HK1192359B - Method of authenticating and/or identifying a security article - Google Patents

Description

Methods for authenticating and/or identifying security items

Technical Field

The present invention relates to the field of security articles, in particular to security documents.

Background Art

Methods that rely on the persistence of retinal energy to allow for motion reconstruction are known in the prior art. For example, a psychedelic lens is known, which uses a cardboard disc perforated with slits, wherein motion is decomposed into a series of static images, and a rod supports the disc as it rotates. A zoetrope is also known, consisting of a cylinder with slits perforated in the upper half, concealed within the interior, and strips of paint decomposing the motion in the lower half. When the cylinder is rotated, the image becomes animated by peering closely through the slits into the interior. Also known is a kinescope, which operates on the principle of a zoetrope and comprises several mirrors arranged around its central axis to create the illusion of motion.

Furthermore, methods for creating motion artifacts are known, as described in US Pat. No. 5,901,484, US Pat. No. 6,286,873, and US 2005/0183300. These methods utilize the principle of motion decomposition, which allows for the reconstruction of motion "within a frame." A support carries several segmented images, for example, corresponding to the decomposition of an object in motion or an animal in motion, and a supporting transparent film is disposed on the support, which supports a network of parallel lines having a given thickness and spacing between the lines. Relative motion between the segmented images and the network of parallel lines can create a motion artifact.

The superposition of two elements formed by folding an article is also known. In particular, application WO 2006/029744 describes the superposition of two optical elements by folding a document, with different optical effects being achieved depending on the distance separating the optical elements. Furthermore, application WO 02/17242 describes the superposition of a hologram and a hidden information item by folding an article to reveal the hidden information item. Finally, application US 2006/0290136 describes the superposition of a coded image and an optical lens by folding a document to decode the image.

Furthermore, a method for identifying documents, such as banknotes, is known from application WO 2005/106808, which consists in superimposing an area of the document on an image displayed on a screen, this image originating from a decoding system sent via a network.

Furthermore, a security element is known from application WO 2006/018171, comprising an authentication feature which, in transmitted light, has a first appearance and which has a second appearance different from the first appearance when the security element is placed on a specific background, for example a liquid crystal display (LCD).

Also known is application DE 10 2007 037 576, which describes a banknote comprising an at least partially transparent window, in which a first hidden information portion is presented, and a liquid crystal display displays a second hidden information portion. The superposition of the first and second hidden information portions allows for the display of a recognizable information item. When the banknote is superimposed on a screen, the screen can also display the various hidden information portions consecutively, allowing the various recognizable information items to be viewed consecutively.

Summary of the Invention

There is a need to further enhance the security and methods for authenticating and/or identifying security articles, in order to, inter alia, increase the difficulty of counterfeiting these articles.

There is also a need to provide a method for authenticating and/or identifying a security article that is easy for the average person to perform, especially with the help of technical tools at their disposal.

Thus, according to one aspect of the invention, the invention proposes to exploit the previously described motion decomposition principle in order to be able to authenticate and/or identify a security article by observing the decomposed motion (thus giving rise to the illusion of motion).

According to one aspect of the present invention, the subject matter is therefore a method for authenticating and/or identifying a security article, in particular a security document, comprising the following steps:

- causing the first image of the security article to at least partially superimpose the second image produced by the electronic imager;

- performing a relative movement between said first image and said second image such that an item of authentication information and/or an item of identification information for the security article is observable during the relative movement between said first image and said second image.

According to the invention, it is possible to benefit from a method allowing authentication and/or identification of a security article by reconstructing an item of authentication information and/or identification information during the relative movement of said first image and said second image.

The invention may also impart an entertaining and/or eye-catching effect to the user of the security article by revealing a hidden item of information, for example by means of a motion effect or animation effect.

During the relative movement between the first and second images, a motion effect or animation effect can be observed, in particular a motion effect or animation effect of interlaced images. In particular, the verification information item and/or the identification information item can include an animation effect based on several interlaced images of the first and/or second images. Thus, the relative movement between the first and second images alone can result in the observation of animation of the individual interlaced images. In the absence of movement between the first and second images, simply superimposing the first image on the second image does not produce an animation effect, but only a static image.

The relative movement between the first image and the second image may be a physical movement between the article and the electronic imager, i.e., corresponding to an actual displacement between the security article and the electronic imager. As a variant, the relative movement between the first image and the second image may correspond to a displacement of one image relative to the other, while the security article and the electronic imager are fixed relative to each other.

Advantageously, the authentication information item and/or the identification information item may be inaccessible, in particular invisible, e.g. to the naked eye or by any other means, except during the relative movement of the first image and the second image. Thus, authentication and/or identification of the security article may only result from observation of the security article during the relative movement of the first image and the second image.

The security article may comprise a window, such as an at least partially transparent or translucent window, comprising the first image.

For example, exemplary embodiments of security windows in security articles are described in the following publications: GB1552853, which discloses windows formed, inter alia, by transparentization, laser cutting, mechanical abrasion or mechanical cutting; EP0229645, which describes forming windows on one or both sides of a double-layer paper during the wet stage; WO2004/096482, which describes forming windows by laser cutting; CA2471379, which describes forming transparent windows and association with security elements; and WO2008/006983, which describes forming transparent windows on double-layer paper.

The first image may appear in an area of reduced opacity on the security article. This area of reduced opacity may, in particular, correspond to an area of reduced thickness, an area that has become transparent, or an area comprising at least one layer of a material with reduced opacity. The opacity of the area of reduced opacity should, in particular, be sufficiently low to allow the first image to be observed in transmission. Preferably, the image is visible in both transmission and reflection.

The first image may appear on an at least partially transparent area or a translucent area of the security article.

When the electronic imager generates the second image using polarized light, the first image preferably appears on an at least partially transparent area or a semi-transparent area, in particular on an at least partially transparent window.

The second image generated by the electronic imager may be displayed on the electronic imager, for example on a screen of the electronic imager.

Alternatively, the second image may be projected by an electronic imager, for example, onto a background or onto the security article. In particular, when the second image is projected onto the background, the first image of the security article may be superimposed on the second image projected onto the background. Alternatively, the second image may be projected at least partially onto the first image of the security article.

For example, the relative movement of the first image with respect to the second image may be achieved in a plane parallel to the plane containing the second image, or vice versa.

The relative movement is preferably a translation, or indeed a rotation, or a combination of translation and rotation.

A foldable security article, one part of which is fixed relative to a second image generated by an electronic imager, and another part of which, in particular the part containing the first image, performs a rotational and/or translational movement relative to the second image generated by the electronic imager.

The security article may be foldable and the relative movement may be movement during which a portion of the security article is fixed relative to the electronic imager while another portion of the security article is moved.

A first image of the security article can be displaced relative to a second image produced by an electronic imager, with the second image being stationary. For example, the electronic imager can display or project the second image, with the second image being stationary, and a user can superimpose the first image of the security article on the second image and displace the first image relative to the second image. Thus, the relative motion between the first and second images results from movement of the security article relative to the electronic imager.

