DE10361131A1 - Security element for security papers and value documents - Google Patents

Abstract

The invention relates to a security element for security papers and value documents, such as banknotes, passports, identity documents or the like, wherein the security element has a color-coded latent image with different image proportions.

Description

The Invention relates to a security element for security papers and value documents, like banknotes, passports, Cards, identity documents or the like, with at least one color coded latent image, the color coded latent image being different Has image parts. The invention further relates to a security paper and a value document with such a security element.

Under Security paper is hereinafter understood to mean paper which is e.g. already with security features such as watermarks, security thread, hologram patch etc., but is still fit for circulation and intermediate in the production of the value document is. Under value document becomes the recyclable product understood, e.g. the printed banknote.

Documents of value, such as banknotes, stocks, bonds, certificates, vouchers, Checks, high-quality tickets, but also other counterfeit papers, like passes, Cards or other identity documents are used to increase their counterfeit protection equipped with various security features. For a long time be in this context z. B. watermark as a security feature used. Watermarks have the special property that they only become visible in transmitted light while visually in reflected light are difficult to perceive.

Also by printing security paper can be a value document equipped with security features. Using the example of passport documents let yourself clarify that by the process of printing a series of value documents with identical security features can be. In addition, however, any value document with a be provided individual security feature. A series of passports can z. B. with a single, d. H. everywhere identical picture motif be equipped but at the same time individualized. The term "individualization" of passports is understood the equipment of each individual passport with an individual picture, z. B. a portrait of the owner.

To the Printing on security paper is basically both on additive color mixing as well as on subtractive color mixing based printing processes or prints. In offset, gravure or Thermal transfer printing produces colored halftone prints in which the color shades are reproduced by means of dot patterns become. The color impression is created by a subtractive and additive color mixing of three primary colors, namely cyan, magenta and yellow. The pigments of printing inks absorb from the incoming white light the respective complementary part their own color. The unabsorbed portion of the white light is reflected, reaches the eye of the beholder and calls there produce a color impression, the natural color of the respective printing ink is felt. Each of the primary colors thus reflects only one Part of the incoming light. Because the 100% blend of printing inks Cyan, magenta and yellow not black, but dark brown, almost all printers use black as an additional color (four-color printing).

On a screen such. B. a television tube, however, images are exclusively by additive color mixing produced. It represents, so to speak, every point on the television tube a small light source that shines in a special color. Be it, as is the case with the TV tube, for example, three areas of the visible spectrum are selected as colored light sources which are transmitted via the entire area of the visible spectrum are distributed and the corresponding color receptors in the eye are able to stimulate (z. B. red, green, Blue-violet), it is possible by additive color mixing images to produce with true-to-life color representation.

After this a requirement for the additive color mixture the presence correspondingly more luminous Pixels is, you have so far on the use of the additive To dispense with color mixing in printed halftone images. In recently, However, some efforts have been made to additive color mixing also with printed halftone pictures for the equipment of value documents to establish with security features.

So will in the DE 10136252 described a colored halftone image having at least two types of grid-like pixels of different colors. These different colors also contain fluorescent pigments. Preferably, three different printing inks are used, the pigments of the different printing inks each fluorescing in one of three primary colors (eg red, green, blue-violet) and thus producing additive color mixing. A personnel document can z. Example, are provided by a portrait of the document holder is provided, which is printed as a halftone image with normal inks, while a second portrait is provided by the additive color mixing produced under UV light fluorescent, pigmented ink. These two images can be placed side by side on the document.

In the US 6,155,168 It also describes a personal document that includes a visually-visible photo portrait and a photo portrait printed with UV-fluorescent inks.

These Safety elements described in the prior art are incorporated in recently, Past but more often and better by counterfeiters imitated. Since today the necessary printing inks and also fluorescent Colors readily available in the market are, the known security elements do not provide sufficient Protection against counterfeiting of value documents.

Of the The invention is therefore based on the object, a security element to provide that avoids the disadvantages of the prior art. In particular, the counterfeit security security papers and documents of value.

