EP3184319B1 - Élément de sécurité pour papiers de sécurité, documents de valeur ou analogues et procédé de fabrication d'un élément de sécurité - Google Patents

Élément de sécurité pour papiers de sécurité, documents de valeur ou analogues et procédé de fabrication d'un élément de sécurité Download PDF

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Publication number
EP3184319B1
EP3184319B1 EP16002760.3A EP16002760A EP3184319B1 EP 3184319 B1 EP3184319 B1 EP 3184319B1 EP 16002760 A EP16002760 A EP 16002760A EP 3184319 B1 EP3184319 B1 EP 3184319B1
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EP
European Patent Office
Prior art keywords
micro
grating
sub
reflector
reflectors
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
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EP16002760.3A
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German (de)
English (en)
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EP3184319A1 (fr
Inventor
Hans Lochbihler
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Giesecke and Devrient Currency Technology GmbH
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Giesecke and Devrient Currency Technology GmbH
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Publication of EP3184319A1 publication Critical patent/EP3184319A1/fr
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Classifications

    • 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
    • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
    • B42D25/23—Identity cards
    • 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
    • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
    • B42D25/24—Passports
    • 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
    • B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
    • B42D25/29—Securities; Bank notes
    • 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
    • B42D25/324—Reliefs
    • 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
    • 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
    • B42D25/342—Moiré effects
    • 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
    • B42D25/351—Translucent or partly translucent parts, e.g. windows
    • 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
    • B42D25/36—Identification or security features, e.g. for preventing forgery comprising special materials
    • B42D25/373—Metallic materials
    • 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
    • B42D25/40—Manufacture
    • B42D25/405—Marking
    • B42D25/425—Marking by deformation, e.g. embossing
    • 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
    • B42D25/40—Manufacture
    • B42D25/405—Marking
    • B42D25/43—Marking by removal of material

Definitions

  • the invention relates to a security element for an object to be protected, such as.
  • a security paper, document of value or the like comprising a plurality of microreflectors arranged in a pattern and a plurality of microstructures which together with the microreflectors produce an image perceptible by a viewer.
  • the invention further relates to a security paper or document of value.
  • the invention also relates to a method for producing a security element for an object to be protected, such.
  • a security paper, document of value or the like wherein on a substrate a plurality of microreflectors arranged in a pattern and a plurality of microstructures are formed, which together with the microreflectors produce an image perceptible by a viewer.
  • Items to be protected are often provided with a security element that allows verification of the authenticity of the item and thus serves as protection against unauthorized reproduction.
  • Such items are, for example, security papers, identification or value documents (such as banknotes, chip cards, passports, identification cards, identity cards, shares, bonds, certificates, vouchers, checks, tickets, credit cards, health cards) as well as product security elements such. Labels, seals and packaging. It can also be products themselves, such as a capsule of a drug for which fakes are to be feared.
  • This synthetic image has properties (for example, an ortho-parallactic effect) that are not reproducible by simply copying the images.
  • the focusing elements can be designed as microlenses or microreflectors. The latter construction is the subject of the publications WO 2010/136339 A2 and the WO 2011/012460 A2 ,
  • microimages are a greatly reduced form of at least a partial section of the synthetic image. They are formed for example by the image content corresponding relief surfaces which are filled with color, or which otherwise have light-absorbing properties.
  • microimages and focusing elements require a distance between microimages and focusing elements, which corresponds approximately to the focal length of the focusing elements.
  • this requirement is generally met by the fact that microimages and microfocusing elements are arranged on opposite sides of a film whose thickness corresponds approximately to the focal length of the focusing elements. This procedure requires a double-sided embossing of the film in very exact register each other. This is expensive and therefore disadvantageous.
  • the publication WO 2012/156049 A1 is concerned with a two-dimensionally periodic, color-filtering grating which has a contiguous high-index base layer defining a lattice plane. Above the base layer, the grating has a two-dimensionally regular pattern of individual high refractive surface elements which has a periodicity between 100 nm and 800 nm in at least two directions which are parallel to the grating plane.
  • a security element with a flat, transparent body which, in a first area, has a basic element structure which conveys different color impressions in plan view of the body from the front and the back.
  • the publication WO 2011/066992 A1 relates to a security element with a carrier whose top is height-modulated, and having a multi-layer structure acting as a color filter, which is formed on the height-modulated upper side and thus also height-modulated.
  • the publication DE 10 2012105 571 A1 describes a decorative element with a microstructure, which generates an optical effect in reflected light and / or transmitted light.
  • the microstructure is designed in such a way that a color is generated by interference of the light reflected at a base surface and element surfaces in incident light and / or in particular by interference of the light transmitted through the element surfaces and the base surfaces in transmitted light.
  • the generic document WO 2014/012667 A1 also deals with a security element. It consists of a large number of microreflectors arranged in a pattern, at the bottom of each of which there is a reflective grating, which diffracts incident radiation and directs it towards the microreflector, which then reflects it back to the viewer. Thus, incident light from the array of micromirrors and gratings is completely reflected to the viewer. The grids bend the incident light in the first diffraction order. By varying the relative position of microreflector to grating in the pattern, an image can be generated. Proceeding from this, the object of the invention is to achieve greater protection against forgery and applicability in the case of a security element, a security paper or document of value as well as in a production method for these objects.
  • the invention provides a security element as defined in independent claim 1 for an article to be protected, such as a security paper, a document of value or the like.
  • the security element comprises a substrate having a plurality of microreflectors arranged in a pattern and a plurality of microstructures which, together with the microreflectors, produce an image perceptible by a viewer.
  • Each microstructure is designed as a sub-wavelength grating and assigned to one of the microreflectors, whereby grating reflectors comprising in each case a microreflector and at least one sub-wavelength grating are formed.
  • Each subwavelength grid is designed to that visible radiation, ie light incident through an aperture of the micro-reflector from the half-space, diffractively diffracts into a zeroth reflection diffraction order, wherein preferably for each grating reflector, the sub-wavelength grating and the microreflector are matched to one another such that the microreflector at least a part of radiation diffracted by the sub-wavelength grating into the zeroth reflection diffraction order is reflected back into the half-space as re-radiation.
