Method for producing a security or valuable document, for verifying the authenticity of a security or valuable document, and security or valuable document

Abstract

The invention relates to a method for producing a security or valuable document (20) comprising a data carrier (1) provided with a printed image (12) of a person. To increase the counterfeit protection, at least one image-specific feature (17) is determined from the image (12) after the image of the person has been created. The image feature (17) is incorporated into the data carrier (1) as an electrically conductive structure (18). Furthermore, the invention relates to a corresponding security or valuable document, a verification method for checking the authenticity of such a document, and a test setup (40) for such a verification method.

Description

[0001] The present invention relates to a method for producing a security or valuable document with a data carrier containing a printed image of a person and an image-specific feature. The invention further relates to a security or valuable document with a printed image that is protected against forgery, and to a method for verifying the authenticity of the image printed on the data carrier.

[0002] Security documents such as passports, identity cards, or driver's licenses, as well as personalized valuables like tickets or payment instruments, feature images of the respective person as a security element. During the production of these security documents, the data from the digital or digitized images is processed using the Raster Imaging Process (RIP). The image visible in the security document can be printed in grayscale or with colored inks in the CMYK color model, using the three standardized optimal colors cyan, magenta, yellow, and black.

[0003] To detect manipulation of the images, it is common practice to equip images in security documents with security features, which may, for example, be provided in a zone within the image to be applied.

[0004] Security documents are forged, among other ways, by applying a photograph of another person over the photograph of the document holder, or by altering / manipulating the photograph in such a way that identity theft by another person becomes possible.

[0005] The application of the other person's photograph can be done directly, for example, by printing directly onto the card surface over the actual photograph using inkjet printing, or indirectly, by first printing onto a transfer film and then laminating the image over the actual photograph. Some forgeries leave the other security features, such as luminescent underprinting or kinematic holographic structures (Identigram), largely intact, so that the document appears virtually untampered with or slightly aged.

[0006] Normally, the authenticity of an image can be verified via an electronic component, such as a chip. However, if access to the chip is not possible because the chip has been destroyed or the necessary access rights are lacking, the authenticity of the (personal) image must be verifiable by another means. Therefore, it is desirable that security or valuable documents containing images can also be verified for authenticity without having to access the data stored on the chip.

[0007] EP 3 922 473 A1 describes a method for producing a printed image on a data carrier for a security or valuable document, in which the image is encoded with image-specific results that were previously determined using an algorithm, in particular Canny-Edge detection. The encoding is applied to the image, for example, using a UV-luminescent ink or an infrared-absorbing ink. UV or infrared light sources are required to examine these image features.

[0008] Detecting a forgery depends on the expertise of the person conducting the inspection or on complex, sometimes forensic, methods. Reliable automated, machine-based testing and detection of forgeries in conventional photographs requires sophisticated technical equipment.

[0009] It is therefore the object of the present invention to provide a method for producing data carriers for security or valuable documents with images, which are protected against manipulation even independently of the functionality of a chip and can be tested using common technical means, to provide a security feature for such security and valuable documents, and to provide a method for detecting manipulations of the security and valuable documents that can be carried out in a simple manner.

[0010] Furthermore, it is an object of the invention to create an individualizable, in particular personalizable, security feature that is cost-effective, simple and quick to implement.

[0011] The problem is solved by the features of the independent patent claims. Further advantageous embodiments are the subject of the description, the figures, and the dependent patent claims.

[0012] According to a first aspect of the invention, the method for producing a security or valuable document with a data carrier bearing a printed image comprises providing the data carrier and creating an image of a person. At least one image-specific feature is determined from the image. Before or after printing the image, the image features are incorporated as an electrically conductive structure.

[0013] In this context, an image-specific feature is understood to be an image generated based on the corresponding image. Within the scope of the invention, the image feature can be formed based on image-specific results that can be determined from the respective image or portrait, such as the contours of a face, the position of individual, specific points of a face, or even the clothing, jewelry, etc., of the data carrier owner visible in the image, or other specific results (landmarks) calculated from the color or brightness contrasts of the image or individual areas of the image, which can be uniquely calculated from the printed and / or the data of the digitized image by means of a specific algorithm.

[0014] At least one image feature in the form of an electrically conductive structure can be applied to a substrate layer of the data carrier that corresponds to that of the image, or to a separate substrate layer. The electrically conductive structure can, as further described, be applied to the image area before printing the image, printed together with the image, or incorporated into the printed image.

[0015] In this context, "incorporation" refers to the integration of at least one image feature(s) into the data carrier and / or into the image.

[0016] The image of the person may preferably be a photograph of the person. Alternatively, the image may be a representation of a biometric feature of the person, for example, a fingerprint, a retina, or an iris. The image may preferably be a biometric image, in particular a biometric portrait and / or a biometric passport photo (photograph).

[0017] The visible image can be printed in the usual way using colored inks.

[0018] In this context, "data carrier" refers to a carrier card that may have one or more substrate layers with data printed on it or otherwise applied or stored. The data carrier may, for example, include a wirelessly transmitting chip (RFID) or a chip with external contact pads for identification purposes. The chip may contain image data representing the person. The image of the person stored on the chip may have a different resolution than the image printed on the data carrier, in particular a lower resolution.

[0019] Insofar as the terms "individualized" and "individualizing" are used below, they refer to a property of a security or value document according to which the document can be assigned to a subject with certain characteristics, which, however, do not necessarily allow for a clear assignment to a specific person, such as information about the person's facial contour or eye color.

[0020] In the following text, the terms "personalized" and "personalizing" refer to the property of a valuable or security document that makes it attributable to a specific person. A valuable or security document can also be personalized by a variety of individualizing information if, in combination, this information allows it to be attributed to a specific person.

