Patent Application
20190009609
The present invention pertains to the field of secure items.
In order to guard against forgeries or falsifications and in order to increase the security level, it is known to use security elements applied on the surface or introduced bulk-wise or as window(s) into a secure item, for example a label, a packaging, especially for medicines, foods, cosmetics, electronic parts or spare parts.
The secure item may in particular be chosen from among a payment means, such as a banknote, a bank card, a check or a restaurant voucher, an identity document such as an identity card, a visa, a passport or a driver's license, a secure card, a lottery ticket, a transport pass or else an entry ticket for shows.
Effects of masking of interlaced images by a revealing raster allowing, when the revealing raster and the image are superposed, the observation of an image by displacing the revealing raster with respect to the image or by changing the angle of observation, are known from patent applications EP 2 367 695, EP 2 585 308 and EP 2 586 014 and from patent EP 2 454 102.
However, these patents are limited to the viewing of a single interlaced image at a time.
Also known from patent application EP 2 740 607 is a system comprising a revealing raster, a layer exhibiting pigments orientable by an external magnetic field and a magnetic layer exhibiting a raster of North and South poles, the revealing raster and the raster of North and South poles being of different colors. WO 2014 096 794 describes a first raster on which a second surface raster is embossed, the raster lines of the first raster exhibiting one and the same color in visible light and different colors when they are observed under a combination of visible light and invisible light and the two rasters being such that the device exhibits a different color, according to the angle of observation, when it is exposed to a combination of visible light and invisible light.
A need exists to benefit from secure items comprising an anti-forgery optical system using the tools of the players in the field of secure items, which is capable of producing optical effects able to contribute to the authentication and/or the identification of the item, and whose possible incorporation in an item such as a paper may be done relatively easily.
The invention is aimed at answering this need and a subject thereof is, according to a first of its aspects, a secure item comprising a first optical structure and a second optical structure, or an assembly comprising a secure item and another object, the secure item comprising one of a first optical structure and of a second optical structure and the object comprising or forming the other of the first optical structure and of the second optical structure,
the first optical structure comprising a plurality of blocks of first optical structure which are arranged in different regions of the first optical structure,
the first optical structure being one of a revealing raster and of a combined image and the second optical structure being the other of the revealing raster and of the combined image,
the combined image or, in the presence of combined-image blocks, each of the combined-image blocks, being composed of a plurality of interlaced images,
at least two blocks of first optical structure each allowing, when the revealing raster and the combined image are superposed, for at least one given position and given orientation of the revealing raster with respect to the combined image and for at least one angle of observation, the observation of an image revealed at the level of each block of first optical structure, the images revealed at the level of the two blocks of first optical structure unveiling different proportions of the interlaced images.
The fact that there are several blocks of first optical structure giving different revealed images makes it possible to have multiple visual effects in the various blocks.
By virtue of the invention, it is possible to benefit from a secure item offering a novel means of authentication, consisting of the formation of different revealed images, leading for example to the formation of a particular colored pattern easily recognizable by the man in the street.
The aforementioned other object is for example similar in its function and/or in its shape to the secure item according to the invention. For example, the secure item and the other object are banknotes, especially with the same fiduciary value. The secure item and the other object may then be differentiated one from the other only by a serial number for example.
By “the images revealed at the level of the two blocks of first optical structure unveiling different proportions of the interlaced images” is meant that each block unveils a certain proportion of each of the interlaced images of the combined image to form the revealed image. For each revealed image, the proportion of an interlaced image lies between 0 and 1, the value 0 being allocated to an interlaced image when the latter is not a component of the revealed image, that is to say when the latter is totally occulted by the revealing raster at the level of the corresponding block and the value 1 being allocated when the entirety of the interlaced image is a component of the revealed image, that is to say when the latter is not occulted at all by the revealing raster at the level of the corresponding block.
Thus, when the first optical structure is a revealing raster, the subject of the invention is a secure item comprising a revealing raster and a combined image, or an assembly comprising a secure item and another object, the secure item comprising one of the revealing raster and of the combined image and the object comprising or forming the other of the revealing raster and of the combined image,
the combined image being composed of a plurality of interlaced images,
the revealing raster comprising a plurality of blocks arranged in different regions of the revealing raster,
at least two revealing raster blocks each allowing, when the revealing raster and the combined image are superposed, for at least one given position and given orientation of the revealing raster with respect to the given combined image and for at least one angle of observation, the observation of an image revealed at the level of each block, the images revealed at the level of the two blocks unveiling different proportions of the interlaced images.
Thus, when the first optical structure is a combined image, the subject of the invention is a secure item comprising a revealing raster and a combined image, or an assembly comprising a secure item and another object, the secure item comprising one of the revealing raster and of the combined image and the object comprising or forming the other of the revealing raster and of the combined image,
the combined image comprising a plurality of blocks arranged in different regions of the combined image,
each combined-image block being composed of a plurality of interlaced images,
at least two interlaced-image blocks each allowing, when the revealing raster and the combined image are superposed, for at least one given position and given orientation of the revealing raster with respect to the given combined image and for at least one angle of observation, the observation of an image revealed at the level of each block, the images revealed at the level of the two blocks unveiling different proportions of the interlaced images.
Combined Image
Preferably, the combined image or each of the combined-image blocks comprises a periodic alternation of elements of images interlaced in one or more directions.
The combined image or each of the combined-image blocks may comprise at least two interlaced images, preferably at least three.
The combined image or each of the combined-image blocks may comprise at least two elements of each interlaced image, preferably at least three.
According to the or each of the directions, the successive elements of one and the same interlaced image may be mutually spaced by a distance defining a period.
The or each period may lie between 10 μm and 1 mm, preferably between 50 μm and 200 μm.
Preferably, the elements of interlaced images belonging to different interlaced images are of different colors. There is for example a colorimetric disparity ΔE*94 according to C.I.E. 1994 of greater than or equal to 2, preferably greater than or equal to 3. This makes it possible to have a polychrome combined image.
As is commonly admitted and specified in C.I.E. 1994, the color is defined by the combination of three parameters, namely hue, saturation and luminosity. Hue corresponds to the perception of the color measured on a chromatic disk, saturation corresponds to the purity of the color and luminosity corresponds to the degree of clarification or of darkening of a color.
Preferably, the elements of interlaced images belonging to different interlaced images are of different hues.
The elements belonging to different interlaced images, especially to at least two of the different interlaced images, may be different by their aspects, especially their hues, opacities, saturations, luminescences or brightnesses, and/or exhibit a contrast, especially a contrast of saturation, of intensity, of hue and/or of luminance, and/or a sufficient colorimetric disparity to make it possible to distinguish, especially under white light, two adjacent interlaced-image elements when they are observed with a certain enlargement. Thus, at least two of the, better all the interlaced images, are of different aspects.
The interlaced-image elements of one and the same interlaced image are, preferably, of the same color but of a different color from those of the other interlaced images. When superposing the revealing raster with the combined image, under given observation conditions, the image revealed by each of the blocks may then be an image whose color is defined by the proportion of each interlaced image that is visible, that is to say the proportion of each color. The images revealed at the level of at least two blocks are of different colors. For example, the combined image or each combined-image block comprises three interlaced images of respective colors red, green and blue and each revealed image is of a color dependent on its proportion in each of the interlaced images, the color being easily determinable by its RGB coordinates. The RGB coordinates take the form of three numbers lying between 0 and 255 characterizing said color, each number representing the proportion of one of the components red, green and blue making it possible to obtain said color.
By “under given observation conditions” is meant a given position and a given orientation of the revealing raster with respect to the combined image and a given angle of observation of the revealing raster and of the combined image.
The colors of the elements of interlaced images may or may not be primary colors.
Preferably, the combined image or each combined-image block, and the interlaced images that the image or the block comprises, are rasterized images; the combined image or each combined-image block may be a colored raster.
The elements of interlaced images may be fluorescent and exhibit aspects, especially colors, that differ under UV light. This makes it possible to have revealed images observable under UV light that may or may not differ from the revealed images observable in visible light.
When the elements of interlaced images are luminescent, they may or may not be visible in white light.
The elements of interlaced images are preferentially all of the same dimension in the or each of the directions.
The dimension of the elements of interlaced images in the or one of the directions is, preferably, equal to the period in this direction divided by the number of interlaced images. This dimension may be less than or equal to 1 mm, better less than or equal to 100 μm, better still less than or equal to 50 μm. Thus, the elements of interlaced images are adjoining. Each interlaced-image element may be partially superposed with one of the adjacent elements, the superposition width being less than or equal to 10%, better 5% of the dimension of the interlaced image element in said direction.
As a variant, at least two elements of interlaced images may be of different dimensions in the or one of the directions.
The elements of interlaced images have, preferably, the same general shape.
