EP2385902B1 - Security element and security paper - Google Patents

Description

The invention relates to a security element for security or valuable documents and a security paper with a see-through security element, which is arranged in or over a window area or a through opening of the security paper.

Security or value documents, such as banknotes, identity cards and the like, are often equipped with security elements for security, which allow verification of the authenticity of the documents and at the same time serve as protection against unauthorized reproduction.

The security elements may be in the form of, for example, a security thread embedded in a banknote, a tearing thread for product packaging, an applied security strip, a cover sheet for a banknote with a through opening or a self-supporting transfer element, such as a patch or label after its manufacture is applied to a document of value. Increasingly transparent security features, such as transparent windows in banknotes, are becoming increasingly attractive. For window production, for example, a film provided with an adhesive layer on one side is applied to a banknote in order to close a previously produced through opening of the banknote.

Security elements with optically variable elements, which give the viewer a different image impression at different viewing angles, play a special role, since they can not be reproduced even with high-quality color copying machines. The security elements can do this with security features in the form of diffractive optical effective micro- or nanostructures are equipped, such as with conventional embossed holograms or other hologram-like diffraction structures, as for example in the publications EP 0 330 733 A1 or EP 0 064 067 A1 are described.

From the publication US 5 712 731 A the use of a moiré magnification arrangement is known as a security feature. The security device described therein has a regular array of substantially identical printed microimages of up to 250 μm in size, as well as a regular two-dimensional array of substantially identical spherical microlenses. The microlens array has substantially the same pitch as the microimage array. When the micro-image array is viewed through the microlens array, one or more enlarged versions of the microimages are created to the viewer in the areas where the two arrays are substantially in register.

The basic mode of operation of such moiré magnification arrangements is described in the article " The moire magnifier ", MC Hutley, R. Hunt, RF Stevens and P. Savander, Pure Appl. Opt. 3 (1994), pp. 133-142 , described. Thus, in short, moire magnification refers to a phenomenon that occurs when viewing a raster of identical image objects through a lenticular of approximately the same pitch. As with any pair of similar rasters, this results in a moiré pattern, which in this case appears as an enlarged and possibly rotated image of the repeated elements of the image raster.

document DE-A-102 005 062 132 discloses a security paper according to the preamble of claim 1.

On this basis, the invention has for its object to avoid the disadvantages of the prior art and in particular, a security element or to provide a security paper of the type mentioned above with high security against counterfeiting.

This object is achieved by the security paper and the security element having the features of the independent claims. A method for producing such security papers or security elements and a value document with such a security paper or security element are specified in the independent claims. Further developments of the invention are the subject of the dependent claims.

According to a first aspect of the invention, a security paper according to claim 1 is provided.

Although modern banknotes often have a large number of security features, the motifs represented by these features are as a rule not thematically linked to one another. The invention is based on the idea of providing a second security feature in addition to a first security feature in the form of a microoptical representation arrangement for displaying a first motif, which represents a second motif standing in a meaningful relationship to the first motif.

The meaning context is that the first and second motif have the same shape.

A sense context of the motives of the two security features leads to an increased protection against counterfeiting of the security paper or the security element, since the production of the content-related security features represents a larger technological hurdle than that separate or contentwise unlinked production of two security features.

The security features used in the security sector are usually already associated individually with a great deal of effort for the procurement of the necessary equipment for the production of the security feature and the necessary know-how. In addition, if the security features are interlinked in terms of content, the manufacturer must not only have the technologies for producing the features used, but must also be in a position to coordinate those features in a required manner in the form of one another in order to produce the desired meaning , If, for example, a micro-optical representation arrangement for displaying a given motif is combined with a continuous opening which is to have the same shape and size as the given motif, the manufacturer not only has to punch or cut suitable holes and produce micro-optical display arrangements, but must also use the micro-optical display arrangement additionally be generated with the correct magnification to achieve the desired congruence of reconstructed motif and aperture.

A further advantage of the configurations according to the invention is that a contextual linking of the various security features results in greater user attention and easier recognizability of adjustments: the lack of one of the security features or a quality inferior due to counterfeiting is much easier if the of the security features presented in a meaningful context. This also leads to an increase in attention to higher technological demands on the potential counterfeiter.

The micro-optical representation arrangement of the first security feature can be embodied in particular as a moiré magnification arrangement, as a moiré-type microoptical magnification arrangement or as a modulo magnification arrangement. The operating principle and the properties of these micro-optical representation arrangements are described in detail in the German patent applications DE 10 2005 062 132.5 . DE 10 2007 029 203.3 and DE 10 2007 029 204.1 , as well as in international applications PCT / EP2006 / 012374 . PCT / EP2008 / 005171 and PCT / EP2008 / 005172 described. The regions of the first motif imaged in the cells of the motif image of the microoptical representation arrangement are also sometimes referred to as micromotif elements in accordance with the terminology used in the aforementioned applications. As viewing elements, refractive microlenses and micromirrors are preferred, but other viewing elements mentioned in the publications cited above can also be used.

The information formed by the first and second motif is in particular an alphanumeric string, such as a serial number or a denomination of a banknote, a logo, an encoding or a graphic motif, which in particular represents objects of any kind, plants, animals or humans. The first subject can also be a sequence of images, showing, for example, a short story or the transformation of a subject into another subject (morphing).

In an advantageous variant of the invention, it is provided that the second security feature is formed by the window area or the continuous opening of the security paper and the second motif by the outline shape of the window area or the continuous opening.

The window area or the through opening can advantageously have a sharply delimited edge at least in a partial area, as can be generated for example by punching or laser cutting. Alternatively or additionally, the window region or the through opening advantageously has, at least in one subarea, an edge produced during papermaking with characteristic irregularities.

Especially attractive and tamper-proof variants use window areas or continuous openings with a combination of sharp and characteristically irregular edges. Such a combination can be produced, for example, by producing a continuous opening with characteristic irregularities in the edge region during papermaking and by modifying the edge region of the opening thus produced after papermaking by cutting or punching and thereby sharply limited in desired partial areas. Other ways to combine sharp and characteristically irregular border areas are in the document WO 2006/119896 A2 described.

