EP3079920B1 - Superposed security element and verification method - Google Patents

Description

The invention relates generally to an overlay security feature and element in which an optical effect occurs in the superposition of two separately formed components, and to a method of verifying such a security element.

Security features and security elements are known from the prior art, which comprise two components, which are arranged on the same component or two interconnected components of an object. The components are designed in such a way that, when the two components are superimposed in two, a special optical effect can be observed. For example, the one component can be embodied as imaging optics with which information stored in the second component can be perceived altered in the superimposition. The first component may be, for example, a magnifying glass, which makes miniaturized printed information of the second component easier to detect. In other embodiments, the one component comprises a lens array, for example a lenticular lens array, which, when properly superimposed over the second component of printed information from different viewing directions, identifies different graphical information.

From the EP 2 463 111 For example, printing inks are known whose color impression is brought about by means of microparticles contained in one color, which are aligned with one another and arranged in a crystal structure. There, printing inks are described which have a multiplicity of particles in a printing medium 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 used. This crystal structure ensures that light of a specific wavelength 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 of a structural color, since a geometric arrangement of the colloidal particles is responsible for the expression of the color. It is known to use such structural colors for the manufacture of objects whose color impression is easily changeable to a human observer.

The WO2012 / 130370 A1 describes an optically variable security element for securing valuables with an optically variable ink layer. It is envisaged there that the optically variable ink layer contains a plurality of microcapsules, each having a capsule shell, a carrier liquid enclosed in the capsule shell and at least one optically variable and magnetically alignable pigment which is substantially freely rotatable in the microcapsule and by an outer Magnetic field is reversible aligned and which is multi-layered with at least one magnetic layer and at least one non-magnetic layer (eg, silica or graphene layers as a carbon coating, as oxidation protection) is formed.

The WO2010 / 142391 A1 describes a security element with an external magnetic field changeable optical appearance. According to the invention, the security element has a large number of microcapsules which contain a suspension of a carrier liquid and magnetic nanoparticles which reversibly form a photonic crystal in the microcapsules in an external magnetic field of a magnet.

The US 2012/104102 A1 describes a document which comprises: a support defining at least two sections connected at at least one fold line, a structure movably connected to the support, in particular at the fold line, extending at least partially between the two sections, when the document is folded, the structure comprising: a fibrous layer, a substructure comprising a translucent region, a watermark or pseudo-watermarks supported by the fibrous layer and at least partially overlying the transmissive region of the substructure, wherein the watermark or pseudo-watermark is adapted to be observable by means of light transmitted through the structure, in the translucent region of the substructure, and only from the side of the structure disposed on the side of the fiber layer.

From the DE 10 2009 023 982 A1 For example, there is known a security element having a visual impact variable by an external magnetic field that includes a plurality of core-shell particles. There, it is contemplated that the core of the core-shell particles contains a magnetic fluid and a non-magnetic phase visually distinguishable from the magnetic fluid, which is movably disposed within the magnetic fluid.

From the DE 10 2009 024 447 A1 a security element is known with an external magnetic field changeable optical appearance, wherein it is provided that the security element comprises a plurality of microcapsules containing a suspension of a carrier liquid and magnetic nanoparticles which reversibly in an external magnetic field in the microcapsules a photonic To form crystal.

• die zumindest eine Hohlkammer mit einem Füllmaterial mit einem Sicherheitsmerkmal gefüllt ist,
• die zumindest eine Hohlkammer auf beiden Seiten des Substrats jeweils mit einer zumindest teilweisen lichtdurchlässigen Abdeckfolie abgedeckt ist, und dass
• die zumindest eine Hohlkammer eine durch die Substratdicke am Rand der Hohlkammer definierte Hohlkammertiefe aufweist, die zwischen 0,5 µm und 140 µm liegt.

The DE 10 2011 108 477 A1 describes a security element for securing valuables with a substrate having a window containing at least one through the substrate continuous hollow chamber. There it is provided that

• the at least one hollow chamber is filled with a filling material having a security feature,
• the at least one hollow chamber is covered in each case with an at least partially transparent cover film on both sides of the substrate, and in that
• the at least one hollow chamber has a hollow chamber depth defined by the substrate thickness at the edge of the hollow chamber, which lies between 0.5 μm and 140 μm.

It is a general endeavor to develop security documents in such a way that they contain security elements and features which are harder to imitate and / or manipulate for counterfeiters.

The invention is therefore the technical object of the invention to provide a novel security element and a method with which the security element is verifiable in a simple manner.

Basic idea of the invention

The invention is based on the idea to provide a security feature and a security element comprising at least three separate components, of which either two are arranged spatially separated on a substrate layer and the at least third component arranged on a further substrate layer connected to the one substrate layer or, alternatively, the at least three components are arranged on three different substrate layers, which are interconnected. On the one substrate layer, a security structure with a structure color is formed, which is designed so that it shows an altered reflection and / or transmittance for light depending on an electric or magnetic field in the region of this security structure and causes a different color impression. The second and at least third components are each an excitation structure, which is designed such that it generates an electric and / or magnetic field. In the case of a surface overlay of the security structure and one or more of the excitation structures, a color impression of the security structure is thus changed in comparison with a state in which the security structure is not superposed with any of the excitation structures.

Thus, a novel security element is created, which can be checked for its presence and its integrity by means of a novel verification procedure.

definition

The planar overlaying of two structures which are arranged on one substrate layer or on two different substrate layers means the parallel alignment of the respective substrate layer sections or entire substrate layers on which the two structures are arranged. In parallel, the substrate layer sections or substrate layers are oriented such that a projection of the one structure parallel to the surface normal of the substrate layer section on which this structure is formed is projected onto the other substrate layer section or the other substrate layer. If the surface of the projected structure overlaps with the other structure formed on the substrate layer portion or other substrate to which the projection is made, there is a surface overlay. If the projection of one structure completely covers the other structure, one speaks of one complete overlay. If the two substrate layer sections are curved, they are considered to be parallel if their curvatures have the same center of curvature.

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.

Entities having at least one security feature are referred to as security elements. Thus, any physically trained object that includes at least one security feature is a security element.

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.