For example, the combined image or each combined-image block comprises a periodic alternation of interlaced image lines, of longitudinal axes which are mutually parallel in one direction. The longitudinal axes of the interlaced image lines define a general orientation of the combined image or of each combined-image block.
Each interlaced image may be formed of continuous or discontinuous lines, preferably continuous, two successive lines of the same interlaced image being spaced apart by a distance S defined between the longitudinal axes of the two adjacent lines, this latter defining the period of the combined image or of the combined-image block. The lines of one and the same interlaced image may or may not all be identical.
The lines of an interlaced image are, preferably, all of the same length. But it may be otherwise, and at least two interlaced image lines may be of different lengths.
Each line of an interlaced image is preferentially of constant width l over the whole of its length, its longitudinal edges being mutually parallel.
The interlaced image lines are, preferably, all of the same width.
The width l of the interlaced image lines is, preferably, equal to the period divided by the number of interlaced images. Thus, the interlaced image lines are adjoining. The width l of the interlaced image lines may be less than or equal to 1 mm, better less than or equal to 100 μm, better still less than or equal to 50 μm.
Each line of interlaced images may be partially superposed with one of the adjacent lines, the width of the superposition being less than or equal to 10%, better 5% of the width of said line of interlaced images.
As a variant, at least two interlaced image lines are of different widths.
The interlaced image lines have, preferably, the same general shape, stated otherwise, the edges of the interlaced image lines are mutually parallel. The interlaced image lines may be rectilinear, or not, for example curved, undulated or crenellated.
The combined image or each combined-image block may exhibit a resolution of greater than or equal to 800 dpi. Stated otherwise, it requires for its production other means of printing or of manufacture capable of producing details corresponding to such a resolution.
The combined image or each combined-image block may be as such, that is to say on being observed directly without involving the revealing raster, of homogeneous aspect to the naked eye and at a normal observation distance having regard to its fineness. In particular, the combined image may appear to the naked eye and at a normal observation distance as having a uniform aspect, especially color. This makes it possible if so desired, to have revealed images which exhibit a homogeneous aspect to the naked eye and at a normal observation distance.
By “normal observation distance” is meant the customary distance of observation of a secure item, for example 30 cm and preferably 15 cm.
In the case of interlaced images of various colors, the combined image and the revealing raster may be disposed in such a way that the revealed images each appear of solid color.
The combined image and/or each combined-image block may exhibit any suitable contour, and especially its contour may define a pattern which is situated elsewhere on the item; the combined image is for example of contour defining a pattern such as a person, animal, plant, monument or alphanumeric sign, which appears elsewhere on the item, for example in the form of a printing or of a watermark.
Revealing Raster
Preferably, the revealing raster or each revealing raster block (hereinafter “raster block”) comprises a periodic alternation of two raster elements in one or more directions.
Preferably, the revealing raster or each raster block comprises at least four raster elements, more preferentially at least six.
As a variant the revealing raster or each raster block comprises a periodic alternation of at least three raster elements. In particular a revealing raster or a raster block comprising a periodic alternation of an infinity of raster elements forms a periodic gradation.
The raster elements are, preferably, of different opacities, transparencies and/or hues, in particular one raster element is opaque and the other element is at least partially transparent. For example, each block is formed of a periodic alternation of occulting elements, for example black substantially opaque and of non-occulting elements, for example transparent, otherwise called line spacings. Therefore, when the revealing raster and the combined image are superposed, the occulting elements prevent the observation of a part of the combined image and the non-occulting elements unveil the remainder of the combined image.
As a variant, the occulting raster element is a filter which is such that when it is superposed with the combined image, the combined-image parts with which it is superposed are not visible. For example, the revealing raster is a colored filter not allowing through any of the colors of the combined image.
For one and the same dimension in a direction of the elements of interlaced images, a revealed image obtained by a revealing raster or a raster block exhibiting occulting raster elements of small dimension comprises a larger proportion of interlaced images, especially of colors, than a revealed image obtained with a revealing raster or a raster block exhibiting occulting raster elements of larger dimension.
The revealing raster comprises occulting raster elements and non-occulting raster elements.
The occulting elements afford a visual contrast with the non-occulting elements. The boundary between an occulting element and a non-occulting element is thus determined by the fact of being able or not being able to observe the effect sought, by superposition with the combined image.
This observation may be done through the non-occulting elements. As a variant, the combined image is situated between the revealing raster and the observer, and the occulting elements prevent the observer from discerning the occulting elements of the interlaced image which are superposed with it. In examples, the non-occulting element is perfectly transparent or of a sufficiently low uniform opacity or else of a sufficiently bright hue to make it possible to observe through it or on it the element or elements of interlaced images leading to the effect sought. In this case, the dimension in a direction of the non-occulting element corresponds to the width in this direction of the perfectly transparent region or region of sufficiently low uniform opacity or of sufficiently bright hue. In these examples, the transition between an occulting element and a non-occulting element is stark. In other examples, the occulting element and/or the non-occulting element forms (form) a gradation. In this case the limit of the non-occulting element in a direction, useful for determining its dimension in this direction, is that on the basis of which the opacity is sufficiently high or the hue sufficiently dark to avoid seeing the effect sought through or on the element. For example, in the case where the transition between an occulting element and a non-occulting element occurs with a continuous gradation of gray of opacity varying in a direction between Opmin and Opmax, and when, beyond an opacity Opocc, it is no longer possible to see the effect sought through the element, the dimension of the non-occulting element is given by the dimension in this direction of the region of the element where the opacity is less than or equal to Opocc.
Preferably, the revealing raster comprises a finite number of raster elements. Preferably still, the raster elements do not exhibit any gradation.
Preferably still, the non-occulting elements are each of uniform opacity or luminosity (L* in the CIE94 (L*, a*, b*) system), which may be zero, respectively low, and the occulting elements are also preferably of uniform opacity or luminosity.
The revealing raster or each block may comprise at least 5 occulting raster elements in the or each of its directions.
For example, the revealing raster or each raster block comprises a periodic alternation of two raster lines of mutually parallel longitudinal axes. Preferably, the two raster lines have parallel longitudinal axes and define a general orientation of the revealing raster or of the block.
Preferably, each raster line is of constant width over the whole of its length, its longitudinal edges being mutually parallel. The occulting raster lines and the non-occulting raster lines which alternate with one another may or may not be of the same width.
Preferably, the two raster lines have the same general shape, especially the same general shape as the interlaced image lines.
The two raster lines are, preferably, rectilinear, but as a variant the revealing raster comprises raster lines which are not rectilinear, being for example curved, undulated or crenellated.
Preferably, the edges of one of the raster lines are parallel to the edges of the other of the raster lines.
The resolution of the revealing raster is, preferably, greater than or equal to 800 dpi.
The revealing raster may be as such of homogeneous aspect to the naked eye and at a normal observation distance, having regard to its fineness. In particular, the revealing raster may appear observed with the naked eye at a normal observation distance and in white light as having a uniform aspect, especially color.
The revealing raster may exhibit a contour of any shape, for example circular, oval, disk section, star, polygonal, for example rectangular, square, triangular, hexagonal, pentagonal or lozenge-shaped, or form a more complex pattern, especially a pattern representing a text, an alphanumeric sign, an ideogram, an object, a person, a plant, a monument and/or an animal.
The revealing raster may comprise an inclusion of another security means, especially of another revealing raster.
Raster Block and/or Combined-Image Mock
The revealing raster may comprise a plurality of raster blocks, the combined image comprising a single combined-image block and being composed of a plurality of interlaced images.
As a variant, the revealing raster comprises a single raster block and the combined image exhibits a plurality of combined-image blocks, each combined-image block being composed of a plurality of interlaced images.
As a further variant, the revealing raster and the combined image may each be formed of several blocks, each combined-image block being composed of a plurality of interlaced images.
Said at least two blocks of first optical structure preferentially have the same general orientation or the same general orientations.
Advantageously, when the revealing raster and the combined image are superposed, the raster and the combined image have the same general orientation or the same general orientations. Therefore, when the revealing raster and the combined image are superposed, the raster elements are superposed with the elements of interlaced images of the combined image; the occulting raster elements prevent the observation of a part of the elements of interlaced images of the combined image, and the elements of non-hidden interlaced images form the revealed images.
Said at least two blocks of first optical structure, better all the blocks of first optical structure, are preferentially of the same period, especially in the direction or directions.
In the case where the first optical structure comprises a periodic alternation in one or more directions, said at least two blocks of first optical structure may comprise corresponding raster or combined-image elements of different dimensions and/or be mutually phase-shifted in one of their directions, by a phase shift distance dij of less than the period of the blocks of first optical structure in this direction, the phase shift distance dij being the remainder of the division of the distance in said direction between
Preferably, the period of the revealing raster or of each of the raster blocks in a direction is substantially equal to the period of the combined image or of each of the combined-image blocks in at least one of these directions.
