Color laser personalization with high color saturation

Abstract

Method for producing a data carrier (20) of a security document (1) with a color image comprising the steps: Provide at least one substrate layer (100); Printing of at least two printing layers (120, 140, 160), each of the at least two printing layers (120, 140, 160) having a color pattern (130; 150; 170) which comprises different colored color areas (131-133; 151-153; 171-173), wherein the different colored color areas (131-133; 151-153; 171-173) have basic colors which together span a color space, wherein color areas of the same color (131-133; 151-153; 171-173) of the color patterns (130; 150; 170) of superimposed printed printing layers (120, 140, 160) are laterally offset, and the application of laser radiation for the local removal at different positions of at least parts (180) of color areas. (131-133; 151-153; 171-173) of the color pattern (130; 150; 170) or the color patterns (130; 150; 170) of the at least two printing positions (120, 140, 160), so that due to color addition or color subtraction based on the remaining and / or exposed portions of the color patterns (130; 150;170) Different color impressions are created at different locations, which together form the color image.;

Description

[0001] The invention relates to a method for producing a data carrier of a security document with a color image, a semi-finished product for producing such a data carrier, and a data carrier of a security document with a color image.

[0002] It is known from the prior art to integrate color images into data carriers of security documents. Data carriers can, in particular, be card-shaped lamination bodies made from one or more substrate layers, which form the security document itself or a component thereof.

[0003] Examples of security documents where the data carrier itself constitutes the security document include identity cards, driver's licenses, access cards, bank cards, etc. Examples of data carriers that are only part of a security document include passport cards or similar items, which may, for example, be bound as a page in a booklet.

[0004] Color images are used in particular to display personalized information, such as a portrait of a person to whom the corresponding data carrier is assigned. The interest here is to prevent, as far as possible, any falsification or alteration of the information stored in the color image. Information stored on the data carrier using laser radiation has proven to be particularly difficult to imitate and / or falsify.

[0005] WO 2011 / 124 774 A1 describes a device for the individual design of a latent image embedded under a transparent mechanical protective layer. The latent image consists of printed, uniformly distributed subpixels in the primary colors plus white. The surface of each subpixel of the latent image is partially or completely transformed into a non-reflective dark color area by means of a laser beam passing through the transparent protective layer, thereby forming the grayscale levels of the final individual image. An application for the individual design of credit cards is described.

[0006] German patent DE10 2010 010 072 A1 describes a marking device for a valuable or security document and a method for permanently marking valuable and / or security documents in a multi-colored manner, particularly with individual marking. The method for permanently marking a valuable or security document in color comprises the following steps: providing a document body that includes areas of different colors, each area being a single color; providing a marking device that includes at least one laser light source for generating laser light and a light guide device that is coupled to the at least one laser light source, such that a focus of the laser light from the laser light source can be positioned in a controlled manner on or within the document body of the valuable or security document;Iterative, targeted positioning of the focus on or within the document body and illumination of the laser light to selectively and locally alter the color of one or more areas, so that the document subsequently appears multicolored to a human observer when illuminated with white light. The laser light is applied using short or ultrashort laser pulses with a pulse duration of less than 100 ps or less than 10 ps. This allows for the exploitation of non-linear interactions between the material of the valuable or security document and the laser light for marking. This enables improved focusing of the laser light and, consequently, a higher density of the colored markings that define the color, thus allowing for higher color intensity.

[0007] German patent DE 10 2010 062 046 A1 describes how, to create a novel security feature for valuables and / or security documents, a valuables and / or security document is created that preferably has at least one document layer. In one or more first layers, there is a first pattern formed from first image elements. Furthermore, in one or more second layers, there is a second pattern formed from second image elements and arranged precisely to the first image elements of the first pattern. The second image elements are located between the first image elements and the outer surfaces of the valuables and / or security document. A second image element is arranged only over a portion of the first image elements. The first pattern elements are transparent and / or translucent.The remaining value and / or security document is also designed to be transparent and / or translucent with respect to a line of sight (S) in the area of ​​the first pattern elements up to the second pattern elements, so that information defined by the patterns is perceptible in transmitted light.

[0008] German patent DE10 2018 113 575 A1 describes a security element for use in a security document, comprising a first layer. The first layer comprises an area of ​​multiple surface regions, with adjacent surface regions having different colors and the surface regions arranged in alternating colors. At least one surface is present, exhibiting a structure comprising structural elements with dimensions of less than 200 micrometers (200 µm). The structural elements are arranged relative to the surface regions of the first layer such that a colored image is generated that differs from the image generated solely by the surface regions of the first layer.

[0009] US Patent 2014 361 527 A1 describes a method for producing color laser images. A latent image, consisting of colored subpixels and non-colored areas, is personalized by a laser beam acting on the laserable layer located beneath the colored subpixels and non-colored areas to produce a final personalized color laser image.

[0010] In a color laser engraving process described in US 2005 001 419 A1, a document is engraved with a surface layer and one or more sublayers. The sublayer contains different colors and arrangements of ink. A laser creates openings in the surface layer to expose colored ink in the sublayer and produce colored images and / or text.

