DE102013225516B4 - Security document with hidden security feature - Google Patents

Abstract

A security document (30) comprising a region (20) in which a first printing information (21) and a second printing information (22) are stored, which produce an identical color impression under given environmental conditions, so that under the given environmental conditions a homogeneous uniform color impression for the first printing information (21) and the second printing information (22) is generated in the area (20) and the first printing information (21) and the second printing information (22) are indistinguishable due to the color impression produced, the second printing information (22) being formed by means of an ink which has a structure color whose evoked color impression is changeable via excitation, wherein the structure color with which the second printing information is formed has a color impression during the application of the excitation due to an induced change of an internal structure is different from the first printing information, characterized in that the first printing information (21) is formed by means of another structure color whose evoked color impression is also changeable via the excitation, wherein the further structure color, with which the first printing information is formed, during the action of the same Excitation due to an induced change of an internal structure has a color impression different from the color impression of the second printing information, the structure color and the further structure color having colloidal particles having different diameters or sizes or alternatively or additionally the substances in which the particles are dispersed, differ in their properties.

Description

The invention relates to a security document and to a method for producing a security document which, under given ambient conditions, comprises an area which produces a uniform color impression but in which two different printing information are stored. Furthermore, the invention relates to a method for verifying such a security document.

Security documents are known in the prior art in which different information is stored in a region that can not be distinguished from one another due to the color impressions of the two printing information produced. An example of this is printing the area with the first and second printing information, which fill the area completely and are printed with metameric colors. Metameric colors are those colors that produce the same color impression on a human observer when illuminated with white light from a black body radiator, but whose spectrally resolved reflectance spectra are distinguishable when viewed under white light excitation. If the reflectance light is passed through a color filter or excitation during the observation does not take place with a continuous white light spectrum, but with a light spectrum in which certain excitation wavelengths are missing, the information printed with different metameric colors can be differentiated due to the then different color impressions.

Such a feature makes it possible to store covert information in a document which can be verified upon verification as to whether it actually exists. In addition, the content of the first and second printing information can, of course, additionally be evaluated and included in a verification decision.

Features that can be used for verification and thus provide protection against unauthorized duplication or creation, tampering or the like are referred to as security features. Documents having at least one security feature are referred to as security documents. Security documents include i.a. Identity cards, driver's licenses, identity cards, but also banknotes, postage stamps, visas as well as fake labels and packaging, tickets or similar.

On the one hand, printing inks or printing inks which contain pigments which absorb light of specific wavelengths and reflect or remit other wavelengths are known in the prior art. As a result, a color impression is caused by such a pigment. When printed on a document, the ink has a body color. The color impression depends on the color pigment itself. Conventional inks used for color printing security documents are among these inks.

However, printing inks are also known from the prior art, the color impression of which is brought about via nano- or microparticles contained in the printing ink, which are arranged aligned with one another in a crystal-like structure.

From the EP 2 463 111 are known such printing inks. There, printing inks are described which comprise in a printing medium a multiplicity of particles which are dispersed in the medium and have electrical or magnetic properties such that they align with one another in a crystal structure when an electric or magnetic field is applied. This crystal structure ensures that light of certain wavelengths can propagate only along certain directions or not at all in the crystal structure and is reflected accordingly. This causes a color impression due to the wavelength-selectively reflected light. In contrast to a body color can be spoken here of a structural color.

From the DE 10 2009 024 447 A1 For example, a security element with an optical appearance that can be changed by an external magnetic field is known. It is described that the security element has a multiplicity of microcapsules which contain a suspension of a carrier liquid and magnetic nanoparticles which reversibly form a photonic crystal in an external magnetic field in the microcapsules.

From the DE 10 2009 025 019 A1 a security feature is known for securing value documents with a plurality of microcapsules, each having a wall and in each of which a liquid medium is contained, in which a plurality of magnetic particles are distributed, which are movable in the liquid medium and their arrangement within the microcapsule is changeable by the action of a magnetic field, wherein the magnetic particles are adapted to be arranged within the microcapsule so that they form a light-diffractive structure.

From the DE 10 2009 023 928 A1 is a security element with an external one Magnetic field variable visual impression known that contains a variety of core-shell particles. It is contemplated that the core of the core-shell particles contain a magnetic fluid and a non-magnetic phase visually distinguishable from the magnetic fluid, which is movably disposed within the magnetic fluid.

The object of the invention is to specify an improved security document, a novel method for verifying a security document and a method for producing the security document, which comprise a novel security feature in which covert information can be stored.

Basic idea of the invention

The invention is based on the idea to form in a security document an area in which a first print information and a second print information are printed so that under predetermined environmental conditions, for example predetermined conditions with respect to an electric field and a magnetic field in the region of the printed area uniform color impression arises in a white light observation with light from a black body radiator. These two print information are applied with a different ink or inks. The second printing information is in this case printed with an ink or printing ink, which has a structure color whose evoked color impression is variable via excitation in such a way that a color impression of the structure color of the second printing information during the action of the excitation of the color impression of the first printing information and distinguishes the color impression that the structure color of the second printing information in the non-excited state, ie the state at predetermined environmental conditions having. A document designed in this way can then be verified by determining a uniform color impression for the first printing information and the second printing information, which is determined under given environmental conditions, for example with regard to an electric field and / or a magnetic field in the region of the area in the security document Discrimination of the first printing information and the second printing information due to the caused color impressions not possible. Thus, homogeneous uniform color-imprinting areas are found in the area. In a picture of this area, therefore, a uniform homogeneous color impression for the first printing information and the second printing information is to be determined. If the area is printed over the entire area with the first and the second color information, a color uniformly homogeneous surface can be detected under the given ambient conditions.

If the ambient conditions in the security document are changed and a further image is recorded, a change in the color impression produced occurs, at least at those points where the second printing information is applied, since the structure color with which the second printing information is formed differs below the color Excitation in the changed environmental conditions changed so that a different color impression is caused. The first print information is not changed with respect to the color impression or deviating from the second print information. When evaluating first areas and second areas are thus sought, which cause an identical color impression in the first image, but in the further figure, which is detected during the application of an excitation to change the color impression of the second printing information, cause a different color impression and the second regions in the image captured during the application of an excitation have a color impression that deviates from the color impression in the image that is detected under the given ambient conditions. If these areas are not found, the document can be classified as not genuine in a simple verification. It is important that the change of the color impression of the second printing information is caused by a structural change in the structure color and not by other effects. The color impression is thus based only on the remission and / or transmission properties of the document. A color impression caused by light emission is distinguished therefrom. The excitation of the structure color is such that it does not trigger light emission of the structure color. The structure color always acts passively in such a way that the color impression is not caused by a generation of photons, but only by the wavelength-selective light reflection and / or light transmission.

definitions

A preparation that can be used to print information is also referred to as ink or ink.

A preparation whose color impression produced in the printed state is caused by pigments which absorb and / or remit / reflect certain wavelengths of light independently of ambient conditions are referred to as body colors.