Value documents are security documents to which a value is assigned, e.g. Banknotes, postage stamps etc.

Pigments which show emission of light as a result of excitation, for example exposure to UV light, are referred to as luminescent pigments. The emission caused by the excitation is referred to as luminescence, the excitation as luminescence excitation. 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 environmental conditions and / or excitation are referred to as body colors.

Printing preparations or printing inks or inks, the 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 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.

A color of light is determined by a wavelength of light. Such a color is also called spectral color since, when a radiation comprising light of a continuous wavelength spectrum is split into wavelength-selective components, this component in each case produces a color impression characteristic of the selected wavelength.

As white light is here considered an electromagnetic broadband radiation with a continuous wavelength spectrum.

From the prior art, in particular the EP 2 463 111 A2 are known pressure preparations, which are structural colors. There are described printing preparations 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 formed so that the printing preparation comprises microcapsules enclosing a substrate or medium in which in turn a plurality of colloidal particles are arranged which have an electrical or magnetic property and in an electric or magnetic field relative to each other to a crystal or to arrange a 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), polyvinyl chloride (PVC), polyethylene terephthalate (PET), etc. In other embodiments, uncharged particles may be coated with a charged material. For example, particles may be coated with metal inorganic oxides such as silicon oxide SiO _x , titanium oxide TiO _x , etc. However, 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.

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. Upon application of a voltage to electrodes of an article to form a field in the article, this field is not considered intrinsic.

If the orientation of the colloidal particles is brought about only by the electric field, the space is considered to be field-free if there is no electric field even if, for example, a magnetic field is applied to influence a viscosity of a magnetorheological fluid in the space ,

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.

A field strength which causes a structure excitation is denoted by M _SA . An adjusted parenthetical expression (λ = λ ₁ ) expresses that the structure excitation in the structure color causes an influence of light with the wavelength λ ₁ . For example M _SA (λ = λ ₁ ) expresses that the structure excitation causes the structure color to influence light in the wavelength λ ₁ .

As individualizing information is meant information that is individual to a document or object and, when associated with, for example, stored in the object, makes that object distinguishable from other similar objects. If the content of the individualizing information contains information about a person to whom the object or a document is assigned, this individualizing information is referred to as personalizing information. A serial number is for example an individualizing information for a document. A name, date of birth, or other biometric information, such as a facial image or fingerprints, are examples of personal information.

Preferred embodiments

According to the invention defined in claim 1 overlay security element is created.

Furthermore, according to the invention a method as defined in claim 9 for verifying an overlay feature of an overlay security element is provided.

The invention provides an easy-to-verify security element and feature as well as such a verification method which enable a very good security of a security document against unauthorized production. A verification is easily possible without external aids and shows a clear, easy-to-perceive and difficult-to-imitate effect. As a result, a very high security for a security document is produced, which has this overlay security element.

The structure color is formed so that the effect occurring in the superimposed state is reversible when the non-superposed state is brought about. Furthermore, the effect is repeatable. The excitation structure in a preferred embodiment comprises magnetic materials. These are preferably designed so that they permanently generate a magnetic field. Thus, in establishing the superimposed state, the magnetic field generated by the magnetic materials of the excitation structure interacts with the magnetic property colloidal particles in the microcapsules of the structural color and results in the formation of the crystal lattice-like structure of the colloidal particles. This in turn causes the change in the optical properties of the crystal structure and thus the color impression, which shows the crystal structure in the interaction with light.

The excitation structure is laterally structured in a preferred embodiment. This means that, for example, an arrangement of the magnetic materials on the substrate layer alphanumeric characters, pictograms or the like can be formed. The magnetic materials may be contained in the form of magnetic particles in an ink or printing preparation and thus printed in a structured manner in a simple manner. Alignment of the magnetic particles may be accomplished by forming a magnetic field during printing of the magnetic ink or subsequent to establishing the excitation structure via exposure to a very strong external magnetic field. As a result, the magnetic particles can optionally be re-magnetized in order to achieve a parallel magnetization direction, so that a particularly strong magnetic field for the Structural stimulation of the security structure is provided. The structuring of the excitation structure makes it possible to store information that can be detected and evaluated during verification.

In one embodiment, it is provided that the structure color of the security structure is formed flat homogeneous. Regardless of the precise lateral alignment of the security structure and the excitation structure in the superimposed state, in such an embodiment the information stored via the lateral structuring of the excitation structure can be easily recognized during verification, since a color change of the structure color does not occur in a planar manner, but only local Color changes occur which are correlated with the lateral structure of the excitation structure.

A further development of the verification method thus provides that an information represented by the differences is derived and compared with an expected information and the overlay feature is only verified as genuine if a derived information corresponds to the expected information. It is essential here that the magnetic materials, ie the magnetic particles, can be applied to the one substrate layer or the further substrate layer such that the lateral structure deviates from an optically perceptible, preferably color-coded, graphically detectable structure or appearance. This can be achieved in that, for example, the excitation structure formed by the magnetic particles is overprinted by a graphic, for example, colorful and multi-colored structure. It is likewise possible to produce a printed image with metameric colors, which are colors which, although they produce the same color impression, differ in at least one physical property, here for example a magnetic property. One set of printing inks does not include magnetic particles, the other set of printing inks. The color that can be displayed with the two sets is identical. So it is possible to create a full color colorful graphic image and still form in this image any laterally structured magnetic structure. The information stored by the magnetic materials in the excitation structure is thus not discernible by an optical observation of the excitation structure and only shows itself on verification by the color change caused in the superposition state of the structure color of the security structure.

In another embodiment of the invention may alternatively or additionally be provided that a lateral position of the security structure relative to the excitation structure is changed in the superimposed state and another overlay image is detected and deviations between the overlay map and the other overlay map are determined and the overlay feature only as is verified if the deviations found correspond to expected deviations. This means that, for example, a written over the magnetic materials in the excitation structure lettering in an overlay by the security structure just emerge this lettering about color changes in the security structure. Now, if a lateral displacement, i. parallel to the substrate layer sections, made in which the security structure and the excitation structure are formed, so the recognizable by the color change lettering moves in the security structure and can thus be used to verify the overlay feature.

