EP1800271B1 - Security document - Google Patents

Abstract

The invention concerns a security document (7) having a first transparent region (72) in which a first transparent optical element (74) is arranged and a second region (71) in which a second opaque optical element (73) is arranged. The second opaque optical element (73) exhibits a first optical effect. The first region (72) and the second region (71) are arranged in mutually spaced relationship on a carrier (75) of the security document, in such a way that the first and second regions can be brought into mutually overlapping relationship. Upon overlap of the second optical element with the first optical element with a first spacing (26) between the first and second optical elements a second optical effect appears and upon overlap of the second optical element with the first optical element with a second spacing (25) between the first and second optical elements, which is greater than the first spacing (26), a third optical effect (51) which is different from the second optical effect appears.

Description

The invention relates to a security document, in particular a banknote or a badge, which has a first area in which a first transparent optical element is arranged and a second area in which a second opaque optical element is arranged. The first region and the second region are in this case arranged on a flexible carrier of the security document in such a way that the first and the second region can be brought into overlap with one another, for example by bending, folding or twisting the flexible carrier.

That's how it is EP 0930979 B1 such as Zientek, "Polymeric self-authenticating banknotes", Proc. SPIE vol. 3314 a self-checking banknote is known, which consists of a flexible plastic carrier. The flexible plastic support is made of a transparent material and is provided with a clouded sheath, leaving a clear transparent surface as a window. In the flexible window, a magnifying lens is now arranged as a self-certification center. Furthermore, a microprint area is provided on the banknote, which shows a small character, a small line or a filigree pattern. For checking or inspecting the banknote, the banknote is folded and thus the transparent window and the micro-printing area are brought into coincidence. The magnifying lens can now be used to make the micro-pressure visible to the viewer and thus to verify the banknote. The magnification of the micropattern resulting for the observer is determined by the clear range of vision (in normal eyes 25 cm) and by the focal length of the magnifying lens. By the in EP 0930979 B1 proposed embodiment of the bill is thus hidden in the Banknote arranged security feature by means of a arranged on the banknote verification means indicated.

Next will be in EP 0256176 A1 a bank passbook is described with an encrypted identification mark which is printed on the inside of the rear book cover or on one side of the book and has means for authenticity verification in the form of a transparent area. The transparent area is configured as a read screen for decrypting the encrypted identifier as soon as that screen is overlaid with the area containing the encrypted identifier by closing the bookband.

The invention is based on the object of specifying an improved security document.

This object is achieved by a security document comprising a first transparent region in which a first transparent optical element is arranged, and a second region in which a second opaque optical element is arranged, which exhibits a first optical effect, wherein the first Region and the second region are arranged so spaced apart on a support of the security document that the first and the second region can be brought into coincidence with each other, and in the overlapping of the second with the first optical element at a first distance between the first and second A second optical effect is exhibited by the optical element and, when the second optical element is covered with the first optical element, at a second distance between the first and second optical elements which is greater than the first distance, a third optical effect different from the second optical effect is exhibited.

When the first and second optical elements are covered, a distance-dependent optical effect that is dependent on the distance between the first and the second optical element thus appears. Depending on whether the first and the second element are brought into overlap, and on depending on the spacing between the overlapping first and second optical elements, the optical effect that the viewer sees differs. The invention thus provides the user with a novel verification method that goes far beyond mere identification of an enhanced security feature. The invention makes it possible to provide security documents with particularly obvious, surprising security features that are particularly easy for the user to check. Furthermore, the invention opens up the possibility of integrating further security features into a security document in a particularly cost-effective manner. By using only one transparent and one opaque optical element, it is possible to provide the security document with three or more security features. This makes it possible to produce by means of the invention easily verifiable, cost manufacturable and difficult to imitate security documents.

Advantageous embodiments of the invention are designated in the subclaims.

According to a preferred embodiment of the invention, when the second with the first optical effect is overlapped with the first distance, a first pattern appears as a second optical effect and when the second with the first optical element is overlaid with the second distance, an enlarged representation of the first pattern as the third one optical effect. By reducing the distance between the optical elements, a reduction effect and enlargement of the distance have a magnification effect. Such an unexpected optical illusion effect is very obvious and easy to remember.

Particularly impressive effects can be achieved when the observer shows a diffractive pattern when the first and second optical elements are covered, which appears small at the first distance and considerably larger at the second distance.

Furthermore, it is also possible for the second distance to show a reduced or changed representation of the first pattern.

According to a further preferred embodiment, when the distance is reduced or increased in size, a disappearance of specific information and / or a change of information takes place so that different information is displayed to the viewer at the first and at the second distance. Furthermore, it is possible that at a third or fourth distance between the first and the second optical element show further different optical effects.

