EP0858400B1 - Document with a moiré-effect-generating screen structure - Google Patents

Document with a moiré-effect-generating screen structure Download PDF

Info

Publication number
EP0858400B1
EP0858400B1 EP97940149A EP97940149A EP0858400B1 EP 0858400 B1 EP0858400 B1 EP 0858400B1 EP 97940149 A EP97940149 A EP 97940149A EP 97940149 A EP97940149 A EP 97940149A EP 0858400 B1 EP0858400 B1 EP 0858400B1
Authority
EP
European Patent Office
Prior art keywords
structural elements
data carrier
areas
halftone image
area
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP97940149A
Other languages
German (de)
French (fr)
Other versions
EP0858400A1 (en
Inventor
Johann Müller
Stefan May
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Giesecke and Devrient GmbH
Original Assignee
Giesecke and Devrient GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Giesecke and Devrient GmbH filed Critical Giesecke and Devrient GmbH
Publication of EP0858400A1 publication Critical patent/EP0858400A1/en
Application granted granted Critical
Publication of EP0858400B1 publication Critical patent/EP0858400B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
    • B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
    • B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
    • B42D25/30—Identification or security features, e.g. for preventing forgery
    • B42D25/342—Moiré effects
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07D—HANDLING OF COINS OR VALUABLE PAPERS, e.g. TESTING, SORTING BY DENOMINATIONS, COUNTING, DISPENSING, CHANGING OR DEPOSITING
    • G07D7/00—Testing specially adapted to determine the identity or genuineness of valuable papers or for segregating those which are unacceptable, e.g. banknotes that are alien to a currency
    • G07D7/005—Testing security markings invisible to the naked eye, e.g. verifying thickened lines or unobtrusive markings or alterations
    • G07D7/0054—Testing security markings invisible to the naked eye, e.g. verifying thickened lines or unobtrusive markings or alterations involving markings the properties of which are altered from original properties
    • G07D7/0057—Testing security markings invisible to the naked eye, e.g. verifying thickened lines or unobtrusive markings or alterations involving markings the properties of which are altered from original properties involving markings which are altered in dimension, e.g. thickened lines

Definitions

  • the present invention relates to a data carrier, in particular a value document, with at least one halftone image represented by structural elements, where each structural element has a basic geometry and a size has, the size of the structural element a gray level of the halftone image represents and a process for its production.
  • the invention also relates to a data carrier, in particular a value document at least one picture element represented by several structural elements.
  • EP 0 710 574 A2 relates to a security document with a drawing, being on a copy of the security document a moiré pattern is created in the corresponding drawing.
  • a whole-surface raster structure with parallel lines is arranged.
  • the drawing is made in the form of a halftone image, in addition, as described in EP 0 085 066 B1, the line thicknesses of the lines can be varied in a contact grid structure. Furthermore, the distance the lines over the entire halftone image according to a modulation function varied. That varied over the entire area of the drawing the number of lines per unit length.
  • the present invention is therefore based on the object of a document with a structure creating a moiré pattern, in particular on a Halftone, to provide, with a copy of the Document large-area moiré structures for the detection of counterfeits are generated, with the structure generating the moiré pattern at the same time is inserted homogeneously in the halftone image and opposite as a background structure withdraws from the halftone image itself.
  • the invention is based on the idea of the total area of an image in which are to be created during a copying process, in to divide several areas. Each area will then have a number of Assigned structural elements with the help of those available in this area Grayscale should be created.
  • the number of structural elements is so in at least two adjacent areas chosen to be different in the two contiguous areas is. This different number inevitably results an offset of the structural elements relative to the structural element of the neighboring one Area.
  • the halftone image that is applied to the data carrier is divided into areas that have different raster frequencies exhibit.
  • When trying to copy this halftone image or with a Reading scanners into a data processing system overlays the Sampling frequency of the scanner or copier with the different applied Halftone halftone frequencies. This overlay leads however, disturbances in the reproduction of the halftone image, whereby this Interference in particular in the generation of a large-area moiré pattern noticeable.
  • the image has predetermined areas has, in each of which a predetermined number of structural elements is arranged, the number of structural elements per surface of an area different between at least two adjacent areas and the structural elements optionally in at least two the areas are staggered.
  • This has the advantage that even with different scanning grids, for example a copier or scanners, interference, such as moiré patterns, arise without that inhomogeneities of the total area grid, in particular of the halftone image, arise.
  • the structural elements have a Area of the halftone image on a uniform basic geometry, wherein the structural elements of all areas are particularly preferred to be uniform Have basic geometry.
  • the structural elements are preferred as lines executed, for each area separately a predetermined thickness represents a predetermined shade of gray on a line. So it is possible despite the division of the grayscale image into several areas with different Number of structural elements a homogeneous degree of brightness to ensure the entire grayscale image. Because lie, for example in a first area n structural elements in front and in the adjacent one Area n +10 structural elements, so it would, simply by the increase the number of structural elements, the second area optically darker represent as the first area. This difficulty is now avoided that within a range a predetermined width of the line predetermined gray tone while within a second Area that has, for example, a higher number of lines, one different, in this case smaller width of the line for the same given one Shade of gray is provided.
  • the halftone image has different screen frequencies has, which when scanning with the aid of a scanner or copier with the Sampling frequency of the device are superimposed by the variation the number of structural elements generated per area different Raster frequencies provide the ability to use multiple sampling frequencies Overlaying raster frequencies so that the probability for the Emergence of a moiré pattern can be significantly increased. simultaneously becomes the one associated with the increase in the number of structural elements Effect of darkening the individual areas avoided that the predetermined size of the structural elements a predetermined shade of gray within a range, however, corresponds to the predetermined sizes of the structural elements in the different areas depending on the Number of structure elements in each area different shades of gray can represent.
  • Fig. 1 shows an enlarged detail view of a portrait, which according to of the present invention as a halftone image with a moiré pattern Structure is shown.
  • the halftone image 10 is in different column-like Strips 14, 16, 22 divided, each containing a number of structural elements 12 have. In the present embodiment, this is 23 stripes, this number can also be chosen higher or lower.
  • Each Strip 14, 16, 22 is a number of line-shaped structural elements 12 assigned, which form a grid structure in each column.
  • the halftone 10 is shown from the linear structural elements 12, in each Range a certain line thickness to a certain shade of gray Halftone image 10 corresponds.
  • the horizontal linear structure elements 12 in their raster width and / or their Angular position vary.
  • Each strip 14, 16, 22 each contains a predetermined number of structural elements 12, i.e. a predetermined number of lines based on the total portrait height.
  • the line density is, for example, 20 lines per cm in the first strip 16.
  • the first strip 16 includes in the illustrated Embodiment 118 lines. This number of lines increases from stripes to Strip so that the last strip 22 with 171 lines in the preferred shown Embodiment is present.
  • a different number of lines means a different raster frequency for each stripe.
  • the raster frequency increases corresponding to the increase in the number of structural elements 12 in each Stripes from right to left too. This results in each of the 23 stripes a slightly different raster frequency, with at least one Screen frequency or at least a predetermined number of screen frequencies when scanning or copying through the overlay with the Sampling frequency of the scanner or copier a clearly visible, emerging Moire pattern generated.
  • straight lines are used as structural elements, which expanded symmetrically to represent a certain halftone be so that in each area a certain thickness of the line can be assigned to a predetermined shade of gray.
  • the lines are in Angles formed perpendicular to the division of the areas and can Ekken and highlight edges of the halftone image in particular if the areas are selected so that abutting areas along such a corner or edge.
  • the areas are the same width and almost have the same area
  • the halftone image can also be divided into areas different shape or width and different area.
  • the distances of the structural elements within one Ranges are constant, as shown in FIG. 1.
  • the columns 14, 16, 22 are around a predetermined one Spaced apart. This blends in with the moiré pattern generating structure more homogeneous, because a direct contact of the Moire pattern-producing structure of adjacent strips 14, 16, 22 abrupt transition jumps leads, which stand out visually strong. Thereby the optical appearance of the halftone image 10 is strongly negatively affected.
  • FIG. 2a to 2d illustrate attempts to copy the halftone image of Fig. 1 with different settings of the copier.
  • Fig. 2a to 2d immediately results at different scanning angles when copying at different locations of the halftone image 10 to different Moire patterns, however, occur in any copy attempt Form a moiré pattern at least in partial areas of the halftone image 10 clearly.
  • FIG. 3 shows an enlarged representation of a halftone image with a Moire pattern generating structure according to a second embodiment of the present invention.
  • This embodiment corresponds to the first one in FIG Fig. 1 illustrated embodiment, with the difference that the structural elements 12 in the areas 14 not as in the first embodiment 1, are arranged perpendicular to the subdivision of the areas 14, but are slightly tilted relative to the vertical of the column division.
  • FIGS. 4a and 4b illustrate two attempts to copy the halftone image of FIG. 3.
  • the 4a and 4b differ in that they have a different scanning angle when copying the halftone image of Fig. 3. It is immediate can be seen that with different scanning grids during the copying process in different areas 14 different moiré patterns are created. Even without a direct comparison with the halftone image of FIG. 3, and visible to the naked eye that it is not in Figs. 4a and 4b Original pictures, but copies.
  • moiré pattern generating Halftone image 10 consists of the tilt angle of the structural elements 12 additionally vary within the halftone image 10. This is prevents moiré pattern generation during the copying process appropriate selection of the scanning angle when copying is reduced or, if necessary is prevented.
  • this Copier does not have to have any special facilities to protect the copy to realize the present invention.
  • it is impossible to design a copying process so that with adjustment of the Scanning grid of the copier to the structure creating the moiré pattern Formation of moiré structures on copies can be prevented.
  • the Moire pattern generating structure according to the present invention responds to any type of copying process in that clearly prominent, visible and recognizable to the naked eye Moiré patterns arise on the copy, which can be identified immediately as a copy do.
  • FIG. 5 shows an enlarged illustration of two structural elements 18 analogous to the structural elements 12 of FIG. 1, but according to a third advantageous embodiment are particularly designed.
  • the Structural elements 18 themselves have grid lines 20 which form a grid structure within generate the structural element 18.
  • This grid structure itself can also have a color modulation for generating an image motif.
  • the Tonal value which is formed by the raster lines 20, can in particular Realize very well in the steel printing process because the depth of the steel pressure is a Is a measure of the color saturation and thus there is the possibility of using the Grid lines 20 adjust the tonal value of the structural element 18.
  • areas 14 as any Surfaces, preferably also without a predetermined geometric shape, such as square, rectangle, triangle or the like.
  • At least two adjacent, arbitrarily shaped surface areas differ according to the invention in the number of structural elements, such as lines, in a respective area and / or by the orientation of the structural elements in a surface area and / or by the shape of the structural elements in the respective area, such as lines in the form of straight lines, waves, guilloches or similar.
  • This new technology enables scanning or copying attempts to prevent or the scanned or copied objects clearly recognizable as a reproduction.
  • the inner areas of a can also be used as area areas Guilloche pattern can be used. Then within these areas by varying the angles, varying the lines per area and / or by variation of the line type the creation of a moiré pattern when copying generated or ensured.

