Device and method for optically detecting a valuable or security product

Abstract

The invention relates to a device (200) for the optical detection of a valuable or security product (100) with a first security feature (102) that is reconstructed under a first irradiation angle, and with a second security feature (104) that is reconstructed under a second irradiation angle which differs from the first irradiation angle, comprising: - an at least partially transparent support plate (202), - an optical detection device (204), - a partially transparent mirror (206) comprising a front (208) facing the support plate (202) and a rear (210) facing away from the support plate (202), - a first illumination device (212) configured to emit light directly onto the support plate (202) under the first irradiation angle, and - a second illumination device (214) configured to emit light onto the rear (210) of the mirror (206) under the second irradiation angle.wherein it is transmitted through the mirror (206) to the front (208) and thus allowed to pass through to the support plate (202). The invention also relates to a method for the optical detection of a valuable or security product (100).

Description

[0001] The invention relates to a device for optically detecting a valuable or security product having a first security feature that is reconstructed at a first irradiation angle and a second security feature that is reconstructed at a second irradiation angle that deviates from the first irradiation angle. The invention also relates to a method for optically detecting such a valuable or security product.

[0002] Value or security products can be, for example, an identity card, another personal document, a check card, a non-personalised authorization card such as a ticket or a means of payment, or a value or security element intended for product security.

[0003] From the prior art, it is known, for example, to integrate holograms as security features into valuable or security products. Security features or security elements are entities that have at least one characteristic that makes unauthorized duplication, imitation, and / or falsification of an object in which the security element is integrated more difficult. Holograms are used as security features in passports or identity cards, for example. However, they are also used in banknotes, driver's licenses, visas, other security tokens, labels or tickets, credit cards, bank cards, telephone cards, and similar items. Volume holograms represent a special group of holograms. In a volume hologram, a diffractive structure of the hologram is stored in the volume of the holographic recording material.Holographic exposure films, usually supplied on rolls, are typically used as recording materials for volume holograms in valuable and / or security documents. These exposure films are suitable for storing interference structures whose characteristic dimensions are in the range of the wavelength of the light used to record or reconstruct the hologram.

[0004] In a contact copying process, the holographic exposure film is placed in front of a master in which diffractive structures are formed that are to be "transferred" into the holographic exposure film. The diffractive structures of the master are thus copied into the holographic film in this process. For this purpose, coherent light is irradiated onto the master through the holographic film, which is placed in close proximity to the master or in contact with the master. The diffractive structures in the master diffract the light in such a way that the diffracted light is reflected back into the holographic film. There, it interferes with the coherent light used to illuminate the master. An interference structure is thus formed in the holographic film, which is determined by the light diffracted by the master.If the holographic film is developed and reconstructed, the reconstruction resembles the one observed when the master is illuminated. A hologram, also known as a Denisyuk hologram, is stored in the holographic film. It is understood that the incident light must have a suitable wavelength (or wavelengths) and a suitable direction (or directions) of incidence so that diffraction at the diffraction structure occurs in the desired manner.

[0005] For valuable or security products, for example, the use of holographic features formed from volume holograms is suitable, as they are particularly suitable for verification when viewed perpendicularly, for example, to the exposed and developed holographic film. The reconstruction light is preferably irradiated at an acute angle, for example, at 45 degrees to the vertical. The angle between the direction of incidence of the reconstruction light and the direction of reflection of the light diffracted by the generated volume hologram, which reconstructs the hologram's information, is essentially determined during master production.

[0006] DE 10 2007 052 ​​952 A1 describes a security document comprising two adjacent volume reflection holograms, a first volume reflection hologram consisting of a more strongly scattering layer and a second volume reflection hologram consisting of a less scattering layer. For both layers, the intensity of the reconstruction increases the closer one approaches the angle of exposure. This security document has proven itself in practice and offers adequate protection against product counterfeiting.

[0007] US Pat. No. 6,998,623 B2 describes a device for optically detecting fluorescent parts of a valuable or security document. Only a single light source is provided to illuminate a banknote or security document so that the optical detection device can detect light rays emitted in the ultraviolet range.

