EP1272352B2 - Photoengraved printed data carrier - Google Patents

Abstract

Banknote paper has a printed surface (13) with print surfaces (14) within this print surface that are printed using an negative type printing process in which the paper is pushed at high pressure into engraved markings on the print plate that contain ink. Independent claims are made for a method for printing banknotes using such a negative type printing process, a print plate for use with such printing methods and a method for manufacturing the print plate using an engraving process.

Description

The invention relates to a method for producing a printed with the intaglio printing data carrier, using a printing plate suitable for this purpose.

Security and value documents, such as banknotes, stocks, bonds, certificates, vouchers and the like, which have to meet high demands regarding their security against counterfeiting, are often printed by intaglio printing. This printing process provides a characteristic, easily recognizable even for laymen print image that can not be readjusted with other popular printing processes.

In intaglio printing, areas are usually represented by a line grid, where line spacing and width determine the color tone or gray value of the area. The printed lines are usually a few tenths of a millimeter wide and each separated by unprinted areas. During the printing process, only the depressions introduced into the printing plate surface by means of etching or engraving are ink-conducting, while the actual printing plate surface is colorless. This is achieved by the printing plate surface is freed after inking by a wiping cylinder or a doctor of excess ink.

During the actual printing process, the data carrier to be printed is pressed against the printing plate by a pressure cylinder with an elastic surface at high pressure. The at least partially compressible data carrier, usually made of paper, is thereby pressed into the ink-filled depressions of the printing plate and thereby comes into contact with the printing ink. When detaching the disk from the printing plate this pulls the ink out of the wells. A printed image formed in this manner has spaced-apart printed lines or areas which are coated with a different thickness of color layer depending on the depth of the printing plate engraving.

Due to the high contact pressure, the substrate material additionally undergoes embossing, which also appears on the back of the data carrier. With sufficient depth of engraving in the printing plate receives a printed in intaglio printing medium by embossing and inking a printed image that forms a perceptible with the sense of touch relief. In the unprinted surface areas of the data carrier which are not covered with ink, the high pressures during the printing process act like calendering, which leads to a densification and smoothing of the data medium surface. These features make intaglio prints printable at any time from prints produced by other techniques.

The object of the present invention is to produce more complex printed images with increased protection against counterfeiting in intaglio printing.

This task is solved by the claim.

The data carrier produced in accordance with the invention is characterized by a surface printed in intaglio printing and at least one partial surface completely enclosed by this surface, wherein the surface and the partial surface are printed with the same printing ink but have a different ink layer thickness, so that they are visually contrasting. A character represented by the patch may be any geometric member, e.g. be circular, triangular or square or asymmetrical outline structure, an icon, characters or other symbol, with alphanumeric characters are preferred for characters in particular.

The printed area and the partial area enclosed by it are printed with a different thickness of color layer. Since conventional intaglio inks are somewhat translucent and translucent, color or gray tones of different brightness and color saturation result with suitable layer thicknesses and sensible choice of the color of the substrate. If there is sufficient difference in the ink layer thicknesses of adjacent areas, the human eye will see well visible contrasts without any further aids. Normal lighting conditions and a normal viewing distance are assumed.

The printed area and the area enclosed by it are in exact register with each other, if their position relative to each other is predetermined and is observed exactly and reproducibly without any slight deviations. When superimposing two printed images, which are produced by successive, independent printing processes, this register-accurate positioning of the two surfaces to each other is not possible.

In one embodiment, the printed area and sub-area are not only visually due to their contrast but also to the sense of touch, i. tactile, distinguishable. The surface relief created by the pressure consists of an embossing of the substrate material and the application of the paint coat. The overall height of the relief is set to the normal, i. unprinted and unembossed, data medium surface covered and amounts to at least 25 μm for tactile areas. Relief heights of more than 40 μm are particularly preferred, since surface elements with such relief heights are tactually particularly tactile.

The data carriers have increased security against counterfeiting, since they are not reproducible due to the characteristic intaglio image with common printing processes. If they also have tactile perceptible surface elements, this additionally provides effective protection against imitation by color photocopying or scanning of the data carriers.

In one embodiment, the printed surface of the data carrier additionally encloses unprinted subregions, which in turn may be in the form of one or more arbitrary characters. As a result, in addition to the two information reproduced in positive representation, that is to say with the application of paint, a third information item in negative representation, that is to say unprinted areas in a printed environment, can be reproduced in the same area.

According to one embodiment, the printed surface can also enclose several partial surfaces which either all have the same or different ink layer thicknesses. It is also possible to provide unprinted areas in the partial areas.

The shape of the faces can be chosen arbitrarily according to the invention, for example in the form of geometric patterns, logos or alphanumeric characters.

