification region 38 is, for example, coordinated with the opening 42 visually and in terms of content in that both regions depict, offset-free, the same motif (sun with rays). In the context of the present invention, also more complex interactions can, of course, be produced, as described in greater detail below.
In one development, the surroundings of the laser modification region 38 to be expected can be provided with dyes or feature substances to vary the visual impression of the laser modification region 38 as desired. For example, the surrounding region of the laser modification region 38 to be expected of the hologram 22 can be provided with an optically variable layer, such as a color-shifting liquid crystal layer. After the application to the security paper and the demetalization in the region 38, the opening 42 then appears light when looked through, while the optically variable effect of the liquid crystal layer stands out clearly when the security paper 40 is laid on a dark background. Here, the desired color impression of the liquid crystal layer can be set, for example, through the choice of the liquid crystal material and the thickness of the optically variable layer.

- 21 -Fig. 4 shows another development of the exemplary embodiment in fig. 3, in which, through register effects, the through opening 42 is integrated not only on one, but rather on both sides of the security paper 40. Here, fig. 4(a) shows a cross section through the security paper 40, and figures 4(b) and (c) show a top view of the top and bottom, respectively, of the security paper 40 in the region of the hologram or the through opening.
To provide the security paper with register effects on both sides, before the cutting of the through opening 42, the security paper 40 was provided in a surrounding region 44 of the opening to be produced with a laser modifiable marking substance that changes its color, for example from transparent to red, through the action of the radiation of a CO2 laser at 10.6 gm, but that is not modified by laser radiation at 1.064 gm or 532 nm.
If the opening 42 is now cut in the security paper 40 from the bottom 46 with a CO2 cutting laser, then, due to the Gaussian beam profile of the laser beam, the threshold energy for the transformation of the marking substance from transparent to red is even exceeded in an edge region 48 of the opening 42. In this way, the opening 42 is thus produced having a circumferential red border 48 on the bottom 46 of the security paper 40.
To complete the design 50 of the bottom 46, the security paper 40 can optionally additionally be impinged on with CO2 laser radiation of lower laser energy in which only the threshold for the color transformation, but not the energy threshold required for cutting, is exceeded, such that additional colored regions 52 are created on the bottom 46. Since the cutting of the opening 42, the coloring of the edge regions 48 and the coloring of the non-

- 22 -cut regions 52 are done with the same cutting laser beam in the same work step or in the same operation, the colored regions 48, 52 and the opening 42 are in perfect register with each other, as shown in fig. 4(c). Further details on the laser modifiable marking substances usable for this development, and on further variants of the coloring of the border or surrounding region of the through opening can be found in publication WO 2009/003587 Al.
After the application of the foil element 30 in fig. 3(a) to the security paper 40 in fig. 4(a) and the demetalization of the hologram in the laser modification region 38, the visual appearance depicted in fig. 4(b), which corresponds to the appearance in fig. 3(c), is created on the top of the security paper 40.
The design 50 of the bottom 46 is not modified in the demetalization, since the marking substance of the regions 44 does not react to the radiation of the Nd:YAG laser used for demetalization, or the energy, more precisely the exposure (energy per unit area), is not sufficient for a reaction. The latter applies especially when a heat-reactive dye is used.
Altogether, the finished security paper displays, from above and from below, respectively, the visual appearance depicted in fig. 4(b) and 4(c), the opening 42 being incorporated in a complete picture (landscape with sun and wheel with spokes) on both sides through register effects.
The radiation modification region of the security element can, as in the exemplary embodiments described thus far, cover the entire region of the through opening. However, the radiation modification region can also be present only in a portion of the area of the through opening and thus form a sub-pattern inside the area of the through opening. To produce such a

- 23 -radiation modification region that is perfectly registered with the opening and having a sub-pattern, the following procedure, for example, can be used:
In the exemplary embodiment in fig. 5, first, a foil element 60 is provided with a security element 62 that exhibits first and second fractional regions and 66 that interact to different extents with the electromagnetic radiation used for modification. For this, the fractional regions 64, 66 can be filled, for example, with metalized grating patterns whose grating lines are arranged rotated by 900 to each other, as indicated in fig. 5(a) through the different crosshatchings of the fractional regions 64, 66. Here, the shape of the fractional regions 64, 66 forms a desired motif, for example the letter string "PL" depicted in fig. 5(a).
The foil element 60 is then applied to a security paper 70 having a through opening 72 (fig. 5(b)), and impinged on from the bottom of the security paper 70 through the through opening 72 with linearly polarized laser radiation of an Nd:YAG laser.
If the polarization plane of the laser radiation is suitably oriented, said laser radiation is absorbed significantly more strongly by the fractional regions 64 than by the fractional regions 66, such that the energy or power of the laser radiation is sufficient for demetalizing the fractional regions 64, while it effects no demetalization in the more weakly absorbing fractional regions 66.
In this way, in the region of the opening 72, only the fractional regions 64 are selectively demetalized.
Since the through opening 72 serves as a mask for the regional demetalization, the laser modification region 74, formed by the demetalized

