Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/04—Processes or apparatus for producing holograms
  • G03H1/0476—Holographic printer
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/0005—Adaptation of holography to specific applications
  • G03H1/0011—Adaptation of holography to specific applications for security or authentication
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/04—Processes or apparatus for producing holograms
  • G03H1/20—Copying holograms by holographic, i.e. optical means
  • G03H1/202—Contact copy when the reconstruction beam for the master H1 also serves as reference beam for the copy H2
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2249—Holobject properties
• • G—PHYSICS
  • G07—CHECKING-DEVICES
  • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
  • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
  • G07D7/003—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using security elements
  • G07D7/0032—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency using security elements using holograms
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
  • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
  • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
  • B42D25/30—Identification or security features, e.g. for preventing forgery
  • B42D25/328—Diffraction gratings; Holograms
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/02—Details of features involved during the holographic process; Replication of holograms without interference recording
  • G03H1/0252—Laminate comprising a hologram layer
  • G03H1/0256—Laminate comprising a hologram layer having specific functional layer
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/04—Processes or apparatus for producing holograms
  • G03H1/20—Copying holograms by holographic, i.e. optical means
  • G03H2001/205—Subdivided copy, e.g. scanning transfer
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2202—Reconstruction geometries or arrangements
  • G03H2001/2244—Means for detecting or recording the holobject
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2249—Holobject properties
  • G03H2001/2263—Multicoloured holobject
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
  • G03H1/22—Processes or apparatus for obtaining an optical image from holograms
  • G03H1/2249—Holobject properties
  • G03H2001/2263—Multicoloured holobject
  • G03H2001/2271—RGB holobject
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2210/00—Object characteristics
  • G03H2210/50—Nature of the object
  • G03H2210/54—For individualisation of product
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2222/00—Light sources or light beam properties
  • G03H2222/10—Spectral composition
  • G03H2222/17—White light
  • G03H2222/18—RGB trichrome light
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2222/00—Light sources or light beam properties
  • G03H2222/34—Multiple light sources
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2223/00—Optical components
  • G03H2223/12—Amplitude mask, e.g. diaphragm, Louver filter
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2225/00—Active addressable light modulator
  • G03H2225/30—Modulation
  • G03H2225/31—Amplitude only
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
  • G03H2240/00—Hologram nature or properties
  • G03H2240/50—Parameters or numerical values associated with holography, e.g. peel strength
  • G03H2240/52—Exposure parameters, e.g. time, intensity

Definitions

• the invention relates to holograms as security elements, to security documents which comprise such holograms as security elements, to methods for producing such holograms and security documents and to a device for producing a hologram as security element and to a device for verifying such a hologram or security document.
• Security elements are used to secure security documents, which also include value documents, against counterfeiting or copying.
• One type of security element is represented by holograms.
• Security elements often include individualizing details, such as serial number, passport number, biometric data, pictures (passport photos), etc. These can be provided in plain text or image form or optically coded or machine-readable.
• a holographic master is made with a master hologram. Then, the holographic master is positioned behind a holographic recording material. Coherent light, for example from a laser, is irradiated onto the side of the holographic recording material facing away from the holographic master, typically with a defined wavelength and a defined angle of incidence, in accordance with the holographic pattern to be reconstructed by the holographic master.
• the holographic master can be designed so that it is sensitive to several wavelengths and this bends accordingly. Also, other than the described arrangement can be used to produce holograms. To individualize holograms, this can be coherent
• Light can be modulated by a Spatial Light Modulator. As a result, an individualization pattern is impressed on the hologram.
• DMD Digital Micro Mirror Device
• DMD Digital Micro Mirror Device
• Modern passports and ID cards comprise as a security element a hologram, which is individualized with an individualization pattern representing the passport photo.
• a hologram which is individualized with an individualization pattern representing the passport photo.
• a color impression of the hologram changes for the viewer, since, depending on the viewing angle, the hologram is in each case visible in one of different spectral colors.
• the invention is therefore based on the technical object of providing a production method and an apparatus for producing holograms as well as such holograms and security documents as well as a method for producing such security documents with a hologram as a security feature, in which the hologram is more difficult to produce by counterfeiters than the known holograms is and still allows a reliable verification.