These Task is characterized by the security element with the characteristics of Main claim solved. A security paper, a value document, the use of security elements for the production of security paper and a method of manufacture of printed surfaces are the subject of the independent claims. Advantageous developments The invention are the subject of the dependent claims.

Of the The invention is based on the finding that the security against counterfeiting of security papers and value documents through security elements can be improved, which has a color-coded latent image with different Have image shares.

The The present invention therefore relates to a security element for security paper and value documents, such as banknotes, passports, cards, identity documents or the like, wherein the security element is a color-coded Has latent image with different image proportions.

Under the term "latent image" is understood to mean an image the usual Illumination visually not or at least only very badly perceptible is while it using special technical aids such. B. lighting becomes visually visible with a UV or IR light source.

One So latent image can be in the desired Color can only be observed when there is electromagnetic radiation appropriate wavelength is irradiated. As a result, the color of the latent image changes when an irradiation with light of different wavelengths, for example on the one hand with visible light, on the other hand with ultraviolet Light, done. This way you can on a security paper different entities are displayed, depending on the wavelength of the for the Lighting used electromagnetic radiation alternately are visible.

Becomes hereinafter referred to as "normal" or "normal" lighting, such is a lighting with natural or artificial Light in the visible wavelength range to understand. Used by a lighting with a UV light source spoken, so is an extra Lighting with UV light meant, so z. B. the use of a UV lamp in daylight.

Under a "picture" generally becomes one understood visually and / or machine readable information. among them fall both photorealistic representation as well as line motifs, So abstract representations. Photorealistic representations are for example, portraits (eg of a head of state), landscape motifs, animal motifs and buildings. Due to the increased Image information leads a photorealistic representation to a much improved Identification or recognizability for the viewer. At abstract Representations are z. Eg coats of arms, buildings, flags, Patterns, characters and encodings, all in perspective as well as in area Presentation can be provided.

Under a luminescent substance is understood as a chemical compound which is capable of emitting luminescent light upon excitation with light. Luminescent substances (luminescent dyes) can be light in a wavelength range from the ultraviolet (UV) over absorb the visible (VIS) to the infrared (IR) region. The emission can follow Stoke's or Anti-Stoke's law.

An "IR absorber" is understood as meaning a chemical compound which, in the infrared spectral range between 800 nm and a few μm, has at least one absorption with a high absorption coefficient such as ADS 880 MC (C ₃₂ H ₂₈ S ₄ Ni) from Siber Hegner, absorption maximum at 880 nm.

The Luminescence is usually divided into fluorescence and phosphorescence, the basis lying physical process is the same, namely the Emitting electromagnetic radiation when returning a molecule from an electronically excited state in the electronic Ground state. The difference between fluorescence and phosphorescence lies only in the lifetime of the excited states and thus in the duration of luminescence after completion of the excitation of luminescent compound. Fluorescence is through a lifetime of the excited state in the range of picoseconds to microseconds marked while one of phosphorescence with a lifetime in the millisecond range and longer speaks.

By the interaction of three luminescent primary colors (red, green, blue-violet) can by additive color mixing a visible under UV light, multi-colored image that is not under normal lighting is identifiable. In photorealistic representations, the aim is that the color of the subjects under UV light largely the Color of a color photograph of the imaged object corresponds. For example, the portraits applied to passport documents the respective owner as accurately as possible the color information of the usual Play passport photo. Abstract motifs become striking as line motifs shown multicolored luminescent. The luminescent colors of Individual elements should correspond to the basic color of the original. The multicolor becomes the identification and recognizability for the Viewer improves.

In In this context, it should be emphasized that all types of security elements according to the invention in various forms can be applied to security papers and documents of value. So can z. As the individual letters of any text with different luminescent Connections or colors are printed. When illuminated with UV light The individual letters then appear differently colored. Of the same text can z. B. also be printed several times, where each used different luminescent compounds become. Under a UV source, the text then appears several times in each different color.

