JP2016530118A - Security structure with diffractive optical elements - Google Patents

Abstract

The present invention comprises at least one non-opaque microzone (30) having a cross-sectional area of 1,000,000 μm 2 or less and at least one diffractive optical element (40) at least partially in the non-opaque microzone (30). Said at least one diffractive optical element (40) for generating at least one interference pattern (66) in a view plane (62) separated from a vertically adjacent diffractive optical element (40) Regarding (1). [Selection] Figure 1

Description

  The present invention relates to a security structure and a secure article, in particular a document, comprising the structure.

  The use of multiple diffractive optical elements (DOEs) as security elements is known for generating an interference pattern starting from a light source. These elements can be formed for the purpose of being illuminated by monochromatic or polychromatic light to produce an interference pattern by diffraction and transmission as it passes through the element towards the imaging plane. In some cases, this imaging plane is an imaginary plane and can be realized by a real surface that is placed between the element and the light source or located behind the element as viewed from the source.

  WO 01/00418 describes a diffractive optical element formed directly on a document by laser ablation.

  Australian Patent Application No. AU20130100172 describes a security document comprising a number of apertures created by laser ablation to create a diffractive optical element and a reflective layer having a series of grooves and a liquid crystal layer on its surface.

  WO 99/37488 is a security document using a plastic material, which is viewed using a parallel polychromatic light source thanks to the presence of another window on the same document located at a distance from the element. In such a manner, a security document is described in which a diffractive optical element is placed on or in a transparent or translucent window.

  WO 2007/079549 describes the use and viewing of diffractive optical elements on security documents. These elements are formed in such a way as to record individual data, especially documents, data present elsewhere on the document, for example facial photographs or marital status in the case of identification documents.

  WO 2008/031170 manufactures a security document comprising at least one diffractive optical element and an optical structure comprising a lens or another security element having a relief structure formed by embossing And use. This application further describes the use and viewing of binary diffractive optical elements or elements having several phase levels.

  Australian Patent Application No. AU2011101567 describes the use and viewing of diffractive optical elements on security documents that are sensitive to at least three different wavelengths. These diffractive optical elements are recorded using three different lengths, and the interference pattern is reproduced by illuminating at the appropriate wavelength.

  There is a need to be able to use a diffractive optical element with various types of substrates without the need for the entire document to be present when the diffractive optical element is manufactured.

  There is also a need to further strengthen the security structure and secure articles that integrate the structure, in particular to make counterfeiting more difficult.

  The present invention aims to meet all or part of these needs.

One subject of the present invention, according to a first of its aspects,
At least one non-opaque microregion having a cross-sectional area of 1000000 μm ² or less;
At least one diffractive optical element at least partially superimposed on the non-opaque microregion, wherein the at least one interference pattern is generated in an imaging plane located at a distance from the diffractive optical element; Security structure with two diffractive optical elements.

  The invention can be better understood by reading the following detailed description of non-limiting exemplary embodiments of the invention and examining the accompanying drawings.

It is a figure which shows typically an example of the secure document according to this invention. It is sectional drawing along II-II of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. It is a figure which shows typically another example of the secure document according to this invention. It is sectional drawing along VIII-VIII of FIG. It is a figure which shows typically another example of the secure document according to this invention. It is sectional drawing in alignment with XX of FIG. It is a figure which shows typically another example of the secure document according to this invention. It is sectional drawing along XII-XII of FIG. It is a figure similar to the figure of FIG. FIG. 6 is a diagram showing another example of a security structure according to the present invention. FIG. 6 is a diagram showing another example of a security structure according to the present invention. FIG. 6 is a diagram showing another example of a security structure according to the present invention. FIG. 6 is a diagram showing another example of a security structure according to the present invention. FIG. 6 is a diagram showing another example of a security structure according to the present invention. FIG. 6 is a diagram showing another example of a security structure according to the present invention. FIG. 6 is a diagram showing another example of a security structure according to the present invention. It is sectional drawing which shows the modification of the security structure according to this invention. It is sectional drawing which shows the modification of the security structure according to this invention. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 3 is a view similar to FIG. 2 of a variation of the example of FIG. FIG. 6 shows another security element according to the present invention. It is a figure which shows the modification of a non-opaque micro area | region. It is a figure which shows the modification of a non-opaque micro area | region. It is a figure which shows the viewing of an interference pattern typically. It is a figure which shows the viewing of an interference pattern typically.

  In these figures, which are schematic, the actual relative proportions of the various components are not necessarily followed for clarity of the drawings. Some layers may be represented as unity for the sake of brevity, while in reality they may be composed of several sub-layers. In addition, certain layers may be bonded using an adhesive layer disposed between the layers, which is not always shown in the drawings. Finally, in the presence of juxtaposed opaque and non-opaque regions, this presence is simply shown schematically by only two regions arranged side by side, but in reality these various regions are mostly In some cases, it is understood that more than two, in which case the placement can be complex, for example to define text or raster images. In the figure, the diffractive optical element is shown very simply and schematically. The potential surface relief that can be generated by embossing is not specifically shown. The absence of a surface relief does not preclude the possibility that a surface relief exists.

The non-opaque micro-region word “non-opaque micro-region” is a region that is sufficiently transparent to light to allow an interference pattern to be seen by the light that has passed through this region, and is less than 1000000 μm ² , or preferably 200000Myuemu ² or less, or more preferably in the range of 10μm ² ~200000μm ^2, or more desirably refers to a region having a cross section having a surface area in the range of 5000μm ^{2 ~200000μm 2,.} Preferably, the non-opaque microregions have a cross-sectional area that is large enough to observe the DOE in transmitted light and small enough so that it is substantially invisible in reflection. Thus, non-opaque microregions have a limited extent and are bounded by an opaque periphery. The non-opaque micro-regions are translucent and may in particular scatter part of the light that has passed through the region, or may be transparent and not scatter the light that has passed through the region. Preferably, the non-opaque microregion is transparent.

  It should be understood that the term “opaque periphery” means a higher optical density at the periphery, or an optical density equal to 1 or desirably 1.5.