• a further object of the invention is to provide a method and a device for verifying such improved holograms or security documents provided with such holograms. definitions
• a security element is a structural unit comprising at least one security feature.
• a security element can be an independent structural unit which can be connected, for example glued, to a security document, which can also be a value document. But it can also be an integral part of a security document.
• An example of the first is a visa sticking on a security document.
• An example of the latter is a hologram integrated into a bill or passport, for example laminated.
• a security feature is a structure that can only be produced or reproduced with (compared to simple copying) increased effort or not at all unauthorized.
• a pattern typically consists of a multiplicity of juxtaposed pattern units or pixels.
• the pattern units or pixels of a pattern are associated with one another and arranged laterally in a defined manner, typically in one or two spatial dimensions, and overall give a representation, for example a picture, a symbol, a logo, a lettering (letters, numbers, alphanumeric) or a code (eg a barcode).
• An individualization pattern is a pattern that is used for individualization.
• Security and / or value documents may be mentioned by way of example only: identity cards, passports, ID cards, access control cards, visas, tax stamps, tickets, driving licenses, motor vehicle papers, banknotes, checks, postage stamps, credit cards, any chip cards and adhesive labels (for example for product security).
• Such security and / or value documents typically have a substrate, a printing layer and optionally a transparent cover layer.
• a substrate is a support structure to which the print layer is applied with information, images, patterns, and the like. Suitable materials for a substrate are all customary materials based on paper and / or plastic in question.
• a Spatial Light Modulator allows a two-dimensionally spatially resolved illumination or irradiation of a mostly flat object with modulated intensity.
• This can be, for example, a DMD (Digital Micro Mirror Device) chip, an LCD (Liquid Crystal Display) transmission display or LCoS (Liquid Crystal on Silicon) Act on the display. All have in common that a multiplicity of SLM pixels is formed, wherein each SLM pixel is activatable or deactivatable independently of other SLM pixels (intermediate stages are also possible), whereby by appropriate control of the SLM pixels, patterns or images can be projected , Due to the free controllability also different images or patterns can be generated in succession in a row, for example in the form of a passport photo.
• a code or pattern is individualizing if it is unique to a person or an object or a group of persons or objects from a larger total of persons or objects. For example, a code individualizing a group of persons within the total population of a country is the city of residence. An individualizing for a person code, for example, the number of the identity card or passport photo. A code individualizing a group of bills within the total amount of bills is the value. Individualizing for a banknote is the serial number. Examples of non-individualizing codes or patterns are coats of arms, seals, insignia, etc.
• a holographic recording material is a layer of a material that is photosensitive, and in which holograms can be stored by irreversible, but also reversible photochemical and / or photophysical processes by exposure.
• the photopolymers often used in holography may be mentioned.
• color is understood in the context of the invention as a wavelength or a spectral line. Mixed colors have several different wavelengths or spectral lines. The term color therefore also includes UV and IR in addition to the visible range.
• a volume hologram is a hologram in which the structures formed and imaged by interference extend from a surface of the hologram or holographic recording material. These structures can be considered as multiple Bragg planes in the material.
• a volume hologram therefore has a high wavelength selectivity, so it can only be reconstructed with the spectral color with which it was exposed.
• Many holographic materials have a shrink or swelling process during fixation, which shifts the reconstruction wavelength. This effect can also be brought about deliberately, as described in EP 0919961 B1. In this case, the reconstruction is done with a different color than the one that was exposed.
• hologram or region of a hologram has a spectral color to mean that the hologram or region can only be reconstructed with the spectral color that it "has.” In a volume reflection hologram, this means that the hologram is perceived in the corresponding color when viewed when illuminated by a white light source whose light comprises the spectral color harboring or hologram, ie with which the hologram or area was exposed.
