EP0920383B1 - Printed document protected against copying - Google Patents

Abstract

A security print contains a background pattern formed for example of dots or lines. An object, for example the text "BEWARE OF FORGERY", is worked into this regular background pattern for copy protection. The text is worked in by the individual lines of the background pattern being split at the places where the text is located into two partial lines which are each only about half as wide as the original line. With the naked eye this split of the background pattern components is not, or barely, recognizable. When such an original security print is copied on a conventional copying machine the original, relatively wide lines of the background pattern appear on the copy but the partial lines formed by the split thereof are not, or very poorly, copied so that the text "BEWARE OF FORGERY" appears clearly in the copy.

Description

The invention relates to a document with copy-protected security printing with an essentially regular background pattern from lines, dots, grid structures or the like.

As is well known, documents to be secured against forgery are made with fine Printed patterns that have a background for other printing information represent. The background then consists, for example, of sets of lines, Guilloche patterns, dot patterns, grid structures and the like. Then on this more or less regular background pattern Information printed on, for example texts, logos, numbers.

Such security printing can be monochrome or colored his. A colored security print is compared to a black and white print to be preferred because it is less easy to copy. However, there are already highly developed color copiers today, too colored security prints are deceptively real to copy. There are numerous measures to counterfeit printed documents prevent or complicate.

From US-A-4 175 774 is a document with a security print known, in which on an original document first areas with relative large dots and second areas with relatively small dots are. The small dots are so small that when you copy the Original documents are not copied on a copier, however the large dots appear in the copy. This will help Consider the copy on that it is not an original, but is a copy. The only differentiator between The first and second areas of this state of the art hence the point size.

The object of the present invention is to provide a document with a Security printing and a method for producing such a document not specify that on a commercially available photocopier can be copied without immediately recognizing that it is a Copy acts.

According to the invention, this object is achieved with a document a copy-protected security print, in which an essentially regular background pattern of lines, dots, grid structures or the like at least one object, for example letters, Digits or the like is incorporated in that the components of the background pattern a line is split at the locations occupied by the object So split into several partial lines or a full circle to form a ring is.

The one formed, for example, by a large number of parallel fine lines The background is usually only perceived as "gray" when viewed briefly, The individual lines of the Background pattern recognizable as such. The same applies to others Background pattern, such as a pattern of dots, rectangles, Diamonds or a combination of such background pattern components.

According to the invention, these components of the background pattern are now on "split" in places where the "object" is incorporated. "Object" here means any character or a combination of Characters, for example individual letters, texts, numbers, logos and like.

The term "split" means that a coherent printed Area, for example a line, separated in such a way divided, i.e. "Split" is that from the contiguous area at least two sub-areas will be a coherent Line is therefore replaced by two, three or more sub-lines. The total width a group of two or more sub-lines is not essential wider than the contiguous one replaced by the partial lines Line.

Even with a feature size, for example a line width, of less than 150 microns, preferably less than 100 microns, are according to one aspect of the invention incorporated into the background pattern Objects practically imperceptible to the naked eye. Will be one Print copied with a commercially available copier, so come indeed the already thin lines, dots and the like of the Background pattern also clearly on the copy, but in the places where the components of the background pattern are split, that is, at the locations of the object, is the Poor copy. Depending on the quality and functionality the copier, the object appears much brighter than the rest Background pattern, in some places are the partial lines, partial points and such things have not been copied at all, that is, at these points the object appears completely white, for example if you have one Black and white security print and its copy considered. Naturally in practice you will find such "objects" in the background pattern work in so that the viewer immediately realizes that it is a Copy acts, and does not assume that the "object" belongs to the original print. It is useful, for example, to use the word "copy" as "object" or to incorporate "fake" or the like into the background pattern. This word is then immediately recognizable on the copy.

For background patterns consisting of lines, sets of lines, line groups and the like or contain such lines, it has proven to be Proven and sufficient for copy protection, the individual Lines at the locations occupied by the object in two partial lines split, preferably the thickness of each sub-line about the half the line width of the original line. Preferably with two sub-lines per line, the width of each sub-line is approximately 40 to 45% of the original line width, and the distance between the partial lines in pairs is between one third and two thirds the original line width.