In this case, both the second and the third optical effect preferably differ significantly from the first optical effect, thus representing, for example, different information or significantly different size representations of an information.

According to a preferred embodiment of the invention, the opaque second optical element has a first layer structured according to a micropattern. Micropattern here means that the pattern is a high resolution pattern whose typical size is higher than the resolution of the human eye. The first transparent optical element has a transparent layer in which a convex lens having a focal length approximately corresponding to the second distance is superimposed with a lens pattern matched to the micropattern, which is made up of a plurality of refractive or diffractive micro-lenses of one focal length exists that corresponds to the first distance. If the distance between the overlapping first and second optical elements corresponds to the first distance, then the information coded in the deviation from pattern regions or parts of the pattern regions of the micropattern and lens raster is shown. If the distance between the overlapping first and second optical elements corresponds to the second distance, the observer is made to see the micropattern or parts of the micropattern. It is particularly advantageous in this implementation of the invention that the at different spacing of the overlapping first and information showing second optical elements can be largely independent of each other and a relatively abrupt, binary change of information can be achieved.

The micropattern preferably has a typical size of less than 100 μm, preferably 100 to 40 μm. Furthermore, the micropattern preferably consists of a multiplicity of identical, repetitive structural elements. The dimensions of the individual structural elements should be less than 200 μm. Such repetitive patterns allow simplified design and verification of second and third optical effects to the viewer.

Furthermore, it is also possible for the structure elements of the micropattern to be arranged in a different area distribution in the surface area of the second optical element, so that the first optical effect in the manner of a gray scale image resulting from direct observation of the further optical element depends on the areal density of the distribution of the structure elements is.

The first layer of the second optical element structured in accordance with the micropattern may be a color layer or a reflective layer, which is structured in accordance with the micropattern. Preferably, however, in a pattern region formed according to the micropattern, a diffractive structure is formed in the first layer so that the first to third optical effects exhibit a diffraction pattern. As a result, a particularly high degree of security against counterfeiting can be achieved.

Preferably, the convex lens is formed by a diffraction-optically active structure, which generates the effect of a convex lens by diffractive optics. The structure is preferably formed by a lattice structure continuously changing with respect to its lattice frequencies and optionally further lattice constants over the area region, which is either a binary structure or designed such that in each case one flank of the lattice grooves is parallel to one another and approximately parallel to one another Perpendicular to the main plane of the boundary layer, while the angle of the respective other edges of the grid surface with respect to a perpendicular to the main plane of the boundary layer over the surface area changes substantially continuously. The lattice depth of the lens structure is preferably less than 10 μm. The use of such a "diffractive lens" has the advantage over the use of a "refractive lens", for example a Fresnel magnifying lens, that the necessary structural depth is considerably reduced and accordingly large-area convex lenses can be integrated in the security document. It is also possible that the micro-lenses of the lens grid are realized as "diffractive lenses".

The superposition of the convex lens and the lens raster is preferably realized by dividing the second optical element into a plurality of adjacent first and second regions. In each of the first areas, one or more micro-lenses of the micro-lens grid are formed, and in the second areas, structures that form the convex lens are formed. The width and / or the length of the first and second regions is in each case below the resolution of the human eye. This type of superposition of the convex lens and the lens grid ensures high efficiency and luminosity of the lens grid and the convex lens.

Furthermore, it is also possible to form a grid of the structures forming the convex lens and the lens grid into a transparent layer of the first optical element.

According to a further preferred embodiment of the invention, the second optical element has a microstructured moiré pattern. The associated first optical element has an at least partially transparent layer in which is superimposed a moiré-pattern tuned moire analyzer and a convex lens having a focal length corresponding to the second distance and suitable for microstructuring the moire Visualize patterns. Is the distance between them overlapping first and second optical elements very low, a moire image is generated by superimposing the Moire pattern and the Moire analyzer. If the distance between the overlapping first and second optical elements is increased towards the second distance, the moire image is no longer generated and the observer is shown an enlargement of the microstructuring of the moire pattern. With a first distance between the first and second optical elements, the moiré image is thus displayed, and with a second distance between the first and second optical elements, an enlarged representation of the microstructuring of the moiré pattern.

In such a grid of a macroscopic lens with a microlens grid, for example, the macroscopic lens has a diameter of 3 mm to 50 mm, preferably 10 mm to 30 mm. The focal length of the macroscopic lens is preferably between half the diameter and ten times the diameter, in particular between one to five times the diameter. The microlens grid (e.g., square or hexagonal closest packing) has a plurality of microlenses in the range of 5 μm to 500 μm, preferably 50 μm to 200 μm. The focal length of the microlenses is between half the diameter and one hundred times the diameter, preferably between one to ten times the diameter.