[0008] US 2008 / 0 265 036 A1 describes a device for optically detecting a valuable or security product that uses two different light sources. All light rays must first pass through a mirror before the optical detection device detects them.

[0009] EP 0 722 597 B1 describes a device for reading valuable or security documents. The device comprises an optical detection device positioned behind a partially transparent mirror. Additionally, a first illumination device is provided, which illuminates the receptacle for the security document via a reflection on the mirror. Additionally, a second illumination device is provided, which directly illuminates the security document. The rays emanating from the security document are transmitted through the partially transparent mirror and then detected by the optical detection device.

[0010] It is the object of the present invention to provide a device and a method which allow a partially or fully automated evaluation of a valuable or security product, wherein the different optically variable security features are machine-readable.

[0011] This object is achieved by a device having the features of claim 1 and by a method having the features of claim 12. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims.

[0012] The device according to the invention comprises an at least partially transparent support plate onto which the valuable or security product can be placed. Furthermore, an optical detection device is provided, the optics of which are directed toward a partially transparent mirror having a front side facing the support plate and a rear side facing away from the support plate. The mirror is positioned in the beam path of the optical detection device in order to deflect light incident on it from the support plate at its front side toward the optical detection device. Furthermore, a first illumination device is provided, which is configured to emit light at the first irradiation angle directly onto the support plate.In addition, a second illumination device is provided which is configured to emit light at the second irradiation angle onto the back of the mirror, wherein it is transmitted through the mirror to the front and thus passed through to the support plate.

[0013] This design offers the advantage that all security features, especially the holographic security features of the valuable or security product, can be reliably optically captured. The aperture angle of the lens of the optical capture device, especially a camera, is designed such that the support plate can be completely captured. This enables full-surface, high-contrast capture of the security features across the entire surface of the valuable or security product, particularly the capture of the Identigram (a registered trademark of the applicant).

[0014] Holographic security features are particularly well visible or reconstructed when irradiated at an angle of incidence that corresponds to or nearly corresponds to the angle of incidence used during exposure of the hologram. In other words, the irradiation angle should correspond to or nearly correspond to the reconstruction angle of the holographic security feature. The greater the proportion of directed light, the more clearly visible security features formed in this way become. To maximize the proportion of directed light beams, it has proven advantageous for the illumination devices to be formed from a light-emitting diode array with a plurality of light-emitting diodes that have a narrow beam angle of between 5 degrees and 15 degrees.Preferably, the light-emitting diodes have a beam angle of 10 degrees, which has proven to be particularly reliable for reconstructing the holographic security features of the valuable or security product.

[0015] In order to increase the proportion of directed light rays onto the support plate and the valuable or security product located thereon, it is also possible to assign a structured light guide to the lighting devices to generate axially parallel light.

[0016] To further enhance the visibility of security features during optical scanning, the use of one or more contrast-enhancing foils has proven effective. These can be applied, for example, to the support plate. Alternatively, the lens of the optical scanning device can also be equipped with such a contrast-enhancing foil.

[0017] The contrast enhancement film can be designed as an optical filter configured to enhance the contrast via the wavelength of the incident light and / or the angle of incidence of the incident light and / or the polarization of the incident light, since the contrast enhancement film filters out wavelengths of "lesser interest." Depending on the emitted wavelength range, multiple films can also be arranged one above the other to enhance the contrast. In this case, the contrast enhancement film is preferably a laminate of multiple film layers arranged one above the other. The films or the film layers themselves can have different optical characteristics. The contrast enhancement film is applied, for example, in a decal process or a contrast enhancement coating is applied as a liquid.

[0018] Another possibility for sending large-area directed light beams onto the support plate is to integrate an F-Theta lens or an F-Theta objective into the beam path of the lighting devices.