[0011] WO 2012 / 117 168 A1 describes a method for producing a document with a color laser image of high reflectivity, wherein the document comprises a sheet of laserable material, subpixels in primary colors, and a white substrate, wherein grayscale levels of the color image are generated by carbonizing the laserable material using laser radiation. In some embodiments, the subpixels are separated by transparent areas that increase reflectivity and enhance the white components of the personalized image.

[0012] In previously known methods and data carriers, individualization is usually achieved by creating blackened areas. This generally results in dark color images. In other embodiments, parts of an opaque layer remain in the color image, revealing the colored components beneath. Therefore, color images with high color saturation cannot be satisfactorily produced.

[0013] The invention is based on the objective of creating a method for producing a data carrier of a security document with a color image, a semi-finished product of a data carrier of a security document and a data carrier of a security document with a color image, in which the color image has a high color saturation.

[0014] The problem is solved by a method with the features of claim 1, a semi-finished product with the features of claim 9, and a data carrier for a security document with the features of claim 11. Advantageous embodiments of the invention are set forth in the dependent claims. Basic idea of ​​the invention

[0015] The basic idea of ​​the invention is to create a data carrier for a security document by printing color patterns, generated from color ranges of primary colors within a color space, superimposed onto a substrate layer. The color patterns are printed in such a way that the color ranges of each primary color are laterally offset relative to the color ranges of the same primary color in the immediately preceding color pattern. Each color pattern is printed using a single layer. Subsequently, at least parts of the color ranges of at least the topmost color pattern, and optionally of several or all color patterns, are selectively removed to create a color image with varying color impressions at different locations. An advantage of the invention is that no blackened areas need to be inserted to create the color image, which would otherwise darken it.Furthermore, there are no remaining areas of a cover layer as in some prior art embodiments. This allows for a color image with high color saturation. Definitions

[0016] A color area is a monochromatic surface. A color area can have any shape. Color areas in the shape of a stripe, square, or rectangle are preferred.

[0017] The primary colors of a color space are those colors that, together, define a color space (gamut) through color addition or subtraction. Color ranges containing the primary colors can be used to create the colors of the color space by varying the proportions of the different primary colors, for example, by selecting the area of ​​each color range. If a color image is broken down into pixels, each pixel contains subpixels that are assigned to the individual primary colors. By varying the area of ​​these subpixels, the perceived color is adjusted based on color subtraction or addition at the corresponding pixel. For example, cyan, magenta, and yellow represent primary colors of a color space whose colors can be reproduced with common inkjet printers or color copiers. The perceived color is determined by color subtraction.Another color space comprises the primary colors red, green, and blue. This color space is used for color addition, for example, in color LCD displays or for viewing data carriers with colored translucent and / or transparent areas using backlighting.

[0018] A permutation is an arrangement of objects in a specific order. When we speak here of a permutation of color ranges with the primary colors of the color space, the permutation comprises exactly one color range for each primary color of the color space.

[0019] A color pattern is a pattern formed from adjacent color areas.

[0020] If a color pattern is formed based on a permutation of the primary colors of a color space, it is considered to be the same as another color pattern formed based on the same permutation of the primary colors if the permutation occurs in the same sequence in both color patterns, regardless of edge effects where the permutations in the two compared patterns are incomplete and possibly different. For example, if two color patterns are formed by concatenating the permutation of striped color areas of the primary colors of a color space, the color patterns are the same if a permutation exists whose concatenation can generate both color patterns except for the start and / or end regions, where the start and / or end regions do not constitute a complete permutation of the color areas of the primary colors of the color space.

[0021] A material is described as transparent to light of specific wavelengths if it allows an image to be formed through it according to the principles of geometric optics using light of those specific wavelengths. For example, a clear window pane is transparent to light in the visible wavelength range. A red-tinted transparent plastic film is transparent to light in the "red" wavelength range.

[0022] A material that is translucent to light of a specific wavelength range transmits light of that wavelength range but scatters it diffusely within its interior. For example, a frosted glass pane or a diffusing lens is translucent to light in the visible wavelength range.

[0023] A substrate layer is understood to be a physically self-supporting layer. For example, plastic films that can be handled without support layers, sheets of paper, etc., are substrate layers within the meaning of this definition.

[0024] Printed layers or print layers that rely on a substrate layer as a support are not substrate layers in the sense of the definition used here. However, a printed layer that forms a color pattern is, or at least forms in the area of ​​the color regions, a material layer that has a finite material thickness and is distinct from other substrate layers or material layers.

[0025] A printed layer that forms a color pattern can also contain colorless, clear areas that, for example, separate color areas from one another. This allows the printed layer to be formed as a single material layer with a uniform thickness, at least in contiguous areas where a color pattern is printed.

[0026] A solid-color area or a clear colorless area is not considered a color pattern. A solid-color printed layer does not exhibit a color pattern within the meaning of the invention described herein.