Becomes, as described below, the use of luminescent compounds with the use of already visually perceptible under normal lighting Combined inks, so can z. B. shadow effects are caused. This is z. B. a any text printed with the help of luminescent compounds and the identical text then slightly offset to this again with normal Applied printing inks. In UV illumination then appears the luminescent Text as a "shadow" of the normal printed Text.

When other examples are a text or individual letters or Figures called, some with luminescent compounds and be printed in part with normal printing inks. With usual lighting are then only fragments of the text, the letters or the figures, which are then under UV illumination Completely become visible.

It it is again pointed out that this list is not finally is, but that the security elements according to the invention in any shape can be printed.

In especially easier and cheaper Way, a color coded latent image with different image parts by using luminescent substances and / or IR absorbers be generated. Both luminescent and IR absorbers have the property on that they visually not under usual lighting or at least only very badly perceptible while they are under illumination with a UV light source or with lighting an IR light source give a visually perceptible image. The different image components of the color-coded latent image can by various luminescent compounds, by different IR absorbers or formed by mixing of luminescent compounds and IR absorbers become.

Special Advantages regarding the forgery security arise when both luminescent and IR absorbers present are. The entire security element can namely only in this case by simultaneous illumination with a UV light source and a IR light source are perceived.

For example, it is possible in this way to provide a personal document in two ways with the portrait of the document owner, wherein the first portrait is represented by IR absorber, while the second portrait is produced by luminescent compounds. In this way, the Si safety of a personal document and at the same time it provides a simple method of authenticity. It merely has to be checked whether the portrait of the document owner produced by IR absorption agrees with the portrait resulting from additive color mixing of luminescent colors.

Special Benefits result from the combination of one or two fluorescent Substances with one or two IR absorbers. The absorption maxima the IR absorber advantageously differ by at least 20 nm. The information encoded by the different substances be z. B. by scanner or CCD camera with different Edge filters are read and with a downstream image processing program evaluated. This makes the information an easily interpretable, multi-color image or two complementary images added. The Single colors can with the control instruments known from the prior art, such as B. UV hand lamp and IR converter camera checked become.

Next The better identification of the value documents is provided by the security elements the forgery of the present invention of value documents made much more difficult. Due to the complexity of color systems, the need for a suitable color management system and a suitable trade fair equipment for the quality inspection of Pressure is the hurdle for potential counterfeiter clearly increased. Furthermore, the production of color separations by means of reproduction technology extremely expensive and requires a lot of experience as well as technical equipment for Realization by a potential counterfeiter.

to Excitation of the luminescent pigments can be the most diverse Types of electromagnetic radiation can be used. In practice however, it will generally be convenient to use pigments which fluoresce under the influence of UV radiation.

According to preferred embodiments The present invention uses the various parts of the picture of the security element by at least 3 fluorescent substances formed, wherein the fluorescent substances either at a wavelength of 254 nm can be excited to fluorescence or at a wavelength of 254 nm and at one wavelength of 366 nm can be excited to fluorescence. Special benefits arise namely, when the different image parts of the security element go through at least 3 fluorescent substances are formed, wherein at least one of the fluorescent substances at a wavelength of 366 nm and 254 nm can be excited to fluorescence and additionally at least one of the fluorescent substances only at a wavelength of 254 nm can be excited to fluorescence.

When example for this embodiment can be called a combination of 3 fluorescent substances be with the blue emitting substance both at 254 nm as also excitable at 366 nm while the yellow or red emitting substances excitable only at 254 nm are. By the usual used excitation sources, the UV radiation of a wavelength of 366 nm, then only a blue emission is generated. If, however, a switchable to 254 nm UV source is used, so the security element becomes recognizable as a colored motive, which itself composed of the emission of the colors red, yellow and blue. Thereby becomes the counterfeit security clearly increased.