When the raster elements and combined-image elements are lines, said at least two blocks of first optical structure preferentially have the same general block orientation, and preferably the raster lines or combined-image lines of these blocks have parallel longitudinal axes. Advantageously, all the blocks of one and the same first optical structure have the same general orientation and define a general orientation of the first optical structure.
Each of the blocks of first optical structure may comprise a larger dimension of between 1.4 mm and 42 mm.
Each of the blocks of first optical structure may represent less than 90% of the total area of the first optical structure and more than 0.2% of the latter.
Said at least two blocks of first optical structure may be arranged in distinct regions of the first optical structure. Said at least two blocks of first optical structure exhibit, preferably, a part of their contours in common.
As a variant, when the first optical structure is the revealing raster, said at least two blocks of the revealing raster are arranged in regions of the revealing raster that are partially superposed. The superposition region defines a sub-block having the shape of a new raster. The raster of the sub-block may exhibit in some exemplary implementations
Each block of first optical structure may exhibit a contour of any shape, for example circular, oval, disk section, star, polygonal, for example rectangular, square, triangular, hexagonal, pentagonal or lozenge-shaped, or form a more complex pattern, especially a pattern representing a text, an alphanumeric sign, an ideogram, an object, a person, a plant, a monument and/or an animal.
All the blocks of first optical structure may exhibit a contour of like shape; as a variant the blocks exhibit contours of different shapes.
In the case where the revealing raster comprises blocks, the area and/or the length and/or the width and/or the largest dimension, of the revealing raster may be respectively less than or equal to the area and/or the length and/or the width and/or the largest dimension, of the combined image. In this way, it is possible to simultaneously view the images revealed by all the blocks and the user may immediately compare these revealed images with one another to conclude as to the authenticity of the item.
As a variant, in the case where the combined image comprises blocks, the area, the length and/or the width and/or the largest dimension, of the combined image may be respectively less than or equal to the area, the length and/or the width and/or the largest dimension, of the revealing raster. In this way, it is possible to simultaneously view the images revealed by the revealing raster and the user may immediately compare these revealed images with one another to conclude as to the authenticity of the item.
The revealed images are observable in reflected light and/or in transmitted light, and preferably they are observable at one and the same time in reflected light and in transmitted light.
Advantageously, the revealed images exhibit a homogeneous aspect to the naked eye and at a normal observation distance, especially a homogeneous color.
The revealed images are, preferably, observable at one and the same time on the revealing raster side and on the combined image side.
Preferably, the revealed images exhibit different aspects, especially different colors and/or brightnesses.
At least one revealed image may consist of at least two adjacent interlaced images.
As a variant, at least one revealed image may comprise a single interlaced image.
Preferably, the revealed images form a macropattern when the revealing raster is superposed with the combined image, under given observation conditions. Preferably, this macropattern is visible when the orientation of the revealing raster is the same as that of the combined image.
The macropattern may change aspect upon a change of the position of the revealing raster with respect to the combined image, especially upon a displacement in one of the directions of the combined image, and/or a change of the angle of observation. For example, in the case of a combined image or of combined-image blocks formed of interlaced images of various colors, the pattern may change color. This change of aspect may give an impression of motion. For example, in the case of a revealed image of a certain color, the user may have the impression, by changing the position of the revealing raster with respect to the combined image, that the color block moves from one raster block to another.
The macropattern may disappear upon a change of the orientation of the revealing raster with respect to that of the combined image, especially when the orientation of the raster becomes different from that of the combined image.
The macropattern formed may be of any form, especially represent a text, an alphanumeric sign, an ideogram, a geometric shape, an object, a person and/or an animal.
The secure item or the assembly may comprise a second revealing raster separated from the first revealing raster and intended to be superposed with the same combined image.
As a variant, the combined image or each combined-image block may be formed of a periodic alternation of pixels of interlaced images in two non-parallel directions, especially separated by an angle of 60° or of 90°, preferably perpendicular.
By “pixels” is meant an elementary pattern. A pixel may be of polygonal shape, especially triangle, hexagon, rectangle or square.
The revealing raster or each raster block may be formed of a periodic alternation of occulting raster pixels and of non-occulting gaps in the same two directions and with the same periods in the two directions. Thus, the occulting raster pixels prevent the observation of a part of the pixels of interlaced images unveiling only a certain proportion of each interlaced image for each revealed image.
As a variant, when the combined image or each combined-image block is formed of a periodic alternation of pixels of interlaced images in two non-parallel directions, the associated revealing raster or each associated raster block may be simplified by defining a periodic alternation of occulting raster elements and of non-occulting raster elements in the form of lines.
Observation
The combined image and/or the revealing raster may be carried on the secure item or the other object by a printing method, especially offset, copper-plate, laser, heliogravure, typography or silk-screen printing, the combined image and/or the revealing raster being printed with opaque, fluorescent, translucent and/or transparent, colored or non-colored inks, visible with the naked eye, under ultraviolet (UV) and/or infrared (IR) light.
The combined image may be printed especially by a combination of colors exhibiting sufficient respective colorimetric disparities, for example printing with CMYB (Cyan, Magenta, Yellow, Black) and preferably with RGB (Red, Green, Blue).
Advantageously, metallizations and/or demetallizations are used to avoid forgery by printing.
Thus, the combined image and/or the revealing raster may comprise metallizations and/or demetallizations, for example of different metals, especially copper or aluminum and their alloys.
The at least of the combined image and of the revealing raster may feature on an at least partially transparent region of the secure item, the superposition of the revealing raster and of the combined image being performed by folding the secure item or by superposing the secure item with the other object. Each of said at least two blocks may make it possible, when superposed at least partially with the combined image of the secure item or of the other object, to observe different revealed images by a relative displacement of the revealing raster with respect to the combined image. For example, in the case where the combined image is formed of interlaced images of different colors, one of the blocks may allow, when it is superposed with the combined image so that they have the same orientation, the observation of a certain color and said color may change upon a change of the angle of observation and/or when the revealing raster is displaced in the or one of the directions of the combined image and of the revealing raster, especially perpendicularly to the longitudinal axes of the raster lines of the block and of the interlaced image lines.
The folding of the secure item may be done along a mid-line of the item, preferably parallel to a side of the item, for example along a mid-line passing through the middle of the length of the item.
The combined image and/or the revealing raster may be printed with liquid crystals and be carried on a region of the secure item or of the object polarizing the light in such a way that the combined image and/or the revealing raster are visible only upon folding the item on itself or upon superposing the secure item with the other object.
The revealing raster and the combined image may be superposed while being separated from one another by a gap of constant thickness. This gap may be formed by a transparent or translucent substrate exhibiting on the side of a first face of the substrate the combined image and on the side of a second face of the substrate, opposite to the first face, the revealing raster superposed with the combined image. Each of said at least two blocks may then make it possible to observe different revealed images, through a parallax effect, upon a change of the direction of observation of the secure item. The gap between the revealing raster and the combined image is, preferably, greater than or equal to the period of the revealing raster, especially lying between 10 μm and 1 mm, being for example less than 25 μm.
The substrate may comprise or consist of a thermoplastic substance, for example a polyolefin, for example polyethylene (PE), polyvinyl chloride (PVC), polyester, polyethylene terephthalate (PET), polycarbonate (PC), polyester carbonate (PEC), polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS) or a light-collecting film for example of the “waveguide” type, for example a luminescent film based on polycarbonate marketed by the company BAYER under the name LYSA®.
The substrate may comprise cellulose fibers and especially paper. In particular, the substrate may be a paper which is sufficiently translucent to make it possible to reveal the interlaced images, especially a tracing paper.
The substrate may or may not also be locally transparentized, by watermarking such as described in patent EP 1252389 or by applying a generally fatty composition which transparentizes it in a permanent manner, for example a composition made of oil and of transparent mineral material, as described in patent U.S. Pat. No. 2,021,141, or for example a composition in the form of a wax combined with a solvent.
It is also possible to transparentize the substrate by locally applying a wax by hot transfer, as described in patent U.S. Pat. No. 5,118,526.
It is further possible to use for the substrate a fibrous layer comprising a thermofusible substance, for example polyethylene, as described in patent EP 0 203 499, which under the local action of heat will have its transparency varied.
Secure Item
The secure item may be at least partially made of paper or plastic, in particular may comprise a rolled or extruded plastic sheet.
The secure item may comprise at least one ply of paper, especially based on natural and/or synthetic fibers, for example cotton or linen fibers in the case of a banknote.
The secure item may be at least partially transparent, opaque or translucent, especially opaque in reflected light and translucent in transmitted light.
