EP2769364B1 - Method for verifying a security document having a visual barrier, using a display device - Google Patents

Description

The invention relates to a method for the verification of security documents with which security documents can be reliably tested for their authenticity and / or integrity. In particular, the invention relates to a method for verifying security documents which comprise a visual barrier which allows for a viewing through the security barrier and the security document for at least one viewing geometry.
Security features are understood to mean all features which make it impossible or at least significantly complicate the imitation, falsification, duplication or unauthorized production of an object. A document which has at least one security feature is called a security document. Security documents include, for example, identity documents such as identity cards, passports, identification cards, access cards, but also driving licenses, visas or documents of value such as banknotes, securities, postage stamps, customs stamps and the like, to list only a few. Also, seals and labels for authentication of the authenticity of products or security features protected against counterfeiting or falsification security features and the like are considered as security documents. Both a material texture, a combination of different materials, a special printing, an introduction of diffractive, reflective structures and the like can be used as security features. Other security features may be formed, for example, by means of an integrated microchip, a magnetic stripe, or other materials having certain physical or chemical properties, such as a luminescent characteristic or the like.
An essential function of security features is to offer a possibility to determine a genuineness and / or authenticity of the security feature itself as well as of the security document in which the corresponding security feature is integrated. Such a procedure is called verification. Here, the authenticity and / or integrity of the security feature and / or the security document is checked. In addition to verification of the authenticity and / or integrity of a security document, individual security features, In particular, those in which information is stored can be used to perform a higher level verification of the security document or control of a person associated with the security document. A simple example of this is, for example, a serial number integrated in a passport, which can be used after a read-out in order to determine via a comparison with a database in which stolen passports are registered, whether the pass which is being verified, belongs to the stolen reported passes or not. It is understood by those skilled in the art that more complex verification measures or more complex features can be used for such verifications.

Security documents are known from the prior art, which include security features that show different graphical images under different viewing geometries. Different imaging geometries may, for example, be defined by different viewing directions relative to a direction associated with and associated with the security document. For example, in a substantially planar security document, a surface normal to the security document may be set as the reference direction with respect to which the viewing directions of the security document are defined. For example, security features are known, which are also referred to as tilt images, which disclose different information under different viewing directions. Such security features can be implemented differently. For example, holograms or other diffractive structures can be used for this purpose. Other embodiments use microlenses, for example, which image different information portions stored in the document under different viewing directions. Such security features are also referred to in the art as CLI (Changeable Laser Image) or MLI (Multiple Laser Image) features. Other security features use so-called parallax barriers in which individual areas of information are obscured by the viewing barrier, which is spaced from the stored information and located in front of the stored information with respect to the viewing direction.

In the WO 2006/018171 A2 and the DE 10 2004 051 919 A1 are a security element for securing security papers, documents of value and the like with a transparent carrier known. The transparent carrier is with a Provided authenticity mark that conveys a first visual impression in transmitted light and conveys a second optical impression in reflected light in front of a specific and easily accessible background, which differs significantly from the first visual impression.

In general, there is a need to provide new and / or improved security features as well as new and / or improved verification methods for security features and security documents having these security features.

Features which can be read out by a human person without the aid of further technical aids from the security document or can be checked directly for their authenticity and authenticity are referred to as so-called Level 1 security features. Features requiring technical aids for review are referred to as Level 2 features. The object of the invention is therefore to provide a verification method and a verification system, with which an improved verification by exploiting widespread objects is possible.

Basic idea of the invention

The invention is based on the idea to display graphical information on a display device and to arrange a value and / or security document in front of the display area. Subsequently, at least two graphic images are recorded for different viewing geometries and the graphic images are evaluated and from this a verification decision is derived.

definitions

A security feature is a feature that makes it difficult or impossible, or at least makes its manipulation recognizable, an imitation, falsification or unauthorized production of an object in which the security feature is incorporated or in which this is formed.

A see-through security feature is a security feature that has one or more transparent or translucent areas. A captured graphic image of the transparent or translucent areas is thus dependent on what is on the side facing away from the viewer of the see-through security feature. Security documents are all those documents that include at least one security feature, typically a variety of security features.

Security documents include, for example, personal documents such as passports, identity cards, access cards, identification cards, driving licenses, but also bank cards, credit cards, visas or the like, just to name a few.