  Non-opaque microregions offer the advantage that they are easily detectable only under certain viewing conditions, and therefore, if these viewing conditions are not met, non-opaque microregions are not easily visible by the naked eye . Thus, the use of non-opaque microregions allows the diffractive optical element to be more easily hidden and makes counterfeiting more difficult to achieve.

  Non-opaque microregions can have a circular cross-section, or a non-circular cross-section, in particular a polygon, in particular a regular or non-regular polygon, or an oval, in particular an elliptical cross-section.

  Non-opaque microregions may be formed in a layer of fibrous material or a layer of non-fibrous material that extends along the entire circumference of the non-opaque microregion.

  The non-opaque microregions can be microperforations of a layer of substantially opaque material, at least partially, preferably completely filled with a transparent material, in particular a transparent material comprising a protective adhesive material. By entering into the microperforations, this transparent material allows the substantially opaque layer of material and the layer carrying the diffractive optical element to be tightly bonded together. The at least partial filling of the microperforations allows the microperforations to be protected from the external environment, in particular dust.

  For example, a non-opaque microregion or each non-opaque microregion may be defined by the absence of material within a layer of substantially opaque material, particularly when the opaque material is, for example, a fibrous substrate. It may be defined by microperforations that penetrate the opaque material, or when the opaque material is a metal, it may be defined by demetallization.

  Where microperforations are present, the microperforations are preferably formed by a laser. As a variant, the microperforations are formed by microneedles or water jets.

  When the non-opaque microregion consists of microperforations, the axis of the microperforations is preferably oriented substantially perpendicular to the surface of the layer in which the microperforations are formed. This axis can alternatively form a normal and angle to the surface of the layer being traversed by the microperforations.

  Non-opaque microregions, when defined by microperforations, can have a constant cross-sectional area or a non-constant cross-sectional area throughout the thickness of the layer being traversed by the microperforations.

  Furthermore, the boundaries of the non-opaque microregions can be defined by printing a transparent film of opaque material, in particular a plastic material, for example the same film on which the diffractive optical element is formed.

  The same layer of the structure according to the invention may have a plurality of non-opaque microregions each at least partially superimposed on the same diffractive optical element.

  Each of the one or more non-opaque microregions may form a pattern that is found within at least a portion of an interference pattern generated by the diffractive optical element.

  For example, non-opaque microregions have contours that are located within the interference pattern, eg, the same geometric shape.

  Some non-opaque micro-regions are generally patterns found within at least a portion of the interference pattern, such as images of the same celebrity, place, monument or object, or the same text, such as the value or bank name of a banknote, Can be defined. The pattern facilitates authentication by an observer by comparing the pattern with an interference pattern. This arrangement enhances the security of the document because forgery requires that the pattern be reproduced both within the micro-region of the security structure and within the interference pattern.

  For non-opaque microregions formed by microperforations, the thickness of the layer traversed by the microperforations can range from 10 to 1000000 μm.

The number of non-opaque micro-region is preferably 1 to 1500 per 1 cm ^2, preferably 10 to 500 per 1 cm ^2, and even more preferably 10 to 300 per 1 cm ^2, the range of.

Diffractive optical element The diffractive optical element that generates the interference pattern in an imaging plane located at a distance from the diffractive optical element is preferably of the digital type. In that case, the fabrication of the diffractive optical element is applied as a function of complex data reconstructed in the imaging plane to form a two-dimensional interference pattern, as described in WO 2008/031170. Based on die patterning. Thus, when illuminated by a collimated light source, the diffractive optical element generates an interference pattern that produces an image in this imaging plane, which can be viewed on or out of the surface located in this plane. Can be seen in the beginning transmission.

  The mathematical transformation between the element and the imaging plane can be related to a fast Fourier transform (FFT). Therefore, complex data including phase information and amplitude information must be physically encoded within the fine structure of this element. The relief imparted to the microstructure can be calculated by performing an inverse FFT transform of the desired pattern in the imaging plane.

  Diffractive optical elements are sometimes classified as computer generated holograms, and are different from other types of holograms, such as rainbow, Fresnel or 3D reflection holograms.

  Preferably, the diffractive optical element is an embossed structure.

  Preferably, the interference pattern generated by the diffractive optical element is at least partially, or preferably entirely, on the security structure or in particular in the form of printed features, watermarks ( watermark) and / or articles, especially documents, incorporated in the form of micro-perforations or patterns generated by metallization or demetallization. In the case of microperforations, one of the microperforations can define a non-opaque microregion.

  For example, a diffractive optical element produces an image of a celebrity, and there is a watermark that reproduces the same celebrity on a fibrous substrate formed with microperforations that define non-opaque microregions.

  Non-opaque micro-regions can also belong to security elements that reproduce all or part of the interference pattern. For example, non-opaque microregions are formed by demetalization of metalized security threads, and celebrity images generated by interference patterns are formed by demetalization on threads, diffraction It is found on the thread that is superimposed or not superimposed with the optical element.

  Preferably, the diffractive optical element is smaller than the non-opaque microregion, particularly in all directions of its plane. As a variant, the diffractive optical element can be larger than the non-opaque microregion in at least one direction of its plane.

  The diffractive optical element is preferably formed on a thermoplastic film, preferably transparent, having a thickness of 50 μm or less, in particular by embossing of this film. The thermoplastic film can be laminated at least in part with a layer carrying non-opaque microregions or a layer through which non-opaque microregions are formed. As a variant, the thermoplastic film comprising the diffractive optical element is fixed to the layer carrying the non-opaque microregions by means of an adhesive, preferably by a protective structure comprising an adhesive material. As previously described, this adhesive structure is in the liquid state via at least one microperforation, in particular at least one non-opaque, between the thermoplastic film and the layer carrying the non-opaque microregions. It can be introduced via at least one microperforation forming a microregion.

  The presence of the thermoplastic film allows the diffractive optical element to be formed independently of the rest of the secure article and thus facilitates the manufacture of the diffractive optical element.