Examples for luminescent Compounds used in printing inks to produce the color-coded invention Latent images are used are:

Bi-fluorescent materials

• Honeywell / Seelze CD-R / GL: yellow emission after stimulation with short-wave UV light (254 nm) red emission after stimulation with long-wave UV light (366 nm)
• R / G CD770 from Honeywell / Seelze: orange emission after stimulation with short-wave UV light (254 nm) green-yellowish emission after excitation with long-wave UV light (366 nm)

Phosphorescence materials

• Lumilux Green N2 from Honeywell / Seelze
• Lumilux Green CD 111 from Honeywell / Seelze

IR-emitting luminescent substances

• IR-CD 139 from Honeywell / Seelze: Near IR emission after excitation with UV light

Anti-Stokes materials

• Green UC2 from Honeywell / Seelze: green emission in the VIS range after excitation with IR light
• Red UC6 from Honeywell / Seelze: red emission in the VIS range after excitation with IR light
• Blue UC6 from Honeywell / Seelze: blue emission in the VIS range after excitation with IR light

• Luminescent or fluorescent substances (from Honeywell / Seelze) CD 380: red emission after excitation with short or long wave UV light CD 145: red emission after excitation with short-wave UV light CD 797: green-yellowish emission after excitation with short or long wave UV light CD 112: green emission after excitation with short-wave UV light CD 329: blue emission after excitation with short or long wave UV light CD 165: blue emission after excitation with short-wave UV light

Examples of IR absorbers used in printing inks to produce the color-coded latent images of the invention are:
ADS 880 MC (C ₃₂ H ₂₈ S ₄ Ni), absorption maximum at 880 nm from Siber Hegner.

Special Advantages regarding the forgery security arise when the security element by three fluorescent Substances and an IR absorber is formed. The fluorescence of the visually invisible substances can be detected with the help of a UV hand lamp or a UV / IR scanner be while the IR absorption z. B. be determined by an IR converter camera can. A comparison of the image data from the fluorescence or IR measurement provides an excellent test of the authenticity of the value document represents.

According to others preferred embodiments The present invention uses the various parts of the picture the color-coded latent image by phosphorescent substances formed or it will be in the security element one or more replaced fluorescent substances by phosphorescent substances or are additional one or more phosphorescent substances present. So can z. B. a yellow fluorescent substance by a yellow phosphorescent Connection to be replaced. In the presence of image parts, the on the one hand fluoresce and on the other phosphoresce, lie thus parts of the picture that linger for different amounts of time. With naked Eye is the different afterglow not recognizable, however, using a sensor very well. An adjustment exclusively with fluorescent substances is so easily distinguishable from the original. Thus, by combining fluorescence and phosphorescence integrated another detectable security feature that with a Simple UV lamp and visual inspection with the naked eye can not be detected, but only by using a corresponding Sensor.

Particular effects can be achieved if the different image components of the color-coded latent image are formed by bi-fluorescing substances or if at least one bi-fluorescent substance is additionally used in the security element. These compounds fluoresce when exposed to radiation of different wavelengths in different colors. Depending on the radiation used to illuminate the color-coded latent image, a different image is obtained, depending on the color in which the bi-fluorescent substance illuminates. Depending on the wavelength used for the irradiation, color changes and also changes in the motif can be achieved. By using one or several bi-fluorescent substances can be detected in short-wave UV light, for example, more image information. In a concrete embodiment, for example, a portrait image is printed with three different fluorescent substances. When irradiated with long-wave UV light, substance 1 and substance 2 emit yellow light, substance 3 yellow-greenish light. Upon irradiation with short-wave light, substance 1 emits red light, substance 2 blue light and substance 3 yellow-greenish light.

at Irradiation with long-wave UV light, usually of simple UV hand lamps is emitted, the portrait picture appears to the Viewer monochrome while when excited with short-wave light the multicolor, ideally the one similar to a color photograph Picture becomes visible. It can Also substances are used where the reverse effect is visible Thus, when irradiated with long-wave UV light is a multicolor Luminescence image and short-wave UV light a monochrome luminescence image visible, noticeable.

