WO2011124774A1

WO2011124774A1 - Method for customizing latent embedded images and document thus produced

Info

Publication number: WO2011124774A1
Application number: PCT/FR2011/000126
Authority: WO
Inventors: Jean Pierre Lazzari; Jean Marc Lazzari
Original assignee: Jean Pierre Lazzari; Jean Marc Lazzari
Priority date: 2010-04-07
Filing date: 2011-03-10
Publication date: 2011-10-13
Also published as: EP2580065A1; FR2958777A1; EP2580065B1

Abstract

The invention relates to a device for customizing a latent image (12) embedded under a transparent mechanical protection layer (41), wherein the latent image consists of printed, uniformly distributed so-called sub-pixels which are in the primary colors plus the color white, the surface of each sub-pixel of the latent image being partially or totally transformed into a non-reflecting dark colored surface by means of the impact of a laser beam (51) through the transparent protective layer, thus forming the greyscale of the final customized image. The invention can be used for the customization of credit cards.

Description

METHOD FOR CUSTOMIZING RECESSED LATENT IMAGES AND REALIZED DOCUMENT

DESCRIPTION

Field of application of the invention

The present invention relates to a method of personalizing embedded latent images. It finds applications especially in credit cards or other official documents (identity, subscription, etc.). The invention relates more particularly to the personalization of latent images protected by a transparent mechanical protection.

State of the art:

Some banks offer their customers to print on their credit card an image of their choice. For this, the customer must send by email, to his bank, an image which is preferably his photo ID. During the manufacture of the card, the bank will print the image before the deposit of the protective layer.

This solution imposes an individual treatment of the credit card during its manufacture, which increases its price. Moreover, the sending by email of a photo, associated with confidential information, always presents risks of diversion.

In order to avoid these disadvantages, many companies are looking for ways to personalize credit cards at the last moment, that is, when the credit card is provided to the customer. So the mass production is the same for all credit cards, and there is no more risk of misuse of information online.

For this, some devices provide a latent image consisting of an organic layer, monochrome or a metal layer. These layers are coated with a transparent protective layer. The personalization that is to say the formation of the final image, is performed by a laser beam that burns the organic layer or engraves the metal layer, showing a certain contrast between the parts treated by the laser beam, and untreated parts. If these devices are very simple, they prohibit color, which greatly limits their application.

Other devices use several multilayer layers, protected by a transparent layer. The stacked sub-layers having different colors, it is possible to produce color images by selective ablation of the sub-layers through the transparent layer. JP2004082493 (A), shows a similar example. If these devices make it possible to produce color images, the superposition of the sub-layers, their selective ablation, make these solutions delicate and especially very expensive.

Patent FR 2451081 proposes the personalization of a latent image coated under a protective layer, by the use of micro capsules which by mechanical pressure, show different colors. If this device seems interesting in some aspects, it does not allow to show a quality image. Moreover, the application of the mechanical force necessary for the change of color, is incompatible with shapes or patterns of small size, essential to obtain a sufficient resolution of the desired image.

It is also known to reproduce images in a liquid crystal display by creating gray levels by a determined duration of opening of the liquid crystal with respect to the time of an image. This technology does not apply to make final images.

Object of the invention

The present invention aims to overcome these drawbacks by proposing a method of customizing a sunken latent image, to obtain a final color image of high _^ quality, low-cost laser treatment on an image latent of particular structure.

As such, the subject of the invention is a method of personalizing a latent image embedded in a transparent protective mechanical layer. The method consists of forming a latent image consisting of sub-pixels printed with primary colors uniformly distributed, these colors being reflective, then to reveal gray levels of a final image by a modulated emission of a laser beam on the sub-pixels for producing dark non-reflecting surfaces covering part or all of the surface of each sub-pixel.

According to particular implementations:

in addition to sub pixels with primary colors, sub pixels of white color equally uniformly distributed are added to constitute the pixels of the latent image, each quadruplet of sub-pixels forming a pixel;

the non-reflecting dark-colored surfaces covering part or all of the surface of the sub-pixels are obtained by carbonization of the sub-pixels by the laser beam through the transparent protective layer;

the non-reflecting dark-colored surfaces covering part or all of the surface of the sub-pixels are obtained by thermochromic effect or by photochromic effect, under the influence of the laser beam through the transparent protective layer.

The invention also relates to the document comprising an image produced according to the method above. In this document, the image being arranged under a mechanical protection layer, the embedded image is formed of sub-pixels which have surfaces printed with the primary colors when viewed by reflection and are regularly distributed on a support, these surfaces. being covered with dark non-reflective surfaces.