In an alternative embodiment, the security structure may be structured or structured in a specific area. If the structuring of the security structure coincides with a structuring of the excitation structure, then the information stored in the excitation structure can be completely detected only in the case of an optimal lateral alignment in the superimposed state.

Such an overlay feature is particularly suitable for an application in a booklet, for example a passbook.

In one embodiment, it is therefore provided that the at least one substrate layer is a booklet or is part of a booklet and the further substrate layer is another booklet or part of another booklet and a booklet and the other booklet are joined together in a booklet. As a booklet, an article is considered in which substrate layers on one side and along the side are non-detachably connected to each other.

Preferably, the security structure and the excitation structure are each formed at the same side position of their corresponding booklet page. A flat Overlaying then takes place in the closed state of the booklet. Assigning the individual surfaces of the booklet page consecutively, as is customary in books, a number, in such a way that one front and one back of a physical book page is assigned a different numbers, so a two-dimensional superimposition then takes place when a front side of the booklet side on which the security structure is formed, ie, the side which is associated with the smaller number, is opened and the excitation structure is arranged on a booklet page, the larger numbers assigned to the front and the back of the corresponding book page are. If, however, the excitation structure is arranged on a book page with a lower assigned number, then a surface overlay occurs when the rear side of the book page is opened, on which the safety structure is formed.

A booklet page can consist of a homogeneous substrate layer, for example based on pulp. Alternatively, however, a booklet side may also be a plastic film or a lamination body composed of a plurality of substrate layers, for example, thermoplastic substrate layers. A security structure can be formed on one of these substrate layers, preferably on a substrate layer, which forms an inner material layer in the lamination body. It is understood that such a lamination body forming a booklet page, as well as "simple" booklet page may include a variety of other different security features.

In order to enable the safety structure to be viewed from both the front side and the back side of the lamination body or the substrate layer, it is preferably transparent to visible light at least in the section in which the safety structure is formed.

Also conceivable are embodiments in which one of the pages has a projection over the remaining pages and either the security structure or an excitation structure in the region of the supernatant is formed. Preferably, the booklet side with the supernatant on a folded edge on which the supernatant can be folded, so that in the closed state of the booklet, the supernatant does not protrude beyond the remaining booklet pages. For verification, the supernatant can then be folded over any page of the booklet to a planar overlay with an excitation structure or security structure on any other side. For example, all pages of a passport book can be checked for authenticity and integrity.

If, for example, an excitation structure is realized in the supernatant, which is laterally structured on the individual passbook pages, a respective index number is printed as a security structure with a structure color, a color change of the numbers can be verified during verification and thus checked, if all pages of the booklet are present or individual pages have been removed and / or replaced. In this case, embodiments may provide that the individual index digits are printed on the individual passbook pages in such a way that, in the non-superimposed state, the digit produced by the structure color of the security structure is not graphically recognizable. This can be achieved by printing the surrounding sections, not printed by the digits of a print area for the security structure, with a body color which has an identical color impression to the structure color in the unexcited state.

Analogously, embodiments are possible in which excitation structures are applied to the individual pages and on the overhang a flat safety structure in the form of a structural color is formed.

In one embodiment it is provided that the material of the one substrate layer and, if other substrate layers are joined to the one substrate layer for forming the one book page, also the material of these other substrate layers are transparent to light in the visible wavelength range, so that the security structure formed by the structure color is optically detectable by both opposing surfaces of a booklet page.

In particular, in one embodiment in which the substrate layer or the substrate layer section in which the security structure is formed is transparent to visible light, an additional substrate layer can be provided in addition to an excitation structure on a further substrate layer, as a booklet or as part of an additional A booklet side is connected to the substrate layer and the further substrate layer to the booklet, wherein the one substrate layer in the booklet between the additional substrate layer and the further substrate layer is arranged. If the front side of the one substrate layer with the security structure is struck, superposition with the excitation structure of the further substrate layer preferably occurs. However, if one looks at the booklet so that one looks at the back of a substrate layer, the security structure superimposed on the additional excitation structure, which is preferably different from the excitation structure on the other substrate layer structured so that different information emerge in color in the security structure, depending after considering in the otherwise transparent section the front or the back of the one book page in the opened booklet. At the same location, therefore, different color changes are caused depending on the superimposed excitation structure.

If the booklet is opened in such a way that the one substrate layer on which the security structure is formed is oriented essentially perpendicular to the further substrate layer and the additional substrate layer, information can not be detected either on the front or on the back side. This behavior can also be used for verification.

In one embodiment, the overlay feature on a booklet page is verified by flipping the booklet side formed of the substrate layer onto which the security structure is applied so that the booklet overlays the further booklet face comprising the further substrate layer on which the excitation structure is trained.

In another embodiment, information represented by the differences is derived and compared to expected information, and the overlay feature is verified as genuine only when the derived information corresponds to the expected information.

In yet another embodiment, it is envisioned that an alternative overlay condition be established by overlaying the security structure of another excitation structure and detecting another overlay map and comparing the other overlay map with the overlay map and verifying the overlay feature as genuine only when a difference between the other overlay map of an overlay map corresponds to an expected difference.

In yet another embodiment, it is provided that the other overlapping state is produced, in which, starting from the overlapping state, the booklet page comprising the substrate layer on which the security structure is formed and whose surface is detected when detecting the overlay image is turned over and Detecting the other overlay image, the opposite surface of the booklet side is detected.

In one embodiment, it is provided that the perceptible change in the color impression between the non-superposed state of the security structure and an excitation structure or multiple excitation structures and the superimposed state comprise individualizing information and / or personalizing information. This can be brought about by lateral structuring of the security structure and / or the excitation structure and / or excitation structures. In addition, the individualizing information and / or the personalizing information may additionally be stored openly perceptible or hidden in the security document or the overlay security feature in order to facilitate a verification via a comparison of this stored information with the information determined on the basis of the change in the color impression.