The combined image and/or the revealing raster may be carried by a film, a lamination band, a patch and/or a foil featuring on the secure item. The film, the lamination band, the patch and/or the foil may comprise metallizations and/or demetallizations, for example of aluminum or copper, or all types of printings.
By “patch” is meant an element of smaller dimensions than that of the secure item and which might not extend as far as the edge of the item. The patch may exhibit a polygonal, circular, oval contour or one forming a more complex pattern, especially a pattern representing a text, an alphanumeric sign, an ideogram, an object, a person, a plant, a monument and/or an animal.
By “foil” or “lamination band” is meant an element applied, in particular hot, for example by transfer onto the secure item in particular from a carrier structure.
The film, the lamination band, the patch and/or the foil may comprise holographic prints and/or liquid crystals.
The combined image and/or the revealing raster may further be carried by a security thread, incorporated at the surface, bulk-wise or preferably as window(s) in the secure item.
The combined image and/or the revealing raster may be incorporated window-fashion in the secure item.
The window may be formed on the secure item during its manufacture.
The window may be formed by a material void, for example the local absence of paper, above or below the combined image and/or the revealing raster, the window preferably being at least partially transparent or translucent on the side of the combined image and/or of the revealing raster opposite to the material void.
The window may also not comprise any material void. The window may for example be at least partially transparent or translucent above or below the combined image and/or the revealing raster, the transparent or translucent regions being superposed one with the other in such a way as to be able to observe the two opposite sides of the secure item.
The window may also be a through-window. The window may exhibit superposed material voids on either side of the revealing raster and/or of the combined image. Two sides of the combined image and/or of the revealing raster may thus be observable directly and not through transparent or translucent regions. The security raster and/or the combined image may be incorporated totally in the window or partially.
The item may further exhibit a plurality of windows such as described hereinabove. The windows may or may not all be of the same type. Exemplary embodiments of windows in secure items are for example given in GB 1 552 853 which discloses the creation of a window especially by transparentization, laser cutting, mechanical incision or abrasion, EP 0 229 645 which describes the creation with the aid of masks of a window on one face or on both faces of a two-ply paper, WO 2004/096482 which describes the creation of a window by laser cutting, CA 2 471 379 which describes the creation of a transparent window and association with a security element and WO 2008/006983 which describes the creation of a transparent window on a two-ply paper.
The secure item may further comprise a security thread exhibiting the combined image and/or the revealing raster, especially a succession of combined images and/or of revealing rasters.
The secure item may further comprise two security threads, the one carrying at least one combined image and the other carrying at least one corresponding revealing raster. The security thread or threads may exhibit a sufficient width to enable the combined image and/or the revealing raster to be made to feature therein in full. The width of the security thread or threads is preferably between 3 and 20 mm, more preferentially between 4 and 10 mm and for example equal to 6 mm.
As indicated above, the revealing raster and/or the combined image advantageously feature on an at least partially transparent region of the item, in particular the revealing raster and/or the combined image may be at least partially transparent.
The at least partially transparent region may correspond to a recess, passing right through or not, of the item in which the revealing raster and/or the combined image is placed.
The region consists for example of a translucent tracing paper.
The region may further consist of a polymer layer comprising for example polyethylene (PE), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polycarbonate (PC), polyester carbonate (PEC), polyethylene terephthalate glycol (PETG), acrylonitrile butadiene styrene (ABS) or a light-collecting film for example of the “waveguide” type, for example a luminescent film based on polycarbonate marketed by the company BAYER under the name LYSA®.
The secure item, as well as the elements that it comprises such as for example a security thread, a patch and/or a foil, may comprise one or more additional security elements such as defined hereinafter.
Among these additional security elements, some are detectable by eye, in daylight or in artificial light, without using a particular apparatus. These security elements comprise for example colored fibers or slivers, totally or partially metallized or printed threads. These security elements are termed first level.
Other types of security elements are delectable only with the aid of a relatively simple apparatus, such as a lamp emitting in the ultraviolet (UV) or the infrared (IR). These security elements comprise for example fibers, slivers, bands, threads or particles. These security elements may or may not be visible with the naked eye, being for example luminescent under a lighting of a Wood lamp emitting at a wavelength of 365 nm. These security elements are termed second level.
Other types of security elements further require for their detection a more sophisticated detection apparatus. These security elements are for example capable of generating a specific signal when they are subjected, simultaneously or not, to one or more sources of exterior excitation. The automatic detection of the signal makes it possible to authenticate, if relevant, the item. These security elements comprise for example tracers taking the form of active substances, of particles or of fibers, capable of generating a specific signal when these tracers are subjected to an optronic, electrical, magnetic or electromagnetic excitation. These security elements are termed third level.
The additional security elements present within the secure item may exhibit security characteristics of first, second or third level.
The secure item may be a payment means, such as a banknote, a check, a bank card or a restaurant voucher, an identity document such as an identity card or a visa or a passport or a driver's license, a lottery ticket, a secure card, a transport pass or else an entry ticket to cultural or sports shows.
Imager
As a variant, the other object is an electronic imager making it possible to form a first image so as to be able to superpose it with a second image present on the secure item, the first image being one of the first optical structure and of the second optical structure and the second image being the other of the first optical structure and of the second optical structure
By “electronic imager” is meant an electronic device making it possible to produce an image by display or projection.
The electronic imager may comprise a screen on which the first image is displayed.
The electronic imager may comprise a screen of any known type, for example a screen of a computer, of a television, of a mobile telephone, of an electronic book or diary, of a personal digital assistant, of a digital tablet, of a watch dial, this list being nonlimiting.
The electronic imager may be a projector, with or without a screen on which the projection is performed. The projector may make it possible to project the first image onto a background or onto the security item.
The electronic imager may be a projector of any known type, for example a slide projector, a video projector, a backprojector, a picoprojector or nanoprojector, for example a miniaturized video projector integrated into a portable apparatus (PDA, mobile telephone, laptop computer, for example), a cinematographic projector, this list being nonlimiting.
The electronic imager preferably makes it possible to generate a pixellated image, each pixel of which is individually addressable, preferably with at least 256 gray levels or colors, and/or with a resolution of between 50 and 1000 dpi (“Dots Per Inch”).
The electronic imager may be a projector projecting a visible, infrared (IR) and/or ultraviolet (UV) light.
The electronic imager may comprise a screen of the LCD (“Liquid Crystal Display”), LED (“Light Emitting Diode”), OLED (“Organic Light Emitting Diode”), laser, plasma, electrochromic, FED (“Field Emission Display”), SED (“Surface-conduction Electron-emitter Display”), LCOS (“Liquid Crystal On Silicon”) type or else a cathode ray tube.
The electronic imager preferably comprises a liquid crystal screen (LCD).
The screen may exhibit a resolution of between 50 and 600 dpi, better between 100 and 300 dpi, for example equal to 160 dpi.
The second image may feature on a region of reduced opacity of the secure item. Such a region of reduced opacity may in particular correspond to a region of lesser thickness, to a region rendered transparent or to a region comprising at least one layer of a material of lesser opacity. The opacity of said region of reduced opacity will in particular be sufficiently low to allow observation in transmission of the first image. Preferably, the second image is visible in transmission and in reflection.
The second image may feature on an at least partially transparent or translucent region of the secure item.
When the electronic imager produces the first image by means of a polarized light, the second image features preferably on an at least partially transparent or translucent region, especially an at least partially transparent window.
The first image produced by the electronic imager may be displayed on the electronic imager, for example on a screen of the electronic imager.
As a variant, the first image is projected by the electronic imager, for example onto a background or onto the secure item. In particular, when the first image is projected onto a background, the second image of the secure item may be superposed with the first image projected onto the background. As a variant, the first image is at least partially projected on the second image of the secure item.
The item and the imager may or may not come into contact when the images are superposed.
The first image and/or the second image may exhibit polarization properties.
For example, the first image is produced by the electronic imager by means of polarized light, especially rectilinearly, circularly or elliptically polarized light. The electronic imager may comprise a screen emitting polarized light or may project polarized light.
The secure item may comprise a polarizing filter. In particular, the second image may be produced with the aid of a polarizing filter.
The second image may be produced according to at least one of the following steps:
By way of remark, according to the desired effect, the above-stated steps will be carried out so as to form an image which is the image in positive or in negative of the second image. In particular, a polyether base aliphatic polyurethane, for example such as that marketed by the company LAMBERTI under the name Esacote® PU 21/S, can be applied locally to at least one polarizing filter, for example by printing.
In the last possibility mentioned hereinabove, when during the implementation of the method according to the invention, the composition comprising cholesteric liquid crystals is situated between the polarizing substrate and the electronic imager, the cholesteric liquid crystals modify the electronic imager's polarized light which is not stopped by the substrate and the regions covered with cholesteric liquid crystals appear transparent when the polarizing substrate is oriented in such a way as to be opaque.