- 24 -regions, of the security element 62 is perfectly registered with the cut edges of the opening 72. The regions 66 not demetalized by the laser radiation continue without any offset from outside the opening 72 into the region of the opening 72, as depicted in the top view in fig. 5(c) and in cross section in fig. 5(d).
In advantageous embodiments, the different interaction of the fractional regions 64, 66 can be achieved through laterally differently pronounced gratings, one fractional region having a high absorption, and another region, that is not to be demetalized, having a low absorption. This corresponds to the embodiment shown in fig. 5. A particularly high absorption contrast between these fractional regions is achieved when surface plasmon polaritons (SPs) are excited in one grating fractional region and the other fractional region permits no such resonance excitation. Linearly polarized laser radiation of a predefined wavelength at a certain angle of incidence is preferably suitable as the beam source. SPs can result in total absorption of incident TM polarized light (E-vector stands perpendicular to the grating lines). For highly conductive metallic gratings, in contrast, the TE polarized light (E-vector parallel to the grating lines) is hardly absorbed. In this way, absorption contrasts of greater than 10, in the infrared range even >100, can be achieved through gratings having fractional regions oriented differently by 90 . The precious metals Au, Ag, Pt, but also Al, Cr and Ni are particularly suitable for the metalization.
For example, a rectangular reflection grating having a period of 1 pm and a trench width of 0.6 pm, upon incident radiation of a wavelength of 1,064 nm, an angle of incidence of 1 and TM polarization as a function of the trench depth, displays, for the metals Au, Al, Ag and Cu, pronounced absorption

- 25 -maxima that, for example for Ag and Cu at a trench depth of about 110 nm, almost reach a maximum absorption of 100%.
Since the position of the SPs in the wavelength spectrum depends not only on the grating period, but also on the grating profile and on the optical constant, an absorption difference can also be achieved in fractional regions in which these parameters of the grating vary. Further, it is possible to achieve a high absorption of TE polarized light and a lower absorption of TM polarized light through an appropriate design of a grating profile. Here, said absorption of the TE polarized light is based on a resonance effect that is pronounced particularly in deep grating patterns (trench depth > period/2).
The different interaction of the fractional regions 64, 66 can also be achieved in yet another way, for example through different, surface-enlarging relief patterns. In this case, the selectivity is based on the fact that, when a metal layer is vapor deposited on differently coarse relief patterns, a metal layer results that is that much thinner the coarser the relief is developed to be.
Furthermore, in a coarser patterning, in general, incident laser radiation is reflected more often and thus gives off more energy to the metalization, such that, overall, coarser relief patterns can already be demetalized with lower laser energy. The aspect ratio is key here. The greater the aspect ratio is, the better demetalization can be performed.
The fractional regions 64, 66 can thus also be developed having a coarse relief pattern (fractional region 64) and a fine relief pattern (fractional region 66) to facilitate selective demetalization of only the fractional regions 64.
Further details on the selective removal of only one of two or more fractional

- 26 -regions are described in publication WO 2006/079489 Al.
A further possibility to produce, in the security element, fractional regions that interact to different extents is based on the use of a metalized embossing pattern having systematically introduced elevations and depressions. For this, fig. 6 shows an exemplary embodiment in which a foil element 90 is applied by means of a hot-melt adhesive 84 to a security paper 80 having a through opening 82. The foil element 90 includes a support foil 92 that is provided on one side with a UV-curing embossing lacquer layer 94.
An embossing pattern having elevations 96 and depressions 98 is embossed in the embossing lacquer layer 94. Here, the terms elevation and depression refer to the surface of the support foil 92, such that the elements pointing downward in fig. 6(a) constitute elevations since, seen from the surface of the support foil 92, they rise above the depressions 98.
In the exemplary embodiment, the elevations 96 additionally exhibit a microrelief pattern in the form of a desired hologram. The entire embossing pattern having elevations 96 and depressions 98 is provided with a metal layer 100, for example composed of aluminum, that also forms a hologram metalization for the microrelief pattern of the elevations 96.
The metalized embossing pattern is further contiguously coated with a laser beam absorbing and/or laser beam reflecting lacquer 102 that fills the depressions 98 of the embossing pattern. The lacquer 102 can be, for instance, a UV lacquer of high thermal stability in which an infrared absorber having an absorption maximum in the near infrared is dispersed. After the application, the applied lacquer is squeegeed off, milled off or wiped off the surface of the embossing pattern, a technically unavoidable, thin toning film

- 27 -surface of the embossing pattern, a technically unavoidable, thin toning film normally remaining on the elevations 96 of the embossing pattern.
Altogether, in this way, a metalized embossing pattern having a lacquer application 102 that completely fills the depressions 98 of the embossing pattern and that is present in a thin toning film on the elevations 96 results, as depicted in fig. 6(a).
After the application to the security paper 80, the foil element 90 is impinged on from the bottom of the security paper 80 through the through opening 82 with laser radiation, for example the radiation of an Nd:YAG laser, as indicated by the arrows 86 in fig. 6(a).
Through the action of the laser radiation 86 on the metalization 100 that is coated with lacquer, the elevated regions 96 are demetalized while the metalization is preserved in the depressed regions 98. Specifically, due to the laser-absorbing and/or laser beam reflecting additive in the lacquer 102, not enough laser power reaches the metalization 100 in the depressions 98 to trigger a demetalization there. In contrast, the metalization of the elevations 96 covered merely by the thin toning film receives a high energy input and is demetalized. Here, the thin toning film can even promote the demetalization, since its absorption is often greater than the absorption of the metal layer itself.
Altogether, through the laser irradiation, the security document 110 shown in fig. 6(b) is created, in which the demetalized elevations 96 in the region over the opening 82 constitute a laser modification region 112 having a modified visual appearance that is perfectly registered with the cut edges of the opening 82. The region formed by the depressions 98 continues, coming