According to one another embodiment are the image components of the security element by at least 3 IR absorber formed, with the IR absorber on absorption maxima which differ by at least 20 nm. Prefers is the difference is at least 50 nm, more preferably at least 100 nm.

When example for the described embodiment can be the combination of a substance with an absorption maximum at 800 nm, a substance with an absorption maximum at 900 nm and a substance with an absorption maximum at 1000 nm called become. The amount of each substance present and thus their absorption intensity corresponds to the intensity one of the basic colors blue, red and green. So z. B. the substance with absorption maximum at 800 nm the image data for the blue extract, the substance with absorption maximum at 900 nm, the image data for the red extract and the substance with absorption maximum at 1000 nm the image data for the Green Abstract contain. Through a scanner with 3 scanning units or edge filter for the Separation of image data and a downstream image processing program the information becomes an easily interpretable color image, such as B. a portrait processed.

According to one another embodiment of the present invention the security element in addition at least one among usual Lighting visually visible color. In particularly advantageous Way you can one or more fluorescent substances with one or more Visually visible substances are combined. As an example called the use of three different substances, wherein z. B. a substance in the visible light appears red and at the same time fluoresces red under UV light. Another substance fluoresces yellow under UV light and appears white in visible light, while the third substance under UV light fluoresces blue and visible Light also appears white. The combination of these three substances shows that in the visible light a red image appears while under UV light through the yellow, blue and red fluorescent image parts a photographic Image becomes visible in true colors.

One Another example of a combination of one or more fluorescent Substances with one or more visually visible substances represents an embodiment in which a visually visible color as a contour (eg Line drawing) for the visually invisible fluorescent substance (s) serves. The Visually visible colors and the fluorescent substances are accurate printed to each other. For example, as a contour color, black (e.g. For example a portrait) in combination with three different colors visually not visible fluorescent substances are used. advantageously, For example, the portion printed with visual visible color becomes software-related in the for a true color representation in the luminescence image necessary color component converted and then a corresponding true color image computationally generated.

One another example of the combination of one or more fluorescent substances with one or more under usual Lighting visually visible substances represents a grayscale image that is accurate to one or more of the usual Lighting invisible fluorescent fabrics is printed. The grayscale image corresponds to the information "paper white" or the negative separation of one or several fluorescent substances.

The Visualize latent images whose different image parts from under usual Illumination of visually invisible colors and fluorescent substances exist, by UV hand lamp, scanner or CCD camera.

Particular preference is given to security elements which additionally contain magnetic substances and / or electrically conductive substances. These additional feature substances on the one hand the Fäl increased security and provided on the other another way to encode information. If the security element is imprinted by an inkjet, the magnetic substances and the electrically conductive substances consist of particles which have an average size in the nanometer range.

Besides can also one or more fluorescent compounds by one already Under normal lighting visually visible color replaced and accurate be printed for image information of the fluorescent substances. The visualization takes place in this case by means of scanner / CCD camera, the proof is using a downstream image processing software made.

to Production of a security paper with a security element according to the invention is the respective image portion of the security element by software technology Preparation of the corresponding image information for printing prepared. The proportions of luminescent substances to be used are determined by means of a color management system and in one Grid, preferably a beam and honeycomb grid, optionally with Negative contour lines printed. Especially with striking picture elements Negative contour lines can increase the contrast and therefore the contrast improved and faster image or scene recognition can be achieved. The image or the image information can after printing by means of IR converter cameras or scanners are verified.

As already mentioned, different value documents, such as passport documents, next to one for a whole series of documents identical security feature in addition with equipped with an individual security feature. A series of passports can z. B. with an identical image and at the same time with be provided with the portrait of the respective owner. The security elements according to the invention are suitable for both types of security features, both for the a series of documents identical elements, as well as individual Pictures in the personalization of documents.