Fig. 1a - 1c

schematische Darstellungen einer Mikrokapsel einer Strukturfarbe zum Erläutern eines Strukturfarbeffekts, abhängig von einer Strukturanregung;

Fig. 2a - 2c

eine schematische Darstellung von Mikrokapseln zur Erläuterung eines Strukturfarbeffekts bei einer zweiten Ausführungsform;

Fig. 3a

eine schematische Ansicht eines mittels einer Substratschicht ausgebildeten Sicherheitsdokuments, welches ein Überlappungssicherheitsmerkmal aufweist, wobei Figur 3a eine Vorderseite des Sicherheitsdokuments zeigt;

Fig. 3b

eine schematische Ansicht der Rückseite des Sicherheitsdokuments nach Fig. 3a;

Fig. 3c

eine schematische Ansicht des Sicherheitsdokuments nach Fig. 3a und 3b, wobei ein Rückseitenabschnitt über einen Vorderseitenabschnitt geklappt ist, um einen Überlagerungszustand zwischen einer Sicherheitsstruktur und einer Anregungsstruktur herbeizuführen;

Fig. 3d

schematische Ansicht ähnlich zu der nach Fig. 3c, wobei die Sicherheitsstruktur und die Anregungsstruktur im überlagerten Zustand lateral abweichend positioniert sind;

Fig. 3e

einen anderen Überlagerungszustand des Sicherheitsdokuments nach Fig. 3a und 3b;

Fig. 4a

eine Explosionsdarstellung von mehreren Büchleinseiten;

Fig. 4b

ein aus dem in Fig. 4a dargestellten Büchleinseiten gefertigtes Büchlein in einer aufgeschlagenen Stellung, in der eine Vorderseite der Büchleinseite, in der die Sicherheitsstruktur ausgebildet ist, aufgeschlagen ist;

Fig. 4c

das Büchlein nach Fig. 4b, wobei die aufgeschlagene Büchleinseite mit der Sicherheitsstruktur lateral gegenüber übrigen Büchleinseiten verschoben ist;

Fig. 5a

eine schematische Explosionsdarstellung eines weiteren Büchleins;

Fig. 5b

eine schematische Darstellung, des Büchleins nach Fig. 5a, bei dem eine Vorderseite der Büchleinseite aufgeschlagen ist, in der die Sicherheitsstruktur ausgebildet ist, wobei die Sicherheitsstruktur lateral strukturiert ist;

Fig. 5c

eine weitere schematische Ansicht des Büchleins nach Fig. 5b, wobei die eine Buchseite mit der Sicherheitsstruktur lateral relativ zu den übrigen Büchleinseiten verschoben ist;

Fig. 6a

eine Explosionszeichnung noch eines weiteren Büchleins;

Fig. 6b

eine schematische Ansicht des Büchleins nach Fig. 6a, bei dem eine Vorderseite einer Büchleinseite mit der Sicherheitsstruktur aufgeschlagen ist;

Fig. 6c

eine schematische Ansicht des Büchleins nach Fig. 6a und 6b, in der die Büchleinseite mit der Sicherheitsstruktur senkrecht zu den übrigen Seiten des Büchleins orientiert ist;

Fig. 6d

eine schematische Ansicht des Büchleins nach Fig. 6a bis 6c in einer Situation, in der die Rückseite der Büchleinseite mit der Sicherheitsstruktur aufgeschlagen ist;

Fig. 7a

eine Explosionszeichnung eines weiteren Büchleins, wobei eine Büchleinseite einen Überstand aufweist;

Fig. 7b

eine schematische Ansicht des Büchleins nach Fig. 7a, bei dem eine der Seiten aufgeschlagen ist und der Überstand über ein Ende der aufgeschlagenen Seite umgeklappt ist;

Fig. 8a

schematische Explosionszeichnung eines Büchleins, bei dem eine Büchleinseite eine Sicherheitsstruktur und die übrigen Büchleinseiten jeweils eine Anregungsstruktur aufweisen, die gemeinsam eine Information kodieren;

Fig. 8b

eine schematische Ansicht des aufgeschlagenen Büchleins nach Fig. 8a, wobei die Büchleinseite mit der Sicherheitsstruktur alle übrigen Büchleinseiten überlagert;

Fig. 8c

eine Schematische Ansicht ähnlich zu der nach Fig. 8b, wobei aus dem Büchlein jedoch eine der übrigen Büchleinseiten entfernt ist.

Fig. 9

ein schematisches Ablaufdiagramm eines Verifikationsverfahrens.

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

Fig. 1a - 1c

schematic representations of a microcapsule of a structure color for explaining a structural color effect, depending on a structure excitation;

Fig. 2a - 2c

a schematic representation of microcapsules for explaining a structural color effect in a second embodiment;

Fig. 3a

a schematic view of a formed by a substrate layer security document, which a Overlap security feature, wherein FIG. 3a shows a front side of the security document;

Fig. 3b

a schematic view of the back of the security document after Fig. 3a ;

Fig. 3c

a schematic view of the security document after Fig. 3a and 3b wherein a rear side portion is folded over a front side portion to cause a superposition state between a security structure and an excitation structure;

Fig. 3d

schematic view similar to the Fig. 3c wherein the safety structure and the excitation structure are positioned laterally deviating in the superimposed state;

Fig. 3e

another overlay state of the security document Fig. 3a and 3b ;

Fig. 4a

an exploded view of several book pages;

Fig. 4b

one from the in Fig. 4a booklet pages produced booklet in an open position in which a front of the booklet page, in which the security structure is formed, is open;

Fig. 4c

the booklet after Fig. 4b , wherein the opened book page with the security structure is laterally displaced from the remaining book pages;

Fig. 5a

a schematic exploded view of another booklet;

Fig. 5b

a schematic representation, the booklet after Fig. 5a in which a front side of the book page is opened, in which the safety structure is formed, wherein the safety structure is laterally structured;

Fig. 5c

another schematic view of the book after Fig. 5b wherein the one book page with the security structure is laterally displaced relative to the remaining booklet pages;

Fig. 6a

an exploded view of yet another booklet;

Fig. 6b

a schematic view of the booklet after Fig. 6a in which a front side of a book page with the security structure is opened;

Fig. 6c

a schematic view of the booklet after Fig. 6a and 6b in which the booklet page with the security structure is oriented perpendicular to the remaining pages of the booklet;

Fig. 6d

a schematic view of the booklet after Fig. 6a to 6c in a situation where the back of the booklet side with the security structure is opened;

Fig. 7a

an exploded view of another booklet, wherein a booklet has a supernatant;

Fig. 7b

a schematic view of the booklet after Fig. 7a in which one of the sides is opened and the supernatant is folded over one end of the open side;

Fig. 8a

schematic exploded view of a booklet, in which a book page have a security structure and the remaining pages each have an excitation structure, which together encode information;

Fig. 8b

a schematic view of the open booklet after Fig. 8a , wherein the book page with the security structure superimposed on all other book pages;

Fig. 8c

a schematic view similar to the Fig. 8b , but from the booklet one of the remaining book pages is removed.