[0021] Personalization can be achieved in particular by means of biometric features, for example by means of facial features or fingerprints.

[0022] According to a preferred embodiment of a method according to the invention, the data carrier can be personalized by means of the electrically conductive structure. Preferably, the data carrier is personalized biometrically. In this way, the quality of automated authentication can be significantly improved.

[0023] In this context, biometric personalization refers to personalization designed for the evaluation of biometric characteristics, particularly for automated evaluation. For example, simply printing any portrait of a person on a valuable or security document does not always result in personalization that can be reliably evaluated for biometric authentication. In contrast, a biometric passport photo that meets the criteria of the ICAO (International Civil Aviation Organization) ensures reliable evaluation.

[0024] Biometric personalization using the image-specific feature can be achieved in particular by determining the image-specific feature on the basis of a biometric image, e.g. a biometric passport photo, and / or on the basis of the depiction of a biometric feature.

[0025] The image features are represented using at least one electrically conductive structure. Accordingly, biometric personalization can be achieved by embedding this electrically conductive structure in the data carrier.

[0026] The electrically conductive structure can be prefabricated and connected to or embedded in the data carrier. Preferably, the electrically conductive structure is printed onto a substrate layer to reduce the effort required for personalization.

[0027] In a further preferred embodiment of the invention, the conductive structure is applied to a substrate layer that is subsequently concealed. In this way, the electrically conductive structure is protected against mechanical damage. Furthermore, the structure is not accessible without causing significant damage to the data carrier, thus making manipulation more difficult.

[0028] The printing of at least one electrically conductive structure onto a designated substrate layer of the data carrier can take place before or after joining it with further layers of the data carrier.

[0029] Printing can be carried out using a contact printing process, such as screen printing, engraved printing, flexographic printing, or offset printing. Preferably, the introduction of the electrically conductive structure, i.e., the printing of the electrically conductive structure onto the data carrier or onto a layer of the data carrier with the image-specific feature, can be achieved by dispensing. Dispensing, in this context, refers to the high-precision application of a fluid, for example, using a cannula or dispensing head designed for this purpose. The fluid can, for example, contain nanoscale silver particles to create the conductivity. In this way, conductive structures with high conductivity and simultaneously very fine resolution can be advantageously produced. For example, the conductive structures can have a minimum width of less than 10 micrometers.

[0030] The conductive structure can be created using conductive particles that are applied to the data carrier with a binder. For example, conductive metal particles can be applied using a binder.

[0031] According to further preferred embodiments of the invention, the conductive structure can be introduced using a contactless printing method, e.g. using an aerosol jet method or a piezo jet method.

[0032] In preferred embodiments of the invention, printing is carried out using an inkjet printer. Printing with an inkjet printer is advantageous because it allows the personalized image feature to be applied to the document quickly and easily. A large number of documents can be personalized quickly, cost-effectively, and efficiently.

[0033] Electrically conductive ink can be used for printing, as described, for example, in WO 2018 / 162926 A1 and WO 2024 / 208505 A1. To achieve conductivity, the ink can contain conductive particles, especially nanoparticles and / or a conductive polymer. For example, conductivity can be achieved using silver nanoparticles.

[0034] The image feature, or the electrically conductive structure, can preferably be produced in a way that is not visible to the viewer, in particular by being translucent, transparent, the same color as the background, and / or concealed. In this way, the electrically conductive structure can be integrated into the visible image of the person and / or printed together with it, while the original image remains visually perceptible and / or unchanged to the viewer. Furthermore, the electrically conductive structure or image feature is not readily apparent, which makes it more difficult to imitate the image feature. Accordingly, a translucent, in particular transparent, electrically conductive ink can preferably be used to produce the electrically conductive structure.

[0035] According to an advantageous embodiment of the invention, one or more image features can be incorporated into the printed image by means of several electrically conductive structures that are galvanically isolated. In this way, more complex structures can be made readable, e.g., by sequentially activating them using an input device.

[0036] In further embodiments of the invention, a control mark can be provided with respect to which the intended position of the at least one image feature is determined. The control mark can be provided on the data carrier, and the intended position of the at least one image-specific feature can be determined with respect to the control mark. The control mark can thus serve to define an internal coordinate system of the data carrier. In particular, during the verification of the authenticity of the data carrier on a capacitive screen, the position of the at least one image feature determined during manufacturing on the data carrier can be compared with the actual position. The control mark can be provided on the data carrier, for example, by printing a control mark with visible or invisible ink.

[0037] It is advantageous and preferred to apply the control marking in the same process step as the image itself in order to keep positional tolerances as low as possible.

[0038] The control mark can be defined by a marking, in particular a printed mark, symbol, cross, star, letter, number, or other position applied to the image or to another location on the data carrier, but also by a corner point or center of gravity of a design or sovereign element such as the federal eagle, the country code "DE," or the like. The control mark can also be defined by the printed image itself or by a position on the data carrier itself, for example, a corner or edge position, or the position of a rounded edge. The control mark can advantageously serve to determine the absolute position of the respective image features on the data carrier.

[0039] In principle, the position of the control marker is freely selectable. However, once it is determined, its position can serve as a permanent reference point for determining the position of the image features and be used as the basis for every verification.

[0040] The control marker can define the origin of a data carrier-internal coordinate system, by means of which the positions of the individual image features are defined in the data carrier-internal coordinate system.

[0041] The zero point of the map's internal coordinate system can, for example, be the center of gravity of a sovereign symbol such as the federal eagle, which can be printed on different layers of the data carrier to be produced (UV, VIS, IR, hologram).

[0042] The control marker can be located in the same layer as the image on a data carrier consisting of multiple substrate layers, but it can also be located in a different layer.