  The thermoplastic film may be laminated or bonded with a security element having at least one transparent region, in particular a non-opaque microregion, at least partially superimposed with a diffractive optical element, and in particular with a security thread or foil. . This security element may comprise a security pattern, in particular in the form of printed features, in the form of micro-perforations or in the form of metallization or demetallization. As pointed out above, this pattern may correspond at least in part to the interference pattern generated by the diffractive optical element.

  The diffractive optical element can be recorded on a thermoplastic film by a “roll-to-roll” process.

  The diffractive optical element can be seen under polychromatic or monochromatic light.

  The diffractive optical element may be associated with an interference, iridescent or absorption optical filter placed in the path of light that reaches or exits the diffractive optical element. This filter may belong to a security structure or article and may therefore constitute an additional security element.

Security structure The security structure may take the form of elements integrated into the fiber substrate during the manufacture of the fiber substrate or transferred to the surface of the fiber substrate.

  The security structure may take the form of a patch, security thread, foil or film.

  The security structure may have two opposite sides of the security structure exposed to the external environment, or only one of those faces may be exposed to the external environment, or both sides of the security structure may be fully May be coated with one or more layers that are not opaque, such as protective films or varnishes.

  The security structure may consist of a single element during the integration of the security structure in or on the remaining part of the article, in particular the document, or is joined by the remaining part of the article, in particular the document Can consist of several sub-elements, for example transferred to different sides of the document substrate. These sub-elements may or may not contact each other. For example, the first sub-element may carry a diffractive optical element, the second sub-element may carry an associated non-opaque microregion, and these two sub-elements may be They may be separated by at least one substrate layer or may be directly bonded to each other.

  Preferably, a protective adhesive structure in which the security structure is arranged between a first sub-element carrying a diffractive optical element, in particular between a diffractive optical element and a second sub-element carrying a non-opaque microregion, Or an adhesive structure associated with the protective structure.

  The term “protective adhesive structure or protective structure” refers to one or more designed to mechanically and / or optically protect a diffractive optical element, particularly when the diffractive optical element is an embossed structure. It is understood to mean a layer.

  The protective adhesive structure preferably comprises a layer of a mixture of HRI (high refractive index) material and adhesive material disposed on the diffractive optical element.

  As a variant, the first subelement comprises a layer of HRI material, preferably a layer of HRI material deposited on the diffractive optical element by vacuum evaporation, preferably on which a layer of adhesive material is arranged. This layer of adhesive material is preferably disposed between the layer of HRI material and the second subelement carrying the non-opaque microregions. This superposition of the layer of HRI material and the layer of adhesive material forms a protective adhesive structure. This adhesive layer provides mechanical protection for the diffractive optical element.

  The HRI material allows the diffractive optical element to be protected from attenuation or cancellation of the optical effects of the diffractive optical element that may be caused by the presence of the adhesive material.

  As another variation, the protective structure associated with the adhesive structure includes a mixture of HRI (high refractive index) material and binder disposed on the diffractive optical element, the adhesive structure preferably comprising: Arranged on the protective structure, in particular between the second sub-element carrying the non-opaque microregion and the protective structure.

  As another variant, the first sub-element comprises a layer of HRI material arranged on the diffractive optical structure, in particular a layer of HRI material deposited by vacuum evaporation, on which a layer comprising a binder The overlay of the layer of HRI material and the layer containing the binder forms a protective structure associated with the adhesive structure. The adhesive structure is preferably arranged on the protective structure, in particular between the protective structure and the second sub-element carrying the non-opaque microregion.

  Preferably, the binding agent is secured, for example by the presence of specific markers or luminescent compounds. The layer of HRI material provides optical protection to the diffractive optical element, and the layer of binder provides mechanical protection to the diffractive optical element.

  The HRI material allows the diffractive optical element to be protected from attenuation or cancellation of the optical effects of the diffractive optical element, which can be caused by the presence of the adhesive material and / or the presence of the layer containing the binder.

"HRI material" is understood to mean a material having a high refractive index, preferably a high refractive index of 1.7 or higher. The HRI material is preferably zinc sulfide (ZnS), zinc oxide (ZnO), zirconium oxide (ZrO ₂ ), titanium dioxide (TiO ₂ ), carbon (C), indium oxide (In ₂ O ₃ ), indium tin oxide ( ITO), tantalum pentoxide (Ta ₂ O ₅ ), cerium oxide (CeO ₂ ), yttrium oxide (Y ₂ O ₃ ), europium oxide (Eu ₂ O ₃ ), iron oxide, hafnium nitride (HfN), hafnium carbide ( HfC), hafnium oxide (HfO ₂ ), lanthanum oxide (La ₂ O ₃ ), magnesium oxide (MgO), neodymium oxide (Nd ₂ O ₃ ), praseodymium oxide (Pr ₆ O ₁₁ ), samarium oxide (Sm ₂ O ₃₎ ), antimony trioxide _{(Sb 2 O} 3), silicon carbide (SiC), silicon nitride _{(Si z N} u), monoxide Ke Containing (SiO), selenium trioxide _{(Se 2 O} 3), tin oxide _(SnO 2), three tungsten oxide _(WO 3), is selected from among these combinations and other compounds of the same type.

  The protective adhesive structure, or the adhesive structure associated with the protective structure, is introduced via one or more microperforations of the second subelement, in particular at least one microperforation that defines a non-opaque microregion. sell. The protective adhesive structure, or the adhesive structure associated with the protective structure, can fill one or more microperforations, partially or preferably completely.

  As a variant, the diffractive optical element is arranged on the first side of the first sub-element, the second side of the sub-element not having any diffractive optical element and the adhesive structure is the second sub-element And the second side of the first sub-element. Thus, the adhesive structure is not in contact with the diffractive optical element.

  The security structure may comprise a plurality of the above diffractive optical elements, each of which can generate an interference pattern in an imaging plane located at a distance from the diffractive optical element.

  These diffractive optical elements can produce different or identical interference patterns that are complementary or not complementary.

  Preferably, a protective adhesive structure or protective structure is applied to all diffractive optical elements.

  The security structure may comprise a plurality of non-opaque microregions, each of which can be at least partially overlaid on at least one corresponding respective diffractive optical element.

  Preferably, a plurality of non-opaque microregions are overlaid on the same diffractive optical element.