Printing preparations or printing inks or inks whose color impression in the printed state is caused by the fact that a plurality of Particles are arranged in a crystal-like regular structure, so that a light propagation of individual wavelengths through the crystal structure only in certain directions or not at all possible and this is a color impression is caused, are referred to as structural colors.

From the prior art, in particular the EP 2 463 111 A2 are known pressure preparations, which are structural colors. There are described printing formulations comprising a plurality of nano- or microparticles having electrical or magnetic properties which are arranged in an electric or magnetic field relative to each other in a crystal-like regular structure. There it is described that the crystal-like structures can be photonic crystals. A photonic crystal is a regular periodic structure that promotes or suppresses light propagation for single or multiple wavelengths due to quantum mechanical effects. This creates a color impression of the corresponding photonic crystal.

Structure colors, which have a changed color impression when excited, are also in the EP 2 463 111 A2 described. These may be configured such that the printing preparation comprises microcapsules enclosing a substrate in which a plurality of colloidal particles are arranged, which again have an electrical or magnetic property and in an electric or magnetic field relative to each other to a crystal or a Arrange crystal-like structure. There, it is described that the colloidal particles may be, for example, charged particles comprising, for example, aluminum, copper, silver, tin, titanium, tungsten, zirconium, zinc, silicon, iron, nickel, goblin or the like. The particles may further comprise a substance containing a polymer material, for example, polystyrene (PS), polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyethylene terephthalate (PET), etc. According to other embodiments, uncharged particles may have a be charged material loaded. For example, particles may be coated with organometallic oxides such as silicon oxide SiO _x , titanium oxide TiO _x , etc. But polymer material coated particles coated with ion exchange resins and many more can also be used. In the EP 2 463 111 A2 a variety of exemplary embodiments is described.

The substance in which the colloidal particles are arranged in the microcapsules may be a phase change material. This means that the material can be present in different phases, which have a different viscosity. Depending on the phase in which the substance is located, the colloidal particles dispersed therein may or may not align to a crystal structure upon external excitation. Also, it is possible that a crystal structure induced by external excitation in one phase of the substance is "frozen" by a change of the phase of the substance, so that the crystal structure is obtained even after removal / removal of the excitation for alignment of the colloidal particles remains.

In other embodiments, the viscosity of the substance in the microcapsules, in which the colloidal particles are dispersed, which arrange themselves upon application of an electric or magnetic field to a crystal structure, is always maintained.

An electrorheological fluid is a fluid whose viscosity is adjustable or controllable via an electric field strength. In a room where no electric field is applied, an electrorheological fluid has a low viscosity. Colloidal particles dispersed therein thus have high mobility. When an electric field is applied, the viscosity sharply increases, so that mobility of particles dispersed therein is greatly restricted or inhibited.

A magnetorheological fluid is a fluid whose viscosity is adjustable or controllable via a magnetic field strength. In a space where no magnetic field is applied, a magnetorheological fluid has a low viscosity. Colloidal particles dispersed therein thus have high mobility. When a magnetic field is applied, the viscosity sharply increases, so that mobility of particles dispersed therein is greatly restricted or inhibited.

Field-free is a space in which neither an electric nor a magnetic field is present. For the purposes of the objects described here, this is understood to mean the absence of an externally adjusted electrical or magnetic field. A field caused by magnetic particles or electrically charged particles intrinsically present in an article is left unattended. Similarly, the magnetic field strength caused by the earth's magnetic field is considered to be insignificant, so that a space is field-free despite the existing geomagnetic field, if no additional magnetic field is present in the room.

If the orientation of the colloidal particles is brought about only by the electric field, then the space is considered to be field-free when no electric field is present, even when, for example, a magnetic field is applied affect magenta-rheological fluid in the room in terms of its viscosity.

The same applies to the case where a magnetic field is used to align the colloidal particles and an electric field is used to control the viscosity of an electrorheological fluid. The space is field-free if there is no "outer" magnetic field with a field strength in the space that is greater than the field strength of the Earth's magnetic field.

Preferred embodiments

A security document comprises in a preferred embodiment an area in which a first print information and a second print information are stored, which produce an identical color impression under predetermined environmental conditions, so that under the given environmental conditions a homogeneous, uniform color impression for the first print information and the second print information in caused the area and the first printing information and the second printing information are indistinguishable due to the color impression caused, wherein it is provided that the second printing information is formed by an ink / ink having a structure color whose evoked color impression is variable via excitation. Under the given environmental conditions, a set of state variables such as temperature, light irradiation, viewing angle, but in particular an electric field strength, a magnetic field strength and its direction, homogeneity, possible gradients and the like understood. The advantage of a security document executed in this way is that, under the given environmental conditions, the first and second printing information are indistinguishable and thus can not be perceived separately. In particular, when the predetermined environmental conditions coincide with normal conditions, i. a temperature around the 21 ° C in a field-free space prevails, and a consideration is made in a lighting with white light of a black body radiator, the first and the second pressure information are not separately perceptible. The fact that different information exists at all can not be found in the security document under these conditions. If, on the other hand, the structure color with which the second printing information is formed is changed by an excitation, for example by generating an electric or magnetic field in the area of the security document or of the area in which the first and second printing information are stored or changes a crystal structure and this the transmission and / or remission or reflection properties of the structure color to the effect that only light of individual wavelengths or no wavelength of the visible spectral range and only in individual directions are transmitted through the crystal structure and for the other wavelengths or A reflection takes place. Those with the structure color, with which the second printing information is printed, is selected and configured such that a color impression of the second printing information differs from the color impression of the first printing information in the presence of an excitation, i. suitably changed environmental conditions, lifts off.

According to the invention, it is provided that the first printing information is formed by means of a further structure color whose evoked color impression is also changeable via the excitation, wherein the further structure color, with which the first printing information is formed, during the action of the same excitation due to an induced change of an internal structure has a color impression that is different from the color impression of the second printing information. Both pressure information are inventively formed by structural colors, but behave differently when excited. Both structural colors have colloidal particles which have different diameters or sizes, or in which, alternatively or additionally, the substances in which the particles are dispersed differ in their properties.

• - Herbeiführen der vorgegebenen Umgebungsbedingungen in dem Sicherheitsdokument und Erfassen einer ersten Abbildung;
• - Verändern der Umgebungsbedingungen in dem Sicherheitsdokument und Erfassen mindestens einer weiteren Abbildung;
• - Auswerten der ersten und der mindestens einen weiteren Abbildung, wobei das Auswerten ein Suchen nach ersten Bereichen und zweiten Bereich umfasst, welche in der ersten Abbildung einen identischen Farbeindruck hervorrufen, jedoch in der mindestens einen weiteren Abbildung einen voneinander abweichenden Farbeindruck hervorrufen und von denen die zweiten Bereiche in der mindestens einen weiteren Abbildung einen Farbeindruck aufweisen, der von dem identischen Farbeindruck der ersten und zweiten Bereiche in der ersten Abbildung verschieden ist;
• - Fällen einer Verifikationsentscheidung abhängig von der Auswertung, wobei das Sicherheitsdokument als nicht echt klassifiziert wird, wenn keine ersten und zweiten Bereiche mit den angegebenen Eigenschaften aufgefunden sind. Entsprechend kann das Dokument als echt verifiziert werden, wenn erste und zweite Bereiche mit den angegebenen Eigenschaften aufgefunden werden, ein Dokument als nicht echt klassifiziert wird, wenn erste Bereiche in der weiteren Abbildung denselben Farbeindruck hervorrufen wie in der ersten Abbildung.