  • the sub-wavelength grating is formed as a semi-transparent sub-wavelength grating which transmissively diffracts a second portion of the visible radiation incident through the aperture of the microreflector from the half space into a zeroth transmission diffraction order.
  • the subwavelength grating and the microreflector are matched to one another in such a way that the subwavelength grating transmits the radiation incident through the aperture of the microreflector from the half space and reflected by the microreflector in the zeroth transmission diffraction order through the substrate.
  • the sub-wavelength grating is formed as an opaque sub-wavelength grating.
  • the subwavelength gratings are configured with structures whose period is smaller than the wavelength of the visible light spectrum. They are further designed so that they bend the majority of radiation coloring in the zeroth order of diffraction. If higher diffraction orders occur for certain angles of incidence in the short-wave wavelength range, only a small portion of the incident radiation is diffracted into these orders. For example, get 50%, 60% or 70% of the incident radiation in the zeroth order of diffraction, either in reflection or in transmission.
  • the subwavelength grating can be designed in such a way that approximately half of the radiation is reflected and the other half is transmitted, and furthermore a small proportion of the radiation is absorbed. Other divisions are possible.
  • the sub-wavelength grating is semi-transparent in this sense and causes a color in reflection and transmission. For certain parameters, the proportion of radiation that is absorbed may also be dominant.
  • the reflection and transmission properties of the subwavelength grating are particularly dependent on the wavelength of the incident radiation. In particular, only radiation in a specific wavelength range in the zeroth diffraction order is diffracted or reflected diffracted. Thus, it is possible to determine the color or the color appearance of the image generated by the grating reflector in reflection and / or transmission.
  • the reflection and transmission properties of the subwavelength grating also depend on the profile geometry and on the material properties of the subwavelength grating.
  • the transmission takes place through the substrate, which is therefore preferably at least partially transparent or translucent for the radiation.
  • the substrate is preferably made transparent at least in the region of a bottom of the grating reflectors, in particular the substrate is completely transparent, for example a transparent film.
  • the substrate may be opaque, for example, coated with a sub-wavelength absorbing grating to provide a black background for the image.
  • the subwavelength grating and the microreflector are in particular arranged such that the radiation transmitted or reflected by the first or higher diffraction order is not reflected or transmitted as far as possible to the microreflector or at such shallow angles that the microreflector rejects radiation from the higher diffraction orders compared to the one in the zeroth Diffraction order transmitted only to a lower intensity component or reflected in the half space.
  • the security element is characterized in particular by the fact that the security element displays an image or several images to an observer, both when it is in the same half-space as the security element illumination (reflected image or supervisory image) and when the illumination of the security device Security element and the observer with respect to the security element are located in two different half-spaces (transmitted image or transparency).
  • the security element thus shows an image from both sides, the images being the same or different, e.g. B. with regard to a color impression can be.
  • the sub-wavelength grating of the security element is not used in advantageous embodiments for the absorption of radiation, but for the reflection and transmission of radiation.
  • the part of the radiation absorbed by the sub-wavelength grating and / or the security element is extremely small, for example less than 50% of the incident radiation.
  • the absorption ratio is greater for a sub-wavelength grating than for a first-order diffraction grating, since electromagnetic resonances occur here for specific wavelengths which lead to light absorption, as for example in the documents DE 10 2011101635 A1 and DE 10 2009 056 933 A1 described.
  • the sub-wavelength grating is used only for the reflection of radiation and acts as a so-called subtraction color filter.
  • the (opaque) sub-wavelength grating absorbs radiation in a certain wavelength range in the visible part of the radiation spectrum, the remaining part of the radiation spectrum is reflected. Thus, for example, if the blue portion of the radiation is absorbed, the subwavelength grating appears in reflection in the complementary color of blue.
  • the diffracted back and transmitted transmission radiation may optionally be mirrored prior to diffraction (transmission or transmission) or after or before diffraction (reflection) at the micro-reflector. In all cases, the direction in which it is emitted, the angle of radiation and the color of the formation of the grating reflector depends. By arranging differently configured grating reflectors in the pattern, colored symbols or images can be generated, both in a plan view and in a transparent view.
  • the portion of the incident radiation deflected by the grating reflector is responsible for producing the reflected (top view) or transmitted (see through) image. Due to the design of the grating reflector such that as much light is deflected, a particularly light-intensive image can be generated.
  • the degree of deflection depends inter alia on the diameter of the aperture. The larger the diameter of the Aperture, the smaller the angular range in which the incident light is deflected by the grating reflector. On the other hand, as the diameter of the aperture increases, the convergence of the laterally deflected light increases. Thus, although a larger diameter lattice reflector of the aperture is capable of deflecting light from a wider range of angles, the divergence of the deflected light is also greater, which reduces the intensity of the image.
  • the size of the deflection also depends on the depth of the grating reflector, which is measured from the bottom of the grating reflector to its aperture.
  • the depth of the grating reflector increases, so does the divergence of the reflected or transmitted light.
  • the acceptance angle of the incident light and the divergence of the reflected light or transmitted light can be selected accordingly to provide for the respective security element best parameters for generating the image.
  • the image information is only achieved by the interaction of the grating reflectors in the pattern. Preference is given to multiple grating reflectors with different configurations (combination of microreflector and microstructure in the respective grating reflector) provided so that there is a difference in color or intensity between the grating reflectors, which produces a total of the perceptible image.
  • a plurality of equal grating reflectors can be arranged side by side, with their arrangement carrying the image information. In this way, for example, letters or symbols are displayed.
  • the image information is preferably generated by the security element in that each grating reflector consisting of microreflector and subwavelength grating has the function of a pixel for image generation.
  • the sublength wave gratings in combination with the microreflectors generally have strongly angle-dependent properties, it is also possible to generate parallax images as in a moire magnification arrangement. It is also possible to form stereograms, for example by appropriate alignment of the microreflectors so that some grating reflectors provide image information for the left eye, others for the right eye (corresponding to the visual angle difference).
  • grating reflectors can be combined with known structures such as holograms, micromirror arrangements and / or light-absorbing structures such as moth-eye structures or microcavities.
  • the security element can be produced in a single molding process. It is not necessary to carry out registration steps to be carried out in register with one another on different sides of a transparent film. Rather, it is possible with a single embossing process, a substrate, for. As a film to be designed so that both the structures of the microreflectors and the sub-wavelength grating are generated. The relative position (and shape) of subwavelength grating and associated microreflector is determined by the given embossing tool, so that no mutually in the register standing sequences of processing steps on the substrate are necessary. This simplifies the production.