  The one or more non-opaque microregions may visually define a pattern that is at least partially found within the interference pattern generated by the at least one diffractive optical element. For example, some non-opaque microregions are arranged according to an arrangement that reproduces one or more alphanumeric characters, and the interference pattern produces these same alphanumeric images in the imaging plane. This pattern facilitates authentication by comparing this pattern with the pattern of interference. This arrangement further increases the potential for potential counterfeiters who will have to reproduce the pattern both within the micro area of the security structure and within the interference pattern.

  The security structure may comprise at least one absorption or interference filter, in particular a colored filter, at least partially superimposed on non-opaque microregions.

  The security structure may comprise at least two non-opaque microregions, each formed by a microperforation having an axis that forms an angle with the normal to the surface of the security structure, and the angles may be different. Each of the at least two diffractive optical elements can be at least partially overlaid on a corresponding non-opaque microregion. This arrangement allows the ability to see one or the other of the generated interference patterns by directing the light beam in different orientations, for example by alternating these two interference patterns. Allows the ability to produce animation by observing.

Secure article, in particular document Another subject of the invention is a secure article, in particular a document, provided with a security structure according to the invention.

  The secure document may comprise a substrate having at least one window, in particular a fibrous substrate, the window being at least partly on both the diffractive optical element and the non-opaque microregion. Can be overlaid. The security structure can be transferred onto or integrated into the substrate.

  The secure article may have at least a second non-opaque microregion that is at least partially overlaid on both the diffractive optical element and the first non-opaque microregion. The non-opaque microregions or each non-opaque microregion can be defined by the absence of material, in particular microperforations. Each microperforation can be formed in the fibrous layer. Observation is performed through these two non-opaque microregions.

  The secure article may comprise a substrate, in particular a fibrous substrate, comprising microperforations that define non-opaque microregions, and the diffractive optical element is transferred onto or integrated into the substrate Can exist on a designated security element. In this case, the security structure comprises a security element and a base.

  The secure article can comprise a security element having at least one non-opaque microregion overlying a diffractive optical element. The diffractive optical element may be formed on a thermoplastic film that is bonded to the security element, for example by lamination, while the security element is already in place or not on the document.

  The secure article includes a passport, an identification card, an access card, a driver's license, an interactive playing card or a collector's card, a payment means, in particular a payment card, a banknote, a tax stamp, a vignette, a coupon, a travel card, a loyalty card, It can be a service card or membership card, token, or casino chip.

  The secure article preferably carries at least one security element or pattern that is at least partially identical or similar to the interference pattern.

  “Similar” means that by applying a transformation, especially re-scaling, the two patterns can be the same, the two patterns can be the same shape, the two patterns are It is understood that this means that the same information, in particular alphanumeric information, can be presented. In this case, the typography can be different. These two patterns include, for example, the same textual information, in particular marital status, banknote currency, place name, date, or the same visual information, in particular photos or figures.

Authentication method Another subject of the present invention is a method for authenticating a security structure or a secure article, in particular a document, according to the invention, comprising:
Illuminating the diffractive optical element with a light source;
Verifying the presence of an interference pattern in an imaging plane located at a distance from the diffractive optical element, particularly through non-opaque microregions.

  The light is preferably parallel light.

  Preferably, when the diffractive optical element is illuminated, light traverses the non-opaque microregions before encountering the diffractive optical element and generating an interference pattern.

  The light source may be a multicolor light source and the imaging plane may be a virtual plane and may be disposed between the light source and the security structure. This polychromatic light can be white light. This interference pattern is observed through a non-opaque minute region that acts as a viewfinder.

  The method may include placing at least one filter, such as a colored filter or interference filter, between the light beam and the security structure or between the imaging plane and the viewer.

  The presence of the filter is seen without hidden elements or filters, where a single wavelength is selected and, in particular, in the case of complex multi-tone patterns consisting of a superposition of simple patterns with different colors Allows difficult elements to be seen more easily.

  Alternatively, the light source may be a monochromatic light source, in particular a monochromatic light source that is coherent and / or parallel light, and the imaging plane may be a real plane and may be placed behind the security structure as viewed from the light source.

  Verification of the presence of the interference pattern can be performed by a device, in particular a mobile phone, equipped with a camera whose focusing is located in the imaging plane. The use of a device other than the eye allows any risk to the eye associated with high intensity light, especially in the case of laser use, to be avoided.

  The method converts an interference pattern generated by a diffractive optical element into a pattern present on an article, in particular a pattern defined by watermarks, printed features, metallization or demetallization, or microperforations, or For example, it may include a step of comparing with a pattern that is not directly observable recorded on an RFID chip or on a server. Access to the pattern recorded on the RFID chip or on the server can be obtained by a link present on the document.

  The method may include verifying that the data from the interference pattern actually corresponds to the data carried by other places in the document.

  In the case of observation by an electronic device of an interference pattern generated by a diffractive optical element, the electronic device is configured to automatically analyze the observed image in order to verify the authentication of an article, particularly a document. For example, it may be configured to compare the image with reference information, or it may be configured to decode the image to extract information compared with the reference information from the image.

  The electronic device may be configured to analyze the observed interference pattern and may further be configured to access a database that allows the authentication of an article, particularly a document, to be verified.

  Articles, particularly documents, may carry information that allows reference data to be accessed via a remote server. This data then allows the observed image to be verified as originating from a genuine diffractive optical element.

  This information is stored on an RFID chip present on the document and can be read by a device used for the purpose of observing the interference pattern, for example using NFC technology.

  The security article 10 shown in FIGS. 1 and 2, for example a document, for example a banknote, comprises a diffractive optical element 40 at least partially superimposed on a non-opaque microregion 30, according to the invention. 2 is provided.

  The article 10 comprises a substrate 11, in particular a paper substrate 11, having a window 15 that provides visual access to the diffractive optical element 40.

  In the example being considered, the non-opaque microregion 30 is formed by a microperforation having an axis X formed through the substrate 18 of the document 10, in particular the paper substrate 18, joined with the substrate 11. Yes.

