EP1767381A1 - Article with optical effect - Google Patents

Abstract

An object with an optical effect in which the surface zone with the optical effect has at least two image patterns (12,14) lying one behind the other and with a change in the viewing angle, the optical perception of the complete image changes, where a first image pattern (12) is formed on the surface of a material layer (10), and the second image pattern (14) through holographic coding virtually lies in the apparent space (d) to the first (12) image pattern. An independent claim is included for application of an object in the form of a package.

Description

The invention relates to an article with a surface area which generates an optical effect to increase the security against forgery, wherein the surface area with the optical effect has at least two spaced-apart image patterns and the optical perception of the overall image generated by the superimposition of the image pattern changes as the viewing angle changes in which a first image pattern is arranged on the surface of a material layer and the image patterns are coordinated with one another in such a way that they show Moirö interferences.

The forgery-proof packaging is of great importance especially for the pharmaceutical industry. In principle, however, there is also a desire in other areas for forgery-proof packaging or products, in particular in the consumer goods industry, for example in the packaging of foods, cosmetic articles, clothing, software and music CDs or securities. The article having the optical effect-generating surface region may be a packaging, a packaging material, a packaging aid or a product itself, on which a surface area in the form of a security part, for example as a label, is provided with an optical effect.

A tamper evident packaging or packaging aid may serve as a tamper evidence guarantee that allows the customer to recognize that the product he has purchased has actually been manufactured and packaged by the desired producer. A tamper-resistant packaging aid can also be used, among other things, as a first-opening guarantee, for example in the form of a label, a banderole or a sealing strip, etc., for example over a bottle cap or over the closure of a wide-necked glass, over the seam between a lid and a container or over the zipper of a bag. When opening the appropriate packaging, the label, the banderole or the sealing strip is destroyed, indicating that an initial opening has already taken place. It is also possible, To fill or wrap items in an overpack, wherein the overpack has characteristic distinctive and non-duplicable features which show that the packaging of the contents has been made at a particular supplier.

Known anti-counterfeiting packaging and products are provided with holograms on their surface or have color codings or invisible features. In order to achieve a high security against counterfeiting u.a. Holograms proven. Examples are hologram labels or lidding films with integrated holograms. The production of individualized holograms is, however, associated with an enormous effort.

The US-A-4,662,653 discloses an article having a surface area comprising a transparent layer of material having an image pattern which is bounded on one side by a specular layer. The mirror image of the image pattern forms a second image pattern, the distance between these image patterns being determined by the thickness of the material layer. When the viewing angle changes, there is a change in the visual perception of the overall image generated by the superposition of the image patterns. The distances between the individual pixels or between the image pattern and the reflection layer are dimensioned so that the visual appearance is based on a light diffraction.

Also the US-A-4,632,430 discloses articles having a surface area producing an optical effect wherein two image patterns are spaced apart by a transparent layer of material and the optical perception of the overall image produced by the superposition of the image patterns changes as the viewing angle changes. This effect, which results only in translucent light, is based on a simple overlay of the shadow areas of the two image patterns.

An article known from FPA-0 348 583 includes a base surface with a line pattern. A transparent film is provided with a second Unienmuster. The transparent film having the second line pattern is partially fixed to the base surface, so that the distance between the base surface and the transparent film varies with different degrees of movement of the article. Under certain distance conditions arise for the viewer a kind of "dynamic" moiré pattern.

In the WO 97/19820 there is disclosed an article exhibiting on its surface an optical effect resulting from the arrangement of two image patterns separated by a transparent layer of material. The diffraction patterns produced by light diffraction on a microscopic raster image lead to moiré interference due to superimposition.

From the WO-A-98/15418 For example, there is known a paper which, when folded, has a surface area with an optical effect due to moiré interference. The two image patterns are each applied to a transparent film, the two image patterns have no fixed distance from each other, but one image pattern is arranged detached from the other. The optical effect therefore only occurs when the two image patterns are placed on each other during the folding of the paper.

From the DE-A-31 20 653 Moire strain gauges are known. The two image patterns (screen films) are not kept at a fixed distance from each other, but arranged separately from each other.