Fig. 9

a schematic flow diagram of a verification process.

Based on Fig. 1a to 1c and 2a to 2c is to be explained schematically by way of example the mode of action of different structural colors, which each contain microcapsules 10. The same technical features are provided in the figures with the same reference numerals. A structural ink contains a plurality of such microcapsules 10, which are responsible for the color impression or the color of the structure color. The microcapsules 10 each have a shell 11 which encloses a transparent substance 12 with colloidal particles, eg nanoparticles 13, contained therein. The sheath 11 is formed of a transparent material. The substance 12 is also transparent and constitutes a fluid in which the nanoparticles 13 according to the embodiments Fig. 1a to 1c, 2a to 2c can also move in the printed state. The nanoparticles are, for example, paramagnetic or superparamagnetic 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 inks containing such microcapsules and resulting in visible wavelength range dyeing are also available from Nanobrick, Gyeonggi-do, Korea.

One embodiment is in Fig. 1a to 1c shown. In Fig. 1a a microcapsule 10 is shown in the field-free space. The colloidal nanoparticles are arranged irregularly. The microcapsules 10 of the colloidal nanoparticles 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 a magnetic field with a field strength M1 is applied, the paramagnetic or superparamagnetic nanoparticles align themselves to form a lattice-like crystal structure 15. This is in Fig. 1b and 1c shown. A ratio of the magnetic field strength M1 or M2 to the susceptibility determines a lattice spacing of the nanoparticles. Another influencing factor is the particle size.

The crystal structure thus formed has characteristics of a photonic crystal. In this, propagation is only possible along certain spatial directions for some wavelengths. 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 Fig. 1b In the case of the field strength M1, an orange wavelength component is reflected, for example, in the case of illumination with "white" light of a black body radiator. If the magnetic field strength is increased to a value M2> M1, a distance between the nanoparticles is reduced. This changes the crystal structure so that, for example, a blue component is now reflected from the "white" light of a black body radiator so that the microcapsule shows a blue color. This is in Fig. 1c shown.

In the Fig. 2a to 2c another embodiment of microcapsules 10 is shown schematically. These differ in that the colloidal particles already in the field-free space in the microcapsule 10 have a crystal structure 15, so that, for example, an orange color component of the light 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 of the light is reflected. If the field strength continues to increase ( Fig. 2c ), the grid spacing becomes even smaller, so that again a blue color component of the light is reflected again.

In Fig. 3a schematically a security document 30, which comprises a substrate layer 31, shown. In Fig. 3a a view is shown on a front side 41, which is indicated by the letter "V". In a section 51 of the front side 41 of the substrate layer 31, an excitation structure 61 is formed, which is laterally structured such that it represents the shape of the letter "F". The excitation structure 61 is formed by means of magnetic particles, which are for example printed with an ink. These are added in one or more different inks with which section 51 is printed. Overall, the portion 51 is preferably printed so that its overall appearance shows a different optical information than that given by the lateral structuring of the excitation structure 61. This is indicated here by way of example by hatching 62.

Upon detection of an optical image 201 of the section 51 on the front side of the substrate layer 31 or of the security document 30, a uniformly colored homogeneous surface is therefore perceived in the illustrated embodiment. In other embodiments, an image, lettering, or the like, which is different from the lateral structure formed by magnetic materials, may be noticeable here. As a result, the structure formed by the magnetic particles remains hidden to a viewer.

In Fig. 3b is a rear side 42 of the security document 30 after Fig. 3a shown. Here, the security document 30 is after a lower edge 39 of the security document after Fig. 3a folded down, as indicated by a case 101. In Fig. 3b a section 71 can be seen, in which a homogeneous flat safety structure 81 is formed by means of a structure color which changes its color impression depending on a magnetic field strength in the region of the safety structure. A letter "R" indicates that in Fig. 3b a plan view of the back of the security document 30 is shown. The elements which are located on the viewed side of the security document are each shown by solid lines, while elements located on the opposite hidden side are shown in dashed lines.

The security structure 81 can convey a homogeneous color impression or it can also be transparent so that the substrate layer 31 is visible through the security structure, or if it is transparent, it can be seen through the substrate layer 31.

In Fig. 3c For example, the security structure 81 of the excitation structure 61 is superimposed on a surface by the security document 30, as indicated by arrow 102 in FIG Fig. 3a indicated, with a left half 43 folded over a right half 44. Due to the magnetic field, which is caused by the excitation structure in the form of the capital letter "F", color changes are caused locally in the structure color of the security structure 81, which together also form the shape of the capital letter "F" of the excitation structure. A captured image 203 of the portion 71 in which the security structure 81 is formed thus shows as differences 92 to a figure 202 of FIG Fig. 3b , which is detected by the security structure in the non-superimposed state, as differences 92 those areas that have color changes 91 and together form the shape of the capital letter "F".

In order to enable verification of the information presented by the differences 92, the information stored in the excitation structure 61, here the capital letter "F", may additionally be stored in the security document 30. The storage may be encoded or non-encoded electronically in a microchip (not shown) or otherwise as an imprint, in a hologram, or the like.

In Fig. 3d the security document 30 is in an overlay state similar to that of Fig. 3c however, the safety structure is arranged laterally, ie parallel to the plane in which the safety structure 81 and the excitation structure 61 are oriented in the superposed state, displaced from the superposition state 3c. It can be seen that due to the other lateral arrangement, the color change 91 occurs within the security structure 81 at another position. If one compares the for the superposition state of the Fig. 3d captured Figure 204 with the figure 203, which in the superposition state of Fig. 3c is detected, it can be seen that a shift d1 of the letter "F" formed by the color differences 92 corresponds to a displacement d2 of the excitation structure 61 relative to the security structure 81. This behavior can also be used to verify the security document 30. Only when such an expected shift occurs is the security document genuine.