Also, this embodiment of the invention has the advantage that the information shown as a second and as a third optical effect can be designed independently of each other and an abrupt, binary change of the information shown in distance increase / decrease can be realized. As a result, particularly memorable security features can be implemented in the security document.

According to a further preferred embodiment of the invention, the second optical element has a concave mirror element and the first optical element has a convex lens. When reducing the distance between the concave mirror element and the convex lens is the Increases the power of the system, so that the reflected image appears smaller. If the distance between the concave mirror element and the convex lens is increased, the magnification power of the system is increased and the reflected image appears larger. Thus, the already described reduction effect is achieved with distance reduction.

The image reduction / enlargement effect with the variation of the distance is unexpected to the observer because he intuitively expects the opposite. It is therefore easy for the people involved to remember the visual effect and to communicate it. Furthermore, it is very difficult to simulate such optical effects with commercially available technology, so that a high degree of security against counterfeiting is achieved.

The second optical element preferably has a replication lacquer layer and a reflective layer adjoining the replication lacquer layer, wherein a diffractive relief structure is formed in the interface between the replicating lacquer layer and the reflective layer and produces the effect of a concave mirror element by means of diffraction optics. The use of such a "diffractive" concave mirror element achieves the advantages already described above with regard to the use of a "diffractive lens".

It is possible that the second optical element only reflects the mirror image of the observer, who experiences the optical changes already described above when viewed through the superimposed first optical element.

Particular advantages are achieved in that the relief structure formed in the interface between the replication lacquer layer and the reflective layer is a superimposition of a structure that produces the effect of a concave mirror element and a diffractive structure that generates an optical pattern. Thus, it is possible that for example a hologram or KINEGRAM ^® is subjected when viewed through the first optical element of the above-described optical changes, ie that the size of the hologram decreases in distance reduction and increases in distance enlargement. Such an effect is very difficult to simulate with commercially available technologies.

Fig. 1

zeigt eine schematische Darstellung verschiedener Betrachtungssituationen eines erfindungsgemäßen Sicherheitsdokuments.

Fig. 2

zeigt eine Schnittdarstellung eines transparenten optischen Elements für ein erfindungsgemäßes Sicherheitsdokument nach Fig. 1.

Fig. 3

zeigt eine Schnittdarstellung eines opaken optischen Elements für ein erfindungsgemäßes Sicherheitsdokument nach Fig. 1.

Fig. 4a

zeigt eine schematische Darstellung einer Reliefstruktur für das optische Element nach Fig. 2.

Fig. 4b

zeigt eine schematische Darstellung einer weiteren Reliefstruktur für das optische Element nach Fig. 2.

Fig. 4c

zeigt eine Draufsicht einer Reliefstruktur für das optische Element nach Fig. 2.

Fig. 5

zeigt eine schematische Darstellung verschiedener Betrachtungssituationen eines erfindungsgemäßen Sicherheitsdokuments für ein weiteres Ausführungsbeispiel der Erfindung.

Fig. 6

zeigt eine Draufsicht auf ein opakes optisches Element für das Sicherheitsdokument nach Fig. 5.

Fig. 7a bis Fig. 7c

zeigen schematische Darstellungen zur Verdeutlichung eines transparenten optischen Elements für das Sicherheitsdokument nach Fig. 5.

In the following the invention will be explained by way of example with reference to several embodiments with the aid of the accompanying drawings.

Fig. 1

shows a schematic representation of different viewing situations of a security document according to the invention.

Fig. 2

shows a sectional view of a transparent optical element for a security document according to the invention Fig. 1 ,

Fig. 3

shows a sectional view of an opaque optical element for a security document according to the invention Fig. 1 ,

Fig. 4a

shows a schematic representation of a relief structure for the optical element Fig. 2 ,

Fig. 4b

shows a schematic representation of another relief structure for the optical element after Fig. 2 ,

Fig. 4c

shows a top view of a relief structure for the optical element after Fig. 2 ,

Fig. 5

shows a schematic representation of different viewing situations of a security document according to the invention for a further embodiment of the invention.

Fig. 6

shows a top view of an opaque optical element for the security document after Fig. 5 ,

Fig. 7a to Fig. 7c

show schematic representations to illustrate a transparent optical element for the security document after Fig. 5 ,

Fig. 1 shows a security document 1 in different viewing situations 41, 42 and 43.