  • the minimum thickness of the security element is not predetermined by a focal length of focusing elements.
  • the thickness is limited only by the depth of the microreflectors. This depth corresponds approximately to the height which microlenses would have for known moiré magnification arrangements, with the result that the minimum thickness of the security element is only a fraction of that of conventional security elements with moiré magnification arrangements. Nevertheless, a moiré effect can be realized equally.
  • the micro-reflectors can be configured as channel-shaped reflectors. They are then gutters, which preferably have a flat bottom. The flat floor does not necessarily have to be reflective. At the level bottom of the sub-wavelength grating is arranged, which is then also designed as a linear grating. Especially with channel-shaped reflectors, it is also possible to arrange more than one sub-wavelength grating along the channels of the reflector.
  • the micro-reflectors may be designed as a concave mirror, which preferably have a flat bottom on which the sub-wavelength grating is located. Again, the floor does not have to be reflective.
  • the planar bottom of the microreflectors can in particular be configured obliquely, so that the sub-wavelength grating tends toward the microreflector.
  • microreflectors whose bottom is not flat but, for example, arched.
  • the micro-reflectors are formed as a concave mirror, which are rotationally symmetric, for example, have the shape of the lateral surface of a spherical layer or ellipsoid layer.
  • a lateral surface is obtained when a layer is cut out of an ellipsoid or a sphere by two parallel planes which actually cut the sphere or the ellipsoid.
  • the smaller of the two parallel circular surfaces or ellipses created by the cut then represents the bottom of the concave mirror. This does not have to be mirrored.
  • microreflectors have, in addition to the bottom, a side wall which is parabolic in cross-section, straight, elliptical or formed as a hybrid form thereof.
  • the sidewall may be divided into several sections, each section being parabolic, straight, elliptical, or a hybrid form thereof. It is also possible that the individual sections are formed differently. If an aperture of hexagonal cross-section is provided, each section of a wall may correspond to the hexagonal aperture. Alternatively, the aperture can be rectangular and thus the micro-reflector cuboid, wherein each side wall in cross-section corresponding parabolic, straight, elliptical or formed as a hybrid form thereof.
  • the shape of the side wall in cross section depends in particular on the size of the microreflector and the arrangement of the subwavelength grating in the microreflector.
  • the alignment of the side walls of the individual grid reflectors makes it possible to transmit image information.
  • the sidewalls are oriented in a first direction, so that these grating reflectors are visible in a first viewing direction.
  • the side walls are aligned in a second direction, so that these grating reflectors can be seen in a second viewing direction.
  • micro-deflectors are asymmetrical in cross-section, wherein in particular a first part of the side wall is straight and a second part of the side wall is concave, in particular parabolic or elliptical.
  • the first part of the side wall and the second part of the side wall are arranged opposite each other.
  • two sections of the side wall are located opposite one another.
  • the first part of the side wall which is currently formed, may be arranged perpendicular to the ground.
  • the straight part shields a region of the bottom from the incident radiation, i. shaded, and thus does not contribute to the undeflected portion of the incident radiation. Consequently, the proportion of radiation that is deflected laterally increases.
  • each sub-wavelength grating has a grating period between 100 nm and 500 nm, particularly 240 nm to 420 nm, the sub-wavelength grating being one-dimensionally periodic or even two-dimensional can be formed periodically.
  • the grating period and the profile of the subwavelength grating depend in particular on the color which is to be reflected or transmitted in the zeroth diffraction order.
  • the microreflectors and the sub-wavelength gratings are advantageously coated with at least one metallic layer, preferably with Al, Ag, Au, Cu, Cr or an alloy containing these metals.
  • the microreflectors and the subwavelength gratings can be provided on their side facing the half space with a multilayer coating, e.g. B. as a trilayer of two superimposed metal or semiconductor layers with an intervening dielectric layer can be constructed.
  • the shape of the microreflector Due to the shape of the aperture, the shape of the microreflector is determined in particular. Thus, the arrangements of the side surfaces are given and consequently also the reflected radiation from the side walls. For example, by using a rotationally symmetrical microreflector with a circular aperture, an image can be generated in many directions. When using a cuboid microreflector with a rectangular aperture individual observation directions may be preferred. The same applies to a cylindrical microreflector with a hexagonal aperture.
  • Grid reflectors with round apertures are preferably arranged in a hexagonal pattern, since in this way the highest possible area filling can be achieved.
  • the individual grid reflectors can be formed with webs surrounding them, i. H. at least some adjacent grille reflectors then do not abut each other directly, but are separated by a web. Between the grid reflectors are thus web surfaces, which are preferably formed by flat surfaces. By coating the web surfaces and / or shaping the thickness of the substrate in the region of the web surfaces, it is possible to ensure that light incident on the web surfaces is differently reflected and / or transmitted. The effect is preferably designed to be laterally variable in order additionally to encode symbols and make them visible in transmission. This additional counterfeit security is achieved.
  • a laterally varying coating of the web surfaces is preferably realized in that the web surfaces are first provided with a coating, for example with a metallization, and this is partially removed again, for. B. by an etching process.
  • a coating for example with a metallization
  • the micro-reflectors can basically have any shape in their aperture (opening), for example square, circular or rectangular apertures.
  • the aperture has a diameter and the microreflector has a depth from the aperture to the bottom, wherein within a pattern at least one of the following properties of the grating reflectors varies to produce an image: location of the subwavelength gratings to the respective associated microreflector The diameter of the aperture, the depth of the microreflector, the orientation of the microreflector, the shape of the microreflector and / or the grating period of the subwavelength grating.
  • one or more parameters are changed between the individual grating reflectors of the pattern.
  • a region of the image can be generated by grating reflectors with a first parameter set, while a second region of the image is generated by grating reflectors with a second parameter set. In this way, for example, generate stereograms.
  • the parameters within the image may change continuously to produce moiré effects, for example.
  • the security element may in particular be designed as a security thread, tear-open thread, security strip, security strip, patch or label.
  • the security element can cover transparent areas or recesses of an object to be protected.