In Fig. 3e another superposition state of the security structure 81 is shown via the excitation structure 61. For this purpose, the security document 30, as in Fig. 3a indicated by arrows 103 and 104, so to speak coiled, so that the security structure 81 located on the back 42 is not directly superimposed on the applied excitation structure but the back 42 in that area in which the portion 51 is formed with the excitation structure 61 on the front side 41. Since the magnetic field lines extend through the substrate layer 31, they also cause local color changes 91 in this superimposed state in the area of the security structure 81, which together form the shape of a capital letter "F", now mirrored in the consideration. This can be clearly seen in Figure 205 of the security structure 81.

In the in the Fig. 3a to 3e illustrated embodiments of a security document 30, the overlay feature can thus be verified in two different overlay positions, which show similar, but slightly different images 203, 204, 205.

In Fig. 4a schematically an exploded view of a booklet 130, for example, a Passbook, shown, which is formed from substrate layers 31 to 34 and a cover 120. On the substrate layer 31, a safety structure 81 of homogeneous surface is printed again. The substrate layer 31 later forms the booklet side 131. On a further substrate layer 32 is at the same page position with respect to the subsequent booklet side 132 an excitation structure 61, applied in this case in the form of a capital letter "A", which again by surrounding imprinted image components in front of a direct optical Contemplation is hidden. This is indicated again by a hatching 62.

In Fig. 4b the booklet 130 is shown in an open position, in which a front side 41 of a booklet page 131 is opened, which is formed from the substrate layer 31, on which the security structure 81 is applied. In this position, the security structure 81 overlaps the excitation structure, which is arranged on the following booklet side 132 below the booklet side 131. Therefore, in an image 206 of the security structure 81, the capital letter "A" can be recognized in the form of color changes 91.

In Fig. 4c the booklet page 131 is laterally laterally displaced with respect to the booklet page 132 with the excitation structure, so that the color differences 91, which form the shape of the capital letter "A", can be seen elsewhere in the security structure 81 and the image 207 taken therefrom. A shift of the capital letters "A" formed by the differences corresponds again to a relative displacement of the two side edges 141, 142 of the book pages 131 and 132 against each other.

In Fig. 5a to 5c are an exploded view and a suitably opened booklet 130, as in the Fig. 4a to 4c shown, wherein this embodiment differs in that the security structure 81 is not formed flat homogeneous, but also has a structure in the form of a slightly wider executed capital letter "A". In the opened state, in which edges 141, 142 of the booklet pages 131, 132 overlap one another, in the captured image 208 the capital letter "A" in the security structure can be recognized again as color change 91. If, however, the booklet page 131 is displaced relative to the booklet page 132, only part 93 of the capital letter "A" of the excitation structure 61 can be recognized in the safety structure 81, since only that part 93 of the letter "A" of the excitation structure 61 in the illustration 209 is visible, which is superimposed in the overlay state by a part of the security structure in the form of the widened capital letter "A". It thus shows a significantly different effect from that of the embodiment Fig. 4c ,

In Fig. 6a to 6d another embodiment of passport 130 is shown. In Fig. 6a a corresponding exploded view is shown, in which the individual substrate layers 31 to 37 and later book pages 131 to 137 can be seen. In addition to the one booklet page 131 with the security structure 81 and another booklet page 133 on which the excitation structure 61 is again formed in the form of a capital letter "A", in at least one additional substrate layer 35 or booklet page 135 is an additional excitation structure 63, which Form a capital letter "B" has introduced. The additional substrate layer 35 or booklet side 135 is arranged such that the one substrate layer 31 or booklet side 131 with the safety structure 81 is arranged between the further booklet side 133 and the additional booklet side 135. If you look at the booklet 130 in such a way that one looks at a front side 41 of the booklet page 131 with the security structure 81, so this superimposed not on the immediately following booklet page 132 but next book page 133 arranged excitation structure 61. Nevertheless, a color change 91 in the shape of a capital letter "A" in the security structure 81, as shown in Figure 210.

If the booklet page 131 is turned over and viewed while it is oriented perpendicular to the remaining booklet pages 132 to 137, no information in the form of color changes 91 can be recognized in the security structure. This is in Fig. 6c schematically by means of the recorded image 211 of the front side 41 and the recorded image 212 of the back 42 of the booklet page 131 with the Security structure 81 to recognize. It should be noted here that the booklet side 131 is transparent at least in a section 71 except for the safety structure 81, which optionally has a homogeneous color.

If passbook page 131 is completely scrolled back, as shown in Fig. 6d is shown, the security structure 81 of the booklet side 131 superimposed on the additional excitation structure 63 on the booklet page 135, so that now the capital letter "B" in the security structure 81 and the image 213 can be seen in the form of a color change 91. Depending on which side of the security structure 81 is considered and which excitation structure 61, 63 is concretely superimposed, a different information about the color change 91, which is caused by the magnetically formed excitation structures, is thus observable. If no excitation structure is superimposed, no color change occurs. The security structure 81 is then either completely transparent or homogeneous monochrome.

In Fig. 7a an exploded view of another booklet 130 is shown schematically. In this embodiment, a last booklet page 131 is larger than the remaining booklet pages 132 to 138 formed. In a supernatant 160 of the booklet page 131 is applied as a security structure over the entire surface of a structure color to the otherwise preferably transparent material of the supernatant 160. The individual book pages 131 to 138 comprise in edge strips 151 to 158 in each case an identifier 161 to 168, for example in the form of a number associated with the respective book page. These are arranged parallel to the respective booklet side edge 142 to 148 laterally offset from one another.

In Fig. 7b the booklet is shown in an open position, wherein the supernatant 160 is folded over the edge stiffeners 151 to 154 of a portion of the open book pages. The identifiers 161 to 164 of the peripheral stiffeners 151 to 154 of the book pages 131 to 134 overlaid by the overhang 160 can then be recognized as color changes 91 in the security structure 81. Here are examples of the numbers "1", "2", "3", "4". These are the book pages 131, 132, 133, 134 assigned accordingly, as in Fig. 7a is indicated.