[0043] Both in the production of the security or valuable document and in the verification of its authenticity, the determination of at least one image feature can be carried out via the printed image and / or via data from a digital version of the image.

[0044] To calculate an image feature from the printed image, the printed image must first be read, i.e., digitized. In certain embodiments of the invention, a scanning device can be provided for this purpose. The scanning device can be, for example, a document verification device, a camera, or a document scanner. Preferably, the scanning device can be the camera of a smartphone or tablet computer. Digital data from the printed image can be received by means of the scanning device. From the received digital data of the printed image, at least one image-specific feature can now be determined, in particular calculated using an algorithm. This at least one image feature can then be incorporated into the image to be printed or into the printed image in the form of an electrically conductive structure.

[0045] Alternatively, one or more image features can also be determined directly from the data of the digital image. The procedure for determining the image-specific feature from the image can accordingly include: The provision of a camera device for creating digital images, the creation of a digital image of the person using the camera device, and the calculation of at least one image feature from the data of the digital image.

[0046] At least one image feature leads to an individualization of the security or valuable document, preferably to a personalization, because this is derived from the image of the person printed on the document.

[0047] Preferably, the at least one image feature can be a result derived from the person's biometric characteristics, in particular facial features, using an algorithm. The at least one image feature thus represents a result that can only be attributed to the corresponding image and, in particular, only to the person in the image. Therefore, the image feature of each security or valuable document is personalized.

[0048] If the image feature can only be attributed to the person in the image, at least one image feature can serve as a verification feature to check the authenticity of the document and / or, like a fingerprint, as an identification feature for the unambiguous assignment of the security or valuable document to the person depicted.

[0049] Ideally, at least one image feature, or the multitude of image features, has a graphic design that is easily recognizable to a viewer as belonging to the corresponding image, in particular by superimposing them, which can also be done virtually on a screen using suitable software.

[0050] In preferred embodiments, at least one image feature is oriented towards image elements of the printed image. The image feature can be complementary and / or parallel to image elements of the printed image, at least in certain sections. The at least one image feature can be determined by an algorithm that generates the image feature with a corresponding orientation relative to image elements.

[0051] The algorithm for determining the image feature can, in alternative embodiments, include a cryptographic method. It can employ a symmetric encryption method with only one key or an asymmetric encryption method with two different keys. The at least one image feature can be generated in encrypted form in this way, and the corresponding key is required for subsequent verification of the document's authenticity to read the image feature and check its authenticity. This further complicates the imitation or forgery of an image feature.

[0052] The algorithm for calculating at least one image feature, in particular image contours, from the printed image or the digital image data can preferably include a Canny-edge detection algorithm. Canny-edge (or Canny) detection is a robust algorithm widely used in digital image processing for edge detection. It consists of various convolution operations and produces an image that ideally contains only the edges of the original image. To verify that the edge mapping generated by edge detection corresponds to the image of the person, the mapping can be (virtually) superimposed on the image, with the relationship remaining recognizable by the parallel alignment of the edges.

[0053] Canny-edge detection can be used, for example, to extract specific, i.e., unique, algorithm-based contours or support contours from a portrait and output them as a separate contour image. Of course, other algorithms can also be used to extract image-specific features from the visible image.

[0054] Image features can also be calculated using landmark detection. This involves calculating, for example, the positions of individual, specific points of a face, particularly in relation to the data carrier's internal coordinate system.

[0055] Properties of at least one image feature and / or the positions of the respective image feature(s) defined by the control marker are preferably stored as data code on the data carrier. Compared to the storage requirement of a complete image, the storage requirement for storing properties of at least one or a multitude of image features can be significantly lower, while the stored, personalized information still allows for a unique assignment to the image of the person.

[0056] The data code can be stored, for example, on a chip integrated into the data carrier. Alternatively, the data code can be applied to the data carrier as a graphic code, such as a matrix code, in particular a DataMatrix Code (DMC), a barcode, or a QR code. The properties stored on the data carrier enable a further level of document authenticity verification, in addition to verifying the electrically conductive contours.

[0057] The data code can be embedded in the data carrier, for example in the same substrate layer as the printed image and / or the control mark, or in a different substrate layer. It can be perceptible without technical aids or visually imperceptible.

[0058] Preferably, the data code is printed onto the data carrier or a substrate layer, preferably with an ink that can be read by means of a camera of a standard smartphone or tablet computer, and in particular is visually visible. In this way, verification of the security or valuable document, which includes reading the data code, can be carried out solely via standard smartphones and tablet computers.

[0059] The data code preferably contains a signature of the image-specific values ​​to ensure its integrity.

[0060] Preferably, at least one image feature can be printed as an electrically conductive structure onto the data carrier or a substrate layer, particularly using an inkjet printer. The use of an inkjet printer enables efficient and cost-effective personalization.

[0061] The electrically conductive structure can be arranged outside the image and / or within the image. Preferably, the at least one image feature can be arranged in a substrate layer that is located opposite the visible side of the image with respect to the data carrier. For example, the visible side, on which the image is visible, can be located on the front of the data carrier, while the at least one image feature is located on or nearer the back. In this way, during a test procedure in which the document is placed face up on a capacitive touchscreen, the conductive structure is located closer to the capacitive sensor array of the touchscreen. For electrical contacting the at least one image feature with a sensor on the opposite side of the data carrier, e.g.,On the visible side of the image, at least one additional, in particular printed, electrically conductive connector structure can be provided, which connects the at least one image feature generated as an electrically conductive structure to the surface of the visible side for contact.