[0027] Printing or imprinting a layer containing a color pattern refers to any process that can reproducibly and controllably create distinct, monochromatic color areas arranged side by side in a thin layer. A layer produced in this way is called a printed layer.

[0028] White light is defined as light that has a continuous wavelength spectrum in the visible wavelength range. Preferred embodiments

[0029] In particular, a method for producing a data carrier of a security document with a color image is created, which includes the steps of: providing at least one substrate layer; Printing of at least two layers, each of the at least two layers having a color pattern comprising different colored color areas, wherein the different colored color areas have primary colors that together span a color space, wherein color areas of the same color in the color patterns of printed layers are laterally offset, The application of laser radiation for the local removal at different positions of at least parts of color areas of the color pattern or color patterns of the at least two printed layers, so that, due to color addition or color subtraction, different color impressions are generated at different locations based on the remaining and / or exposed parts of the color patterns, which together form the color image.

[0030] Accordingly, a semi-finished product is created for the production of a security document with a color image, which includes: at least one substrate layer; at least two printed layers printed on top of each other onto the at least one substrate layer, each of the at least two printed layers having a color pattern which includes different colored color areas, wherein the different colored color areas have basic colors which together span a color space, wherein color areas of the same color in the color patterns of printed layers printed on top of each other are laterally offset.

[0031] Such a semi-finished product thus exhibits a latent, not yet individualized image. By means of localized laser radiation, different color impressions can be created by locally removing parts of the color areas of one or more color patterns at different locations, in order to form the finished color image. Here, for example, a portion of a color area of ​​the topmost color pattern—that is, the color pattern furthest from the at least one substrate layer onto which the printed layers with the color patterns are successively printed—is selectively removed to reveal a color area of ​​the underlying color pattern, i.e., the one closer to the at least one substrate layer. If, for example, a total of three printed layers with a color pattern are printed one above the other onto the at least one substrate layer, then the portions of the color areas of the two uppermost, i.e.,The color pattern furthest from at least one substrate layer is removed to expose an underlying color area of ​​the pattern printed directly onto the substrate layer using a printing layer. The exposed and remaining color areas at a given point on the processed semi-finished product determine the resulting color impression at that point. Because the removal of parts of the color areas is carried out in a targeted, localized manner, different color impressions from the color space can be generated at different locations. These together constitute the color image.

[0032] In such a semi-finished product already provided with a color image, at least parts of color areas of the color pattern or color patterns of the at least two printed layers are removed at various positions by means of laser radiation, so that due to color addition or color subtraction, different color impressions are created at different locations due to the remaining and / or exposed parts of the color patterns, which together form the color image.

[0033] Such a semi-finished product can then be further processed into a data carrier for a security document by, for example, adding further security features or security elements and / or inserting the semi-finished product with further substrate layers, for example, into a lamination body, which forms a finished security document body in the form of a data carrier for a security document.

[0034] Because the parts of the color areas are removed, no colored components of these removed parts of the color areas remain in the finished data carrier or semi-finished product, which could otherwise also lead to a darkening of the color image.

[0035] The individual printing layers are preferably designed such that each forms a layer on the surface of the substrate or a previously applied printing layer, and does not penetrate the substrate layer or the previously applied printing layer. Preferably, a printing layer has a layer thickness of as uniform a degree as possible across the color areas.

[0036] In some embodiments, a thin, high-transmittance layer, preferably transparent and particularly preferably clear and colorless, can be arranged or formed between a substrate layer and a printed layer forming a color pattern, or between two printed layers, each forming a color pattern. The thin layer can also be translucent, with diffuse scattering having no perceptible effect due to the small layer thickness. The thin layer is not self-supporting. This thin, preferably transparent, and particularly preferably clear and colorless, layer can be printed using any method or formed using a conventional method for applying varnish layers.

[0037] The thin layer is preferably made of a material that prevents the colorants of a printed layer from penetrating into the adjacent substrate layer or printed layer. If the substrate layer is porous or open-pored, this thin, preferably transparent, and particularly preferably clear, colorless layer can also be formed wholly or partially within the substrate layer surface, provided that this thin layer serves the purpose of ensuring that the printed layer applied to it forms as a separate layer and that no colorants from it penetrate into the substrate layer.

[0038] In general, it is advantageous if the thin, preferably transparent, layer is colorless.

[0039] Particularly preferred is the thin, preferably transparent, layer based on a curable plastic. This is preferably curable or already cured by radiation, for example UV radiation.

[0040] Alternatively or additionally, the printing layers can also be applied using curable preparations, which are preferably cured before the next printing layers are applied. This also prevents the different colors or colorants from running or diffusing into each other.

[0041] A thin, preferably transparent layer between a substrate and a printing layer and / or between the individual printing layers also facilitates the targeted removal of parts of the color areas without altering underlying color areas of another printing layer.