• ein Durchsichtssicherheitselement mit dem ersten Sicherheitsmerkmal, das durch eine mikrooptische Darstellungsanordnung zur Darstellung des zumindest ersten Motivs gebildet ist, erzeugt,
• wird in dem Sicherheitspapier als zweites Sicherheitsmerkmal ein Fensterbereich oder eine durchgehende Öffnung erzeugt, und wird das zweite Motiv, das mit dem ersten Motiv in einem Sinnzusammenhang steht, durch die Umrissform des Fensterbereichs bzw. der durchgehenden Öffnung gebildet, und
• wird das Durchsichtssicherheitselement in oder über dem Fensterbereich oder der durchgehenden Öffnung angeordnet.

In a method for producing the above-described security paper is

• a see-through security element with the first security feature, which is formed by a micro-optical representation arrangement for representing the at least first motif, generates,
• For example, in the security paper, a window portion or a through hole is formed as a second security feature, and the second motif that is meaningful with the first subject is formed by the outline shape of the window portion and the through hole, respectively
• the see-through security element is placed in or over the window area or the through opening.

In a further, likewise advantageous variant of the invention, it is provided that the second security feature, like the first security feature, is present in the see-through security element.

The second security feature can advantageously represent a diffractive optical element that generates a traceable projection image with the second motif from a passing beam of substantially parallel light in transmission. Diffractive optical elements (DOEs) are typically diffractive structures embossed in transparent substrates, which are designed for monochromatic coherent laser radiation of a predetermined wavelength. If they are irradiated with a laser of suitable wavelength, registered images can be displayed on a projection screen.

The diffractive optical element used as a second security feature is preferably formed from a plurality of diffractive unit cells, which have a lateral dimension of about 1 mm, preferably also below 1 mm. The projection image of the diffractive optical element is preferably only visible under special lighting and viewing conditions with the naked eye and without aids, and a good representation of the projection image without colored edges is only achieved by irradiation with a suitable light source, such as a laser pointer. The projection image can then be captured on a screen.

Alternatively, the second security feature may advantageously be a refractive optical element that generates the second motif from a passing beam of substantially parallel light or from light from a remote point light source.

The refractive optical element used as a second security feature is preferably formed from a plurality of achromatic microstructure elements which have a lateral dimension below 1 mm, preferably between 3 μm and 100 μm. In preferred embodiments, the different achromatic microstructure elements are combined into higher-level units whose lateral dimension is preferably about 1 mm or less and which are arranged periodically or at least locally periodically in at least one spatial direction. Preferably, at least some of the microstructure elements are formed by microprisms, which are each characterized by the dimension of their base area, a refractive angle and an orientation of the microprism indicating azimuth angle. Alternatively or additionally, at least a part of the microstructure elements has a curved surface. These achromatic microstructure elements may be formed, for example, by microcones or micro-step cones, each through the diameter of their base and an opening angle are characterized.

In order to ensure that wavelength-dependent light diffraction effects are negligible and that the incident light is substantially achromatically refracted by the structural elements without disturbing color effects, the microstructure elements in each case have a lateral dimension above approximately 3 μm, preferably above approximately 5 μm, particularly preferred above about 10 μm. Further information on the possible embodiments and properties of such refractive optical elements can the document WO 2007/137744 A2 and the registration PCT / EP2008 / 002841 be removed.

In addition to diffractive and refractive optical elements, it is of course also possible to use other security features for the second security feature of the see-through security element, such as the optically variable layer systems with color-shifting thin-film elements or liquid-crystal features described below. Also possible is a combination with security features that create a blind effect, such as the one in the application PCT / EP2007 / 008953 described security features. Such a combination is preferably produced by special embossing structures and by metallization and area demetallization.

In the variants of the invention in which the second security feature is also present in the see-through security element, the window area or the through opening of the security paper can advantageously have a third security feature with one through the outline shape of the window area or the continuous opening formed third motif, which is in a sense context with the first and second motif. In particular, the third security feature may represent the same motif as the first and / or second security feature.

• ein Durchsichtssicherheitselement mit dem ersten Sicherheitsmerkmal, das durch eine mikrooptische Darstellungsanordnung zur Darstellung des zumindest ersten Motivs gebildet ist, und mit dem zweiten Sicherheitsmerkmal mit dem zweiten Motiv, das mit dem ersten Motiv in einem Sinnzusammenhang steht, erzeugt,
• wird in dem Sicherheitspapier ein Fensterbereich oder eine durchgehende Öffnung erzeugt, und
• wird das Durchsichtssicherheitselement in oder über dem Fensterbereich oder der durchgehenden Öffnung angeordnet.

In a method for producing the above-described security paper is

• a see-through security element with the first security feature, which is formed by a micro-optical representation arrangement for representing the at least first motif, and with the second security feature with the second motif, which stands in a meaningful relationship with the first motif,
• a window area or a through opening is produced in the security paper, and
• the see-through security element is placed in or over the window area or the through opening.

According to a second aspect of the invention, a see-through security element according to claim 8 is provided.

• ein Sicherheitselement mit dem ersten und zweiten Sicherheitsmerkmal erzeugt, wobei das erste Sicherheitsmerkmal durch eine mikrooptische Darstellungsanordnung zur Darstellung des zumindest ersten Motivs gebildet ist, und das zweiten Sicherheitsmerkmal das zweite Motiv bildet, das mit dem ersten Motiv in einem Sinnzusammenhang steht,
• wobei das zweite Sicherheitsmerkmal durch einen innerhalb des ersten Sicherheitsmerkmals angeordneten statischen Bildbereich und das zweite Motiv durch die Umrissform des statischen Bildbereichs gebildet wird, wobei in dem statischen Bildbereich keine Betrachtungselemenge vorgesehen sind oder die optische Wirkung der Betrachtungselemente neutralisiert ist und/oder keine abgebildeten Bereiche des ersten Motivs vorgesehen sind.