  • the security element can be part of a precursor that can not yet be processed to a value document, which, for example, can also have additional authenticity features (such as, for example, luminescent substances provided in the volume, etc.).
  • value documents here on the one hand understood the document having security element, on the other hand value documents can also be other documents or items that can be provided with the security element according to the invention, so they have non-copyable authenticity features.
  • Chip or security cards such. As bank or credit cards are other examples of value documents.
  • the invention relates to a defined in the independent claim 12 method for producing a security element for an object to be protected, such as.
  • a security paper, document of value or the like wherein on a substrate a plurality of microreflectors arranged in a pattern and a plurality of microstructures are formed, which together with the microreflectors produce an image perceptible by a viewer.
  • Each microstructure is formed as a sub-wavelength grating and associated with one of the microreflectors, thereby forming grating reflectors each comprising a microreflector and at least one sub-wavelength grating.
  • Each sub-wavelength grating is formed to reflectively deflect visible radiation incident through an aperture of the micro-reflector from a hemisphere into a zeroth reflection diffraction order, preferably matching the sub-wavelength grating and the microreflector for each grating reflector such that the microreflector matches Reflected radiation from the sub-wavelength grating in the zeroth reflection diffraction order reflected back radiation in the half space back.
  • the sub-wavelength grating is formed as a semi-transparent sub-wavelength grating which transmissively diffracts a second portion of the visible radiation incident through the aperture (24) of the microreflector (22) from the hemisphere into a zeroth transmission diffraction order.
  • the sub-wavelength grating and the microreflector are preferably further tuned to one another such that the sub-wavelength grating transmits the radiation incident through the aperture of the microreflector from the half-space and reflected by the microreflector in the zeroth transmission order.
  • the sub-wavelength grating is formed as an opaque sub-wavelength grating.
  • direct exposure techniques are suitable for producing the microreflectors, e.g. B. photolithographically with the help of a laserwriter.
  • the preparation can be carried out analogously to the known production method for microlenses.
  • the structure of the subwavelength gratings is generated.
  • the two processes are preferably carried out accurately in one and the same photoresist.
  • two different Belackungsvorerie are possible.
  • an exposed original can then be galvanically molded, thus producing an embossing stamp.
  • the structure is replicated via a stamping process, for example in UV varnish on film.
  • a nanoimprint method can be used. More elaborate methods of original manufacture, such as electron beam or focused ion beam exposure techniques, allow for even finer geometry design and are therefore particularly suitable for the production of subwavelength gratings.
  • the manufacturing method according to the invention can be designed so that the described preferred embodiments and embodiments of the security element are produced.
  • the safety element 12 is made of a substrate 14, for example a transparent film, on whose upper side (the term is to be understood purely by way of example and is not intended to indicate a preferred direction) an embossed structure is formed.
  • the embossing structure comprises a plurality of microreflectors 22, which in the embodiments of the Fig. 1 to 4 are formed as elliptical reflectors with a flat bottom 16. In other embodiments, for example, in which the Fig. 5 and 6 the micro-reflectors are designed in other geometries, in particular not rotationally symmetrical.
  • Each grid reflector 10 thus has the bottom 16 and at least one side wall 18.
  • a semi-transparent sub-wavelength grating 20 is provided on the bottom 16 of the grating reflector 10.
  • the at least one side wall 18 and the bottom 16 form the microreflector 22, which is open to the top and thus to a half space through an aperture 24 with a diameter a.
  • the distance from the bottom 16 to the aperture 24 determines the depth t of the grating reflector 10.
  • the substrate 14 is at least partially transparent in the region of the bottom 16.
  • the side wall 18 of Fig. 1 illustrated grid reflectors 10 is designed parabolic in cross section. Furthermore, here the grating reflector 10 is designed rotationally symmetrical.
  • the grating reflectors 10, which are in Fig. 1a and 1b are shown to have the same diameter a of the aperture 24, but differ in their depth t.
  • the ratio of the diameter a of the aperture 24 to the depth t of the grating reflector 10 is 0.8 in Fig. 1a and 0.55 in Fig. 1b ,
  • the proportion of the radiation incident from the half-space, which falls on the sub-wavelength grating 20, is reflected directly there and transmitted to a second part.
  • the other remainder of the visible radiation incident to be reflected by the micro-reflector 22 onto the sub-wavelength grating 20 is also partially diffracted by the sub-wavelength grating 20 in zero diffraction order and partially transmitted. Reflection in the zeroth reflection diffraction order means that the angle of incidence is equal to the angle of reflection, but z. B. the color properties of the diffraction are dependent on the direction of the incident light.
  • the proportion of light which is first reflected at the micro-reflector 22 is thus reflected differently at the sub-wavelength grating and transmitted as the directly incident light component.
  • the incident radiation is deflected laterally with respect to the angle of incidence, so that it creates a visible image for the observer.
  • the amount of light deflected laterally can be increased by providing an asymmetrical grating reflector 10 as shown in FIG Fig. 2a and 2b is shown.
  • a first part 26 of the side wall 18 is straight in cross-section and is in particular perpendicular to the bottom 16.
  • a second part 28 of the side wall 18, which is arranged opposite the first part 26, is as in FIG Fig. 1 parabolic shaped.
  • the ratio of the diameter a of the aperture 24 to the depth t of the grating reflector 10 is 1 in Fig. 2a and 0.53 in Fig. 2b ,
  • Fig. 2a and 2b is represented by the left light beam
  • the first portion 26 of the side wall 18 shadows a portion of the sub-wavelength grating 20 in the incident radiation. This increases the proportion of the light which is deflected by the grating reflector 10.
  • Fig. 3 shows three different depth grating reflectors 10 with a constant diameter a of the aperture 24 and the same sub-wavelength grating 20 at the bottom 16 of the grating reflector 10.
  • results for the grating reflector 10 of Fig. 3b an aspect ratio of 1.
  • the marginal rays of the incident and the diffracted radiation are drawn, which are first diffracted at the sub-wavelength grating 20 in the zeroth order and then deflected by the side wall 18 of the microreflector 22.
  • the transmitted radiation is in Fig. 3 not shown because the semi-transparent sub-wavelength grating 20 transmits the drawn, incident light without deflection.
  • the comments on the FIGS. 3 and 4 also apply by way of example to such embodiments.