For example can fluorescent substances (with and without additional features, such as IR absorbers, magnetizable, electrically conductive or anti-Stokes pigments) in offset printing or other non-impact method in a given Area of the security paper or document of value. By a registration-accurate personalization (eg by an inkjet printer) be partial information for one Series of documents covering uniformly applied security elements. When illuminated with UV light, the individual security element, So z. B. a single or multi-colored portrait, visible. By the Combination of the different printing processes results in an increased protection against counterfeiting.

For example can on a series of passport documents adjacent thin strips in the fluorescent colors red, green and blue are printed and then partially overprinted with a black and white portrait of the passport holder become. The black color of the portrait has the property the fluorescent radiation emitted by the strips under UV illumination to absorb. Under normal lighting conditions, that's just that Black / White Portrait visible, when irradiated with UV light then the fluorescent Strips only visible in areas where no black Color is printed. Alternatively it could be to the black color Also, a UV-absorbing, invisible color can be used. In this case would be in normal light no information can be recognized. When illuminated with UV radiation would be again only fluorescent stripes visible only in the areas, in where the UV-absorbing ink is not printed. With UV-absorbing ink printed information would be so to speak recognizable as a negative in the fluorescent striped pattern. In a preferred variant are the red, green and blue fluorescent Stripes designed so narrow that the eye strips the individual no longer dissolving, but due to additive color mixing a monochrome, preferably perceives white area. About that becomes a raster technique in the spectral range of fluorescent colors absorbent material printed. About the grid element size can now be controlled which fluorescence color component is absorbed and which penetrates the eye. A white under UV illumination Raster element is thus completely Absorbent while an element appearing black in the picture is completely overprinted. Accordingly arise - ever after which strips are covered with the absorber or not - the corresponding ones Mixed colors for the eye. Ideally, the viewer sees a fluorescent True color image, the black portion of which was generated by an absorber was printed in suitable raster elements.

In a further variant, an area with luminescent substances is completely printed. This surface is then overprinted, for example, with a portrait of the passport holder with ink which absorbs in the region of the emission of the luminescent substance. Under UV light, for example, yellow fluorescence is seen in the non-overprinted border area, while in the portrait area, in turn, fluorescence is only there is acceptable, where no pressure color is used. Under UV light you can see a negative, fluorescent portrait.

The The invention also includes a value document, such as a banknote, a Share, a check, a passport, a document of identification, a visa, an ID card, in particular paper-based, or the like, which is a security element of has described type.

From The invention also encompasses the use of security elements for the manufacture of security paper, the security elements have a color-coded latent image with different image parts.

From The invention also includes a security paper, wherein the Security paper at least one security element with a color-coded Has latent image with different image proportions.

The The present invention also includes a method of preparation of printed with luminescent substances and / or IR absorbers surfaces, in particular for the production of printed security papers and value documents, by a screen printing method, wherein it is in the screen printing method by a bar screen printing method or is a honeycomb screen printing method.

By the application of a beam or honeycomb raster printing process can be used in the Compared to the known from the prior art conventional Raster printing methods, such as dot and grain screen printing, essential higher-contrast, cleaner image representations can be achieved.

Especially Bar raster printing methods as well as honeycomb raster printing methods are suitable for printing color-coded latent images with different image proportions in all variants described above. It is particularly preferred in this Context, when the different parts of the picture of the color-coded Latent image by fluorescent substances, by phosphorescent Substances, by bi-fluorescent substances, by IR absorbers or by combination of these substances.

at Application of the known from the prior art point and Kornrasterdruckverfahren comes it leads to significant intensity losses when printing mixed colors, which consist of at least two different Compose luminescent substances. With the help of the bar and honeycomb grid can the colors approximate 100% printed side by side.

in the Trap of the bar raster becomes the type and intensity of the visually perceived Mixed color over the glowing surfaces the individual colors controlled. The mixed color changes depending on the intensity of the individual colors. For this reason, a square grid structure becomes special preferred, wherein the square into three equal strip-shaped sections is divided. The intensity the individual colors and thus the visually visible color impression, ie the mixed color results from the "fill level" of the individual fields.

