FR3042735A1 - SECURITY DEVICE FOR A MATRIX THAT CAN BE CUSTOMIZED USING A LASER TO PRODUCE A COLOR IMAGE - Google Patents

Abstract

A security device comprising a matrix adapted to be personalized by means of a laser for producing a color image, comprising a color layer comprising elements, each of a single base color, and at least one laser-sensitive blackout layer, where the shape of at least one element is changed.

Description

The present invention relates to a safety device. This security device is more particularly adapted to a matrix adapted to be personalized by means of a laser to produce a color image. Such a security device secures such a matrix and / or a color image obtained from such a matrix.

In known manner, for example documents FR 11714352 or FR 1103919, a matrix that can be personalized by means of a laser to produce a color image comprises a color layer comprising elements, each of a single basic color, superimposed with at least one occulting layer sensitive to the laser.

A method of (re) producing a color image spatially corresponds point-to-point to said image to (re) produce to a matrix. Each point of the matrix comprises at least a portion of at least one element of each of the basic colors. Each corresponding point in the image defines a hue. The colorimetric decomposition of this hue on the n base colors of the color base of the matrix provides a component for each base color. An element of the matrix is obscured, by laser firing, according to said component.

Such a color image produced by personalization is advantageously used for an identity document, for example to make a passport identity photo. In this context it is advantageous to have a security device to certify the origin of the matrix and / or the image.

A security device is a difficult means to reproduce in order to make the task of a forger more difficult, advantageously controllable so that it can be verified and advantageously linked to the component, here the matrix and / or the image, in order to make detectable a possible counterfeiting. The invention proposes a security device linked to the matrix and a personalization method making it possible to link such a security device to the image and, where appropriate, to the carrier. The subject of the invention is a security device comprising a matrix adapted to be personalized by means of a laser for producing a color image, comprising a color layer comprising elements, each of a single basic color, and at least one laser-sensitive blackout layer, wherein the shape of at least one element is changed.

According to another characteristic, the modified element overlaps, at least partially, with at least one element of another color, the color of the modified element being applied in the zone of encroachment.

According to another characteristic, the modified element encroaches on at most two elements.

According to another characteristic, the modified element is the one whose color is least present on average in the color image.

According to another characteristic, the modified element is the one whose color is most present on average in the color image.

According to another characteristic, the extent of a modification is less than 12 pixels of the matrix, preferably less than 5 pixels.

According to another characteristic, the modification draws at least one alphanumeric symbol.

According to another characteristic, the modification draws an identifier of the transmitter, preferably a monogram.

According to another characteristic, the modification is periodically repeated in the matrix.

According to another characteristic, the modification saves an area of the matrix, preferably a central zone.

According to another characteristic, the elements are lines preferably having a width of two pixels of the matrix. The invention further relates to a method of customizing a matrix according to any one of the preceding claims, wherein at least one pixel of the matrix is customized according to the hue of the corresponding pixel of the image and the effective color of the image. pixel of the matrix.

According to another characteristic, at least one pixel of at least one modification is personalized according to the hue of the corresponding pixel of the image and the predictable color of the pixel.

According to another characteristic, a modification is selectively personalized by considering the effective color of the pixels or the predictable color of the pixels so as to encode at least one datum.

According to another characteristic, said at least one datum comprises an attribute of a carrier. Other characteristics, details and advantages of the invention will emerge more clearly from the detailed description given below as an indication in relation to drawings in which: FIG. 1 illustrates a matrix and its correspondence with an image, FIG. 2 illustrates a first arrangement of the color elements of a matrix; FIG. 3 illustrates another arrangement of the color elements of a matrix; FIG. 4 illustrates a first feature of the invention; FIG. use of the invention to form a symbol, - figure 6 illustrates a use of the invention to form a monogram, - figure 7 illustrates a periodic use of the invention, - figure 8 illustrates a saving on a part of the invention. the matrix, FIGS. 9 and 10 illustrate two embodiments of the personalization laser shot.

In order for the invention to be better understood, some reminders may be useful. As illustrated in Figure 1, a matrix 1 adapted to be personalized by means of a laser for producing a color image comprises a color layer 2, superimposed with a blackout layer 3 sensitive to the laser. The color layer 2 comprises a arrangement, typically periodic, of elements 4,4c, 4m, 4y, 4w, each of a single basic color, organized into sets or points 7 of the matrix 1. Each point 7 comprises at least a part of an element 4 of each basic color. Thus a point 7 comprises at least once each of the n colors. The n colors form a color base. Also n is at least 3. A colorimetric base commonly used has the n = 4 colors: White, Cyan, Yellow and Magenta, advantageously arranged in this order.