[0042] Printed layers are also considered to be printed on top of each other if a thin, preferably transparent, and especially preferably clear, colorless layer is applied between them, the thickness of which is on the order of the thickness of one of the printed layers. A material thickness and a layer thickness are considered "on the order of" if the thickness of the thin layer does not exceed 10 times the thickness of the printed layer.

[0043] A print layer is also considered to be printed on a substrate layer if a coating is applied to the substrate layer, onto which printing takes place.

[0044] It has proven particularly advantageous to print the at least two layers in such a way that the color patterns of the at least two layers exhibit the same sequence or sequences of color areas with respect to a specific direction. This ensures, for example, that identical color patterns can be printed on top of each other, except, if necessary, at the edges, with their color areas of the same color shifted or offset relative to each other by a uniform offset. The offset of the color patterns ensures that, at every point, as in the individual color pattern, the individual primary colors are adjacent to each other, and, in the case of the superimposed color patterns, color areas of the primary colors are also arranged one above the other. Thus, at least two different primary colors can be used alternatively at every point to create a color image with high color saturation.

[0045] It has proven advantageous that the color samples are all based on a permutation of color ranges with the primary colors of the color space. The color samples are thus preferably based on one and the same permutation of the color ranges of the primary colors. The permutation does not need to be complete at the edges of the color sample. This allows for a simple and precise prediction of the position of the individual color ranges of the different primary colors, even in overprinted color samples.

[0046] To reliably ensure that color areas are laterally offset compared to color areas of the same base color printed immediately before with one of the at least two printing layers, and preferably even laterally offset compared to the same color areas of all color samples printed previously with one of the at least two printing layers, the color samples are printed using the two printing layers in such a way that the center distance of adjacent color ranges within the respective color sample is the same and identical between the color samples of different at least two printing layers.

[0047] Preferably, the color areas are designed such that adjacent color areas of at least the uppermost color pattern, i.e., the color pattern of the printing layer of the at least two printing layers that are furthest away from the at least one substrate layer, abut each other at least along one direction. Preferably, the color areas of at least the uppermost color pattern completely cover a closed, contiguous area without overlapping each other in the printing layer itself.

[0048] In particular, lower color patterns, i.e., color patterns overprinted by a color pattern of at least one of the at least two printing layers, may also have transparent, colorless intermediate areas between the color areas in the printing layer. These are preferably formed using a transparent and colorless printing preparation or ink, thereby achieving a uniform material thickness of the printing layer in the area of ​​the color pattern.

[0049] In other embodiments, the transparent, colorless areas can also be formed by "gaps" in the printed layer.

[0050] Preferably, however, all color patterns have the same area and are completely filled with color areas that abut each other but do not overlap in their respective printing positions. In this case, the color patterns overlap completely, except possibly in edge areas, where edge areas for this definition have a maximum width that is less than the width or center-to-center distance of the color areas multiplied by the number of primary colors of the color space.

[0051] A particularly optimal, compact arrangement of color areas is achieved when the center positions of the color areas of a color pattern in one of the at least two printing layers are laterally offset by a distance relative to the center positions of corresponding color areas of the color pattern in the immediately preceding of the at least two printing layers. This offset is calculated as the product of the center-to-center distance of adjacent color areas and a quotient formed by the number of different primary colors in the color space and the number of at least two printing layers containing a color pattern. For example, if the color space contains three primary colors (N=3) and color patterns with a total of two printing layers (M=2) are printed on top of each other, the color areas of the color pattern in the second printing layer are laterally shifted by one and a half center-to-center distances of the color areas (N / M=3 / 2).If the color patterns are formed from striped or cuboid, possibly square, color areas, the distinguished direction is determined by the direction along which the color areas are arranged laterally in a sequence. For striped color areas, for example, perpendicular to the stripe direction.

[0052] Overall, the invention makes it possible to achieve a higher pixel resolution in the color image formed by means of laser radiation by partially or completely overlapping color areas than is possible using only printed color areas.

[0053] For example, if color samples for a color space spanned by three primary colors are printed onto at least one substrate layer using three printing layers, color areas of all three primary colors are preferably printed superimposed at each point. The achievable pixel resolution is thus limited by the extent of the image areas, i.e., by the center-to-center distance of the color areas. For a single color sample, however, the achievable pixel resolution in the given example is three times lower, since the three color areas of the primary colors are arranged next to each other. Here, it is assumed that the pixel resolution is defined as the number of pixels per area, where each pixel can assume any chosen color impression based on all the primary color components or associated color areas that interact during color addition or subtraction and span the gamut.exhibits.

[0054] Color areas are preferably opaque, which allows for the generation of a color image for viewing in remission, i.e., for viewing from the side from which the color image is illuminated.

[0055] If the data carrier is made of transparent material above and transparent or translucent material below the color image, the color image can also be viewed using transmitted light, whereby the light is shone below the color image and the color image is viewed from the opposite top side. In such a case, the color areas are preferably transparent and / or translucent.