The security document 1 is a value document, for example a banknote or a check. Furthermore, it is also possible that the security document 1 forms an identification document, for example an identity card.

The security document 1 consists of a flexible carrier 17, on which a transparent optical element 18 is arranged in a region 11 and an opaque optical element 19 in a region 12. The carrier 17 is preferably a carrier made of paper material, which is provided with an imprint and in which further security features, for example watermarks or security threads, are introduced.

However, it is also possible that the carrier 17 is a plastic film or a laminate consisting of one or more paper and plastic layers.

In the area 11, a window-shaped opening, for example by punching, is introduced into the carrier 17, which is then closed again by applying the transparent optical element 18. Thus, the security document 1 in the area 11 has a transparent window with the transparent optical element 18.

However, it is also possible that a transparent or partially transparent material is already used as the material for the carrier 17 and the carrier can thus remain in the region 11. This is the case, for example, if the carrier 17 consists of a transparent plastic film, which in the area 11 not provided with a haze layer. Furthermore, it is also possible to produce the transparent window already in papermaking and to introduce the transparent optical element 18 into the carrier 17 in the manner of a security thread.

As in Fig. 1 1, on the side of the security document 1 opposite the region 11, a patch 13 is applied to the carrier 17, on which the opaque optical element 19 is arranged. The patch 13 is preferably the transfer layer of a transfer film, for example a hot stamping foil, which is bonded to the carrier 17 under the action of pressure and heat by means of an adhesive layer. As in Fig. 1 In addition to the optical element 12, the patch 13 may also have one or more further optical elements 14 and 16, which, as in the region 15, may form a combination representation with the optical element 19. The optical elements 14 and 16 is, for example, diffraction gratings, holograms, Kinegrams ^® or with effect pigments indica executed.

Furthermore, it is also possible for the transparent optical element 18 and the opaque optical element 19 to be arranged on two different sheets of a security document, for example a passport, which are joined together, for example by stitching or gluing.

The detailed structure of the optical element 18 will now be described with reference to FIGS Fig. 2 . Fig. 4a, Fig. 4b and Fig. 4c explained.

Fig. 2 shows the carrier 17, which consists of a paper material of a thickness of about 100 microns and in the region 11 has an opening produced by means of a punching or cutting operation. The optical element 18 is preferably applied under heat and pressure to the paper material of the carrier 17, in which an adhesive layer of the optical element 18 is activated by heat and pressure. Due to the pressure exerted at the same time Area of the optical element 18, the in Fig. 2 created depression created.

The optical element 18 consists of a carrier film 181, an adhesion-promoting layer 182, a replication lacquer layer 183, an optical separation layer 184 and an adhesive layer 186.

The carrier film 181 consists, for example, of a PET or BOPP film with a layer thickness of 10 to 50 μm. The function of the carrier film 181 is to provide the necessary stability for bridging the aperture. The primer layer 182 has a thickness of 0.2 to 2 μm and is applied to the carrier film by a printing method. The replication lacquer layer 183 is made of a thermoplastic or crosslinked polymer into which a relief structure 185 is replicated by means of a replication tool under the action of heat and pressure or by UV replication. The optical separation layer 184 has a sufficiently large refractive index difference (eg, 0.2) from the replication resist layer 183 and is on the surface opposite the relief structure, as in FIG Fig. 2 indicated, largely planar.

The optical separating layer 184 can also be omitted here. Furthermore, it is also possible for the adhesive layer 186 to be omitted in the area of the relief structure 185 so that the relief structure 185 comes into direct contact with the air.

The relief structure 185 is preferably not a relief structure forming a refractive lens, but rather a diffractive relief structure which produces the effect of a convex lens by means of diffraction optics. Diffractive relief structures which can be used for this purpose consist of lattice structures that are continuously changed over the surface area with regard to their grid frequency and, if appropriate, further lattice constants, as shown, for example, in FIGS Fig. 4a and Fig. 4b are shown.

Fig. 4a FIG. 4 shows the relief structure 185 formed between the replication lacquer layer 183 and the optical separation layer 184, in each case one flank 65 the grid grooves are parallel to one another, while the angle 67 of the other side 64 changes substantially continuously with respect to a vertical main plane of the separating layer over the surface area. Arranged in the center of the lens is a paraboloid-shaped section 66 from which both the grating frequency and the angle 67 of the flank 64, as in FIG Fig. 4c clarifies, continuously changes.

Fig. 4b FIG. 5 shows a binary relief structure 187 formed between the replication lacquer layer 183 and the optical separation layer 184, which also diffractively produces the effect of a convex lens. The advantage of using such a binary relief structure compared to that in Fig. 4a In this case, the relief structure shown or a sinusoidal relief structure consists in that the profile depth 68 necessary for the generation of the lens effect can be reduced.