In a method for producing the above-described security element is

• generates a security element with the first and second security feature, wherein the first security feature is formed by a micro-optical representation arrangement for displaying the at least first motif, and the second security feature forms the second motif, which is in a meaningful relationship with the first motif,
• wherein the second security feature is provided by a static image area located within the first security feature and the second motif is formed by the outline of the static image area, wherein in the static image area no viewing quantity are provided or the visual effect of the viewing elements is neutralized and / or no imaged areas of the first motif are provided.

According to a third aspect of the invention, a see-through security element according to claim 9 is provided.

• ein Sicherheitselement mit dem ersten und zweiten Sicherheitsmerkmal erzeugt, wobei das erste Sicherheitsmerkmal durch eine mikrooptische Darstellungsanordnung zur Darstellung des zumindest ersten Motivs gebildet ist, und das zweiten Sicherheitsmerkmal das zweite Motiv bildet, das mit dem ersten Motiv in einem Sinnzusammenhang steht,
• wobei das zweite Sicherheitsmerkmal durch einen Bereich mit einem optisch variablen Schichtsystem und das zweite Motiv durch die Umrissform dieses Bereichs gebildet wird.

In a method for producing the above-described security element is

• generates a security element with the first and second security feature, wherein the first security feature is formed by a micro-optical representation arrangement for displaying the at least first motif, and the second security feature forms the second motif, which is in a meaningful relationship with the first motif,
• wherein the second security feature is formed by an area with an optically variable layer system and the second motif by the outline of this area.

Security elements which are nontransparent, for example metallized and designed to be viewed from above, are not part of the invention. This may be the case, for example, when micro-cavity mirrors are used as viewing elements. Also in the embodiments of the second and third aspect of the invention, the first and second motif are always in a sense context, wherein the statements made in connection with the first aspect of the invention on the meaning and the formation of this feature also apply here.

In an advantageous variant of the invention, the second security feature is formed by a region with a thin-film element with a color-shift effect. Such thin-film elements typically have a reflective layer, an absorber layer and an intermediate between the reflective layer and the absorber layer disposed dielectric spacer layer. The color shift effect is based on viewing angle dependent interference effects due to multiple reflections in the different sublayers of the element. If the thin-film element is to be made semitransparent, for example for use in a see-through security element, then the thin-film element can consist of a dielectric layer enclosed by two thin metal layers, the metal layers in this case being made so thin that they are partially translucent. Alternatively, the thin-film element can also be formed from a sequence of dielectric layers with different refractive indices.

In an equally advantageous variant of the invention, the region with an optically variable layer system is additionally provided with embossed structures which lead to a louver effect and / or additionally modify the color-shift effect. Such embossed structures can be formed for example by sawtooth structures.

According to a further, likewise advantageous variant of the invention, the second security feature is formed by a region having a liquid-crystalline material, for example a cholesteric liquid-crystal layer with the outline shape of the second motif.

In the variants of the invention in which the second security feature is formed by a color-variable layer system, a further coordination between the first and second security feature can be provided. For this purpose, the imaged areas of the first motif are executed in color, so that the first motif appears when viewed in a predetermined color. The color impression of the optically variable layer system is then for consideration adjusted to the color of the first subject under predetermined viewing conditions. At the predetermined viewing conditions, the optically variable layer system shows the same color as the enlarged images of the microoptical display, while in other viewing conditions the color shift effect of the optically variable layer system results in color differences between the two motifs.

When adapting the colors of the optically variable layer system and the imaged areas of the first motif, it should also be taken into account that the imaged areas of the first motif in some embodiments can be multicolored and / or their color can change as a function of tilting angle. To produce multicolored embodiments, for example, a feature region of the first motif may contain metallic nanostructures in which volume or surface plasmons are excited by the incident electromagnetic radiation and / or resonance phenomena are caused. The second motif is formed by a color-variable layer system, which for this purpose have a certain contour shape and / or can be created as a raster image.

The invention further includes a document of value such as a banknote, an identity card and the like, with a security paper or security element of the type described above. The term "security paper" is understood as a precursor to a value document that can not yet be processed and which can have further authenticity features in addition to the security element , Security paper is usually in quasi-endless form and will be further processed at a later date.

The security elements according to the invention can be introduced into a wide variety of substrates. In particular, these may be in or on a paper substrate, a paper with synthetic fibers, ie paper with a proportion x polymeric material in the range of 0 <x 100 wt .-%, a plastic film, for. As a film of polyethylene (PE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polypropylene (PP) or polyamide (PA), or a multilayer composite, in particular a composite of several different films (composite composite) or a paper-film composite (foil / paper / foil or paper / foil / paper), wherein the security element can be provided in or on or between each of the layers of such a multilayer composite.

The security elements according to the invention can therefore not only be formed on a carrier film from which they can be transferred in a known manner to a security paper or document of value. It is also possible to design the security elements directly on the value document or security paper. Thus, embossed structures in the form of refractive microlenses and optionally diffractive or refractive optical elements can be produced directly on a plastic film of the value document or security paper in order to form a security element according to the invention, for example in the case of plastic banknotes or film composite banknotes.