Alternatively, the relative movement between the images can be performed without relative motion between the security article and the electronic imager. By changing the display or projection, the second image produced by the electronic imager can be displaced relative to the first image of the security article, while the first image remains stationary. For example, the electronic imager can display or project a moving second image, and the user can superimpose the first image on the second image without moving the first image relative to the electronic imager.

As another variation, the display or projection of the second image is performed in a time-varying manner to produce relative motion with the first image, and, in addition, the security article and the electronic imager are in relative motion with respect to each other.

The security article and the electronic imager may or may not be in contact when the images are superimposed.

The expression "electronic imager" is intended to refer to an electronic device that can produce an image by display or projection.

For example, the electronic imager may include a screen on which the second image is displayed.

The electronic imager may comprise any known type of screen, such as a computer screen, a television screen, a mobile phone screen, the screen of an electronic book or electronic diary, the screen of a personal digital assistant, the screen of a watch face, this list not being limiting.

The electronic imager may be a projector without a screen or without a screen on which the projection is performed. The projector may project the second image onto a background or onto the security article.

For example, the electronic imager may be any known type of projector, such as a projector for slides, a video projector, a background projector, a micro-projector or a nano-projector, a miniaturized video projector, for example, integrated into a handheld device (e.g. a PDA, a mobile phone, a laptop computer), a movie projector, this list not being limiting.

The electronic imager preferably produces a pixelated image, each pixel of which is individually addressable, preferably having at least 256 grey levels or colours, with a resolution between 50 dpi ("dots per inch") and 1000 dpi.

The electronic imager may be a projector that projects visible light, infrared (IR) light, and/or ultraviolet (UV) light.

For example, the first image may be produced at least partially by means of visible inks and/or luminescent inks, such as fluorescent inks and/or phosphorescent inks.

The electronic imager may comprise an LCD (“liquid crystal display”) type screen, an LED (“light emitting diode”) type screen, an OLED (“organic light emitting diode”) type screen, a laser type screen, a plasma type screen, an electrochromic type screen, an FED (“field emission display”) type screen, an SED (“surface conduction electron emitter display”) type screen, an LCOS (“liquid crystal on silicon”) type screen or a cathode ray tube type screen.

The electronic imager preferably comprises a liquid crystal display (LCD).

The screen may have a resolution between 50 dpi and 600 dpi, preferably between 100 dpi and 300 dpi, for example equal to 160 dpi.

The first image and/or the second image may have polarization properties.

For example, the electronic imager can generate the second image by means of polarized light, in particular linearly polarized light, circularly polarized light or elliptically polarized light.The electronic imager can comprise a screen that emits polarized light or can project polarized light.

The security article may comprise a polarization filter. In particular, the first image may be generated with the aid of the polarization filter.

The first image may be generated according to at least one of the following steps:

- forming a perforation or a plurality of perforations in at least one polarizing filter to form a first image;

- locally heating at least one polarization filter, for example by means of a laser, in order to locally suppress the polarization properties of the polarization filter and thereby form the first image;

- selectively applying a diffusing material such as colloidal silica and/or adhesive tape to at least one polarizing filter, for example by printing and/or gluing, to form a first image;

- performing at least one selective etching on at least one polarization filter by a chemical reaction and/or by emitting optical radiation (in particular ultraviolet (UV) radiation and/or infrared (IR) radiation and/or laser radiation), optionally with the help of a mask, to form a first image in such a way as to locally eliminate the polarization effect of the polarization filter;

applying at least one polarizing effect to a given non-polarizing substrate, in particular to a polymer film, for example with the help of an ink comprising a polarizing compound, in particular by printing or coating said polarizing compound, to form a first image; and

Applying, in particular by printing or coating, at least one composition comprising cholesteric liquid crystals, such as the composition sold under the trade name GLUTAMATE® by the company SICPA, to a given polarizing substrate, in particular to a polymer film, in order to form a first image.

As a review, the previously described steps are carried out to form an image, which is either a positive or negative image of the first image, depending on the desired effect. In particular, a polyether-based aliphatic polyurethane (sold by LAMBERTI under the trade name PU21/S) can be topically applied to at least one polarizing filter, for example by printing.

In the last possibility mentioned above, when, during the implementation of the method according to the invention, a composition comprising cholesteric liquid crystals is located between a polarizing substrate and an electronic imager, the cholesteric liquid crystals modify the polarized light of the electronic imager, the polarized light being not blocked by the substrate, and when the polarizing substrate is positioned opaque, the areas covered with the cholesteric liquid crystals appear transparent.

On the other hand, when a polarizing substrate is positioned between the composition comprising cholesteric liquid crystals and the electronic imager, the cholesteric liquid crystals exhibit an optically variable effect when the polarizing substrate is positioned opaque. More generally, the optically variable effect of cholesteric liquid crystals is known by the term "color shift" effect, where the color of the cholesteric liquid crystals depends on the viewing angle and, in particular, on the crystals viewed against a dark (preferably black) background. The "color shift" effect of cholesteric liquid crystals can constitute an additional security measure for authenticating and/or identifying security articles.

Thus, in a particularly preferred embodiment of the method according to the invention, the first image is defined by a first polarizing material superimposed on a second polarizing material, the first material being extended in particular according to a pattern corresponding to the first image and the second material being extended in a continuous manner. The first material is preferably a print of cholesteric liquid crystal, and the second material is preferably a linearly polarizing substrate.

The expression "a pattern corresponding to the first image" is understood to mean that said pattern can form a positive or negative image of the first image.

Advantageously, when the first and second images have polarization properties, one image can only have a single orientation relative to the other, allowing one image to partially obscure the other. In other words, the first image can only have a single orientation relative to the second image, preventing the second image from being visible through the polarization region of the first image, or vice versa. In practice, the first and second images, which have polarization properties, consist of polarization regions and non-polarization regions. When the first and second images are positioned in front of a light source emitting polarized light, only a single orientation exists, and according to this single orientation, the polarization region is opaque.

In particular, for example, when the security article includes a polarizing filter, only a single orientation of the first image relative to a second image projected or displayed by the electronic imager using polarized light is present, which allows the polarizing filter to mask the polarized light of the electronic imager. The polarizing filter can be opaque, in particular black, but only in this case is a single orientation of the first image relative to the second image preferably present.

For example, a single orientation of the first and second images relative to each other as described above can authenticate and/or identify the security article according to a first security level, in particular by the presence or absence of such an orientation where one image obscures the other.

When the first and second images are arranged in said orientation, the relative movement of one image with respect to the other enables the observation of an information item for authenticating and/or identifying the security article.

According to a variant embodiment, the first image can be printed with a compound, in particular a liquid crystal, which is only visible when it is placed in front of an electronic imager that emits polarized light, in particular a liquid crystal display. Advantageously, the first image is transmissive under unpolarized lighting (e.g., natural sunlight) and is only visible under polarized lighting by means of the electronic imager, thus providing an additional security measure for the security article.

The electronic imager (eg, a screen of the electronic imager) and/or the security article may include an indicator that informs a user about how the first image and the second image are arranged relative to each other to obtain the positioning, eg, visual data.