- 28 -82. The appearance of the security document 110 thus corresponds, in principle, to the diagram in fig. 5(c). For example, the depressions 98 can form the letter string "PL" and thus correspond to the fractional region 66 in fig. 5(c), while in the micropattern of the elevations 96, a background hologram can be encoded that corresponds to the fractional region 64 in fig.
5(c).
Further details and variants of the patterning method on the basis of a metalized embossing pattern having elevations and depressions are described in publication number WO 2009/100869 A2.
The embodiments in figures 5 and 6 permit numerous variants and modifications that result from the embodiment possibilities described in the cited documents WO 2006/079489 Al and WO 2009/100869 A2. For example, unlike as shown in fig. 6, also the non-demetalized depressions can exhibit microrelief patterns, or only the depressions, but not the elevations, can be provided with microrelief patterns. The patterns in the embossing lacquer are generally also perceptible without metalization. However, if the lacquer 102 in fig. 6 exhibits a similar refractive index as the embossing lacquer 94, the patterns can also be developed to be imperceptible.
In further variants, no patterns are provided in the metal region. For this, for example, the patterns (fig. 5) described in publication WO 2006/079489 can be chosen such that they are poorly visible with the eye, or the elevations and depressions (fig. 6) used for the demetalization are not provided with further patterns. In both cases, after the demetalization, in effect, a visual

- 29 -appearance as for the security element 120 shown in fig. 7 results, in which the differently interacting fractional regions 122, 124 outside the through opening 126 offer the same appearance for the naked eye. The fractional regions 122, 124 permit visual differentiation only inside the opening 126, where the first fractional regions 122 are modified by the laser radiation and form a radiation modification region 128 having a modified visual appearance. For illustration, in fig. 7, in a region 125 outside the opening, some of the fractional regions 122, 124 there that are not distinguishable with the naked eye are drawn in with dotted lines.
In the embodiments according to fig. 6, also a printing ink can be used as a layer that absorbs the laser radiation and prevents the demetalization. As in the view of the bottom of a security paper according to the present invention shown in fig. 8, in this way is visible on the bottom a colored pattern 130, in the form of the radiation modification region 112, that is in exact registration with the demetalization and with the through opening 82.
Here, for the layer structure, embodiments may be considered in which the metalization lies over the foil and said foil over the printing ink, or in which the metalization lies between the foil and the printing ink, or embodiments in which the metalization lies over the printing ink and said printing ink over the foil. The visual appearance in all three embodiments corresponds to that in fig. 8.
If the laser-absorbing lacquer in fig. 6 is chosen to be colored and a pattern is introduced into the lacquer, a two-color inverse motif that is registered with the hologram or matte pattern can be introduced. Here, if the variant is chosen in which the lacquer protects the metalization against the laser

- 30 -radiation, then a visual impression as in fig. 5(c) is created when viewed from the top, and a visual impression as in fig. 8 when viewed from the bottom.
Alternatively, also a variant can be chosen in which the demetalization is supported by the lacquer 102, as described in greater detail in publication number WO 2009/100869 A2. Here, the lacquer used is preferably applied rather thinly, such that it is easily possible to set a transparent appearance.
With a non-transparent lacquer, the see-through effect of the through opening would be lost.
The features described in connection with figures 5 and 6 also permit combination with each other. An additional design element compared with the surrounding region can then appear and/or disappear in the through opening.
It is possible to use the embodiments according to the present invention with particular advantage in a microoptical depiction arrangement that can especially be developed as a moire magnification arrangement, as a microoptical moire-type magnification arrangement or as a modulo magnification arrangement. The basic principle of such depiction arrangements is explained in publication WO 2009/000528 Al.
In the exemplary embodiment in fig. 9, a foil element 140 is applied by means of a hot-melt adhesive 164 to a security paper 160 having a through opening 162. The foil element 140 includes a support foil 142 that is provided on its top with a grid-like arrangement of microlenses 144 that form, on the