The EP-A-1 089 883 discloses an article having a surface area producing an optical effect to enhance anti-counterfeiting security, wherein the surface area having the optical effect has at least two image patterns fixedly spaced by a transparent layer of material, and when the viewing angle is changed, the optical perception of the overall image formed by the superposition of the image patterns which is defined by a thickness of the transparent material layer Distance between the image patterns and the distance between adjacent, the image patterns zugrufideliegenden pixels are coordinated so that the image patterns Moirä-Interforenzen show.

The invention has for its object to provide at least a portion of the surface of items such as packaging, packaging materials, packaging aids or products themselves with an optical effect that can be produced more cost-effectively compared to individualized holograms and its counterfeit security is greater from the EP-A-1 089 883 known optical effect based on the generation of Moire interference by arranging image patterns on both sides of a transparent material layer.

For the inventive solution of the problem results in an article of the type mentioned that the second image pattern by holographic coding is virtually at an apparent distance from the first image pattern.

The holographic coding of the second image pattern is preferably an embossing or etching hologram.

The invention makes from the EP-A-1 089 883 known phenomenon due to a three-dimensional moiré pattern use. Moire patterns are two-dimensional images resulting from interference from two overlapping grids. Shifting two superimposed grids also alters moiré interference, resulting in the familiar alternating chiaroscuro phenomena. In a three-dimensional moiré pattern, the change of moiré interference is produced without mechanical shifting of the rasters. Due to the mutual distance of the image patterns creates a spatial arrangement that leads to changing the viewing angle to changing moire interference.

The essential essence of the invention lies in the generation of a three-dimensional Moire pattern by superposition of a real and a virtual image pattern.

In order to produce the effect according to the invention, the distances already known from moiré patterns between adjacent picture elements must be observed. The image patterns may consist of individual parallel lines, be punctiform or contain a combination of straight and curved lines or other image patterns.

In the simplest case, the holographically encoded virtual image pattern is a uniform line pattern of individual parallel lines of equal distance between adjacent lines and the real image pattern is a pattern adapted to the virtual line pattern, preferably printed on the surface of the material layer. Firstly, the advantage of this arrangement is that the holographically coded, uniform line pattern always remains the same and thus eliminates the cost of generating individualized holograms, and secondly, register-accurate hologram moiré effects can be integrated into the print image. With the uniform line hologram virtually coded in front of or behind the surface and the printed image adapted to the lines, virtually any desired moiré images can be generated in the form of positive-negative-tilt images.

In a simple arrangement, the line hologram and the printed image adapted to the lines are arranged substantially congruently at a distance from each other. However, it is also possible to shift regions of one image pattern relative to the other image pattern, for example by half the distance between adjacent image elements, or to provide them with a different image pattern so that, for example, a multiple light-dark change results when the viewing angle changes. Of course, image patterns may also contain a combination of straight and curved lines or other picture elements. In this way it is possible, for example, brand names and the like. Signs with three-dimensional moiré effect to be installed in the packaging material. To further increase the security against counterfeiting, for example, one of the image patterns may contain an additional structure in addition to a line grid.

Another way to increase the security against forgery as well as the hidden arrangement of data is that by encoding additional information contained in the virtual lines. This additional information can only be obtained with a "lens", i. with a regular pattern, to be decoded. Such lenses consist of a grid pattern whose grid dimensions are matched to the screen dimensions of the virtual lines.

In one variant, the real image pattern is applied to an opaque film, for example on an aluminum foil.

In addition to the real and the virtual image pattern, another image pattern may be the mirror image of the real image pattern. In this case, the transparent material layer provided with the printed image is bounded on one side by a reflective layer, for example an aluminum foil with a high-gloss surface.

The image patterns can be monochrome or multicolored. As additional security colors can be used, which make the Moirö effect recognizable only in the UV or IR light. Another possibility is that the real image pattern is designed in the form of a surface structure with vertically offset structural parts, e.g. as a stamping or etching pattern.

Embossing or etching patterns are suitable, for example, for applying an image pattern on an aluminum foil. Embossing patterns can also be applied to plastic or aluminum / plastic laminate photographs by hot and / or cold stamping. Films or film laminates with a real image pattern in the form of a surface structure are particularly suitable for the production of tube laminates for the production of, for example, toothpaste tubes.

The image patterns may also comprise basic matrices with individual picture elements, wherein mutually associated picture elements of different basic matrices are offset from each other in order to produce locally different light-dark contrasts or colors. Preferably, the picture elements form patterns that result in defined light-dark contrasts or colors due to different combinations of overlays. Since these types of image patterns require an extremely high registration accuracy of the superimposed master matrices to achieve a good image effect, this type of image pattern is particularly suitable for applications in which high security against forgery is required.