The security article may comprise an integrated microcircuit, such as an RFID (Radio Frequency Identification) chip or an optical chip (e.g. activated by light generated by an electronic imager), which is capable of communicating with the electronic imager so that the electronic imager can generate an information item, in particular display and/or project an information item, which information item can tell about the way in which the first image and the second image are arranged relative to each other in order to obtain said positioning.

The security article may include an integrated microcircuit, such as an RFID chip or an optical chip, capable of communicating with an electronic imager so that the electronic imager can generate at least one second image, the association of which with the first image can enable the method according to the invention to be implemented. In particular, the electronic imager can generate at least one second image that is associated with the first image of the security article through communication between the electronic imager and the integrated microcircuit.

Furthermore, the electronic imager can generate at least one second image based on a photograph and/or video of the security article, in particular based on the first image of the security article or based on an identifier present on the security article (e.g., a logo or serial number). The photograph and/or video can be generated by the electronic imager, with an image capture device (e.g., a digital camera) being connected to the electronic imager via a wired or non-wired connection; and/or the photograph and/or video can be transmitted to the electronic imager, for example, from a device for storing data or via a network (e.g., the Internet).

The second image can be generated solely on the basis of a photograph and/or video of the security article, or, as a variant, the second image can be generated on the basis of a photograph and/or video of the security article and on the basis of additional information items (e.g., information items present on the security article, information items present on the photograph and/or video, information items entered by the user, or information items received from a network (such as a security server)).

For example, the electronic imager may comprise a program capable of recognizing the security article (in particular the first image) and generating, in particular displaying and/or projecting, a second image obtained from a database which, depending on the security article (in particular the first image), informs about the second image to be used.

The electronic imager may generate several second images and/or the security article may comprise several first images, and according to the method of the invention, at least one of the several second images makes it possible to observe the verification information item and/or the identification information item when at least one of the several second images is superimposed on at least one of the first images, and vice versa.

In particular, security articles may be authenticated and/or identified by various types of electronic imagers.

As a variant, a specific electronic imager can authenticate and/or identify various types of security articles, in particular security articles containing different first images.

For example, the first image may be distinguishable by its size, color, shape, or indeed by the spacing between the frame points and/or frame lines, or the thickness of the frame points and/or frame lines, in particular when the first image is a display frame and/or a combined image as defined below.

The second image may also be distinguishable by its size, colour, shape, or indeed by the spacing between the frame points and/or between the frame lines, or the thickness of the frame points and/or frame lines, in particular in the case where the second image is a display frame and/or a combined image as defined below; or indeed by the size of the pixels, the spacing between the pixels or the colour of the pixels, in particular when the second image is a frame formed by the pixels of a screen as described below.

For example, electronic imagers may be distinguished based on their brand, model, resolution, type, ie, for example, based on a computer screen, a television screen or a phone screen, or a projector screen.

The presence of several first images and/or second images enables authentication and/or identification of the security article, independently of the above-mentioned differences.

For example, the second image generated by the electronic imager may originate from a communication network with which the electronic imager communicates (e.g., a telephone network, the Internet, or an intranet), e.g., the image is downloaded; and/or, for example, the second image may be provided by the electronic imager on a data medium, such as a hard disk, a floppy disk, a USB key, a CD (Compact Disc), and/or a DVD (Digital Versatile Disc). If appropriate, the security article may include such a data medium. For example, the data medium may be an integrated microcircuit, such as an RFID or optical chip, which communicates with the electronic imager.

The security article may comprise luminescent regions, such as fluorescent regions and/or phosphorescent regions, and the electronic imager may project the second image onto the security article under ultraviolet (UV) illumination.

In particular, the first image may be a luminescent print, for example a luminescent print printed on a black opaque background of the security article, onto which the second image is projected under UV illumination. The first image is then only visible under UV illumination.

The first image may also be printed on a luminescent background of the security article so that the first image is visible both under UV lighting and under normal lighting.

The first image may be concealed within the pattern of the security article. The first image may also be integrated into the pattern of the security article or constitute at least a portion of the pattern of the security article. As an example, the first image constitutes a portion of a person's hair displayed on a banknote.

The first image may comprise a revelation frame and the second image may comprise a combined image comprising at least two interlaced images and associated with the revelation frame, or vice versa.

The term "associated" has to be understood to mean that the presentation frame is advantageously adapted to enable the observation of the various interlaced images of the combined image.

In particular, a person skilled in the art will modify the resolution of the electronic imager and/or the second image and the first image to allow viewing of various interlaced images of the combined image.

As mentioned above, the presence of several first images enables authentication and/or identification of the security article independently of the electronic imager used, and in particular independently of the resolution of the electronic imager.

By relative movement of the display frame with respect to the combined image, at least partial superposition of the first and second images enables continuous observation of the interlaced image of the combined image. Thus, the security article can be authenticated and/or identified by reconstructing the interlaced image, which at least partially constitutes an item of authentication and/or identification information for the security article.

For example, reconstruction of interlaced images can cause motion artifacts, especially in animation.

The electronic imager may comprise a screen, such as those previously described, the pixels of which are at least partially used to form the second image in the form of a presentation frame. Advantageously, the first image comprises a combined image associated with a presentation frame, the presentation frame thus being formed at least partially by the pixels of the screen.

In particular, the frame lines and/or the dots of the display frame can be formed by pixels of a screen of an electronic imager.

The screen may comprise pixels forming at least two display frames having different resolutions. In particular, the screen may comprise two display frames having different spacings between frame points and/or frame lines and/or different thicknesses of frame points and/or frame lines.

The display frame may be formed by a continuous multi-colored line formed by screen pixels, in particular, the multi-colored line comprising pixels having three units (red, green and blue of the RGB type), the pixels being spaced apart from one another to form a single-color line without pixels, in particular a black line. Pixels may also have four units, namely red, green, blue and yellow.

In this way, the pixels of the screen can form the inherent display framework of the screen without the need to display a specific image on the screen. For example, by turning on the red cells, green cells and blue cells of all the pixels of the image, the screen can be illuminated with white in a uniform manner.

The imager can be used in two ways. In the first case, an image corresponding to the non-uniform switching of the pixels of the imager is displayed. In the second case, all pixels of the imager are switched on in a uniform manner and an inherent framework derived from the arrangement of the pixel cells within the imager is utilized.

Thus, by observing the interlaced images in the relative movement of the first image in the form of the combined image with respect to the second image in the form of the presentation frame, it is possible to observe a monochrome animation of the interlaced images according to a first movement of the first and second images relative to each other, and a multi-colored animation of the interlaced images according to a second movement of the first and second images relative to each other, the second movement occurring in a direction different from the first movement, preferably perpendicularly.

The combined image and the interlaced images it comprises can be framed images. In other words, the various grayscale levels of the image can be obtained by using frame dots and/or frame lines. For example, the framed image can be a halftone image, which can, in particular, present color gradations, such as grayscale, based on the grouping of frame dots.

The combined image may correspond to a decomposition of the motion of a pattern, such as a text pattern, an alphanumeric symbol pattern, an ideographic pattern, an object pattern, a person pattern, and/or an animal pattern. The interlaced image may show the sequential position and/or sequential motion of a pattern, such as the sequential position and/or sequential motion of an object, a person, and/or an animal.