In the in the figures Fig. 4a and Fig. 4b The values of the relief depth indicated are the phase difference in radians, from which the geometrical depth of the relief structure can be calculated in a known manner as a function of the wavelength of the light used (eg of 500 nm for the maximum sensitivity of the human eye). The diameter of the lens structure is generally between 0.5 and 300 mm, the focal length of the lenses usually being between the value of the lens diameter and five times this value.

The detailed structure of the optical element 19 will now be described with reference to FIG Fig. 3 clarified.

Fig. 3 shows the carrier 17 and the patch 13, which forms the optical element 19 in the region 12. In this case, the patch 13 has an adhesive layer 131, a reflection layer 132, a replication lacquer layer 134, a pattern-shaped decorative layer 135 and a protective lacquer layer 135. In the boundary layer between the replication lacquer layer 134 and the reflective layer 131, a relief structure 136 is formed in the area 12.

The reflection layer 132 is preferably a thin, vapor-deposited metal layer or an HRI layer (HRI = High Refraction Index). Suitable materials for an HRI layer are, for example, TiO ₂ , ZnS or Nb ₂ O ₅ . As the material for the metal layer is substantially chromium, aluminum, copper, iron, nickel, silver, gold or an alloy with these materials in question. The reflectivity could also be achieved with an encapsulated system (two suitable materials with a sufficiently large difference in refractive index) to air. Further, instead of such a metallic or dielectric reflection layer, a thin-film layer sequence having a plurality of dielectric or dielectric and metallic layers may be used.

The relief structure 136 between the replication lacquer layer 134 and the reflective layer 132 forms a concave mirror element. The relief structure 136 is preferably not a macrostructure forming a refractive concave mirror element but a diffractive relief structure which produces the effect of a concave mirror element by means of diffraction optics. With regard to the relief structures which can be used for this purpose, reference is made to the comments on the figures Fig. 4a to Fig. 4c referenced, wherein the usable for this purpose relief structures mirror-symmetrical to the reference to the figures Fig. 4a to 4c formed relief structures, wherein the grid frequency increases continuously from the center of the concave mirror element, but the curvature has a reverse sign.

The relief structure 136 is formed in the present exemplary embodiment by a relief structure which is formed from an additive superimposition of a structure that produces the effect of a concave mirror element and another optical pattern-generating diffractive structure analogously to the relief structures 185 and 187. This diffractive structure is, for example, a hologram in the form of a Swiss cross.

The decorative layer 135 is preferably patterned according to a micro-pattern which is just below the resolution of the human eye lies. In the present exemplary embodiment, the decorative layer 135 is structured in the form of the number "100". It is advantageous here that the micropattern is a repetitive micropattern which is composed of a large number of identical structural elements. For example, each of these structural elements is formed from a representation of the number "100". In this case, it is also possible that the surface density of the structural element is varied in the form of a gray-scale image and thus contains further image information that is immediately recognizable to the human eye.

The decorative layer preferably stands on a print applied by means of a printing process and may consist of a transparent colored layer, or of a layer containing interference-dye pigments or cholesteric liquid-crystal pigments, which produces an optically variable color impression. Furthermore, it is also possible to use as a decorative layer a thin-film layer system for producing viewing angle-dependent color shifts by means of interference, in which case the decorative layer is preferably arranged between the replication lacquer layer 134 and the reflection layer 132. Another possibility is not to continuously apply the reflection layer 132 to the replication lacquer layer 134, but instead to pattern it pattern-like, preferably pattern-shaped as described above according to a micropattern. After the reflection layer 132 has been applied over the whole area, the reflection layer 132 is partially demetallised by positive / negative etching or partially removed by means of laser ablation.

• Bei einem Abstand 24 zwischen den sich überdeckenden optischen Elementen 18 und 19 zeigt sich ein optischer Effekt 52 in Form einer holographischen Darstellung eines schweizer Kreuzes im Hintergrund zu einer Darstellung der Zahl "100". Bei einem größeren Abstand 22 zwischen den sich überdeckenden optischen Elementen 18 und 19 zeigt sich ein optischer Effekt 51 in Form einer gegenüber dem optischen Effekt 52 deutlich vergrößerten Darstellung der Zahl "100" vor der holographischen Darstellung des schweizer Kreuzes. Befinden sich die optischen Element 18 und 19 nicht in Überdeckung, zeigt sich als optischer Effekt ein Graustufenbild, welches in die Strukturierung der Dekorschicht 135 codiert ist.