Abstract

A data carrier with at least one halftone images 10 represented by structural elements 12, whereby a predetermined symmetrical widening of structural elements 12 represents a corresponding gray level of halftone image 10. Image 10 has predetermined areas 14, 16 and 22 each having a predetermined number or screen frequency of structural elements 12, the screen frequency of structural elements 12 per unit area of area 14, 16 and 22 being different between at least two areas 14, 16 and 22 and/or structural elements 12 being offset from each other in at least two areas 14, 16 and 22. A data carrier with such a halftone image 10 acquires a moiré pattern in at least predetermined areas of halftone image 10 when copied, so that a copy of the data carrier is recognizable immediately and with the naked eye (FIG. 1).

Description

Die vorliegende Erfindung betrifft einen Datenträger, insbesondere Wertdokument, mit wenigstens einem durch Strukturelemente dargestellten Halbtonbild, wobei jedes Strukturelement eine Grundgeometrie und eine Größe aufweist, wobei die Größe des Strukturelements eine Graustufe des Halbtonbildes repräsentiert sowie ein Verfahren zu dessen Herstellung. Die Erfindung betrifft ferner einen Datenträger, insbesondere Wertdokument, mit wenigstens einem durch mehrere Strukturelemente dargestellten Bildelement.The present invention relates to a data carrier, in particular a value document, with at least one halftone image represented by structural elements, where each structural element has a basic geometry and a size has, the size of the structural element a gray level of the halftone image represents and a process for its production. The invention also relates to a data carrier, in particular a value document at least one picture element represented by several structural elements.

Ein besonderes Problem bei Dokumenten, wie beispielsweise Wertdokumenten, stellt der Schutz vor Fälschungen, insbesondere durch Kopieren bzw. Abscannen eines echten Dokuments zur Herstellung eines gefälschten Dokuments, dar. So betrifft beispielsweise die EP 0 710 574 A2 ein Sicherheitsdokument mit einer Zeichnung, wobei auf einer Kopie des Sicherheitsdokuments in der entsprechenden Zeichnung ein Moirémuster entsteht. Hierzu ist vorgesehen, daß eine ganzflächige Rasterstruktur mit parallelen Linien angeordnet ist. Die Zeichnung wird in Form eines Halbtonbildes gebildet, wobei dazu, wie in der EP 0 085 066 B1 beschrieben, die Strichdicken der Linien in einer Kontaktrasterstruktur variiert werden. Ferner wird der Abstand der Linien über das gesamte Halbtonbild entsprechend einer Modulationsfunktion variiert. D.h. über die gesamte Fläche der Zeichnung variiert die Anzahl der Linien pro Längeneinheit. Die Modifikation einer derartigen Liniendichte führt zu einem Kopierschutz gegen Farbkopierer oder Scanner, da die Überlagerung der Rasterstruktur wenigstens in einem vorbestimmten Bereich mit dem Abtastraster des Kopierer oder Scanners ein deutlich hervortretendes Moirémuster erzeugt. Da dieses Moirémuster nur auf der Kopie, jedoch nicht auf dem Original zu sehen ist, ist die Kopie als Fälschung einfach identifizierbar. A particular problem with documents, such as value documents, provides protection against counterfeiting, especially by copying or Scanning a real document to produce a fake document, For example, EP 0 710 574 A2 relates to a security document with a drawing, being on a copy of the security document a moiré pattern is created in the corresponding drawing. For this it is envisaged that a whole-surface raster structure with parallel lines is arranged. The drawing is made in the form of a halftone image, in addition, as described in EP 0 085 066 B1, the line thicknesses of the lines can be varied in a contact grid structure. Furthermore, the distance the lines over the entire halftone image according to a modulation function varied. That varied over the entire area of the drawing the number of lines per unit length. The modification of such Line density leads to copy protection against color copiers or scanners, since the overlay of the raster structure is at least in a predetermined one Area with the scanning grid of the copier or scanner a clearly protruding Moire pattern created. Since this moiré pattern is only on the copy, However, the copy cannot be seen on the original as a forgery easily identifiable.