• a method for producing such a hologram as a security feature comprises the steps of providing a hologram master, arranging a holographic recording material in front of the hologram master, irradiating the holographic recording material with coherent light so that at least part of the coherent light is reflected and / or diffracted at the hologram master and interfering with the coherent light passing through the holographic recording material to expose the hologram in the holographic recording material, wherein providing the hologram master comprises providing a hologram master that diffracts and / or reflects coherent light of different spectral colors at each position and the coherent one Light is monochromatically generated or monochromatieriscope and the holographic recording material at different locations along at least one excellent direction with monochromatic Lic ht of different spectral colors is exposed according
• a hologram security device used therefor includes a hologram master, a holographic recording material holder and / or guide and a coherent light emitting light source, and imaging optics for guiding the coherent light to coherent light the holographic recording material such that at least a portion of the coherent light is diffracted and / or reflected at the hologram master to interfere with the coherent light radiating through the holographic recording material in the holographic recording material, the hologram master at each position diffracting coherent light of different spectral colors and / or reflected and the light source is adapted to produce light of different spectral colors monochromatically, so that different areas of the holographic recording material with light of different spectr All colors are irradiated and exposed depending on a position along an excellent direction of the hologram according to a predetermined color pattern.
• a hologram is formed that includes contiguous regions along at least one excellent direction that have a different spectral color. Since the individual areas each have exactly one spectral color, an exposure of the individual areas is possible in such a way that in each case an optimum diffraction efficiency results for the corresponding spectral color. This ensures that a colored reflection hologram is formed, which is simply colored under a reflection geometry, for example with a white light source.
• a preferred method for producing an improved security document thus comprises the production of a reflection hologram according to the method just described and a method step of integrating the reflection hologram into the security document.
• a preferred verification of a hologram or security document with such a hologram provides that the hologram is reconstructed with light of different spectral colors and is detected in a spectrally resolved manner and a color pattern is determined which indicates a color sequence and extent of regions along at least one direction of the hologram and this determined color pattern is compared with a predetermined color pattern.
• a corresponding verification device for a hologram and / or a security document with such a hologram comprises a light source, which can generate light of different spectral colors, and a detection unit, which can detect the reconstructed hologram spectrally resolved, and an evaluation unit, which detected from the spectrally resolved reconstructed hologram determines a color pattern indicating a color sequence and extent of regions along at least one excellent direction of the hologram, and a comparison unit for comparing the color pattern with the predetermined color pattern.
• the invention has the advantage that a colored hologram is produced, for the falsification of which coherent light of different spectral colors is required, but on the other hand, detection of the hologram is furthermore simply completely possible. All areas that have different spectral colors, each diffract a corresponding color efficiently, since the individual areas are each designed as volume holograms and have a good wavelength selectivity.
• the hologram is preferably created along the excellent direction from monochromatic sub-holograms of different spectral colors. These partial holograms are preferably strip-shaped and designed as volume reflection holograms. This means that the coherent light is generated as a stripe and images the hologram master strip by strip.
• the different spectral colors can be selected both in the infrared wavelength range, in the UV wavelength range and in the visible wavelength range and / or a combination thereof.
• the different spectral colors lie in the visible spectral range and, at a reconstruction with a white light source comprising light of the wavelength of the different spectral colors, from a human observer under a predetermined illumination angle viewing angle geometry simultaneously different Spectral color areas are perceived as a total color hologram.
• the diffraction efficiencies of the hologram are nearly identical with respect to the different spectral colors.
• the diffraction efficiencies for different spectral colors in the different spectral regions are the same, provided that the hologram master has an identical structure in the sections corresponding to the regions.
• a thickness of the holographic recording material used slight variations may occur depending on the color.
• Maximum diffraction efficiency is dependent on the wavelength at low thicknesses of the recording material as the hologram broadening levels extend through the entire thickness of the holographic recording material. The number of fragments in the recording material in this case depends on the wavelength.
• the diffraction efficiency of the individual colors can be evaluated and compared with default values and / or expected values. This can be done by machine. Fake holograms in which some or all colors have lower diffraction efficiency than real holograms can also be detected by visual inspection by human control personnel, as the individual colors are perceived to be weaker "glowing" than expected Forgery in which the wavelength of the light used in the forgery does not optimally agree with the wavelength intended for reconstruction of the original hologram will have a lower diffraction efficiency for that wavelength than the original hologram, and these diffraction efficiency differences are in the original and counterfeit and for the skilled People also recognizable by comparing the counterfeit with an expected color impression.