As a result of the configuration of the security document 1 as described above, the security document 1 exhibits the following optical effects in the viewing situations 41, 42 and 43:

• At a distance 24 between the overlapping optical elements 18 and 19, an optical effect 52 in the form of a holographic representation of a Swiss cross in the background appears to represent the figure "100". At a greater distance 22 between the overlapping optical elements 18 and 19, an optical effect 51 is shown in the form of a comparison with the optical effect 52 significantly enlarged representation of the number "100" in front of the holographic representation of the Swiss Cross. If the optical elements 18 and 19 are not coincident, a grayscale image, which is coded into the structuring of the decorative layer 135, appears as an optical effect.

Based on Fig. 5 Now, another embodiment of the invention will be explained.

Fig. 5 1 shows a security document 7 which has an opaque optical element 73 in a region 71 and a transparent optical element 74 in a region 72. The optical elements 73 and 74 are in this case applied to a carrier 75. In a viewing situation 44, the optical elements 73 and 74 are not in registration, in a viewing situation 45, the optical elements 73 and 74 are spaced apart by a distance 25 and spaced in a viewing situation 46 with a smaller distance 26.

The optical element 73 has a layer patterned in accordance with a micropattern and thus consists, for example, of a protective lacquer layer, a decorative layer structured in accordance with the micropattern, and an adhesive layer. The decorative layer consists for example of a color layer, an effect pigment layer or a reflective layer, which is structured by corresponding pattern-shaped imprint, by positive / negative etching or by ablation in the form of the micropattern. So shows, for example Fig. 6 an enlarged plan view of the optical element 73, which shows one of a plurality of similar, repetitive structural elements 76 in the form of the letter "A" formed micro-pattern. As already described above, it is possible for the structural elements 76 to be arranged on the optical element 73 in a different surface density, so that further information, which is directly recognizable to the human eye, is coded into the micropattern in the manner of a gray scale image. As a structural element, micrographs, microimages or entire microtext passages can also be used. Furthermore, it is also possible that the Micro-pattern is composed of differing structural elements.

Further, it is also possible that the optical element 73 as the optical element 19 after Fig. 3 is constructed, with the difference that the diffractive structure 136 is not acted upon by the additive superposition of a diffractive optical a concave mirror element generating structure. The diffractive structure formed in the optical element 73 between the replication lacquer layer and the reflection layer is preferably a background hologram, which is also visible in the viewing situation 44. According to another preferred embodiment, the diffractive structure, for. As a black mirror structure, provided in accordance with a micropattern shaped pattern areas, for example in the area covered by the structural element 76 areas. In the background area, in this case, a second, differently diffractive structure, for. As a matt structure may be provided.

The optical element 74 is like the optical element 18 according to the figures Fig. 1 . Fig. 2 and Fig. 4a to Fig. 4c with the difference that the relief structure 185 corresponds to a grid of a convex lens having a focal length corresponding to the distance 25 with a lenticular pattern matched to the micropattern of the optical element 73 having a plurality of micro-lenses of a focal length corresponding to the focal length Distance 26 corresponds.

The relief structure 185 thus has, for example, a 60 μm / 60 μm grid of a macroscopic list with a microlens grid. The macroscopic lens has a diameter in the range of 3 mm to 50 mm, preferably 10 mm to 30 mm. The focal length of the lens is between half the diameter and ten times the diameter, preferably between the simple diameter to five times the diameter. For example, the macroscopic lens has a diameter of 25 mm and a focal length of 75 mm. The microlens grid consists of microlenses with a diameter in the range of 5 .mu.m to 500 .mu.m, preferably between 50 .mu.m and 200 μm. The focal length of the microlenses is between half the diameter and one hundred times the diameter, preferably between one to ten times the diameter. For example, the diameter of the microlenses is 150 μm at 1 mm focal length.

• Wie in Fig. 7a gezeigt, ist der Flächenbereich des optischen Elements 74 in erste Bereiche 77 und zweite Bereiche 78 unterteilt, die jeweils benachbart zueinander angeordnet sind. Die Breite der ersten und zweiten Bereiche 77 und 78 liegt hierbei unterhalb des Auflösungsvermögens des menschlichen Auges, so dass der Abstand zwischen zwei ersten oder zwei zweiten Bereichen beispielsweise < 200 µm beträgt.

The FIGS. 7a to 7c illustrate several embodiments of such a superposition of a convex lens and a microlens raster:

• As in Fig. 7a As shown, the area of the optical element 74 is divided into first areas 77 and second areas 78, which are respectively disposed adjacent to each other. The width of the first and second regions 77 and 78 is below the resolution of the human eye, so that the distance between two first or two second regions is, for example, <200 μm.