- 31 -surface of the support foil, a two-dimensional grating having a pre-chosen symmetry. The spherically or aspherically designed microlenses 144 preferably exhibit a diameter between 5 gm and 50 gm, especially a diameter between merely 10 gm and 35 fIM.
On the bottom of the carrier foil 142 is arranged a motif layer 146 that includes, subdivided into a plurality of cells, a motif image having micromotif elements 148. The arrangement of the grating cells likewise forms a two-dimensional grating having a pre-chosen symmetry. The grating period and the diameter of the grating cells of the motif image are on the same order of magnitude as those of the microlenses 144, so preferably in the range from 5 gm to 50 gm and especially in the range from 10 gm to 35 gm, such that the micromotif elements 148, like the microlenses 144, are not perceptible even with the naked eye.
In the case of a moire magnification arrangement, the grating of the grating cells differs slightly in its symmetry and/or in the size of its grating parameters from the grating of the microlenses 144, a moire-magnified image of the micromotif elements 148 being created, according to the type and size of the offset, when the motif image is viewed. Modulo magnification arrangements, in which the motif image need not be composed of a grating of periodically repeated individual motifs, constitute a generalization. For the functional principle of the modulo magnification arrangements and further details, reference is made to the above-mentioned publication WO 2009/000528 Al.
In the exemplary embodiment in fig. 9, the motif layer 146 includes an embossing lacquer layer 150 having elevations 152 and depressions 154 that

- 32 -were first contiguously coated with a metal layer 156, as fundamentally already described in connection with fig. 6. In the exemplary embodiment in fig. 9, the micromotif elements 148 are formed precisely by the depressions 154 in the embossing lacquer layer 150.
As in fig. 6, the metalized embossing pattern 150, 156 was coated with a laser beam absorbing lacquer 158 that fills the depressions 154 and forms a thin toning film on the elevations 152. The foil element 140 was then applied to the security paper 160 and subsequently impinged on from the bottom through the through opening 162 with laser radiation. In this way, the elevations 152 were demetalized in perfect register in the region over the opening 162, while the metal layer 156 was preserved in the depressions 154.
Outside the opening 162, the metal layer is completely present, unchanged, both on the elevations 152 and in the depressions 154.
In the finished security paper, when viewed, the moire-magnified micromotif elements 148 (depressions 154) are then perceptible only inside the opening 162 against the background of the demetalized elevations 152, while they are not perceptible outside the opening 162 due to the lack of contrast between the metalized depressions 154 and the metalized elevations 152.
Altogether, for the exemplary embodiment in fig. 9, a visual appearance as depicted in fig. 7 thus results, with, however, the stars 124, as the moire-magnified micromotif elements 148, migrating according to the chosen magnifier effect when the security paper is tilted, for example orthoparallactically to the tilt direction. Since the opening 162 served as the mask for the demetalization of the elevations 152, the change of the

- 33 -appearance from the stars 124 to the uniformly appearing metal layer takes place in each case, independently of the tilting of the security paper, precisely at the cut edge of the opening 162.
If, for example, the embossing lacquer layer 150 is additionally provided with microrelief patterns on the elevations, then also an appearance having a magnifier effect, corresponding to fig. 5(c), can be produced. The letters "PL"
then migrate due to the magnifier effect, the demetalization appears precisely at the boundary of the through opening. Inside the opening 162, the moire-magnified micromotif elements (depressions) are then perceptible against the background of the demetalized elevations, outside the opening 162 they are perceptible against the background of the microrelief patterns of the elevations, which form, for example, a background hologram.
If the laser-absorbing lacquer in fig. 9 is chosen to be colored, then the embodiments already described in connection with figures 5 and 6 can be realized also in microoptical depiction arrangements. If also the back of the support foil is laminated with lenses, then also the backs can be rendered having a microoptical magnifier effect.
The demetalized regions can also be arranged spanning the micropatterns, such that, in the region of the through opening, an inverse pattern is created that is formed by demetalized regions arranged in the pattern shape inside the metalization. The pattern-shaped demetalized regions can be designed, for example, in the form of geometric patterns or in the form of an alphanumeric character string.

- 34 -Fig. 10 shows a further exemplary embodiment of a moire magnification arrangement 170 that is structured in parts like the microoptical magnification arrangement in fig. 9, elements that correspond to each other being provided with identical reference signs. When the moire magnification arrangement 170 in fig. 10 is viewed, moire-magnified micromotif elements 174, 176 are perceptible inside and outside the opening 162, but their color impressions differ from each other.
In this embodiment, the motif image of the magnification arrangement consists of a colored motif layer 172 having micromotif elements 174, the color of the motif layer 172 being modifiable by the action of the laser radiation. For this, the motif layer 172 can include, for example, laser modifiable pig-ments, which are available to the person of skill in the art with different properties, especially with respect to their surface color, the color change under laser action, the threshold energy and the required laser wavelength.
After the application of the foil element having the motif layer 172 to the security paper 160, the micromotif elements 174 initially all have the same starting color. Due to a laser impingement from the bottom of the security paper 160 through the opening 162, a color change is then induced in perfect register in the motif layer 172 in the region of the opening 162, such that the micromotif elements 176 lying there change their color. When the magnification arrangement 170 is viewed, there thus appears a combination of moire-magnified micromotif elements 174 of a first color outside the opening and of moire-magnified micromotif elements 176 of a second color inside the opening.