• an exposure, in particular an exposure time, of the corresponding area is selected optimally for the corresponding spectral color, so that an optimum desired diffraction efficiency results for this. Since known holographic recording materials usually have a different sensitivity with regard to the different spectral colors, an exposure time for the different spectral colors must each be adapted.
• the hologram master is scanned stepwise during the exposure of the hologram and the hologram is thus composed of partial holograms.
• Particularly preferred is an embodiment of the method in which the holographic recording material and the hologram master on the one hand and the coherent light of a light source on the other hand are moved relative to each other, wherein a relative speed adapted to a spectral sensitivity of the holographic recording material for each currently used for the exposure spectral color of coherent light is adjusted.
• the device according to the invention thus preferably comprises a drive unit which is designed to effect a relative movement of the coherent light on the one hand and the holographic recording material and the hologram master on the other hand.
• a control unit is provided to control the relative movement and / or an intensity of the light depending on a spectral sensitivity of the holographic recording material with respect to the correspondingly used spectral color.
• a control unit is provided to control the relative movement and / or an intensity of the light depending on a spectral sensitivity of the holographic recording material with respect to the correspondingly used spectral color.
• a spectral change is to be made within a time that is small in relation to the exposure times of the holographic recording material for the different spectral colors. Only in this way can it be ensured that individual areas of the Holograms at the transitions between the different areas also each have a high diffraction efficiency for the different spectral colors.
• the coherent light is modulated by a spatial light modulator prior to irradiating the holographic recording material to form an individualization pattern in the hologram.
• the modulation thus takes place before the radiation of the holographic recording material and also before diffraction or reflection at the hologram master.
• Spatial Light modulators are in particular Liquid Crystal on Silicon, DMDs and LCD displays into consideration.
• an exposure of the hologram with the different spectral colors is carried out in a step-and-repeat method (step-and-repeat method).
• a method may use a spatial light modulator adapted to a width of the stripe-shaped coherent light used for exposure.
• a line display comprising one or more pixel rows can be used to advantage. This is in each case controlled in such a way that a partial area of the individualization pattern is shown, which corresponds to the corresponding section of the hologram which is exposed.
• the holographic marking material and the hologram master, on the one hand, and the coherent light, on the other hand, are moved in stepwise synchronism with the changed driving of the spatial light modulator, when formed as a line display, relative to one another.
• a planar Spatial Light Modulator is used, a synchronization of a movement of the coherent light via the Spatial Light Modulator with this is not required, so that a control is easier.
• a relative movement of the coherent light to the holographic recording material and the hologram master can be carried out in a simple manner by means of imaging optics, which at the same time effects a scanning of the planar-shaped spatial light modulator.
• An anti-forgery security of the hologram and of a security document equipped therewith is increased, in particular, by the fact that an individualization feature is coded by means of the regions of the hologram which have a different spectral color.
• a color sequence of the different areas and an extension of the different areas along the direction defines a color pattern. This is preferably given individually for each hologram.
• a particularly high security against counterfeiting can be achieved if the given color pattern can be calculated from a primary feature associated with the hologram or, for example, a security document, in particular an individualization feature, with a unique but irreversible computing algorithm.
• a primary feature a passport number, a name, a date of birth, etc., or even a passport photograph or other biometric data or a combination thereof encoded in the security document may be used, for example, in a security document.
• the customization pattern is used as a primary feature.
• a link between the individualization pattern and the color pattern which specifies the sequence and extent of the regions of different spectral color which follow one another along the direction of the hologram, is defined. If the individualization pattern, for example a passport picture, is changed, the associated color pattern with which such a hologram is produced also changes.
• the computational algorithm or private key is not kept secret for counterfeiters, it is not possible to obtain the correct color pattern.