A method for verifying such a security document which has a region in which a first printing information and a second printing information are stored, which produce an identical color impression under predetermined environmental conditions, so that under the given environmental conditions a homogeneous uniform color impression for the first printing information and the second Printing information is generated in the area and the first printing information and the second printing information are indistinguishable due to the color impression caused, comprising the steps:

• - Establishing the predetermined environmental conditions in the security document and capture a first image;
• - changing the environmental conditions in the security document and capturing at least one further image;
• Evaluating the first and the at least one further image, the evaluating comprising searching for first regions and second regions, which produce an identical color impression in the first image, but produce a different color impression in the at least one further image, of which the second areas in the at least one other Figure have a color impression that is different from the identical color impression of the first and second areas in the first figure;
• - Cases of a verification decision depending on the evaluation, wherein the security document is classified as not genuine, if no first and second areas are found with the specified properties. Accordingly, if first and second areas with the specified properties are found, a document is classified as being genuine if the first areas in the further image produce the same color impression as in the first image.

According to the invention, it is provided in the verification method that the changing of the ambient conditions comprises an excitation which causes a structural change in a structure color in the second printing information in the security document.

The verification method reliably makes it impossible to authenticate security documents that do not have the above-described security feature.

Such a security document can be produced by a method comprising the steps of printing on a region having a first printing information and a second printing information, which produce an identical color impression under predetermined environmental conditions, so that under the given environmental conditions a homogeneous, uniform color impression for the first Printing information and the second printing information is generated in the area and the first printing information and the second printing information are indistinguishable due to the color impression produced, wherein the first printing information is formed and the second printing information is printed by means of an ink having a structural color whose color impression over an excitation is changeable.

In a preferred embodiment, the first printing information is formed with an ink or printing ink whose color impression is determined by pigments having a body color. In this embodiment, the color impression of the first information does not change. The color impression in the first areas of all captured images is always the same regardless of the environmental conditions, i. encouraging independent.

The first printing information and the second printing information may be printed such that they are printed side by side and overlap each other at most at the edges where the surfaces printed with the different printing information or different inks are contiguous.

In other embodiments, however, it may be provided that, for example, the first printing information is printed over the entire surface in the area and the second printing information is printed in partial areas which do not cover the entire area with which the printing ink having a structural color is printed above it. The first printing information may be formed with color pigments which have a body color or by means of a further structure color.

In other embodiments, the second printing information may also first be printed over part of the area and the first printing information subsequently be printed over the entire area over the entire area. Regardless of whether the printing information or the surfaces printed therewith overlap each other, always first areas and second areas can be found which have a different color impression under changed environmental conditions. The first areas found in the verification need not necessarily cover the entire area printed in the area with the first printing information. In a variant in which the first printing information is printed with color pigments which have a body color, always first areas are found whose color impression does not change even when changing the environmental conditions. In addition, in the case of a genuine security document, second areas can be found which change their color impression when the environmental conditions change.

In a preferred embodiment, the area is a closed contiguous area which as a whole has a simple geometric structure such as a square, a rectangle, a triangle, a circle, an ellipse, a star, or the like as a base.

Preference is given to the structure color and, if present, additionally or alternatively the further structure color, such that they comprise microcapsules in which colloidal particles, for example colloidal nanoparticles, are contained, which can be aligned with one another by means of an electrical and / or a magnetic field in order to create and / or modify a crystal structure, wherein distances between the particles are decisive for the color impression of the respective structure color. Similar to color pigments, the microcapsules with the nanoparticles contained therein, which are arranged in a crystal structure under suitable environmental conditions, thus provide the color impression of the respective structure color or respective structure ink. Such microcapsules can be easily processed with a variety of chemical additives to printing inks, which provide the desired properties for printing such an ink and thus adapted to a corresponding printing process and the substrate to be printed can be tuned. In the as-printed state, the substance in the microcapsules is such that, under suitable environmental conditions, it ensures mobility of the colloidal particles contained therein to allow alignment of the colloidal particles in an electric and / or magnetic field, such that a structural change of the colloidal particles Entity is possible.

In a preferred development of the verification method, an electric field and / or a magnetic field are thus generated and / or changed in the security document when the environmental conditions change. This change must be brought about at least in the area in which the first and the second printing information are printed. The colloidal particles are preferably charged or paramagnetic. Depending on this configuration, they may be "excited" by an electric field or a magnetic field to form a crystal structure-like arrangement. Electrically charged particles align, for example, in an electric field and try to move along (positively charged particles) or (negatively charged particles) against the electric field lines. However, due to the inclusion in the microcapsule, the colloidal particles are restricted in their movement. Moreover, since the colloidal particles all have at least the same sign of charge, preferably the same charge, and repel similar charges, this repulsive force counteracts the directional force produced by the applied field. This results in the formation of a crystal lattice through the colloidal particles. The magnitude of the field strength affects the relationship between the force induced by the field and the repulsive force of the particles and, via this, an interparticle spacing in the crystal lattice, which in turn is responsible for the optical properties in the interaction with light.

The verification method thus provides that an electric field and / or a magnetic field in the security document are changed when the predetermined environmental conditions in the security document and when the environmental conditions are changed.

In one embodiment it is provided that the colloidal particles contained in the microcapsules are arranged in a crystal structure which leads to a color impression in the visible wavelength range when the microcapsules are in a field-free space, and the same by the first pressure information and the second pressure information Color impression is caused in a reflection of incident light in field-free space. In such an embodiment, the security feature realized via the printing information introduced with different inks in the one area is not verifiable and unrecognizable when the security document is viewed in field-free space. It is only when forming an electric field or magnetic field in the area of the security document that a change in the crystal structure of the colloidal particles takes place and, as a result, the change in the optical properties which change the color impression.

In a verification method is accordingly provided that when creating the predetermined environmental conditions in the security document a field-free space with respect to an electric field and / or a magnetic field is created.

In other embodiments, the microcapsules are such that the nanoparticles contained in the microcapsules are not arranged in a crystal structure which results in a color impression in the visible wavelength range when the capsules are in a field-free space.

In one embodiment, the first printing information is printed with an ink which causes a color impression in the visible wavelength range under the given ambient conditions. The predetermined environmental conditions are associated with a specific predetermined electrical and / or magnetic field, which causes an identical color impression in the structure color of the second printing information. Accordingly, in the verification of such a security document, a predetermined electric and / or magnetic field is generated in the one region when the predetermined environmental conditions are established. Compared to these predetermined ambient conditions, a change is then carried out by increasing the field strength, which then leads to a change in the crystal structure at least in the one structure color of the second printing information which produces a different color impression for the second printing information in the visible wavelength range. Magnetic field strengths to effect such changes are typically in the range of 5 mT to 30 mT.