- 35 -The color change can consist, besides in a transformation of a first color to a second color, also in a transformation of a transparent motif layer to a colored motif layer or in a bleaching of a colored motif layer. In the second-mentioned case, a colored magnifier effect is created that is visible only in the opening and perfectly registered with the opening, and in the latter case, a magnifier effect that is visible only outside the opening and ends precisely at the cut edges of the opening.
The use of laser radiation is not compulsory for the discoloration or bleaching out of a lacquer, rather, a color change can also be induced by UV
or IR exposure. For the lacquer in these variants to not already bleach out through daylight, the support foil 142 and/or the lacquer of the microlenses 144 is preferably furnished with appropriate UV or IR absorbers.
Fig. 11 illustrates a further exemplary embodiment of the present invention, in which the microoptical depiction arrangement 180 displays a change of the depicted motif image precisely at the cut edges of the through opening 162 of the security paper 160.
Outside the through opening 162, a first motif image is visible that consists of first moire-magnified micromotif elements 182 in the form of the numeric string "50, as depicted in the top view in fig. 11(b). Thus, the first micromotif elements 182 take up the information of the through opening 162, which is likewise developed in the form of the numeric string "50".
Inside the through opening 162, a second motif image is visible that consists of second moire-magnified micromotif elements 184 in the form of the euro symbol "C. The first and second micromotif elements 182, 184, or the

- 36 -opening 162 and the second micromotif elements 184, thus complement each other to form the denomination of the banknote "50 Ã". The change between the first and the second motif image takes place in perfect register at the cut edge of the through opening 162.
To produce the perfect registration of the image change, a foil element 190 is used, as shown in fig. 11(a), in which, on the bottom of a support foil 196, a two-layer lacquer system having two stacked lacquer layers 192, 194 of the same refractive index is arranged. Here, the first micromotif elements 182 are present as embossed patterns in the, seen from the support foil 196, upper lacquer layer 192, the second micromotif elements 184 as embossed patterns in the, seen from the support foil 196, lower lacquer layer 194. The opposite side of the support foil 196 is provided with a grid, composed of microlenses 144, that is coordinated with the grid of the micromotif elements 182, 184, as already described above.
In the region of the opening 162, the upper lacquer layer 192 of the lacquer system was now ablated in perfect register by laser impingement of the foil element 190 from the bottom of the security paper 160 and through the opening 162. Thus, when the surroundings of the opening 162 are viewed through the microlenses 144, only the second micromotif elements 184 in the form of the "C" symbol that are present in the lower lacquer layer 194 are visible inside the opening (fig. 11(b)).
Outside the opening 162, the two lacquer layers 192, 194 are present stacked immediately on top of one another. Since they exhibit the same refractive index, the light passing through from the embossed patterns 184 at the interface of the lacquer layers 192, 194 is not influenced, such that the second

- 37 -micromotif elements 184 are not perceptible outside the opening 162. Rather, there, only the first micromotif elements 182 appear in the form of the numeric string "5011, which, due to the refractive index difference at the interface between the upper lacquer layer 192 and the adjoining layer 198, for example a heat seal coating layer, are perceptible. If the layer 198 is dyed, then the first micromotif elements 182 outside the opening 162 appear colored, and the second micromotif elements 184 inside the opening 162, transparent.
Here, the upper lacquer layer 192 is developed to be thin to ensure that both the first 182 and the second micromotif elements 184 lie substantially in the focal plane of the microlenses 144 and appear sharp when viewed.
For the sake of simpler illustration, the first micromotif elements 182 and the second micromotif elements 184 are drawn congruently in fig. 11(a), but in practice, they generally are not stacked immediately on top of one another.
In further exemplary embodiments of the present invention, the security element that is arranged on the foil element is formed on the basis of a combination of microlenses and concave microreflectors in order to form a microoptical depiction arrangement that is visible both from above and from below.
With reference to the schematic sectional view in fig. 12, such a security element 201, applied, for example, to a banknote, comprises a support 203 that exhibits, on its top 204, embossed micropatterns 205, and on its bottom 207, in sections, multiple concave microreflectors 208 and multiple microlenses 209. The concave microreflectors 208 and the microlenses 209 are

- 38 -in a plane perpendicular to the drawing plane in fig. 12 in a grid having a fixed geometry, for example in a hexagonal grid, and thus arranged areally in a viewing element pattern.
Here, the support 203 comprises a PET foil 210 on which a first layer 211 that is composed of radiation-curing lacquer and that exhibits the micropatterns 205 is applied. A second layer 212 that is composed of radiation-curing lacquer and in which the inverse shape of the concave microreflectors 208 and the shape of the microlenses 209 is embossed is developed on the bottom of the PET foil 210.
The micropatterns 205 that form a micropattern object or micromotif M1 are likewise in a plane perpendicular to the drawing plane in fig. 12 in a grid having a fixed geometry, here for example likewise a hexagonal grid, and are thus arranged areally in a microstructure pattern, the microstructure pattern in this way being coordinated with the viewing element pattern and both patterns being aligned with each other such that, when the security element 201 is viewed from the top (direction of the arrow P1), the micropatterns 205 form, together with the concave microreflectors 208, a modulo magnification arrangement or a moire-magnification arrangement, as described in greater detail in the above-mentioned publications WO 2009/000528 Al and WO 2006/087138 Al. Here, the present micropattern object M1 corresponds to the motif image according to the teaching of WO 2009/000528 Al. For the viewing direction toward the top (direction of arrow P1), for a viewer, the micropattern object M1 is perceptible magnified as a security feature (target image within the meaning of WO 2009/000528 Al).