Security documents, which additionally embody a value, are also referred to as value documents. Security documents, which at the same time represent value documents, are, for example, banknotes, postage stamps, securities, entry tickets secured with security features or the like. A precise delimitation of the subgroup of value documents is sometimes difficult. In terms of what is described here, such delineation does not matter. All value documents are also security documents according to the definition given here.

A display device in the sense of what is described here is a device which can generate a graphic representation on a display surface. In this case, the display device is designed so that different information contents can be displayed one after the other at the same presentation positions. Such a display device is also referred to as a freely programmable display area, since the information content, which is displayed at a display position, can be selected freely, for example via program-controlled image data generation. Television screens but also computer screens, matrix-like LCD, TFT screens or the like are display device in the sense of what is described here. Further, visualizers of cell phones, personal digital assistants (PDAs) or similar are display devices as described herein.

As a visual barrier, each structural unit of a security document is understood, which selectively releases different information components for different viewing geometries, which are arranged, formed or displayed on a side of the visual barrier facing away from the viewer or a detection unit. A visual barrier may for example consist of a microlens array, wherein the microlenses do not necessarily have to be formed with an identical focal length and / or orientation of their optical axis. A visual barrier may also be in the form of a pattern of transparent or translucent areas on the one hand and opaque areas on the other. For example, other visual barriers may be at different angles to a surface normal of a plane Layer formed channels may be formed in the form of through-hole, wherein the layer itself is opaque.

A partial image part is a part of an information which is combined with a further partial image part into an overall image, i. H. to complete information. Partial image portions can be, for example, graphic representations of information that can be perceived when viewed through an eye of a human being. Since a perception of a near object by another eye of the same observer takes place from a different position, the parts of the field which are perceived by both eyes of the human observer simultaneously from the same information differ. Thus, two such sub-image portions can complement each other to an overall image, which causes a three-dimensional image impression in a human observer, if the object under consideration is three-dimensional. However, partial image portions can also have completely different information contents, which complement each other to form a total information which can then be graphically recorded. For example, a first subpicture may have seemingly indiscriminately arranged black image areas in front of a monochrome, for example, white background, and a second subpicture also have seemingly randomly arranged black image areas in front of the same background, but complement each other in such a way that in the complement they appear to be random arranged black area represent a total information, which represents, for example, alphanumeric characters or symbols that are easily detectable and represent information coding that can be evaluated in a simple manner for a human observer or for a machine evaluation.

An imaging geometry or viewing geometry may, for example, be characterized by a direction under which a security document is viewed or detected. For example, a viewing direction may be defined as the optical axis of camera imaging optics relative to a surface normal of the viewed object. This means that a viewing or graphic detection of an object from different directions represents a detection under different viewing geometries. A detection of an object from the same viewing direction, but from different distances represents a capture of two images under different imaging geometries. It is understood that combinations of these are possible.

By color mixing is meant a color addition and a color subtraction. If light of different wavelengths, i. H. different colors, superimposed, so often results for a human observer, a color impression that differs from the color impressions that cause the different wavelengths in a separate consideration. This process is called color addition. An image constructed of different colored pixels that no longer resolves a human eye separately also often causes a color impression to the viewer, which differs from the color impressions that the individual pixels or print pixels have in a human viewing Invoke observers. If an image is composed of different body colors, then the mixture is called color subtraction.

Preferred embodiments

A method for verifying a value or security document is proposed, comprising the steps of: operating a display device, on the display surface of which a graphical representation is displayed, arranging a security document in front of a display area with the illustrated graphical representation (in particular placing the security document on the display area ), wherein the security document comprises a security feature with a visual barrier which, when viewing or capturing an image in view for different viewing geometries, in particular different viewing directions and / or viewing distances or detection directions and / or detection distances, releases different information portions located behind the visual barrier, wherein the visual barrier is integrated into the security document in such a way that, at least for one viewing geometry, a view through the visual barrier u the security document is possible to an information component located behind the security document, wherein the graphical representation comprises at least a first partial image portion for the at least one viewing geometry, capturing at least two images of the security document mounted in front of the display device for at least two different viewing geometries, evaluating the captured at least two figures and derivation of a verification decision. The advantage of the invention is that with widely available display devices, such as for example can be verified by personal computers, personal digital assistants or mobile telephones, especially those designated as smartphones mobile phones. The invention also has the advantage that novel security features are easily verifiable.