[0056] In order to add white areas to the color pattern, some embodiments provide that the at least one substrate layer, or a layer connected to the at least one substrate layer on the side facing away from the side onto which the at least two print layers are printed, is white or diffusely remitting. Thus, the at least one substrate layer, at least in the area of ​​the color image, or a substrate layer arranged below it and connected to the at least one substrate layer, can be white in the area of ​​the color image. A substrate layer that has a print layer that is white is also considered to be white.

[0057] In order to avoid manipulation and / or damage to the color image, preferred embodiments provide that at least one transparent cover layer, which covers and encloses the color patterns, is bonded to the at least one substrate layer by means of laser radiation after the removal of at least parts of the color areas of the color pattern or patterns of the at least two printed layers.

[0058] To add black components to the color image, additional black areas can be introduced into one of the printed layers and / or the at least one substrate layer and / or a substrate layer connected to the at least one substrate layer using laser radiation, in order to generate grayscale and black components of the color image. To avoid shadowing and parallax effects, the black components are preferably introduced in the plane of the color patterns or below the color patterns in the at least one substrate layer or in a further substrate layer connected to it.

[0059] To avoid parallax effects, the printed layers with the color patterns are applied with the thinnest possible material. The distance between the printed layers is also preferably minimized.

[0060] In some embodiments, the at least two printing layers are therefore printed directly on top of each other.

[0061] If a thin, preferably transparent, layer is applied or formed between two printed layers, its thickness is preferably minimized. This thin layer serves to separate the color areas and prevent them from mixing during production. The thin layer also offers the additional advantage of simplifying the targeted removal of portions of the color areas without affecting the color areas beneath and / or adjacent to them.

[0062] In addition to or instead of a white-colored substrate layer or printed layer beneath the color patterns, foaming can also be locally generated with laser radiation in at least one substrate layer made of plastic material or in a substrate layer connected thereto, preferably beneath the color image, i.e., on the side of the color image facing away from the viewer. Foamed areas generally scatter light diffusely, so that a white color impression is created when illuminated with white light.

[0063] The invention is explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 a schematic exploded view of a semi-finished product of a data carrier with a color image; Fig. 2. A schematic sectional view of a data carrier of a security document; and Fig. 3. A schematic flowchart for creating a data carrier with a color image.

[0064] In Fig. Figure 1 schematically shows an exploded view of a semi-finished product 10 of a data carrier 20 of a security document 1. The semi-finished product 10 comprises at least one substrate layer 100, which is, for example, a plastic layer. All common materials used for security documents are suitable for the at least one substrate layer 100. In particular, these are plastic materials such as polycarbonate, polyethylene, ABS, PVC, but paper or cotton are also suitable materials.

[0065] Preferably, the at least one substrate layer is made, for example, of filled polycarbonate, which has a white opaque color. Alternatively, the at least one substrate layer 100 can also be made of a transparent or translucent plastic material, for example, polycarbonate. As an alternative to the white coloration, which can be achieved, for example, by filling with titanium dioxide, a transparent polycarbonate layer can be printed with a white print layer on a top surface 101 or, alternatively, on a bottom surface 102. In the Fig. In the embodiment shown in Figure 1, such a white printing layer is missing, since the at least one substrate layer 100 is itself white.

[0066] A printing layer 120 and a further printing layer 140 are printed on the top surface 101 of the at least one substrate layer 100. A color pattern 130, formed from striped color areas 131-133, is printed on the printing layer 120. Each color area 131-133 represents a primary color from a color space. In the illustrated embodiment, these primary colors are, for example, cyan, magenta, and yellow. The colors are in Fig. The colors in figure 1 and the remaining figures are indicated by hatching. Medium-density hatching from the bottom left to the top right indicates cyan, medium-density hatching from the bottom right to the top left indicates magenta, and medium-density horizontal hatching from left to right or vice versa indicates yellow. The orientations are given relative to the drawing plane, where the bottom edge is horizontally aligned. The primary colors are repeated in the color swatch. Color swatch 130 is thus formed by the permutation of the primary colors cyan, magenta, yellow in that order. This permutation is repeated in color swatch 130.

[0067] A center-to-center distance of 136 between adjacent color areas, measured from the center of one color area, for example 131, to the center of an adjacent area, for example 132, is the same for all color areas 131-133. The color areas 131-133 are designed so that they abut each other, forming a closed colored area of ​​a latent image in the color pattern 130. The selected print resolution for creating the color areas 131-133 is preferably chosen such that a human observer at a typical viewing distance of, for example, 20-50 cm does not perceive the color areas as individual areas with a single primary color, but rather perceives a mixed color impression resulting from the color subtraction of the individual color areas.

[0068] The same specifications apply to color sample 150, printed with printing position 140, as to printing position 120 and color sample 130 analogously, except that color areas 151-153 are printed laterally offset from the corresponding color areas 131-133. The center-to-center distances 156 of color areas 151-153 are also the same between adjacent color areas 151 to 153 in color sample 150 and are furthermore identical to the center-to-center distances 136 of color areas 131-133 in color sample 130. It should also be noted that both color samples 130 and 150 are based on the same permutation of the primary colors or color areas of the primary colors cyan, magenta, and yellow.