  • the rays each relate to a fixed point of incidence on the subwavelength grating 20.
  • the acceptance angle of the incident light and the light scattering depend on the depth t, as shown by way of example in the table below.
  • Depth t Acceptance angle of incident light Divergence of the reflected light 0.3 12.5 ° 20.5 ° 0.4 11.0 ° 16.3 ° 0.5 9.5 ° 15.1 °
  • the numbers indicate that as the depth t of the microreflector 22 increases, the divergence of the deflected radiation decreases; H. is focused to the viewer, since the exit angle describes the bundling.
  • the radiation reflected at the subwavelength grating 20 and at the microreflector 22 undergoes significant scattering. Furthermore, the acceptance angle of the incident light and the divergence of the reflected light decrease for increasing depths t of the micro-reflector 22. Finally, it should be mentioned that all the impact points on the sub-wavelength grating 20 must be considered to characterize the overall scattering of a grating reflector 10.
  • Fig. 4 The edge rays of the incident and the diffracted radiation are also drawn, which are first diffracted at the sub-wavelength grating 20 in the zeroth order and then deflected by the micro-reflector 22.
  • the impact point selected in this example is shifted to the left with respect to the symmetry axis of the micro-reflector 22.
  • the acceptance angles of the incident light and the light scattering of the reflected light are summarized in the following table: Diameter a Acceptance angle of incident light Divergence of the reflected light 0.3 17.0 ° 30.1 ° 0.4 15.5 ° 25.1 ° 0.5 14.0 ° 21.5 °
  • the variation of the diameter a of the aperture 24 also leads to a variation of the acceptance angle of the incident light and to a change in the divergence of the reflected light.
  • the pattern of many juxtaposed grid reflectors 10 can be used to represent subjects in a security element 12. It is z. B. two variants of structural geometries, preferably a different reflector geometry, in the respective areas before.
  • Fig. 5 shows such a varied arrangement of grating reflectors 10, in which the depth t is selected differently in the areas I and II.
  • the diameter of the aperture 24 of the microreflectors 22 is designated by a
  • the extent of the subwavelength gratings 20 is denoted by b.
  • the depth t of the microreflectors 22 in the regions I and II is t 1 and t 2, respectively.
  • the pattern of the grating reflectors 10 allows a variety of different reflector geometries. Exemplary are the micro-reflectors 22in Fig. 5a with a parabolic and in Fig. 5b represented with a conical shape.
  • the microreflectors 22 may have a non-rotationally symmetric and / or asymmetric shape in cross section. Examples of unilaterally parabolic microreflectors 22 and microreflectors 22 having a trapezoidal cross section without curvature are shown in FIG Fig. 6 shown.
  • Fig. 7 shows some examples of grating reflectors 10 having the following aperture shapes: square, circular and hexagonal.
  • the grid reflectors 10 of Fig. 7a and Fig. 7b are arranged orthogonally.
  • An optimal area coverage is achieved by a hexagonal arrangement, as in Fig. 7c is shown.
  • the location of the subwavelength gratings 20 within the individual microreflectors 22 may be shifted laterally.
  • a continuous shift of the subwavelength gratings 20 relative to the aperture 24 of the microreflectors 22 can be used in particular for generating moiré effects, stereoscopic effects or running effects.
  • Stereograms by means of the grating reflectors 10 is based on the in Fig. 8 illustrated example explained. Stereograms require at least two images, one for left-eye perception and the other for right-eye perception. Such stereograms can be generated by the grating reflectors 10 described herein both in reflection and in transmission.
  • Fig. 8 shows a security element 12 in the form of a stereogram.
  • the area of the two letters "AB” is filled with a plurality of grid reflectors 10.
  • the surrounding background contains a homogeneous sub-wavelength grating 20.
  • the incident light is directed in the exemplary embodiment by a semicylindrical reflector geometry in different directions.
  • the grid reflectors 10 in the letter “A” are oriented so that they preferentially direct the light to the right eye.
  • the light reflected by the grille reflectors in the letter "B” is primarily perceived by the left eye.
  • the orientation is determined by the side walls 18 of the micro-deflectors 22. With a correspondingly small pixelization, these two symbols can also be nested one inside the other.
  • the grating reflectors described here provide 10 a wide range of possible designs and symbols.
  • the desired color is accomplished by the appropriate selection of the grating period of the sub-wavelength grating 20.
  • the pattern with many grating reflectors 10 also colored symbols or images can be generated, which are visible at a certain angle.
  • at least one of the above-mentioned parameters of the grating reflectors 10 in the pattern is laterally varied. Since the grating reflectors 10 have strongly angle-dependent properties, in particular parallax images can also be generated thereby. As a result, both parallactic movements and spatial effects can be realized.
  • Fig. 9 schematically shows a security element 12 with motifs, which are formed by a pattern of grating reflectors 10 in front of a homogeneous background. This surrounding area is filled in the exemplary embodiment with a homogeneous sub-wavelength grating 20. Due to the light deflection through the grating reflectors, the motif "star" is visible in oblique view in transmission, while the background appears dark ( Fig. 9a ).
  • Fig. 9b shows a motif with the letters "A” and "B", which are formed by differently shaped asymmetric grating reflectors 10.
  • the curved side wall 18 (second part 28; Fig. 2 ) at the letter “A” below, at the letter “B”, the second part 28 of the side wall 18 in the micro-reflector 22 is arranged above.
  • the motifs with differently oriented grating reflectors 10 can be nested. The different motifs can then be perceived one after the other and depending on the subject at the same location of the security element when tilting a pattern designed in this way.
  • Fig. 9 shown security element 12 is used in particular in see-through windows of banknotes use. However, it is also possible to use only the reflection properties of this structure, for example for a security thread or a security strip (eg LEAD (Longlasting Economical Anticopy Device) strip).
  • a security thread or a security strip eg LEAD (Longlasting Economical Anticopy Device) strip.
  • subwavelength grating 20 not only one-dimensional periodic gratings can be used. Also, the subwavelength gratings need not be combined with microreflectors 22 that are curved in the same spatial direction. There are also sub-wavelength grating 20 conceivable, which are rotated about an axis of symmetry of the micro-reflector 22, wherein the rotation is varied within the pattern.