The invention is described by the features of independent claim 1. According to one aspect of the invention, it is provided that a homogeneously monochromatically formed first partial image component is displayed on the screen, which produces a first color impression, and at least a second partial image component is represented, which is homogeneously monochrome and causes a second color impression different from the first color impression , and it is checked in the evaluation whether a monochrome color impression is produced in a human observer when viewed through the visual barrier, which is different from the first and the second color impression. This allows easy and reliable verification. According to one aspect of the invention, it is checked whether different partial images causing monochrome color impressions can be added to form an overall image which causes a deviating homogeneous monochrome color impression in the viewer in the overall picture. In one embodiment, it is thus checked whether color perception is caused in a human being caused by a color mixing of the at least one partial image component and the at least one second partial image component and the color perception of the overall image of that of the at least one partial image and the at least one second partial image different.
In a preferred embodiment, the at least two images for different viewing directions are detected. By a human user this is done, for example, by a simple look with both eyes. Since these are spaced apart, consider the two eyes that in front of the display area the display device arranged security document under different viewing directions. An evaluation and verification can thus be perceived directly by a human observer in a simple manner. However, it is of course also possible to detect the different images by two cameras spaced apart from one another, for example digital cameras, and to evaluate the recorded graphic images with an evaluation device, for example in the form of a program-controlled microprocessor device, and to make them based on the evaluation of a verification decision.

Another embodiment according to one aspect of the invention provides that the at least two images from different distances are detected by the security document. In one embodiment, it is provided that at least one second partial image portion is stored in the security document, which can be perceived through at least one of the at least one viewing geometry, for example the different viewing geometry, for example different viewing directions, and at least one of the at least one viewing geometry two pictures a supplement of the partial picture parts to an overall picture is examined. For example, it can be checked whether alphanumeric characters or simple graphic symbols that are not completely contained in the partial image portions can be detected in the overall image. In another embodiment, it is provided that at least one second partial image component is displayed on the display surface in addition to the at least one partial image component and it is checked during the evaluation of the at least two images as to whether the images in each case comprise the first or the second partial image component in such a way that that these add up to an overall picture. In this embodiment, the two pieces of information that the user perceives are both displayed on the display surface so that they are "rendered" perceptible by the visual barrier of the security document into separate viewing geometries, such that overlaying the sub-images gives an overall picture.

According to one aspect of the invention, which may be implemented individually or in combination with other aspects of the invention, the sub-images are arranged to produce a 3D effect on a human observer with excellent viewing geometries for the at least two images. Here, the first partial image portion displayed on the display surface and the second partial image portion either displayed on the display surface or be formed in the security document itself.

The partial image information or partial image information which is displayed on the display surface must therefore be adapted to the visual barrier and optionally additionally to a partial image component which is formed in the security document.

Therefore, in one embodiment, according to one of the aspects of the invention, it is provided that an identifier is detected and the graphical representation on which the display area is retrieved from a memory, for example a database, or generated mathematically on the basis of the identifier as a function of the identifier. This creates the possibility of being able to check a large number of different security documents, for which individually different graphic representations are required on the display area. Other embodiments of security documents can be designed such that they can each be verified with the same graphical representation on the display area.

In a development of the aspects according to the invention, it can be provided that the verification should only be possible if a person who is assigned to the security document agrees to this verification. This is for example possible because in addition to the identifier, a PIN is detected and retrieval and / or generating the graphical representation is only possible if the identifier and the associated PIN have been detected and verified as belonging together correctly.

In an embodiment according to one of the aspects of the invention, it is checked whether it is perceptible to a human observer an expected image impression, which results from the superimposition of the one partial image portion with the further partial image portion or second partial image proportion, which differs from the viewing geometry deviating from the one viewing geometry the visual barrier is perceptible.

In one embodiment of one of the aspects of the invention, it is checked whether personal information is present in one of the two images or in the resulting overall image. Personal information is information that is personalized to a person to whom the security document is associated characterize. Personalizing information may be, for example, a name, a date of birth, an address or the like.

In some embodiments, such personalizing information is stored in the visual barrier of the security document, and is perceivable when the security document is viewed in front of the display area, as long as the graphical representation on the display surface is adapted to the visual barrier and possibly to the image portions stored in the first security document becomes. Likewise, it is possible for information on the display surface to be perceptible when viewed or mapped without a security document disposed in front of it, but obscured by the visual barrier, although a resulting overall image does not appear to encompass covered image areas. This is possible, for example, with a visual barrier comprising microlenses. Under certain viewing geometries, individual components of information for particular viewing directions are selectively "not displayed" and instead, other information components are mapped. In other embodiments, when viewed through the viewing barrier, information portions disposed on the display area in the graphical representation are "scattered" to depict information that is graphically captured by a human viewer, such as alphanumeric characters or simple graphical symbols.