According to particular embodiments:

the dark non-reflecting surfaces are black in color and the sub-pixels are in the primary colors and also regularly distributed white colors;

the surface of the latent image is curved in order to allow an image incrustation in a flexible document. The invention thus proposes to make, during the mass production of the image support object, which may be a credit card, a latent image, deposited on this support and mechanically protected by a transparent layer, this image latent being printed according to the same manufacturing processes as those used for the standard manufacture of credit cards. At this stage of production, all latent images are identical and appear as white. Then in a second step, a laser beam, through the transparent protective layer, transforms the latent image into a personalized final color image.

Indeed, the latent image consists of small surfaces with primary colors (RGB): Red, Green and Blue, surfaces that will be called "sub pixels", each set (triplet) sub pixels (RGB) forms a pixel of the image. These sub-pixels are printed by inkjet, or any other technique known to those skilled in the art during the mass production of the carrier object, which may be a credit card or other identity document. This latent image, formed of regularly distributed sub pixels, is identical for all the objects of the same series. The latent image is then mechanically protected by a transparent coating.

Subsequently, in a second phase, the customization of the latent image is effected by a laser beam which, by thermal effect or photosensitive effect, reveals a dark color, preferably black, covering partially or totally the sub pixels surface. The dark coloration being formed between the surface of the sub-pixels and the field of view, the recovery of the sub-pixels by this coloration appears in the field of view by reflection of the light on the sub-pixels.

More specifically, the subject of the invention is a method of personalizing a latent image embedded in a transparent mechanical protection layer. The latent image consists of a regular set of small primary-color printed surfaces, essentially including red, green, and blue colors. In order to reinforce the white dominance, the invention advantageously provides for regularly adding small white areas. Each small surface constitutes a sub-pixel of the image, and a set (quadruplet) of sub-pixel red, green, blue and white constitutes a pixel of the image.

Each image can contain several million pixels, depending on the definition. The sub-pixels are arranged regularly to form the latent image. They are printed by any technique known to those skilled in the art, such as inkjet, for example. The surface, which supports the latent image, can be flat or curved. The colors of the sub pixels are reflective, in order to give the final image, once personalized, the maximum brightness in ambient light.

At this level of manufacture, the latent image consisting of all the pixels described above, appears as a white surface to the observer. The latent image is then coated with a transparent protective layer. All of these manufacturing steps, are common to all objects in the same series.

In a second step, the customization is carried out by a laser beam which through the protective transparent layer, reveals non-reflecting surfaces, dark colors, preferably black, which more or less cover the surface of the sub-pixels thus forming the gray levels of the final custom color image. The non-reflective surfaces made by the laser beam are obtained by thermal or photochromic effect.

In the most economical form of the invention, the colored surface of each sub-pixel is carbonized in part or in whole by the laser beam. In a more elaborate form, the ink used to color the sub-pixels has thermochromic properties or photochromic properties, known to those skilled in the art who, under the influence of either a thermal effect or a radiation effect of the laser beam causes a non-reflecting, preferably black, coloration on the treated parts.

Presentation of the figures:

In any case, the features and advantages of the invention will appear better after the description which follows, given for explanatory purposes and in no way limiting. This description refers to the accompanying drawings, in which:

FIG. 1 shows a credit card comprising the latent image according to the invention. FIG. 2 shows the same credit card once personalized by the laser beam through the protective layer.

FIG. 3 shows the "sub-pixels" of the latent image.

FIG. 4 shows the section of the latent image protected under the transparent protective layer.

FIG. 5 shows the personalization by the laser beam of the latent image.

FIG. 6 shows an example of gray levels obtained by the laser beam, of the personalized image.

Detailed description :

Figure 1 shows a credit card (11) on which, during its mass production, the latent image (12) has been printed. Any technique known to those skilled in the art printing can be used, including techniques commonly practiced to print the ^patterns' color cards. The latent image (12) may be located on a flat portion of the credit card, or on a curved surface, or in relief, such as, for example, the raised portions of the credit card numbers. At the end of manufacturing, the credit card is coated with a transparent protective layer like the current credit cards. At this level, standard credit card manufacturing processes are not modified.

Figure 2 shows the same credit card, the latent image (11) of Figure 1, has been customized, showing the final color image (21). If this image is a photo ID, it can preferably have the standardized dimensions of photo ID, 35mm by 45mm.

Figure 3 shows a detailed view of the latent image (12). It consists of small areas that we call "sub-pixels", regularly arranged. Each quadruplet of "sub-pixels" (31) of red color, (32) of green color, (33) of blue color, and (34) of white color form a pixel which may have a square shape according to the example of Figure 3. The "subpixels" can also be aligned forming monochrome bands in the previously described colors. The ink used to print the "sub-pixels" is preferably reflective. According to the example of FIG. 3, the "sub-pixels" are squares of Ιβμιη on the side. The pixel comprising the four "subpixels" according to this example has a square shape of 32μπι of side.

Figure 4 shows the section of a credit card (11) comprising the latent image (12), the assembly being coated with the transparent protective layer (41).

