Source: https://patents.google.com/patent/EP2162294B1/en
Timestamp: 2020-01-29 17:27:48
Document Index: 54230679

Matched Legal Cases: ['arts 28', 'arts 28', 'arts 28', 'arts 80', 'arts 80', 'arts 80']

EP2162294B1 - Security element - Google Patents
EP2162294B1
EP2162294B1 EP08784548A EP08784548A EP2162294B1 EP 2162294 B1 EP2162294 B1 EP 2162294B1 EP 08784548 A EP08784548 A EP 08784548A EP 08784548 A EP08784548 A EP 08784548A EP 2162294 B1 EP2162294 B1 EP 2162294B1
micromotif
EP08784548A
EP2162294A2 (en
2008-06-25 Priority to PCT/EP2008/005173 priority patent/WO2009000529A2/en
2010-03-17 Publication of EP2162294A2 publication Critical patent/EP2162294A2/en
2012-03-21 Publication of EP2162294B1 publication Critical patent/EP2162294B1/en
230000000737 periodic Effects 0 abstract claims 24
The invention relates to a security element (16) for security papers, value documents and the like, comprising a microoptical magnification system of the moiré type for representing a moiré image (84) having one or more moiré image elements (86); a motif image that contains a periodic or at least locally periodic arrangement of a plurality of grid cells (24) having micro-motif image components (28, 28', 28''), a focusing element grid (22), interspaced from the motif image, for the moiré-magnified viewing of the motif image, comprising a periodic or at least locally periodic arrangement of a plurality of grid cells having respective mcirofocusing elements (22), the micro-motif image components (28, 28', 28'') of a plurality of interspaced grid cells (24) of the motif image together forming a respective micro-motif element (50) that corresponds to one of the moiré image elements (86) of the magnified moiré image (84) and that is wider than a grid cell (24) of the motif image.
The invention relates to a security element for security papers, documents of value and the like, having a moiré-type micro-optical magnification arrangement for displaying a moiré image with one or more moiré picture elements.
Data carriers, such as valuables or identity documents, but also other valuables, such as branded goods, are often provided with security elements for the purpose of security, which permit verification of the authenticity of the data carrier and at the same time serve as protection against unauthorized reproduction. The security elements can be embodied, for example, in the form of a security thread embedded in a banknote, a covering film for a banknote with a hole, an applied security strip or a self-supporting transfer element which is applied to a value document after its manufacture.
Security elements with optically variable elements, which give the viewer a different image impression under different viewing angles, play a special role, since they can not be reproduced even with high-quality color copying machines. For this purpose, the security elements can be equipped with security features in the form of diffraction-optically effective microstructures or nanostructures, such as with conventional embossed holograms or other hologram-like diffraction structures, as described, for example, in the publications EP 0 330 733 A1 or EP 0 064 067 A1 are described.
It is also known to use lens systems as security features. For example, in the document EP 0 238 043 A2 a security thread of a transparent material described on the surface of a Grid is embossed from several parallel cylindrical lenses. The thickness of the security thread is chosen so that it corresponds approximately to the focal length of the cylindrical lenses. On the opposite surface of a printed image is applied register accurate, the print image is designed taking into account the optical properties of the cylindrical lenses. Due to the focusing effect of the cylindrical lenses and the position of the printed image in the focal plane different subregions of the printed image are visible depending on the viewing angle. By appropriate design of the printed image so that information can be introduced, which are visible only at certain angles. By appropriate design of the printed image while "moving" images can be generated. However, as the document rotates about an axis parallel to the cylindrical lenses, the subject moves only approximately continuously from one location on the security thread to another location.
Based on this, the object of the invention is to avoid the disadvantages of the prior art and, in particular, to provide a security element with a moiré-type micro-optical magnification arrangement, which offers a large margin in the design of the motif images to be viewed.
This object is achieved by the security element having the features of the main claim. A method for producing such a security element, a security paper and a data carrier with such a security element are specified in the independent claims. Further developments of the invention are the subject of the dependent claims.
According to the invention, a generic security element includes a moiré-type micro-optical magnification arrangement
a motif image which contains a periodic or at least locally periodic arrangement of a plurality of grid cells with micromotif image parts,
a spaced apart from the motif image Fokussierelementraster moiré-magnified viewing of the motif image, the one contains periodic or at least locally periodic arrangement of a plurality of grid cells each having a microfocusing element,
wherein the micromotif image portions of a plurality of spaced grid cells of the motif image taken together form a micromotif element corresponding to one of the moire pixels of the magnified moiré image and whose extent is larger than a grid cell of the motif image.
In the context of this application, the term "moiré magnification arrangement" designations in which the micromotif elements are equal to each other, regularly arranged in the form of a grid and fit with their size in a grid cell. The generation of a moiré image from a multiplicity of regularly arranged, identical micromotif elements takes place according to the moire magnification principle described above.