[0062] The production of the data carrier with the printed image, the additional image feature in the form of a conductive structure within the printed image, and / or the data code can include the additional encoding of the printed image with at least one image feature determined from the data of the digital image in a detectable form. In this context, encoding of the image means that the at least one image-specific image feature is integrated into the image. This integration can be achieved by printing electrically conductive ink into the image, particularly alongside the image. The electrically conductive ink can form visible image elements. This further simplifies the verification of the image's authenticity.

[0063] Alternatively, the electrically conductive ink, after being read by a capacitive sensor, can be used to display an image combined with the printed image. To verify the correspondence between the printed visible image and the image feature encoded in the image, the image feature can first be detected and then displayed in combination with the printed image.

[0064] Within the scope of the present invention, the "encoding of the printed image" can also include the encoding of a layer located above and / or below the image. If the encoding does not take place in the image itself, but in a region in one or more layers above and / or below, i.e., above or below the image, the image can first be printed, and then the electrically conductive structure can be produced in one or more layers above or below the image. The electrically conductive structure can be arranged either in a layer of the data carrier between the image and the visible side of the data carrier, in the visible side of the data carrier itself above the image, and / or on a side of the image facing away from the visible side of the data carrier.

[0065] In another variant, the image is printed, and independently of this, the encoding with at least one image feature of the image takes place in a carrier film, which is then positioned and fixed above and / or below the image.

[0066] At least one image feature can be visible or invisible in visible light. An invisible code has the advantage that it is not easy for a forger to detect.

[0067] The encoding of the printed image with the image features can preferably take place simultaneously with the printing of the visible image, but also before or after the printing of the visible image.

[0068] In a preferred embodiment, the visible image can be printed in a single printing process along with at least one image feature. The image can be encoded (invisibly) on the same level using image features, particularly in addition to the data code described above, and thus secured. For this purpose, the data carrier can include a printed image, in particular alongside the (graphical) data code, into which the image features calculated from the data of the digital image are printed using an electrically conductive ink.

[0069] In this variant, the image, in addition to the visible image, also contains an invisible contour image formed by an electrically conductive structure. This contour image can be made visible using a capacitive sensor to verify its correspondence with the visible image. The visible image is thus overprinted with its own invisible, electrically conductive contour image. A technical advantage of this variant is that mechanical or chemical removal, which also alters the electrically conductive contour image, prevents any correspondence of the image-specific feature from being preserved, neither with the original image nor with the manipulated image, making forgery easily detectable.

[0070] Because an electrically conductive contour image, visible only by means of a capacitive sensor, is provided, image manipulation by foil covering or overprinting becomes visible during an authenticity check, since the unique contour calculated from the data of the digital image only matches the printed image.

[0071] The electrically conductive structure can preferably be incorporated before, after, or during the printing of the image. Preferably, the electrically conductive structure is printed together with the colored inks to create the image using electrically conductive ink.

[0072] Preferably, the printing of at least one image feature, i.e., the electrically conductive structure with electrically conductive ink, can be carried out together with the printing of the visible image using the colored inks. In a preferred embodiment, the printer provides, in addition to the color channels for the process colors (CMYK), a further channel for the electrically conductive ink, so that all inks can be printed simultaneously. The result is an image that, in daylight or when illuminated with white visible light, is a "normal" image of the document holder, but when activated on a capacitive sensor, e.g., on a capacitive touchscreen, can be read by means of a suitable input device containing the image feature, whereby the integrated image feature is "translated" from the electrically conductive structure by means of appropriate software.

[0073] In addition, the contour or landmark image can first be printed with the electrically conductive ink and only then can the visible image be printed into the contour or landmark image, or the visible image can first be created and then the contour or landmark image can be printed into the visible image.

[0074] In another variant, the contour or landmark image is printed with electrically conductive ink onto a first substrate, for example, polycarbonate-based or PVC-based, and the visible image is printed with colored inks onto a second substrate, preferably also polycarbonate-based or PVC-based. The substrates are then positioned relative to each other and joined together, in particular laminated under increased temperature and pressure, as described in DE 10 2007 052 ​​947 A1.

[0075] For printing on data carriers based on polycarbonate polymer layers, the inks known from DE 10 2007 052 ​​947 A1 are preferably used. Such inks contain up to 20 wt.% of a binder with a polycarbonate based on a geminal disubstituted dihydroxydiphenylcycloalkane, at least 30 wt.% of an organic solvent, up to 10 wt.% based on the dry mass of a colorant or colorant mixture, and optionally functional materials, additives, and / or auxiliary substances. Preferred solvents are hydrocarbons and / or ketones and / or organic esters.

[0076] These inks can be printed onto polycarbonate polymer layers using inkjet printers, with the polycarbonate polymer layers then being laminated to form a composite.

[0077] An electrically conductive ink can be used, whereby conductive additives are added instead of or in addition to the aforementioned colorants or colorant mixtures. Printing with conductive additives creates a conductive structure on a polymer layer, which can then be laminated to form a composite.

[0078] By specifically selecting, combining, and, if necessary, adjusting the concentration ratios of one or more conductive additives, the conductivity of the conductive structure can be adjusted to enable detection by a capacitive sensor. The adjusted conductivity can then serve as an additional safety feature.

[0079] By using different conductive inks in the production of one or more image features, different sections of an image feature, or different image features of a security or valuable document, can have varying conductivities. Thus, such a data carrier contains an image and several codes, each based on the image features but encoded in different ways. These different codes, based on the same features, can complement each other in such a way that if one code proves difficult to decode—for example, because the necessary specialized document verification equipment is unavailable—the authenticity of the image can still be verified using the other code.

[0080] A key advantage of this variant of the security and value document according to the invention, with complementary coding, is that the image itself is invisibly encoded and thus secured via characteristic image-specific elements, and that a (different) image-specific encoding of the same image is also stored in a separate data code, for example, a graphic data code such as a matrix code. This allows the image to be verified, for example, using a smartphone with a special barcode reader app and built-in (flash) lighting.