In EP 0 204 552 A2 werden Dokumente zum Erschweren einer Fälschung mit einer Fläche versehen, die in einzelne Blöcke unterteilt wird. Die einzelnen Blöcke werden mit unterschiedlich orientierten Linien versehen, deren Breite und Abstand so variiert wird, dass die Gesamtfläche bei normalem Betrachtungsabstand insgesamt homogen und von gleichem Farbton erscheint. Die hier beschriebene Halbtonseparationstechnik eignet sich jedoch nicht zur Wiedergabe von Halbtonbildern. In EP 0 204 552 A2, documents for complicating a forgery are included an area that is divided into individual blocks. The single ones Blocks are provided with differently oriented lines, their width and distance is varied so that the total area at normal viewing distance appears overall homogeneous and of the same color. The However, the halftone separation technique described here is not suitable for Play halftone images.

Zwar gibt es durch die Änderung der Liniendichte selbst bei unterschiedlichen Rastern der Scanner-Abtastung wenigstens in vorbestimmten Bereichen einen Moiré-Effekt, jedoch wirkt sich die Variation der Liniendichte über die gesamte Fläche der Zeichnung äußerst negativ auf das optische Aussehen des Halbtonbildes aus. Durch den Wechsel hoher und niedriger Dichte bzw. Anzahl von Linien pro Flächeneinheit wirkt das Bild unruhig, inhomogen und das Rastermuster dominiert das Halbtonbild statt umgekehrt, so daß das Bild ästhetisch wenig ansprechend ist.By changing the line density there are even different ones Rasterize the scanner scan at least in predetermined areas a moiré effect, but the variation in line density affects the entire area of the drawing extremely negative on the visual appearance of the halftone. By alternating high and low density or The number of lines per unit area makes the image appear restless, inhomogeneous and the halftone pattern dominates the halftone image instead of vice versa, so that the picture is aesthetically unappealing.

Der vorliegenden Erfindung liegt daher die Aufgabe zugrunde, ein Dokument mit einer Moirémuster erzeugenden Struktur, insbesondere auf einem Halbtonbild, zur Verfügung zu stellen, wobei bei einem Kopiervorgang des Dokuments großflächige Moiréstrukturen zur Erkennung von Fälschungen erzeugt werden, wobei gleichzeitig die Moirémuster erzeugende Struktur homogen in das Halbtonbild eingefügt ist und als Hintergrundstruktur gegenüber dem Halbtonbild selbst zurücktritt.The present invention is therefore based on the object of a document with a structure creating a moiré pattern, in particular on a Halftone, to provide, with a copy of the Document large-area moiré structures for the detection of counterfeits are generated, with the structure generating the moiré pattern at the same time is inserted homogeneously in the halftone image and opposite as a background structure withdraws from the halftone image itself.

Diese Aufgabe wird bei einem Dokument der obengenannten Art durch die kennzeichnenden Merkmale der unabhängigen Ansprüche gelöst.This task is performed by a document of the type mentioned above characteristic features of the independent claims solved.

Der Erfindung liegt der Gedanke zugrunde, die Gesamtfläche eines Bildes, in dem bei einem Kopiervorgang Moiréstrukturen erzeugt werden sollen, in mehrere Bereiche aufzuteilen. Jedem Bereich wird dann eine Anzahl von Strukturelementen zugeordnet, mit deren Hilfe die in diesem Bereich vorhandenen Graustufen erzeugt werden sollen. Die Anzahl der Strukturelemente wird in wenigstens zwei aneinandergrenzenden Bereichen dabei so gewählt, dass sie in den beiden aneinandergrenzenden Bereichen unterschiedlich ist. Durch diese unterschiedliche Anzahl ergibt sich zwangsläufig ein Versatz der Strukturelemente relativ zum Strukturelement des benachbarten Bereiches. Somit wird das Halbtonbild, das auf den Datenträger aufgebracht wird, in Bereiche aufgeteilt, die unterschiedliche Rasterfrequenzen aufweisen. Beim Versuch, dieses Halbtonbild zu kopieren bzw. mit einem Scanner in eine Datenverarbeitungsanlage einzulesen, überlagert sich die Abtastfrequenz des Scanners oder Kopierers mit den aufgebrachten, unterschiedlichen Rasterfrequenzen des Halbtonbildes. Diese Überlagerung führt jedoch zu Störungen in der Reproduktion des Halbtonbildes, wobei sich diese Störung insbesondere in der Erzeugung eines großflächigen Moirémusters bemerkbar macht.The invention is based on the idea of the total area of an image in which are to be created during a copying process, in to divide several areas. Each area will then have a number of Assigned structural elements with the help of those available in this area Grayscale should be created. The number of structural elements is so in at least two adjacent areas chosen to be different in the two contiguous areas is. This different number inevitably results an offset of the structural elements relative to the structural element of the neighboring one Area. Thus the halftone image that is applied to the data carrier is divided into areas that have different raster frequencies exhibit. When trying to copy this halftone image or with a Reading scanners into a data processing system overlays the Sampling frequency of the scanner or copier with the different applied Halftone halftone frequencies. This overlay leads however, disturbances in the reproduction of the halftone image, whereby this Interference in particular in the generation of a large-area moiré pattern noticeable.

Durch die Variation der Anzahl der Strukturelemente in den Bereichen des Halbtonbildes wird für jeden Bereich eine andere Rasterfrequenz erzeugt, so daß sichergestellt ist, daß selbst bei Verändern des Abtastrasters, also der Scann- oder Kopierfrequenz, ein Moirémuster entsteht. Dies erscheint dann jeweils in den Bereichen der Gesamtfläche, für die Abtast- und Rasterfrequenz so aufeinander abgestimmt sind, daß ein Moirémuster entstehen kann.By varying the number of structural elements in the areas of Halftone image a different raster frequency is generated for each area, so that it is ensured that even when the scanning grid, ie the Scanning or copying frequency, a moiré pattern is created. This then appears in each case in the areas of the total area, for the sampling and raster frequency are coordinated so that a moiré pattern is created can.

Erfindungsgemäß ist somit vorgesehen, daß das Bild vorbestimmte Bereiche aufweist, in denen jeweils eine vorbestimmte Anzahl von Strukturelementen angeordnet ist, wobei die Anzahl der Strukturelemente pro Fläche eines Bereichs zwischen mindestens zwei aneinandergrenzenden Bereichen unterschiedlich ist und die Strukturelemente gegebenenfalls in mindestens zwei der Bereiche gegeneinander versetzt angeordnet sind. Dies hat den Vorteil, daß auch bei unterschiedlichen Abtastrastern, beispielsweise eines Kopierers oder Scanners, Störungen, wie beispielsweise Moirémuster, entstehen ohne daß Inhomogenitäten des Gesamtflächenrasters, insbesondere des Halbtonbildes, entstehen. It is thus provided according to the invention that the image has predetermined areas has, in each of which a predetermined number of structural elements is arranged, the number of structural elements per surface of an area different between at least two adjacent areas and the structural elements optionally in at least two the areas are staggered. This has the advantage that even with different scanning grids, for example a copier or scanners, interference, such as moiré patterns, arise without that inhomogeneities of the total area grid, in particular of the halftone image, arise.