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

Fig. 1

eine schematische Darstellung einer Banknote mit einem erfindungsgemäßen Durchsichtssicherheitselement,

Fig. 2

die Banknote der Fig. 1 im Querschnitt,

Fig. 3

schematisch den Schichtaufbau einer mikrooptischen Darstellungsanordnung im Querschnitt,

Fig. 4

einen vergrößerten Ausschnitt der Banknote der Fig.1 im Bereich der durchgehenden Öffnung,

Fig. 5

ein weiteres Ausführungsbeispiel eines erfindungsgemäßen Sicherheitspapiers mit aufeinander abgestimmten ersten und zweiten Motiven, wobei (a) das visuelle Erscheinungsbild bei Betrachtung aus einer allgemeinen Betrachtungsrichtung und (b) das Erscheinungsbild bei genau eingepassten Motiven zeigt,

Fig. 6

in (a) und (b) zwei Gestaltungen, bei denen sich die beiden Motive schlüssig zu einem Gesamtbild ergänzen, die nicht Teil der Erfindung sind,

Fig. 7

ein weiteres Ausführungsbeispiel der Erfindung, bei dem sowohl das erste als auch das zweite Sicherheitsmerkmal in dem Durchsichtssicherheitselement vorliegen, wobei (a) das Sicherheitspapier im Querschnitt und (b) einen vergrößerten Ausschnitt im Bereich der durchgehenden Öffnung in Aufsicht zeigt,

Fig. 8

ein erfindungsgemäßes Sicherheitselement, bei dem das zweite Sicherheitsmerkmal durch einen innerhalb der mikrooptischen Darstellungsanordnung angeordneten statischen Bildbereich gebildet ist,

Fig. 9

ein weiteres erfindungsgemäßes Sicherheitselement, bei dem das zweite Sicherheitsmerkmal durch einen Bereich mit einem optisch variablen Schichtsystem gebildet ist,

Fig. 10,11

zwei Folienaufbauen für erfindungsgemäße Sicherheitselemente mit farbkippenden Dünnschichtelementen als zweitem Sicherheitsmerkmal, und

Fig. 12

eine Weiterbildung der Gestaltung der Fig. 6(a).

Show it:

Fig. 1

a schematic representation of a banknote with a see-through security element according to the invention,

Fig. 2

the banknote of Fig. 1 in cross section,

Fig. 3

schematically the layer structure of a micro-optical representation arrangement in cross-section,

Fig. 4

an enlarged section of the banknote Fig.1 in the area of the through opening,

Fig. 5

a further embodiment of a security paper according to the invention with coordinated first and second motifs, wherein (a) shows the visual appearance when viewed from a general viewing direction and (b) the appearance with precisely fitted motifs,

Fig. 6

in (a) and (b) two designs in which the two motifs coherently complement one another to form an overall picture, which are not part of the invention,

Fig. 7

a further embodiment of the invention, in which both the first and the second security feature in the see-through security element, wherein (a) shows the security paper in cross section and (b) an enlarged section in the region of the through opening in plan view,

Fig. 8

a security element according to the invention, in which the second security feature is formed by a static image area arranged within the microoptical representation arrangement,

Fig. 9

a further security element according to the invention, in which the second security feature is formed by an area with an optically variable layer system,

Fig. 10,11

two film assemblies for security elements according to the invention with color-shifting thin-film elements as a second security feature, and

Fig. 12

a development of the design of Fig. 6 (a) ,

The invention will now be explained using the example of security elements for banknotes. Fig.1 shows a schematic representation of a banknote 10 with a see-through security element 12, which is arranged over a see-through area, such as a window area or a through opening 14 of the banknote 10. Fig. 2 shows the bill 10 along the line II-II of Fig.1 in cross section.

In order to increase the security against counterfeiting, the banknote 10 contains two security features relating to one another in terms of meaning, which represent two motifs spatially arranged in their arrangement, shape and size. As a result of this measure, in addition to the security against counterfeiting, the recognizability of the security features and the user's attention are also increased, as explained in more detail below.

The first security feature in the see-through security element 12 is a micro-optical representation arrangement for displaying at least one first motif. As explained in more detail above, such a microoptical display arrangement can be designed in particular as a moiré magnification arrangement, as a moiré-type microoptical magnification arrangement or as a modulo magnification arrangement.

For a brief illustration of the basic principle of such representation arrangements shows Fig. 3 schematically the layer structure of a micro-optical representation arrangement 30 in cross section, wherein only the parts required for the explanation of the layer structure are shown. The micro-optical representation arrangement 30 contains a carrier 20 in the form of a transparent plastic film, for example an approximately 20 μm thick polyethylene terephthalate (PET) film. The upper side of the carrier film 20 is provided with a grid-like arrangement of microlenses 22 which form on the surface of the carrier film a two-dimensional Bravais grid with a preselected symmetry. The Bravais grating, for example, have a hexagonal lattice symmetry. However, other, in particular lower symmetries and thus more general forms, such as the symmetry of a parallelogram grating, are also possible.

The spacing of adjacent microlenses 22 is preferably chosen as small as possible in order to ensure the highest possible area coverage and thus a high-contrast representation. The spherically or aspherically configured microlenses 22 preferably have a diameter between 5 μm and 50 μm and in particular a diameter between only 10 μm and 35 μm and are therefore not visible to the naked eye. On the underside of the carrier film 20, a motif layer 26 is arranged, which is a motif image divided into a plurality of cells 24 with micromotif elements 28 contains. The arrangement of the grid cells 24 also forms a two-dimensional Bravais grid with a preselected symmetry.

In the case of a moiré magnification arrangement, the Bravais grating of the grating cells 24 differs slightly in its symmetry and / or in the size of its grating parameters from the Bravais grating of the microlenses 22. Depending on the nature and size of the difference arises when viewing the motif image an enlarged image of the micromotif elements 28.

The grating period and the diameter of the grid cells 24 are of the same order of magnitude as those of the microlenses 22, ie preferably in the range of 5 .mu.m to 50 .mu.m and in particular in the range of 10 .mu.m to 35 .mu.m, so that the micromotif elements 28 itself usually also have unrecognizable to the naked eye.

The optical thickness of the carrier film 20 and the focal length of the microlenses 22 are coordinated so that the motif layer 26 is located approximately at a distance of the lens focal length. The carrier film 20 thus forms an optical spacer layer, which ensures a desired, constant spacing of the microlenses 22 and the motif layer 26 with the motif image.

In the embodiments according to the invention, the micro-optical representation arrangement contains a motif image 26, which is divided into a plurality of cells 24, in each of which imaged areas 28 of the first motif are arranged, and a viewing grid of a plurality of viewing elements 22. When viewing the motif image 26 with the viewing grid, the first motif from the imaged areas arranged in the cells 28 is reconstructed, the first motif depending on the interpretation of the representation arrangement can float in front of and / or behind the image plane or lie in the image plane.