According to a first arrangement, illustrated in FIG. 2, a point 7 of the matrix 1 comprises four square elements, each of one of the four colors: a cyan element 4c, a magenta element 4m, a yellow element 4y and a white element (in white English) 4w.

According to another arrangement, illustrated in Figure 3, a point 7 of the matrix 1 comprises four elements, always one of four colors: cyan 4c, magenta 4m, yellow 4y and white 4w, arranged in line. Such an arrangement is advantageous in that it simplifies the production of the color layer 2, typically by offset printing.

An occulting layer 3 is an initially transparent layer becoming dark as it receives a laser shot. At least one such occulting layer is disposed above and / or below the color layer 2, to allow the realization of a direct and / or reflected concealment.

An image 5 to be reproduced is spatially divided into dots or pixels 6 according to the same arrangement (same number of rows and columns) as the points 7 of the matrix 1. A dot or pixel 6 of the image 5 is associated with a point 7 of the matrix 1.

It should be noted that the definition of a pixel, as the smallest relevant element, is here variable. A pixel 6 of the image 5 is a point 6 of the image 5. On the contrary a pixel 8 of the matrix 1 is substantially smaller. A distinction can be made between a pixel 8 of the color layer 2 or a pixel of the blackout layer 3, however it is advantageous that the two correspond. A pixel 8 of the image layer 2 is advantageously of the smallest achievable size, and is approximately 30 μπι. Figure 3 illustrates linear elements of two pixels 8 of width. This pixel size 8 is still compatible with the resolution of the laser firing process which is also of the order of 30 μm.

A method of (re) producing a color image spatially spatially associates said image 5 with (re) producing at a matrix 1, so that each point 7 of the matrix 1 is spatially associated with a point / pixel 6 of the image 5. A dot 6 of the image 5 defines a hue. A colorimetric decomposition of this hue on the n base colors of the colorimetric base of matrix 1 provides a component for each base color. A pixel 8 of the matrix 1, of this basic color, can then be obscured, by laser firing, according to said component. The occultation is inversely proportional to said component, in order to express the residual base color according to this component. Thus for a pixel 6 of the image 5 having a hue comprising 30% of the yellow base color, a pixel 8 of the matrix 1 is obscured at 70%.

These reminders being given, the invention will now be described. As shown in Figure 3, the matrix 1 has an arrangement, preferably periodic, for example here according to elements 4c, 4m, 4y, 4w continuous linear of each of the n base colors, for example here arranged horizontally relative to the picture 5

According to one characteristic of the invention, the shape of at least one element 4c, 4m, 4y, 4w is modified. This is illustrated in FIG. 4. Thus a modification 9a modifies the element 4m, normally magenta, with a pixel of the basic color of the element 4c, ie cyan. Similarly modifications 9b, 9c modify the element 4w, normally white, with cyan pixels. A modification 9d modifies the element 4y, normally yellow, with a cyan pixel. Finally a 9th modification affects the element 4c, normally cyan, with a white pixel.

Thus an element 4c, 4m, 4y, 4w is superimposed, at least partially, and encroaches on an element of another color and imposes its color in the overlap / encroachment zone. It follows that at least one pixel 8 of the matrix 1 is not of the predictable basic color.

This first characteristic produces a variation forming a detectable pattern, preferably with the naked eye, or otherwise by means of a magnifying glass. This detectable pattern acts as a characteristic signature of the producer or emitter of the matrix 1 and thus makes it possible to guarantee the origin of the origin of said matrix 1.

In this sense, this characteristic produces a security device that links matrix 1 to its producer / transmitter. This characteristic, buried in the color layer 2, is relatively difficult to modify a posteriori, once the integrated color layer 3, with the occulting layer 3 and other possible layers in a matrix 1, typically by lamination.

As illustrated in the preceding examples, a modification 9 advantageously relates to a single color, here cyan, which encroaches on the other colors as illustrated by the modifications 9a-d or alternatively which disappears and is replaced by white as illustrated by the amendment 9e.

A modification 9 relates to an element 4 in that it overlaps and is superimposed with at least one other element 4, ie an element of another color. A modification 9e can only concern an absence of a color, however such a modification 9e is then little visible. Also a modification 9 advantageously encroaches on at least one element 4.

According to another characteristic, so that the modification 9 does not have a too large extent, at the risk of distorting or making the image 5 noticeable, the modified element 4 is superimposed with at most two other elements. These encroached elements are advantageously neighbors and contiguous with the modified element 4.