  • cross gratings are particularly suitable, the grating period preferably being perpendicular to the curvatures of a microreflector having a rectangular aperture 24.
  • Circular gratings are particularly suitable for reflectors with round apertures 24.
  • hybrid forms or elliptical subwavelength gratings 20 in microreflectors 22 with elliptical apertures 24 are possible.
  • grating reflectors 10 formed in each case from subwavelength grating 20 and microreflector 22 are arranged next to one another, their configuration varying laterally in order to form an image, for example, as a colored symbol.
  • the variation of the diffraction characteristics of the subwavelength gratings 20, or the position of the subwavelength gratings 20 to the respective associated microreflector 22 or the reflection characteristic of the microreflectors 22, the alignment of the microreflectors 22, or the grating period of the subwavelength grating 20, or a combination thereof, causes a color or intensity contrast in the Motive.
  • the web surfaces are preferably formed by flat surfaces. In an exemplary construction, the web surfaces are laterally structured such that some web surfaces are provided with a metallization, but others are not.
  • the security element 12 is structured in this way in two areas that differ in their reflection behavior and also in their transmission behavior. As a result of the lateral structuring of the metallization, additional information can thus be coded in the security element 12. Instead of a metallization It is also possible to use a different reflection layer.
  • an absorption layer can also be formed.
  • the lateral structuring of the web surfaces then has no effect on the reflection behavior, but on the transmission behavior.
  • the security element 12 of the Fig. 1 used principle provides a large building block with which patterns or symbols can be designed by grating reflectors 10.
  • the variation of the grating reflectors 10 in the pattern can be realized by many parameters.
  • the structure of the security element 12 can be made very easily in a single embossing process. All you need is a corresponding embossing tool that has a corresponding negative shape for each grid reflector 10, which thus generates both the microreflectors 22 and the sub-wavelength gratings 20.
  • the subwavelength gratings 20 must be precisely formed in the embossing tool. Specifically, the fabrication of the original of the sub-wavelength grating 20 can be accomplished by electron beam writing or interferometric techniques.
  • the microreflectors 22 typically have a depth t of 2 to 30 microns, a particularly preferred range is between 5 and 20 microns. Lower depths t are advantageous both with regard to the production of the embossing tool and the subsequent duplication.
  • the sub-wavelength grating 20 is optically particularly effective when at least 4 to 10 grating periods can be accommodated at the bottom 16. This gives one lower limit for the size of the microreflectors 22 before.
  • An upper limit arises when one wants to use the grating reflectors 10 as pixels, which should naturally be as small as possible and in particular should no longer be resolved with an unarmed eye.
  • as flat an embossing as possible is advantageous in copying.
  • the microreflectors 22 are first produced in a variant, for example photolithographically by direct laser writing. Independently, the structure of the subwavelength gratings 20 is generated. These two processes are preferably carried out accurately in one and the same photoresist, which is the basis for the embossing tool as a template. Alternatively, two different Belackungsvor réelle are possible.
  • micro-reflectors 22 are imprinted in the direct exposure process with a laserwriter, so that the subwavelength lattice 20 is exposed in the middle of the individual microreflectors after development.
  • the laserwriters used can work with 2-photon absorption processes. It is then possible to generate microreflectors 22, such as sub-wavelength gratings 20, in a single process.
  • the template produced for the embossing tool is now copied electroplated or in a nanoimprint process.
  • a plurality of security elements 12 are usually to be produced in one embossing step in the embossing process of a film, it is preferable to provide a plurality of adjacent stamp elements in the embossing tool, each of which has been produced from a template in the above-described manner.
  • the embossed film is preferably coated with an opaque metal layer.
  • a metal layer For this purpose, sputtering, electron beam evaporation or thermal evaporation come into question.
  • Particularly suitable metals are aluminum, silver, gold, nickel or chromium or alloys of these materials. But there are also multi-layer structures in question, which contain at least one layer of metallic material. The thicknesses of the metal layer are between 20 and 100 nm.
  • the metal surface is preferably coated with a protective layer or laminated with a cover film.
  • a corresponding coating is preferably first applied to all web surfaces and then removed again from some web surfaces.
  • the removal is performed by demetallization.
  • an etching process or the metal transfer process according to WO 2011/138039 A1 come into use. It is also possible to remove the layer, for example demetallization with the aid of ultrashort pulse lasers and the use of a writing laser beam.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Business, Economics & Management (AREA)
  • Accounting & Taxation (AREA)
  • Finance (AREA)
  • Diffracting Gratings Or Hologram Optical Elements (AREA)
  • Credit Cards Or The Like (AREA)

Claims (21)

  1. Élément de sécurité pour un objet à protéger, lequel possède un substrat (14) comportant plusieurs microréflecteurs (22) et microstructures disposés en un modèle,
    - chacune des microstructures (20) étant associéE à l'un des microréflecteurs (22), ce qui forme plusieurs réflecteurs en grille (10) comportant respectivement un microréflecteur (22) et au moins l'une des microstructures (20),
    - chacune des microstructures (20) étant configurée de telle sorte qu'elle diffracte avec réflexion le rayonnement visible qui est incident à travers une ouverture (24) du microréflecteur (22) depuis un espace semi-infini,
    - les réflecteurs en grille (10) disposés dans le modèle générant une image perceptible par un observateur, et
    - chaque microstructure étant réalisée sous la forme d'une grille à sous-longueurs d'onde (20) qui diffracte avec réflexion une première partie du rayonnement visible qui est incident à travers l'ouverture (24) du microréflecteur (22) depuis l'espace semi-infini, caractérisé en ce que
    chacune des grilles à sous-longueurs d'onde (20) diffracte la première partie dans un zérotième ordre de réflexion par diffraction.
  2. Élément de sécurité selon la revendication 1, caractérisé en ce que la grille à sous-longueurs d'onde (20) est réalisée sous la forme d'une grille à sous-longueurs d'onde semi-transparente qui diffracte avec transmission une deuxième partie du rayonnement visible qui est incident à travers l'ouverture (24) du microréflecteur (22) depuis l'espace semi-infini, chacune des grilles à sous-longueurs d'onde (20) diffractant la deuxième partie dans un zérotième ordre de transmission par diffraction.