• the calculation algorithm does not have to be one-to-one in such a way that exactly one color pattern is assigned to each individualization pattern. Rather, similar individualization patterns may be associated with the same color pattern. It is also possible that even very different individualization patterns are assigned to the same color pattern. However, if the number of color patterns used is large enough, then a probability of guessing a color pattern assigned to a specific individualization pattern via the calculation algorithm is very small, so that a forgery of an individualized hologram is almost impossible.
• the primary feature is detected, the predetermined color pattern is calculated and compared with the detected color pattern.
• the color pattern or otherwise predefined color pattern derived from the primary feature Security document coded store is advantageous to have the color pattern or otherwise predefined color pattern derived from the primary feature Security document coded store.
• the coded deposited color pattern is stored in encrypted form and / or secured against access by unauthorized persons, for example in a chip integrated in the security document.
• the hologram has an identical angular selectivity with respect to a reconstruction for the different spectral colors. A slight tilting of the hologram with respect to the optimal reconstruction geometry thus affects the regions of different spectral color in the same way.
• the individual regions of the hologram for the different spectral colors each have the same reconstruction geometry.
• the production of such a hologram is particularly possible with a hologram master, which itself represents a holographic image of a ground glass, which scatters light of different spectral colors almost identically at one and the same location.
• the hologram master is produced by holographic imaging of a ground glass which diffuses the light of the different spectral colors at one location, ie images light of different spectral colors under the same geometric conditions.
• the ground glass is preferably first imaged into a transmission gramgram. This is reconstructed so that a reconstruction in a holographic Recording material is formed and exposed there in a reflection hologram, which represents the hologram master.
• the hologram is preferably produced and arranged between two layers, which are then laminated with optionally further layers to form a document body.
• the hologram may be adhered to a document body and optionally covered with a scratch-proofing film or a scratch-proof paint. Methods for this purpose are described for example in the not yet disclosed patent application DE 10 2006 048 464.
• Fig. 1 is a schematic representation of an apparatus for producing a
• Fig. 2 is a schematic representation of a hologram
• Fig. 3 is a schematic representation of a method for producing a
• Security document which comprises a method for producing a hologram
• Fig. 4 is a schematic representation of an apparatus for verification of a
• a device 1 for producing a hologram is shown schematically.
• a holographic recording material 4 is arranged on a guide 3.
• the guide 3 is arranged relative to the hologram master 2 so that the holographic recording material 4 is preferably in full contact with the hologram master 2.
• a transparent protective layer (not shown), preferably of polyethylene terephthalate (PET), may be disposed between the holographic recording material 4 and the hologram master 2 can.
• PET polyethylene terephthalate
• the hologram master 2 is preferably a holographic structure produced by holographic imaging of a ground glass with different spectral colors, and has the property of diffracting light of different spectral colors almost identically, in particular at identical angles, at each position.
• the device 1 further comprises a light source 5 capable of producing coherent light of the different spectral colors.
• the light source 5 may comprise, for example, a plurality of lasers 6 which generate light of the different spectral colors.
• the light source 5 is designed such that it selectively controls, via a merging and selection unit 7, light of a selected spectral color of the different spectral colors.
• the coherent light 8 is preferably provided by the light source 5 as a stripe-shaped light beam. This means that the light beam is extended transversely to the propagation direction along a spatial dimension. This extension preferably corresponds to at least one width or height of the hologram to be produced. In the example shown, the coherent light 8 is stretched perpendicular to the plane of the strip.
• the device 1 further comprises an imaging optics, which is shown here in simplified form as a deflection mirror 9.
• the imaging optics are designed such that the coherent light 8 is passed through a spatial light modulator 10 in which it is spatially modulated. This means that different positions along the strip-shaped extension of the coherent light 8 are differently modulated transversely to the propagation direction.
• the modulation takes place according to an individualization pattern for the hologram.
• the modulated coherent light beam 11 passes through the holographic recording material 4 and is at least partially diffracted and / or reflected at the hologram master. The reflected and / or diffracted light interferes with the light 11 penetrating the holographic recording material, thus exposing the hologram to the holographic recording material 4.
• a control unit 12 of the device 1 is designed to control a selection of one of the spectral colors of the light source 5 and moreover a relative movement between the light source 5 coherent light 8 or modulated coherent light 11 on the one hand and on the other hand, the holographic recording material 4 and the hologram master 2 to control.