In order to obtain a suitable complement to an overall picture, a relative arrangement of the security document and hereby the visual barrier relative to the graphical representation and the respective viewing geometries from each other is necessary. Therefore, it is provided in one embodiment that the representation of the at least one partial image portion and / or the at least second partial image component is anchored on the display surface or be and multiple imaging pairs are evaluated. A positive verification decision is made, for example, if an expected addition of the partial image portions to an overall picture is successfully possible for one of the image pairs. Such a successful completion takes place, for example, when a 3D impression is created in a human observer.

Alternatively or in addition to the variation of the at least one partial image or of the at least one partial image or the at least second partial image on the display in one embodiment, the arrangement of the security document in front of the display area varies and the at least two images evaluated at least in pairs, wherein each evaluated at least in pairs of at least two images, such images are the same time or at least for the same orientation of the security document relative to the same representation on the Display area and the at least two mutually different viewing geometries are detected. It is also possible, alternatively or additionally, to vary the viewing geometries, for example by changing a viewing distance which in a human observer is accompanied by a viewing direction change for the perceived images in the eyes.

Fig. 1

eine schematische Darstellung zur Erläuterung eines Verifikationsablaufs;

Fig. 2

eine weitere Ausführungsform zur Veranschaulichung eines weiteren Verifikationsablaufs;

Fig. 3

eine schematische Darstellung eines auf eine Anzeigevorrichtung aufgelegten Sicherheitsdokuments, welches eine Sichtbarriere aus gleich beabstandeten transparenten und opaken Streifen ausgebildete Sichtbarriere umfasst;

Fig. 3a

eine schematische Darstellung zur Erläuterung der Wahrnehmung des Sicherheitsdokuments nach Fig. 3 unter einer ersten Betrachtungsrichtung;

Fig. 3b

eine schematische Darstellung zur Erläuterung der Wahrnehmung bei Betrachtung des Sicherheitsdokuments nach Fig. 3 unter einer anderen Betrachtungsrichtung;

Fig. 4

eine schematische Darstellung eines Sicherheitsdokuments, welches auf einer Anzeigefläche angeordnet ist, auf der unterschiedliche Teilbildanteile für ein stereoskopisches Bild dargestellt werden;

Fig. 4a

eine schematische Erläuterung der Wahrnehmung bzw. Abbildungserfassung bei dem Sicherheitsdokument nach Fig. 4;

Fig. 5

eine schematische Darstellung eines Sicherheitsdokuments vor einer Anzeigefläche, bei dem die Sichtbarriere durch Perforationen in dem Sicherheitsdokument ausgebildet ist;

Fig. 6

eine schematische Darstellung eines Sicherheitsdokuments vor einer Anzeigefläche, wobei ein Teilbildanteil eines stereoskopischen Bilds in dem Sicherheitsdokument codiert ist;

Fig. 7

eine schematische Darstellung eines Sicherheitsdokuments" welches als Sichtbarriere ein Mikrolinsenarray mit Mikrolinsen unterschiedlicher Brennweite aufweist;

Fig. 8

eine schematische Darstellung eines Sicherheitsdokuments, welches vor einem Bildschirm angeordnet ist, wobei das Sicherheitsdokument als Sichtbarriere eine Mikrolinsenarray aus Mikrolinsen gleicher Brennweite aufweist.

The invention will be explained in more detail by means of embodiments with reference to figures. Hereby show:

Fig. 1

a schematic representation for explaining a Verifikationsablaufs;

Fig. 2

a further embodiment for illustrating a further Verifikationsablaufs;

Fig. 3

a schematic representation of a placed on a display device security document, which comprises a visual barrier of equally spaced transparent and opaque strips formed visual barrier;

Fig. 3a

a schematic representation for explaining the perception of the security document after Fig. 3 under a first viewing direction;

Fig. 3b

a schematic representation for explaining the perception when looking at the security document after Fig. 3 under another viewing direction;

Fig. 4

a schematic representation of a security document, which is arranged on a display surface on which different partial image portions are displayed for a stereoscopic image;

Fig. 4a

a schematic explanation of the perception or image acquisition in the security document after Fig. 4 ;

Fig. 5

a schematic representation of a security document in front of a display surface, in which the visual barrier is formed by perforations in the security document;

Fig. 6

a schematic representation of a security document in front of a display area, wherein a partial image portion of a stereoscopic image is encoded in the security document;

Fig. 7

a schematic representation of a security document "which has as a visual barrier a microlens array with microlenses of different focal lengths;

Fig. 8

a schematic representation of a security document, which is arranged in front of a screen, wherein the security document as a visual barrier has a microlens array of microlenses of the same focal length.