  3. Élément de sécurité selon la revendication 2, caractérisé en ce que dans chaque réflecteur en grille (10), la grille à sous-longueurs d'onde (20) et le microréflecteur (22) sont accordés l'un sur l'autre de telle sorte que la grille à sous-longueurs d'onde (20) transmet le rayonnement incident à travers l'ouverture (24) du microréflecteur (22) depuis l'espace semi-infini et réfléchi par le microréflecteur (22) dans le zérotième ordre de transmission par diffraction.
  4. Élément de sécurité selon la revendication 1, caractérisé en ce que la grille à sous-longueurs d'onde (20) est réalisée sous la forme d'une grille à sous-longueurs d'onde opaque.
  5. Élément de sécurité selon l'une des revendications 1 à 4, caractérisé en ce que dans chaque réflecteur en grille (10), la grille à sous-longueurs d'onde (20) et le microréflecteur (22) sont accordés l'un sur l'autre de telle sorte que le microréflecteur (22) réfléchit au moins partiellement en retour dans l'espace semi-infini sous la forme d'une rétroréflexion le rayonnement diffracté par la grille à sous-longueurs d'onde (20) dans le zérotième ordre de réflexion par diffraction.
  6. Élément de sécurité selon l'une des revendications 1 à 5, caractérisé en ce que les microréflecteurs (22) sont respectivement réalisés sous la forme de miroirs creux ou de rainures munis d'un fond plat (16), la grille à sous-longueurs d'onde (20) étant disposée sur le fond plat (16), les microréflecteurs (22) possédant de préférence une paroi latérale (18) à côté du fond (16), laquelle présente une configuration de section transversale de forme parabolique, droite, elliptique ou une forme mélangée de celles-ci.
  7. Élément de sécurité selon l'une des revendications précédentes, caractérisé en ce que les microréflecteurs (22) sont asymétriques en section transversale et possèdent un fond (16) et au moins une paroi latérale (18), une première partie (26) de la paroi latérale (18) étant notamment droite et une deuxième partie (28) de la paroi latérale (18) étant concave, notamment configurée de forme parabolique ou elliptique, notamment en ce qu'une première partie (26) de la paroi latérale (18) est perpendiculaire au fond (16).
  8. Élément de sécurité selon l'une des revendications précédentes, caractérisé en ce que chaque grille à sous-longueurs d'onde (20) possède une période de grille entre 100 nm et 500 nm, notamment entre 240 nm et 420 nm.
  9. Élément de sécurité selon l'une des revendications précédentes, caractérisé en ce que les microréflecteurs (22) et les grilles à sous-longueurs d'onde (20) sont revêtus au niveau de leur côté faisant face à l'espace semi-infini d'au moins une couche métallique, de préférence avec de l'Al, de l'Ag, de l'Au, du Cu, du Cr ou d'un alliage contenant ces métaux, et/ou en ce que les microréflecteurs (22) et les grilles à sous-longueurs d'onde (20) possèdent, au niveau de leur côté faisant face à l'espace semi-infini, un revêtement à triple couche composé de deux couches en métal ou en semiconducteur disposées l'une au-dessus de l'autre avec une couche diélectrique se trouvant entre celles-ci.
  10. Élément de sécurité selon l'une des revendications précédentes, caractérisé en ce que l'ouverture (24) possède un diamètre (a) et le microréflecteur (22) possède entre l'ouverture (24) et un fond (16) une profondeur (t), au moins l'une des propriétés suivantes des réflecteurs en grille (10) variant à l'intérieur du modèle afin de générer l'image : position des grilles à sous-longueurs d'onde (20) par rapport au microréflecteur (22) respectivement associé, diamètre (a) de l'ouverture (24), profondeur (t) du microréflecteur (22), orientation du microréflecteur (22), forme du microréflecteur (22) et/ou période de grille de la grille à sous-longueurs d'onde (20), la propriété des réflecteurs en grille (10) à l'intérieur du modèle variant de préférence en continu de telle sorte que l'image est générée au moyen d'un effet de moiré.
  11. Papier de sécurité ou document de valeur, caractérisé par un élément de sécurité (12) selon l'une des revendications 1 à 10.
  12. Procédé de fabrication d'un élément de sécurité (12) pour un objet à protéger, plusieurs microréflecteurs (22) et plusieurs microstructures disposés en un modèle étant formés sur un substrat (14),
    - chacune des microstructures (20) étant associée à l'un des microréflecteurs (22), ce qui forme plusieurs réflecteurs en grille (10) comportant respectivement un microréflecteur (22) et au moins l'une des microstructures (20),
    - chacune des microstructures (20) étant configurée de telle sorte qu'elle diffracte avec réflexion le rayonnement visible qui est incident à travers une ouverture (24) du microréflecteur (22) depuis un espace semi-infini,
    - les réflecteurs en grille (10) disposés dans le modèle générant une image perceptible par un observateur, et
    - chaque microstructure étant réalisée sous la forme d'une grille à sous-longueurs d'onde (20) qui diffracte avec réflexion une première partie du rayonnement visible qui est incident à travers l'ouverture (24) du microréflecteur (22) depuis l'espace semi-infini, caractérisé en ce que
    chacune des grilles à sous-longueurs d'onde (20) diffracte la première partie dans un zérotième ordre de réflexion par diffraction.
  13. Procédé selon la revendication 12, caractérisé en ce que la grille à sous-longueurs d'onde (20) est réalisée sous la forme d'une grille à sous-longueurs d'onde semi-transparente qui diffracte avec transmission une deuxième partie du rayonnement visible qui est incident à travers l'ouverture (24) du microréflecteur (22) depuis l'espace semi-infini, chacune des grilles à sous-longueurs d'onde (20) diffractant la deuxième partie dans un zérotième ordre de transmission par diffraction.
  14. Procédé selon la revendication 13, caractérisé en ce que dans chaque réflecteur en grille (10), la grille à sous-longueurs d'onde (20) et le microréflecteur (22) sont accordés l'un sur l'autre de telle sorte que la grille à sous-longueurs d'onde (20) transmet le rayonnement incident à travers l'ouverture (24) du microréflecteur (22) depuis l'espace semi-infini et réfléchi par le microréflecteur (22) dans le zérotième ordre de transmission par diffraction.
  15. Procédé selon la revendication 12, caractérisé en ce que la grille à sous-longueurs d'onde (20) est réalisée sous la forme d'une grille à sous-longueurs d'onde opaque.