• the control unit 12 is connected to a drive unit 13. In the illustrated embodiment, this is coupled to the imaging optics, ie the deflecting mirror 9, in such a way that the spatial light modulator 10 and the hologram master 2 are scanned in strips by synchronizing them via a displacement of the deflecting mirror.
• the control unit 12 is further configured such that an exposure time in the holographic recording material is adjusted in each case adapted to a spectral sensitivity of the holographic recording material 4 and to the selected spectral color of the coherent light 8, 11 used in each case for the exposure of the hologram.
• the required exposure time depends on the intensity of the coherent light and the spectral sensitivity of the holographic recording material 4.
• the control unit 12 may control either an intensity of the light source and / or a relative velocity of the scanning beam and / or an exposure time in a position of the holographic recording material 4.
• the color selection is performed according to a predetermined color pattern. This also controls the relative movement of the light relative to the recording material 4 and the hologram master 2. The relative movement preferably takes place stepwise.
• the control unit 12 comprises a calculation unit 14, which is designed to convert information about a primary feature with a unique, but irreversible calculation algorithm into the predetermined color pattern.
• the predetermined color pattern indicates a color sequence of the various spectral colors as well as an extension of the differently colored areas of the color pattern.
• the predetermined color pattern is calculated from the individualization pattern, or a portion thereof, that the control unit uses to drive the Spatial Light Modulator to individualize the hologram.
• the hologram 15 comprises a name 16, a pictorial representation of a face 17 (passport photo) and a structure 18, exemplarily embodied as a square, as individualization features. Together, these individualization features form an individualization pattern. Individual components, for example the structure 18, can be identical for a plurality of manufactured holograms, which are produced, for example, for passports of different persons, and represent, for example, a coat of arms.
• the hologram 15 is subdivided into a number of strip-shaped regions 19 which have different spectral colors which are characterized by letters R for red, G for green and B for blue arranged over the regions 19.
• the excellent direction 20 coincides with a scanning direction 22 (see FIG. 1), along which the coherent light 11 has preferably exposed the hologram into the holographic recording material 4 in a stepwise manner.
• the color pattern defined by the regions 19 is calculated on the basis of the individualization pattern or a part of the individualization pattern, then it can be verified whether the color pattern belongs to the visible individualization pattern or if the hologram has not been produced correctly and thus represents a forgery. It turns out that two or more than three colors and / or other than the colors specified here can be used, in particular colors in the UV or IR spectral range.
• FIG. 3 schematically shows a method for producing a security document as a block diagram, which comprises a method for producing a hologram.
• a hologram master is first provided 31.
• this may comprise the unique step of producing a holography of a ground glass 32.
• Such a preparation is described by way of example in EP 0 896 260 A2.
• a transmission hologram of the ground glass is imaged into a transmission hologram with different spectral wavelengths (colors).
• the transmission hologram is also reconstructed for the plurality of spectral wavelengths so that the reconstruction into another holographic recording material takes place and is used for generating a reflection hologram of the ground glass for the different spectral wavelengths (colors).
• a reflective sawtooth-like structure can be produced, which is described by way of example in DE 20 2007 06796 U1.
• the mirrored sawtooth surfaces have dimensions that are large against the wavelengths of light to be used to make the hologram.
• Such sawtooth-like structure fulfills as hologram master a comparable function as a hologram of a ground glass.
• a holographic recording material is arranged 33 in front of the provided hologram master.
• an individualization pattern 34 is detected.
• the individualization pattern or parts thereof may be used as the primary feature which is calculated to compute a color pattern with a unique but irreversible computational algorithm. If the individualization pattern is not to be used as a primary feature, a primary feature may be provided prior to computing the given color pattern 36. Alternatively, the color pattern can also be specified or recorded directly.
• one of several different spectral colors is selected 37. Monochromatic coherent light of the selected spectral color is generated by means of a light source 38. As a rule, the light is generated in a laser which already generates monochromatic light.