The individual identifiers 161 to 168, here the numbers "1" to "8", are applied via magnetic particles. These particles are contained, for example, in inks. Thus, you can the identifiers 161 to 168 are printed or be. In order to hide the identifiers, the edge strips 151 to 158 are additionally printed with normal body colors so that the identifiers 161 to 168 can not be recognized. This is again schematically indicated by a hatching 62. In this embodiment, all the book pages 131 to 138 can be checked individually and individually for the existing identifier 161 to 168. If the identifiers 161 to 168 are assigned consecutively, for example, from the last page 131 to the first page 138 for the individual book pages 131 to 138, the booklet 130 can simply be checked for completeness of the book pages 131 to 138.

Such an examination is also possible with an embodiment in which the security structure is formed over the entire marginal strip of a top passport page and identifiers are arranged in the corresponding edge strips of the passbook pages arranged underneath, the laterally offset relative to the identifiers of the other passport pages in the edge strips are arranged.

In the described embodiments, it was assumed in each case that the security structure and the excitation structures are respectively applied to individual substrate layers, preferably printed. However, it is also possible that such a substrate layer, to which the security structure in the form of a structural color or the excitation structure is applied by means of magnetic materials, is joined together with further substrate layers to form a composite body and the composite body is used as security document or booklet page of a booklet. For example, it may be provided in one embodiment that the excitation structure is arranged in the interior of an individualization card manufactured from thermoplastic materials. The remaining booklet pages of a passbook can then each have a security structure in the form of a textured color imprint. For example, this imprint is printed in each case on the backs of the individual booklet pages at that position corresponding to a position of an excitation structure arranged on the side of the passbook formed as a lamination body. If one leafs through such a booklet from behind, then the information stored in the excitation structure is to be seen on the rear sides, provided that the security document body with the excitation structure is inserted as the first book page in the booklet. When turning over (quasi backward) in the booklet then disappears the perceptible information as soon as the back the remaining pages are no longer overlaid. As a result, all pages can be checked at least for the presence of a security structure in the form of a structure color.

Analogously, embodiments are conceivable in which the security structure is arranged in the lamination body, preferably in a transparent window area. The individual remaining pages of the booklet can each comprise an excitation structure, which are matched to one another such that, when all the book pages are superimposed, information is coded together. For example, the individual booklet pages may each have a circle segment section 171 to 174 of a circle 175, wherein each book page 132 to 135 has a different sector section of the circle. This is exemplary in the Fig. 8a and 8b shown. Fig. 8a shows an exploded view of the booklet 130. Fig. 8b shows the open booklet 130 in that situation in which the booklet page 131, which is formed as lamination body with the security structure 81, all other book pages superimposed with their excitation structures 63 to 66 and thus in the security structure 81 a figure 170 in the form of a full circle 175th can be seen. This is in Figure 214 of the Fig. 8b to recognize. If a booklet page 135 is removed from the booklet 130, this can be recognized immediately, since in the figure 170 protruding through the color change 91 a circular section 174 is missing. A captured image 214 of a security structure of such a damaged booklet is shown in FIG Fig. 8c exemplified.

Based on Fig. 9 Let us briefly explain an exemplary embodiment of a verification method 500. First, a security document is provided 510 to be verified as to whether a correct overlay security element exists. In addition, a non-superimposed state is established 520 in which the security structure is superimposed on an excitation structure areally. In this non-superimposed state, an image of the security structure or of that section is detected 530 in which the security structure is formed. Subsequently, an overlay state is produced 540, in which the security structure superimposed on an excitation structure or a portion in which the security structure is to be formed, is superimposed flat over a section in which an excitation structure should be present. Subsequently, another illustration of the security structure or the section in which the security structure is formed 550. Subsequently, the two acquired images are compared and differences in the form of color changes are determined 560. On the basis of the differences in the color perception of the images, a verification decision is made as to whether the security feature is present and possibly additional additional specifications 570. It can be examined whether the color changes encoded a certain information. Additional steps may also be performed, such as changing the overlay state, and capturing further mappings that are also examined for differences in the detected color changes, as discussed in more detail above in connection with the individual embodiments.

It is understood that only exemplary embodiments are described here. The features described in the different embodiments can be combined in any combination for the realization of the invention, insofar as this is covered by the scope of the claims. The alphanumeric characters used in the embodiments such as "A", "B", etc., or symbols such as the circle segments in FIG Fig. 8a to 8c , can be individualizing and / or personalizing information.

LIST OF REFERENCE NUMBERS

10

microcapsule

11

shell

12

substance

13

colloidal particles

15

lattice structure

30

The security document

31 to 38

substrate layers

39

lower edge

41

front

42

back

43

left half

44

right half

51

section

61

excitation structure

62

hatching

63

additional excitation structure

64 to 66

excitation structures

71

section

81

security structure

91

color change

92

differences

93

Part of the security structure

101 to 104

arrows

120

cover

130

Booklet

131 to 138

book page

141, 142

Edges (the book page)

152 to 158

edge strips

160

Got over

161 to 168

(Identification) tags

170

figure

171

missing circle section

201 to 214

pictures

500 to 570

steps

R

back

V

front

M _SA (λ = λ ₁ )

(magnetic) field strength of the structure excitation, which leads to a crystal structure that affects light of wavelength λ ₁

d1

Shift (in the picture)

d2

(relative) displacement (the excitation structure versus the safety structure)

Claims (13)