The various partial areas, unprinted areas and the outline of the printed area can also be in a sense context. Thus, it is conceivable, for example, to carry out the printed surface in the form of an alphanumeric character and to carry out the partial surfaces as well as possibly unprinted regions present in the printed surface and / or the partial surfaces in the form of the same symbol. If a plurality of printed areas are provided on the data carrier, which together represent readable information, such as a multi-digit number or a word, the partial areas and / or unprinted areas within a printed area can also be executed in the form of this overall information. But also any other contexts of meaning are conceivable.

The arrangement of the sub-areas within the printed area is arbitrary and is subject only to the restriction that the partial area or partial areas are largely enclosed by the printed area. If only a partial area is present within the printed area, then this can represent, for example, the same information as the printed area and extend parallel to the outer contour within the printed area. Preferably, however, a plurality of partial surfaces are arranged in the printed surface. The smaller the partial surfaces, the larger the number of these partial surfaces can of course be. These can be arranged in any pattern in the printed area. This pattern can also be readable information or even just a regular column and / or row arrangement. If additionally unprinted areas are provided in the printed area, these can be arranged alternately with the partial areas.

In the data carriers produced according to the invention, unprinted areas and areas with different ink layer thickness adjoin one another directly and in any desired order. This makes it possible to reproduce very complex printed images and to superimpose several information on the same surface, also in positive representation. The freedom of design in the creation and reproduction of printed images produced by the intaglio printing method is thereby increased enormously.

The method according to the invention for producing corresponding printed data carriers also has considerable economic advantages, since the areas provided for printing with different ink layer thicknesses are produced in one printing pass with the same printing ink. For printing by the method according to the invention are all suitable for intaglio printing substrate materials, such as paper, plastic films, laminated with plastic films or coated paper, and multi-layer composite materials.

The intaglio printing plates are preferably produced by engraving with a rapidly rotating, tapered stylus. According to the outline shape of the surface to be printed by the engraving corresponding depressions are introduced with targeted variation of the engraving depth in the surface of the printing plate and filled for printing with color. During printing, the ink is transferred from the wells of the plate to the surface of a substrate. From the untreated, i. not engraved surface areas of the printing plate is transferred no color. A deep engraving of the printing plate produces a high embossing relief on the printed substrate with a thick ink layer, whereas only a slight embossing relief with a thin ink layer is produced by flat engravings. If translucent colors are used, different color layer thicknesses result in visually contrasting printed areas, which are distinguishable even if they adjoin one another directly.

In order to prevent directly adjacent color layers, after they have been transferred to a data carrier, to flow into one another along their boundary line before the ink has dried, a so-called "separating edge" is integrated in the printing plate between surfaces having different engraving depths. This separating edge has a tapered, wedge-shaped cross-sectional profile. The tip of the wedge is preferably at the level of the printing plate surface or slightly below.

The tip of the separating edge profile forms a largely one-dimensional line along the separating edge, similar to a knife edge. Although it separates the printing plate areas of different engraving depths from each other, but does not produce visible interruption of the printed color areas. With the support of the separating edge integrated in the printing plate, the intaglio printing ink, which has a pasty consistency, also remains dimensionally stable after it has been transferred to a substrate when surfaces printed with different layer thickness directly abut one another. In this way, in intaglio printing, the finest, superimposed structures with different Color layer thickness and high edge sharpness to be printed.

When engraving the printing plate, the engraving tool is guided so that a tapered separating edge stops between the adjoining surfaces, which have a different engraving depth. If a printed partial area of a likewise printed surrounding surface is completely enclosed on the substrate, the indentation or engraving of the printing plate corresponding to the partial area must be completely enclosed by a separating edge.

If the engravings of the printing plate are not inked before printing or at least partially not filled with printing ink, the non-inked area of the printing plate acts only as an embossing plate with which so-called blind embossings can be produced on a substrate during the intaglio printing. The embossed elements, with the exception of the visual impression created by the ink, have similar proportions and tactile properties as the previously described printed areas and patches.

Further embodiments and advantages of the invention are explained below with reference to the figures. The variants described in the exemplary embodiments relate primarily to very small partial surfaces. Of course, the printed surface according to the invention as well as the partial surfaces can be larger, d. H. be carried out a few millimeters to centimeters. The integration of unprinted areas in the printed area in the following embodiments is not the subject of the invention.

Fig.1

eine Banknote in Aufsicht,

Fig. 2, 3a, 3b und 4

Ausschnitte bedruckter Datenträger im Querschnitt,

Fig. 5

einen Stichtiefdruck in Aufsicht mit zwei überlagerten Informationen,

Fig. 6

einen weiteren Stichtiefdruck in Aufsicht mit drei überlagerten Informationen,

Fig. 7a, 7b und 8

Stichtiefdrucke in Aufsicht mit überlagerten Informationen und Flächen unterschiedlicher Farbschichtdicke,

Fig. 9

einen weiteren Stichtiefdruck in Aufsicht mit überlagerten Informationen in Positivdarstellung.