[0019] Preferably, the optical detection device is an image sensor of a camera. The camera can be designed as a CCD camera, a NIR (near-infrared) camera, or a UV (ultraviolet) camera. However, the camera is preferably designed as a VIS camera, which detects light rays from the spectrum visible to the human eye.

[0020] Since the reconstruction of holographic security features depends not only on the reconstruction angle but also on the wavelength of the incident light, it is possible that the two security features reconstruct at different reconstruction wavelengths or reconstruction wavelength ranges. Therefore, in order to be able to read valuable or security products equipped with holographic features that reconstruct at different reconstruction wavelengths, it has proven advantageous if the first illumination device is configured to emit light at one wavelength or wavelength range, and if the second illumination device is configured to emit light at a further wavelength or wavelength range that differs from that of the first illumination device.

[0021] For reading the security features of valuable or security products, it has proven particularly reliable if the first irradiation direction of the first illumination device is a 45-degree grazing light. Accordingly, the second irradiation direction of the second illumination device can alternatively or additionally be a 0-degree coaxial light.

[0022] The advantages, advantageous embodiments and effects described in connection with the device according to the invention apply equally to the method according to the invention.

[0023] The method for optically detecting a valuable or security product with a first security feature that is reconstructed at a first irradiation angle and with a second security feature that is reconstructed at a second irradiation angle that deviates from the first irradiation angle comprises in particular the following steps: Placing the valuable or security product on an at least partially transparent support plate, emitting light through a first illumination device at the first irradiation angle directly onto the support plate, and optically detecting the valuable or security product with an optical detection device based on the light emanating from the support plate and deflected at a front side of a partially transparent mirror, and emitting light through a second illumination device to a rear side of the partially transparent mirror, wherein the light is transmitted through the mirror to the front side and allowed to pass through to the support plate at the second irradiation angle, and optically detecting the valuable or security product with the optical detection device based on the light emanating from the support plate and deflected at the front side of the mirror.

[0024] This process also allows the valuable or security product with its holographic security features to be automatically recorded and read.

[0025] If several images are recorded, it is advantageous if all images of the valuable or security product captured by the optical capture device are combined into a single image, so that all holographic security features are visible and can be checked.

[0026] In this context, it is advantageous if the two illumination devices are switched alternately to reconstruct the security features. In particular, a 45-degree grazing light is emitted, which ideally emerges vertically from the surface of the first illumination device and strikes the support glass. It strikes the support plate at a 45-degree angle.

[0027] The second illumination device emits 0-degree coaxial light, which ideally emerges perpendicular to its surface and strikes the support plate. It passes through the semi-transparent mirror and strikes the support plate perpendicularly, thus at an angle of 0 degrees relative to the surface normal to the support plate.

[0028] In order to reduce the number of images to be evaluated, it has proven advantageous if the exposure time of the optical detection device remains behind the frequency of the mutual switching of the two illumination devices.

[0029] The valuable or security product provided with the multiple security features can be a valuable or security document or a security element, i.e. an element that is, for example, connected to an object to be protected against imitation, forgery, or falsification, such as a sticker, label, or the like. Examples of valuable or security products that may be considered are a passport, identity card, driver's license, other ID card, or access control card, vehicle registration document, vehicle registration certificate, visa, check, other means of payment, in particular a banknote, check, bank, credit, or cash payment card, customer card, health card, chip card, company ID, proof of authorization, membership card, or other ID document.

[0030] The valuable or security product is preferably in ID 1, ID 2, ID 3, or some other format, for example, in booklet form, similar to a passport-like item. The valuable or security product is generally a laminate of multiple document layers that are precisely bonded together under heat and increased pressure. These products should meet standardized requirements, for example, ISO 10373, ISO / IEC 7810, and ISO 14443.