In one embodiment, it is provided that a document body of the security document has at least two electrodes and the second pressure information between the at least two Electrodes is arranged. This makes it particularly easy to form an electric field in the area where the second printing information is printed. Preferably, the electrodes are connected to contacts which are led to one or different surfaces of the document body in order to form the electric field between the electrodes by applying a voltage to the contacts.

In a further development or alternative embodiment of the security document, additionally / alternatively, a coil structure may be formed in the document body, which encloses, for example, the area in which the first and second printing information are printed. The terminals of the coil may again be routed to contacts on one or several surfaces, so that a current can be fed into the coil via the contacts, which generates a magnetic field in the area in which the first and second printing information are printed.

A verification process may have further improvements. In one embodiment it is provided that, in addition, changes in the ambient conditions are made and additional mappings are recorded and evaluated with the first and the at least one further mapping, and the evaluation of the additional mappings additionally searches for each of the additional mappings a search of first regions which their Do not change the color impression with respect to the first image, and include second regions which in the first image produce the same color impression as the first regions, but produce a different color impression in the respective additional image, and a document is classified as non-genuine when the verification decision is made , If not found in at least one of the additional illustrations also first areas that do not change their color impression compared to the first figure, and second areas, which in the at least one of the additional images has a color impression that is different from the color impression of these second regions in the first illustration.

If this embodiment is further developed, then the second regions of the further image and the at least one additional image in which second regions are found can be evaluated with regard to the color impressions and it can be checked whether these differ between the additional image and the additional image. If these do not differ despite changes in the environmental conditions, the document can be classified as non-genuine. However, if the color change corresponds to an expected color change, then the document can be classified as genuine.

In embodiments in which the first print information is printed with the further structure color, this evaluation can also be applied additionally or alternatively to the expected color changes of the first regions under the different environmental conditions. Here, in the further illustration and, if appropriate, the additional images, first regions are sought which differ in terms of their color impression from that of the second regions in the respective image and the color impression in the first image.

In another development or in another alternative embodiment, it is provided that during the evaluation it is checked whether the found second regions of the at least one further image spatially coincide with found second regions of the additional mapping and if a document is classified as not genuine when the verification decision is made if the second regions of the at least one further image and the at least one additional image do not coincide spatially. As a result, verification security can be further increased. In addition, such an effect, for example, by a trailing security feature, which has an electroluminescence, not easily replicable.

The verification can be further improved by pattern recognition being performed for detected second regions, information being derived therefrom and the derived information being compared with predetermined information and when the verification decision is made classifying a document as non-genuine if the derived Information does not match the given information. If a match is reached, a positive verification decision can also be made. The derivation of information can be, for example, that the pattern recognition alphanumeric characters are determined, which are represented by the second printing information and these alphanumeric characters are compared with predetermined alphanumeric characters. In the pattern recognition but also geometric figures such as circles, triangles, diamonds, trapezoids or the like can be derived as information content.

In a further embodiment, alternatively or additionally, the color impression or the color impressions of the found second regions may be compared with expected color impressions, and in the case of the verification decision, a document may be classified as not genuine if the color impressions of the one or more second areas do not match within the given tolerances with the expected color impressions. For example, a detected color gradient can be compared to an expected color gradient as the electrical or magnetic field strength increases. If the first print information is printed with the further structure color, an analog evaluation for the first areas can be carried out.

An even higher level of verification protection is obtained with an embodiment in which the substance or substances contained in the microcapsules can or may assume different phase states, which have a different viscosity or bring about a different mobility of the colloidal particles. For example, in one embodiment it is provided that the microcapsules contain a substance which changes its viscosity depending on an internal energy. The person skilled in the art knows substances which, for example, significantly increase their viscosity when the internal energy is increased. These include, for example, electrorheological and magnetorheological fluids. In other substances takes place a temperature-dependent phase transition from a solid phase to a liquid phase at a melting or solidification temperature, which is for example in the temperature range of 35 ° C to 50 ° C. The colloidal particles are then immobile in normal ambient temperatures in the range of about 21 ° C in the substance and are "held" by this. In such an embodiment, even when an electric or magnetic field is applied, the colloidal particles are invariable with respect to their mutual orientation, so that neither a crystal structure can be induced nor changed. This makes it possible, for example, to "store" a particular color impression corresponding to a certain field strength prevailing in the microcapsule, when the phase transition from the low viscosity in the liquid state to the high viscosity in the state of solid state has taken place. Accordingly, a verification which causes a color change by changing the electric or magnetic field is only successful if, for example, the temperature of the security document in the area is increased, for example. In the case of an electrorheological fluid, a change in the crystal structure is possible only in spite of a change in the orientation of the magnetic field, provided that no external electric field exists in the microcapsules. Correspondingly, in the case of a magnetorheological fluid, an alignment can only be achieved via an electric field if there is no magnetic field, i. E. a sufficiently high magnetic field prevents a rearrangement of the colloidal particles in an electric field.

An embodiment of the verification method thus provides that when the predetermined ambient conditions are brought about, a temperature of the security document above a predetermined melting temperature of the substance in the microcapsules is brought about or maintained. Other embodiments may provide that upon establishing the environmental conditions and changing the environmental conditions, first the ambient electrical and magnetic field conditions are set and varied as predetermined but a temperature of the security document is maintained below a melting temperature of the substance in the microcapsules and a first set of Mapped images, comprising the first image and the at least one further image or the first image, which includes at least one further and the additional images that are detected and evaluated at the temperature below the temperature threshold, and then in the security document a temperature above the Melting temperature of the substance in the microcapsules is brought about and the induction and variation of the environmental conditions with respect to the electric and / or magnetic field are carried out again and erne a set of images is captured comprising a first image and the at least one further image or image, at least one other image, and additional mappings captured and evaluated analogously to the first set of images, and when the verification decision is made the security document is verified to be non-genuine if first and second regions are identifiable in the images of the first set of images and a document is also classified as non-genuine, though no first and second regions are found in the first set of images, however In the evaluation of the second set of images, a result is produced which, in the evaluation of only one set of images at an indicated temperature, would result in rating the security document as non-genuine. Below the predetermined temperature threshold, therefore, no color-changing effect may be found. Above the temperature threshold, however, all the above-mentioned different verification steps, if executed, would have to be successful in order not to lead to classification and classification as a non-genuine security document.

It is understood that only such verification steps must be successful, which make sense for the security document. Is at one In the case of a genuine security document, if the first printing information is filled in by means of pigments which have a body color, verification steps which check a change in the color impression of the first areas can not be successful.

If the first printing information is printed with the further structure color, a substance in the microcapsules which has an approximately identical melting temperature or approximately the same phase transition condition must also be selected here. The two imaging series should be recorded once for a temperature below both melting temperatures and once for a temperature above both melting temperatures.