  16. Procédé selon l'une des revendications 12 à 15, caractérisé en ce que dans chaque réflecteur en grille (10), la grille à sous-longueurs d'onde (20) et le microréflecteur (22) sont accordés l'un sur l'autre de telle sorte que le microréflecteur (22) réfléchit au moins partiellement en retour dans l'espace semi-infini sous la forme d'une rétroréflexion le rayonnement diffracté par la grille à sous-longueurs d'onde (20) dans le zérotième ordre de réflexion par diffraction.
  17. Procédé selon l'une des revendications 12 à 16, caractérisé en ce que les microréflecteurs (22) sont respectivement réalisés sous la forme de miroirs creux ou de rainures munis d'un fond plat (16), la grille à sous-longueurs d'onde (20) étant disposée sur le fond plat (16), les microréflecteurs (22) étant de préférence configurés pour posséder une paroi latérale (18) à côté du fond (16), laquelle présente une configuration de section transversale de forme parabolique, droite, elliptique ou une forme mélangée de celles-ci.
  18. Procédé selon l'une des revendications 12 à 17, caractérisé en ce que les microréflecteurs (22) sont asymétriques en section transversale et sont configurés avec un fond (16) et au moins une paroi latérale (18), une première partie (26) de la paroi latérale (18) étant notamment droite et une deuxième partie (28) de la paroi latérale (18) étant concave, notamment configurées de forme parabolique ou elliptique, notamment en ce que la première partie (26) de la paroi latérale (18) est configurée perpendiculairement au fond (16).
  19. Procédé selon l'une des revendications 12 à 18, caractérisé en ce que chaque grille à sous-longueurs d'onde (20) est configurée avec une période de grille entre 100 nm et 500 nm, notamment entre 240 nm et 420 nm.
  20. Procédé selon l'une des revendications 12 à 19, caractérisé en ce que les microréflecteurs (22) et les grilles à sous-longueurs d'onde (20) sont revêtus au niveau de leur côté faisant face à l'espace semi-infini d'au moins une couche métallique, de préférence avec de l'Al, de l'Ag, de l'Au, du Cu, du Cr ou d'un alliage contenant ces métaux.
  21. Procédé selon l'une des revendications 12 à 20, caractérisé en ce que l'ouverture (24) possède un diamètre (a) et le microréflecteur (22) possède entre l'ouverture (24) et le fond (16) une profondeur (t), au moins l'une des propriétés suivantes des réflecteurs en grille (10) variant à l'intérieur d'un modèle afin de générer l'image : position des grilles à sous-longueurs d'onde (20) par rapport au microréflecteur (22) respectivement associé, diamètre (a) de l'ouverture (24), profondeur (t) du microréflecteur (22), disposition du microréflecteur (22), forme du microréflecteur (22) et/ou période de grille de la grille à sous-longueurs d'onde (20), la propriété des réflecteurs en grille (10) à l'intérieur du modèle variant de préférence en continu de telle sorte que l'image est générée au moyen d'un effet de moiré.
EP16002760.3A 2015-12-23 2016-12-22 Élément de sécurité pour papiers de sécurité, documents de valeur ou analogues et procédé de fabrication d'un élément de sécurité Active EP3184319B1 (fr)

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Publication number Priority date Publication date Assignee Title
DE69636991T2 (de) 1995-11-28 2007-12-06 Ovd Kinegram Ag Optischer Informationsträger
US6819775B2 (en) 1996-07-05 2004-11-16 ECOLE POLYTECHNIQUE FéDéRALE DE LAUSANNE Authentication of documents and valuable articles by using moire intensity profiles
DE10150293B4 (de) 2001-10-12 2005-05-12 Ovd Kinegram Ag Sicherheitselement
US7221512B2 (en) 2002-01-24 2007-05-22 Nanoventions, Inc. Light control material for displaying color information, and images
EP1747099B2 (fr) 2004-04-30 2017-09-20 De La Rue International Limited Reseaux de microlentilles et de micro-images sur des substrats de securite transparents
ES2434443T3 (es) 2005-05-18 2013-12-16 Visual Physics, Llc Sistema de presentación de imágenes y de seguridad micro-óptico
DE102006005000B4 (de) 2006-02-01 2016-05-04 Ovd Kinegram Ag Mehrschichtkörper mit Mikrolinsen-Anordnung
DE102009022612A1 (de) 2009-05-26 2010-12-02 Giesecke & Devrient Gmbh Sicherheitselement, Sicherheitssystem und Herstellungsverfahren dafür
DE102009035361A1 (de) 2009-07-30 2011-02-03 Giesecke & Devrient Gmbh Sicherheitselement für einen zu schützenden Gegenstand sowie zu schützender Gegenstand mit einem solchen Sicherheitselement
DE102009040975A1 (de) 2009-09-11 2011-03-24 Ovd Kinegram Ag Mehrschichtkörper
DE102009056933A1 (de) * 2009-12-04 2011-06-09 Giesecke & Devrient Gmbh Sicherheitselement mit Farbfilter, Wertdokument mit so einem solchen Sicherheitselement sowie Herstellungsverfahren eines solchen Sicherheitselementes
DE102010019766A1 (de) 2010-05-07 2011-11-10 Giesecke & Devrient Gmbh Verfahren zur Erzeugung einer Mikrostruktur auf einem Träger
DE102011101635A1 (de) 2011-05-16 2012-11-22 Giesecke & Devrient Gmbh Zweidimensional periodisches, farbfilterndes Gitter
DE102012105571B4 (de) * 2012-06-26 2017-03-09 Ovd Kinegram Ag Dekorelement sowie Sicherheitsdokument mit einem Dekorelement
DE102012014414A1 (de) 2012-07-20 2014-01-23 Giesecke & Devrient Gmbh Sicherheitselement für Sicherheitspapiere, Wertdokumente oder dergleichen
DE102012015900A1 (de) * 2012-08-10 2014-03-06 Giesecke & Devrient Gmbh Sicherheitselement mit farbeffekterzeugendem Gitter
DE102014004941A1 (de) * 2014-04-04 2015-10-08 Giesecke & Devrient Gmbh Sicherheitselement für Sicherheitspapiere, Wertdokumente oder dergleichen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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