- 39 -To produce the concave microreflectors 208, the side of the second layer 212 facing away from the PET foil 210 is provided in the region A with a reflective coating 213, especially a metalization, such that the concave microreflectors 208 are developed as back-surface reflectors. In the exemplary embodiment, the inner side of the reflective coating 213 of each concave microreflector 208 or the embossed shape for the concave microreflectors 208 has the shape of a spherical cap having a radius of curvature of 38 um and a height of about 3 um. The layer thicknesses of the second layer 212, of the PET foil 210 and of the first layer 211 are chosen such that the micropatterns 205 are spaced just 1911M from the concave microreflectors 208 and thus lie in the plane of the foci of the concave microreflectors 208, such that the desired magnifying image of the micropatterns 205 is effected to produce a security feature.
In a region B of the security element 201, the metal layer 213 is removed by demetalization such that the embossed shapes there form, not concave microreflectors, but rather microlenses 209. Here, the radius of curvature of the convex side 214 of the microlenses 209 is the same as for the concave microreflectors 208 and thus measures, in the exemplary embodiment, 38 um, which results in a focal length of the microlenses 209 of about 115 um.
The plane E of the foci of the microlenses 209 thus lies outside the security element 201, such that the micropatterns 205 are not perceptible in the region B when viewed from the bottom 207 of the security element 201 (direction of arrow P2).
The microlenses 209 serve, not to image the micropatterns 205, but rather to verify another banknote or to self-verify the banknote of the security element 201. For self-verification, a further micropattern object that is not depicted in

- 40 -the drawing, and that the banknote includes in a position that is laterally spaced apart from the security element 201, is positioned in front of the top 204 of the support 203 of the security element 201 in the plane E by bending, buckling or folding the banknote, such that, in the viewing direction toward the bottom 207, the further micropattern object is imaged magnified by means of the microlenses 209.
To verify another banknote, the further micropattern image of another banknote is arranged in front of the top 204 of the security element 201 in the plane E to effect, by means of the microlenses 209, a magnified image through the bottom 207, such that a verification of the other banknote can be carried out.
According to the present invention, the demetalization of the metal layer 213 occurs after the application of the security element 201 to a security paper having a through opening and by radiation impingement of the metal layer 213 from the bottom 207 of the security element 201 through the through opening of the security paper, as already presented in detail above. In this way it is ensured that the transition from micromirrors 208 to microlenses 209 (boundary of regions A and B in fig. 12) occurs in perfect register at the cut edge of the through opening.
The concave microreflectors 208 and the microlenses 209 can also be developed in different planes, as shown in the sectional view in fig. 13. The structure of the layers 210 to 212 corresponds to the structure in fig. 12, the mirrored sides of the concave microreflectors 208 provided with a continuous metalization 213 being drawn in with solid lines (region A) in fig.

13. In the region B, the metalization 213 is partially removed by radiation

- 41 -impingement, such that semitransparent concave microreflectors 208' are created there, which are drawn in with dotted lines in fig. 13. Here, the metalization is especially superimposed with a subpattern, for example a dot or line grid, and completely removed in fractional regions corresponding to the subpattern, such that, overall, a semitransparent metalization is created.
To the layer 212 is affixed, by means of a laminating adhesive 221, a second PET foil 222 having a UV lacquer layer 223 developed thereon, the convex sides 214 of the microlenses 209 being embossed in the UV lacquer layer 223.
The convex sides 214 exhibit the shape of a spherical cap having a radius of curvature of 18 gm. Due to the radius of curvature of the convex sides 214 of the microlenses 209 of 18 gm, the microlenses 209 exhibit a focal length of 54 gm, which, for the chosen layer thicknesses, just corresponds to the spacing between the vertex of the convex sides 214 and the micropatterns 205.
Also in this exemplary embodiment, the demetalization of the metal layer 213 occurs after the application of the security element 201 to a security paper having a through opening and by radiation impingement of the metal layer 213 from the bottom 207 of the security element 201 through the through opening of the security paper and the second PET foil 222. In this way, a transition from the fully metalized micromirrors 208 to the semitransparent concave microreflectors 208' (boundary of the regions A and B in fig. 13) is produced that is perfectly registered with the cut edges of the through opening.
Outside the opening (region A), the micropatterns 205 are then visible for the viewer from above (viewing direction P1) through the reflecting, fully metalized micromirrors 208. Inside the opening (region B), the micropatterns