Such micro-optical display arrangements 30 also allow impressive motion effects, as explained in more detail in the above-mentioned publications. For example, the grid parameters of the arrangement of the imaged areas and the viewing grid can be matched to one another such that when the display arrangement 30 is tilted, an orthoparallactic motion effect results, in which the first motif moves perpendicular to the tilt direction and not parallel to it, as one would intuitively expect.

Regarding Fig. 4 showing an enlarged section 40 of the banknote 10 in the area of the through opening 14, the first motif of the first security feature is formed by a plurality of stars 42, which are reconstructed in the manner discussed above when viewing the microoptical display arrangement 30. In the exemplary embodiment, the representation arrangement 30 is designed such that the stars 42 move horizontally back and forth during the vertical tilting of the arrangement (tilting direction 44) (movement direction 46). Conversely, when horizontally tilted, the stars 42 move vertically up and down, thus showing an orthoparallactic motion effect in both tilt directions. However, motion effects are also particularly preferred in which the enlarged motifs, when tilting the security element relative to the tilting direction, move neither purely horizontally nor purely vertically but in a general direction.

This first security feature is now combined with a second security feature with a second motif, which in the embodiment is formed by the outline 48 of the through hole 14 and which is in a sense context with the first motif. In the embodiment of Fig. 4 the motifs 42, 48 are related to one another in that both motifs 42, 48 are designed as seven-pointed stars of identical shape, ie represent the same image information with different sizes.

The first motif reconstructed by the micro-optical representation arrangement 30 can also contain a plurality of different partial motifs. For example, the stars 42 of the Fig. 4 when looking at the picture plane not only all seem to float in the same, but also in different levels. It is also possible for some of the sub-motifs to float in front of, while other sub-motifs float behind the image plane. The partial motifs, in this case the stars 42, are in each case miniaturized images of the outline 48 of the opening 14, and have the same shape as the latter. The partial motifs can generally be reconstructed with different sizes, wherein, for example, the sub-motifs hovering above the image plane are larger, the sub-motifs hovering below the image plane can be made smaller.

The contextual linking of the two different security features by the same illustrated motif leads to a higher attention of the user and to a higher recognition value of the banknote, so that the user easily notices the lack of one of the two security features or due to a forgery inferior quality.

Fig. 5 shows a further embodiment of a security paper according to the invention with coordinated first and second motif.

In the embodiment shown, a banknote 50 has a through opening 52 whose outline 54 follows the outline of the denomination of the banknote, for example the numerical sequence "50". The opening 52 is covered with a see-through security element 12 with a micro-optical representation arrangement 30 of the type already described above.

In the embodiment of Fig. 5 The micro-optical representation arrangement 30 also reconstructs the number sequence "50" as a motif. The imaged regions 28 and the magnification of the representation arrangement 30 are hereby chosen such that the reconstructed first motif 56 has the same shape and size as the outline shape 54 of the opening 52. In addition, the first subject 56 is provided with a motion effect on tilting the display assembly 30, which may be described together with the magnification by an enlargement and movement matrix, such as in the application DE 10 2007 029 203.3 explained in more detail.

Due to the movement effect, the reconstructed first motif 56 coincides with the outline 54 of the opening 52 only when viewed from certain viewing directions. Fig. 5 (a) shows the visual appearance when viewed from a general viewing direction in which the reconstructed first subject 56 is shifted from the outline 54 of the opening 52. Only by suitable horizontal and vertical tilting of the presentation arrangement 30 succeeds to fit the subject 56 exactly in the outline 54, as in Fig. 5 (b) shown.

In addition to a high degree of conspicuity and high recognition value, the banknote 50 also has a high security against counterfeiting, since not only a suitable opening 52 and a microoptical display arrangement 30 for producing the number sequence "50" are produced in the production but the display assembly 30 must also be provided with the correct orientation and magnification to fit the digit sequence "50" exactly in the intended outline of the opening 52.

Other possibilities for matching the first and second motives of a security paper are in Fig. 6 shown. Instead of presenting the same information or parts of the same information twice, the two motifs can also be conclusive information complementary to an overall picture. Fig. 6 (a) shows a security paper 60 with a through opening 62, the outline 64 forms a bow window 66 and the silhouette 68 of a city. The opening 62 is combined with a see-through security element 12 with a micro-optical representation arrangement 30 of the type described above, which represents as a motive clouds 70 which move horizontally when tilting the display assembly 30 back and forth (direction of movement 72).

The magnification and movement matrix of the representation arrangement 30 can be selected such that the clouds 70 always move horizontally in the direction 72, regardless of the tilting direction of the arrangement 30. Such a design combines a high degree of conspicuity and a high recognition value with a high degree of protection against forgery, since the display arrangement 30, including the movement effect, must be precisely matched to the complex outline shape of the opening 62. Guidance on how to design the magnification and motion matrix to achieve the above effects is in the application PCT / EP2008 / 005172 described.

The sharp edges of with respect to the Figures 4,5 and 6 (a) Openings described can be well produced for example by punching or laser cutting. In alternative embodiments, the openings can also be produced paper-making with edges with characteristic irregularities. Particularly attractive and tamper-proof variants used apertures with a combination of sharp and characteristically irregular edges, which have already been generally described above.

With reference to the security paper 80 of the Fig. 6 (b) For example, the contour 84 of the opening 82 in the region of the sheet window 86 is generated by paper making and has an irregular edge there. In the area of the city silhouette 88, in which a higher accuracy is required, is like with Fig. 6 (a) produced by laser cutting a sharp edge area. The opening 82 with the two different edge regions 86, 88 is then combined in the manner described above with a micro-optical representation arrangement for representing the clouds 70. Depending on the physical size of the opening 82, in practice, the irregular edge of the arc window 86 may be realized only in the upper region of the window, since the distance of the city silhouette 88 to the edge of the arc window 86 in the lower window area may be too low.

Also in the other embodiments of the invention are each two security features with first and second, standing in a meaningful motives. The meaning context in the exemplary embodiments explained below is illustrated in each case by motifs of the same shape (seven-pointed stars).