Based on Fig. 1 It should be explained how a verification of a see-through security feature 2 takes place in cooperation with a display device 4. A security document 1, which in the illustrated embodiment comprises a see-through security feature 2, is arranged in front of a display surface 3 of a display device 4. The display device 4 may be, for example, an ordinary computer screen on which content, for example software-controlled, can be displayed in a targeted manner. However, the display device may also be a display of a mobile phone, a personal digital assistant or a digital camera or the like. For example, a graphic 5 is controlled on the display surface 3 via a computer 5. The graphical representation that can be displayed on the display surface 3 comprises at least a first partial image portion 101 for a verification of the security document 1 or the see-through security feature 2 contained therein. The at least one partial image portion is formed in the form of strips 101-1 in this embodiment. The strips 101-1 can all be formed homogeneously monochrome. In other embodiments, the stripes 101-1 of the frame portion 101 represent strip-like portions of a photographic image or an alphanumeric "text" against a background.

The see-through security feature 2 comprises a visual barrier 210. The visual barrier 210 comprises transparent, for example transparent, in particular color-neutral sections 211 and opaque, opaque sections 212. The transparent sections 211 and the opaque sections 212 are strip-like, alternating in this embodiment. In other embodiments, the geometric configuration of the opaque and transparent sections can be chosen completely differently.

The visual barrier 210 can be produced for example by a partial printing, for example with parallel color stripes 213, on a transparent film which is joined together with other films to form a document body, which are transparent at least in the area of the see-through security feature.

In other embodiments, the visual barrier 210 may be formed by micro-perforations formed, for example, in an inner opaque layer. Preferably, the perforated opaque layer is laminated between further transparent layers in a security document body. In yet another embodiment, the visual barrier is formed by means of a microlens array.

The visual barrier 210 is integrated into the security document 1 in such a way that, under a viewing direction through the visual barrier 210 and the security document 1, it is possible to view information or graphically record information that is displayed behind the security document. Furthermore, the visual barrier is designed such that at least one viewing direction exists under which this information component can be perceived through the visual barrier 210 and the security document 1 and an alternating viewing direction exists by which this information component can not be perceived or at least not completely perceived. The visual barrier thus causes view angle dependent arranged behind the security document Information through the security document and the visual barrier can be perceived or can not be perceived.

If the security document 1 is arranged in front of the display surface 3, the detectable graphic image of the see-through security feature 2 is influenced by the viewing angle as a function of the first partial image portion 101 in the area of the transparent security feature 2 and the visual barrier 210 shown on the display area. During verification, at least two images are thus detected, which are formed from the "overlaying" of the first partial image portion 101 shown on the display surface 3 and the visual barrier 210 formed in the security feature 2. By means of a suitable choice of the graphical representation of the first partial image portion 101, adapted to the security document 1 to be verified or its see-through security feature 2, different overall graphic images of the security document 1 or the transparent security feature 2 can be perceived in front of the display surface 3. The captured images, which are detected, for example, with a camera (not shown) in succession or with two cameras (not shown) spaced apart, are evaluated in a downstream evaluation device, for example the computer 5, in order to make a verification decision.

In simple verification systems, the first partial image portion 101, which is displayed on the display surface 3 of the display device 4, regardless of the verifiable security document 1 and its see-through security feature 2 in the sense that the same on the display surface 3 shown first partial image portion 101, for example a regular monochrome line grid, for a variety or all security documents 2 can be used to derive from the resulting images of the security document 1 in front of the display surface 3, the verification decision can. For example, it can be checked whether the first partial image portion 101 is perceptible in the image acquired under a viewing geometry, in this case a first viewing direction, and is imperceptible in a captured image under a viewing geometry deviating from the one viewing geometry, here a different viewing direction is.

For a verification decision, however, it is not the perceptibility and non-perceptibility of the same information that will be decisive in the eye; Check whether the information contents of the two figures, which are perceptible under different viewing geometries, make sense.