The preparation of the article according to the invention is carried out by known processes. The security against counterfeiting is further increased by the fact that the application of the print image on a machine with high-precision print mark control must be carried out.

The article according to the invention can be, for example, any packaging material in the form of a packaging material or packaging auxiliary, which has a transparent material layer, wherein image patterns are additionally applied according to the invention. The packaging material may be rigid, semi-rigid or flexible and may be a molded article or, in particular, a film-shaped material. Examples of moldings are blown, deep-drawn and / or stretched or deep-drawn moldings, such as bottles, wide-necked vessels, cups, bowls or bottom parts of blister packs or blister packs. Examples of film-shaped materials are metal foils, such as aluminum, steel, copper, silver or gold foils. Other examples of sheet-like materials are papers, such as tissue paper with a basis weight of 20 to 30 g / m ² or white paper with a basis weight of 40 to 60 g / m ² , cardboard, semi-cardboard or the like. Of particular importance are plastic-containing films, for example based on Polyolefins, such as polyethylenes or polypropylenes, polyamides, polyvinyl chloride, polyesters, such as polyalkylene terephthalates and in particular polyethylene terephthalate. The plastic-containing films may be monofilms of plastics, laminates of two or more plastic films, laminates of metal and plastic films, laminates of papers and plastic films or laminates of papers and metal and plastic films. The individual plastic films may have a thickness of, for example, 12 to 200 .mu.m and the metal foils 12 to 100 .mu.m. The individual layers of the film-shaped materials can be adhesively bonded to one another by means of adhesives, laminating adhesives, adhesion promoters and / or by extrusion coating, coextrusion or laminating. Non-oriented or axially or biaxially oriented monofilms or laminates of two or more unoriented or axially or biaxially oriented films based on polyolefins, such as polyethylenes or polypropylenes, polyamides, polyvinyl chloride, polyesters, such as polyalkylene terephthalates and in particular polyethylene terephthalate, are preferred as the plastic films ,

The above-mentioned packaging materials may form the articles of the present invention in the form of packaging materials or auxiliary packaging materials. For example, from foil-shaped packaging materials by punching and sealing bags, sachets, wrappers, bags, etc. can be made. Films can be deformed by deep drawing and / or ironing to form packages or moldings, such as bottom parts of blister packs or blister packs or wide-mouth vessels, dishes, goblets, cups, etc. For example, tubes (laminate tubes) or covers for mold packs can be produced from the films. From, for example, carton-containing substrates, cartons, such as folding cartons, can be produced. It is also possible, for example bottles, blown from plastics, or to use preformed moldings as substrates and to attach the inventive material layer thereon. Closures, openings, seams, seams between a bottom part and the associated lid, etc. can be provided with a novel packaging aid in the form of a label, a sealing strip, a banderole, a warranty seal or a Überschliessung. These latter packaging aids are usually in the form of a film and are fixed on the corresponding container over the opening and on the adjacent container part, such as glued, welded, crimped or shrunk, etc. The packaging aid has the transparent material layer according to the invention and the image pattern held at a distance therefrom. The construction according to the invention of the surface or of a surface region of the object leads to the targeted optical appearance when the viewing angle changes. Falsification by photocopying and using the photocopy as a guarantee of originality or manufacturer would be immediately and easily recognizable, since a change in the viewing angle does not show the optical effect occurring in the structure according to the invention. So that packaging aids, such as sealing strips or bands, can be easily broken by the consumer, it may be appropriate to provide Anreiderhilfen such as weakenings, notches or Abreisszungen. It is also possible to use, as a constituent of packaging materials or packaging auxiliaries, easily tear-in or puncturable films, such as plastic films enriched with fillers or films produced from two poorly compatible plastic films.

In addition to the already mentioned use of the article according to the invention in the form of a packaging, a packaging material or a packaging material, another area of application is the forgery-proof production of securities, admission tickets and similar documents, whereby not only the counterfeit-proof design but also decorative special effects can be produced.

- Fig. 1

eine Schrägsicht auf ein virtuell hinter die Oberfläche einer Materialschicht codiertes Linienhologramm und ein an die Linien angepasstes Druckbild auf der Oberfläche der Materialschicht.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing; this shows schematically in

- Fig. 1

an oblique view of a virtually hologram encoded behind the surface of a layer of material line and adapted to the lines print image on the surface of the material layer.