[0081] The data carrier comprises one or more layers of the following polymers or their derivatives, namely polycarbonate, bisphenol-A polycarbonate, carboxy-modified PC, polyesters such as polyethylene terephthalate (PET), its derivatives such as glycol-modified PET (PETG), carboxy-modified PET, polyethylene naphthalate (PEN), vinyl polymers such as polyvinyl chloride (PVC), polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), polyvinyl alcohol (PVA), polystyrene (PS), polyvinylphenol (PVP), polypropylene (PP), polyethylene (PE), polyacrylonitrile butadiene styrene, polyamides, polyurethanes, polyureas, polyimides, or thermoplastic elastomers (TPE), in particular thermoplastic polyurethane (TPU), acrylonitrile butadiene styrene copolymer (ABS), and / or paper and / or cardboard and / or glass and / or metal and / or ceramic. The product may also be made from several of these materials. It preferably consists of PC, PET and / or PVC.The polymers can be either filled or unfilled. In the latter case, they are preferably transparent or translucent. If the polymers are filled, they are opaque.

[0082] The foregoing information refers both to films to be bonded together and to liquid formulations applied to a precursor, such as a protective or topcoat. Preferably, the document is produced from 3 to 12, more preferably 4 to 10, substrate layers (films), preferably using a lamination process in which the substrate layers are fused together under pressure and heat. The individual films can be made of the same material or of different materials. Overlay layers formed in this way protect an underlying security feature and / or provide the document with the required abrasion resistance.

[0083] The invention also relates to a method for verifying the authenticity of a printed image on a data carrier of a security and value document, comprising a printed image, a control mark and a data code based on the image features of the printed image and the position of the control mark, wherein the printed image is read, the position of the control mark is determined, the at least one image feature and its position are calculated and compared with the values ​​stored in the data code.

[0084] If the data code is signed, the signature of the data code can also be verified.

[0085] If the values ​​stored in the data code match the image features calculated from the captured image during the check, taking into account the position of the control mark, then the image is considered unmanipulated.

[0086] The invention also relates to a method for verifying the authenticity of a printed image on a security or valuable document, in particular on a data carrier of the security or valuable document. First, a security or valuable document is provided with a data carrier containing a printed image and at least one image-specific feature incorporated into the data carrier as at least one conductive structure. Also provided is a computer with a capacitive sensor, in particular a touchscreen and / or a camera. Subsequently, at least one image-specific feature is at least partially read out using the capacitive sensor and compared with the expected properties of the at least one image feature.

[0087] The expected properties of at least one image feature will be determined using one or more of the following procedural steps: a) The printed image is read using an image sensor, and the expected properties of the at least one image feature embedded in the data carrier are determined from the read digital image. Advantageously, this method does not require any digitally stored data for authentication. b) A digital representation of the printed image stored in a data storage device of the security or valuable document is read, and the expected properties of the at least one image feature embedded in the data carrier are determined from the digital representation of the printed image. Accessing the digital representation of the image avoids deviations that may occur when reading the image. c) The expected properties of the at least one image feature stored in a data storage device of the security or valuable document are read.The stored expected properties can have a significantly smaller storage requirement than a stored image. d) The properties are read from a data code printed on the data carrier, based on properties of at least one image feature of the printed image. By using a printed data code, a standard camera on an end device, e.g., a smartphone, is sufficient to read the data.

[0088] By combining several of the above steps, the quality and security of authentication can be improved. For example, by determining the properties using an optically scanned image, authentication can still be performed even with a damaged memory chip.

[0089] According to a further embodiment of the method, the computer can determine the position, in particular the position of the centroid, the orientation and / or the size of the at least one conductive structure in the image by means of the capacitive touchscreen when a data carrier is placed on the touchscreen.

[0090] If the properties of the read image feature match expected properties, the image is recognized as genuine. Authenticity detection and / or the output of information regarding the result of the authentication check can be automated using software. If at least one image feature calculated from the captured image based on the position of the control marker and / or the image feature read from the image based on the position of the control marker matches the data code, the information output can confirm the authenticity of the image.

[0091] If no match is found, the printed visible image is a forgery because the image features calculated or read from it do not match the data code in the coordinate system defined by the control mark, for example because the original image was overprinted.

[0092] To reliably verify the authenticity of the image, the calculation should be performed using the same algorithm as the original calculation of the image features from the data of the digital image.

[0093] The authenticity of the data carrier can be verified using a document verification device, but preferably using a computer with a capacitive touchscreen such as a smartphone or tablet computer. Preferably, software can be provided for evaluating the at least one image feature or the electrically conductive structure representing the image feature, as well as for calculating the image features from the printed image.

[0094] In the present application, a "capacitive touchscreen" is understood to be a display device that contains a capacitive sensor arrangement for spatially resolving touches made on it with an input means, such as a finger or a stylus.

[0095] Preferably, the authenticity of the visible image is verified automatically by checking, after the image has been read, whether the at least one expected image feature matches the at least one actual image feature using software running on the computer. This can be done, for example, by virtually overlaying the at least one image feature with the read image.

[0096] A testing arrangement according to the invention for verifying a security or valuable document comprises a computer with a capacitive touchscreen, in particular a smartphone or tablet computer with a capacitive touchscreen, and software for determining at least one image feature. Preferably, only a computer with a capacitive touchscreen and a camera, in particular a smartphone, is required. The visible image can be read out by means of the camera, in particular by taking a photograph. The at least one image feature can then or beforehand be read out by means of the capacitive touchscreen. With software specifically provided for testing the security document, e.g., a testing application, the verification can thus be carried out at least largely automatically.