On the other hand, when the polarizing substrate is situated 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 oriented in such a way as to be opaque. The optically variable effect of the cholesteric liquid crystals is more generally known by the term “colorshift” effect, the color of the cholesteric liquid crystals depending on the angle of observation and the latter being in particular observed on a dark background, preferably black in color. The “colorshift” effect of the cholesteric liquid crystals may constitute an additional security to authenticate and/or identify the secure item.
Thus, in particularly preferred exemplary implementations of the method according to the invention, the second image is defined by a first polarizing material superposed on a second polarizing material, the first material extending in particular according to patterns corresponding to the second image and the second material extending in a continuous manner. The first material is preferably a printing of cholesteric liquid crystals and the second material is preferably a linearly polarizing substrate.
By “patterns corresponding to the second image” is meant that said patterns form the second image in negative or in positive.
Advantageously, when the first and second images exhibit polarization properties, there exists only a single orientation of one with respect to the other allowing one to partially mask the other. Stated otherwise, there exists only a single orientation of the first image with respect to the second image making it possible not to be able to observe the first image through the polarizing regions of the second image, or vice versa. Indeed, the first and second images exhibiting polarization properties consist of polarizing regions and of non-polarizing regions. When they are placed in front of a luminous source emitting polarized light, there exists only a single orientation according to which the polarizing regions become opaque.
In particular, in the case where the item comprises a polarizing filter there exists for example only a single orientation of the second image with respect to the first image projected or displayed by the electronic imager by means of a polarized light, which allows the polarizing filter to mask the polarized light of the electronic imager. The polarizing filter may appear opaque, especially black in color, only in this, preferably unique, orientation of the first image with respect to the second image.
The presence of a unique orientation, such as described hereinabove, of the first and second images with respect to one another may make it possible to authenticate and/or to identify the secure item according to a first security level.
The electronic imager, for example the screen of the electronic imager, and/or the secure item, may comprise an indicator making it possible to advise the user on the way of positioning the first and second images with respect to one another to obtain said orientation, for example a visual reference marker.
According to a variant embodiment, the second image is printed with a compound, especially liquid crystals, which is visible only when placed in front of an electronic imager emitting polarized light, especially a liquid crystal screen. Advantageously, the second image is transparent under unpolarized illumination, for example under natural lighting, and is visible only under polarized illumination with the aid of the electronic imager, thereby affording the secure item an additional security.
The secure item may comprise an integrated microcircuit, for example an RFID chip or an optical chip (activated for example by the light issuing from the electronic imager), able to communicate with the electronic imager so that the latter produces, in particular displays and/or projects, a piece of information advising as regards the way of positioning the first and second images with respect to one another to obtain said orientation.
The secure item may comprise an integrated microcircuit, for example an RFID chip or an optical chip, able to communicate with the electronic imager so that the latter produces at least one first image whose association with the second image makes it possible to implement the method according to the invention. In particular, the electronic imager may produce at least one first image associated with a second image of the secure item by communication between the electronic imager and the integrated microcircuit.
The electronic imager may further produce at least one first image on the basis of a photo and/or of a video of the secure item, especially of the second image of the secure item or of an identifier present on the item, for example a logo or a serial number. The photo and/or video may be produced with the electronic imager, an image capture device, for example a digital camera, connected to the electronic imager by a wired or non-wired link and/or be transferred to the electronic imager, for example from a data storage device or via a network, such as the Internet.
The first image may be produced solely on the basis of the photo and/or video of the secure item, or as a variant, be produced on the basis of the photo and/or video of the secure item and of an additional piece of information, for example a piece of information present on the secure item, on the photo and/or video, input by the user, or else received from a network, for example of a secure server.
The electronic imager may comprise a program making it possible to identify the secure item, and especially the second image, and to produce, especially to display and/or to project, a first image obtained from a database advising as regards the first image to be used as a function of the secure item, especially of the second image.
The electronic imager may produce several first images and/or the secure item may comprise several second images, at least one of the first images making it possible to observe the authentication and/or identification piece of information when superposed with at least one of the second images according to the method of the invention, or vice versa.
In particular, it may thus be possible to authenticate and/or to identify the security item with various types of electronic imagers.
As a variant, a given electronic imager may make it possible to authenticate and/or to identify secure items of various types, comprising in particular different second images.
For example, the second images are differentiated by their size, their color, their shape, or indeed by the spacing between the raster elements or interlaced-image elements or the width of the latter.
The first images may also be differentiated by their size, their color, their shape, or indeed by the spacing between the raster elements or interlaced-image elements or the width of the latter, or else indeed by the size of the pixels, the spacing between the pixels or the color of the pixels.
The electronic imagers may for example be differentiated on account of their brand, their model, their resolution, their type, namely computer screen, television screen or telephone screen, or projector, for example.
The presence of several first images and/or second images may make it possible to authenticate and/or to identify the security item independently of the differences mentioned hereinabove.
The first image produced by the electronic imager may originate from a communication network with which the electronic imager communicates, for example a telephone network, Internet or an internal network, the image being for example downloaded, and/or be provided together with the electronic imager, for example on a data medium, for example a hard disk, a USB key, a CD and/or a DVD. The security item may, if relevant, comprise such a data medium. The data medium may be an integrated microcircuit, for example an RFID or optical chip, communicating with the electronic imager.
The secure item may comprise a luminescent region, for example fluorescent and/or phosphorescent, and the electronic imager may project the first image onto the secure item under ultraviolet (UV) lighting.
In particular, the second image may be a luminescent print, for example carried out on a black opaque background of the secure item, and onto which the first image is projected under UV lighting. The second image is then visible only under UV lighting.
The second image may further be printed on a luminescent background of the secure item, so that it is visible at one and the same time under UV lighting and normal lighting.
Two Revealing Rasters
A further subject of the invention is, according to a second aspect, a secure item comprising a first and a second first optical structure and a second optical structure, or an assembly comprising a secure item and another object, the secure item comprising one of first and second first optical structure and of a second optical structure and the object comprising or forming the other of first and second first optical structure and of a second optical structure,
the first and the second orientation being different
The fact of having two first optical structures that are superposed with the same second optical structure makes it possible, by varying the orientation of the first optical structures with respect to the second optical structure, to observe at the level of the blocks the first or the second revealed images, thereby affording an additional security.
Thus, when the first optical structure is a revealing raster, a subject of the invention is, according to this second aspect, a secure item comprising a first and a second revealing raster and a combined image, or an assembly comprising a secure item and another object, the secure item comprising one of the first and second revealing rasters and of the combined image and the object comprising or forming the other of the first and second revealing rasters and of the combined image,
Thus, when the first optical structure is a combined image, a subject of the invention is, according to this second aspect, a secure item comprising a first and a second combined images and a revealing raster, or an assembly comprising a secure item and another object, the secure item comprising one of the first and second combined images and of the revealing raster and the object comprising or forming the other of the first and second combined images and of the revealing raster,
when the revealing rasters and the combined image are superposed, at a position of the revealing raster with respect to the combined image and an angle of observation,
the first and the second orientation being different.
The combined optical structure or structures, the revealing raster or rasters, the secure item and the object may be such as described hereinabove.
Preferably the two first optical structures have different general orientations.
The first revealed images may form a first pattern in the first orientation and the second revealed images form a second pattern in the second orientation, the first pattern not being visible in the second orientation and the second pattern not being visible in the first orientation.
Preferably, in the first orientation, the superposition of the second first optical structure with the second optical structure forms a Moiré effect and/or in the second orientation, the superposition of the first optical structure with the second optical structure forms a Moiré effect.
Preferably, in the first orientation, the general orientation of the first optical structure is the same as the general orientation of the second optical structure and in the second orientation, the general orientation of the second first optical structure is the same as the general orientation of the second optical structure.
The first and the second orientation may form an angle β of between 0 and 180° bounds excluded, better between 10 and 30°.
Method
A further subject of the invention is a method for authenticating a secure item according to the first and the second aspects of the invention, in which the images revealed by the blocks of the revealing raster or rasters and/or of the combined image or images are observed and one concludes as to the authenticity of the item at least on the basis of this observation.
It is also possible to change the angle of observation and/or the position of the revealing raster with respect to the combined image so as to observe a change of the revealed image for each block and thus conclude as to the authenticity of the item at least on the basis of this observation.
In the case where the combined image and the revealing raster or rasters are not superposed within the item, it is possible to superpose the revealing raster at least partially with the combined image so as to observe the images revealed by the various blocks by folding the secure item and/or by superposing the secure item and the other object and one concludes as to the authenticity of the item at least on the basis of this observation.
When the secure item comprises several revealing rasters or several combined images, it is also possible to change the orientation between the revealing raster or rasters and the combined image or images so as to observe the revealed images and thus conclude as to the authenticity of the item at least on the basis of this observation.