FIG. 1 shows a transparent material layer 10 having a real image pattern 12 printed on the surface 11 of the material layer 10 and a virtual image pattern 14 holographically encoded behind the surface 11 at a distance d to the surface 11 on a virtual image plane 22 parallel to the surface 11 in FIG Shape of a built up of individual lines 18 grid. The lines 18 of the virtual image pattern 14 result due to an embossed hologram 20 transferred to the surface 11. The image elements 16 of the real image pattern 12 are adapted to the lines 18 of the virtual image pattern 14. The distance a between the individual grid lines 18 is always the same in the present example and corresponds to the resolution a. For the three-dimensional moiré effect, the critical angle α _{o is} decisive; if it is too large, large changes in angle are necessary for observation of the changing moiré interference, ie the effect is only weakly recognizable. The optimum value for the critical angle α ₀ is, for example, 20 °. The critical angle α _o is directly dependent on the distance d of the two image patterns 12, 14 and on the resolution a, the following mathematical relationship being true: $$\mathrm{a}\mathrm{=}\mathrm{d}\mathrm{\cdot }\mathrm{tg}{\mathrm{\alpha }}_{\mathrm{0}}\mathrm{,}$$

Due to the mathematical relationship between the distance d of the two image patterns 12, 14 and the distance a between the individual grid lines 16, 18, the distance d of the two image patterns 12, 14 for generating a print image with optimum resolution A can be determined in a simple manner.

The invention is not limited to the embodiments shown, but rather comprises all objects with a material layer designed according to the invention in at least one surface area. In particular, further films or films may supplement the material layer to any packaging material, or the inventive material layer may be attached directly to a product.

Claims (16)

The surface area with the optical effect has at least two spaced apart (d) each other image pattern (12, 14) and when changing the viewing angle (α), the optical perception of the superposition of the image pattern (12, 14) generated overall image changes, wherein a first image pattern (12) on the surface (11) of a material layer (10) is arranged and the image patterns (12, 14) are coordinated so that they Moird- Show interference
characterized in that
the second image pattern (14) lies virtually at the apparent distance (d) to the first image pattern (12) by holographic coding. An article according to claim 1, characterized in that the holographic coding of the second image pattern (14) is an embossing or etching hologram (20). An article according to claim 1 or 2, characterized in that the holographically encoded second image pattern (14) is a uniform line pattern and the first image pattern (12) is a pattern adapted to the uniform line pattern of the second image pattern (14). Article according to one of claims 1 to 3, characterized in that the first image pattern (12) on the surface (11) of the material layer (10) is printed. Article according to one of claims 1 to 4, characterized in that the material layer (10) is transparent. An article according to claim 5, characterized in that adjacent to the transparent material layer (10) is a shiny aluminum layer, in particular an aluminum foil with a high-gloss surface. Article according to one of claims 1 to 6, characterized in that at least one image pattern (12, 14) is colored. An article according to claim 7, characterized in that the first image pattern (12) is a visible only in UV or IR light color printing pattern. Article according to one of claims 1 to 8, characterized in that the first image pattern (12) is provided in the form of a surface structure with vertically offset structural parts. An article according to claim 9, characterized in that the first image pattern (12) is applied as a stamping or etching pattern. An article according to claim 9 or 10, characterized in that the first image pattern (12) is cold and / or hot stamped. Article according to one of claims 1 to 11, characterized in that regions of an image pattern (14) to the other image pattern (12) in particular by half the distance (a) between adjacent pixels (18) are shifted from each other. Article according to one of claims 1 to 12, characterized in that the image patterns (12.14) comprise basic matrices with individual pixels, wherein associated image elements of different basic matrices for generating locally different light-dark contrasts or colors are arranged offset against each other. An article according to claim 13, characterized in that the picture elements form patterns which result in defined light-dark contrasts or colors through various combinations of overlays. Article according to one of claims 1 to 14, characterized in that the second image pattern (14) contains information which becomes visible only after decoding with a grid pattern whose grid dimensions are matched to the dimensions of the image patterns (12,14). Use of an article according to one of claims 1 to 15 in the form of a packaging, a packaging material, a packaging aid, a security, an admission ticket or the like. Documents with a tamper-proof and / or visually appealing surface area.

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