According to an advantageous characteristic, the modified element 4 is chosen so as to be the most visible. For this, the modified element 4 is chosen such that its color is the least present on average in the image 5. Thus, for a photo ID 5 image, the cyan is advantageous, in that it is generally absent or very little present, and this for all types of skin color and / or hair. It follows, according to the embodiment of the customization, as described above, a modification 9 of this color, substantially absent from the image 5, is then lasérisée black.

According to an alternative characteristic, the modified element 4 is chosen so as to be the least visible. For this, the modified element 4 is chosen such that its color is the most present on average in the image 5. Thus, for a photo ID photo 5, the magenta is advantageous, in that it is generally very present, mainly in the skin and this for all types of skin color. It follows, according to the embodiment of the customization, as described above, that a modification 9 of this color is not lasérisée.

According to another characteristic, in order to limit the extent of the modification 9 and therefore its impact on the image 5, the extent of the modification 9 is advantageously less than 12 pixels of the matrix 1, preferably less than 5 pixels.

According to one embodiment, more particularly illustrated in FIG. 5, a modification 9 is such that it draws a symbol.

According to one embodiment, such a symbol may advantageously be an alphanumeric symbol. As illustrated in FIG. 5, a height of 4 pixels 8 of the matrix 1 makes it possible to draw certain alphanumeric characters. As illustrated in FIG. 6, a height of 5 pixels 8 of the matrix 1 makes it possible to draw substantially all the alphanumeric characters.

According to another characteristic, the modification 9 draws an identifier of the transmitter, preferably a monogram. Thus, as illustrated in Figure 6, a monogram comprising a sequence of 3 letters can be used to indicate the country issuing a travel document or identity. A sequence of 3 letters can typically be drawn over an area less than or equal to 12 pixels 8.

According to one embodiment, illustrated in FIGS. 7 and 8, the modification 9 is periodically repeated on the surface of the matrix 1. As illustrated in FIG. 7, a repetition on the entire surface of the matrix 1 may be detrimental to a good "reading" of the image 5. Also according to an alternative illustrated in Figure 8 no change 9 is disposed in at least one spared area 10. Said area 10 spared may be for example a central area. Thus, for an identity photo, the spared zone 10 is advantageously an oval covering more or less the face, to leave intact the details (eyes, nose, mouth, etc.) useful for a facial identification. The invention also relates to a method for personalizing such a matrix 1.

In a conventional manner, as previously described, a pixel 8 of the matrix 1 is customized according to the hue of the corresponding pixel 6 of the image 5. A pixel 8 of the matrix 1 is thus laserized according to the component of said hue and the base color of the pixel 8.

Typically, the base color of a pixel 8 is the predictable base color of this pixel 8, the color it is said to have depending on its position. Thus a pixel 8 is deemed to have the color of the element 4c, 4m, 4y, 4w in which it is located. However, the first characteristic of the invention is advantageously to modify this. Thus, with reference to FIG. 4, the pixel of modification 9a has, after modification, an effective cyan color, while its predictable color is magenta, since it is located in an area belonging to a magenta element 4m.

It is possible to use a conventional customization method, without taking into account modifications 9, or considering that each pixel 8 is of its predictable color.

Such a method, applied indiscriminately, for example to the entire image, is such that typically used by a counterfeiter. This can detect a counterfeit.

On the contrary, a personalization method according to the invention obscures a pixel 8 as a function of its effective color. According to the invention, the actual color of a modification 9 is different from the predictable color. This mode of personalization is advantageous in that the customization requires a knowledge of the exact mapping of the matrix 1 including the modifications 9 applied. This knowledge can be obtained by reusing the cartography used during the realization of the matrix 1. This mapping is not normally accessible to a counterfeiter. This mapping can still be obtained by re-reading the effective color of the color layer 2 of the matrix 1. Such a replay requires a pointed technology that is not necessarily accessible to a counterfeiter.

It is still possible, according to the invention, to mix the two previous customization modes.

FIGS. 9 and 10 illustrate comparatively the two personalization methods applied respectively to the same pattern, here the matrix detail 1 of FIG. 7. Said pattern occupies two pixels 6 of the image 5. It is assumed that the hue of these two pixels 6 is identical and decomposes with the following components: cyan 0%, magenta 50% and yellow 100%. Thus a pixel 8 of the matrix 1 of yellow color is not obscured, a magenta 8 pixel is obscured at 50% which is represented by a gray 50% and a pixel 8 cyan is completely obscured what is represented by black .