In einer bevorzugten Ausführungsform weisen die Strukturelemente eines Bereiches des Halbtonbildes eine einheitliche Grundgeometrie auf, wobei besonders bevorzugt die Strukturelemente aller Bereiche eine einheitliche Grundgeometrie haben. Die Strukturelemente sind bevorzugt als Linien ausgeführt, wobei für jeden Bereich separat eine jeweils vorbestimmte Dicke einer Linie einen vorbestimmten Grauton repräsentiert. Damit ist es möglich, trotz der Aufteilung des Graustufenbildes in mehrere Bereiche mit unterschiedlicher Anzahl von Strukturelementen einen homogen Helligkeitsgrad über das gesamte Graustufenbild zu gewährleisten. Denn liegen beispielsweise in einem ersten Bereich n Strukturelemente vor und in dem benachbarten Bereich n +10 Strukturelemente, so würde sich, alleine durch die Zunahme der Anzahl der Strukturelemente, der zweite Bereich optisch dunkler darstellen als der erste Bereich. Diese Schwierigkeit wird nun dadurch umgangen, daß innerhalb eines Bereiches eine vorgegebene Breite der Linie einem vorgegebenen Grauton entspricht, während innerhalb eines zweiten Bereiches, der beispielsweise eine höhere Anzahl von Linien aufweist, eine andere, in diesem Fall geringere Breite der Linie für den gleichen vorgegebenen Grauton vorgesehen wird.In a preferred embodiment, the structural elements have a Area of the halftone image on a uniform basic geometry, wherein the structural elements of all areas are particularly preferred to be uniform Have basic geometry. The structural elements are preferred as lines executed, for each area separately a predetermined thickness represents a predetermined shade of gray on a line. So it is possible despite the division of the grayscale image into several areas with different Number of structural elements a homogeneous degree of brightness to ensure the entire grayscale image. Because lie, for example in a first area n structural elements in front and in the adjacent one Area n +10 structural elements, so it would, simply by the increase the number of structural elements, the second area optically darker represent as the first area. This difficulty is now avoided that within a range a predetermined width of the line predetermined gray tone while within a second Area that has, for example, a higher number of lines, one different, in this case smaller width of the line for the same given one Shade of gray is provided.

Mit der erfindungsgemäßen Darstellung der Halbtonbilder durch Bereiche mit einer unterschiedlichen Anzahl von Strukturelementen kann somit der Vorteil erzielt werden, daß das Halbtonbild verschiedene Rasterfrequenzen aufweist, die beim Abtasten mit Hilfe eines Scanners oder Kopierers mit der Abtastfrequenz des Gerätes überlagert werden und die durch die Variation der Anzahl der Strukturelemente je Bereich erzeugten unterschiedlichen Rasterfrequenzen die Möglichkeit liefern, die Abtastfrequenzen mit mehreren Rasterfrequenzen zu überlagern, so daß die Wahrscheinlichkeit für die Entstehung eines Moirémusters deutlich erhöht werden kann. Gleichzeitig wird der mit der Erhöhung der Anzahl der Strukturelemente einhergehende Effekt der Verdunkelung der einzelnen Bereiche dadurch vermieden, daß die vorbestimmte Größe der Strukturelemente einem vorbestimmten Grauton innerhalb eines Bereiches entspricht, daß jedoch die vorbestimmten Größen der Strukturelemente in den unterschiedlichen Bereichen abhängig von der Anzahl der Strukturelemente in jedem Bereich unterschiedliche Grautöne repräsentieren können.With the representation of the halftone images by areas according to the invention with a different number of structural elements, the Advantage can be achieved that the halftone image has different screen frequencies has, which when scanning with the aid of a scanner or copier with the Sampling frequency of the device are superimposed by the variation the number of structural elements generated per area different Raster frequencies provide the ability to use multiple sampling frequencies Overlaying raster frequencies so that the probability for the Emergence of a moiré pattern can be significantly increased. simultaneously becomes the one associated with the increase in the number of structural elements Effect of darkening the individual areas avoided that the predetermined size of the structural elements a predetermined shade of gray within a range, however, corresponds to the predetermined sizes of the structural elements in the different areas depending on the Number of structure elements in each area different shades of gray can represent.

Weitere Merkmale, Vorteile und bevorzugte Ausführungen der vorliegenden Erfindung ergeben sich aus den Unteransprüchen und der nachfolgenden Beschreibung der Figuren. Dabei zeigen:

Fig. 1
in einer vergrößerten Darstellung ein Halbtonbild mit Moirémuster erzeugender Struktur gemäß einer ersten Ausführungsform der vorliegenden Erfindung,
Fig. 2a - 2d
mehrere Kopierversuche des erfindungsgemäßen Halbtonbildes von Fig. 1,
Fig. 3
in einer vergrößerten Darstellung ein Halbtonbild mit Moirémuster erzeugender Struktur gemäß einer zweiten Ausführungsform der vorliegenden Erfindung,
Fig. 4a - 4b
zwei Kopierversuche des erfindungsgemäßen Halbtonbilds von Fig. 3 und
Fig. 5
in vergrößerter Darstellung zwei Strukturelemente, die gemäß einer dritten vorteilhaften Ausführungsform der vorliegenden Erfindung dargestellt sind.
Further features, advantages and preferred embodiments of the present invention result from the subclaims and the following description of the figures. Show:
Fig. 1
FIG. 2 shows an enlarged representation of a halftone image with a structure generating a moiré pattern according to a first embodiment of the present invention, FIG.
2a-2d
several attempts to copy the halftone image according to the invention from FIG. 1,
Fig. 3
FIG. 2 shows an enlarged representation of a halftone image with a structure generating a moiré pattern according to a second embodiment of the present invention, FIG.
4a-4b
two attempts to copy the halftone image of FIGS. 3 and
Fig. 5
in an enlarged view two structural elements, which are shown according to a third advantageous embodiment of the present invention.

Fig. 1 zeigt eine vergrößerte Detaildarstellung eines Portraits, welches gemäß der vorliegenden Erfindung als Halbtonbild mit Moirémuster erzeugender Struktur dargestellt ist. Das Halbtonbild 10 ist in verschiedene spaltenartige Streifen 14, 16, 22 aufgeteilt, die jeweils eine Anzahl von Strukturelementen 12 aufweisen. In der vorliegenden Ausführungsform sind dies 23 Streifen, wobei diese Zahl auch höher oder niedriger gewählt werden kann. Jedem Streifen 14,16, 22 ist eine Anzahl von linienförmigen Strukturelementen 12 zugeordnet, die in jeder Spalte eine Rasterstruktur bilden. Das Halbtonbild 10 ist aus den linienförmigen Strukturelementen 12 dargestellt, wobei in jedem Bereich eine bestimmte Liniendicke einem bestimmten Grautonwert des Halbtonbildes 10 entspricht.Fig. 1 shows an enlarged detail view of a portrait, which according to of the present invention as a halftone image with a moiré pattern Structure is shown. The halftone image 10 is in different column-like Strips 14, 16, 22 divided, each containing a number of structural elements 12 have. In the present embodiment, this is 23 stripes, this number can also be chosen higher or lower. Each Strip 14, 16, 22 is a number of line-shaped structural elements 12 assigned, which form a grid structure in each column. The halftone 10 is shown from the linear structural elements 12, in each Range a certain line thickness to a certain shade of gray Halftone image 10 corresponds.

Innerhalb einer Spalte bzw. eines Streifens 14, 16, 22 können die waagerechten linienförmigen Strukturelemente 12 in ihrer Rasterweite und/oder ihrer Winkellage variieren.Within a column or a strip 14, 16, 22, the horizontal linear structure elements 12 in their raster width and / or their Angular position vary.