When one of the revealing raster and of the combined image is formed by an electronic imager, the method may comprise at least one of the following steps:
The photo and/or video may be produced with the electronic imager, an image capture device, for example a digital camera, connected to the object and/or be transferred to the electronic imager, for example from a data storage device or via a network, such as the Internet.
The invention will be able to be better understood on reading the detailed description which will follow, of nonlimiting exemplary implementations of the latter, and on examining the appended drawing in which:
Combined Image
Illustrated in
The interlaced image lines ii have parallel longitudinal axes defining a general orientation Oi of the image combined by their general direction. The periodicity is observed along an axis XI perpendicular to the longitudinal axis of the interlaced image lines.
The lines of an interlaced image are continuous and of like length, but it may be otherwise.
The combined image I corresponds to the superposition of these interlaced images I1 to In while shifting them with respect to one another along the axis XI so that the interlaced image lines i1 to in are not superposed between the various images.
The widths l1 to ln of the lines of the interlaced images i1 to in are such that the sum of the widths l1 to ln of these lines l1 to in is less than or equal to the period S, and preferably, equal to the period S:
In the example illustrated, the lines of an interlaced image i1 to i3 are of like width l1 to l3 equal to S/3.
As a variant, the lines i1 to in of the interlaced images may be of widths l1 to ln that differ with respect to one another, such as represented in
In the example of
The period S is between 10 μm and 1 mm, preferably between 50 and 200 μm.
The width l of the lines of the interlaced images i1 to in is less than or equal to 50 μm, being for example substantially equal to 33 μm. This value corresponds to a resolution of the combined image I of about 800 dpi, this representing a limit for conventional printers which generally have a maximum definition of 600 dpi, and which constitutes a security factor.
Moreover, the human eye not perceiving, at an observation distance of greater than or equal to 30 cm, details of less than approximately 100 μm, a sufficiently fine combined image appears of homogeneous aspect, for example substantially white here in transmitted light.
Hence, whatever the color or colors used for the combined image, the printing definition may be precise enough for the mixture of the colors to appear as homogeneous.
As a further variant illustrated in
In the example illustrated in
The combined image I may be formed by printing, especially by four-color printing.
As a variant, the combined image I is formed by metallization and/or demetallization, especially by metallization with the aid of metals of different colors for each of the interlaced images I1 to In. For example, the combined image I comprises two interlaced images I1 and I2, one being made of copper and the other of aluminum.
The interlaced images I1 to In may be glossy or matt. For example, the interlaced images are at least differentiated partially by their glossiness, some interlaced images being matt and other interlaced images being glossy.
As will be described hereinafter, the combined image I may also be formed by an electronic imager 100.
Revealing Raster
In the example illustrated in
The longitudinal axes of the raster lines 5a and 5b define a general orientation of the raster Ot by their general direction.
The opaque raster lines 5a are of a constant width m which is less than the period Q of the raster and the transparent raster lines 5b are of a constant width k which is less than the period Q.
The widths of the opaque raster lines 5a and of the transparent raster lines 5b may or may not be identical.
In the example illustrated, the raster lines 5a and 5b have rectilinear and parallel edges, but it may be otherwise. The revealing raster 4 may comprise other patterns such as crenellations or undulations, such as is illustrated respectively in
The resolution of the revealing raster 4 is, preferably, greater than or equal to 800 dpi.
The revealing raster 4 may be as such of homogeneous aspect to the naked eye and at a normal observation distance, having regard to its fineness. In particular, the revealing raster may appear to the naked eye at 15 cm distance as having a uniform, gray color, which is darker or lighter according to the width m of the opaque raster line 5a.
A sufficiently fine combined image and a sufficiently fine revealing raster make it possible to afford anti-photocopy security.
The combined image I and/or the revealing raster 4 may be formed by printing, metallization, demetallization, laser marking, lithography or any other technique making it possible to fix or unveil an image.
To improve security, it is possible to use liquid-crystal inks, for example to print the combined image I. Animation, in order to be revealed, may then require in addition to the revealing raster, the use of a polarizer filter, which may or may not be present on the item.
The revealing raster 4 may be formed by printing or metallization and/or demetallization.
The opaque raster lines 5a of the revealing raster 4 may be glossy or matt.
As a variant, the revealing raster 4 is different, especially the raster lines are not opaque and transparent. The occulting raster lines may be formed of a filter not allowing the wavelengths corresponding to the combined image to pass through and the non-occulting raster lines may allow these wavelengths to pass through at least partially.
Revealed Image
The period Q of the revealing raster 4 is equal to the period S of the combined image I.
When the revealing raster 4 and the combined image I are superposed and the general orientation Ot of the revealing raster 4 is substantially the same as the general orientation Oi of the combined image I, a revealed image Ir may be observed. The revealed image Ir then corresponds to the parts of the combined image I that are present under the transparent raster lines 5b for a given angle of observation.
Indeed, when the revealing raster 4 and the combined image I are superposed, under the condition cited previously and when the revealed images are observed on the revealing raster side, the opaque raster lines 5a mask one part of the interlaced image lines i1 to in, the other part of the interlaced image lines i1 to in being visible through the transparent raster lines 5b. The transparent raster lines 5b all allow the viewing of the same proportion (P1; . . . ; Pn) of the interlaced image lines i1 to in. The proportion Pi corresponds to the proportion of a line ii of the interlaced image Ii that is visible.
In the case where the superposition is observed on the combined image I side, the opaque raster lines 5a render the interlaced image lines i1 to in on which they are superposed dark and therefore prevent them being viewed. Thus only the interlaced image lines i1 to in superposed on the transparent raster lines 4b are visible to form the revealed image Ir.
Preferably, the revealed images Ir are observable in reflected light and in transmitted light.
In the example of
As a variant, in the example of
The revealed image Ir may appear homogeneous to the naked eye. In the case of a combined image I in the form of a colored raster formed of an alternation of red, green and blue lines of identical widths l and of a revealing raster of width of a transparent raster line k, it is possible to determine the color of the revealed image Ir in RGB coordinates on the basis of the proportion (PR, PG, PB). The RGB coordinates take the form of three numbers lying between 0 and 255 characterizing said color, each number representing the proportion of one of the components red, green and blue making it possible to obtain said color.
The components have coordinates:
R=Rmax*PR,
G=Gmax*PG, and
B=Bmax*PB,
with
R
max
=G
max
=B
max=255*k/s
It is thus possible to determine the color of the image revealed as a function of the width k of the transparent raster lines 5b and of the proportion (PR, PG, PB) of the interlaced images I1, I2 and I3. The revealed image Ir is observable in transmitted light or in reflected light at one and the same time on the revealing raster 4 side and on the combined image I side when the revealing raster 4 and the combined image I are superposed.
In the variant illustrated in
The pixels of
The preceding description, given for lines, applies to the pixels. Thus, the pixels p1 to pn belonging to different interlaced images exhibit a different aspect, especially a different hue, saturation, glossiness, transparency, luminescence. For example the pixels p1 to pn belonging to different interlaced images are of different colors, especially red, green and blue.
The combined image I exhibits a period SX in the direction XI and a period SY in the direction YI. Here, the directions XI and YI are perpendicular but it could be otherwise. The directions XI and YI could form a non-zero angle, different from 90°, between themselves.
The interlaced-image pixels p1 to pn exhibit a dimension lX and a dimension lY in respectively the directions XI and YI. The dimensions lX and lY are each such as described previously for the interlaced image lines i1 to in.
The revealing raster 4 is according to
The pixels of the revealing raster may be of a dimension mX and of a dimension mY in the respective directions XT and YT which are less than the periods SX and SY respectively.
In the example illustrated, the dimension mX in the direction XT is equal to the dimension lX of the interlaced-image pixels p1 to pn and the dimension mY in the direction YT is equal to the dimension lY of the interlaced-image pixels p1 to pn.
The dimensions mX and mY may be different respectively from lX and lY on condition that the periods in the directions X and Y are the same.
Upon superposing the revealing raster 4 and the combined image I so that the directions XT and XI coincide and that the directions YT and YI coincide, the revealing raster makes it possible to observe revealed images Ir such as are represented in
In the example illustrated the opaque raster pixels 5a hide one of the interlaced images I1 to In so that two of the interlaced images are visible. In
The various revealed images Ir illustrated may be obtained by displacing the revealing raster 4 with respect to the combined image in the direction XI, the direction YI or the direction Z and/or by changing the angle of view around the directions XI and YI or Z.