[0069] In the illustrated embodiment, where the color space is defined by three basic colors or primary colors, namely cyan, magenta, and yellow, and a total of two print layers 120, 140 with a color pattern 130, 150 are printed one above the other onto the at least one substrate layer 100, the color areas 131, 151; 132, 152; 133, 153 of the same color are printed laterally offset from each other by one and a half center distances 136, 155. It should be noted that, due to the perspective exploded view, the individual print layers 120, 140 are shown spaced apart from the substrate layer 100 and from each other along a "layering direction" and laterally offset to the rear and right.

[0070] At the bottom left edge of the Fig. Figure 1 illustrates this. On the left edge of color sample 130, a center line 1310 indicates the center of color area 131 at its edge facing the viewer. Color area 131 is cyan. Another center line 1510 indicates the center of color area 151 at its edge facing the viewer on the left edge of color sample 150. Color area 151 is also cyan. These color areas 131 and 151 are laterally offset from each other in the semi-finished product 10 and security document 1, respectively. Center line 1510 is transformed by means of a projection, represented by an arrow 15, into a secondary center line, also designated with the reference symbol 1510, which is shown as a dashed line. The projection shown by means of arrow 15 compensates for the relative shift chosen for the representation due to the perspective exploded view representation between the superimposed color patterns 130, 150 of 120, 140.The center reference line 1510 indicates the center of color area 151 in the plane in which all the edges of color areas 131, 132, 133 and 151, 152, 153 facing the viewer lie after compensation for the display offset. The lateral offset 1351 in the semi-finished product 10 or security document 1 between center lines 1310 and 1510, corresponding to one and a half center distances 136 between adjacent color areas of color sample 130, is clearly visible. It should be noted again that the center distance 156 between adjacent color areas 151, 152, 153 of color sample 150 is equal to the center distance 136 between adjacent color areas 131, 132, 133 of color sample 130.

[0071] In the illustrated embodiment, when viewed from left to right, the last color area 157 in color pattern 150 is yellow and does not overlap any color area of ​​the first pattern 130. However, this color area 157 could also be the first color area at the left edge 158 of color pattern 150. Even if color pattern 150 then began with a yellow color area, it would still be created based on the same permutation cyan, magenta, yellow, since the entire color pattern 150, except for the edge areas, can be generated using this repeating permutation. A left edge area would then be formed by the yellow color area, and an opposite right edge area by the remaining cyan and magenta color areas. Alternatively, a transparent and colorless material area can also be formed as the end of the color pattern.

[0072] In order to generate a color image with different color impressions from the latent image, which creates a uniform color impression due to color subtraction, parts of color areas 151-153 of the upper color sample 150 and, if necessary, of both color samples 130, 150 are locally and selectively removed by means of laser radiation in order to make different surface proportions of the primary colors or of the at least one white substrate layer perceptible to a viewer, so that, due to the color subtraction or the white color of the at least one substrate layer 100, different mixed color impressions or a white color impression arise at different locations on the semi-finished product 10.

[0073] A white color impression (indicated by the absence of hatching) can alternatively be produced by generating a foam 200 using laser radiation, particularly in a transparent plastic material. This can be used, for example, in embodiments where the at least one substrate layer is transparent. Such foaming can then be carried out, for example, after the targeted removal of parts 180 of the color areas of the color sample 150 and parts of the underlying color areas of the color sample 130 in the at least one substrate layer 100.

[0074] To add black components to the color image, blackening 190, indicated by a very dense horizontal hatching, can also be formed by means of laser radiation in the color areas 131-133; 151-153 and / or the underlying at least one substrate layer 100, after corresponding parts of the color areas 131-133; 151-153 of the color samples 130,150 of the printing layers 120,140 located above it have been removed.

[0075] To manufacture a data carrier from the semi-finished product 10, further processing steps known from the prior art can be carried out. In particular, further security features can be added. Specifically, the semi-finished product 10 is preferably combined with further substrate layers to form a data carrier. This is done, for example, in a lamination process using heat and pressure.

[0076] In the illustrated embodiment, at least one substrate layer 100 is completely covered by the color patterns 130, 150 of the printed layers 120, 140. It is understood by those skilled in the art that the color patterns 130, 150 of the printed layers 120, 140 can also cover only a portion of the substrate layer. Any other security features and elements can be formed and applied to the unprinted areas of the substrate layer.

[0077] The foaming and / or blackening process steps described above can also be carried out subsequently, after the at least one substrate layer 100 has been joined with further substrate layers. The blackening and foaming can also be carried out in these other subsequently added substrate layers.

[0078] In Fig. Figure 2 is a schematic cross-sectional view through a data carrier 20 of a security document 1. Identical technical features are indicated with the same reference symbols in all figures. Furthermore, it should be noted that the representations are merely schematic and, in particular, the material thicknesses of the printing layers 120, 140, 160, as well as the widths and thicknesses of the color areas, are not shown to scale.