Preferably, on the display surface 3 of the display device 4, in addition to the first partial image portion 101, a second partial image portion 102 is shown graphically. The second partial image portion 102 is also formed strip-shaped, wherein the strips 101-1 of the first partial image portion are arranged alternately with strips 102-1 of the second partial image portion 102 on the display surface. The arrangement is adapted to the visual barrier 210 of the security document 1, which is to be verified with this graphical representation on the display surface 3. Given a suitable relative arrangement of the security document 1 in front of the display surface 3 and a capture of the images under suitable viewing directions, the partial image portions 101 and 102 which are perceptible in the two captured images represent partial images that lead to a three-dimensional image impression in a human, provided that Images are each separately "fed" to one of the eyes of a person. Thus, if a human being at a suitable distance from the security document 1 views the see-through security feature 2 while the security document 1 is arranged in front of the display surface 3, he or she can perceive a three-dimensional image as long as the partial image information portions 101, 102 are suitably adapted to the visual barrier 210. It is understood that in particular in visual barriers, in which the opaque portions 212 and the transparent portions 211 represent other geometric configurations, in particular irregular or not regularly appearing patterns, a 3D image perception is only possible if the corresponding partial image portions suitable to Visual barrier are adjusted. Thus, a high verification accuracy can be achieved.

A higher level of verification security is obtained with a system which is in Fig. 2 is shown schematically. In this system, the first partial image portion 101 or are the partial image portions 101, 102 shown on the display surface 3 of the display device 4 depending on an identifier 10, which is assigned to the security document 1. In the example shown, a serial number 11 is used as identifier 10. The identifier 10 is detected by a detection device 12. The detection can be optical, magnetic, electronic, for example via a wireless communication from a microchip (not shown). Likewise, the detection device 12 may also be a keyboard via which an input of the serial number is detected.

If necessary, an additional personal identification number (PIN) 17 can be recorded. The identifier 10 and optionally the PIN 17 are used to retrieve a graphical information associated with the identifier 10 from a database 13, or to calculate using an algorithm, which is implemented for example in the computer 5 by means of a program code. On the display surface 3, a first partial image portion 101 and a second partial image portion 102 are displayed here. In front of the display surface 3, as in the embodiment after Fig. 1 the security document 1, which comprises a see-through security feature 2 with a visual barrier 210, arranged. Subsequently, the at least two images for different viewing geometries are detected, which capture at least part of the see-through security feature 2 in transmitted light. The captured image are detected, for example, by means of a camera 14 and evaluated in the computer 5 or viewed by a user 6, who evaluates the optically detected image and derives a verification decision. The verification and derivation of the verification decision can be made via a comparison with specifications 15, 16, which are shown schematically with the associated verification decisions in Fig. 2 are shown. The evaluation can also be done in the computer 5.

The operation of a visual barrier is schematically based on the Figures 3, 3a and 3b explained. In Fig. 3 schematically a security document 1 is shown, which comprises, for example, on a front side 220 formed of opaque, spaced from each other arranged color strips 213 visual barrier 210. In other embodiments, a visual barrier formed in this way can also be formed in the interior of the security document 1. Otherwise, the security document 1 is transparent and color-neutral in the illustrated embodiment. This means that light of all wavelengths in the visible wavelength range can pass through the security document with almost no attenuation or at least without any attenuation, or at least, however, this wavelength-independent attenuation. Only the color stripes 213 are designed such that they preferably completely absorb light in the visible wavelength range. The security document 1 is arranged for verification in front of a display surface 3 of a display device 4. On the display surface 3, a first partial image portion 101 and a second partial image portion 102 are shown, which are formed of alternately nested strips 101-1, 102-1. The stripes 101-1 of the first partial image portion 101 are formed homogeneously red and the stripes 102-1 of the second partial image portion 102 are homogeneously green. As in Fig. 3a shown When viewed perpendicularly to the front side 220 of the security document 1, only green light passes through the transparent or transparent portions 211. The red light is absorbed by the color stripes 213 and can not be detected by a first image in the vertical viewing direction. In Fig. 3b It is shown which light components are perceptible from the display surface 3 when viewed at 45 ° with respect to the surface of the front side through the visual barrier 210 and the security document 1. Only red light passes through the transparent portion 211, whereas green light is absorbed by the color stripes 213. Different information portions of the graphical representation on the display surface 3 are thus perceived under different viewing directions, so that different images are produced which can be used in a common evaluation to derive a verification decision. If the partial image portions 101, 102 and the visual barrier 210 are formed such that a viewer no longer resolves the strips of the individual partial image portions at a predetermined distance, in which he or she views the security document at 90 ° and 45 ° with his eyes, he / she assumes the color addition true a yellow area. The 90 ° angles are chosen for illustrative purposes only and differ from the angles chosen for practical implementation.