Jeder Streifen 14,16, 22 enthält jeweils eine vorbestimmt Anzahl von Strukturelementen 12, d.h. eine vorbestimmte Linienzahl bezogen auf die Gesamtportraithöhe. Die Liniendichte beträgt beispielsweise 20 Linien pro cm im ersten Streifen 16. Der erste Streifen 16 beinhaltet in der dargestellten Ausführungsform 118 Linien. Diese Linienzahl erhöht sich von Streifen zu Streifen, so daß der letzte Streifen 22 mit 171 Linien in der dargestellten bevorzugten Ausführungsform vorliegt.Each strip 14, 16, 22 each contains a predetermined number of structural elements 12, i.e. a predetermined number of lines based on the total portrait height. The line density is, for example, 20 lines per cm in the first strip 16. The first strip 16 includes in the illustrated Embodiment 118 lines. This number of lines increases from stripes to Strip so that the last strip 22 with 171 lines in the preferred shown Embodiment is present.

Da alle Streifen des in Fig. 1 dargestellten Portraits die gleiche Höhe aufweisen, bedeutet eine unterschiedliche Linienzahl eine unterschiedliche Rasterfrequenz für jeden Streifen. Wie in Fig. 1 gezeigt, nimmt die Rasterfrequenz entsprechend der Zunahme der Anzahl der Strukturelemente 12 in jedem Streifen von rechts nach links zu. Hierdurch ergibt sich in jedem der 23 Streifen eine etwas unterschiedliche Rasterfrequenz, wobei wenigstens eine Rasterfrequenz oder wenigstens eine vorbestimmte Anzahl von Rasterfrequenzen beim Abscannen oder Kopieren durch die Überlagerung mit der Abtastfrequenz des Scanners oder Kopierers ein deutlich sichtbares, hervortretendes Moiremuster erzeugt.Since all strips of the portrait shown in FIG. 1 have the same height, a different number of lines means a different raster frequency for each stripe. As shown in Fig. 1, the raster frequency increases corresponding to the increase in the number of structural elements 12 in each Stripes from right to left too. This results in each of the 23 stripes a slightly different raster frequency, with at least one Screen frequency or at least a predetermined number of screen frequencies when scanning or copying through the overlay with the Sampling frequency of the scanner or copier a clearly visible, emerging Moire pattern generated.

Dies erzielt einen wirksamen Kopierschutz eines Dokuments, das mit einem Bild 10 gemäß Fig. 1 versehen ist, wobei die Variation der Zahl der Strukturelemente 12 in den verschiedenen Bereichen 14,16 und 22 das Halbtonbild nicht negativ beeinflußt bzw. zusätzlich, beispielsweise zur Hervorhebung von Kanten oder Ecken, verwendet werden kann.This achieves an effective copy protection of a document that has a Figure 10 is provided according to FIG. 1, the variation in the number of structural elements 12 in the different areas 14, 16 and 22 the halftone image not negatively influenced or additionally, for example for highlighting edges or corners.

Im Beispiel gemäß Fig. 1 werden als Strukturelemente gerade Linien verwendet, die zur Darstellung eines bestimmten Halbtones symmetrisch aufgeweitet werden, so daß in jedem Bereich eine bestimmte Dicke der Linie einem vorbestimmten Grauton zugeordnet werden kann. Die Linien sind im Winkel senkrecht zur Aufteilung der Bereiche ausgebildet und können Ekken und Kanten des Halbtonbildes insbesondere dann hervorheben, wenn die Bereiche so ausgewählt werden, daß aneinanderstoßende Bereiche entlang einer solchen Ecke oder Kante verlaufen.In the example according to FIG. 1, straight lines are used as structural elements, which expanded symmetrically to represent a certain halftone be so that in each area a certain thickness of the line can be assigned to a predetermined shade of gray. The lines are in Angles formed perpendicular to the division of the areas and can Ekken and highlight edges of the halftone image in particular if the areas are selected so that abutting areas along such a corner or edge.

Neben der Darstellung der Strukturelemente durch Linien ist es auch möglich, andere geometrische Grundformen als Strukturelemente, wie beispielsweise Kurven, Punkte, Kreise oder ähnliches, zu verwenden.In addition to the representation of the structural elements by lines, it is also possible basic geometric shapes other than structural elements, such as To use curves, points, circles or the like.

Obwohl, wie in Fig. 1 dargestellt, die Bereiche gleiche Breite und nahezu gleiche Fläche haben, kann die Aufteilung des Halbtonbildes auch in Bereicher unterschiedlicher Form oder Breite sowie unterschiedlicher Fläche erfolgen. Darüber hinaus ist auch möglich, die Grundgeometrie und/oder die Orientierung der Strukturelemente innerhalb zweier, vorzugsweise aneinandergrenzender Bereiche zu variieren. Dadurch wird eine noch breitere Abdeckung der unterschiedlichen Abtastfrequenzen der eingesetzten Scanner oder Kopierer erzielt. Die Abstände der Strukturelemente innerhalb eines Bereiches sind, wie in Fig. 1 gezeigt, konstant. Ferner stellen mehrere unterschiedliche Anordnungen der Strukturelemente sicher, daß selbst bei zufälligem Aufeinandertreffen der Abtastfrequenz eines Scanners oder beispielsweise eines Farbkopierers und einer Rasterstruktur eines bestimmten Streifens 14, bei dem kein Moirémuster erzeugt wird, dennoch bei wenigstens einer anderen Rasterstruktur eines anderen Bereiches 16, 22 beim Kopieren ein Moirémuster entsteht. Damit entsteht bei der Reproduktion zumindest auf Teilbereichen der Reproduktion auch dann ein Moirémuster, wenn das Dokument unter verschiedenen Winkeln gescannt wird.Although, as shown in Fig. 1, the areas are the same width and almost have the same area, the halftone image can also be divided into areas different shape or width and different area. In addition, it is also possible to use the basic geometry and / or the Orientation of the structural elements within two, preferably adjacent To vary ranges. This will make it even wider Coverage of the different scanning frequencies of the scanners used or copier. The distances of the structural elements within one Ranges are constant, as shown in FIG. 1. Furthermore, several different arrangements of the structural elements ensure that even at accidental collision of the scanning frequency of a scanner or for example a color copier and a raster structure of a particular one Strip 14, in which no moiré pattern is produced, but at least another raster structure of another area 16, 22 when copying a moiré pattern is created. At least this creates during reproduction a moiré pattern on parts of the reproduction, when the document is scanned at different angles.

In besonders vorteilhafter Weise sind die Spalten 14,16, 22 um eine vorbestimmte Weite voneinander beabstandet. Dadurch fügt sich die Moirémuster erzeugende Struktur homogener ein, da eine direkte Berührung der Moirémuster erzeugenden Struktur von benachbarten Streifen 14, 16, 22 zu abrupten Übergangssprüngen führt, die optisch stark hervortreten. Dadurch wird das optische Erscheinungsbild des Halbtonbildes 10 stark negativ beeinflußt.In a particularly advantageous manner, the columns 14, 16, 22 are around a predetermined one Spaced apart. This blends in with the moiré pattern generating structure more homogeneous, because a direct contact of the Moire pattern-producing structure of adjacent strips 14, 16, 22 abrupt transition jumps leads, which stand out visually strong. Thereby the optical appearance of the halftone image 10 is strongly negatively affected.