[0079] At the in Fig. In the embodiment shown in Figure 2, three printed layers 120, 140, 160 with color patterns 130, 150, 170 are printed one on top of the other onto the at least one substrate layer 100. The color patterns 130, 150, 170 are based on the permutation cyan-magenta-yellow. It is clearly visible that color areas of the three primary colors are printed on top of each other at each point. Also visible are the recesses 205 in the individual printed layers 120, 140, 160, created by the targeted local removal of parts of the color areas. This changes the proportions of the primary colors perceptible to a viewer, thus establishing a locally perceived mixed color impression. Different color impressions are therefore perceived at different locations, which together form the color image.

[0080] Above the printing layers 120, 140, 160, further transparent substrate layers 211, 212 are bonded to the at least one substrate layer 100. These act as protective layers. Additionally, below the at least one substrate layer, i.e., adjacent to the underside 102, further substrate layers 221, 222 are bonded to the at least one substrate layer 100. These are all preferably joined together in a lamination process using pressure and heat to form the data carrier 20 of the security document 1.

[0081] In the lamination process, the recesses 205 are filled by transparent material of the further printing layer 212.

[0082] It is understood by the expert that the number of substrate layers described here is arbitrary.

[0083] In the illustrated embodiment, parts of the color areas are darkened by blackening. Additionally, a foam 200 is formed in the substrate layers 210, 211, which creates a white color impression. Alternatively, this could also be formed in the at least one substrate layer, for example, below the recess 207, which removes parts of all three superimposed color areas 133, 152, 171.

[0084] In Fig. Figure 3 schematically depicts a flowchart of a process for manufacturing a semi-finished product or a data carrier for a security document. First, at least one substrate layer is provided (310).

[0085] Optionally, a white print layer can be printed onto the at least one substrate layer. 320. Dashed lines indicate that this process step is optional. The "c"-like representation indicates that this process step can be performed at different points in the process.

[0086] At least two print layers with a color pattern 330 are printed onto the at least one substrate layer, optionally over the printed white print layer. Each color pattern is composed of color areas that represent the primary colors of a color space. The process step of printing a print layer with a color pattern 330 is therefore performed at least twice, but can also be performed more frequently. If a print layer with a color pattern already exists, the next print layer is printed such that the color areas of the color pattern are laterally offset relative to the color areas of the same color.

[0087] After the layers of ink with the color patterns have been printed, laser radiation is selectively applied to ablate, or remove, parts of the ink areas. This process removes at least parts of the printed layers from the last layer applied, and possibly also from other layers. This locally alters the proportions of the primary colors perceptible to the viewer, allowing the perceived color to be varied locally through color subtraction or addition. This creates a color image.

[0088] To form a data carrier, further substrate layers, in particular one or more transparent substrate layers that cover and enclose the color patterns, are usually bonded to the at least one substrate layer. This process step can also be carried out at different points in the process.

[0089] Blackening can also be carried out in parts of the color areas, the at least one substrate layer or possibly further substrate layers connected to it, by means of laser radiation 360, in order to create black components of a color image.

[0090] Optionally, in particular if the at least one substrate layer is not itself white or is not printed with a white print layer and no other white substrate layer is connected to the at least one substrate layer on the side facing away from the print layers with the color pattern, white components can be added by local foaming using laser irradiation 370.

[0091] A color image created by superimposing color patterns and selectively removing certain areas using laser radiation can be reliably distinguished from printed color images. Semi-finished products, data carriers, and security documents with color images created by superimposing color patterns and then partially removing them with laser radiation are much more difficult to counterfeit or imitate than data carriers with printed color images. To create the various printed layers with the color images in such a way that the color areas are correctly offset laterally and yet printed with high spatial resolution—in order to produce sharp, high-resolution color images using laser radiation—very precise printing processes are necessary, requiring a high level of expertise in the field of printing. Counterfeiters often lack this expertise.Furthermore, it is necessary to very precisely remove specific parts of colored areas using laser radiation. This is possible through the precise adjustment of the laser's energy and focus, without also removing underlying colored areas, unless desired. Since the colored areas are removed before any protective layers are applied, subsequent manipulation using targeted laser radiation is either impossible or at least easily detectable. This is because, if laser radiation were used to manipulate parts of superimposed printed colored areas, even if they could be selectively removed, this would typically result in noticeable clouding of the overlying transparent substrate layers.