Similarly, a verification method may be configured when an electrorheological fluid or a magnetorheological fluid is used as a substance in the microcapsules. The field clearance with respect to an electric field in an electrorheological fluid and the field clearance with respect to a magnetic field in a magnetorheological fluid correspond to the liquid phase in the above example.

Thus, one embodiment of the verification method envisages that when the environmental conditions are changed and the environmental conditions are changed on the one hand the ambient conditions with respect to the electric or magnetic field used to change the color impression of the structure color are set and varied as predetermined, but one physical parameter of the Environmental conditions in the security document are set such that a substance in which colloidal particles are dispersed which imprint a color impression of the structure color through alignment with each other in a crystal-like structure inhibits or greatly restricts mobility of these particles, and a first set of figures, the first image and the at least one further image or the first image, which comprises at least one further image and the additional images, is detected and evaluated, and on the other hand the physi is adjusted according to the predetermined environmental conditions in the security document, so that the mobility of the substance dispersed colloidal particles, which are characterized by an alignment with one another in the crystal-like structure the color impression of the structure color given for a rearrangement and alignment, and the inducing and Varying the environmental conditions with respect to the electric or magnetic field used to change the color impression of the structure color are also carried out and a second set of images comprising a first image and the at least one further image or a first image, at least one more The illustration and additional mappings are captured and evaluated analogously to the first set of mappings, and when the verification decision is made, the security document is not verified as genuine if shown in the illustrations of the first sentence of Figures first and second areas can be determined, and a document is also classified as not genuine, although in the first set of images no first and second areas are found, however, in the evaluation of the second set of images a result is found, which in the Evaluation of only a set of images in a choice of the physical parameter according to the given environmental conditions would lead to a classification of the security document as not real.

• 1a-1c schematisch eine Mikrokapsel mit darin enthaltenen koilloidalen Nanoteilchen nach einer ersten Ausführungsform im feldfreien Raum ( 1a), bei niedriger Feldstärke (1b) und bei höherer Feldstärke (1c);
• 2a-2c schematisch eine weitere Mirkokapsel in einer anderen Ausführungsform im feldfreien Raum (2a), im Raum mit geringer Feldstärke (2b) und im Raum mit höherer Feldstärke (2b);
• 3a-3f schematisch eine weitere Mikrokapsel mit darin enthaltenen kolloidalen Nanoteilchen bei einer Temperatur unterhalb einer Schmelztemperatur im feldfreien Raum (3a), mit geringer Feldstärke (3b), mit höherer Feldstärke (3c) und bei einer Temperatur oberhalb einer Schmelztemperatur im feldfreien Raum (3d), im Raum bei geringer Feldstärke (3e) und bei noch höherer Feldstärke (3f);
• 4a-4d schematische Ansichten eines Gebiets bei unterschiedlichen Feldstärken, welches mit einer ersten und mit einer zweiten Druckinformation bedruckt ist, wobei die zweite Druckinformation mit einer Strukturfarbe gedruckt ist;
• 5a-5d weitere schematische Ansichten eines Gebiets bei unterschiedlichen Feldstärken, welche mit einer ersten und einer zweiten Druckinformation bedruckt ist, wobei die zweite Druckinformation mit einer anderen Strukturfarbe bedruckt ist;
• 6a -6d weitere schematische Ansichten noch einer anderen Ausführungsform eines bedruckten Gebiets bei unterschiedlichen Feldstärken, in welches eine erste und eine zweite Druckinformation gedruckt sind, wobei die zweite Druckinformation mit einer Strukturfarbe gedruckt ist;
• 7a-7f schematische Ansichten noch eines weiteren Gebiets, in welches erste und zweite Druckinformationen verdruckt sind, wobei die zweite Druckinformation mit einer Strukturfarbe gedruckt ist, die ihre Strukturänderung bei Anregung der Eigenschaft nur bei einer Temperatur oberhalb einer Schmelztemperatur zeigt, wobei die 7a bis 7c Ansichten bei unterschiedlichen Feldstärken bei einer Temperatur unterhalb der Schmelztemperatur und 7d bis 7f entsprechende Ansichten bei der Temperatur oberhalb der Schmelztemperatur zeigen;
• 8 eine schematische Explosionszeichnung eines Sicherheitsdokuments; und
• 9a, 9b schematische Ansichten des Sicherheitsdokuments nach 8 bei unterschiedlichen Feldstärken.

The invention will be explained in more detail with reference to a drawing. Hereby show:

• 1a-1c FIG. 2 schematically shows a microcapsule with co-lateral nanoparticles contained therein in a field-free space according to a first embodiment (FIG. 1a ), at low field strength ( 1b ) and at higher field strength ( 1c );
• 2a-2c schematically another Mirkokapsel in another embodiment in the field-free space ( 2a ), in space with low field strength ( 2 B ) and in the room with higher field strength ( 2 B );
• 3a-3f schematically another microcapsule with colloidal nanoparticles contained therein at a temperature below a melting temperature in the field-free space ( 3a ), with low field strength ( 3b ), with higher field strength ( 3c ) and at a temperature above a melting temperature in the field-free space ( 3d ), in space at low field strength ( 3e ) and at even higher field strength ( 3f );
• 4a-4d schematic views of an area at different field strengths, which is printed with a first and a second printing information, wherein the second printing information is printed with a structure color;
• 5a-5d further schematic views of an area at different field strengths, which is printed with a first and a second printing information, wherein the second printing information is printed with a different structure color;
• 6a - 6d Further schematic views of yet another embodiment of a printed area at different field strengths, in which a first and a second Printing information is printed, the second printing information being printed with a texture color;
• 7a-7f schematic views of still another area in which first and second printing information are printed, wherein the second printing information is printed with a structural color that shows their structural change upon excitation of the property only at a temperature above a melting temperature, wherein the 7a to 7c Views at different field strengths at a temperature below the melting temperature and 7d to 7f show corresponding views at the temperature above the melting temperature;
• 8th a schematic exploded view of a security document; and
• 9a . 9b schematic views of the security document after 8th at different field strengths.

Based on 1a to 1c . 2a to 2c and 3a to 3f is to be explained schematically by way of example the mode of action of different structural colors, which are each microcapsules 10 contain. The same technical features are provided in the figures with the same reference numerals. A structure color contains a multiplicity of such microcapsules, which are responsible for the color impression of the structure color. The microcapsules 10 each have a shell 11 on which a transparent substance 12 containing colloidal particles, eg nanoparticles 13 , includes. The case 11 is made of a transparent material. The substrate 12 is also transparent and represents a fluid in which the nanoparticles 13 in the embodiments according to 1a to 1d . 2a to 2d can move. The nanoparticles are for example clusters of iron oxide with a charged layer or plastic nanospheres with a charged coating. In other embodiments, they may also be paramagnetic particles. With regard to concrete embodiments of both the sheaths, the substances contained therein and the nanoparticles is in particular on the EP 2 463 111 A2 directed. In addition, structural paints containing such microcapsules are also available from Nanobrick, Gyeonggi-do, Korea.

