SI9300679A - Security element for protecting of insuring documents against reproduction - Google Patents

Abstract

The invention concerns a protected document (1) such as a bank note, identity card or the like, with a security element (2) in the form of a band or strip which is subdivided into adjacent subsections in which diffraction structures are incorporated. The diffraction structures represent very reduced data. Data in individual sections can be read from different angles of view in such a way that when the angle of view is changed the optical data in various sections can be read in sequence, which creates the effect of movement along the length of security element (2).

Description

Security element to protect secured documents from reproduction

The invention relates to a secured document, such as a security note, card or the like, with a security element in the form of a ribbon or belt, the security element bearing structural structures containing visible and / or machine-identifiable information.

With the current state of the art of color copying technology, the risk of counterfeiting of documents, securities, checks, etc. is increasing. It is therefore desirable to protect the relevant documents with optical means that are well recognizable to the human eye but which cannot be reproduced by the color copier due to basic physical considerations.

Such a security element is described in EP-OS 0 238 043. The security described herein comprises a security thread consisting of a transparent material into which the structure of a cylindrical lens is imprinted on one side. A printed image is affixed to the side opposite the lens structure, taking into account the optical properties of the lenses. Depending on the angle of observation, different partial areas of this imprinted image are visible through the lens based on the collecting action of the cylindrical lenses and the position of the imprinted image in the focal plane. Proper design and placement of the imprinted image can produce a virtual movement of the imprinted image by rotating the document about an axis running parallel to the cylindrical lenses. This copying effect, which is due to changing viewing angles, cannot be reproduced by the copier, since it can only produce a momentary snapshot from a particular viewing angle. On the other hand, this safety element has the disadvantage that it must have a relatively large minimum thickness corresponding to the focal length of the lenses. Therefore, the security thread has a slight thickening that can become an obstacle to the processing of documents in bundles.

The alternative is holograms, which have been used for some time and have a thin-film construction and also offer good protection against counterfeiting with color copiers. Holograms are distinguished primarily by their special feature of faithfully producing complex spatial effects such that the observer detects different views of the pictorial information presented when changing the angle of their observation. This spatial impression is lost in copying because the copier, as already done in conjunction with EP-OS file 0 238 043, can only reproduce a hologram from one particular viewing angle. In order to make it difficult to imitate holograms and also to increase optical effects on value prints, today it tends to present visibly more complex and complex spatial structures.

Typically, holograms are made in the form of endless strips and are transmitted to the respective secured documents by means of a transmission technique (EP-A 2 0 420 261), the shape and size of the transmitted hologram being determined by the respective portable printer. The more complex and complex the pictorial information presented in the hologram, the greater the planar dimension of the hologram must be to ensure that the image information can be distinguished by the eye.

Particularly for securities subjected to heavy loads, the use of such planar holograms is problematic because the planar structure of the hologram is very sensitive to external mechanical influences.

As a rule, banknotes of many currencies contain security threads, which are either fully embedded in paper or like. security threads in windows directly accessible at certain intervals on the surface of the paper. Consideration was also given to anticipating holograms on such security threads (EP-OS 0 059 056). However, since the safety threads generally only have a width of 1 to 2 mm, the visible effects and thus the safety value of such hologram safety threads are very small.

Therefore, it is an object of the invention to propose a security with a thin security element in the form of a thread or ribbon, which offers good copy protection and allows easy visual inspection.

The solution to this task comes from independent patent claims. Further embodiments are the subject of dependent claims.

The invention is based on the idea that an increase in the holographic effect on the security thread can be achieved by reducing the presented information to a freely recognizable form and repeating this information, that is at least twice, to place it on the thread material so that changes in the viewing angle occur to the displacement effect.

In a preferred embodiment, the information is reduced to a light point and the security thread material is distributed in large numbers to each other in the following fields in which that light point is detectable at different viewing angles. In doing so, the angles of observation from field to field for low value are rising or falling. This rise or fall may be systematically followed by a predetermined pattern, e.g. ascending or. falling in the form of a sinus or monotonous.

When observing a secured document that has such a security element, each partial surface of the security element produces a focused light reflection that the observer can detect at a particular viewing angle. As the different partial surfaces differ in the angles of reflection, the observer can detect only one light point at a certain angle. However, the smallest movement of the document changes the angle of observation so that the light reflections of the other partial surfaces of the security element become visible to the observer. This gives the impression that the observed light reflection is apparently moving. Despite its small content, this effect is very pronounced and can be easily verified.

Further embodiments and advantages of the invention are explained on the basis of the figures.

In this, FIG. 1 is a secured document of the invention; 2 is a secured document of the invention in a first embodiment.