  The diffractive optical element is formed on a film 43 of transparent plastic material, the film 43 having a non-opaque region 23 at least partially superimposed on the diffractive optical element 40 and on the microperforations 30. Coupled with element 20.

  The thermoplastic film 43 can be made of polyethylene terephthalate (PET).

  The diffractive optical element 40 generates an interference pattern in an imaging plane located at a distance.

  These at least partial alignments of the various openings and transparent regions define a non-opaque region A that extends from one side of the secure document 1 to the other.

  With reference to FIGS. 29 and 30, an example of a method according to the invention for viewing the security structure 2 will be described.

  Viewing the interference pattern of the security structure 2 is accomplished in a plane 62 located at a distance from the diffractive optical element 40 by illuminating the non-opaque microregion 30 with a light source 60.

  The security structure 2 is preferably in such a way that the plane of the security structure 2 is oriented perpendicular to the incident light originating from the light source 60 and the non-opaque microregions 30 are preferably arranged on the light source 60 side. Be placed.

  The non-opaque microregion 30 in particular allows the diffractive optical element 40 to be targeted by the incident beam.

  The light source 60 is preferably a parallel light source.

  As shown in FIG. 29, the light source 60 can be a monochromatic light source, particularly a laser. In that case, the imaging plane 62 is a real plane and is arranged downstream of the security structure 2 when viewed from the light source 60. Viewing the interference pattern 66 can be accomplished with the help of a portable device, in particular a mobile phone placed in the imaging plane 62 set to a photographic mode or a video mode. The interference pattern 66 is seen through the non-opaque microregion 30.

  As shown in FIG. 30, the light source 60 can be a multicolor source. In that case, the image forming plane 62 is a virtual plane, and is disposed upstream of the security structure 2 when viewed from the light source 60. The interference pattern 66 can be seen by observing the light source 60 through the non-opaque microregion 30.

  Authentication of security structure 2 may require the use of a filter 68 located upstream or downstream of security structure 2. This filter can allow visible wavelengths to be filtered.

  The security structure 2 converts the interference pattern 66 generated by the diffractive optical element 40 into one or more additional pieces of information that are present on the security structure 2 or on the related article 10, for example, watermarks, printed features, Authentication can be achieved by comparison with a comparison pattern defined by metallization or demetallization, or microperforations. Non-opaque microregions 30, particularly non-opaque microregions 30 that are demetalized or micro-perforated, may at least partially constitute this comparative pattern.

  The present invention is not limited to a specific secure article, and the secure article may be an identification document or card other than a valuable document. Accordingly, the substrates 11 and 18 in the example of FIGS. 1 and 2 can be non-fibrous.

  The diffractive optical element 40 can be formed on the thermoplastic film 43 according to one of the previously described methods. The thickness e of the diffractive optical element 40 is preferably 50 μm or less, or desirably 25 μm or less.

  The diffractive optical element 40 may have a cross-sectional area that is larger than the cross-sectional area of the non-opaque microregion 30, as shown in FIG.

Non opaque minute region 30 is preferably less than 1,000,000 ^2, or, preferably 200000Myuemu ² or less, or, more preferably in the range of 10μm ² ~200000μm ^2, or, more preferably in the range of 5000μm ² ~200000μm ^2, the cross-sectional area of the S.

  Non-opaque microregions 30 can be configured in various ways when taking the form of microperforations.

  As shown in FIG. 14, the non-opaque microregion 30 may have a variable cross-sectional area, particularly a variable cross-sectional area that gradually narrows in the direction of the diffractive optical element 40.

  FIG. 15 shows a non-opaque microregion 30 whose axis X is formed by a microperforation that forms a non-zero angle α with the normal to the surface of the security structure 2. The angle α can be in the range of −45 ° to 45 °.

As shown in FIG. 16, the security structure 2 may comprise at least two non-opaque microregions 30 ₁ and 30 ₂ open on the same surface S ₁₂ , in which case each non-opaque micro-region Regions 30 ₁ and 30 ₂ can be overlaid on respective corresponding diffractive optical elements 40 ₁ or 40 ₂ . By changing the viewing angle, this configuration allows the diffractive optical element that it is desired to observe to be selected. If desired, the animation can be observed by looking at these two interference patterns alternately.

  Non-opaque microregions 30 may be formed in a manner different from that of microperforations that penetrate the opaque layer.

  As shown in FIG. 17, the non-opaque microregions 30 can be filled with a colorless or non-colorless transparent non-opaque material.

  As shown in FIG. 18, non-opaque microregions 30 can be delimited by printed features 35. The layer 38 with the printed features formed thereon can be a transparent film carrying the diffractive optical element 40 on the opposite side of the printed features.

  As a modification, the non-opaque micro-region 30 can be formed by demetalization of the metal layer 37 as shown in FIG.

  The security structure 2 may comprise an optical filter placed in the path of light reaching or exiting the diffractive optical element.

  FIG. 20 shows a security structure 2 comprising an absorption or interference optical filter 80, in particular a colored filter 80, overlaid on a non-opaque microregion 30.

  The filter 80 can be arranged upstream or downstream of the diffractive optical element 40. Filter 80 allows one or more light wavelengths to be selected when an interference pattern is seen. This filter allows the interference pattern to be personalized by allowing selection of the display color.

As shown in FIG. 21, the security structure 2 includes a plurality of diffractive optical elements 40 ₁ ,. . . , 40 _i and corresponding axes X ₁ ,. . . , X _i and a plurality of corresponding non-opaque microregions 30 ₁ ,. . . , 30 _i . Non-opaque microregions 30 ₁ ,. . . , 30 _i correspond to the corresponding diffractive optical elements 40 ₁ ,. . . , 40 _i , respectively.

The security structure 2 comprises at least one diffractive optical element 40 ₁ ,. . . , 40 _i may comprise a security element 20 comprising one or more non-opaque areas 23 at least partially overlapped. The non-opaque region 23 includes at least two diffractive optical elements 40 ₁ ,. . . , 40 _i .

In the modification shown in FIG. 23, the security structure 2 includes a plurality of colored filters 60 ₁ ,. . . , 60 _i , in particular, the colored filters 60 ₁ ,. . . , 60 _i . A plurality of colored filters 60 ₁ ,. . . , 60 _i is at least one corresponding respective diffractive optical element 40 ₁ ,. . . , 40 _i , respectively.