[0031] The product layers preferably consist of a carrier material suitable for lamination. However, the valuable or security product can preferably be formed from a polymer selected from a group comprising polycarbonate (PC), in particular bisphenol A polycarbonate or a polycarbonate formed with a geminal disubstituted bis(hydroxyphenyl)cycloalkane, polyethylene terephthalate (PET), derivatives thereof, such as glycol-modified PET (PETG), polyethylene naphthalate (PEN), polyvinyl chloride (PVC), polyvinyl butyral (PVB), polymethyl methacrylate (PMMA), polyimide (PI), polyvinyl alcohol (PVA), polystyrene (PS), polyvinylphenol (PVP), polypropylene (PP), polyethylene (PE), thermoplastic elastomers (TPE), in particular thermoplastic polyurethane (TPU), acrylonitrile-butadiene-styrene copolymer (ABS) and derivatives thereof, and / or paper and / or cardboard and / or glass and / or metal and / or ceramic.Furthermore, the product can also be made from several of these materials. It preferably consists of PC, PVC, and PET. 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. The above information refers both to films to be bonded together and to liquid formulations applied to a precursor, such as a protective or topcoat. The product is preferably made from three to twelve, preferably four to ten, films. The films can also carry printing layers. A laminate formed in this way can then be coated on one or both sides with the protective or topcoat or with a film. The film can, in particular, be a volume hologram, a film with a surface hologram (for example, a cinematic element), or a scratch-resistant film.Overlay layers formed in this way protect a security feature arranged underneath and / or provide the document with the necessary abrasion resistance.

[0032] The present invention is explained in more detail below with reference to figures, whereby the illustrated examples are merely exemplary and do not represent a limitation with regard to the scope of the described invention. They show in detail: Figure 1 shows a schematic side view of a device for optically detecting a valuable or security product which is placed on the support plate, Figure 2 shows a top view of a valuable or security product in the form of an identity card, in which the first security features are reconstructed due to the illumination at the first irradiation angle, and Figure 3 shows one of the Figure 2corresponding representation of the valuable or security product, in which the second security features are reconstructed because they are irradiated under the second irradiation angle.

[0033] In the Figures 2 and 3 A valuable or security product 100 is shown, which is exemplified in the form of an identity card, which has been assembled, for example, as a laminate of several internal polymer layers. For example, the polymer layers can be made of PC and / or PET. The individual layers can be unfilled or filled with fillers. In the latter case, they are opaque; otherwise, they are transparent. The layers can preferably be bonded together in such a way that they form a monolithic block that is practically impossible to split.

[0034] It can be seen that the identity card is equipped with security features 102, 104 in the form of an Identigram (a registered trademark of the applicant). These form individual volume reflection holograms, whereby the arrangement, size, and shape are chosen purely as examples, so that other arrangements, sizes, or dimensions of the security features 102, 104 are also possible.

[0035] Based on the Figures 2 and 3 It can be seen that the valuable or security product 100 has a top side opposite a bottom side. The top side contains the face or portrait image of the cardholder, as well as several data fields containing personal or document-related content.

[0036] In the view of Figure 2The first security features 102 of the identity card are visible because this valuable or security product 100 is irradiated from a first irradiation angle such that the first security features 102 are reconstructed. In this case, the valuable or security product 100 is irradiated with 45-degree grazing light from a first illumination device 212.

[0037] In Figure 3 Second security features 104 are visible because the valuable and security product 100 is illuminated at a second irradiation angle such that the second security features 104 are reconstructed. The irradiation is carried out using a second illumination device 214, which emits a 0-degree coaxial light onto the top of the valuable or security product 100.

[0038] To protect the valuable or security product 100, in particular the identity card according to the Figures 2 and 3 In order to be able to read the data mechanically, a device 200 is used which is Figure 1is shown.

[0039] Figure 1shows a device 200 for optically detecting a valuable or security product 100 with a first security feature 102 that is reconstructed at a first irradiation angle, and with a second security feature 104 that is reconstructed at a second irradiation angle that deviates from the first irradiation angle. The device 200 comprises an at least partially transparent support plate 200 onto which the valuable or security product 100 can be placed. The support plate 202 is preferably made of transparent glass so that it does not appear only partially transparent. An optical detection device 204, in this case in the form of a camera, is also present, the lens of which uses a relatively small camera aperture angle, thereby creating the longest possible optical path. The length of the optical path is designed such that the support plate 202 is completely detected at the aperture angle of the camera.This is advantageous because the security features 102, 104, which are stimulated by the illumination, are only visible within a limited angular range perpendicular to the surface. If this angle is exceeded, the contrast of the security features 102, 104 decreases, and they are no longer as clearly visible in the edge areas.