FIG. 1 shows a secured document 1 according to the invention, in this particular case a security having a security element 2 in the form of a thread. The thread shown is implemented as a security thread in windows. Alternatively, it can also be applied as a freely accessible strip on the surface of the security. In particular, with the window security design, it should be borne in mind that at least two adjacent areas are freely accessible to each window. DE-OS 40 36 637, to which it expressly refers, describes various procedures for applying security threads with dam structures of various widths, so that the procedure for making a security will not be discussed in more detail.

In FIG. 2 is an embodiment of the security thread 2 in the floor plan. The threads are divided into each other by the following fields 3, 4, 5, which remove light and from which it focuses the incident light in one or several predetermined directions. The deviation angles from field to field rise or fall, as illustrated in the illustration. Due to the different deflection angles, neither a small slope nor an impression of a light point moving along the safety thread is observed.

The effect of movement can be achieved by various known methods, that is, holographic, kinegraphic, or even the simplest effects of deflection on the retina.

If the deviation angle for box 4 is e.g. 0 °, that is, the deflection is perpendicular to the surface of the filament, increasing the deflection angle in the following fields in steps 2 to 3 °, it is sufficient to rotate the filament by only 10 ° to allow the light point to travel from the first to the fifth field. This means that the slight slopes of the safety thread or. the document attached to it is sufficient to allow the light point to travel along the thread up and down.

The sequence of angles can be selected as desired. Removable structures may be e.g. positioned such that the light point moves in the form of a wave along the safety thread. If a symmetrical arrangement of initially ascending and then descending angles is used, two points of light appear that, when the document is moved slightly, seemingly move towards each other or from each other.

According to the invention, there is image information in only one focal point of light, which, due to its brightness, can be easily found and clearly visible. Counterfeit security follows from the effect of the movement that occurs when the viewing angle or angle is changed. the slope of the document. This angle-dependent effect, as already described in connection with the treatment of the prior art, cannot be reproduced. Namely, the copier reproduces its directions of observation with the corresponding momentary snapshot of the security thread. That is, reflected and focused light beams, which can be captured by the copier optics, reproduce as bright and as a last resort white places, while the deflected structures whose reflecting directions lie outside the copier optics are depicted as black surfaces.

An individual light point can, in principle, be produced by holographic rendering of a point light origin. Based on this original hologram, embossing stamps can be made in a known manner. These stamps are now used to emboss the plastic film, which is then fitted over the entire surface with a reflective layer and cut into strips of the desired width that form the safety threads. As is generally known in the hologram technique, the reflective layer is a vaporized layer of aluminum, nickel, gold or titanium nitride. However, other materials may be used that are appropriate based on their reflective behavior.

It is also possible to first provide the plastic material with a reflective layer and only then imprint on it. In addition, the outline of boxes 3, 4, 5 need not be rectangular. Any form can be used, e.g. round or triangular leading to the effect of the invention.

Claims (8)

PATENT APPLICATIONS 1. A secured document, such as a security note, card or the like, with a security element in the form of a strap or belt, the security element having a structure of structure containing visible and / or machine-identifiable information, characterized in that the security element is divided into adjacent partial areas in which the structures are located, wherein the structures represent, after the statement, highly reduced information and the information of the individual parts of the area at different viewing angles is recognizable so that, when changing the viewing angle, the optical information of the different parts of the area for the other, and this may be interpreted along the security element as a displacement effect. A secured document according to claim 1, characterized in that the information presented is one or more focused light points. Secured document according to one of the preceding claims, characterized in that the security element is, in the longitudinal direction, neither spaced apart from one another by the adjacent rectangular partial regions. Secured document according to one of the preceding claims, characterized in that the viewing angles to the partial area under which the information can be observed differ by 2 to 3 °. Secured document according to one of the preceding claims, characterized in that the displacement effect is reflected in wave-shaped displacement. Secured document according to one of the preceding claims, characterized in that the effect of the movement is manifested in a monotonically increasing or increasing direction. to the falling movement. 7. Security element in the form of a thread or ribbon with structure structures comprising visible and / or machine-identifiable information for incorporation into secured documents, such as securities, cards or the like, characterized in that the security element is split into one another bordering partial regions in which the structures are located, wherein the structures represent highly reduced information by expression, and the information of the individual parts of the area is recognizable at different viewing angles so that, when the viewing angle is changed, the optical information of the different parts is recognizable to one another and this is explained along the safety element as a displacement effect. A method of producing a secured document, such as a security note, card or the like, with a security element in the form of a ribbon or belt, the security element bearing structural structures containing visible and / or machine identifiable information according to claim 1, characterized in that the security element shall be so placed in or on the document that, at each observer's view, it is freely accessible to each other by adjacent partial areas.