  It can be seen in particular in FIG. 2 that the security structure 2 can comprise a security element 20 at least partially superimposed on the diffractive optical element 40 and on the non-opaque microregion 30. More specifically, as shown, this security element 20 can be viewed through the window 15 and can be placed between the substrate 11 and the film 43 carrying the diffractive optical element 40.

  The security element 20 is preferably at least partially opaque, for example at least partially metallized.

  The non-opaque region 23 can be formed by demetalization or perforation.

  As shown in FIG. 1, the element 20 can provide security features that can be seen through the window 15, for example, security features in the form of a pattern 50 placed outside the non-opaque region 23. The pattern 50 is formed by printing or demetalization, for example.

  As shown in FIG. 1, the pattern 50 is composed of alphanumeric characters, for example. This can be text that provides information about the bank name, country name and / or banknote value.

  The pattern 50 may be formed in the form of a raster point that reproduces the image in the transmitted light according to the teachings of WO 2006/066927, in which case one of a plurality of demetallized or perforated patterns 50 One demetalization or perforation can form a non-opaque microregion 30.

  The pattern 50 is preferably found partially or completely within the interference pattern 66 produced by the diffractive optical element 40. For example, in FIG. 1, a pattern 50 representing the value of a banknote is found within an interference pattern that also represents the value of a banknote, in which case the typography may be the same or different.

  Generally speaking, in the case of a security element 20 comprising a metallized layer, usable metals include aluminum, copper, gold, iron, silver, chromium, nickel, zinc, cadmium, bismuth, and these Names of alloys and oxides may be mentioned.

  Security element 20 may take the form of a security patch, thread or foil.

  When the security element 20 is a security thread, the width of the security element 20 may be relatively small, and may be preferably 10 mm or less.

  The window 15 may be formed by a cut-out and has a contour of any shape, for example a circle, an ellipse or a polygon as shown in FIG. 1, in particular a regular polygon or a non-regular polygon. Yes.

  There may be a single window 15 on the document, or the document may comprise several windows 15. In this case, the window 15 can be arranged on the same side or the opposite side of the document.

  The window 15 may be formed, for example, by changing the fiber accumulation on the forming web, and the non-opaque microregions 30 are formed in particular by microneedles or water jets, preferably by laser ablation. sell. Layers 11 and 18 are, for example, fibrous layers that are bonded together in the wet stage.

  Each of the two layers 11, 18 has a thickness l in the range of, for example, 10 to 1000 μm, or desirably 50 to 700 μm.

  The two layers 11, 18 can comprise natural fibers and / or synthetic fibers.

  The substrates 11 and 18 can alternatively be non-fibrous.

  More generally, the document 10 may have a multilayer structure that includes at least one fibrous layer and a layer of thermoplastic material.

  Preferably, the diffractive optical element 40 is laminated with the security element 20 before being incorporated into the secure document 1.

  As a variant, the diffractive optical element 40 is fixed to the security element 20 by adhesive bonding with heat or cold. The adhesive used is, for example, a polymer adhesive type transparent adhesive, for example NOLAX.

  As shown in FIG. 2, the assembly composed of the security element 20 and the diffractive optical element 40 may be incorporated between the two layers 11, 18 with the security element 20 on the side of the window 15. Can be arranged.

  Generally speaking, the article 10 may comprise various first, second or third level added security elements. Some of the additional security elements can be seen by the eye under sunlight or artificial light without using a specific device. These security elements include, for example, fibers or colored planchettes, threads that are printed, or wholly or partially metallized. These security elements are said to be first level elements.

  Other types of additional security elements can only be seen with the help of relatively simple devices, such as lamps that emit in the ultraviolet (UV) or infrared (IR) range. These security elements include, for example, fibers, plan sets, strips, threads or particles. These security elements may or may not be visible to the naked eye and can, for example, emit light under illumination from a wood lamp that emits a wavelength of 365 nm. These security elements are said to be second level elements.

  Other additional types of security elements require more sophisticated detection devices for their detection. These security elements can generate specific signals when applied, for example, to one or more external excitation sources simultaneously or without. Automatic detection of the signal allows the document to be proven authentic if desired. These security elements comprise, for example, tracers in the form of active materials, particles or fibers, which are identified when subjected to optronic, electrical, magnetic or electromagnetic excitation. Can be generated. These security elements are said to be third level elements.

  At least one of these security elements may define information found within the interference pattern generated by the diffractive optical element 40.

  As is the case in the example of FIG. 2 in particular, the diffractive optical element 40 and the layer 18 defining the non-opaque microregion 30 can be in contact with each other.

  As a variant, the diffractive optical element 40 and the layer 18 defining the non-opaque microregion 30 can be separated by one or more intermediate layers.

  For example, as shown in FIG. 3, the film 43 carrying the diffractive optical element 40 may be arranged in a manner adjacent to the substrate 11 with the window 15, and the security element 20 43 and the non-opaque microregion 30 may be placed.

  Preferably, as shown in FIG. 23, the diffractive optical element 40, in particular the diffractive optical element 40 on the side carrying the diffractive optical element 40 of the film 43, and the layer 18 comprise a protective adhesive structure 45, preferably Separated by a protective adhesive structure 45, which includes a layer of a mixture of adhesive material and HRI material. The protective adhesive structure 45 allows the film 43 carrying the diffractive optical element 40 and the layer 18 to be securely attached together. The presence of the HRI material avoids attenuation or cancellation of the optical effects of the diffractive optical element that can be caused by the superposition of the adhesive material and the diffractive optical element 40.

  The diffractive optical element 40, as a variant, carries a layer 47 of HRI material which itself carries a layer of adhesive material, in particular a layer 47 of HRI material deposited on the diffractive optical element 40 by vacuum evaporation. sell. In this case, the layer 47 allows the diffractive optical element 40 to be protected from attenuation or cancellation of the optical effects of the diffractive optical element 40 due to the presence of this adhesive structure. Mechanical protection of the adhesive structure is provided by a layer 46 of adhesive material.