Die Fig. 2a bis 2d veranschaulichen Kopierversuche des Halbtonbildes von Fig. 1 mit verschiedenen Einstellungen des Kopierers. Wie sich aus den Fig. 2a bis 2d unmittelbar ergibt, kommt es bei verschiedenen Abtastwinkeln beim Kopieren an unterschiedlichen Stellen des Halbtonbildes 10 zu verschiedenen Moirémustern, jedoch tritt bei jedem Kopierversuch in irgendeiner Form ein Moirémuster zumindest in Teilbereichen des Halbtonbildes 10 deutlich hervor. Dies macht in einer Kopie des Bildes von Fig. 1 gegenüber dem Original von Fig. 1 sofort und deutlich erkennbar, daß eine Fälschung durch Kopieren bzw. Abscannen erfolgt ist.2a to 2d illustrate attempts to copy the halftone image of Fig. 1 with different settings of the copier. As can be seen from the Fig. 2a to 2d immediately results at different scanning angles when copying at different locations of the halftone image 10 to different Moire patterns, however, occur in any copy attempt Form a moiré pattern at least in partial areas of the halftone image 10 clearly. This contrasts with a copy of the image of FIG. 1 the original of Fig. 1 immediately and clearly recognizable that a forgery by copying or scanning.

Fig. 3 zeigt in einer vergrößerten Darstellung ein Halbtonbild mit einer Moirémuster erzeugenden Struktur gemäß einer zweiten Ausführungsform der vorliegenden Erfindung. Diese Ausführungsform entspricht der ersten in Fig. 1 dargestellten Ausführungsform, mit dem Unterschied, daß die Strukturelemente 12 in den Bereichen 14 nicht, wie in der ersten Ausführungsform von Fig. 1, senkrecht zur Unterteilung der Bereiche 14 angeordnet sind, sondern gegenüber der Senkrechten der Spaltenaufteilung leicht verkippt sind.Fig. 3 shows an enlarged representation of a halftone image with a Moire pattern generating structure according to a second embodiment of the present invention. This embodiment corresponds to the first one in FIG Fig. 1 illustrated embodiment, with the difference that the structural elements 12 in the areas 14 not as in the first embodiment 1, are arranged perpendicular to the subdivision of the areas 14, but are slightly tilted relative to the vertical of the column division.

Fig. 4a und 4b stellen zwei Kopierversuche des Halbtonbildes von Fig. 3 dar. Wie sich aus den Fig. 4a und 4b deutlich ergibt, kommt es durch den Abtastvorgang beim Kopieren zu deutlich hervortretenden Moirémustern. Die Fig. 4a und 4b unterscheiden sich dabei durch einen unterschiedlichen Abtastwinkel beim Kopieren des Halbtonbildes von Fig. 3. Es ist unmittelbar ersichtlich, daß bei unterschiedlichen Abtastrastern beim Kopiervorgang in unterschiedlichen Bereichen 14 unterschiedliche Moirémuster entstehen. Selbst ohne direkten Vergleich mit dem Halbtonbild von Fig. 3 ist sofort und mit bloßem Auge erkennbar, daß es sich bei den Fig. 4a und 4b nicht um Originalbilder, sondern um Kopien handelt.4a and 4b illustrate two attempts to copy the halftone image of FIG. 3. As can be clearly seen from FIGS. 4a and 4b, it comes through the scanning process when copying to clearly protruding moiré patterns. The 4a and 4b differ in that they have a different scanning angle when copying the halftone image of Fig. 3. It is immediate can be seen that with different scanning grids during the copying process in different areas 14 different moiré patterns are created. Even without a direct comparison with the halftone image of FIG. 3, and visible to the naked eye that it is not in Figs. 4a and 4b Original pictures, but copies.

Eine weitere vorteilhafte Ausführungsform des Moirémuster erzeugenden Rasters in Halbtonbild 10 besteht darin, den Kippwinkel der Strukturelemente 12 zusätzlich innerhalb des Halbtonbildes 10 zu variieren. Dadurch ist verhindert, daß eine Moirémuster-Erzeugung beim Kopiervorgang durch entsprechende Wahl des Abtastwinkels beim Kopieren vermindert oder gegebenenfalls verhindert wird. In diesem Zusammenhang sei darauf hingewiesen, daß das Kopiergerät keine besonderen Einrichtungen haben muß, um den Kopierschutz der vorliegenden Erfindung zu realisieren. Ferner ist es ausgeschlossen, einen Kopiervorgang derart auszugestalten, daß unter Anpassung des Abtastrasters des Kopierers an die Moirémuster erzeugende Struktur die Bildung von Moiréstrukturen auf Kopien verhindert werden kann. Die Moirémuster erzeugende Struktur gemäß der vorliegenden Erfindung spricht auf jeden, wie auch immer gearteten Kopiervorgang dadurch an, daß deutlich hervortretende, mit bloßem Auge sichtbare und erkennbare Moirémuster auf der Kopie entstehen, die diese sofort als Kopie identifizierbar machen.Another advantageous embodiment of the moiré pattern generating Halftone image 10 consists of the tilt angle of the structural elements 12 additionally vary within the halftone image 10. This is prevents moiré pattern generation during the copying process appropriate selection of the scanning angle when copying is reduced or, if necessary is prevented. In this context, it should be noted that this Copier does not have to have any special facilities to protect the copy to realize the present invention. Furthermore, it is impossible to design a copying process so that with adjustment of the Scanning grid of the copier to the structure creating the moiré pattern Formation of moiré structures on copies can be prevented. The Moire pattern generating structure according to the present invention responds to any type of copying process in that clearly prominent, visible and recognizable to the naked eye Moiré patterns arise on the copy, which can be identified immediately as a copy do.

Fig. 5 zeigt in einer vergrößerten Darstellung zwei Strukturelemente 18 analog den Strukturelementen 12 von Fig. 1, die jedoch gemäß einer dritten vorteilhaften Ausführungsform besonders ausgeführt sind. Dabei weisen die Strukturelemente 18 selbst Rasterlinien 20 auf, die eine Rasterstruktur innerhalb des Strukturelementes 18 erzeugen. Diese Rasterstruktur selbst kann auch eine Farbmodulation zur Erzeugung eines Bildmotivs aufweisen. Der Tonwert, der durch die Rasterlinien 20 gebildet wird, läßt sich insbesondere sehr gut im Stahldruckverfahren realisieren, da die Tiefe des Stahldrucks ein Maß für die Farbsättigung ist und somit die Möglichkeit besteht, über die Rasterlinien 20 den Tonwert des Strukturelementes 18 einzustellen.5 shows an enlarged illustration of two structural elements 18 analogous to the structural elements 12 of FIG. 1, but according to a third advantageous embodiment are particularly designed. The Structural elements 18 themselves have grid lines 20 which form a grid structure within generate the structural element 18. This grid structure itself can also have a color modulation for generating an image motif. The Tonal value, which is formed by the raster lines 20, can in particular Realize very well in the steel printing process because the depth of the steel pressure is a Is a measure of the color saturation and thus there is the possibility of using the Grid lines 20 adjust the tonal value of the structural element 18.

Selbstverständlich ist eine Kombination der beiden Ausführungsformen von Fig. 1 und 3 mit der zweiten Ausführungsform von Fig. 5 derart möglich, daß ein Strukturelement 12 der Ausführungsform von Fig. 1 oder 3 gemäß einem Strukturelement 18 der Ausführungsform von Fig. 5 dargestellt wird.Of course, a combination of the two embodiments of FIG 1 and 3 possible with the second embodiment of FIG. 5, that a structural element 12 according to the embodiment of FIG. 1 or 3 a structural element 18 of the embodiment of FIG. 5 is shown.

Zwar ist es unter Umständen möglich, daß ein beim Kopieren entstehendes Moirémuster bei der dritten Ausführungsform gemäß Fig. 5 nicht mit bloßem Auge erkennbar ist, jedoch sind Abweichungen der durch die Rasterlinien 20 erzeugten Rasterstruktur vom Original gegenüber der Kopie mit der Lupe sichtbar, so daß Fälschungen eindeutig identifizierbar sind.Under certain circumstances it is possible that something that arises during copying Moire pattern in the third embodiment according to FIG. 5 not with mere Eye can be seen, however, are deviations caused by the grid lines 20 generated raster structure from the original versus the copy with the Magnifying glass visible so that counterfeits can be clearly identified.