FIG. 9 illustrates the result by considering the predictable colors of the pixels 8 of the matrix 1. While FIG. 10 illustrates the result by considering the effective colors of the pixels 8.

It appears that a customization according to the predictable color tends to mask the modifications 9, whereas a customization according to the actual color has, on the contrary, tend to underline the modifications 9. This makes it possible to make visible the personalization process used and to detect a counterfeit.

Above all, a customization according to the invention, in that it takes into account the actual color of a modification 9 and the hue of the image 5 for the corresponding point 6, advantageously makes it possible to create a link between the matrix 1 and the image 5 reproduced by the customization.

As described above, a modification 9 of an element 4 makes it possible to bind a matrix 1 to its issuing authority and thus guarantee its origin.

The personalization process further allows matrix 1 to be linked to image 5.

A personalization method combining the two previous modes of personalization is advantageous in that it allows, considering the predictable color, to hide the modifications 9 in certain areas of the image, and on the contrary, by considering the actual color, d highlight the changes 9 in other areas of the image.

This can be advantageously used to selectively customize certain changes 9 according to the actual color or the predictable color so as to perform coding, for example data.

Such a datum may be a code thus advantageously concealed in the reproduced image in order to constitute a hidden signature. The absence of such a signature can detect a counterfeit.

According to a first embodiment, a matrix 1 comprises a plurality of modifications 9. A scheduling of these modifications 9 makes it possible to define a sequence of succession / reading. The customization mode allows for binary coding. Thus a modification 9 customized according to the effective color codes a 1, respectively a 0, while a modification 9 customized according to the predictable color defines a 0, respectively a 1.

According to another embodiment, more particularly adapted to the coding of a number among N, such for example a date calendar, a matrix 1 comprises N, for example 31, modifications 9. One of these modifications 9 is customized according to the color effective, respectively predictable, and designates the coded number, while the other modifications 9 are customized according to the predictable color, respectively effective.

Any other mode of coding imaginable by those skilled in the art can still be used.

Such coded data may also advantageously comprise an attribute of a carrier of the document containing the security device. An example of attribute is the date of birth of the wearer, which can be encoded by any of the previously described methods. This advantageously makes it possible to bond the matrix 1 with the wearer, thus further reinforcing the safety of the device.

Claims (15)

Safety device comprising a matrix (1) adapted to be personalized by means of a laser for producing a color image (5), comprising a color layer (2) comprising elements (4), each of a single color base, and at least one occulting layer (3) sensitive to the laser, characterized in that the shape of at least one element (4) is modified. 2. Device according to claim 1, wherein the element (4) modified encroaches, at least partially, on at least one element (4) of another color, the color of the element (4) modified being applied in the encroachment area. 3. Device according to claim 2, wherein the element (4) modified encroaches on at most two elements (4). 4. Device according to any one of claims 1 to 3, wherein the element (4) modified is the one whose color is least present on average in the color image (5). 5. Device according to any one of claims 1 to 3, wherein the element (4) modified is the one whose color is most present on average in the color image (5). 6. Device according to any one of claims 1 to 5, wherein the extent of a modification (9) is less than 12 pixels (8) of the matrix (1), preferably less than 5 pixels (8). 7. Device according to any one of claims 1 to 6, wherein the modification (9) draws at least one alphanumeric symbol. 8. Device according to any one of claims 1 to 7, wherein the modification (9) draws an identifier of the transmitter, preferably a monogram. 9. Device according to any one of claims 1 to 8, wherein the modification (9) is periodically repeated in the matrix (1). 10. Device according to any one of claims 1 to 9, wherein the modification (9) spares a zone (10) of the matrix (1), preferably a zone (10) central. 11. Device according to any one of claims 1 to 10, wherein the elements (4c, 4m, 4y, 4w) are lines, and preferably have a width of two pixels (8) of the matrix (1). 12. A method of customizing a matrix (1) of a security device according to any one of the preceding claims, characterized in that at least one pixel (8) of the matrix (1) is customized according to the hue of the corresponding pixel (6) of the image (5) and the effective color of the pixel (8) of the matrix (1). 13. Customization method according to claim 12, wherein at least one pixel (8) of at least one modification (9) is customized according to the hue of the corresponding pixel (6) of the image (5) and the predictable color of the pixel (8). A personalization method according to any one of claims 12 to 13, wherein a modification (9) is selectively personalized by considering the effective color of the pixels (8) or the predictable color of the pixels (8) in such a way as to encode less data 15. Personalization method according to claim 14, wherein said at least one data item comprises an attribute of a carrier.