1. Superposed security element comprising:

   at least one substrate layer (31) and

   a first security structure (81) which is printed using a structure ink, wherein the structure ink comprises microcapsules (10) in which colloidal particles (13) are dispersed in a medium (12) and can be oriented relative to one another by means of an electric field and/or a magnetic field in order to create and/or change a crystal structure (15), wherein distances between the particles (13) are critical to the colour impression of the structure ink, and at least one excitation structure (61) which generates an electric field and/or a magnetic field, wherein the at least one excitation structure (61) is formed spatially separate from the security structure (81) on the at least one substrate layer (31) or on at least one further substrate (32;33;35) connected to the at least one substrate layer (31), wherein the arrangement of the security structure (81) and of the excitation structure (61) on the at least one substrate layer (31) or on the at least one substrate layer (31) and the further substrate layer (32;33;35) is configured such that a superposed state can be brought about, in which the security structure (81) and the excitation structure (61) superpose one another in a flat manner, and a non-superposed state can be brought about, in which the excitation structure (61) and the security structure (81) are not superposed in a flat manner, and wherein the excitation structure (61) is designed in such a way that it brings about in the superposed state a change in the optically perceptible colour impression of the security structure (81) compared to the non-superposed state, wherein, in addition to the at least one excitation structure (61) on the at least one substrate layer (31), another excitation structure (63) is formed on the at least one further substrate layer (32), or, in addition to the at least one excitation structure (61) on the at least one further substrate layer (32), the at least one other excitation structure (63; 64-66) is formed on still another substrate layer (33;35) connected to the at least one substrate layer (31), wherein the at least one other excitation structure (63) generates an electrical field and/or magnetic field and likewise can be superposed with the security structure (81), such that this at least one other excitation structure, at the superposing by the security structure (81), exerts an effect on a change, caused by this at least one other excitation structure, in the optically perceptible colour impression of the security structure (81).
2. Superposed security element according to claim 1, characterised in that the at least one excitation structure (61) comprises permanently magnetic materials.
3. Superposed security element according to claim 1 or 2, characterised in that the at least one excitation structure (61) is structured laterally.
4. Superposed security element according to any one of the preceding claims, characterised in that the structure ink of the security structure (81) is structured laterally.
5. Superposed security element according to any one of claims 1-3, characterised in that the structure ink of the security structure (81) is configured with a homogeneous surface.
6. Superposed security element according to any one of the preceding claims, characterised in that the at least one substrate layer (31) is a booklet page (131) or a constituent part of a booklet page (131), and the at least one further substrate layer (32) is a further booklet page (132) or a constituent part of the further booklet page (132) and, if applicable, the at least one still further substrate layer (33;35) is a still further booklet page (133; 135) or a constituent part of the still further booklet page (133; 135), and the one booklet page (131) and the at least one further booklet page (132) and, if applicable, the at least one still further booklet page (133; 135) are gathered together into a booklet (130).
7. Superposed security element according to claim 6, characterised in that the material of the one substrate layer (31) and, inasmuch as other substrate layers are gathered together with the one substrate layer (31) to form the one booklet page (131), the material of these other substrate layers are transparent to light in the visible wavelength range, such that the security structure (81) formed by the structure ink is optically perceptible through both opposing surfaces of the one booklet page (131).
8. Superposed security element according to any one of the preceding claims, characterised in that the security structure (81) and the at least one excitation structure (61), as well as the at least one other excitation structure (63) are configured and arranged in such a way that the security structure can superpose the at least one excitation structure (61) and the at least one other excitation structure (63) can simultaneously superpose on a common surface, such that the changes which are caused by the at least one excitation structure (61) and the at least one other excitation structure (63) of the optically perceptible colour impression of the security structure (81) can be perceived in relation to the non-superposed state in superposed image.
9. Method for verifying a superposed feature of a superposed security element according to any one of claims 1 to 8, wherein the superposed feature is a security structure (81), which is printed by means of a structure ink on a substrate layer, wherein the structure ink comprises microcapsules (10) in which colloidal particles are dispersed in a medium, which can be oriented relative to one another by means of an electrical field and/or a magnetic field in order to create and/or change a crystal structure, wherein distances between the particles are critical to the colour impression of the structure ink, and comprises an excitation structure (61) which is formed spatially separate from the security structure (81) on the at least one substrate layer (31) or on at least one further substrate (32;33;35) connected to the at least one substrate layer (31), and which generates an electrical field and/or magnetic field, comprising the steps:

   Bringing about a superposed state between the security structure (81) and the excitation structure (61) in such a way that they superpose one another in a flat manner;

   formation of a superposed image of the security structure (81) in the superposed state;

   and bringing about of a non-superposed state, in which the security structure (81) and the excitation structure (61) do not superpose in a flat manner,

   formation of a comparison image of the security structure (81) in the non-superposed state;

   comparing the superposed image (203) and the comparison image (202) and appraising differences (92), and

   verification of the superposed feature on the basis of the appraised differences (92) in relation to expected differences, wherein the security structure (81) in the one superposed state, in addition to the at least one excitation structure (61) also superposes at least one other excitation structure (63), or the security structure (81) in the non-superposed state, in which the security structure (81) and the excitation structure (61) do not superpose in a flat manner, is arranged in such a way that the security structure (81) superposes in a flat manner the at least one other excitation structure (63), which generates an electric field and/or magnetic field, and, at the verification, account is taken as to whether the appraised differences are affected at least by the at least one other excitation structure (63).
10. Method according to claim 9, characterised in that the superposed feature is verified with a booklet page (131), in that the booklet page (131), which is formed from the substrate layer (31) onto which the security structure (81) is printed, is opened out such that the booklet (131) superposes the further booklet page (133), which comprises the further substrate layer (33) on which the excitation structure (61) is formed, and the superposed image (203; 213) is then appraised in this manner.
11. Method according to claim 9 or 10, characterised in that a lateral position of the security structure (81) is changed relative to the at least one excitation structure (61) in the superposed state, and a further superposed image (204) is appraised, and deviations between the superposed image (203) and the further superposed image (204) are detected, and the superposed feature is only verified as authentic if the deviations detected correspond to expected deviations.
12. Method according to any one of claims 9 to 11, characterised in that an item of information represented by the differences (92) is isolated and compared with an expected item of information, and the superposed feature is only verified as authentic if the isolated item of information corresponds to the expected item of information.
13. Method according to any one of claims 10 to 12, characterised in that the non-superposed state is produced as an alternative superposed state, in which, starting from the superposed state, the booklet page (131), which comprises the substrate layer (31) onto which the security structure (81) is printed, and of which a surface is appraised during the appraisal of the superposed image (210), is turned over, and, at the appraisal of the comparison image, the opposite surface of the booklet page (131) is appraised as an alternative superposed image (213).

Images