Advantageously, the combined image is obtained by superimposing interlaced images, each interlaced image showing one position of the pattern.

Interlaced images can reveal hidden information which is revealed successively by relative movement of the revealing frame over the combined image, in particular by translation.

Preferably, the combined image maintains a recognizable aesthetic, in particular to constitute a first authentication element.

The presentation frame allows the human eye to see different interlaced images at once, enabling, for example, the observer's brain to reconstruct motion or observe hidden items of information.

Within the meaning of the present invention, the expressions "framed image" and "display frame" must be understood in a specific broad sense, covering all types of frames or pseudo-frames comprising juxtaposed mutually contrasting areas, such as light and dark areas that are distinguishable from each other, the shapes of these light and dark areas being not limited to specific shapes.

For example, the composite image and/or display frame may include a set of dots and/or a set of parallel or non-parallel lines whose size and/or mutual spacing are variable or fixed, which are arranged to form a series of light and dark areas, such as white areas and black areas.

In particular, when the combined image and/or the presentation frame comprises a set of points arranged, for example, according to rows and/or columns, the viewing of the interlaced image can be achieved by translation in at least two directions, in particular a direction parallel to the rows and a direction parallel to the columns.

The combined image and/or the display frame may in particular comprise a set of lines, preferably mutually parallel lines, with a defined thickness and mutual spacing. In particular, the lines may have the same thickness and/or the same mutual spacing.

For example, the combined image and/or the presentation frame may include continuous dark and light bars, such as black and white lines. For example, the thickness of the dark bars of the combined image may be equal to the thickness of the light bars of the presentation frame. For example, the thickness of the light bars of the interlaced image may be equal to the thickness of the dark bars of the presentation frame.

The display frame may comprise an opaque strip with parallel edges which are optionally non-straight. The presence of an opaque strip with non-straight edges makes it more difficult for a counterfeiter to replicate.

The revelation frame may comprise strip portions of substantially the same colour or colour as the strips of the combined image and arranged to mask certain strips of the combined image to achieve the desired effect.

Preferably, the area, in particular the length and/or width and/or the maximum dimension of the presentation frame can be greater than or equal to the area, in particular the length and/or width and/or the maximum dimension of the combined image. In this way, a complete reconstruction of the movement resulting from the relative displacement between the combined image and the presentation frame can be seen.

The display frame may have any shape, such as a circular shape, an oval shape, a star shape, a polygonal shape, such as a rectangular shape, a square shape, a hexagonal shape, a pentagonal shape, a diamond shape, or other shapes.

The security article may comprise a first portion of a display frame or a first portion of a combined image, and the electronic imager may comprise another portion of the display frame or another portion of the combined image. The security article and the optical imager may be arranged to bring together the two separate portions of the display frame or the two separate portions of the combined image to implement the method according to the present invention.

According to a variant of the present invention, two composite images of different sizes can be associated. The composite image of smaller size can be repeated, in particular using a grid, in particular a grid consisting of rows and columns, to form a background against which the composite image of larger size is placed. The associated presentation frame then comprises a first presentation frame for the composite image of larger size and a second presentation frame for the composite image of smaller size. The two different composite images can appear similar and/or complement each other. In particular, the two different composite images can be identical and/or symmetrical.

The first image may be transferred to the security article by a printing method, such as offset printing, copperplate printing, laser printing, gravure printing, relief printing or screen printing.

For example, the first image can be printed using colored ink or achromatic ink, which is visible to the naked eye, is opaque or luminescent under ultraviolet (UV) and/or infrared (IR) light, in particular is fluorescent, thermochromic, photochromic, and has an interference effect, in particular a glittering effect, or an optically variable effect depending on the observation angle (goniochromatic effect), and the colored ink or achromatic ink includes in particular liquid crystal ink, metallic ink or non-metallic ink, magnetic ink or non-magnetic ink, and others.

The first image may also include metallization and/or demetallization, for example of aluminum. Advantageously, metallization and/or demetallization can be used to prevent counterfeiting by printing. In particular, metallization and/or demetallization with different colors, for example of aluminum and copper, is preferably used.

The first image may contain a watermark and a pseudo-watermark.

Watermarks are produced using techniques well known in the papermaking art. Pseudo-watermarks reproduce the appearance of a watermark by exhibiting differences in opacity. These pseudo-watermarks can be mechanically applied with or without heat, and/or chemically applied with a composition, such as a transparentizing agent that locally increases the transparency of the paper. The density of the fibrous material of the pseudo-watermark can be uniform compared to conventional watermarks.

The first image and the second image may be colored, in particular have different colors.

The first image may be carried by a patch and/or foil which is essential to the security article.

The patch and/or foil may comprise metallization and/or demetallization, for example of aluminum, or any type of printing.

The patch and/or foil may comprise a holographic print and/or liquid crystals.

The first image may also be carried by a security thread that is integrated on the surface of the security article, inside the security article, or as a window in the security article.

The security thread may have a width sufficient to allow the first image to be made to appear entirely within the security thread. For example, the width of the security thread is between 3 mm and 20 mm, and preferably between 4 mm and 10 mm.

Advantageously, the first image appears on an area of the article that is at least partially transparent.The first image may be at least partially transparent.

The at least partially transparent area may correspond to a recess in the article where the first image is located, with or without penetration through.

For example, this area is formed of a translucent coated paper.

The region may also comprise or consist of a polymer layer, for example, a polymer layer comprising polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), polyester carbonate (PEC), polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS); or a light concentrating film, for example of the “waveguide” type, such as the polycarbonate-based light-emitting film sold by the company BAYER under the trade name . When a waveguide film is used, the first image is preferably obtained by laser etching.

The area can also be made transparent by applying a generally fatty composition that renders it permanently transparent, such as the compositions made of oil and of transparent mineral materials described in patent US2021141, or compositions in the form of waxes combined with solvents, such as those described in patent US1479437.

As described in patent US5118526, it is also possible to make areas transparent by locally applying wax through heat transfer.

For this zone, it is also possible to use a fiber layer comprising a thermofusible substance, such as polyethylene as described in patent EP 0 203 499, the transparency of which changes under the effect of local heating.

The security article and the elements comprised by the security article, such as the first image, the window, the security thread, the patch containing or not containing the first image and/or the foil, may comprise one or more additional security elements as defined hereinafter.

Some of these additional security elements are detectable by eye under daylight or artificial lighting without the use of specific devices. For example, these security elements include colored fibers or colored flakes or partially or completely metallized or printed threads. These security elements are so-called first-level security elements.

Other types of additional security elements can only be detected with relatively simple devices, such as lamps that emit ultraviolet (UV) or infrared (IR). These security elements include, for example, fibers, sheets, strips, threads, or particles. These security elements can be visible or invisible to the naked eye; for example, they may glow when illuminated by a Wood's lamp at a wavelength of 365 nm. These security elements are considered second-level.