Figure 5 shows a credit card (11) including the latent image (12) coated with the protective layer (41). A laser beam (51) scans the entire surface of the latent image (12) to customize it through the protective layer (41), showing the gray levels of the final image, by performing dark, preferably black, non-reflective surfaces that partially or wholly cover the surface of each "sub-pixel". In its most economical form, the gray levels are obtained by carbonization of the color of the subpixels. other methods, known to those skilled in the art, use photochromic or thermochromic colors, which under the influence of the wavelength of the laser beam, or under the thermal influence of the laser beam, make it possible to reveal a color dark, which reflects very little light.

The reproduction of a digital image for example is according to the invention to be performed by laser beam (51) the gray level of each pixel of the scanned image by partial or total darkening, ^'especially by blackening, a or more sub pixels of each pixel of the reproduced image corresponding to a pixel of the digital image to be reproduced.

The area of the surface to be blackened above each sub-pixel ("above" means between the surface of the sub-pixels (12) and the laser beam (51), - (i.e. placing in the field of view of the image by reflection of the light) corresponds to that of the image to reproduce in order to reconstruct the same level of gray as that of this image for each of its sub-pixels.

Figure 6 shows examples of gray levels on the four "sub pixels" (31), (32), (33), and (34) of a pixel. According to this example, the laser beam (51) of FIG. 5 sweeps the latent image from left to right. For example, the impact of the laser beam on the surface of the "sub-pixel" (31) has generated a black surface (61) of lmx Ιμπι. Sweeping the "sub-pixels" from left to right for example, the laser beam, when the surface to be treated is larger, can leave a straight trace (62) of Ιμπι wide, and of length proportionate to the non-reflective surface required. ^■ A way of example in the "subpixel" (32) the non-reflective surface has a dimension of x 12μπι lpm. Other non-reflective surfaces (63) and (64) are shown on the "sub pixels" (33), and (34) respectively. At the extreme, some "sub pixels" can be completely covered with non-reflective surface, or conversely not be covered at all. According to the example given in FIG. 6, each "sub-pixel" can be covered with 16 x 16 laser impacts, thus forming 256 gray levels per "sub-pixel". According to the example of Figure 6, the identity photo of 35mm X 45mm, will then consist of more than 6 million pixels.

To reproduce the darkening of each sub-pixel, which will provide the gray level corresponding to each sub-pixel of the image to be reproduced, the intensity of the laser beam is programmed according to the gray levels of the image to be reproduced. These gray levels are recorded with their address in a memory of a digital processing unit. The predetermined scans are also recorded according to the image to be embedded on the document medium (global dimension, size of the sub-pixels, type of organization of the sub-pixels). Depending on the choice of scanning, the unit then controls the emission and displacement of the laser beam through suitable equipment, known to those skilled in the art, in order to reproduce the gray levels stored in a given image .

Claims

1. A method of personalizing an embedded latent image (12) under a transparent mechanical protection layer (41), characterized in that it consists in forming a latent image (12) consisting of sub-printed pixels (31 to 33) with the primary colors uniformly distributed, these colors being reflective, then to reveal gray levels of a final image (21) by a modulated emission of a laser beam (51) on the sub-pixels

(31 to 33) for producing dark non-reflecting surfaces (61 to 64) covering part or all of the surface of each sub-pixel

(31 to 34).

2. A method of personalization of latent image embedded in a transparent layer of mechanical protection according to claim 1, characterized. in that, in addition to the primary color sub pixels (31 to 33), evenly distributed white sub pixels (34) are added to form the pixels of the latent image.

3. A method of personalization of latent image embedded in a transparent layer of mechanical protection according to claim 1 or 2, characterized in that the non-reflecting surfaces of dark color (61 to 64) covering part or all of the surface of the sub pixels are obtained by carbonization of subpixels by the laser beam (51) through the transparent protective layer (41).

4. Embedded latent image personalization method under a transparent protective layer mechanical mechanism (41) according to one of claims 1 to 3, characterized in that the non-reflecting surfaces of dark color (61 to 64) covering part or all of the surface of the sub-pixels are obtained by thermochromic effect or by effect photochromic, under the influence of the laser beam (51) through the transparent protective layer (41).

5. Document in which is embedded a final image (21) obtained by the method according to one of the preceding claims, the final image

(21) being arranged under a mechanical protection layer (41), characterized in that the final embedded image (21) is formed of printed sub pixels which have surfaces with primary colors

(31 to 33) when viewed by reflection and are evenly distributed on a support (11), these surfaces being covered with dark non-reflecting surfaces (61 to 63).

6. Document according to the preceding claim, wherein the non-reflecting dark surfaces are black in color (61 to 64) and the sub pixels are in primary colors (31 to 33) and also white (34) regularly distributed.

7. Document according to claim 5 ^' or 6, characterized in that the surface of the latent image is curved.