• a selection of the spectral colors can be effected by a so-called tunable laser, which can generate monochromatic light selected from a spectral range, via a drive. If the light of different spectral colors is generated by means of several lasers, these can be operated switched. A selection can also be made via optical elements, apertures, a color wheel or the like. Alternatively or additionally, one or more tunable lasers may be used. These can be realized, for example, using optical parametric oscillators.
• the monochromatic coherent light of the selected spectral color is modulated by means of a spatial light modulator, for example an LCD display which is driven by the individualization pattern 39.
• the modulated coherent light transmits the recording material and diffracts a portion of the light at the hologram master or reflects so that the hologram is exposed via interference in the holographic recording material.
• An exposure is carried out to match the spectral sensitivity of the holographic recording material according to the spectral color used 40.
• a relative shift of the optical path (of light) relative to the recording material and hologram master is carried out 41 and 42 checks whether the hologram, ie the color pattern is completed. If this is not the case, the method with the method step 37 selecting a spectral color on the basis of Color pattern continued. On the other hand, if the hologram is completely exposed, the holographic recording material is developed 43.
• the finished hologram is then integrated into a security document 44.
• a security document 44 For this purpose, it is preferably arranged between layers 45, which are then laminated to a document body 46.
• Further security features can be integrated into the security document.
• the primary feature and / or the predetermined color pattern in the security document body is separated from the hologram, i. This ensures that the color pattern or primary feature by which the color sample can be calculated is provided for verification with the security document. If the individualization pattern or a part thereof is used to calculate the given color pattern, the separate coding in the security document may be omitted.
• the method is now preferably continued beginning with the method step arrangement of the holographic recording material in front of the hologram master 33. This is done, for example, by moving a new section of holographic recording material wound on a roll in front of the hologram master.
• the hologram master is integrated in a drum over which the holographic recording material is guided.
• the relative movement between the holographic recording material and the hologram master on the one hand and, on the other hand, the coherent (possibly modulated) light is effected by a rotational movement of the drum.
• the holographic recording material and the hologram master are in series at the exposure location relative to one another.
• FIG. 4 shows an exemplary embodiment of a device 50 for verifying a hologram 51 or a security document 52, in which the hologram 51 is integrated.
• the device 50 for verification comprises a light source 53 which can emit light of the different spectral colors at the same time or with a time delay.
• the light source 53 is arranged relative to the hologram 51 so that the reconstructed hologram can be spectrally detected by a detection unit 54, which is embodied, for example, as a camera or CCD.
• a controller 55 controls both the light source and the detection unit.
• the control unit comprises an evaluation unit 56, which is based on the spectrally resolved detected hologram 51 can determine the color pattern.
• the controller 55 includes a computing unit 57 that is capable of calculating the associated color pattern from a primary feature, such as the detected individualization pattern.
• a comparison unit 58 compares the determined color pattern with the calculated color pattern. If these two agree, then the hologram 51 or this security feature of the security document is considered authentically verified.
• the device 50 can comprise a further detection unit 59, which is designed, for example, as a chip card reader, in order to read out information, for example from a chip 60 of the security document 52 in the example shown.
• the information read out of the chip 60 may comprise, for example cryptologically encrypted, the color pattern which the correct hologram 51 of the security document 52 should have. It is also possible for the chip 60 to contain information about a primary feature which is used to calculate the color pattern in order to compare the calculated color pattern with the observed color pattern in order to carry out the verification of the hologram 51 or the security document 52.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Computer Security & Cryptography (AREA)
• Holo Graphy (AREA)
• Credit Cards Or The Like (AREA)
• Diffracting Gratings Or Hologram Optical Elements (AREA)

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• 2007
  • 2007-10-31 DE DE102007052951.3A patent/DE102007052951B4/de active Active
• 2008
  • 2008-10-31 EP EP14153284.6A patent/EP2738624B1/de active Active
  • 2008-10-31 EP EP08844653.9A patent/EP2208117B1/de active Active
  • 2008-10-31 WO PCT/EP2008/009346 patent/WO2009056356A2/de not_active Ceased
  • 2008-10-31 JP JP2010531468A patent/JP5756632B2/ja active Active

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