Detection of other types of additional security elements requires more sophisticated detection equipment. For example, these security elements can generate a specific signal when simultaneously or independently stimulated by one or more external excitation sources. Automatic detection of this signal can, if appropriate, authenticate the item. For example, these security elements can include tracers in the form of active substances, active particles, or active fibers that generate a specific signal when stimulated by photoelectric, electrical, magnetic, or electromagnetic excitation. These security elements are classified as Level 3.

Security articles and the components they contain may have first-level, second-level, or third-level security features.

In particular, the first image may be associated with a metallization effect, a luminescent effect (eg fluorescence and/or phosphorescence), a thermochromic effect (eg thermochromic inks), a magnetic effect, a polarization effect (eg liquid crystal inks), this list not being limiting.

Security items can be: payment instruments, such as banknotes, checks or restaurant vouchers; identification documents, such as identity cards, visas, passports or driving licenses; lottery tickets; train tickets; or tickets for cultural or sporting events; or access cards, for example for access to restricted areas.

In particular, the security article can be an access card comprising a first image, for example in the form of a composite image, with the card holder being present at an access control point, for example an access control point of a company, at which the method according to the invention is implemented, for example by means of a second image in the form of a display frame to authorize access.

According to another aspect of the invention, the subject matter of the invention is also a security article, in particular a security document, for implementing the method defined above.

According to another aspect of the present invention, the subject matter is also a method for authenticating and/or identifying a security article, in particular a security document, comprising a first image and an integrated microcircuit, in particular an RFID chip and an optical chip, comprising the following steps:

- causing the first image of the security article to at least partially superimpose a second image generated by the electronic imager, the second image being generated following communication between the integrated microcircuit and the electronic imager; and

- observing an item of authentication information and/or identification information for the security article, in particular by a relative movement between the first and second image and/or by a change in the angle of observation of the at least partially superimposed first and second image.

According to another aspect of the present invention, the subject matter is also a method for authenticating and/or identifying a security article, in particular a security document, comprising the following steps:

- at least partially superimposing a first image of the security article with a second image generated by an electronic imager, the second image being based on a photograph and/or video of the security article, in particular the first image generated by the electronic imager; and

- observing an item of authentication and/or identification information for the security article, in particular by a relative movement between the first and second image and/or by a change in the angle of observation of the at least partially superimposed first and second image.

The photos and/or videos may be generated by an electronic imager to which an image capture device (e.g., a digital camera) is connected, and/or the photos and/or videos may be transmitted to the electronic imager, for example, from a device for storing data or via a network (e.g., the Internet).

According to another aspect of the invention, the subject of the invention is also a security article comprising a first image superimposable on at least one second image generated by an electronic imager, the first image being defined in particular by a first polarizing material.

A first polarizing material may be superimposed onto a second polarizing material, the first polarizing material preferably being a print of cholesteric liquid crystal, and the second polarizing material preferably being a linear polarizing substrate.

The first image may be defined by providing a polarizing substrate that is partially non-polarizing to form the first image.

The first image may be defined by printing with polarizing ink.

The security article may comprise several different first images, each first image being superimposed on at least one second image appropriate to the first image generated by an electronic imager, in particular having a different resolution.

According to another aspect of the invention, the subject of the invention is also a security article comprising several different first images, each superimposable onto at least one second image adapted thereto, generated by an electronic imager, in particular having a different resolution.

The security article can be used in the method described above. The features described in conjunction with the method according to the invention can be applied to the security article.

According to another aspect of the invention, the subject of the invention is also a method for producing a first image of a security article as defined above, wherein:

- depositing a metal layer on an at least partially transparent substrate;

- applying an ink or lacquer, which may be pigmented or matte, to the metal layer by printing, coating or deposition to form a first image; and

- Selective demetallization of an area or areas not covered with ink or lacquer.

The ink or lacquer may be selected to be compatible with the demetallization method.

For example, the demetallization process may correspond to a soda chemistry process that removes metal in the area or areas not covered by the ink or lacquer.

The demetallization process may also include the application of a lacquer or ink, which may be matte or colored and have optical properties that differ from those of the metal layer.

The ink can be selected from visible colored or colorless inks that are opaque or luminescent (especially fluorescent) under UV and/or IR light, thermochromic, photochromic, have an interference effect, especially a shimmering effect, or have an optically variable effect depending on the viewing angle (goniochromatic effect), especially liquid crystal inks, metallic or non-metallic inks, magnetic or non-magnetic inks, and others. Preferably, the ink fluoresces and/or phosphoresces under UV and/or IR light.

The security article also comprises, for example, the first and/or second level security elements described above. In particular, the security article may comprise a security element in the form of a print and/or marking, in particular a thermochromic security element or a photochromic security element.

By means of the manufacturing method according to the invention, a first bright metallic image is observable on a first side of the security article and a first image having the appearance of ink or lacquer, for example a colored or matte first image, is observable on an opposite second side of the security article.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood after reading the following description of non-limiting examples and their implementation and with reference to the schematic and partial drawings of the accompanying drawings, in which:

- FIG1 shows a block diagram of the steps performed in an exemplary method according to the present invention;

- Figures 2 to 4 show examples of an association of a security article with an electronic imager to implement an example of the method according to the invention;

- FIG5 shows an exemplary electronic imager displaying an indicator;

- FIG6 shows an exemplary security article comprising a security element and an integrated microcircuit;

- Figure 7 shows a series of interlaced images that can form a combined image;

- FIG8 shows a combined image based on the series of interlaced images of FIG7 ;

- FIG. 9 illustrates an exemplary presentation frame that may be associated with the combined image of FIG. 8 ;

- Figures 10 to 14 show exemplary embodiments of a security article comprising a first image in the form of a composite image or a display frame;

FIG. 15 shows an example of a first image or a second image comprising two different combined images for implementing an example of the method according to the invention;

FIG. 16 shows an exemplary first image or second image containing a revelation frame, associated with the combined image of FIG. 15 , for implementing an example of the method according to the invention;

- Figures 17 and 18 illustrate an exemplary first image and an exemplary second image, respectively, each image comprising a presentation frame and a combined image;

- Figures 19 to 21 show an exemplary implementation of the method according to the invention, with a security article comprising a first image in the form of a display frame and a second image generated by an electronic imager in the form of a combined image;

- Figures 22 and 23 show another exemplary embodiment of the method according to the invention, wherein the security article comprises a first image in the form of a combined image and a second image generated by an electronic imager in the form of a display frame;

- Figures 24 to 26 show another exemplary implementation of the method according to the invention; and

- Figures 27 to 31 show further examples of implementing the method according to the invention.

DETAILED DESCRIPTION

FIG1 shows a block diagram relating to the steps performed in an exemplary method according to the present invention.

In a first step I, a first image of the security article is at least partially superimposed with a second image generated by an electronic imager.

In a second step II, a relative movement is generated between the first image and the second image.

Finally, in a third step III, an item of information authenticating and/or identifying the security article is observed, this item of information appearing during the relative movement between the first image and the second image.

Step I, step II, and step III may be performed simultaneously or may not be performed simultaneously.

An example of an association between a security article 1 and an electronic imager 10 , which enables the implementation of such a method, is shown in FIGS. 2 to 4 .