In the areas 77, the micro-lenses of the micro-lens grid are arranged. The micro-lenses are in this case preferably designed as refractive lenses, but it is also possible that these lenses analogous to the embodiments of Fig. 4a to Fig. 4c are designed as a "diffractive" lens. Next is a convex lens forming diffractive relief structure according to the figures Fig. 4a to Fig. 4c arranged distributed over the surface areas 78 on the surface area of the optical element 73.

In an area 80 after Fig. 7b For example, first regions 81 and second regions 82 are arranged alternately next to one another, here too, the distance between two first regions 81 and two second regions 82 being below the resolving power of the human eye.

In an area 83 after Fig. 7c first surface regions 84 and second surface regions 85 are arranged next to one another next to one another, in which case only a single convex lens of the lens raster is arranged in the first surface regions 84, which is then preferably realized as a "diffractive" lens.

• In der Betrachtungssituation 45 wird dem Betrachter eine vergrößerte Darstellung eines oder mehrerer Strukturelemente 76 als optischer Effekt gezeigt. In der Betrachtungssituation 46 zeigt sich dem Betrachter eine Information, die in der relativen Position des Mikromusters oder Teilen des Mikromusters zu dem Linsen-Raster codiert ist. Innerhalb der Betrachtungssituation 44 zeigt sich als optischer Effekt das in die Gestaltung des Mikromusters des optischen Elements 73 codierte Graustufenbild oder ein Hologramm oder ein sonstiges beugungsoptisch generiertes Muster, beispielsweise ein KINEGRAM^®, das sich aus der Überlagerung der von den in den Musterbereichen abgeformten diffraktiven Strukturen erzeugten optischen Effekte ergibt.

In the viewing situation 44 to 46, the viewer thus has the following visual effects:

• In the viewing situation 45, the viewer is shown an enlarged representation of one or more structural elements 76 as an optical effect. In the viewing situation 46, the viewer is presented with information encoded in the relative position of the micropattern or parts of the micropattern to the lens raster. Within the viewing situation 44 is shown as an optical effect, in the configuration of the micropattern of the optical element 73 coded greyscale image or a hologram or other diffraction-optically generated patterns, for example a KINEGRAM ^®, which results from the superposition of the diffractive from molded in the pattern regions structures generated optical effects.

Furthermore, it is also possible that instead of a microlens grid in the areas 77, 81 and 84 according to FIGS Fig. 7a to Fig. 7c of the optical element 74 structures of a moire analyzer are arranged and instead of the micro-pattern after Fig. 6 a moiré pattern is disposed in the optical element 73.

A moiré pattern here is a pattern formed from repetitive structures which, when superimposed with or viewed through another pattern formed by repetitive structures acting as a moiré analyzer, forms a new pattern, namely a moire pattern. Image shows hidden in the Moire pattern. In the simplest case, this moiré effect results from the superimposition of dark and light stripes, which are arranged according to a line grid, this line raster being partially phase-shifted in order to produce the moire image. In addition to a linear line grid, it is also possible that the lines of the line grid have curved areas and are arranged, for example, wave-like or circular. Furthermore, it is also possible to construct a line grid twisted or overlaid against each other in two or more directions Moire pattern to use. The decoding of the moiré image in such a line raster is likewise effected by a region-wise phase shift of the line raster, whereby two or more different moiré images can be encoded in such a moiré pattern. Furthermore, the use of Moire patterns and Moire analyzers is possible, which are based on the so-called "Scrambled Indicia ^® technology" or on a hole pattern (round, oval, square holes of various design).

The moiré analyzer arranged in the regions 77, 82 and 84 thus consists, for example, of an opaque stripe pattern. The moiré pattern provided in the optical element 74 may be as described with respect to the micropattern Fig. 6 be implemented as a patterned decorative layer or in a molded in pattern areas diffractive structure. The moire pattern is hereby substructured, whereby this substructuring preferably takes place in the form of a microtext or of repeating microimages.

If the optical elements 74 and 73 overlap one another when overlapped, i. When the distance between the optical elements 73 and 74 is very small, the moiré image generated by the superimposition of the moiré pattern and moire analyzer becomes apparent. If the distance is increased, the observer will see the magnified representation of the microstructuring of the moiré pattern, that is, for example, an enlarged and thus readable representation of a microtext. If the optical elements 73 and 74 do not overlap, then the optical effects already described in relation to the viewing situation 44 are shown.