According to another aspect of the invention, now with reference to the cross section of Fig. 7 (a) and the supervision of Fig. 7 (b) is explained in the context of the FIGS. 2 to 4 already described, formed by a micro-optical representation arrangement 30 first security feature combined with a second security feature with a second motif, which is also present in the above a through opening 14 of a security paper 90 see-through security element 92.

In the embodiment of Fig. 7 For example, the second security feature is a diffractive optical element 94 that generates a projection image 104 that can be captured on a screen 102 with the second motif from a transmitted beam 100 of substantially parallel light in transmission. According to the invention, the second motif is in a sense context with the first motif of the micro-optical representation arrangement 30 and, in the exemplary embodiment, likewise represents a seven-pointed star 104 with the same shape as the stars 42.

In order to combine the microoptical display arrangement 30 with the diffractive optical element 94, the area delimited by the contour 48 of the through opening 14 is divided into first area areas 96 and second area areas 98 in which the microoptical display arrangement 30 (first area areas 96) or the diffractive optical element 94 (second surface areas 98) is present. The division into first and second surface areas 96,98 can be done arbitrarily. In addition to divisions, which are based on the outline of the opening 14, as in FIG. 7 (b) For example, alternate sequences of stripes or rectangles may also be considered.

At the in Fig. 7 In the embodiment shown, the outline 48 of the opening 14 forms a third security feature with a third motif which, as in the exemplary embodiment of FIG Fig. 4 forms a seven-pointed star. The security paper 90 thus has three different security features, each representing the same motif or generate. In this case, the first security feature, namely the reconstructed stars 42 of the micro-optical representation arrangement 30, and the third security feature, namely the star-shaped outline 48 of the opening 14, readily visible to the naked eye. The second security feature, namely the star representation 104 encoded in the diffractive optical element 94, represents a higher-level security feature that is generated only when the see-through security element 92 is irradiated with a laser pointer 106 and can be collected on a screen 102. Under special lighting and viewing conditions, the star may also be visible to the naked eye.

For the second security feature of the see-through security element 12, it is also possible to use a refractive optical element instead of a diffractive optical element, which generates from a passing beam of essentially parallel light or from a distant point light source a second motif recognizable with the naked eye and without aids, such as in the publication WO 2007/137744 A2 and in the application PCT / EP2008 / 002841 described in more detail. Alternatively, the second motif can be projected onto a screen with a laser.

In producing the see-through security element 92, the structural elements of the diffractive optical element 94 or of the refractive optical element can be embossed together with the microlenses 22 of the micro-optical representation arrangement 30. The structures can be brought together with the microlenses on a tool with the highest register accuracy. The micromotif elements 28 of the depiction arrangement 30 can then be embossed over the entire area onto the back side of the film. It has been found that the functionality of the arranged on the front diffractive or refractive optical elements is practically not affected by such a back side embossing. Alternatively, however, those film regions which contain diffractive or refractive optical elements on their front side can also be recessed in the back side embossing of micromotif elements 28.

When viewed, enlarged images 42 in the regions equipped with diffractive or refractive optical elements, such as the second surface regions 98 of FIG Fig. 7 (b) not to be seen. This effect can be used for interesting combinations with motion effects of the micro-optic display assembly 30 since the moving enlarged images 42 will vanish on reaching the second surface areas 98, or appear to emerge from nowhere.

In micro-optic display arrangements 30 with colored micromotif elements 28, the areas provided with diffractive or refractive optical elements appear uniform in the color of the micromotif elements, but with a reduced color intensity corresponding to the area coverage of the micromotif elements.

In other embodiments not according to the invention, the security elements applied to the security paper may not only be see-through security elements but also nontransparent security elements in which the microstructures of the microoptical representation arrangement are made visible for example by metallization. The security elements described below may be transparent, partially transparent or non-transparent, depending on the desired purpose.

In all configurations, the security elements have a first security feature, which is formed by a micro-optical representation arrangement 30 for representing at least a first motif, and a second security feature with at least one second motif, which is in a meaningful context with the first motif.

In the embodiment 110 of Fig. 8 the second security feature is formed by a static image area 112 arranged inside the microoptical representation arrangement 30, in which either no microlenses 22 are provided, or in which the optical effect of the microlenses 22, for example by leveling the microlenses 22 with a transparent lacquer of sufficient thickness and the like Refractive index, neutralized. The second motif, which is meaningfully connected to the first motif, is formed by the outline 114 of the static image region 112. In the embodiment of Fig. 8 The static image area 112 likewise has the form of a seven-pointed star 114, thus representing the same motif as the stars 42 of the micro-optical representation arrangement 30.

In the static image area 112, due to the absence of microlenses 22 or due to the neutralization of their optical effect, no enlarged images 42 occur. Therefore, in micro-optical display assemblies 30 having motion effects, the images 42 appear to dissolve upon reaching the outline 114 of the static image area 112, or appear to emerge on the opposite side. Overall, the static image area 112 represents a fixed, colored area whose color impression is determined by the color of the micromotif elements of the representation arrangement 30. Again, the color intensity of the region 112 is reduced compared to the color intensity of the micromotif elements 28 corresponding to the area coverage of the micromotif elements.

If microvoided mirrors are used as viewing elements, as is not shown here, then they can be neutralized in some areas by recessed or subsequently removed the mirroring at the corresponding locations. If a continuous mirroring is used, the embossing of the micro-hollow mirrors in the corresponding areas can instead be dispensed with. For example, thin metal layers are suitable as silvering.

Fig. 9 shows a further embodiment 120 of the invention, in which the second security feature is formed by an area 122 with an optically variable layer system and the second motif by the outline shape of this area 122. In this embodiment, the optically variable layer system region 122 represents a plurality of seven-pointed stars 124, 126 which have the same shape as the stars 42 of the micro-optical representation arrangement 30. It is understood that the motif of the optically variable layer system region 122 also the enlarged images 42 to a Complete the overall picture or together with these can form a coherent overall picture.