In FIG. 2 , the electronic imager 10 is, for example, a computer screen on which the second image 30 is displayed.

For example, the security article 1 is in the form of a banknote and comprises a first image 20 .

According to the steps described in Figure 1, the security article 1 is placed on the screen of the electronic imager 10 so that the first image 20 is at least partially superimposed on the second image 30, and then the security article 1 is shifted relative to the screen of the electronic imager 10 to observe the information item that verifies and/or identifies the security article 1.

As a variant, the reference security article 1 remains stationary relative to the screen of the electronic imager 10 , while the second image 30 is animated by movement (for example translation) on the screen, for example with the help of a program activated or not by the user.

In FIG. 3 , the electronic imager 10 is, for example, in the form of a digital projector, which projects the second image 30 onto a background 50 , for example onto a wall of a room.

The security article 1 comprising the first image 20 may then be at least partially superimposed on the second image 30 projected onto the background 50 , in order to carry out the steps described with reference to FIG. 1 .

In FIG. 4 , the electronic imager 10 is a projector which projects the second image 30 directly onto the security article 1 .

As in the example of FIG4 , second image 30 may be projected, for example, in the form of a "W" onto an area of security article 1 where first image 20 is not present. Next, for example, security article 1 may be folded upon itself so that first image 20, for example in the form of an "A," is superimposed on second image 30 projected by electronic imager 10, to implement the steps described in FIG1 . In particular, the portion of security article 1 containing first image 20 may be folded back over the portion containing second image 30 (which remains stationary) in such a way that second image 30 is positioned between imager 10 and first image 20.

In a variant (not shown), the second image 30 is projected directly onto the first image 20 of the article 1. In particular, projecting the second image 30 onto the first image 20 of the article 1 may allow at least partial superposition of the first and second images. Subsequently, for example, the electronic imager 10 is displaced relative to the security article to carry out steps II and III as described with reference to FIG. 1 .

In FIG. 5 , a variant embodiment is shown, in which the electronic imager 10 is a screen displaying several second images 30 a , 30 b , 30 c and 30 d .

The second images 30 a to 30 d may have different attributes, such as different shapes, different colors, different sizes, different dots, or different frame lines.

Advantageously, the second images 30a to 30d are distinct in order to allow at least one of them to be associated with at least one first image 20 present on the security article 1. In this way, for example, a more diverse range of security articles 1 having different corresponding first images can be authenticated and/or identified corresponding to the various second images 30a to 30d.

As a variant, the security article 1 comprises several different first images 20, as can be seen, for example, in FIG14 , and the electronic imager 10 generates one or more second images 30. In this way, a given security article 1 can be authenticated and/or recognized, for example, on a wider variety of different electronic imagers, in particular with different resolutions. In this way, the two advantages previously described can be combined.

Electronic imager 10 may display one or more indicators 40a, 40b, 40c, and 40d that can advise the user as to how to position security article 1 according to the imager.

In particular, indicators 40a to 40d make it possible to know where to position the upper right corner of security article 1 so that first image 20 of security article 1 is correctly superimposed on second image 40a, 40b, 40c or 40d displayed on the screen of electronic imager 10.

FIG. 6 shows a security article 1 comprising an additional security element 51 of any known type, for example one of those previously described, such as a luminous security thread.

Furthermore, the security article 1 may comprise an integrated microcircuit 52 , such as an RFID or an optical chip, which can communicate with the electronic imager 10 to control the display of indicators such as those previously described or to communicate items of information regarding how the first and second images are positioned.

In particular, in the examples described previously, the first image 20 may comprise a revelation frame 3 and the second image 30 may comprise a combined image 2 comprising at least two interlaced images 2a, which, as mentioned above, is associated with the revelation frame 3, or vice versa.

The following Figures 7 to 26 illustrate this possibility.

In FIG. 7 a series of interlaced images 2 a is shown which may form a combined image 2 , which can be seen in FIG. 8 , which shows a pattern in this example in the form of an elephant.

For example, the interlaced image 2a corresponds to four different postures of the elephant, thus enabling a decomposition of the elephant's movement.

Each interlaced image 2a may comprise a series of parallel lines as shown, the parallel lines being spaced apart in a regular or irregular manner and having varying thicknesses.

The images 2 a are superimposed on each other to form a combined pattern corresponding to the combined image 2 .

FIG. 9 shows an exemplary revelation frame 3 , which may be associated with the combined image 2 of FIG. 8 .

For example, the display frame 3 has a rectangular shape and comprises a set of parallel lines that are spaced apart in a regular or irregular manner and have varying thicknesses.

The display frame 3 has an area, length and width that are larger than those of the combined image 2 , so that the overall movement of the elephant can be more easily seen during the relative displacement between the combined image 2 and the display frame 3 .

In this example, the combined image 2 and the display frame 3 comprise groups of alternating light and dark lines, in particular black and white lines, but also other lines. For example, the lines may be colored and different for the combined image 2 and the display frame 3.

10 to 14 show exemplary embodiments of a security article 1 for implementing the method according to the invention.

In Figure 10, the security article 1 comprises a window 4, preferably an at least partially transparent window, in which a first image 20 appears in the form of a display frame 3. For example, the first image 20 can be formed by printing (especially copperplate printing), metallization or demetallization.

In FIG. 11 , the security article 1 comprises a patch 5 in which a first image 20 appears in the form of a revelation frame 3 , for example the patch 5 comprises a holographic print.

The patch 5 may be at least partially transparent.

The display frame 3 may comprise a holographic print and/or metallization and/or demetallization.

In FIG. 12 , the security article 1 comprises a security thread 6 in which a first image 20 appears in the form of a combined image 2 .

The security thread 6 can also be at least partially transparent or comprise at least partially transparent areas at the level of the combined image 2 .

In FIG. 13 , the security article 1 comprises a security thread 6 in which a first image 20 appears in the form of a revelation frame 3 .

The security thread 6 may be at least partially transparent or have areas that are at least partially transparent.The display frame 3 may extend from one edge of the security article 1 to an opposite edge.

In Figure 14, the security article 1 comprises a security thread 6 comprising several first images 20 in the form of combined images 2. The first images 20 are produced in such a way that the security article 1 can be used with different electronic imagers, in particular with different resolutions, each first image 20 being adapted to the specific resolution of the electronic imager.

The security thread 6 can be at least partially transparent or comprise at least one at least partially transparent region, in particular at the level of the combined image 2 .

The several first images 20 appearing on the security article 1 and arranged on the security thread 6 make it possible to simplify the method for manufacturing the security article 1 by incorporating the security thread 6 into a substrate, in particular a fibrous substrate. In particular, the incorporation of data is not necessarily necessary.

In all the examples described previously, the combined image 2 and the revelation frame 3 are interchangeable.

The at least partially transparent area may be positioned at the level of the combined image 2 or at the level of the presentation frame 3 or at the level of both the combined image 2 and the presentation frame 3 .

The security thread 6 can be introduced into the security article 1 in a conventional manner, for example on the surface, or on the inside or as a window.

The combined image 2 and/or the display frame 3 may also comprise a polarization filter. The security article 1 can then be authenticated and/or identified by means of an electronic imager 10 emitting polarized light.