[0097] In the preferred variant, which uses an electrically conductive structure printed into the image with electrically conductive ink, a digital scan of the printed color image of the valuable or security document can be performed during verification. This allows the at least one image feature expected for the printed image to be calculated from the digital data of the printed image. This at least one expected image feature is then compared with the image feature of the printed image captured by the capacitive touchscreen. If the image feature(s) match, the image of the person is recognized as authentic. An advantage of this method is the possibility of performing all verification steps with a standard device equipped with a capacitive touchscreen, such as a smartphone or tablet computer.

[0098] According to one variant of a method for verifying the security or valuable document, the user touches the data carrier once or several times with a finger or input device and / or moves the finger or input device substantially along the data carrier, generating and receiving a signal receivable by the capacitive sensor of the touchscreen, and using the signal to determine properties of the at least one conductive structure, such as the shape and / or position of the conductive structure.

[0099] To capture the image feature using the capacitive touchscreen, the security or valuable document is first positioned on the capacitive touchscreen of the device used for inspection, such as a smartphone or tablet computer. Moving a finger or stylus along the printed conductive structure of the security document, while the conductive structure is in contact with the touchscreen, generates a changing capacitive signal on the touchscreen. The conductive structure is preferably located in the area of ​​the (photo) image of the person associated with the security or valuable document, with the image area serving as a guide for the inspector and being traversed with the finger or input device.

[0100] Depending on the position of the conductive structure within the security or valuable document, the capacitive signal varies. In this context, the term "capacitive signal" refers to a signal detected by the capacitive touchscreen. The capacitive signal varies as soon as conductive properties vary along at least one direction parallel to the document's surface.

[0101] Using the previously retrieved or determined data of the image feature, which describes the capacitive signal as a function of position, the existing conductive structure can be read via the touchscreen and the resulting image feature can then be compared with the expected image feature.

[0102] During the movement of a finger along the document while the document is on the touchscreen, a data record can be recorded according to preferred embodiments. This data record depends on the varying dielectric and / or conductive properties of the printed conductive structure of the document, making it possible to verify the document and, in particular, the authenticity of the printed visible image.

[0103] In one embodiment, a finger is used to move along the security document on the touchscreen to generate a capacitive signal. This allows the data set to be generated without any additional tools. In another embodiment of the invention, a stylus is used to move across the security document on the touchscreen to generate a capacitive signal. This has the potential advantage of higher accuracy and signal resolution compared to the previously mentioned embodiment.

[0104] In this context, a "pen" is understood to be a tool whose tip can be detected by the touchscreen, i.e., a tool that generates a signal there that can be detected by means of the capacitive touchscreen.

[0105] In order to compare the image features calculated from the captured printed image, and thus at least one image feature expected in the image, with the image features originally calculated and invisibly printed into the colored image using electrically conductive ink, the digital capture of the printed image in the security document should be carried out under the same conditions as the creation of the original digital image, i.e. under white light, preferably with a camera of the device used, i.e., with the camera of a smartphone or tablet computer.

[0106] The method according to the invention can also be applied to other images on security or valuable documents that depict biometric features of the person, for example the person's fingerprint.

[0107] A security document can be designed in the form of a book-like document, such as a passport, and may include a laminated data carrier, a book cover, and a book block in which the data carrier is enclosed.

[0108] A security feature according to the invention for a security or valuable document comprises a data carrier provided with a printed image. The data carrier has an image feature that is incorporated into the printed image as an electrically conductive structure. Furthermore, a control mark is provided for determining the intended position of the at least one image feature in relation to the control mark.

[0109] The invention also relates to a security or valuable document with a data carrier which is provided with a printed image of a person, as well as an image-specific image feature which is incorporated into the data carrier, in particular into the printed image, as an electrically conductive structure.

[0110] Inventory embodiments of the security or valuable document can be designed differently according to the features described above for the method. Preferably, the security or valuable document can be produced using the inventive method.

[0111] According to one embodiment of the security or valuable document, it can be biometrically personalized by means of an electrically conductive structure. This facilitates the evaluation of biometric features during authentication.

[0112] The image feature can be incorporated into the image, in particular integrated into the image. The electrically conductive structure of the security or valuable document can run parallel or complementary to image elements of the printed image, at least in sections. This facilitates the identification of the association of at least one image feature with a specific image. In particular, a visual authentication check can be performed by superimposing the two elements.

[0113] Preferably, the electrically conductive structure is designed and / or arranged in a way that is essentially invisible to an observer. For example, the electrically conductive structure can be the same color as the background or arranged in a concealed substrate layer of the data carrier. This makes counterfeiting after visual detection of the electrically conductive structure more difficult.

[0114] According to a further embodiment of the invention, the security or valuable document can have a control mark, wherein a data code, in particular a graphic code, is stored on the data carrier, which is based on the image features of the image and the position of the control mark. A graphic code offers the advantage of being readable by means of a camera without having to access a memory chip.

[0115] Further advantages and details of the invention are explained in more detail by way of example with reference to the embodiments shown in the schematic figures. These show: Fig. 1 a schematic representation of a security document according to the invention; Fig. 2 a schematic representation of image features of a security document with control marking; Fig. 3 a schematic representation of a method according to the invention for producing a security document; Fig. 4 an arrangement according to the invention for testing a security document; Fig. 5 a schematic representation of a method according to the invention for verifying the authenticity of a security document.

[0116] Exemplary embodiments of the invention are described below with reference to the figures, where identical reference numerals refer to identical elements. It is understood that other embodiments can be created and modifications made without departing from the concept of the present invention. The following detailed description is therefore not to be understood in a limiting sense. Furthermore, it is understood that the features of the various embodiments described herein can also be combined with one another in other ways, unless otherwise specified.