Observation of a Change of the Revealed Image
It is possible to vary the revealed image Ir observed by changing the conditions of observation of the superposed revealing raster 4 and combined image I, and especially, as is detailed hereinafter, by changing the angle of observation and/or by displacing the revealing raster 4 with respect to the combined image I. Thus, virtually or really, by displacing the combined image I with respect to the revealing raster 4 in a direction X perpendicular to the general orientation of the combined image I and of the revealing raster 4, the revealed image Ir varies.
Thus, by changing the observation conditions, it is possible to pass from
By varying the observation conditions, the user may then see a change of the revealed image Ir and conclude in view of this observation as to the authenticity of the item.
Blocks
As illustrated in
The blocks B1 to Bg of the revealing raster 4 are superposed with the same combined image I.
Preferably, as illustrated, the blocks B1 to Bg of one and the same raster are of the same period Q and of the same general orientation Ob. The general orientations Ob of the blocks 10 define a general raster orientation Ot.
The blocks B1 to Bg exhibit a maximum dimension v of between 1.4 and 42 mm and an area equaling between 0.2 and 90% of the area of the revealing raster.
In the examples illustrated in
d
ij=remainder(cij/Q)
When the revealing raster 4 is observed so that its general orientation Ot is vertical, at least one part of the opaque raster lines of a block Bi may be above and/or alongside at least one part of the opaque raster lines of another block Bj.
Thus, when the revealing raster is superposed with the combined image and exhibits the same general orientation, the transparent raster lines 5b of the block Bi do not unveil the same proportion of the interlaced images (P1; . . . ; Pn) as that of the block Bj and therefore the images revealed Iri and Irj respectively by the blocks B1 and Bj are of different aspects since they do not exhibit the same proportion (P1; . . . ; Pn) of the interlaced images. In the case illustrated of a rasterized and colored combined image, for example with red, green and blue lines, the revealed images Ir1 to Irg of the mutually phase-shifted blocks are of different colors.
Preferably, the revealing raster 4 is continuous and each of the blocks B1 to Bg exhibits a part of its contour in common with another of the blocks B1 to Bg.
The revealed images Ir1 to Irg may form a pattern, especially a text, an alphanumeric sign, an ideogram, a geometric shape, an object, a person and/or an animal, for example reproduce a pattern present elsewhere on the secure item.
By changing the conditions of observation of the superposed revealing raster 4 and combined image I, especially, as is detailed hereinafter, by changing the angle of observation and/or by displacing the revealing raster 4 with respect to the combined image I, the images revealed Ir1 to Irg by the various blocks B1 to Bg may vary. This change of aspect may give an impression of motion or may vary the color of a pattern.
In these examples, the revealing raster 4 is superposed with a combined image I formed of three interlaced images respectively colored red, green and blue, such as described previously.
In the example illustrated in
The blocks B1, B2 and B3 are mutually phase-shifted and the block B4 is not phase-shifted with respect to the block B1, the block B5 is not phase-shifted with respect to the block B2 and the block B6 is not phase-shifted with respect to the block B3 so that each of the blocks B1 to B6 is phase-shifted with respect to the blocks B1 to B6 that are adjacent to it.
As visible in
The opaque raster lines of the block B1 have a corner 9 in common with the opaque raster lines of the block B3. The same holds with the blocks B3 and B5, B2 and B4, and B4 and B6. As illustrated in
The revealed images Ir1, Ir2 and Ir3 are phase-shifted and the respective revealed images Ir1 and Ir4, Ir2 and Ir5 and Ir3 and Ir6 are identical. The revealed images Ir1 to Ir6 form a rectangle composed of 6 squares each formed by a revealed image Ir1 to Ir6, each square neighboring squares of different colors. Thus, as illustrated in
By changing the observation conditions, it is possible to pass from
In the example illustrated in
As a variant illustrated in
As a variant illustrated in
In the example illustrated in
The blocks B1, B2, B3 and B4 are mutually phase-shifted and the blocks B5, B9 and B13 are not phase-shifted with respect to the block B1, the blocks B6, B10 and B14 are not phase-shifted with respect to the block B2, the blocks B8, B12 and B15 are not phase-shifted with respect to the block B3 and the blocks B8, B12 and B16 are not phase-shifted with respect to the block B4 so that each of the blocks B1 to B16 is phase-shifted with respect to the three blocks B1 to B16 which follow it and which precede it when it is rotated clockwise.
The opaque-raster lines 5a have a width m substantially equal to three-quarters of the width l of the interlaced-image lines.
The block B1 is phase-shifted from the block B2 by a distance d12 equal to three-quarters of the width l of an interlaced image line i1 to i4, the block B1 is phase-shifted from the block B3 by a distance d13 equal to three-halves of the width l of an interlaced image line i1 to i4 and the block B1 is phase-shifted from the block B4 by a distance du equal to nine-quarters of the width l of an interlaced image line i1 to i4.
The revealed images Ir1 to Ir16 form a disk composed of 16 sectors each formed by a revealed image Ir1 to Ir16, each sector being situated between sectors of different colors. Thus, as illustrated in
Thus, by changing the observation conditions, it is possible to pass from
In the example illustrated in
The images are schematic for illustration purposes, however during the observation of the revealing raster alone illustrated in
The opaque raster lines 5a have a width m substantially equal to three-quarters of the width l of the interlaced image lines just as in the example of
The revealed images Ir1 to Ir4 form the number 100 on a colored background, the colors of all the digits being different
Thus, by changing the observation conditions, it is possible to pass from
In the variant illustrated in
In the variant illustrated in
Each sub-block 15 allows the observation of a revealed image Ir by superposition with the combined image. In the case (i), the revealed image is of the same shape as for a block having an opaque raster line of the same width and in the case of the image (ii), the revealed image obtained depends on the position and on the width of the raster lines 15a and 15b.
As a further variant, such as illustrated in
In the example of
As a variant, the combined image I illustrated in
The blocks of the combined image are each such as described in conjunction with
The combined-image blocks C1 to C3 are rectangular in shape. The blocks C1 and C2 are mutually phase-shifted by a width l of an interlaced image line and the blocks C1 and C3 are not mutually phase-shifted.
The revealing raster exhibits opaque raster lines 5a exhibiting a width m equal to the width l of a line i1 to i3 of interlaced images.
During the superposition of the revealing raster 4 and of the combined image I, such as illustrated in
By changing the observation conditions, especially by displacing the revealing raster with respect to the combined image in the direction X or by changing the angle of observation, the revealed images Ir1 to Ir3 change by passing for example from
Observation by Superposition on Either Side of a Support
Represented in
When the secure item 10 is observed from one side or from the other of the substrate, the revealing raster 4 makes it possible to observe one or more revealed images Ir. By changing the angle of observation α, the user changes the observation conditions and the revealed image or images Ir are modified as described previously.
To be able to view all the interlaced images up to an angle of inclination of about 45°, the thickness e of the substrate is, preferably, greater than or equal to approximately the period Q.
It may be advantageous to have a substrate whose thickness e is less than or equal to 30 μm, better 25 μm, for example lying between 20 and 30 μm, or indeed 20 and 25 μm, bounds included or excluded.
Another possibility for varying the direction of observation of the secure item may be to deform the substrate, for example around a fold axis, as illustrated in
As a function of the pattern of the revealing raster 4, a tagging of the latter with respect to the combined image I may be necessary in the sense parallel to their general orientation. For example, for a linear revealing raster such as illustrated in
For secure items comprising a thread introduced as window(s), the combined image I may be obtained by micro-photolithography of the thread and the revealing raster 4 may be produced with the help of offset printing with inks crosslinking under UV, performed subsequently when printing the item.
The revealing raster 4 may be associated, if relevant, with a printing pattern of the item.
The pattern of the revealing raster 4 may be printed otherwise than by superposition with the combined image I, on the item, to the same scale or to a different scale.
The printing of the revealing raster 4 may overrun the combined image I and extend over the secure item 10, as illustrated in
Several revealing rasters and combined images, having for example the form of small squares or rectangles with sides of a few millimeters, may be present in one and the same security thread 30, as illustrated in
When the revealing raster 4 and the combined image I are on a thread integrated as window(s), as illustrated in
The item may comprise at the level of the windows 31 and 32 material voids and transparent regions 35 and 36 allowing the observation of the revealed images from both sides of the secure item 10.
The interlaced images are observable through the revealing raster 4 from the window 31 side and with the revealing raster as background, from the window 32 side.
The item 10 may also comprise a through window 31, as represented in
The revealing raster 4 and the combined image in the form of a security thread may further be incorporated into a secure item 10 which exhibit an alternation of windows 31 and 32 recto side and verso side, as illustrated in
Represented in
The sub-element 41 comprises for example a revealing raster 4 and the sub-element 42 comprises for example the corresponding combined image I.
The sub-elements 41 and 42 may be at least partially superposed on the boundaries of the perforation 40 with or without a thickness compensation.
The sub-elements 41 and 42 may be at least partially transparent or translucent.