Obwohl in den dargestellten Ausrührungsformen der Fig.1 und 3 die Unterteilung des Halbtonbildes 10 in Bereiche 14 in Längsspalten erfolgt, gehört es durchaus zum Umfang der vorliegenden Erfindung, die Bereiche 14 als beliebige Flächen, vorzugsweise auch ohne vorbestimmte geometrische Form, wie beispielsweise Quadrat, Rechteck, Dreieck oder ähnliches, auszubilden. Wenigsten zwei aneinandergrenzende, beliebig ausgeformte Flächenbereiche unterscheiden sich erfindungsgemäß durch die Zahl der Strukturelemente, wie beispielsweise Linien, in einem jeweiligen Flächenbereich und/oder durch die Orientierung der Strukturelemente in einem Flächenbereich und/oder durch die Form der Strukturelemente in dem jeweiligen Flächenbereich, wie beispielsweise Linien in Form von Geraden, Wellen, Guillochen oder ähnlichem. Diese neue Technik ermöglicht es, Scann- oder Kopierversuche zu verhindern bzw. die gescannten oder kopierten Objekte eindeutig als Reproduktion zu erkennen.Although in the illustrated embodiments of Figures 1 and 3, the subdivision of the halftone image 10 takes place in areas 14 in longitudinal columns, it belongs well within the scope of the present invention, areas 14 as any Surfaces, preferably also without a predetermined geometric shape, such as square, rectangle, triangle or the like. At least two adjacent, arbitrarily shaped surface areas differ according to the invention in the number of structural elements, such as lines, in a respective area and / or by the orientation of the structural elements in a surface area and / or by the shape of the structural elements in the respective area, such as lines in the form of straight lines, waves, guilloches or similar. This new technology enables scanning or copying attempts to prevent or the scanned or copied objects clearly recognizable as a reproduction.

Als Flächenbereiche können beispielsweise auch die inneren Flächen eines Guillochenmusters verwendet werden. Innerhalb dieser Flächen wird dann durch Variation der Winkel, Variation der Linien pro Fläche und/oder durch Variation der Linienart die Entstehung eines Moirémusters beim Kopieren erzeugt bzw. sichergestellt.For example, the inner areas of a can also be used as area areas Guilloche pattern can be used. Then within these areas by varying the angles, varying the lines per area and / or by variation of the line type the creation of a moiré pattern when copying generated or ensured.

Claims (22)

  1. A data carrier, in particular document of value, with at least one halftone image (10) represented by structural elements (12, 18), each structural element having a basic geometry and a size whereby the size of the structural element (12, 18) represents a gray level of the halftone image (10), characterized in that the halftone image (10) has at least two contiguous areas (14, 16, 22) each having a predetermined number of structural elements (12, 18), the number of structural elements (12, 18) per unit area being different in at least two contiguous areas (14, 16, 22) and the structural elements (12, 18) within an area (14, 16, 22) having a distance which is constant.
  2. The data carrier of claim 1, characterized in that the structural elements (12, 18) in at least two contiguous areas (14, 16, 22) are offset from each other.
  3. The data carrier of claim 1 or 2, characterized in that all structural elements (12, 18) of one or more areas (14, 16, 22) have a uniform basic geometry.
  4. The data carrier of claim 3, characterized in that the predetermined size of the structural elements consists in a predetermined symmetrical widening of their basic geometry.
  5. The data carrier of any of claims 1 to 4, characterized in that the structural elements (12, 18) are lines.
  6. The data carrier of claim 5, characterized in that all lines (12, 18) forming the halftone image (10) are aligned essentially in the same direction at least within one area (14, 16, 22).
  7. The data carrier of at least one of claims 5 to 6, characterized in that the lines (12, 18) are aligned essentially perpendicular to the division of the areas (14, 16, 22).
  8. The data carrier of at least one of claims 1 to 7, characterized in that the predetermined size of a structural element (12, 18) corresponds to a predetermined gray level within an area (14, 16, 22).
  9. The data carrier of at least one of claims 1 to 8, characterized in that the halftone image (10) is printed on the data carrier.
  10. The data carrier of at least one of claims 1 to 9, characterized in that the data carrier is a bank note, ID card, chip card or the like.
  11. The data carrier of at least one of claims 1 to 10, characterized in that the areas (14, 16, 22) are strips disposed in columns each with a predetermined width.
  12. The data carrier of claim 11, characterized in that all strips (14, 16, 22) have the same predetermined width.
  13. The data carrier of at least one of claims 1 to 12, characterized in that all areas (14, 16, 22) have the same surface area.
  14. The data carrier of at least one of claims 1 to 13, characterized in that the orientation and/or basic geometry of the structural elements (12, 18) differ from each other in at least two contiguous areas (14, 16, 22).
  15. The data carrier of at least one of claims 1 to 14, characterized in that the predetermined number of structural elements (12, 18) is selected such that a moiré pattern is produced when the data carrier is scanned with a scanner.
  16. The data carrier of at least one of claims 1 to 15, characterized in that the structural elements of an area (14, 16, 22) do not directly touch the structural elements of an adjacent area.
  17. A data carrier, in particular document of value, according to at least one of the above claims, with at least one picture element represented by one or more structural elements (18), characterized in that the structural elements (18) are represented by means of screen lines (20) forming a screen structure.
  18. The data carrier of claim 17, characterized in that the screen structure is represented by means of a number of screen lines (20) which are essentially parallel within a structural element (18).
  19. The data carrier of claim 18, characterized in that the number of screen lines (20) is different between at least two structural elements (18).
  20. A method for producing a data carrier, in particular document of value, with at least one halftone image (10) represented by structural elements (12, 18), the structural elements having a basic geometry, and a predetermined size of the structural elements (12, 18) representing a gray level of the halftone image (10), characterized by the following steps:
    a) dividing a halftone image original into at least two contiguous areas (14, 16, 22),
    b) associating a number of structural elements (12, 18) with each area (14, 16, 22), the number of structural elements (12, 18) per unit area being different in at least two contiguous areas (14, 16, 22),
    c) associating the halftones present in an area with a structural element (12, 18) of defined size,
    d) applying the halftone image to the data carrier by applying the at least two areas (14, 16, 22) with the particular associated number of structural elements (12, 18) in the sizes corresponding to the halftones.
  21. The method of claim 20, characterized in that the structural elements are in particular printed using steel intaglio printing.
  22. The method of claim 20 or 21, characterized in that the structural elements are applied by means of a number of screen lines.
EP97940149A 1996-09-03 1997-09-01 Document with a moiré-effect-generating screen structure Expired - Lifetime EP0858400B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19635761A DE19635761A1 (en) 1996-09-03 1996-09-03 Document with moirE-generating raster structure
DE19635761 1996-09-03
PCT/EP1997/004745 WO1998009825A1 (en) 1996-09-03 1997-09-01 Document with a moire-generating raster structure

Publications (2)

Publication Number Publication Date
EP0858400A1 EP0858400A1 (en) 1998-08-19
EP0858400B1 true EP0858400B1 (en) 2002-12-11

Family

ID=7804526

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97940149A Expired - Lifetime EP0858400B1 (en) 1996-09-03 1997-09-01 Document with a moiré-effect-generating screen structure

Country Status (8)