15 , a second image 30 (or first image) is diagrammatically shown, which comprises two different combined images 21 and 22. The second combined image 22 is, for example, a symmetrical image of the first combined image 21 after its dimensions have been modified to obtain a network of combined images 22 organized into rows and columns.

FIG16 shows the corresponding first image 20 (or second image), which is diagrammatically shown in FIG16 in the form of a display frame 3 of interlaced images 21a and 22a. This display frame 3 comprises an association of two base frames 3c and 3d, in which interlaced images 21a and 22a are respectively visible. For example, frame 3c comprises a series of black stripes that alternate with stripes of frame 3d, which is composed of alternating black and white lines with smaller spacing.

In FIG. 17 , a first image 20 (or a second image) is diagrammatically shown in the form of a combined image 22 arranged around a display frame 31 according to a web of the combined image 22 .

In FIG. 18 , a second image 30 (or first image) is diagrammatically shown in the form of a combined image 21 surrounded by a revelation frame 32 .

19 to 21 show an exemplary implementation of the method according to the invention.

In this example, the electronic imager 10 takes the form of a mobile phone, for example, on which a second image 30 in the form of a combined image 2 is displayed (visible in FIG. 21 ).

Furthermore, the security article 1 comprises a polarisation filter on which a first image 20 in the form of a revelation frame 3 is formed.

FIG. 20 shows a security article 1 comprising a first image 20 in the form of a revelation frame 3 , superimposed on a second image 30 in the form of a combined image 2 produced by an electronic imager 10 emitting polarized light.

The user moves the security article 1 so that it is in a crossed orientation which enables the opacity of the polarising filter to be observed in relation to polarised light.

21 , the security article 1 comprising the display frame 3 is subjected to a translational movement along the arrow F relative to the combined image 2 displayed by the screen of the electronic imager 10, so as to present an animated display of interlaced images. This displacement is carried out while maintaining the relative orientation of the frame with respect to the screen.

Such a method makes it possible to authenticate and/or identify the security article 1 according to several security levels.

A first level of security is provided by positioning the display frame 3 containing the polarising filter according to an orientation in which its opacity can be observed, this observation being visible only on a screen emitting polarised light, for example a screen of LCD type.

The animation of the interlaced images, revealed by the displacement of the revealing frame 3 relative to the combined image 2, provides a second level of security.

22 and 23 show another exemplary implementation of the method according to the present invention.

In this example, the electronic imager 10 is preferably a screen comprising a plurality of pixels, in particular of the LCD type.

FIG. 22 partially shows the electronic imager 10 in the form of an LCD screen including a plurality of pixels, and FIG. 23 shows an enlarged portion of FIG. 22 .

The set of pixels of this screen forms a second image 30 in the form of a presentation frame 3 .

As can be seen in Figure 23, the screen may comprise a regular arrangement of pixels arranged in horizontal and vertical lines. In particular, a horizontal line may comprise a repetition of three pixels _P1 , _P2 and _P3 of different colors (eg RGB).

Furthermore, as can be seen in FIG. 23 , horizontal lines of pixels may be separated by black areas N containing no pixels.

In this way, when the combined image 2 of the security article 1 is superimposed on the screen of the electronic imager 10 containing the display frame 3, the relative movement in the horizontal direction can display a multi-color animation, which allows the observation of the interlaced image, and, after rotating the combined image 2 by 90°, the relative movement in the vertical direction can display a monochrome animation, allowing the observation of the said interlaced image.

According to a variant, the combined image 2 and the display frame 3 are designed to allow the observation of an animation resulting from relative movement in two different directions (particularly in the vertical direction). For example, such an effect can be achieved by a display frame 3 composed of rows and columns of dots, for example a square-shaped display frame, or by a suitable combined image 2, such as the combined image 2 shown in FIG. 25 .

The electronic imager 10 may correspond to a mobile phone screen, for example a mobile phone screen having a resolution of 160 dpi, resulting in a display frame whose pixels are spaced at 159 μm.

The combined image 2 present on the security article 1 may appear in a through-window of the security article 1, which through-window is sealed by a transparent plastic strip. The transparent plastic strip may have the properties of a circular polarising filter.

A security article 1 comprising a polarizing transparent plastic strip on which a composite image 2 is formed can be manufactured so that the polarization properties are preserved over the constituent areas of the composite image, for example, with several consecutive spiral positions. Thus, the composite image 2 can be produced in the manner previously described, for example by printing the plastic strip with a special ink imparting polarization properties or by heating the areas where the polarization properties are to be removed, for example, using a laser.

A further exemplary embodiment of the method according to the invention is shown in FIGS. 24 to 26 .

In this example, the electronic imager 10 in the form of a screen comprises a first portion 30 a of the second image in the form of a revelation frame 3 a , as shown in FIG. 24 .

The security article 1 comprises a further portion 30b of the second image in the form of a display frame 3b, for example in an at least partially transparent window of the security article. Furthermore, the security article 1 comprises the first image 20 in the form of a combined image 2, for example in an at least partially transparent window of the security article, as can be seen in FIG.

The method according to the invention can be implemented by the relative movement of the portion of security article 1 containing combined image 2 relative to the portion of security article 1 containing portion 3b of the display frame, when security article 1 is folded over itself so that combined image 2 is superimposed on portion 3b of the display frame and, consequently, on electronic imager 10, so that combined image 2 and portion 3b of the display frame are superimposed on portion 3a of the display frame formed on the screen of electronic imager 10, while the portion of security article 1 containing portion 3b of the display frame remains stationary relative to the screen containing portion 3a of the display frame, so as to allow reconstruction of the display frame and observation of the interlaced images, as shown in FIG26 . Advantageously, combined image 2 allows the observation of an animation or two animations resulting from relative movement in two different directions, in particular perpendicular directions.

FIG. 27 shows an exemplary security article 1 in the form of a passport, comprising a first image 20 printed in the form of a combined image 2 and an RFID chip 60 .

The chip 60 is capable of communicating with the electronic imager 10 (not shown) to enable the generation of the second image 30 associated with the first image 20 .

In particular, the first image 20 is illuminated by means of an electronic imager during use for verification and/or identification of the passport 1. The chip 60 contains an item of information which is transmitted to the electronic imager which then projects the second image based on this item of information.

FIG. 28 shows a further exemplary embodiment of the method according to the invention.

In this example, the security article 1 in the form of a passport comprises a first image 20 in the form of a combined image 2 obtained by metallizing a transparent plastic film inserted into the passport via a window 4 .

The passport 1 (particularly the combined image 2) is photographed or filmed using a digital camera 70, which is part of or associated with an electronic imager. A recognition program then recognizes the combined image 2 and retrieves a second image associated with the first image from a database, for example, stored on a secure server. The resulting second image is displayed and/or projected by the electronic imager, allowing verification and/or identification of the passport 1 by the relative motion of the first and second images.

Figure 29 shows a security article 1 in the form of a banknote.

The security article 1 comprises a first printed image 20, for example showing a human face, comprising a combined image 20, for example on the level of human hair. Preferably, the combined image 2 appears in a transparent, translucent or reduced opacity area of the security article 1.