  As an alternative, as shown in FIG. 24, the diffractive optical element 40, in particular the side carrying the diffractive optical element of the film 43, and the layer 18 comprise an adhesive structure 46 containing an adhesive material and an HRI material. The protective structure 47 is applied to the diffractive optical element 40, in particular the side carrying the diffractive optical element 40 of the film 43, and the adhesive structure 46 is applied to the protective structure 47 and the layer 18. Between.

  The protective structure 47 may include a binder, preferably a secured binder.

  In the variant shown in FIG. 25, the film 43 and the layer 18 are separated by an adhesive structure 46, which is located on the side of the film 43 where the diffractive optical element 40 is not present. On the diffractive optical element 40 there may be a protective structure 47 comprising HRI material, in particular the protective structure 47 may completely cover the diffractive optical element 40. This protective structure 47 in particular allows the diffractive optical element 40 to be mechanically protected during the coupling of the security structure 2 and the article 10 while maintaining the optical properties.

  In the variation shown in FIG. 26, the film 43 and the layer 18 are separated by a protective structure 47 comprising a layer 47a of HRI material, a layer 47b of binder and an adhesive structure 46 comprising adhesive material. ing. The layer 47a of HRI material preferably covers at least partially the diffractive optical element 40, and the layer 47b of binder preferably covers the layer 47a of HRI material.

  Preferably, the binder is secured by one or more substances that are luminescent or absorbing, especially under excitation by UV light, visible light and / or IR light. Preferably, the luminescent or absorbing material is non-scattering and the binder layer 47b is transparent. These luminescent or absorbing materials are preferably nanometer sized particles.

  Preferably, layers 47a, 47b and 46 are transparent so as not to interfere with the optical effects produced by the diffractive optical element.

  The deposition of the protective structure 47 may be carried out by printing on the diffractive optical element 40, in other words as described in French Patent Application No. 2961319, in other words, The cavity is filled with HRI material.

Enclosure 47 or protective adhesive construction 45, a metal oxide, for example TiO _2, nanoparticles, in particular, 1 to 100 nm, or preferably 5 to 25 nm, nanoparticles have a diameter in the range of, and / or transparent varnishes And / or reticulatable organic binders and / or pigment dispersants.

  The thickness of the protective adhesive structure 45 is preferably in the range of 1-10 microns, or desirably 2-5 microns.

  Preferably, an adhesive structure 46 or a protective adhesive structure 45 is introduced between the diffractive optical element 40 and / or the film 43 carrying the diffractive optical element 40 and the layer 18 via micro-perforations. Preferably, as described in German Offenlegungsschrift 10 2011004935, in order to protect the microperforations from the outside environment, in particular dust, a layer 46 or 45 is provided. Is introduced to fill the microperforations.

  As shown in FIG. 4, the security element 20 may be placed in the window 15 and the film 43 may still extend between the two layers 11 and 18.

  The diffractive optical element 40 can be formed within a film 43 that extends continuously around the diffractive optical element 40. As a variant, the film 43 used to form the diffractive optical element 40 does not spread beyond the diffractive optical element 40 as shown in FIG.

  As shown in FIG. 6, the film 43 can be placed in the window 15. The same may be true for the security element 20 if present.

  As shown in FIGS. 7 and 8, the security structure 2 includes a diffractive optical element 40 and a security element 20 having a non-opaque microregion 30 at least partially superimposed on the diffractive optical element 40. Can be prepared.

  The first layer 11 may have a window 15 and the second layer 18 may have a non-opaque region 32. The window 15 and the non-opaque area 32 may or may not have the same shape and size, and form a transparent area A on the secure document 1 and in the secure document 1. The window 15 and the non-opaque region 32 can be at least partially overlapped with the diffractive optical element 40 and the non-opaque micro-region 30. The security structure 2 may have substantially the same shape as the window 15 and can be disposed in the window 15.

  The secure document 1 shown in FIG. 9 comprises two substrates 11, 18 formed by first and second layers 11, 18, where the first and second layers 11, 18 are micro-perforated, respectively. 30, 16, preferably microperforations 30, 16, formed by laser ablation, during which the diffractive optical element 40 is received. The diffractive optical element 40 and the two microperforations 30, 16 are superimposed.

  The secure document 1 shown in FIG. 11 includes a first substrate 11 that forms a first layer having a window 15, and a second substrate 18 that forms a second layer having a non-opaque microregion 30. It has. The window 15 and the microperforations 30 are superimposed so that they extend from one side of the secure document 1 to the other side and the diffractive optical element 40 forms a transparent area A in the secure document. Yes.

  As shown in FIG. 12, particularly when the diffractive optical element 40 is carried by a thermoplastic film 43, the diffractive optical element 40 may be disposed between the two layers 11, 18, and the film 43 There can be direct contact with the two layers 11, 18.

  As shown in FIG. 13, the optical security element 40 may be disposed between the substrate 18 and the security element 20, which may comprise non-opaque microregions 30.

  As shown in FIG. 27, the security element 20 may comprise a pattern 50 formed by a plurality of microperforations 19, here the letter AW, in which one of these microperforations is , Non-opaque micro-regions 30, such as dots A, can be formed. The pattern AW can be reproduced on the interference pattern generated by the diffractive optical element 40.

  The non-opaque micro-region 40 can be of various shapes, particularly a circular shape as shown in FIG. 1, or any other shape, such as a triangle as shown in FIG. 28A or shown in FIG. 28B. It can be a crescent-shaped shape.

  The invention is not limited to the embodiments shown.

  The features of the embodiments shown can be combined in variants not shown.

  The expression “having one” is synonymous with “having at least one” unless the opposite is specified.