[0117] Figur 1 Figure 1 schematically shows the visible side 10 of a security document 20 with a data carrier 1 bearing a character 11, which, depending on the application, could be, for example, a logo or an official symbol such as the federal eagle. A printed image 12 – here a biometric passport photo – is arranged on the data carrier 1, as well as a data code 13 designed as a graphic code, here a Data Matrix Code (DMC). The biometric passport photo contains image-specific features that are not visible to the viewer, at least under white light. The data code 13 is based on these image-specific features and the position of the character 11, which serves as a control marker 14. The data code 13 can, for example, contain the positions of the centers of gravity of image features.

[0118] The center of gravity 15 of the control marker 14 defines the position of the zero point of the data carrier's internal coordinate system 16.

[0119] Fig. 2 Figure 1 shows, by way of example and schematically, how image-specific features 17 can be represented with electrically conductive structures 18. The electrically conductive structures 18 are printed with electrically conductive ink. As in Fig. 2 As shown, the positions of the centroids of the image features 17 are determined with respect to the coordinate system 16 internal to the data carrier, defined by the centroid 15 of the character 11. The positions of the centroids of the image features 17 are then stored on the data carrier 1 in the DMC code 13.

[0120] The matrix code 13 can be printed on data carrier 1 in white ink or ink that is not visible in daylight, e.g., with transparent ink that absorbs near-infrared (NIR) light. However, it can also be applied to data carrier 1 with luminescent ink or by other means and / or stored in an electronic chip of data carrier 1.

[0121] In the production of the security document 20, a data carrier 1 with at least one substrate or data carrier layer is provided and printed with the character 11, which serves as a control mark, and the image 12 using colored ink. It is irrelevant whether the character 11 or the image 12, or both together, are printed first. If multiple data carrier layers are provided, the character 11 and image 12 can also be printed on different layers of the data carrier 1.

[0122] The next step is to determine the centroid 15 of character 11, which in this case is the orientation point of the control mark 14 and defines the zero point of the data carrier-internal or substrate-internal coordinate system 16, which serves to calculate the image-specific image features 17 and the DMC code. The DMC code 13 is signed and added to the data carrier 20 in a further personalization step.

[0123] In another variant, the image-specific values ​​12 are first calculated from the data of the digitized image 10, and the data code to be included in the DMC code 13 is calculated based on the position of the control mark 14. Subsequently, image 15, control mark 14, and DMC code 13 are printed, preferably simultaneously, onto the data carrier 20.

[0124] Fig. 3 shows the procedural steps of a possible process for producing the security document of the Fig. 1 with image features that are not visible but can be represented by a capacitive sensor. First, a digital image of the person is provided, 31. This can be received, for example, by a digital camera device. One or more image features are calculated from the digital image using an algorithm, 32. One or more image features can be determined from the digital data of the image. In particular, an image feature can be an image-specific contour. Contours can preferably be calculated from the data of the digital image using canny-edge detection. Here, specific contours or support structures are calculated from the portrait and output as a separate contour image ("canny contour").

[0125] Based on the data from the digital image, a raster graphic (bitmap) is created in a raster imaging process (RIP) for color printing of the image. One or more image features can be printed with transparent, conductive ink and thus not included in the creation of the raster graphic. To avoid interfering with the colors to be printed, one or more image features can be printed before the colors or on a separate substrate layer.

[0126] Alternatively, as in the execution of the Fig. 3 Provided that one or more image features can be printed with visible, colored inks - in this case, the one or the multitude of image features are integrated as a separate color channel into the creation of the raster graphic, 33. Subsequently, the at least one or the multitude of image features are printed in a first color channel, 34, the process colors each in a further color channel, cyan, magenta, yellow and core (CMYK) 35, 36, 37, 38.

[0127] The result is a printed image that, in the visible spectral range, is a colored representation of the document owner in the CMYK printing inks. This image also encodes the image features (contours) that can be read using a capacitive touchscreen.

[0128] Fig. 4 Figure 40 shows a test setup for verifying the authenticity of a printed image of a security document 20. The test setup 40 essentially consists of a computer 41 with a capacitive touchscreen 42, in this embodiment designed as a smartphone, with the security document 20 placed on the touchscreen 42. The verification can be carried out at least largely automatically using software specifically provided for testing the security document 20, a test application.

[0129] The position of the security document 20 on the touchscreen 42 can be predefined by the testing application. After placing the security document 20 on the touchscreen, the conductive structure behind the image 12 is read by moving the user's finger or a suitable input device for capacitive screens, such as a stylus, over the image. An example is shown in Fig. 4 A path 43 is shown along which the finger or input device can be moved to generate a signal that can be processed by the capacitive sensor arrangement of the touchscreen 42 and to read the position and / or value of the at least one image feature. The captured signal is modified compared to a document without a conductive structure due to the conductive structure between the input device and the touchscreen. Properties of the conductive structures, and thus of the at least one image feature, are determined from the resulting signal characteristics.

[0130] Fig. 5 This schematically illustrates the process of automated document verification using a computer with a capacitive touchscreen, such as a smartphone or tablet. The following example uses a smartphone.

[0131] First, the printed photograph is read using an image sensor, in particular using a camera integrated into the smartphone, 51. The reading can be done by taking a photograph. Based on the digital data of the read image and an algorithm for generating image features, at least one image feature, i.e., the expected position of the image feature, in particular the center of gravity, with respect to the control mark of the security document and / or other expected properties of the image feature, such as the size and / or shape of the image feature, is determined by computer, in particular calculated, 52a.