Also in the case of the honeycomb grid, the type and intensity of the visual perceived mixed color over the glowing surfaces the individual colors controlled. The perceived by the viewer Mixed color changed also here depending on the intensity the individual colors. The intensity the individual colors and thus the visually visible color impression, ie the mixed color results from the different area coverage the single colors in the honeycombs.

Preferably Rule widths of 20, 36 or 60 lines per cm are used. The width and height of a Raster cell is preferably 0.5 mm and less, preferably 0.2 mm and less. By the beam of the invention and honeycomb printing method may advantageously additionally at least a visually visible under normal lighting color, in addition at least a magnetic substance and / or additionally at least one electrical conductive Substances are printed.

embodiments The invention will be explained below with reference to the figures. to better vividness is in the figures on a scale Presentation omitted.

It demonstrate:

1 a plan view of a passport document according to an embodiment of the invention in a schematic representation of conventional lighting,

2 a supervision on the in 1 shown passport document with additional illumination with a UV light source,

3a - 3c Beam grid cells and

4a - 4c Honeycomb grid cells.

1 shows a schematic representation of a passport document 10 according to an embodiment of the invention when illuminated with daylight. The front of the passport 10 contains a passport photograph printed with normal inks 12 the owner, as well as in machine-readable form further personalized information 14a to 14f including the name 14a of the holder, an identification number 14b , the exhibition venue 14c , the date of birth of the owner 14d , the date of issue of the passport 14e and the validity period of the passport 14f contain.

2 shows that in 1 Passport document shown with additional illumination with a UV light source. In addition to the respect 1 information described will be another portrait 22 of the passport holder printed with fluorescent substances on the passport document. When using three luminescent substances, each emitting in one of three primary colors (eg, red, green, blue-violet), a largely lifelike image of the passport photograph 12 of the holder. The match of passport photo 12 and fluorescent portrait 22 is an easily verifiable feature for the authenticity of the document and significantly increases the security against counterfeiting.

3a shows a grid cell of the bar grid, wherein the cell preferably has a rectangular shape, most preferably a square shape. The cell is in three equal, strip-shaped sections ( 22 . 23 . 24 ), which are associated with three differently luminescent color areas and preferably fluoresce red / blue or yellow. Provided additive color mixture, the in 3a shown cell with full-surface printing the color impression white.

3b also shows a grid cell of a bar raster, here the strip-shaped sections 22 . 23 and 24 only partially printed. Depending on the area fraction and intensity of the luminescent substance, a corresponding mixed color results for the eye in question.

3c shows a beam grid cell in which the sections 22 . 23 and 24 are not printed and thus deliver the color impression black to the eye.

In 4a a grid cell of the honeycomb grid is shown. A cell preferably appears as the two-dimensional image of a cuboid, most preferably as the two-dimensional image of a cube, each of which three sides are visible. These three pages 32 . 33 . 34 are analogous to the strip-shaped sections 22 . 23 and 24 in the 3a to 3c to see. In 4a are the surfaces 32 . 33 and 34 again filled with three different luminescent substances over the entire surface, so that the impression of a white cell results under UV light for the human eye with additive color mixing.

4b shows the same cell, wherein the surface portions which occupy the different luminescent substances, turn out differently sized and thus produce a mixed color under UV light.

In 4c the honeycomb grid cell is not printed so that it produces the color impression black under UV light for the human eye.