Claims (13)

1. Security document (1, 7), in particular banknote or passport, with a first transparent region (11, 72) in which a first transparent optical element (18, 74) is arranged, and with a second region (12, 71) in which a second opaque optical element (19, 73), which exhibits a first optical effect, is arranged, wherein the first region (11, 72) and the second region (12, 71) are arranged on a carrier (17, 75) of the security document and are spaced apart from one another such that the first and the second regions can be made to overlap, characterized in that the first optical element (18, 74) and the second optical element (19, 73) are designed, and matched to one another, such that when the second optical element and the first optical element are made to overlap, with a first spacing (24, 26) between the first and the second optical elements, a second optical effect (52) becomes visible, and when the second optical element and the first optical element are made to overlap, with a second spacing (22, 25) between the first and the second optical elements, with the second spacing being larger than the first spacing, a third optical effect (51), which differs from the second optical effect, becomes visible, with the second optical element exhibiting a micropatterned Moiré pattern and the first optical element having an at least partially transparent layer in which a Moiré analyser, which is matched to the Moiré pattern, and a convex lens are superposed, with the convex lens having a focal length which corresponds to the second spacing and being suitable for rendering the micropatterning of the Moiré pattern visible.
2. Security document (1, 7), in particular banknote or passport, with a first transparent region (11, 72) in which a first transparent optical element (18, 74) is arranged, and with a second region (12, 71) in which a second opaque optical element (19, 73), which exhibits a first optical effect, is arranged, wherein the first region (11, 72) and the second region (12, 71) are arranged on a carrier (17, 75) of the security document and are spaced apart from one another such that the first and the second regions can be made to overlap, characterized in that the first optical element (18, 74) and the second optical element (19, 73) are designed, and matched to one another, such that when the second optical element and the first optical element are made to overlap, with a first spacing (24, 26) between the first and the second optical elements, a second optical effect (52) becomes visible, and when the second optical element and the first optical element are made to overlap, with a second spacing (22, 25) between the first and the second optical elements, with the second spacing being larger than the first spacing, a third optical effect (51), which differs from the second optical effect, becomes visible, wherein the second optical element (73) has a layer which is patterned according to a micropattern and the first optical element (74, 2) has a transparent layer in which a grating of a convex lens with a focal length which corresponds to the second spacing (25) is superimposed with a lens grating which is matched to the micropattern and has a large number of microlenses (79, 82, 84) with a focal length which corresponds to the first spacing (26).
3. Security document according to Claim 1 or 2, characterized in that, when the second optical element and the first optical element are made to overlap, with the first spacing (24, 26), a first pattern becomes visible as a second optical effect (52) and, when the second optical element and the first optical element are made to overlap, with the second spacing (22, 25), an enlarged representation of the first pattern becomes visible as a third optical effect (51).
4. Security document according to Claim 3, characterized in that the first pattern is a diffractive pattern.
5. Security document according to one of Claims 2 to 4, characterized in that the micropattern has a typical size of less than 200 µm.
6. Security document according to one of Claims 2 to 4, characterized in that the micropattern is a pattern which is formed from a large number of the same repeating structural elements (76), with the dimensions of the individual structural elements being < 200 µm.
7. Security document according to one of Claims 2 to 6, characterized in that, in a pattern region which is formed according to the micropattern, a diffractive structure is impressed in the first layer.
8. Security document according to one of Claims 2 to 7, characterized in that the first layer is a colour layer or a reflective layer which is patterned according to the micropattern.
9. Security document according to one of Claims 2 to 8, characterized in that the convex lens is formed from a diffractive structure which produces, in an optically diffractive manner, the effect of a convex lens.
10. Security document according to one of Claims 2 to 9, characterized in that the first optical element (74) has a large number of neighbouring first and second regions, wherein the width and/or the length of the first and second regions is in each case < 200 µm and, in the first region, in each case one or more microlenses (79, 82) of the microlens grating and, in the second regions, structures (78, 81, 85) forming convex lenses are impressed.
11. Security document according to Claim 1, characterized in that the micropattern, enlarged by way of the convex lens, shows an enlarged representation of the Moiré image which is produced by the superposition of the Moiré pattern and of the Moiré analyser.
12. Security document according to one of the preceding claims, characterized in that the second optical element has a replicating lacquer layer and a reflective layer which adjoins the replicating lacquer layer and a diffractive relief structure, which shows the first optical effect when viewed directly, is impressed into the boundary surface between replicating lacquer layer and reflective layer.
13. Security document according to one of the preceding claims, characterized in that the second optical element comprises a transfer layer of a transfer film, in particular a hot-embossing film.

Images