Optically variable layer system region 122 may be within (star 126) as well as outside (stars 124) of the region of microoptical representation assembly 30, as in FIG Fig. 9 shown. The optically variable layer system may be a liquid crystalline material region, or what is presently preferred, a thin-film color-shifting element region.

Especially in the latter case, there are a variety of execution options. The thin-film element may be opaque or semitransparent. For opaque variants, layer sequences of absorber layer - dielectric layer - reflector layer are used, in which the reflector layer is formed so thick that it is opaque. Semitransparent thin film elements may also consist of a dielectric layer enclosed by two metal layers, in which case both metal layers are made thin enough to be partially transparent. Alternatively, a semitransparent layer sequence can also be produced from a sequence of dielectric layers with different refractive indices.

If such a security element is to be used in the region of a see-through window, then both semitransparent and completely reflective configurations are possible. In window-free areas, the use of completely reflective designs offers.

If the motif image 26 of the representation arrangement 30 consists of colored micromotif elements 28, then the color impression of the color-shifting thin-layer element can be adapted to this color when viewed under predetermined viewing conditions. Under these viewing conditions, the optically variable layer system region 122 then displays the same color as the enlarged images 42 of the microoptical representation assembly 30.

For example, the area 122 of the Fig. 9 be designed so that its color impression changes from magenta when viewed vertically to green at oblique viewing. Tuned to the micromotif elements 28 are also carried out in magenta, so that for the stars 42 results in a magenta color impression, which, unlike the color impression of the farbkippenden area 122, remains substantially unchanged when tilting the security element.

When viewed perpendicularly, the stars 42 which lie within the middle star 126 of the optically variable layer system region 122 are virtually invisible, since both the stars 42 and the color-shifting region 122 appear magenta. If the security element is tilted or the viewer changes its position, the color of the stars 124, 126 of the color-shifting region 122 changes from magenta to green, while the color of the enlarged stars 42 remains unchanged. The stars 42 then emerge clearly with a magenta appearance against a green background.

If the microstructures of the microoptical representation arrangement 30 are not colored but metallized, then this metallization layer can also be used as a reflector layer for the thin-film element. A corresponding foil structure of a security element 130 is shown in FIG Fig. 10 shown schematically in cross section.

In this case, the first motif formed by the micromotif elements 28 is reconstructed in a first region 132 when the metallized motif layer 26 is viewed through the microlenses 22. In the second region 134 is a color-shifting thin-film element 136, which comprises a partially transparent absorber layer 138 made of chromium, a vapor-deposited dielectric SiO ₂ spacer layer 140 and a reflection layer 142 formed by an opaque aluminum layer. The opaque reflection layer 142 of the second region 134 forms the metallization layer 26 of the microoptical representation arrangement 30 in the first region 132.

In the construction of the Fig. 10 For example, the thin-film element 136 is viewed through the microlenses 22, possibly modifying and / or attenuating its color-shifting properties. Alternatively, therefore, a film assembly 150 as in Fig. 11 in which the thin-film element 136 is applied to the viewer-facing side of the microlenses 22.

Another variant is the color-shifting coating differently than in the variant of Figure 10 in which the thin-film element 136 is arranged next to the surface area 132 occupied by micromotif elements 28, to be applied to the area occupied by micromotif elements. This can be done without a spacer layer, so that the color-shifting coating is applied directly to the area occupied by micromotif elements. In an alternative variant, it is also possible to separate the color-shifting coating by an additional spacer layer from the plane of the micromotif elements, resulting in the following structure: microlenses - optical spacer layer whose strength corresponds to the focal length of the microlenses, - level with the micromotif elements - additional spacer layer - color-shifting coating. In all cases results The second motif from the outline of the color-tilting coating, but it can also be created as a raster image.

In a further preferred embodiment, a semitransparent color-shifting layer system, which reproduces the information of the second motif, is brought between the microlenses and the motif layer, wherein the plane of the micromotif elements is still in the focus of the microlenses.

For the production of the film structure 150 of Fig. 11 can proceed as follows: First, the desired microstructures on the back of a PET film 152 are embossed. Then the microlens embossing takes place on the front side of the film, wherein no microlenses are embossed in the second region 134 in which the color-shifting thin-film elements are provided. Then, the first areas 132 provided with microlenses 22 are printed with a wash ink and the thin-film layer system 142, 140, 138 is vapor-deposited over the whole area. By washing out the wash paint, the vapor-deposited layers in the first region 132 are removed. Finally, the embossed microstructures of the back of the film are vapor-deposited over the entire surface with a metal layer 154.

If the microstructures are not vapor-deposited, but filled with paint, it may be advantageous to make the thin-film element semitransparent. The color of the microstructures then shimmers through the thin film element 136 and facilitates color matching of thin film element and microstructures.

The optically variable layer systems provided in the second regions 134 can also be applied semitransparently to the microlenses 22, without leveling or saving them. In this case, the enlarged images are visible through the optically variable layer system, such as in FIG Fig. 9 shown. If, instead of the semitransparent, optically variable layer system, a completely reflective color-shifting layer system is used, the enlarged images can only be seen in the released areas.

Fig. 12 shows a non-inventive development of already in connection with Fig. 6 (a) described design in which the security paper 160 has been provided in a vicinity of the through hole 162 with a laser-modifiable marker. In the region of the city silhouette 168, the laser-modifiable marking substance was then laser-shaped in the form of desired markings 164, for example the doors, windows or the one shown in the figure Church clock, modified.

In this case, both the sharp edge 166,168 of the opening 162 can be cut in the same operation with the same laser beam, as well as modified at reduced laser energy of the marker in the form of the labels 164. The locally introduced laser energy can be reduced by reducing the laser power and / or increasing the deflection speed of the laser beam. The markings 164 can thereby be precisely registered to the edge of the opening 162 and thus to the city silhouette 168. Further information about the equipment of security paper with laser-modifiable markers can be found in the registration form PCT / EP2008 / 004921 be removed.