Country Link
US (1) US6357800B1 (en)
EP (1) EP0858400B1 (en)
AT (1) ATE229441T1 (en)
AU (1) AU4208597A (en)
CA (1) CA2236326A1 (en)
DE (2) DE19635761A1 (en)
RU (1) RU2191118C2 (en)
WO (1) WO1998009825A1 (en)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6603568B1 (en) 2000-05-19 2003-08-05 Pitney Bowes Inc. System and method for issuing electronic tickets
US6373587B1 (en) * 2000-05-19 2002-04-16 Pitney Bowes Inc. Method for printing electronic tickets
FR2842460B1 (en) * 2002-07-19 2004-10-08 Arjo Wiggins SECURITY DOCUMENT PROTECTED AGAINST DUPLEX COPY
DE10243863A1 (en) * 2002-08-13 2004-02-26 Giesecke & Devrient Gmbh Data carrier, e.g. a banknote, with at least a security marking area to prevent counterfeiting in the form of an optically variable embossed structure with optically varying coatings arranged over the embossed area
US20070029394A1 (en) * 2005-08-01 2007-02-08 Wicker David M Covert document system
DE10346505A1 (en) * 2003-10-02 2005-01-05 Eckelt Glas Gmbh Light-permeable pane used in a composite glass pane for doors and for glazing a door filling has upper surfaces provided with a regular three-dimensional pattern which can be visually observed
RU2268152C9 (en) 2004-08-11 2006-05-20 Милимарекс Лимитед Printed matter and method for its manufacture (modifications)
US10343436B2 (en) * 2006-02-27 2019-07-09 Viavi Solutions Inc. Security device formed by printing with special effect inks
DE102006021961A1 (en) 2006-05-10 2007-11-15 Giesecke & Devrient Gmbh Safety element with laser marking
LT5868B (en) 2010-12-30 2012-09-25 Aleksej Zaicevskij Method of technical protection for printed products against copying
RU2503767C1 (en) * 2012-10-23 2014-01-10 Федеральное Государственное Унитарное Предприятие "Гознак" (Фгуп "Гознак") Counterfeit-protected data medium and method for production thereof
WO2017054852A1 (en) * 2015-09-29 2017-04-06 Hewlett-Packard Indigo B.V. Halftone screens
CN109249716B (en) * 2018-09-05 2020-09-15 深圳市裕同包装科技股份有限公司 Processing method of micro-lens true-color 3D printing image

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US15486A (en) * 1856-08-05 Improved blank for bank-notes, bills
FR2289992A1 (en) * 1974-10-31 1976-05-28 Opi Metriservice Sa SURFACE COLORING PROCESS
US4582346A (en) * 1984-05-08 1986-04-15 Moore Business Forms, Inc. Document security system
JPS6186300A (en) * 1984-10-05 1986-05-01 株式会社　ワイゼン Poster
GB8514158D0 (en) 1985-06-05 1985-07-10 De La Rue Thomas & Co Ltd Printed documents resistant to counterfeiting
US5074597A (en) * 1987-01-13 1991-12-24 The Lehigh Press, Inc. Computerized method of generating film masters for embossing and printing color images
GB8818431D0 (en) 1988-08-03 1988-09-07 Kenrick & Jefferson Ltd Copy protection of multi-colour documents
NL192610C (en) * 1990-12-13 1997-11-04 Enschede & Zonen Grafisch Image carrier and method for printing an image on an image carrier.
US5732163A (en) * 1993-07-21 1998-03-24 Northrop Grumman Corporation Angular alignment of structures using moire patterns
DE4446368A1 (en) * 1994-12-23 1996-06-27 Giesecke & Devrient Gmbh Data carrier with an optically variable element
US5987221A (en) * 1997-01-24 1999-11-16 Hewlett-Packard Company Encoded orphan pixels for discriminating halftone data from text and line art data

Also Published As

Publication number Publication date
RU2191118C2 (en) 2002-10-20
US6357800B1 (en) 2002-03-19
WO1998009825A1 (en) 1998-03-12
AU4208597A (en) 1998-03-26
DE59708947D1 (en) 2003-01-23
ATE229441T1 (en) 2002-12-15
CA2236326A1 (en) 1998-03-12
DE19635761A1 (en) 1998-03-05
EP0858400A1 (en) 1998-08-19

Similar Documents

Publication Publication Date Title
EP1325816B1 (en) Data carrier with an optically variable element
EP2040934B2 (en) Security element
DE69433395T2 (en) Security document with varying tint
DE19845436C5 (en) Intaglio printing method for printing adjacent color areas of different ink layer thickness, data carrier with printed image produced by intaglio printing, printing plate and method for producing a printing plate
EP0858400B1 (en) Document with a moiré-effect-generating screen structure
DE69917947T2 (en) NEW METHOD AND DEVICE FOR AUTHENTICATING DOCUMENTS BY APPLYING THE INTENSITY PROFILE OF MOIREMUSTER
DD228669A5 (en) SECURITIES, ESPECIALLY BANKNOTE, WITH A SAFETY PATTERN
WO2007006455A2 (en) Grid image and method for the production thereof
EP0779863B1 (en) Visually identifiable optical element
DE3602563C1 (en) Security paper with optically active structures generating a moiré effect
DE3437063A1 (en) METHOD AND ARRANGEMENT FOR DISPLAYING A HALFTONE IMAGE USING A DETECTIVELY ADAPTED GRID
WO1998007572A1 (en) Printed document protected against copying
EP1528987B2 (en) Data carrier
EP2941356B1 (en) Security document with security feature
EP3615349B1 (en) Method for producing a security element
DE60030066T2 (en) tester
EP0785874A1 (en) Structural arrangement, especially for a security component
EP3648983B1 (en) Optically variable security arrangement
DE102014001063A1 (en) Drainage screen for the production of paper with a watermark
DE3905155C2 (en) Data carrier, in particular security document with reproducible printed image in color copiers
DE102015114665B4 (en) Grid
AT398407B (en) Copy-protected printed products, film for their production by printing and method for identifying copies of printed products
DE2603558A1 (en) GRAPHIC PATTERN

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

17P Request for examination filed

Effective date: 19980914

17Q First examination report despatched

Effective date: 19991021

RTI1 Title (correction)

Free format text: DOCUMENT WITH A MOIRE-EFFECT-GENERATING SCREEN STRUCTURE

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20021211

Ref country code: IE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20021211

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20021211

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20021211

REF Corresponds to:

Ref document number: 229441

Country of ref document: AT

Date of ref document: 20021215

Kind code of ref document: T

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: CH

Ref legal event code: NV

Representative=s name: PATENTANWAELTE SCHAAD, BALASS, MENZL & PARTNER AG

GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

Effective date: 20021212

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: GERMAN

REF Corresponds to:

Ref document number: 59708947

Country of ref document: DE

Date of ref document: 20030123

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030311

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030311

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030311

ET Fr: translation filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20030627

ET1 Fr: translation filed ** revision of the translation of the patent or the claims
ET1 Fr: translation filed ** revision of the translation of the patent or the claims
REG Reference to a national code

Ref country code: IE

Ref legal event code: FD4D

Ref document number: 0858400E

Country of ref document: IE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030930

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030930

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20030912

BERE Be: lapsed

Owner name: *GIESECKE & DEVRIENT G.M.B.H.

Effective date: 20030930

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 20050919

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20050920

Year of fee payment: 9

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20070401

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20070401

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20070531

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20061002

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 20100920

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20101129

Year of fee payment: 14

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 229441

Country of ref document: AT

Kind code of ref document: T

Effective date: 20110901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110901

REG Reference to a national code

Ref country code: DE

Ref legal event code: R119

Ref document number: 59708947

Country of ref document: DE

Effective date: 20130403

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20130403

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20140922

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20140923

Year of fee payment: 18

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20150901

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150930

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150930

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20150901