- 42 -205 are visible both from above and from below, specifically once (viewing direction P1) via reflection at the semitransparent concave microreflectors 208 and once (viewing direction P2) through the microlenses 209 and the semitransparent concave microreflectors 208.
Further details and advantages of the combination of microlenses and concave microreflectors can be found in German patent publication DE 10 2009 022 612 Al.
If the foil element is applied to the security paper by means of a hot-melt adhesive or another adhesive, then the hot-melt adhesive 84 can, due to the registration tolerances, protrude somewhat into the region of the opening 82, as fig. 6, for example, illustrates. This can result in a somewhat cloudy appearance in the edge region of the through opening. The adhesive can thus be developed to be laser ablatable in all embodiments, such that it can be applied contiguously and, upon modification, be ablated by the laser in the region of the opening 82. The adhesive layer is then likewise perfectly registered with the cut edges of the opening, as illustrated, for example, in fig. 11(a) for the hot-melt adhesive layer 198. For this purpose, the adhesive is preferably provided with appropriate absorbers for the laser radiation.
Instead of a simple metalization, as described and shown in the exemplary embodiments for illustration, also multilayer layer systems can be used. If the laser parameters are suitably chosen, individual layers can be removed from such layer systems in the region of the opening. For example, in a thin-film element that has a color-shift effect and typically consists of a reflection layer, a dielectric spacing layer and an absorber layer, only the reflection

- 43 -layer, a dielectric spacing layer and an absorber layer, only the reflection layer or also only the absorber layer can be removed by laser impingement.
The described modifications can, of course, be used not only in security papers, but also in other data carriers having through openings, for example in polymer notes or foil composite banknotes. Here, if only one foil is to be processed by the laser, then the second foil must be transparent for the laser, or the second foil is not yet applied in the laser processing step.

- 44 -List of Reference Numbers Banknote 12 Banknote paper 5 14 Through opening 16 Bottom 18 Top Foil strip 22 Hologram 10 24 Laser modification region Foil strip 32 True-color hologram 34 Mountain chain 36 Sky 15 38 Laser modification region Security paper 42 Through opening 44 Surrounding region 46 Bottom 20 47 Top 48 Edge region Design 52 Colored regions Foil element 25 62 Security element 64, 66 Fractional regions Security paper 72 Through opening

- 45 -74 Laser modification region 80 Security paper 82 Through opening 90 Foil element 92 Support foil 94 Embossing lacquer layer 96 Elevations 98 Depressions 100 Metal layer 102 Laser-beam-absorbing lacquer 110 Security document 112 Laser modification region 120 Security element 122,124 Fractional regions 125 Region outside the opening 126 Through opening 128 Radiation modification region 130 Colored pattern 140 Foil element 142 Support foil 144 Microlenses 146 Motif layer 148 Micromotif elements 150 Embossing lacquer layer 152 Elevations 154 Depressions 156 Metal layer 158 Laser-beam-absorbing lacquer

- 46 -160 Security paper 162 Through opening 162 Linearly polarizing layer 164 Hot-melt adhesive 170 Moire magnification arrangement 172 Motif layer 174, 176 Micromotif elements 180 Microoptical depiction arrangement 182, 184 Micromotif elements 190 Foil element 192, 194 Lacquer layers 196 Support foil 198 Adjoining layer 201 Security element 203 Support 204 Top 205 Micropatterns 207 Bottom 208 Concave microreflector 208' Semitransparent concave microreflectors 209 Microlenses 210 PET foil 211 Radiation-curing lacquer 212 Radiation-curing lacquer 213 Metal layer 214 Convex side of the microlenses 221 Laminating adhesive 222 PET foil

- 47 -223 UV lacquer layer

Claims (33)

Claims

1. A data carrier having - a window that extends from a bottom to a top of the data carrier, - a foil element having a security element that covers the window on the top of the data carrier, one portion of the security element lying over the window and one portion of the security element next to the window, characterized in that - the portion of the security element that lies over the window exhibits a radiation modification region that is in register with the window and in which the visual appearance of the security element is modified by the action of electromagnetic radiation.

2. The data carrier according to claim 1, characterized in that the data carrier is a value or security document.

3. The data carrier according to claim 1 or 2, characterized in that the security element exhibits a metal layer that is demetalized in the radiation modification region.

4. The data carrier according to claim 3, characterized in that the security element includes a metalized diffraction pattern, a metalized blazed diffraction pattern, a metalized matte pattern or a thin-film element having a color-shift effect.

5. The data carrier according to any one of claims 1 to 4, characterized in that the security element exhibits first and second fractional regions that interact differently with the electromagnetic radiation, both first and second fractional regions lying partially over the window and partially next to the window.

6. The data carrier according to claim 5, characterized in that the radiation modification region comprises only first, but not second, fractional regions, such that the second fractional regions display the same visual appearance over and next to the window.

7. The data carrier according to claim 5 or 6, characterized in that at least one of the two sub-regions exhibits an interference pattern.

8. The data carrier according to claim 7, characterized in that the interference pattern is a relief pattern in the form of a grating pattern that is defined by a grating constant and an orientation of the grating lines.

9. The data carrier according to any one of claims 5 to 8, characterized in that at least one of the two fractional regions exhibits a surface-enlarging relief pattern.

10. The data carrier according to claim 5 or 6, characterized in that the first and second fractional regions are formed by elevations and depressions of an embossing pattern.

11. The data carrier according to claim 10, characterized in that the depressions are filled with a radiation-reflecting and/or radiation-absorbing cover layer.