[0040] The valuable or security product 100 is detected by the optical detection device 204 using a partially transparent mirror 206. This partially transparent mirror 206 comprises a front side 208 facing the support plate 202 and a rear side 210 facing away from the support plate 202. It is thus positioned in the beam path of the optical detection device 204 in order to deflect light incident on it from the support plate 202 at its front side 208 toward the optical detection device 204.

[0041] To ensure that the two security features 102, 104 are reliably reconstructed, two illumination devices 212, 214 are provided, which emit the most highly directed light possible. Such highly directed light is achieved, for example, by the illumination devices 212, 214 being formed from a light-emitting diode array with a plurality of light-emitting diodes that have a narrow beam angle of between 5 degrees and 15 degrees, in particular a beam angle of 10 degrees. To ensure that the light is as axially parallel as possible, the illumination devices 212, 214 can also be provided with a structured light guide. The illumination devices 212, 214 or the support plate 202 or the lens of the optical detection device 204 can be coated with at least one contrast-enhancing film to make the holographic security features 102, 104 more clearly visible.Alignment of the beams of the two illumination devices 212, 214 can also be achieved by using an F-theta lens or an F-theta objective in the beam path of the illumination devices 212, 214. It is possible for the two illumination devices 212, 214 to also emit light from a different wavelength range or at different wavelengths.

[0042] The first illumination device 212 is configured to emit light at the first irradiation angle directly onto the support plate 202, wherein the second illumination device 214 is configured to emit light at the second irradiation angle onto the rear side 210 of the mirror 206, wherein this light is transmitted through the mirror 206 to the front side 208 and thus passed through to the support plate 202.

[0043] In this case, the first illumination device 212 emits a 45-degree grazing light 216, which reliably reconstructs the first security features 102. The light rays thus strike the support plate 202 at an angle of 45 degrees relative to the surface normal of the support plate 202.

[0044] The second illumination device 214 emits 0-degree coaxial light 218, which impinges on the support plate 202 at an angle of 0 degrees with respect to the surface normal of the support plate 202.

[0045] In order to optically detect the valuable or security product 100, the following steps are carried out in particular: Placing the valuable or security product on the transparent support plate 202, emitting light through the first illumination device 212 at the first irradiation angle directly onto the support plate 202, and optically detecting the valuable or security product 100 with the optical detection device 202 based on the light emanating from the support plate 202 and deflected at the front side 208 of the partially transparent mirror 206, and emitting light through the second illumination device 214 to the rear side 210 of the partially transparent mirror 206, wherein the light is transmitted through the mirror 206 to the front side 208 and allowed to pass through to the support plate 202 at the second irradiation angle, and optically detecting the valuable or security product with the optical detection device 204 based on the light emanating from the support plate 202 and deflected at the front side 208 of the mirror 206.

[0046] The images of the valuable or security product 100 captured by the optical capture device 204 can be combined into a single image. Generating individual images is also possible and advantageous for evaluating the holographic security features 102, 104.

[0047] In order to reconstruct all security features 102, 104, the two lighting devices 212, 214 are preferably switched alternately.

[0048] In order to record only a single image in which all security features 102, 104 are visible, it is possible that the exposure time of the optical detection device 204 lags behind the frequency of the mutual switching of the two illumination devices 212, 214.