The observation of the revealed images may be done by observation in reflection or in transmission, for example with the aid of a light source situated behind the item 10 during observation.
In the variant illustrated in
The secure item 10 may or may not be opaque. The secure item 10 may be at least partially transparent or translucent to allow observation of the interlaced images, especially on the combined image I side.
In the examples of
As a variant, the combined image comprises two metallizations of various colors, each corresponding to an interlaced image, especially a copper interlaced image and an aluminum interlaced image.
As a further variant, the combined image comprises at least two metallizations, especially of the same color, of various optical densities and each corresponding to an interlaced image, thus creating a glossiness contrast.
The aluminum interlaced image may be of high optical density, thereby giving it a glossy aspect.
The revealing raster 4 may be of matt aspect.
Superposition of the combined image I and of the revealing raster 4 makes it possible to obtain according to the blocks B1 to Bg, matt or glossy revealed images Ir1 to Irg. A displacement of the revealing raster 4 with respect to the combined image I along the axis X may make it possible to invert the aspect of the revealed images Ir1 to Irg at the level of the various blocks B1 to Bg, that is to say that the revealed images Ir1 to Irg which were glossy may become matt and vice versa.
Observation by Folding the Document or Superposing the Document and Another Object
In a second embodiment, illustrated in
To observe the revealed image, the user must therefore fold the secure item 10, as illustrated in
In
The patch 55 may comprise metallizations and/or demetallizations, made for example of aluminum, and the revealing raster 4 may comprise holographic prints and/or metallizations and/or demetallizations.
In
Represented in
In
In
The security thread 60 may be at least partially transparent or exhibit an at least partially transparent region. The item 10 may also comprise an at least partially transparent region at the level of the combined image I.
In
The security thread 60a and/or the security thread 60b may be at least partially transparent or comprise at least one at least partially transparent region, especially at the level of a combined image I or of a revealing raster 4.
In
The foil 70 may be at least partially transparent or comprise at least one at least partially transparent region at the level of a combined image I and/or of a revealing raster 4.
In
The security thread 60 may be at least partially transparent or comprise an at least partially transparent region at the level of the combined image I.
The patch 55 may also be at least partially transparent, especially at the level of the revealing raster 4.
In all the examples described previously, the combined images I and the revealing rasters 4 may be swapped.
The at least partially transparent regions may be situated at the level of the combined images I or of the revelation means 4, or at the level of both at one time.
The security thread or threads 60, 60a and 60b may be introduced into the secure item 10 in a conventional manner, for example at the surface, bulk-wise or as window(s).
The authentication of the items 10 may be done by folding them 10 lengthways or widthways so as to at least partially superpose the combined images I and the revealing rasters 4, and then by displacing relative to one another so as to view for example the illusion of a motion and/or by modifying the angle of observation of the combined images I and of the revealing rasters 4 superposed.
As a further variant, it is also possible to superpose the item 10 at least partially with another similar item, such as described previously.
Two Revealing Rasters Exhibiting Blocks
As illustrated in
The two revealing rasters are, preferably, of different general orientations Ota and Otb forming between them a non-zero angle β, preferably lying between 0° and 180° bounds excluded, better between 10 and 30°, for example here substantially equal to 20°.
The fact that the revealing rasters have different general orientations allows at given observation conditions that:
Thus, according to the orientation of the combined image I with respect to the revealing rasters 4a and 4b, one or the other or none of the revealed images is visible, thereby affording the possibility of increased security.
To observe the images revealed by one or the other of the rasters, the user must therefore superpose the combined image I and the revealing rasters 4a and 4b by folding the item 10 or superposing the item 10 and another object and rotate the combined image I with respect to the revealing rasters 4a and 4b. The user may also displace them with respect to one another along an axis X perpendicular to the general orientation of the combined image to observe a change of the revealed image or images of one of the rasters.
The two revealing rasters 4a and 4b may or may not be separated from one another. Preferably, the revealing raster 4b is an inclusion in the revealing raster 4a.
In the example illustrated in
The second revealing raster 4b is of rectangular shape and it is formed of 4 blocks B1b to B4b of various shapes. The block B2b represents the digit 1, the blocks B3b and B4b represent the digit 0 and the block B1b is a rectangular block in which the other blocks are inserted. The blocks B2b to B4b are not mutually phase-shifted but are phase-shifted with respect to the block B1b.
The two revealing rasters 4a and 4b have different respective general orientations Ota, and Otb and form between them an angle β substantially equal to 20°.
The opaque raster lines 5a have a width m substantially equal to three-quarters of the width l of the interlaced image lines just as in the example of
The revealing rasters 4a and 4b are superposed with the same combined image I, illustrated in
As visible in
As visible in
As illustrated in
Imager
Represented in
In
The secure item 10 is for example in the form of a banknote and comprises a second image 120, the second image being the revealing raster 4 if the first image is the combined image and vice versa.
The secure item 10 is placed on the screen of the electronic imager 100 in such a way as to superpose the first image 110 at least partially with the second image 120 so as to observe the revealed image or images Ir and deduce therefrom an authentication and/or identification piece of information in respect of the secure item 10.
The secure item 10 may be displaced relative to the screen of the electronic imager 100 or the observer may change angle of observation to allow the observation of a change of the revealed image or images Ir.
As a variant, the secure item 10 remains immobile with respect to the screen of the electronic imager 100 and the first image 110 is animated with a motion on the screen, for example a translation, for example with the aid of a program activated or not by the user.
In
The secure item 10 comprising the second image 120 may then be at least partially superposed with the first image 110 projected onto the background 150 to allow observation of the revealed image or images Ir.
In
The first image 110 may, as in the example of
In a variant, not represented, the first image 110 is projected directly on the second image 120 of the item 10. In particular, the projection of the first image 110 on the second image 120 of the item 10 may allow an at least partial superposition of the first and second images. Next, the electronic imager 100 may be displaced relative to the item 10 so as to displace the revealing raster 4 with respect to the combined image I.
Represented in
The first images 110a to 110d may have different properties, for example different shapes, colors, dimensions, raster elements.
Advantageously, the first images 110a to 110d are differentiated in such a way as to allow one of them at least to be associated with at least one second image 120 present on an item 10. In this way, it is for example possible to authenticate and/or identify a greater diversity of items 10 having different respective second images, corresponding to the various first images 110a to 110d.
As a variant, the item 10 comprises several different second images 120, as may be seen for example in
The electronic imager 100 may display one or more indicators 140a, 140b, 140c and 140d making it possible to advise the user on the way to position the item 10 represented in
In particular, the indicators 140a to 140d may make it possible to know where to position the top right corner of the item 10, so as to correctly superpose a second image 120 of an item 10 with a first image 110a, 110b, 110c or 110d displayed on the screen of the electronic imager 100.
The item 10 may comprise an integrated microcircuit 152, for example an RFID or optical chip, making it possible to communicate with the electronic imager 100 so as to control the display of an indicator such as described previously or to disseminate a piece of information on the way to position the first and second images.
As a variant, the chip 152 is able to communicate with the electronic imager 100 so as to make it possible to produce the first image 110 associated with the second image 120.
In particular, during the method for authenticating and/or identifying the item 10, the second image 120 is illuminated with the electronic imager 100. The chip 152 comprises a piece of information transmitted to the electronic imager 100 which then projects or displays the first image 110 as a function of this piece of information.
The item 10, especially the second image 120, may be photographed and/or filmed by a digital camera belonging or linked to the electronic imager 100. A recognition program may then make it possible to recognize the second image 120 and to acquire from a database a first image 110 associated with the second image 120. The database is for example stored on a secure server. The first image 110 thus obtained is displayed and/or projected by the electronic imager 110 so as to make it possible to authenticate and/or to identify the item 10.
In the variant illustrated in
The item 10 comprising the revealing raster 4 may be displaced by a translation motion along the axis X with respect to the combined image I displayed by the screen of the electronic imager 100, in such a way as to change the revealed image or images Ir.
Such a method makes it possible to authenticate and/or to identify the security item 1 according to several security levels.
The positioning of the revealing raster 4 comprising the polarizing filter according to the orientation making it possible to observe the opacity of the polarizing filter, this observation being visible only on a screen emitting a polarized light, for example a screen of the LCD type, affords a first level of security.
The revealing of the animation of the revealed images by displacement of the revealing raster 4 relative to the combined image I affords a second level of security.
As a further variant, the electronic imager 100 is a screen, especially of the LCD type, comprising a plurality of pixels preferably forming a combined image, for example such as described in
The invention is not limited to the examples illustrated. The secure item may be produced with other securities of first, second or third level, for example.
The expression “comprising a” should be understood as being synonymous with “comprising at least one”.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1563425 | Dec 2015 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/082648 | 12/23/2016 | WO | 00 |