The in the FIGS. 4 and 4a illustrated embodiment of the security document 1 and the graphical representation on the display surface 3 is similar to the Fig. 3 , In this embodiment, the stripes 101-1 of the first sub-image portion 101 and the stripes 102-1 of the second sub-image portion 102 are each strips of sub-images which, when suitably superimposed, produce a three-dimensional representation of the information contained in the sub-image portions 101, 102 in a human observer. The visual barrier 210 formed in the security document 1 ensures that either only the stripes 101-1 of the first partial image portion 101 or the stripes 102-1 of the second partial image portion 102 can be perceived under different viewing directions. At a suitable distance in front of the security document, the correct orientation of the security document relative to the graphical representation on the display surface 3 by suitably arranged detection devices, such as cameras, or by human eyes, respectively the sub-images are separately detected. A human observer perceives a three-dimensional image in such a case.

In Fig. 4a this situation is shown schematically. The left eye 231 perceives only the first partial image portion and the right eye 232 only the second partial image component 102 true.

In Fig. 5 an alternative embodiment is shown in which the visual barrier 210 is formed by perforations 241, for example micro perforations in an otherwise opaque security document. Again, under suitable viewing directions, only the parts of the field that are separated from one another can be perceived or detected. In order to obtain a correct orientation of the security document relative to the graphical representation on the display surface, for example, the security document can be moved relative to the display surface and temporally successive images are detected, which are then evaluated in pairs. In the evaluation, it is checked whether a 3D impression is caused in an arrangement. Alternatively or additionally, the graphical representation can be varied on the display surface in order to achieve an adaptation to the respective security document or the visual barrier contained therein and / or the orientation of the security document relative to the display surface 3. Of course, these described variations are also useful and applicable in the case of the different visual barriers.

In Fig. 6 an embodiment is shown in which a partial image portion 102, which can be supplemented to form a three-dimensional overall image in the security document 1 spaced from the visual barrier 210 is formed and stored. The additional field part 101 necessary for supplementing is then displayed on the display surface 3, so that when the security document 1 is positioned in front of the display surface 3 under one viewing direction the partial image portion 102 stored in the security document 1 1 and under another viewing direction the partial image portion 101 shown on the display surface 3 are perceptible. The verification decision can be made dependent, for example, on whether the partial image component 101 displayed on the display surface is supplemented with partial image component 102 stored in the security document in such a way that a three-dimensional perception is produced by the user. Likewise, however, it is also possible to check whether a suitable mixed color is perceived, which is caused, for example, by homogeneously monochromatic sub-image components in a human observer, provided that the sub-image components are interlaced with one another by their geometrical dimensions so that the viewer can see the individual geometric configurations of the transparent and opaque sections does not dissolve, but the perceived from the two perceived by the different parts of the field parts overall representation perceives as a total information.

In Fig. 7 schematically another embodiment is shown, in which the visual barrier is formed by microlenses. In the illustrated embodiment, the viewing barrier comprises a microlens array 300 including first microlenses 301 having a first focal length 305 and second microlenses 302 having a second focal length 306 different from the first focal length. In the illustrated embodiment, the first and the second microlenses 301, 302, which are for example cylindrical lenses, are arranged alternately. These form under a first viewing direction different partial image portions 101, 102, which are shown on the display surface 3 of a display device 4, in different image planes 303, 304 from. Thus, images captured at different distances can perceive different information contents and can be used to derive the verification decision. In addition, microlenses form different areas of the display area under different viewing directions, so that a viewing angle dependence is also present. In a suitable embodiment, partial image portions which are shown on the display surface are also perceived in this embodiment in such a way that a three-dimensional image impression is produced by a viewer.

In one embodiment, it is provided that it is checked whether a color perception is caused in a person, which is caused by a color mixing of the at least one partial image portion (101) and the at least one second partial image portion (102) and the color perception of the overall image of the distinguishes at least one field part (101) and the at least one second field part.