[0049] The present invention thus offers a solution for the optical inspection of holographic security features 102, 104, in particular the Identigram (a registered trademark of the applicant), in a partially or fully automated manner. The mutual arrangement of the constituents of the present device 100 results in a particularly compact design, effectively utilizing the available installation space in document inspection devices. LIST OF REFERENCE SYMBOLS

[0050] 100Value or security product 102First security feature 104Second security feature 200Device 202Support plate 204Optical detection device 206Semi-transparent mirror 208Front 210Rear 212First illumination device 214Second illumination device 21645-degree grazing light 2180-degree coaxial light

Claims

1. A device (200) for optically detecting a value or security product (100) comprising a first security feature (102) which reconstructs at a first irradiation angle and a second security feature (104) and which reconstructs at a second irradiation angle that differs from the first irradiation angle: - an at least partially transparent support plate (202) on which the value or security product (100) can be placed, - an optical capture device (204), - a partial-reflector mirror (206), which comprises a front (208) facing the support plate (202) and a back (210) facing away from the support plate (202), and which is positioned in the beam path of the optical capture device (204) in order to deflect a light impinging on it from the support plate (202) at its front (208) in the direction of the optical capture device (204), - a first lighting device (212), which is set up to emit light directly to the support plate (202) at the first irradiation angle, and - a second lighting device (214) arranged to emit light at the second irradiation angle onto the back (210) of the mirror (206), whereby it is transmitted through the mirror (206) to the front (208) and thus transmitted to the support plate (202).

2. The device according to claim 1, characterized in that the lighting devices (212, 214) are formed from a light-emitting diode arrangement having a plurality of light-emitting diodes which have a narrow beam angle of between 5 degrees and 15 degrees.

3. The device according to claim 1 or 2, characterized in that a structured light guide is assigned to the lighting devices (212, 214) for generating light parallel to the axis.

4. The device according to one of claims 1 to 3, characterized in that the support plate (202) is covered with at least one contrast enhancement film.

5. The device according to claim 4, characterized in that the contrast enhancement film is designed as an optical filter which is set up to enhance the contrast via the wavelength of the incident light.

6. The device according to claim 4 or 5, characterized in that the contrast enhancement film is designed as an optical filter which is set up to enhance the contrast via the angle of incidence of the incident light.

7. The device according to one of claims 4 to 6, characterized in that the contrast enhancement film is designed as an optical filter which is set up to enhance the contrast via the polarization of the incident light.

8. The device according to one of the claims 4 to 7, characterized in that the contrast enhancement film is a laminate of several film layers on top of each other.

9. The device according to claim 8, characterized in that the film layers have different optical characteristics.

10. The device according to any one of claims 1 to 9, characterized in that an F-theta lens or an F-theta objective is included in the beam path of the lighting devices (212, 214).

11. The device according to one of claims 1 to 10, characterized in that the first irradiation direction of the first lighting device (212) is 45-degree sidelight and / or the second irradiation direction of the second lighting device (214) is 0-degree coaxial light.

12. A method of optically detecting a value or security product (100) having a first security feature (102) that reconstructs at a first irradiation angle and a second security feature (104) that reconstructs at a second irradiation angle that differs from the first irradiation angle, comprising the steps of: - placing the value or security product (100) on an at least partially transparent support plate (202), - emitting light by a first lighting device (212) at the first irradiation angle directly to the support plate (202) and optically detecting the value or security product (100) with an optical capture device (204) on the basis of the light emitted by the support plate (202) and deflected at a front (208) of a partial-reflector mirror (206), and - sending light through a second lighting device (214) to a back (210) of the partial-reflector mirror (206) the light being transmitted through the mirror (206) to the front (208) and transmitted to the support plate (202) at the second angle of irradiation, and optical detection of the value or security product (100) with the optical capture device (204) by means of the light emitted by the support plate (202) and deflected at the front (208) of the mirror (206).

13. The method according to claim 12, characterized in that all images of the value or security product (100) captured by the optical capture device (204) are combined into a common image.

14. The method according to claim 12 or 13, characterized in that the two lighting devices (212, 214) are switched alternately in order to reconstruct the security features (102, 104).

15. The method according to claim 14, characterized in that the exposure time of the optical capture device (204) lags behind the frequency of the reciprocal switching of the two lighting devices (212, 214).

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