[0132] Alternatively or additionally, the data code stored in a security document, e.g., as in Fig. 1 explains the information stored in a DMC code about the expected position of the image feature, in particular the center of gravity, with regard to the control marking of the security document and / or other expected properties of the image feature, such as the size and / or shape of the image feature, which are read out, 52b. The DMC code can be read out using the smartphone's camera.

[0133] Now, at least one image feature is read using the capacitive sensor array of the smartphone's capacitive screen, by scanning the security document as described in... Fig. 4 53. The entire image feature or only a part of the image feature can be read out.

[0134] Finally, at least one image feature determined in step 52a or step 52b is compared with the image feature or part of the image feature read out in step 53, 54. If these match, the image of the security document is verified.

[0135] The features disclosed in the foregoing description, the claims and the drawing can be important for the realization of the various embodiments of the invention, both individually and in any combination. Reference symbol list

[0136] 1 Data carrier 10 Visible side of the security document 11 Character on data carrier 12 Printed image 13 Data code 14 Control mark 15 Center of gravity 16 Coordinate system 17 Image feature 18 Electrically conductive structure 20 Security document 31 Provision of a digital image 32 Calculation of image features 33 Raster imaging process 34 Printing of the image feature 35 Printing of the cyan color channel 36 Printing of the magenta color channel 37 Printing of the yellow color channel 38 Printing of the core color channel 40 Test setup 41 Computer with touchscreen 42 Touchscreen 43 Movement path of the input device 51 Reading the printed image using an image sensor 52a Determining the image feature 52b Reading the DMC code 53 Passing an input device over the image feature 54 Comparison of the read and expected Image feature

Claims

1. Method for producing a security or valuable document (20) with a data carrier (1) bearing a printed image (12) of a person and an image-specific feature (17), comprising the following steps: - providing the data carrier (1), - creating an image of the person, - determining at least one image-specific feature (17) from the image, - printing the image (12), - incorporating the image-specific feature (17) as an electrically conductive structure (18) into the data carrier (1).

2. The method of claim 1, wherein the at least one electrically conductive structure (18) is printed, in particular by means of an ink-jet printer.

3. Method according to one of the above claims, wherein the electrically conductive structure (18) is introduced by means of an ink containing conductive particles and / or a conductive polymer.

4. Method according to one of the above claims, wherein the determination of the image-specific feature (17) from the image comprises: - providing a camera device for creating digital images, - creating a digital image of the person using the camera device and - calculating the at least one image-specific image feature (17) from the data of the digital image.

5. Method according to one of the above claims, wherein properties of the at least one image-specific image feature (17) are stored as data code (13) on the data carrier (1).

6. Method for verifying the authenticity of a printed image (12) of a security or valuable document (20), - wherein a security or valuable document (20) is provided with a data carrier (1) containing a printed image (12) and at least one image-specific feature (17) incorporated into the data carrier as at least one conductive structure, and a computer with a capacitive sensor, in particular a touchscreen (42) and / or a camera, - wherein the at least one image-specific feature (17) is at least partially read out by means of the capacitive sensor and compared with expected properties of the at least one image-specific feature (17), - wherein the expected properties of the at least one image-specific feature (17) are determined by one or more of the following method steps: a) the printed image (12) is read out by means of an image sensor and expected properties of the at least one,a) The image-specific image feature (17) incorporated into the data carrier (1) is determined from the read-in digital image; b) A digital representation of the printed image (12) stored in a data storage device of the security or valuable document (20) is read out, and expected properties of the at least one image-specific image feature (17) incorporated into the data carrier (1) are determined from the digital representation of the printed image (12); c) Expected properties of the at least one image-specific image feature (17) stored in a data storage device of the security or valuable document (20) are read out; d) The properties are read out from a data code (13) printed on the data carrier (1) based on properties of the at least one image-specific image feature (17) of the printed image.

7. Method according to claim 6, wherein the computer (41) determines the position, orientation and / or size of the at least one conductive structure (18) in the image by means of the capacitive touchscreen (42) when a data carrier (1) is placed on the touchscreen (42).

8. Method according to claim 6 or 7, wherein by one or more touches of the data carrier (1) by the user with a finger or an input aid and / or by a movement of the finger or the input aid substantially along the data carrier, a signal receivable by the capacitive sensor of the touchscreen (42) is generated and received, wherein properties of the at least one conductive structure (18), such as the shape and / or position of the conductive structure (18), are determined by means of the signal.

9. Method according to one of claims 6 to 8, wherein the evaluation is carried out using software to determine the at least one image-specific image feature (17).

10. Test arrangement (40) for a method according to one of claims 6 to 9, comprising a computer with a capacitive touchscreen, in particular a smartphone or a tablet computer with a capacitive touchscreen (42), and software for determining the at least one image-specific image feature (17).

11. Security or valuable document (20), comprising a data carrier (1) which is provided with a printed image (12) of a person, and an image-specific image feature (17) which is incorporated into the data carrier (1), in particular into the printed image (12), as an electrically conductive structure (18).

12. Security or value document (20) according to claim 11, wherein the security or value document (20) is biometrically personalized by means of the electrically conductive structure (18).

13. Security or valuable document (20) according to claim 11 or 12, wherein the electrically conductive structure (18) extends at least sectionally parallel or complementary to image elements of the printed image (12).

14. Security or value document (20) according to one of claims 11 to 13, wherein the electrically conductive structure (18) is designed and / or arranged in a manner that is essentially not visible to an observer.

15. Security or value document (20) according to one of claims 11 to 14, wherein the data carrier (1) has a control mark (14) and a data code (13), in particular a graphic code (13), is stored on the data carrier (1) which is based on the image-specific image features (17) of the image (12) and the position of the control mark (14).

Images