Show it:

Fig.1

a banknote in supervision,

2, 3a, 3b and 4

Cutouts of printed media in cross section,

Fig. 5

an intaglio printing in supervision with two overlaid information,

Fig. 6

another intaglio printing in supervision with three overlaid information,

FIGS. 7a, 7b and 8

Intaglio printing with superimposed information and areas of different color layer thickness,

Fig. 9

another intaglio printing in supervision with overlaid information in positive representation.

In Fig. 1 is sketched as a disk 1 a banknote. A banknote usually has different types of imprints. The banknote shown, for example, shows a printed image 5, by which a portrait image is indicated. This print image 5 is converted by conventional intaglio printing, which means that different color tones or brightnesses are represented by line rasters with varying line spacing or varying line width. Furthermore, there is a background pattern 7 of fine lines produced in offset printing and a serial number 8 applied by letterpress printing.

The imprint according to the invention is provided in the example shown here only in a partial region of the banknote and consists of a completely printed with color surface 2, which completely encloses a likewise printed with a closed ink layer surface 3. The surfaces 2 and 3 were printed in intaglio with differently thick layers of paint, whereby they are visually distinguishable, since there is a brightness or color contrast between the surface 2 and the sub-area 3. In addition, the printed surface encloses 2 unprinted portions 4, by the corresponding design of the unprinted areas 4, a further information can be conveyed.

In contrast, according to the prior art, information is presented only as printed areas in front of an unprinted background, ie in a positive representation, or as an unprinted area in front of a printed background. Fig. 2 shows a printed according to the prior art volume area in cross-section, in which a substrate 9 was printed in spaced-apart surfaces 10 with ink. In the case of positive representation, the actual information is reproduced by the printed areas 10, which stand out with a high contrast from the unprinted surroundings 11 and 12. In the negative, the information is represented by the unprinted surface areas 11, while the printed areas 10 form the environment and enclose the information-conveying unprinted areas 11. The ink-bearing surfaces 10 are in conventional intaglio printing usually lines with a width of significantly less than 1 mm.

The Fig. 3a and 3b illustrate the principle of the invention to represent information in a continuously printed area by targeted variation of the ink layer thickness between two layer thickness levels. The Fig. 3a and 3b show a printed according to the invention volume area in cross section. In the partial surfaces 14, which are not completely enclosed by the surrounding pressure surface 13 in the cross section, the ink layer thickness changes so clearly that a visually easily perceivable color or brightness contrast arises between the surfaces 13 and 14. In Fig. 3a the faces 14 have a larger compared to their environment Paint thickness on while in Fig. 3b the reverse case is shown, ie the surrounding surface 13 is printed with a thicker ink layer than the partial surfaces 14. If a translucent printing ink is used to produce the surfaces 13 and 14, the surfaces with the lower ink layer thickness appear in a lighter shade. In this case, the in Fig. 3a shown as darker areas against a brighter background, while the in Fig. 3b shown partial areas 14 appear in a lighter shade than the surrounding printed surface thirteenth

Thus, information can be represented by printed, ie color-carrying partial surfaces 14 in front of a likewise color-carrying environment 13. If information is also imparted by the shape and outline of the printed surface 13, two superimposed information can be reproduced in positive representation on the same surface.

Fig. 4 also shows a section of a data carrier according to the invention in cross section. Here, in the printed area additionally unprinted portions 15 are integrated, which - again not visible in section - are completely enclosed by the printed surfaces 13 and 14. With appropriate design of the unprinted areas 15 can be represented by these areas a further, additional information in a negative representation.

The following Fig. 5 to 9 show enlarged representations of various preferred embodiments of the invention in a plan view. For reasons of clarity, only the printed image produced according to the invention in intaglio printing is shown. The size ratios of the surfaces and partial surfaces to each other are reproduced realistically.

In Fig. 5 the number 2000 is reproduced, each individual digit being represented by a printed surface 13 according to the invention, which has a closed ink layer of specific layer thickness. Each printed area 13 representing a number contains partial areas 14 which are enclosed on all sides and which have been printed with a thicker color layer and therefore appear darker. The outline shape of the partial surfaces 14 is selected in this example so that a digit is also represented by each partial surface 14. In Fig. 5 is reproduced by the number sequence of the partial surfaces 14, the same number as reproduced by the succession of the individual pressure surfaces 13. Of course, any other characters, patterns or symbols can be used. If the surfaces 13 are printed with a printing plate in the corresponding areas, for example, an engraving depth of z. B. 15 microns, while the partial surfaces 14 corresponding portions of the printing plate, for example, with an engraving depth of z. B. 100 microns, results between the surfaces 13 and 14 of the disk not only a visually good perceptible contrast, but also a tactile level difference. Because printed by deep engraving faces 14 create on the disk a raised relief that can be clearly perceived by pressing the fingertips.