In the embodiment according to 1 the colloidal nanoparticles are arranged irregularly in field-free space. The capsules have no special optical property, so that they do not significantly influence the color impression of the structure color in which they are contained. This can thus be regarded, for example, as almost transparent in the printed state. If an electric field with a field strength E1 is applied, the charged nanoparticles align themselves to form a grid-like crystal structure 15 , Since the nanoparticles themselves carry a charge, this leads to a repulsion between them. A ratio of the electric field strength E1 to the own repulsion due to the charge determines a lattice spacing of the nanoparticles.

The crystal structure thus formed has characteristics of a photonic crystal. In these, for some wavelengths propagation is possible only along certain spatial directions. For other wavelengths, propagation may not be possible in any direction. This means that all the light of this wavelength and from all the sinks is reflected. As a result, the color of the microcapsule is conditional. In the example shown in FIG 1b For example, when illuminated with white light from a black body radiator, a red wavelength component is reflected. If the electric field strength is increased to a value E2> E1, a distance between the nanoparticles is reduced since the ratio between the force due to the external electric field and the repulsive force between the like-charged nanoparticles is given a different ratio. This changes the crystal structure so that a blue component is now reflected, for example, from the white light of a black body radiator, so that the microcapsule provides a blue color impression.

In the 2a to 2c is another version of microcapsules 10 shown schematically. These differ in that the colloidal particles are already in the field-free space in the microcapsule 10 a crystal structure 15 such that a red color component is reflected from the white light of a blackbody beam. When the field strength is increased, the distance between the particles in the crystal lattice decreases, so that now a green color component is reflected. If the field strength continues to increase ( 2c ), the grid spacing becomes even smaller, so that again a blue color component is reflected again.

In 3 Again, another embodiment of microcapsules 10 shown. In this embodiment, the substance is in the microcapsule 10 at different temperatures a significantly different viscosity. Below a melting temperature TS, mobility of the colloidal particles is severely limited, so that even with the application of a weak electric field with field strength E1 or a stronger field strength E2 (cf. 3b and 3c ) the crystal structure does not change. In this embodiment, the crystal structure is unchanged regardless of the electric field strength such that, for example, from the white light of a black body radiator red light is reflected. If, on the other hand, the temperature is set above a melting temperature, then the substance becomes liquid, so that when an electric field E1 (FIG. 3e ) or a stronger electric field E2 ( 3f ) form a crystal lattice structure, each with smaller particle spacings, so that, for example, green light is reflected at a weak electric field E1 and blue light at a stronger electric field E2.

The embodiment of the 3a to 3f is described for a substance that has a temperature-dependent phase transition. Using a magnetorheological fluid as a substance, one obtains an analogous behavior. That in connection with the 3d to 3f described behavior shows such an embodiment when full physical size temperature is used the physical size magnetic field strength, wherein a magnetic field-free space or magnetic field-free state corresponds to the situation in which the temperature is above the melting temperature. The situation of 3a to 3c occurs when a sufficiently high magnetic field is applied, so that the viscosity of the substance in the microcapsules is greatly increased.

The same applies when using an electrorheological fluid together with magnetic particles which are aligned by a magnetic field. Here, the electric field strength takes over the control of the viscosity of the electrorheological fluid and thus represents the physical quantity which is analogous to the temperature in the above example. A low electric field strength corresponds to a temperature above the melting temperature and a high electric field strength to a temperature below the melting temperature.

If one uses the described microcapsules in a printing ink, it has a so-called structure color. In 4a to 4d FIG. 4 schematically illustrates four schematic views of an area of a security document. FIG. In 4a is a legend for the mediated color impressions indicated for all 4a to 7f applies. In the area 20 are a first information 21 and a second information 22 printed. In the embodiment according to 4a to 4d are the first information 21 and the second information 22 printed side by side. The second printing information exemplarily forms the letter "A". The remaining area of the area 20 is through the first printing information 21 busy.

In this embodiment, a structural ink is used, which Mirkokapseln similar to those of 1a includes. In the field-free space, therefore, the second printing information can be recognized by the fact that the corresponding printed area is colorless or transparent. By contrast, the first printing information has, for example, a red color impression. In a weak electromagnetic field, a crystal structure is formed from the colloidal particles in the microcapsules, so that they also reflect red light. In this state, the first printing information and the second printing information are indistinguishable. These conditions are the given environmental conditions for this security document. If the electric field is increased, the particle spacing in the crystal lattice structure decreases, whereby the distance between the particles decreases with increasing field strength (cf. 4c and 4d ), so corresponding to those areas (second areas 24 ), which with the second pressure information 22 are printed, have a different color impression, namely a green or blue color impression.

In order to verify this security document, the weak field strength is first set to determine if a uniform area is created in which no first and second areas are perceptible due to the color. This is at the in 4b illustrated example of the case.

Subsequently, the electric field strength is changed and further images are detected, the schematic Fig. 4c or 4d are shown. If you look for areas that have not changed their color, these are the first areas 23 that are still red. In addition, second areas occur 24 auf, which form the letter "A", which in the 4c and 4e a different color impression compared to the same areas in the 4b exhibit. If this deviation is detected, this can be used for verification.

If you perform a pattern recognition of the second areas 24 out, so here information in the form of the letter "A" would be derived, which can then be compared with a default. If the letter "A" is expected, then a positive verification decision can be made. If another letter, for example the letter "B" is expected, but the letter "A" is derived, this would lead to a negative verification decision.

In the 5a to 5d a further embodiment is shown schematically. Shown are the views of one area of a security document for different field strengths. This embodiment differs from that according to 4a to 4d in that the whole area 20 full surface with the first printing information 21 is printed and the second printing information, which again covers an area which a Capital letters "A" over which is printed. Again, microcapsules are included, which are after those 1a to 1c same. In the field-free space, therefore, the printing ink with the microcapsules is almost transparent, so that the uniform homogeneous color impression is caused solely by the first printing information. Under the given environmental conditions, the structure color then assumes the same color impression as the first print information. This is in 5b shown. If the field strength is further increased, color changes of the second areas printed with the second print information 22 occur 24 to the green and blue on, what in the 5c and 5d is shown.

In the 6a to 6d another embodiment is shown. In this embodiment, the second printing information 22 , which is printed with the structure color, already in the field-free space, the structure color red, which is identical to the body color of the first printing information 21 is selected. In field-free space, a homogenous uniform color impression results for the entire area 20 , When the field strength increases, occurs in those areas 24 that with the second printing information 22 and corresponding ink are printed, which has a structural color, the letter "A" in different colors over green to blue out. For the verification can thus be additionally evaluated, whether in the several recorded figures Fig. 6b to 6d for environmental conditions that do not meet the predetermined environmental conditions, respectively second areas 24 are detected, which have a different color impression in the respective image to the corresponding color impression in the figure Fig. 6a, which is detected at the predetermined environmental conditions. In this case, the given ambient conditions when detecting the given. On the one hand can be evaluated, whether in the different 6b to 6d detected second areas are congruent in all figures. Likewise, it can alternatively or additionally be evaluated whether the resulting color gradient corresponds to an expected color gradient.