Instead of lines, the background pattern can also have dots, that is full circles alone or in combination with lines, rectangles and other background pattern components. At the points that is, full circles in the background pattern are split in such a way that the full circle is replaced by a ring, whereby the area of the ring corresponds to approximately 50 to 150% of the circular area, preferably between 85 and 115%. The thickness of the ring that is the difference between the outer radius and the inner radius of the ring, corresponds to about half the diameter of the full circle.

These guidelines can also be applied to other types of background patterns transferred, for example to squares. A full square leaves replace yourself with a square ring or frame, the stroke width is then chosen so that the area of the frame is about that of the full square. Other possible patterns are rhombuses, Ellipses and the like. These patterns can also be almost any combine.

It has been shown that this becomes clear to the naked eye Hardly recognizable "object" by copying the security print from the type of copier and also the orientation of the background pattern with respect to the scanning direction of the security print on the Copier depends. Doing some experiments with an inventive Security printing and a commercially available copier and rotates the security print on the document glass plate with every copy process one piece, you can see that the "object" is not every copying process appears equally strong.

Now about the copy protection in the security printing according to the invention to optimize, especially in connection with a line Background pattern, is the orientation of the background pattern preferably varied continuously or stepped between 0 ° and 360 °. With such security printing, some objects or some come Sub-areas of an object may be expressed less clearly, other object for it the stronger. In any case, the copy immediately recognized as such.

a) Bereitstellen von Druckinformation für das Hintergrundmuster;

b) Bereitstellen von Ortsinformation für das einzuarbeitende Objekt;

c) Bereitstellen einer modifizierten Druckinformation, welche die Druckinformation für das Hintergrundmuster stellenweise zu ersetzen vermag, und die zusammenhängenden Bestandteile des Hintergrundmusters ersetzt durch aufgespaltene Bestandteile; und

d) Kombinieren der Informationen gemäß a), b) und c) derart, daß die Druckinformation für das Hintergrundmuster an solchen Stellen durch die modifizierte Druckinformation ersetzt wird, an denen sich das Objekt befindet.

The invention also relates to a method for producing a security print, comprising the following steps:

a) providing printing information for the background pattern;

b) providing location information for the object to be incorporated;

c) providing modified print information which can replace the print information for the background pattern in places and replace the connected components of the background pattern with split components; and

d) Combining the information according to a), b) and c) such that the print information for the background pattern is replaced by the modified print information at those locations where the object is located.

With the help of this method, for example a laser engraving system a print template for an inventive Create security printing. The print template can also be produced of a film with the help of a film setter and subsequent transmission of the film information. In A memory is the for the entire area of a security print original information about the background pattern is saved. In the print information about the object is stored in a further memory, for example the word "FAKE", which is on a certain place or several places of the security printing incorporated shall be. The memory contents are then overlaid in the Way that at the locations of the object, the print information for the Background pattern is replaced by modified print information, according to the for example contiguous lines parallel partial lines are replaced. After this incorporation of the object in the background pattern, the print template is then created.

Fig. 1 eine Darstellung der Art und Weise der Fertigung einer Druckvorlage für einen Sicherheitsdruck gemäß der Erfindung, wobei unten in Fig. 1 der fertige Sicherheitsdruck abgebildet ist;

Fig. 2a bis 2d teilweise in unterschiedlichem Maßstab dargestellte Ausschnitte aus einem Sicherheitsdruck, bei dem das Hintergrundmuster durch ein Punktraster gebildet wird;

Fig. 3 eine stark vergrößerte Linie eines Hintergrundmusters;

Fig. 4a bis 4e verschiedene Möglichkeiten der Aufspaltung von Bestandteilen eines Hintergrundmusters; und

Fig. 5 einen Sicherheitsdruck mit Linien-Hintergrundmuster in verschiedenen Orientierungen.

Exemplary embodiments of the invention are explained in more detail below with reference to the drawing. Show it:

1 shows an illustration of the manner in which a printing template for a security print according to the invention is produced, the finished security print being shown below in FIG. 1;

2a to 2d show sections of a security print, partially in different scales, in which the background pattern is formed by a dot screen;

3 is a greatly enlarged line of a background pattern;

4a to 4e different possibilities of splitting components of a background pattern; and

Fig. 5 shows a security print with line background pattern in different orientations.