In Fig. 6 is reproduced by the outline shape of the printed areas 13, the number 20. Each of the two surfaces 13 represents a number and each contains sub-areas 14, which are printed with a larger ink layer thickness and are therefore perceived darker. Due to the shape of the partial surfaces 14, the number 20 is also reproduced. In addition, the areas 13 printed with the thin ink layer surround unprinted partial areas 15, which are designed so that they likewise represent the number 20. As a result, three pieces of information are displayed on the same area, the contents of which correspond in the present example. Two pieces of information are displayed in a positive representation, while the third piece of information is displayed in negative. The unprinted areas 15 are arranged net-like within the printed area 13 and frame each partial area 14.

In preferred embodiments according to the illustrations in FIGS Fig. 5 and 6 have the reproduced by the printed areas 13 characters height or size of about 1 cm. Signs of this size are still legible even at large viewing distances. By the enclosed partial surfaces 14 characters are preferably reproduced with a size of about 1 mm. Signs of this size are still legible at normal viewing distance of about 20 to 50 cm with the naked eye. If additional characters are integrated by unprinted subareas, they are preferably executed as micro-writing. The preferred character size is only a few tenths of a millimeter. Such microfonts are easily readable only with the aid magnifying aids, such as a magnifying glass and represent an additional security feature, because such fine structures of commercially available photocopiers and scanners are not resolved with sufficient accuracy.

In the Fig. 7a and 7b Two print images are shown, in which the printed areas 13 reproduce both characters (the numbers 2 and 0) and a geometric element (a square). The printed partial areas 14 of this embodiment represent a surface relief which is particularly strongly formed by embossing and paint coat application and are therefore tactile perceptible. The information represented by the partial surfaces 14 here corresponds to a simple geometric element in the form of a circle.

In particular, structures with a geometrically simple contour are suitable as tactile elements that can be particularly well perceived. The size of the tactile elements is preferably a few millimeters and they preferably have a distance of at least about 0.5 mm from each other. The unprinted partial surfaces integrated into the printed surface 15 in Fig. 7a the number 20 again. A further preferred, but not reproduced in the figure variant is to reproduce in the printed area 13 by numeral 2 by unprinted faces 15 only the same number 2 and accordingly in the number 0 represented by the surface of the unprinted surfaces 15 also as number 0 form.

In Fig. 7b the unprinted areas 15 have the shape of characters that follow one another in a row and form a microwriting. Their information content differs from the information content represented by the printed areas 13 and partial areas 14. A micro-font line reproduced in a negative representation is followed by a line in which the circles reproduced by partial areas 14 with a thick color layer follow one another. In Fig. 7a On the other hand, the characters represented by the unprinted areas 15 and the printed areas 14 are arranged so as to follow each other alternately in both the vertical and horizontal directions.

In Fig. 8 For example, the unprinted areas are arranged in the printed area such that there are first unprinted areas 16 which are enclosed by a printed area with a low ink layer thickness, in this case by the printed area 13, and second unprinted areas 17, which are separated by a Color surface are enclosed with a large ink layer thickness, here the sub-areas 14. In Fig. 8 The first unprinted partial surfaces 16 represent the numerals 5 and 0. The second unprinted partial surfaces 17, like the printed dark partial surfaces 14, are designed as a square.

In Fig. 9 For example, the printed dark areas 13 represent the numerals of the number 50, the visual dark impression being mediated by a thick layer of paint. The partial surfaces 14 enclosed by the printed surface 13 have the form of letters, which together form the repetitive word "EURO" followed by a "$" symbol in each case. They are lighter as they are produced by a thin layer of paint. The information that is formed within the printed surface 13 of the partial surfaces 14 also extends into the environment of the printed surface 13. In the example shown, the characters formed within the printed surface 13 of the printed partial surfaces 14 also extend in the unprinted environment of the surface 13. This variant can also be used in the other embodiments.

Claims (1)

1. A method for producing a printed data carrier, in particular bank note, paper of value or the like, wherein a substrate is printed by intaglio printing, there being applied to a surface and at least one partial surface enclosed thereby, in a printing operation, a printing ink in different ink layer thickness, so that the continuously printed surface and partial surface are visually distinguishable from each other, and the printing operation is effected employing a printing plate with depressions provided for receiving ink in the surface thereof,
   whereby the surface taken up by a depression completely encloses at least one partial surface, and the partial surface has an engraving depth that differs from the engraving depth of the surface, and the partial surface is enclosed by a tapered separation edge having a wedge-shaped cross-sectional profile.

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