For verification and/or identification of the banknote 1 , for example, the banknote can be photographed, in particular the first image 20 , thereby generating a second image linked to the first image, which is based on a photograph of the banknote.

For example, the electronic imager is a mobile phone capable of taking pictures of banknotes, and a program inside the mobile phone can download a second image associated with the first image, which can then be displayed on the screen of the mobile phone to implement the method according to the invention.

According to a variant, said program inside the mobile phone can generate said second image associated with said first image.

Figures 30 and 31 show in cross-section two examples of security articles comprising a light-emitting area.

In Figure 30, the security article 1 comprises a substrate 80 on which a black opaque layer 81 is printed. For example, the substrate 80 is completely covered by the black opaque layer 81.

Furthermore, a first luminescent image 20 , for example in the form of a composite image, is printed on the black opaque layer 81 , in particular a fluorescent image or a phosphorescent image.

An associated electronic imager (not shown), under ultraviolet (UV) illumination, is capable of projecting a second image 30 (not shown) onto the first image 20 .

In this way, the first image 20 is not observable under normal lighting due to the presence of the black opaque layer 81. On the other hand, under UV illumination, the first image 20 is observable and it is possible to at least partially superimpose the second image 30 (in particular in the form of a display frame) on the first image 20 in order to implement the method according to the invention.

In FIG. 31 , the first image 20 is printed with a black opaque ink on a luminescent layer 81 , in particular fluorescent and/or phosphorescent, which is printed on a substrate 80 .

In this example, the first image 20 is viewable both under normal lighting and under UV illumination.

The term "comprising" has the same meaning as "comprising at least one".

Claims (33)

1. A method for verifying and/or identifying a security item (1) comprising a first image (20), the method comprising the steps of: - The first image (20) of the security item (1) is at least partially superimposed with the second image (30) generated by the electronic imager (10); - Relative motion is performed between the first image (20) and the second image (30) to enable the observation of verification information items and/or identification information items for the security item (1) during the relative motion between the first image (20) and the second image (30), which are unavailable except during the relative motion between the first image and the second image. During the relative motion between the first image (20) and the second image (30), motion effects or animation effects are observed; The observed motion or animation effect is the motion or animation effect of the interlaced image (2a). 2. The method of claim 1, wherein the first image (20) comprises a display frame (3) and the second image (30) comprises a composite image (2), the composite image (2) comprising at least two interlaced images (2a), the composite image (2) being associated with the display frame (3), or vice versa. 3. The method of claim 1, wherein the first image (20) is defined by a first polarizing material superimposed on a second polarizing material. 4. The method of claim 3, wherein the first polarizing material is a cholesteric liquid crystal print and the second polarizing material is a linear polarizing substrate. 5. The method of claim 1, wherein the electronic imager (10) includes a screen, the pixels of which are at least partially used to form the second image (30) in the form of a display frame (3). 6. The method of claim 1, wherein the electronic imager (10) is a projector. 7. The method of claim 1, wherein the security article (1) includes an integrated microcircuit (60) capable of communicating with the electronic imager (10) so that the electronic imager (10) generates a second image (30) associated with the first image (20). 8. The method of claim 1, wherein the security article (1) includes an area containing the first image (20) that is at least partially transparent, semi-transparent, or has reduced opacity. 9. The method of claim 8, wherein the security item (1) includes at least a partially transparent window (4). 10. The method of claim 1, wherein the second image (30) is displayed on the electronic imager (10). 11. The method of claim 10, wherein the second image (30) is displayed on the screen of the electronic imager (10). 12. The method of any one of claims 1 to 9, wherein the second image (30) is projected by the electronic imager (10). 13. The method of claim 12, wherein the second image (30) is displayed on the background (50) or on the security item (1). 14. The method of claim 1, wherein the relative motion of the first image (20) with respect to the second image (30) is a translational motion and/or a rotational motion. 15. The method of claim 1, wherein the relative motion is generated by displacement of the electronic imager and/or the security item. 16. The method of claim 1, wherein the relative motion is generated by a change in the image produced by the electronic imager. 17. The method of claim 1, wherein the electronic imager (10) comprises a liquid crystal display (LCD). 18. The method of claim 1, wherein the first image (20) and the second image (30) have polarization characteristics. 19. The method of claim 18, wherein the electronic imager (10) generates the second image (30) using polarized light, and the first image (20) includes a polarizing filter. 20. The method of any one of claims 16 and 17, wherein the first image (20) and the second image (30) are positioned by successively orienting themselves to allow one image to partially obscure the other before the verification information item and/or identification information item are observed during relative motion between the first image (20) and the second image (30). 21. The method of claim 1, wherein the security article (1) comprises several different first images (20) and/or the electronic imager (10) generates several different second images (30a, 30b, 30c, 30d). 22. The method of claim 1, wherein the electronic imager (10) generates at least one second image (30) based on photographs and/or videos of the security item (1). 23. The method of claim 22, wherein the electronic imager (10) generates at least one second image (30) based on a photograph and/or video of the first image (20). 24. The method of claim 1, wherein the relative motion between the first image (20) and the second image (30) is a physical motion between the security item (1) and the electronic imager (10). 25. A method for verifying and/or identifying a security item (1) containing a first image (20), the method comprising the steps of: - The first image (20) of the security item (1) is at least partially superimposed with the second image (30) generated by the electronic imager (10); - Relative motion is performed between the first image (20) and the second image (30) to enable the observation of verification information items and/or identification information items for the security item (1) during the relative motion between the first image (20) and the second image (30), which are unavailable except during the relative motion between the first image and the second image. The first image (20) includes a display frame (3), and the second image (30) includes a composite image (2) which includes at least two interlaced images (2a) and is associated with the display frame (3), or vice versa. 26. A security article (1) comprising a first image (20) superimposed on at least one second image (30) generated by an electronic imager (10), the first image (20) being defined by a first polarizing material, the first image (20) comprising a display frame (3), and the second image (30) comprising a composite image (2) comprising at least two interlaced images (2a) associated with the display frame (3), or vice versa. 27. The safety article of claim 26, wherein the first polarizing material is stacked on the second polarizing material. 28. The safety article of claim 27, wherein the first polarizing material is a cholesteric liquid crystal print and the second polarizing material is a linear polarizing substrate. 29. The security article of claim 27, wherein the first image (20) is defined by a polarization substrate that provides partial non-polarization to form the first image (20). 30. The security article of claim 27, wherein the first image (20) is defined by a print of polarizing ink. 31. The security article according to any one of claims 28 to 29, wherein the security article comprises a plurality of different first images (20), each first image (20) superimposed on at least one second image (30) generated by an electronic imager (10), the second image (30) being adapted to the first image. 32. The security article of claim 31, wherein the electronic imager (10) has a different resolution. 33. A method for creating a first image of a security article as claimed in claim 26, wherein: - Deposit a metal layer on a substrate that is at least partially transparent; - Applying ink or paint, whether colored or matte, to the metal layer by printing, coating, or deposition to form the first image; and - Selective demetallization is performed in areas not covered by the ink or paint.