The more general term "moiré-type magnification arrangement" in the context of this application designates embodiments in which the micromotif element to be displayed can also be larger than a grid cell of the motif image. The term "Moire type magnification arrangement" therefore includes the more specific moire magnification arrangements. The expression that the extension of the micromotiv element is larger than a grid cell of the motif image expresses that the micromotif element in its selected or calculated orientation does not fit within a grid cell of the motif image, also in the selected or calculated orientation In the case of a periodic repetition of the micromotif element in the grid cells, overlaps of adjacent micromotif elements generally occur. A micromotif element and a moiré pixel, when directly transposed by the image produced by the magnification arrangement, can include the magnification, rotation, reflection, and shear of the pixel. This mapping can be indicated, for example, by the transformation matrix A of the magnification arrangement described in greater detail below.
While conventional designs are limited to motif images with motif pixels that fit into a grid cell of the motif grid, the measure according to the invention also makes it possible to use moiré-type magnification arrays to represent motif pixels that are larger than a grid cell without overlapping in the moiré image. This gives the designer much greater creative freedom in the design of moiré motifs, since he is no longer strictly bound to the shape and size of the grid cells of the motif grid. Moreover, for a given total thickness of the magnification arrangement, particularly extended moire pixels are made possible in the first place.
On the other hand, by dividing a given motif element into a plurality of grid cells, in particular, particularly thin magnification arrangements can be produced. For technical reasons, the thickness of a moiré magnification arrangement is approximately the same as the screen ruling of the motif grid used. Since in conventional designs the motif elements each have to fit in a grid cell, the thickness of the moiré magnification arrangement can not be smaller than the smallest possible technically realizable motif size. This hurdle is overcome by the inventive division of a given motif element on multiple grid cells.
For example, a motif element of dimension a conventionally requires a grid cell of at least the size a and thus, due to general considerations, also requires a moire magnification array thickness of the order a, for example, in a particular embodiment the thickness may be at least 1.5 * a. The same motif element can be distributed according to the invention at halved screen a / 2 on four grid cells, so that the thickness of the moiré-type magnification arrangement to a value of the order of magnitude a / 2, in the aforementioned embodiment, to a thickness of 1.5 * a / 2 are reduced can. Of course, with a distribution to a larger number of grid cells, the thickness can be reduced even more.
In one variant of the invention, both the grid cells of the motif image and the grid cells of the focusing element grid are arranged periodically. The periodicity length is preferably between 3 μm and 50 μm, preferably between 5 μm and 30 μm, particularly preferably between about 10 μm and about 20 μm.
According to another variant of the invention, both the grid cells of the motif image and the grid cells of the focusing element grid are arranged locally periodically, the local period parameters changing only slowly in relation to the periodicity length. For example, the local period parameters may be periodically modulated over the extent of the security element, wherein the modulation period is preferably at least 20 times, preferably at least 50 times, more preferably at least 100 times greater than the local periodicity length. Also in this variant, the local periodicity length is preferably between 3 μm and 50 μm, preferably between 5 μm and 30 μm, particularly preferably between about 10 μm and about 20 μm.
The grid cells of the motif image and the grid cells of the focusing element grid advantageously form, at least locally, respectively a two-dimensional Bravais grid, preferably a Bravais grid with low symmetry, such as a parallelogram grid. The use of low symmetry Bravais gratings offers the advantage that moiré-type magnification arrangements are difficult to imitate with such Bravais gratings, since to form a correct image when viewed, the low-symmetry of the array, which is difficult to analyze, must be precisely adjusted , In addition, the low symmetry provides a large freedom for differently selected grid parameters, which can thus be used as a hidden marking for products secured according to the invention, without this being readily apparent to a viewer on the moire-enlarged image. On the other hand, any attractive effects achievable with higher-symmetry moiré magnification arrangements can also be realized with the preferred moiré-type low-symmetry magnification arrangements.
The lateral dimensions of the grid cells of the motif image and of the grid cells of the focusing element grid are preferably below about 100 μm, preferably between about 5 μm and about 50 μm, particularly preferably between about 10 μm and about 35 μm.
The microfocusing elements are preferably formed by non-cylindrical microlenses, in particular by microlenses with a circular or polygonal limited base surface. In other configurations, the microfocusing elements can also be formed by elongated cylindrical lenses, whose longitudinal extension is more than 250 μm, preferably more than 300 μm, particularly preferably more than 500 μm and in particular more than 1 mm.
In further preferred embodiments, the microfocusing elements are pinhole apertures, slotted apertures, apertured apertured apertured apertures, aspherical lenses, Fresnel lenses, gradient refraction index (GRIN) lenses, zone plates, holographic lenses, concave mirrors, Fresnel mirrors, zone mirrors, or other focusing or focusing elements also formed with a masking effect.