[0092] It will be apparent to a person skilled in the art that only exemplary embodiments of the invention are described. Reference symbol list 1 Security document 10 semi-finished products 15 Arrow 20 data carriers 100 substrate layer 101 Top 102 Subpage 120 pressure position 130 color samples 131 - 133 color ranges 136 Center-to-center distance 140 more pressure layers 150 color samples 151 - 153 color ranges 156 Center-to-center distance 157 last color range 158 left edge 160 pressure position 170 color samples 171 - 173 color ranges 180 locations where parts of a department have been removed 190 blackenings 200 Foaming 205 Exclusion 207 Exclusion 211 - 212 substrate layers 221 - 222 substrate layers 300 Flowchart 310 Provide at least one substrate layer 320 prints of a white print layer 330 prints of at least one print layer with a color pattern 340 Beaming of laser radiation to remove parts of the color areas 350 Laminating at least one substrate layer with further substrate layers to form a lamination body 360° laser beam projection to generate black and / or grey image areas (blackening) 370 Irradiation of laser radiation to generate foams 1310 midline 1510 midline 1351 lateral offset of the center lines of similarly colored color areas of superimposed color patterns

Claims

[1] Method for producing a data carrier (20) of a security document (1) with a color image, comprising the steps: Providing at least one substrate layer (100); Printing of at least two printing layers (120, 140, 160), wherein each of the at least two printing layers (120, 140, 160) has a color pattern (130; 150; 170) which comprises differently colored color areas (131-133; 151-153; 171-173), wherein the differently colored color areas (131-133; 151-153; 171-173) have basic colors which together span a color space, wherein color areas (131-133; 151-153; 171-173) of the color patterns (130; 150; 170) of printing layers (120, 140, 160) printed on top of one another are laterally offset, irradiating laser radiation for the local removal at different positions of at least parts (180) of Color areas (131-133; 151-153; 171-173) of the color pattern (130; 150; 170) or the color patterns (130; 150; 170) of the at least two printing layers (120, 140, 160), so that due to color addition or color subtraction due to the remaining and / or exposed portions of the color patterns (130; 150;170) different color impressions are created at different places, which together form the color image.; [2] Method according to claim 1, characterized by that the at least two printing layers (120, 140, 160) are printed in such a way that the color patterns (130; 150; 170) of the at least two printing layers (120, 140, 160) have the same sequence or the same sequences of color areas (131-133; 151-153; 171-173) with respect to a distinguished direction. [3] Method according to one of the preceding claims, characterized by that the color patterns (130; 150; 170) are all formed based on a permutation of color areas (131-133; 151-153; 171-173) with the primary colors of the color space. [4] Method according to one of the preceding claims, characterized bythat the color samples (130; 150; 170) are printed by means of the two printing layers (120, 140, 160) in such a way that a center distance of adjacent color areas (131-133; 151-153; 171-173) within the respective color sample (130; 150; 170) is the same and between the color samples (130; 150; 170) of the at least two printing layers (120, 140, 160) is identical. [5] Method according to claim 4, characterized byin that the center positions of the color areas (131-133; 151-153; 171-173) are offset laterally along the marked direction by a distance relative to center positions of corresponding specialized areas (131-133; 151-153; 171-173) of the color pattern (130; 150; 170) of the immediately previously printed one of the at least two printing layers (120, 140, 160), the distance resulting from the product of the center distance of adjacent color areas and a quotient which is formed from the number of different primary colors of the color space and the number of at least two printing layers (120, 140, 160) with a color pattern (130; 150; 170). [6] Method according to one of the preceding claims, characterized by that the at least one substrate layer or a layer connected to the at least one substrate layer on the side facing away from the side onto which the at least two printing layers (120, 140, 160) are printed is white or diffusely remitting. [7] Method according to one of the preceding claims, characterized by that at least one transparent cover layer, which covers and encloses the color patterns (130; 150; 170), is connected to the at least one substrate layer (100) by means of the laser radiation after the removal of at least parts of color areas (131-133; 151-153; 171-173) of the color pattern (130; 150; 170) or the color patterns (130; 150; 170) of the at least two printing layers (120, 140, 160). [8] Method according to one of the preceding claims, characterized by that additional blackenings are introduced into one of the printing layers (120, 140, 160) and / or the at least one substrate layer and / or a layer connected to the at least one substrate layer by means of laser radiation in order to produce greyscale and black components of the colour image. [9] Semi-finished product (10) for producing a security document (1) with a color image comprising at least one substrate layer (10); at least two printing layers (120, 140, 160) printed one above the other on the at least one substrate layer (100), wherein each of the at least two printing layers (120, 140, 160) has a color pattern (130; 150; 170) which comprises differently colored color areas (131-133; 151-153; 171-173), wherein the differently colored color areas (131-133; 151-153; 171-173) have basic colors which together span a color space, wherein color areas (131, 151, 171, 132, 152, 172, 133, 153, 173) of the color patterns (130; 150; 170) of printing layers (120, 140, 160) are laterally offset. [10] Semi-finished product (10) according to claim 9, characterized bythat at least parts of color areas of the color pattern (130; 150; 170) or of the color patterns (130; 150; 170) of the at least two printing layers (120, 140, 160) are removed by means of laser radiation at different positions, so that due to color addition or color subtraction due to the remaining and / or exposed portions of the color patterns (130; 150; 170) at different locations, different color impressions are generated, which together form the color image. [11] Data carrier (20) of a security document (1) with a color image comprising a semi-finished product according to claim 9 or 10.

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