In the 7a to 7e an embodiment is shown in which the printing ink, which has a structural color, is similar to the microcapsules, as in connection with the 3a to 3f is explained. As long as the temperature is below the melting temperature, the area shows 20 a uniformly homogeneous color impression both in field-free space ( 7a ) as well as with increased electric field strengths ( 7b and 7c ). If, on the other hand, the temperature is raised above a melting temperature, it is true that in the field-free space a uniformly homogeneous area is again recorded with regard to the color impression. At increased field strengths ( 7e and 7f ), however, are clearly the second areas 24 , which form the letter "A" out. Here, the verification can additionally include a check whether at a temperature below a melting temperature, despite changing the electric field, no color change can be seen, above the melting temperature, however, the color change occurs when changing the electric field.

As already mentioned above, other embodiments which comprise an electrorheological or magnetorheological fluid as the substance in the microcapsules of the structural ink can be designed analogously. In place of the physical quantity temperature occurs in each case the electric field strength for an electrorheological fluid and the magnetic field strength for a magnetorheological fluid, wherein in each case a low field strength corresponds to the temperature above the melting temperature and a high field strength with the low temperature below the melting temperature. In order to align the colloidal particles, an electro-rheological fluid uses a magnetic field and, in the case of a magnetorheological fluid, an electric field analogous to the above-described case of a substance with a temperature-dependent phase transition.

In 8th schematically an exploded view of a security document is shown. The security document 30 comprises a total of five substrate layers 31-35 in the illustrated embodiment. Only the top two substrate layers 31, 32 must be designed to be transparent in order to obtain the first printing information 21 and the second printing information 22 in the area 20 to be able to recognize which is printed on the middle substrate 33. The substrate layers 32 and 34 adjoining the middle substrate layer 33 each have an electrically conductive planar or grid-like structure as the electrode 41 . 42 applied. For example, such an electrode 41 . 42 be formed transparent by means of zinc sulfite. However, it is also possible that the electrode arranged on the substrate layer 34 below the printing information 42 is formed as a metal layer or metal grid. If the grid lines are chosen fine enough, the electrode can also be used 41 can also be formed on the substrate layer 32 by means of metallic wires or opaque conductive printing structures in the form of a grid, which has a high light transmission in the range of above 50% to preferably 90% in the visible wavelength range. However, it is particularly preferable to use a transparent electrode. The electrodes 41 . 42 are contacted by the various substrate layers with contacts 51, 52 on the uppermost substrate layer 31 in the assembled state. Corresponding electrodes 53, 54 are correspondingly provided with a conductive structure in the form of a coil on the middle Substrate layer 33 contacted. This encloses the area 20 , Will a current through the conductor loop 55 Thus, a magnetic field is created in the region of region 20. Thus, particles which are paramagnetic can be aligned to a crystal structure similar to charged particles via an electric field.

The top and bottom substrate layers 31, 35 serve essentially as protective layers. All substrate layers 31, 35 are preferably joined together by a high temperature lamination process. It is understood that additional additional security features in the security document 30 can be integrated in any combination, such as security prints, holograms, other diffractive structures, electronic circuits, etc.

In 9a is a top view of the security document 30 shown in field-free space. In this embodiment, the second printing information exists 22 in a circular structure. This can not be recognized because the structure color in the field-free space has the same color impression as the pigment color, with the first print information 21 in the rest of the area 20 is printed. If, however, a voltage to the electrodes 41 . 42 created, so it forms in the area 20 between the electrodes 41 . 41 an electric field. This changes the crystal structure of the second printing information and changes its color. The second area 24 (the circle) occurs clearly opposite the first area 23 , in which the pigment color is printed out. Verification of the security document is reliable and easy. When using the 8th and 9a to 9b In the described embodiments, electrodes and a coil are present in the security document to provide field strength in the field 20 to be able to vary. Likewise, other embodiments may include only one of the two excitation options or none of these options. The electrical and / or magnetic field strength can also be produced in any other way, in a tester or simply by means of a magnet, etc.

When the substance used is a magnetorheological fluid in which the colloidal particles are dispersed, crystal structure formation or change upon variation of the electric field can be observed only in the absence of a magnetic field. Becomes a magnetic field in the area 20 generated, a phase transition takes place in the substance. The viscosity drops drastically. The same applies to magnetic colloidal particles in an electrorheological fluid. For verification, when using a magnetorheological fluid, two sets of images at different electric fields are detected and selected once without the applied magnetic field and once with the applied magnetic field. When the magnetic field is applied no color changes are observed depending on the electric field. The same applies to the use of an electrorheological fluid in permutation of electric and magnetic fields.

In the described embodiments of the description of Figures 4 to 9, it is assumed in each case that the first printing information is formed with a printing ink or printing ink which has exclusively pigments which have a body color. The individual embodiments can, however, also be configured analogously so that the first printing information is or is formed with a further structure color which has the same color impression as the one structure color with which the second printing information is printed under the given ambient conditions but with a change in the Ambient conditions shows a color change, which is different from the color change of a structure color. Deviations of these alternative embodiments occur only in the sense that the first areas in the further illustration and, if necessary, if additional images are or are detected, have a color impression in the additional images which differs from the color impression in the one image. Nevertheless, first and second areas can be separated from one another because, given the same environmental conditions, which are different from the given ambient conditions, they have different color impressions and, in addition, have different color changes compared to the one image which is detected under the given ambient conditions. In this one figure, which is recorded under the given environmental conditions, the two printing information are indistinguishable due to the color impression.

It is understood that only exemplary embodiments are described and a variety of modifications is possible. The features described in the individual embodiments can be combined to provide further security features with a variety of different properties.

LIST OF REFERENCE NUMBERS

10

microcapsule

11

shell

12

substance

13

colloidal particles

15

lattice structure

20

area

21

first printing information

22

second printing information

23

first area

24

second area

30

The security document

31 - 35

substrate layers

41, 42

electrodes

51 - 54

contacts

55

conductor loop

Claims (17)