12. The data carrier according to any one of claims 1 to 11, characterized in that the security element includes micropatterns having a line width between about 1 µm and about 10 µm and whose visual appearance is modified in the radiation modification region.

13. The data carrier according to claim 12, characterized in that the micropatterns form, at least in the radiation modification region, a motif image that is subdivided into a plurality of cells, in each of which are arranged imaged regions of a specified target image

14. The data carrier according to claim 13, characterized in that the lateral dimensions of the imaged regions lie between about 5 µm and about 50 µm.

15. The data carrier according to any one of claims 12 to 14, characterized in that a viewing grid composed of a plurality of viewing grid elements is provided for reconstructing the specified target image when the motif image is viewed with the aid of the viewing grid.

16. The data carrier according to claim 15, characterized in that the lateral dimensions of the viewing grid elements lie between about 5 µm and about 50 µm.

17. The data carrier according to any one of claims 12 to 16, characterized in that the color of the micropatterns is modified in the radiation modification region.

18. The data carrier according to any one of claims 12 to 17, characterized in that the micropatterns inside and outside the radiation modification region each depict a different motif.

19. The data carrier according to any one of claims 12 to 18, characterized in that the micropatterns are present in a two-layer lacquer system having two stacked lacquer layers having substantially the same refractive index, a second motif image being embossed in the bottom lacquer layer and a first motif image in the top lacquer layer that is arranged over the bottom lacquer layer, and the top lacquer layer being removed in the radiation modification region such that, inside the radiation modification region, the second motif of the bottom lacquer layer is visually perceptible, and outside the radiation modification region, the first motif of the top lacquer layer.

20. The data carrier according to any one of claims 1 to 11, characterized in that - the security element comprises multiple reflective first micro-imaging elements arranged areally in a viewing element pattern, and transmissive second micro-imaging elements arranged areally in the viewing element pattern, - the first micro-imaging elements lying inside and the second micro-imaging elements outside the radiation modification region, - the security element further comprising a micropattern object that includes multiple micropatterns that are arranged in a microstructure pattern that is coordinated with the viewing element pattern in such a way that, by means of the first micro-imaging elements, the micropattern object is imaged magnified in front of the top, and an object plane region that lies outside the security element being allocated to the second micro-imaging elements such that the micropatterns of the micropattern object are not perceptible from the bottom when viewed by means of the second micro-imaging elements, but for verification, a further micropattern object having multiple micropatterns is positionable in the object plane region such that, by means of the second micro-imaging elements, the further micropattern object is imaged magnified in front of the bottom.

21. The data carrier according to claim 20, characterized in that the first micro-imaging elements are developed as concave microreflectors and/or the second micro-imaging elements as microlenses.

22. The data carrier according to any one of claims 1 to 21, characterized in that the window is developed in the form of a pattern or of characters or codes.

23. The data carrier according to any one of claims 1 to 22, characterized in that the window is formed by a through opening that extends from the bottom to the top of the data carrier.

24. The data carrier according to any one of claims 1 to 22, characterized in that the window is formed by a transparent region of the data carrier that extends from the bottom to the top of the data carrier.

25. The data carrier according to any one of claims 1 to 22, characterized in that the data carrier is multi-ply and the window comprises a through opening in at least one data carrier ply.

26. The data carrier according to claim 23 or 25, characterized in that the through opening is formed by a line grid composed of a plurality of parallel cutting lines.

27. The data carrier according to any one of claims 1 to 26, characterized in that the radiation modification region is developed in the form of a pattern or of characters or codes.

28. The data carrier according to any one of claims 1 to 27, characterized in that the foil element is applied to the top of the data carrier with a laser-ablatable adhesive layer, and the laser-ablatable adhesive layer is removed in the region of the window.

29. A method for manufacturing a data carrier, having the method steps:
a) providing a data carrier substrate having a window that extends from a bottom to a top of the data carrier substrate, and a foil element having a security element, b) covering the window on the top of the data carrier substrate with the foil element in such a way that a portion of the security element comes to lie over the window and a portion of the security element next to the window, and c) impinging on the security element from the bottom of the data carrier substrate and through the window with electromagnetic radiation to modify the visual appearance of the security element in a radiation modification region that lies over the window.

30. The method according to claim 29, characterized in that, in step c), the security element is impinged on with laser radiation.

31. The method according to claim 29 or 30, characterized in that, in step b), the foil element is applied to the top of the data carrier with a laser-ablatable adhesive, and in step c), a laser-ablatable adhesive that is present in the region of the window is removed.

32. The method according to any one of claims 29 to 31, characterized in that the window is formed by a through opening, or in that the data carrier is multi-ply and the window comprises a through opening in at least one data carrier ply, and in that, in step a), the through opening is introduced, by punching or by laser cutting with a cutting laser, into the data carrier substrate or the data carrier ply including the through opening.

33. The method according to claim 32, characterized in that - the data carrier substrate or the data carrier ply is provided with a laser-modifiable marking substance at least in the vicinity of the through opening to be produced, - the through opening is introduced into the data carrier substrate or the data carrier ply by the action of laser radiation, and - the laser-modifiable marking substance is modified in the vicinity of the opening by the action of laser radiation.