The security pattern according to the invention can be different Manufacture printing processes. In the present case it is called Example assumed that a printing roller or plate by film exposure is created, for which purpose a film with an imagesetter (image setter) and then transfer the information from the film template becomes. The preparation of the print information for security printing then includes the incorporation of "objects" into the background information.

As shown in FIG. 1, the desired background pattern information is first provided for the preparation of the print information, and the information about the object to be incorporated into the background pattern is also created. In the present case, the "object" should be a text, namely the repeatedly repeated text "BEWARE OF FORGERY". The combination of the information about the printing of the background pattern and the object "BEWARE OF FORGERY" is shown clearly in FIG. 1. The text "BEWARE OF FORGERY" does not actually appear in the print, but in the manner to be explained below, the text "BEWARE OF FORGERY" is incorporated into the background pattern consisting of slightly wavy lines in such a way that the text with the is practically invisible to the naked eye.
This is shown at the bottom right in FIG. 1. As you can see, the "combination" of background pattern and object does not contain any information that is immediately recognizable to the naked eye.

At the bottom left in Fig. 1 is a greatly enlarged section of the Security printing shown. In this section you can see at a closer look at the letter "B". The information of the letter "B" is formed by the fact that at the relevant points of the Object "B" split the lines of the linear background pattern are in two thin lines. The sub-lines each have one Thickness equal to 40% of the original line weight, with the Gap between the paired sub-lines 50% of the original Line width corresponds. If you look at the letter "B" on the left viewed from below at a distance of a few meters the "B" as such practically no longer recognizable, just like in the original size security print on the right any information can be seen at the bottom of FIG.

If now the security print shown at the bottom right in Fig. 1 copied on a commercial copier appear on the Copy the lines of the original background pattern, though these lines here have a thickness of 100 µm, those areas however, in which the components of the background pattern appear in pairs Partial lines are split, appear white or at least essential lighter than the rest of the background pattern. This is too in Fig. 1 recognize where (in the case of another one, to be described below Exemplary embodiment) the word "FORGERY" and the letter "F" is clearly visible while these "objects" are in the original security print are not recognizable.

In the example shown in FIG. 1, the text "BEWARE OF FORGERY "the object to be incorporated into the background pattern, which is not in the original security print, but in one of them drawn copy appears clearly. Of course you can as "Object" also does not match that of the text "BEWARE OF FORGERY" Take up the occupied background so that only this one in the middle in FIG. 1 Gray appearing background with split lines executed while the areas in which the "object" is located with solid lines. With a copy appears then of course the background is bright, and the "BEWARE OF FORGERY "occurs in the original grayscale of the background pattern in appearance.

The embodiment explained with reference to FIG. 1 fulfills the task not only with black and white copiers, but also with color copiers.

2a to 2d show a second embodiment of the invention. The The background pattern is a grid of dots made up of small, full circles. The Object "T" is shown in Fig. 2a overlapped with the background pattern.

2b shows the object "T" incorporated into the background pattern Form of small rings, each a full circle of the background pattern replace.

FIG. 2c shows an enlarged detail of FIG. 2b. It is shown in Fig. 2c two upper rows and a left column made of full circles. The four elements at the bottom right in Fig. 2c are parts of the in the Background pattern of incorporated object.

FIG. 2d shows an enlarged detail of FIG. 2c. Above in Fig. 2d the full circle 10 from FIG. 2c is shown, the bottom in FIG. 2d is the Ring 12 shown in Fig. 2c, this ring by "splitting" of the full circle.

The diameter d1 of the full circle 10 is approximately twice the thickness, that is to say the difference between the outer radius and the inner radius of the ring 12 (d1 ≈ 2 • d2).
The area A1 of the full circle 10 corresponds approximately to the area A2 of the ring 12.