Security document (30) comprising an area (20) in which a first printing information (21) and a second printing information (22) are stored, which cause an identical color impression under predetermined environmental conditions, so that under the given environmental conditions a homogeneous uniform color impression for the first Printing information (21) and the second printing information (22) in the area (20) is caused and the first printing information (21) and the second printing information (22) are indistinguishable due to the color impression caused, the second printing information (22) by means of a Ink is formed, which has a structure color whose evoked color impression is variable via an excitation, wherein the structure color with which the second pressure information is formed, has a color impression during the application of the excitation due to an induced change of an inner structure of the Color impression of the first printing information is different, characterized in that the first printing information (21) is formed by a further structure color whose evoked color impression is also changeable via the excitation, wherein the further structure color, with the first pressure information is formed during the action the same excitation due to an induced change of an inner structure has a color impression which is different from the color impression of the second printing information, the structure color and the further structure color having colloidal particles having different diameters or sizes or alternatively or additionally the substances in which the particles are dispersed differ in their properties. Security document (30) after Claim 1 , characterized in that the structural color and / or the further structural color microcapsules (10), in which colloidal particles are complied, which are aligned by means of an electric field and / or a magnetic field to each other to create a crystal structure and / or to change, wherein distances between the particles are decisive for the color impression of the respective structure color. Security document (30) after Claim 2 , characterized in that the colloidal particles are charged or paramagnetic. Security document (30) after Claim 2 or 3 , characterized in that the microcapsules (10) maintain a substance (11) which changes its viscosity depending on an internal energy. Security document according to one of Claims 2 to 4 , characterized in that the colloidal particles contained in the microcapsules are arranged in a crystal structure, which leads to a color impression in the visible wavelength range, when the microcapsules (10) are in a field-free space, and by the first pressure information (21) and by the second printing information (22) of the same color impression is caused in a Auflichtbetrachtung in field-free space. Security document (30) according to one of Claims 2 to 5 , characterized in that the colloidal particles contained in the microcapsules (11) are not arranged in a crystal structure which leads to a color impression in the visible wavelength range when the microcapsules (11) are in a field-free space. Security document (30) according to one of the preceding claims, characterized in that a document body has at least two electrodes (41, 42) and the second pressure information (22) is arranged between the at least two electrodes (41, 42). A method of verifying a security document (30) having an area (20) in which a first printing information (21) and a second printing information (22) are stored which produce an identical color impression under given environmental conditions, so that under the given environmental conditions homogeneous uniform color impression is produced for the first print information (21) and the second print information (22) in the area (20) and the first print information (21) and the second print information (22) are indistinguishable due to the color impression produced, comprising the steps : Establishing the predetermined environmental conditions in the security document (30) and capture a first image; Changing the environmental conditions in the security document (30) and capturing at least one further image; Evaluating the first and the at least one further image, wherein the evaluation comprises a search of first regions and second regions, which produce the identical color impression in the first image, but produce a different color impression in the at least one further image and of which the second Regions in the at least one other image have a color impression that is different from the identical color impression of the first and second regions in the first image; Cases of a verification decision depending on the evaluation, wherein the security document (30) is classified as not genuine, if no first and second areas are found with the specified properties, a document is classified as not genuine, if the first areas in the figure the same Produce color impression as in the first figure, characterized in that the changing of the environmental conditions comprises an excitation, which causes a structural change in a structure color in the second printing information in the security document. Verification method according to Claim 8 , characterized in that when changing the environmental conditions, an electric field and / or a magnetic field in the security document (30) is changed. Verification method according to Claim 8 or 9 , characterized in that additional changes of the environmental conditions are made and additional images are captured and evaluated with the first and the at least one further image, and the evaluation of the additional images additionally for each of the additional images a search of first areas, which contrast their color impression do not change the first image and include second regions which in the first image produce the same color impression as the first regions, but produce a different color impression in the respective additional image; and when the verification decision is made, a document (30) is classified as non-genuine, if not in at least one of the additional images also first regions which do not change their color impression from the first image and second regions exist which in the at least one of the additional ones Illustrations have a color impression that is different from the color impression of these second areas in the first figure. Verification method according to Claim 10 characterized in that, in evaluating, it is checked whether the retrieved second regions of the at least one further image spatially coincide with retrieved second regions of the additional images, and in the case of the verification decision, a document (30) is classified as non-genuine if the second regions the at least one further image and at least one of the additional images do not coincide spatially. Verification method according to one of Claims 8 to 11 , characterized in that for detected second areas a pattern recognition is made and in this case an information is derived, and the derived information is compared with a predetermined information and when the verification decision is made, a document (30) is classified as not genuine, if the derived information does not match the given information. Verification method according to one of Claims 8 to 12 , characterized in that the color impression or the color impressions of the found second areas are compared with expected color impressions and when the verification decision is made a document (30) is classified as non-genuine, if the color impressions of the second areas are not within given tolerances with the expected color impressions to match. Verification method according to one of Claims 8 to 13 characterized in that when the predetermined ambient conditions are brought about or maintained a temperature in the security document above a predetermined melting temperature, the predetermined melting temperature corresponding to the melting temperature of a substance contained in microcapsules of a structural color and / or another structural color and in the colloidal particles are dispersed, whose arrangement in a lattice-like structure causes the color impression of the structure color and / or further structure color. Verification method according to one of Claims 8 to 14 characterized in that, when the environmental conditions are brought about and the environmental conditions are changed , firstly the ambient conditions with respect to the electric or magnetic field used to change the color impression of the structure color are set and varied as predetermined, but a physical parameter of the environmental conditions in the security document (30) is adjusted so that a substance in which colloidal particles are dispersed, which are aligned with each other in a crystal-like Structure imprinting a color impression of the structure color, inhibiting or severely restricting mobility of these colloidal particles, and a first set of images comprising the first image and the at least one further image or the first image, the at least one further image and the additional images, on the other hand, the physical parameter is set according to the given environmental conditions in the security document (30), so that the mobility of colloidal particles dispersed in this substance, which form a color impression of the structure color via alignment with one another in a crystal-like structure, for rearranging or aligning, and causing and varying the environmental conditions with respect to the electric or magnetic field used to change the color impression of the structure color, are also carried out and a second A set of images comprising a first image and the at least one further image or a first image, at least one further image and additional images is acquired and evaluated analogously to the first set of images, and when the verification decision is made, the security document (30 ) is verified to be non-genuine if second regions are detectable in the images of the first set of images, and a document is also classified as non-genuine if no second regions are found in the first set of images but in the evaluation of the second Set of pictures a result is found, which would result in the evaluation of only one set of images in a choice of the physical parameter according to the given environmental conditions to a rating of the security document as not genuine. Verification method according to one of Claims 8 to 15 , characterized in that when creating the predetermined environmental conditions in the security document (30) a field-free space with respect to an electric field and / or a magnetic field is created. A method of producing a security document (30) comprising the steps of: printing a region (20) with a first printing information (21) and with second printing information (22) which produce an identical color impression under given environmental conditions, so that a homogeneous color is obtained under the given environmental conditions uniform color impression for the first print information (21) and the second print information (22) in the area (20) is caused and the first print information (21) and the second print information (22) are indistinguishable due to the color impression caused, characterized in that the first printing information (21) and the second printing information (22) are formed by means of different inks and the second printing information (22) is printed by means of an ink which has a structure color whose evoked color impression is changeable via an excitation, wherein the excitation does not emit light causes the structure of the color, characterized in that the first pressure information is formed by a further structure color whose evoked color impression is also changeable via the excitation, wherein the further structure color with which the first pressure information is formed, during the action of the same excitation due to an evoked Change of an internal structure has a color impression, which is different from the color impression of the second printing information, wherein the structure color and the further structure color colloidal particles having different diameters or sizes or alternatively or additionally, the substances in which the particles are dispersed, differ in their properties.

Images