Claims (34)

At least one non-opaque microregion (30) having a cross-sectional area of 1000000 μm ² or less;
At least one diffractive optical element (40) of digital type at least partially superimposed on the non-opaque microregion (30), the imaging being located at a distance from the diffractive optical element (40) Said at least one diffractive optical element (40) generating at least one interference pattern (66) in a plane (62).   The structure of claim 1, wherein the non-opaque microregions (30) are defined by the absence of material within the substantially opaque layer of material (18; 20).   A structure according to claim 1 or 2, wherein the non-opaque microregion (30) is defined by microperforations.   The structure of claim 1 or 2, wherein the non-opaque microregion (30) is defined by demetallization.   The structure according to any one of claims 1 to 4, wherein the boundary of the non-opaque microregion (30) is defined by printing with opaque ink. The non-opaque micro-region (30), 200000Myuemu ² below, or, preferably, has a range of 10μm ² ~200000μm ^2, or, more preferably in the range of 5000μm ² ~200000μm ^2, the cross-sectional area of, claims 1 to 5 The structure according to any one of the above.   The interference pattern (66) generated by the diffractive optical element (40) is at least partially, or preferably entirely, on the security structure (2) or in particular on the security structure (2), 7. Any one of claims 1-6, found on an article (10) incorporated in the form of a printed feature, a watermark, a micro-perforation or a pattern generated by metallization or demetallization. The structure described in the paragraph.   The interference pattern (66) is at least partially, or desirably entirely, the security structure (2) or an article incorporating the security structure (2) in the form of a pattern generated by microperforations (19). A structure according to any one of the preceding claims, found on (10), wherein one of the microperforations (19) defines the non-opaque microregion (30).   The non-opaque microregions (30) forming a pattern are found on at least a portion of the interference pattern (66) and are preferably identical or similar to the interference pattern (66). Item 9. The structure according to any one of Items 1 to 8.   10. A protective adhesive structure (45) disposed between the diffractive optical element (40) and a sub-element carrying the non-opaque microregion (30). The structure described in   The structure of claim 10, wherein the protective adhesive structure (45) comprises a mixture of adhesive material and HRI material.   The protective adhesive structure (45) is formed of a layer of HRI material, preferably a layer of HRI material deposited on the diffractive optical element by vacuum evaporation, and a layer of adhesive material. The structure described in   13. A structure according to any one of claims 10 to 12, wherein the protective adhesive structure (45) fills at least one microperforation at least partially or desirably completely.   An adhesive structure (46) associated with a protective structure (47), the adhesive structure disposed between the diffractive optical element (40) and the sub-element carrying the non-opaque microregion (30) The structure according to any one of claims 1 to 9, comprising (46).   15. The structure of claim 14, wherein the protective structure (47) comprises a mixture of HRI material and binder and is applied to the diffractive optical element (40).   15. Structure according to claim 14, wherein the adhesive structure (46) is arranged between a sub-element carrying the non-opaque microregion (30) and the protective structure (47).   The protective structure (47) is formed by overlaying a layer (47a) of HRI material and a layer (47b) containing a binder, the layer (47b) containing a binder being the layer of HRI material. (47a) The structure according to any one of claims 1 to 9, which is arranged on the top.   The adhesive structure (46) comprises a diffractive optical element (40) of a second subelement carrying the non-opaque microregion (30) and a first subelement carrying the diffractive optical element (40). The structure according to any one of claims 14 to 17, wherein the structure is arranged between the side having no surface.   19. A structure according to any one of claims 14 to 18, wherein the adhesive structure fills at least one microperforation at least partially or desirably completely.   20. Structure according to any one of the preceding claims, wherein the diffractive optical element (40) is formed on a thermoplastic film (43) having a thickness of 50 [mu] m or less, preferably transparent.   21. The structure of claim 20, wherein the thermoplastic film (43) is laminated with an at least partially opaque layer (20) that defines the non-opaque microregion (30).   The thermoplastic film (43) comprises a security element (20) having at least one transparent region (23) at least partially overlapped with the diffractive optical element (40), in particular a security thread or foil, and a security element 24. The structure of claim 21, wherein the structure is laminated with security elements, particularly in the form of printed features, watermarks, micro-perforations or patterns generated by metallization or demetallization.   Comprising a plurality of said diffractive optical elements (40) and a plurality of non-opaque microregions (30), each of said plurality of non-opaque microregions (30) in particular at least one corresponding respective diffractive optics. 23. A structure according to any one of claims 1 to 22, overlaid at least partially on the element (40).   24. Structure according to any one of the preceding claims, comprising at least one optical filter (80), in particular a colored filter, at least partially superimposed on the non-opaque microregion (30).   25. A structure according to any one of the preceding claims forming a patch, foil or security thread.   26. A structure according to any one of the preceding claims, comprising an at least partially opaque fibrous layer (18) defining the non-opaque microregions.   Secure article (10) comprising a security structure (2) according to any one of the preceding claims.   Comprising a substrate (11) having at least one window (15), in particular a fibrous substrate (11), the window (15) on the diffractive optical element (40) and on the first non-illuminating element. 28. Secure article according to claim 27, which is at least partially overlaid both on the opaque microregion (30).   Comprising a substrate (11) having at least a second non-opaque microregion (16), said second non-opaque microregion (16) being above said diffractive optical element (40) and said non-opaque microregion 28. The secure article of claim 27, overlaid at least partially on both of (30).   The goods include passports, identification cards, driver's licenses, interactive playing cards or collectors cards, payment means, in particular payment cards, banknotes, coupons or vouchers, secure tags, travel cards, loyalty cards, service cards or membership cards, 30. A secure article according to any one of claims 27 to 29, which is or a specific payment instrument, for example a token or a chip, in particular a chip used in a casino.   31. A secure article according to any one of claims 27 to 30, comprising at least one security element or pattern that is at least partially identical or similar to the interference pattern (66). The security structure authentication method according to any one of claims 1 to 26, wherein:
Illuminating the diffractive optical element with a light source (60);
Verifying the presence of an interference pattern (66) in an imaging plane (62) located at a distance from the diffractive optical element (40), in particular through the non-opaque microregions.   33. The method according to claim 32, wherein the verification of the presence of an interference pattern (66) is performed by a device comprising a camera, in particular a mobile phone. The interference pattern (66) generated by the diffractive optical element (40) and the pattern (50) present on the document, in particular watermarks, printed features, metallization or demetallization, or microperforations. 34. A method according to claim 32 or 33, comprising comparing to a pattern (50) defined by.

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