In Fig. 8 an embodiment is shown in which again a partial image portion of the information is stored in the security document. The security document 1 comprises a microlens array 300 in which the microlenses 301 all have the same focal length 305. In this embodiment, the different partial image portions, the partial image portion 101 displayed on the display surface, and the partial image portion 102 stored in the security document 1 become different levels sharply imaged, since the information portions, ie the sub-picture portions 101, 102 are arranged at different distances to the microlenses.
In other embodiments, the microlenses may be configured to image information perceivable on the display surface when viewed without the security document placed in front of the display surface when the security document is placed in front of the display surface so that it is no longer perceptible, but instead uniformly monochrome surface is perceived. Thus, under a viewing direction, the pieces of information carrying, for example, alphanumeric information are mapped in directions that do not coincide with the one viewing direction. Instead, information portions of the background for "populating" the areas where the alphanumeric information is displayed on the display area are imaged for perception from the one viewing direction. In another embodiment, the microlenses are formed such that a seemingly random pattern is imaged by the microlenses so that, for example, alphanumeric information is perceptible.
It is understood by those skilled in the art that only exemplary embodiments of visual barriers are described here.

LIST OF REFERENCE NUMBERS

1

The security document

2

Through security feature

3

display area

4

display device

5

computer

6

user

10

ID

11

serial number

12

detection device

13

Database

14

camera

15, 16

Requirements

17

pin code

101

first field part

101-1

strip

102

second field part

102-1

strip

210

visual barrier

211

transparent sections

212

opaque sections

213

color stripes

220

front

231

left eye

232

right eye

241

perforations

300

microlenses

301

first microlenses

302

second microlenses

303, 304

image planes

305

(first) focal length

306

second focal length

Claims (6)

1. Method for verifying a value document or security document (1), comprising the steps:

   operating a display device (4), the display area (3) of which displays a graphic representation,

   arranging, in front of the display area (3) with the graphic representation, a security document (1), wherein the security document (1) comprises a security feature including a visual barrier (210), that uncovers, when looked at in transmitted light at different viewing geometries, different pieces of information present behind the visual barrier (210), wherein the visual barrier (210) is integrated into the security document (1) such that, for at least one viewing geometry, a view through the visual barrier (210) and through the security document (1) onto a portion of information present behind the security document (1) is possible,

   wherein the graphic representation comprises at least one first partial image portion (101) for the at least one viewing geometry, and wherein, on the display area (3), in addition to the at least one first partial image portion (101), at least one second partial image portion (102) is displayed, wherein the first image portion (101) is represented configured as homogeneous monochrome, which incurs a first colour impression, and the at least one second partial image portion (102) is represented, which is configured as homogeneous monochrome and incurs a second colour impression which is different from the first colour impression,

   detecting at least two images of the security document (1) in front of the display device (4) for at least two different viewing geometries, in that at least one first image is detected for a first viewing geometry and a second image is detected for a second viewing geometry which differs from the first viewing geometry,

   evaluating the at least two images detected, wherein, during the evaluation of the at least two images, a check is made as to whether the images comprise the first and the second partial image portions (101, 102) in such a way that the first image and the second image can be supplemented to form one total image,

   and from the total image, with a human observer, on the basis of a colour mixture, a monochrome colour impression is incurred, which is different from the first and second colour impression, and

   deducing therefrom a verification decision, wherein the verification result is dependent on whether the total image incurs, or not, a monochrome colour impression which differs from the first and the second colour impression.
2. Method according to claim 1, characterised in that the detecting of the images at different viewing geometry takes place, in that the images are detected in different directions of observation.
3. Method according to any one of the preceding claims, characterised in that, on the screen, as first partial image portion (101), a monochrome surface is represented, and as second partial image portion (102), a monochrome surface is represented.
4. Method according to any one of the preceding claims, characterised in that the directions of observation for the appraisal of the at least two images are varied.
5. Method according to any one of the preceding claims, characterised in that the representation of the at least one partial image portion (101) and/or of the at least second partial image portion (102) on the display is varied, and a plurality of image pairs are evaluated.
6. Method according to any one of the preceding claims, characterised in that the arrangement of the security document (1) in front of the display area (3) is varied, and the at least two images detected are evaluated at least in pairs, wherein the respective images evaluated at least in pairs, of the at least two images, are such which are detected simultaneously, or at least with the same orientation of the security document (1) relative to the representation on the display area (3), under the at least two directions of observation, which are different from one another.

Images