Fig. 3 shows part of a line L and a pair of sub-lines TL corresponding to the detail at the bottom left in Fig. 1. The original Line width is w1. Where the line divides into a pair of sub-lines, TL, split, are the outer edges of the part line pair slightly offset to the outside. Each sub-line has a thickness w2, the clear distance between the parallel partial lines is w3. It has proven to be useful if the two sub-lines have the same width w2 and the value of w2 is approximately 40 to 45% of the original Line width corresponds to w1.

4 contains representations of some alternative background patterns.

4a schematically shows once again the embodiment according to FIG. 3, in which a line is split into two parallel sub-lines.

Fig. 4b shows the embodiment of FIG. 2, in which a full Circle is split into a ring of approximately the same area size.

4c shows a further embodiment in which the background pattern is formed by a grid of full squares. To the The full square is replaced when placing an object to be incorporated through a square ring or square frame. The area the frame corresponds approximately to that of the full square.

4d shows a diamond-shaped component of a background pattern, which is split up into an object hollow rombus, here too the dimensions are chosen so that the area of the original background pattern component and split part of the background pattern about the same size are. The "line width" of the split shown in Fig. 4b, 4c and 4d Elements corresponds to about half the diameter or the width / length of the original element.

4e shows a further embodiment of the invention. Here it is original line patterns not to two, but to three parallel ones Split partial lines. Still other background patterns with corresponding ones Splits are conceivable.

As explained above, those are incorporated into the background pattern Objects practically invisible to the naked eye, they only come in the one drawn from the original security print Copy appears. How strong the object appears in the copy comes depends, among other things, on the nature of the copier and the orientation of the background pattern with respect to the light scanning direction in the copier. To make security printing independent to make of such influences is a linear Background pattern this arranged in different orientations. 5 shows a security print with a linear background pattern, the background pattern divided into five segments is. The main direction or orientation of the runs in each segment Lines of the background pattern in a different direction. All in all are the lines of the background pattern from sector to sector by 72 ° added. The letter T can be seen in FIG. 5 above, which in all five sectors according to the orientation of the lines of the background pattern is incorporated depending on how the original security print is on the copier's original glass plate is oriented, the individual steps Objects in different sectors in different degrees Appearance.

Claims (10)

1. A document with a copy-protected security print wherein at least one object, for example letters, numerals and the like, is worked into a substantially regular background pattern of geometric elements such as lines, dots, screen structures or the like by solid geometric elements being converted into hollow geometric elements, e.g. a line being converted into a plurality of partial lines, or a solid circle into a ring.
2. A document according to claim 1, characterized in that the background pattern components have a width of no more than 150 microns, preferably 100 microns.
3. A document according to claim 1 or 2 with a background pattern consisting of families of lines, characterized in that the lines are each converted into two or more partial lines at the places occupied by the object.
4. A document according to claim 3, characterized in that the two partial lines each have about half the line width (d1) of the original line.
5. A document according to claim 3 and 4, characterized in that the partial lines each have about 40 to 45% of the original line width.
6. A document according to any of claims 3 to 5, characterized in that the distance between paired partial lines is between one third and two thirds of the original line width (w1).
7. A document according to claim 1 or 2 with a dot pattern of solid circles as a background pattern, characterized in that at the places occupied by the object the solid circles are formed as rings whose area (A2) corresponds to 50...150% of the area (A1) of a solid circle, preferably 85...115% of the area of a solid circle.
8. A document according to claim 7, characterized in that the thickness (d2) of the ring (12) corresponds to about half the diameter (d1) of a solid circle (10).
9. A document according to any of claims 1 to 8, characterized in that the background pattern contains families of lines whose orientation is varied continuously or in steps between 0 and 360°.
10. A method for producing a security print on a document according to any of claims 1 to 9 wherein at least one object, for example letters, numerals or the like, is worked into a substantially regular background pattern of geometric elements such as lines, dots, screen structures or the like, characterized by the following steps:

    a) supplying print information for the background pattern;

    b) supplying positional information for the object to be worked in;

    c) supplying modified print information which is capable of replacing the print information for the background pattern in certain places, and replaces the solid geometric elements of the background pattern by hollow elements; and

    d) combining information a), b) and c) in such a way that the print information for the background pattern is replaced by the modified print information at the places where the object is located.

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