Claims (34)

A security element for security papers and documents of value such as banknotes, passports, identification documents or the like, characterized net gekennzeich that the security element has a color coded latent image with various image portions. Security element according to claim 1, characterized in that that the image components of the color-coded latent image by different luminescent substances and / or by different IR absorbers be formed. Security element according to claim 2, characterized in that that the luminescent substances are fluorescent Substances act. Security element according to claim 2, characterized in that that the luminescent substances are phosphorescent Substances act. Security element according to claim 2, characterized in that that the luminescent substances are bi-fluorescent Substances act. Security element according to claim 2, characterized in that that the image portions are formed by at least three IR absorbers are, with the IR absorber absorption maxima, which is by at least 20 nm, preferably at least 50 nm, more preferably at least 100 nm. Security element according to claim 3, characterized that the image portions by at least three fluorescent substances are formed, wherein the fluorescent substances are preferred by electromagnetic radiation of a wavelength of 254 nm for fluorescence can be stimulated. Security element according to claim 3, characterized that the image portions by at least three fluorescent substances are formed, wherein the fluorescent substances by electromagnetic Radiation of a wavelength of 254 nm and by electromagnetic radiation of a wavelength of 366 nm can be excited to fluorescence. Security element according to claim 3, characterized that the image portions by at least three fluorescent substances are formed, wherein at least one of the fluorescent substances electromagnetic radiation of a wavelength of 254 nm and by electromagnetic Radiation of a wavelength of 366 nm can be excited to fluorescence, and at least one of the fluorescent substances only by electromagnetic Radiation of a wavelength of 254 nm can be excited to fluorescence. Security element according to at least one of claims 7 to 9, characterized in that one or more fluorescent Substances are replaced by phosphorescent substances. Security element according to at least one of claims 7 to 9, characterized in that in addition one or more phosphorescent Substances are present. Security element according to at least one of claims 7 to 11, characterized in that one or more fluorescent Substances are replaced by bi-fluorescent substances. Security element according to at least one of claims 7 to 11, characterized in that additionally at least one bi-fluorescent Substance is present. Security element according to at least one of claims 7 to 13, characterized in that one or more fluorescent Substances are replaced by IR absorbers. Security element according to at least one of claims 7 to 13, characterized in that in addition at least one IR absorber is present. Security element according to claim 15, characterized that at least two IR absorbers are present, wherein the IR absorbers Have absorption maxima that are at least 20 nm, preferred at least 50 nm, more preferably at least 100 nm, distinguish. Security element according to at least one of claims 1 to 16, characterized in that the security element additionally at least contains a visually visible color. Security element according to at least one of claims 1 to 17, characterized in that the security element additionally magnetic Contains substances. Security element according to at least one of claims 1 to 18, characterized in that the security element in addition electrically conductive Contains substances. Security paper for the production of value documents, like banknotes, passports, Identification documents or the like, characterized in that the security paper at least one security element according to at least one of the claims 1 to 19. Value document, such as banknote, passport, identity document or the like, characterized in that the value document at least one security element according to at least one of claims 1 to 19 has. Use of security elements as in claims 1 to 19 defined for the production of security paper. Process for the preparation of luminescent Substances and / or IR absorber printed areas, especially printed Security papers and documents of value through a halftone printing process, namely a bar screen printing method or a honeycomb screen printing method. Method according to claim 23, characterized that the bar grid is constructed from a square grid structure is. Method according to Claim 24, characterized that the square grid consists of three equally sized strip-shaped segments consist. Method according to at least one of claims 23 to 25, characterized in that a color-coded latent image with different image portions is printed. Method according to claim 26, characterized in that that the different image parts of the color-coded latent image by fluorescent substances, by phosphorescent substances, by bi-fluorescent substances, by IR absorbers or by Combinations of these substances are formed. Method according to at least one of claims 23 to 27, characterized in that additionally at least one visually visible color is printed. Method according to at least one of claims 23 to 28, characterized in that additionally at least one magnetic Fabric is being printed. Method according to at least one of claims 23 to 29, characterized in that additionally at least one electrically conductive Substances is being printed. Printed image composed of individual grid elements is, characterized in that the grid is a honeycomb grid. Printed image composed of individual grid elements is, characterized in that the grid is a bar grid. Printed image according to claim 31 or 32, characterized that the grid element consist of at least three subelements, which are printed with different luminescent colors. Printed image according to claim 33, characterized that the sub-elements partially not printed over the entire surface or proportionately are.