Claims (17)

1. A security paper for manufacturing security or value documents (10) having a security element (12) that is arranged in or over a window region or a through opening (14) in the security paper,

   - the security element exhibiting a first security feature that is formed by a micro-optical depiction arrangement (30) for depicting at least a first motif (26, 42),

   - the micro-optical depiction arrangement including a motif image (26, 42) that is subdivided into a plurality of cells (24), in each of which are arranged imaged regions (28) of the first motif, as well as, composed of a plurality of viewing elements (22), a viewing grid that, when the motif image is viewed, reconstructs the first motif from the imaged regions arranged in the cells,

   - the security element being a see-through security element,

   - and the security paper exhibiting a second security feature (40) having at least one second motif (48) that is associated in meaning with the first motif,

   - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance.
2. The security paper according to claim 1, characterized in that the first and second motif are spatially coordinated with each other in arrangement, color, shape and/or size.
3. The security paper according to claim 1 or 2, characterized in that the second security feature is formed by the window region or the through opening in the security paper and the second motif by the contour shape of the window region or of the through opening.
4. The security paper according to claim 3, characterized in that the window region or the through opening exhibits a sharply delimited edge at least in a sub-region, and/or in that the window region or the through opening exhibits, at least in a sub-region, an edge produced at paper manufacture and having characteristic irregularities.
5. The security paper according to claim 1 or 2, characterized in that the second security feature is present in the see-through security element.
6. The security paper according to claim 5, characterized in that the second security feature is a diffractive optical element that, in transmission, produces from a penetrating beam of substantially parallel light a detectable projection image with the second motif, or in that the second security feature is a refractive optical element that produces the second motif from a penetrating beam of substantially parallel light or from light from a distant spotlight source.
7. The security paper according to claim 5 or 6, characterized in that the window region or the through opening in the security paper forms a third security feature having a third motif that is formed by the contour shape of the window region or the through opening and that is associated in meaning with the first and second motif.
8. A see-through security element for security or value documents, characterized in that

   - the see-through security element exhibits a first security feature that is formed by a micro-optical depiction arrangement for depicting at least a first motif,

   - the micro-optical depiction arrangement including a motif image that is subdivided into a plurality of cells, in each of which are arranged imaged regions of the first motif, as well as, composed of a plurality of viewing elements, a viewing grid that, when the motif image is viewed, reconstructs the first motif from the imaged regions arranged in the cells, and in that

   - the see-through security element exhibits a second security feature having at least a second motif that is associated in meaning with the first motif,

   - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance,

   - the second security feature being formed by a static image region arranged within the first security feature, and the second motif by the contour shape of the static image region, wherein, in the static image region, no viewing elements are provided, or the optical effect of the viewing elements is neutralized, and/or no imaged regions of the first motif are provided.
9. A see-through security element for security or value documents, characterized in that

   - the see-through security element exhibits a first security feature that is formed by a micro-optical depiction arrangement for depicting at least a first motif,

   - the micro-optical depiction arrangement including a motif image that is subdivided into a plurality of cells, in each of which are arranged imaged regions of the first motif, as well as, composed of a plurality of viewing elements, a viewing grid that, when the motif image is viewed, reconstructs the first motif from the imaged regions arranged in the cells, and in that

   - the see-through security element exhibits a second security feature having at least one second motif that is associated in meaning with the first motif,

   - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance,

   - the second security feature being formed by a region having an optically variable layer system and the second motif being formed by the contour shape of said region.
10. The see-through security element according to claim 8 or 9, characterized in that the first and second motif are spatially coordinated with each other in arrangement, color, shape and/or size.
11. The see-through security element according to at least one of claims 8 to 10, characterized in that the second security feature is formed by a region having a color-shifting thin-film element, or in that the second security feature is formed by a region having a liquid crystal material.
12. The see-through security element according to at least one of claims 8 to 11, characterized in that the imaged regions of the first motif are executed in color, and in that the color impression of the optically variable layer system is adapted to the color of the first motif when viewed under predetermined viewing conditions.
13. A value document, such as a banknote, identity card and the like, having a security paper according to at least one of claims 1 to 7 or a see-through security element according to at least one of claims 8 to 12.
14. A method for manufacturing a security paper according to one of claims 1 to 4, in which

    - a see-through security element having the first security feature, which is formed by a micro-optical depiction arrangement for depicting the at least first motif, is produced,

    - in the security paper, as the second security feature, a window region or a through opening is produced and the second motif, which is associated in meaning with the first motif, is formed by the contour shape of the window region or of the through opening,

    - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance,

    - the see-through security element is arranged in or over the window region or the through opening.
15. A method for manufacturing a security paper according to at least one of claims 1 to 2 and 5 to 7, in which

    - a see-through security element having the first security feature, which is formed by a micro-optical depiction arrangement for depicting the at least first motif, and having the second security feature having the second motif, which is associated in meaning with the first motif, is produced,

    - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance,

    - a window region or a through opening is produced in the security paper, and

    - the see-through security element is arranged in or over the window region or the through opening.
16. A method for manufacturing a see-through security element according to claim 8, in which

    - a see-through security element having the first security feature, which is formed by a micro-optical depiction arrangement for depicting the at least first motif, and having the second security feature having the second motif, which is associated in meaning with the first motif, is produced,

    - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance,

    - the second security feature being formed by a static image region arranged within the first security feature, and the second motif by the contour shape of the static image region, wherein, in the static image region, no viewing elements are provided, or the optical effect of the viewing elements is neutralized, and/ or no imaged regions of the first motif are provided.
17. A method for manufacturing a see-through security element according to claim 9, in which

    - a see-through security element having the first security feature, which is formed by a micro-optical depiction arrangement for depicting the at least first motif, and having the second security feature having the second motif, which is associated in meaning with the first motif, is produced,

    - the first and second motif constituting pieces of information that are related to each other and exhibiting the same shape, and the first and second motif being spatially coordinated with each other in their visual appearance,

    - the second security feature being formed by a region having an optically variable layer system, and the second motif by the contour shape of said region.

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