The total thickness of the security element is advantageously below 50 μm, preferably below 30 μm and particularly preferably below 20 μm. By the division according to the invention even thinner designs are possible with a total thickness of about 10 microns or less, or even with a total thickness of about 5 microns or less.
The micromotif images preferably form micromotif elements in the form of microcharacters or micropatterns and may be present in particular in an embossed or printed layer.
In a second aspect, the invention includes a generic security element having a moiré-type micro-optical magnification arrangement for displaying a moiré image with a plurality of moire pixels
a motif image containing a periodic or at least locally periodic arrangement of a plurality of micromotif element grid cells, each micromotif element corresponding to one of the moire pixels,
wherein the motif image is subdivided into areas each associated with one of the moire pixels and corresponding in position and size to the associated moire pixel, and wherein the micromotifs corresponding to a moire pixel are respectively arranged in the area of the motif image repeating the same Moiré picture element is assigned.
According to an advantageous development of the invention, the security element in both aspects has an opaque covering layer for the area-wise covering of the magnification arrangement of the moire type. Thus, no moire magnification effect occurs within the covered area, so that the optically variable effect can be combined with conventional information or with other effects. This cover layer is advantageously in the form of patterns, characters or codes before and / or has recesses in the form of patterns, characters or codes.
In all of the aforementioned variants of the invention, the motif image and the focusing element grid are preferably arranged on opposite surfaces of an optical spacer layer. The spacer layer may comprise, for example, a plastic film and / or a lacquer layer.
The arrangement of microfocusing elements can moreover be provided with a protective layer whose refractive index preferably deviates by at least 0.3 from the refractive index of the microfocusing elements, if refractive lenses serve as microfocusing elements. In In this case, the focal length of the lenses changes as a result of the protective layer, which must be taken into account when dimensioning the lens radii of curvature and / or the thickness of the spacer layer. In addition to protection against environmental influences, such a protective layer also prevents the microfocusing element arrangement from easily being molded for counterfeiting purposes.
The security element itself in all aspects of the invention preferably represents a security thread, a tear-open thread, a security strip, a security strip, a patch or a label for application to a security paper, value document or the like. In an advantageous embodiment, the security element can form a transparent or recessed area of a data medium span. Different appearances can be realized on different sides of the data carrier.
The invention also includes a method for producing a security element having a moiré-type micro-optical magnification arrangement for displaying a moiré image with one or more moire picture elements, in which
in a motif plane, a motif image is generated with a periodic or at least locally periodic arrangement of a plurality of grid cells with micromotif image parts,
a focusing element grid for moire-magnified viewing of the motif image with a periodic or at least locally periodic arrangement of a plurality of grid cells each having a microfocusing element is generated and arranged at a distance from the motif image,
wherein the micromotif image portions are formed such that the micromotif image portions of a plurality of spaced lattice cells of the motif image collectively form a micromotif element corresponding to one of the moire pixels of the enlarged moiré image and the extent thereof is larger than a lattice cell of the motif image.
To determine such similar motif subsets and the associated focusing element subsets of Fokussierelementrasters, is provided in a preferred embodiment of the method that
a) defining a desired moiré image to be viewed with one or more moiré picture elements as target motif,
b) a periodic or at least locally periodic arrangement of microfocusing elements is determined as focussing element grid,
c) a desired magnification and a desired movement of the moiré image to be seen is determined during lateral tilting and during forward / backward tilting of the magnification arrangement,
d) the micromotif element and the motif grid to be introduced into the motif plane are calculated from the defined magnification and movement behavior, the focusing element grid and the target motif,
e) it is checked whether an arrangement of the micromotif elements repeated with the symmetry of the motif grid leads to overlapping, and if this is the case,
f) similar motif subsets of the micromotif element arrangement produced in step e) are determined, in which the micromotif elements are arranged repeatedly without overlapping,
g) similar focusing element subsets of the focusing element grid corresponding to the motif subsets are determined and associated with the respective motif subset,
h) for each focusing element subset, the intersection of the corresponding focusing element sub-grid with the associated motif subset is determined, and
i) the resulting sections are assembled according to the relative position of the focusing element subset in Fokussierelementraster to be arranged in the motif plane motif image.
It is important that the motif subsets determined in step f) not only have an overlap-free representation of the micromotif elements, but that the determined motif subsets together with the corresponding focusing element subsets of Fokussierelementrasters each form magnification arrangements of moire type, the same target motive to lead. This is expressed by the phrase that the motive subsets determined in step f) should all be "similar."
In a further advantageous development of the method, it is provided that
c) a desired magnification and a desired movement of the moire image to be seen is determined during lateral tilting and during forward / backward tilting of the magnification arrangement,
d) from the defined magnification and movement behavior, the focusing element grid and the target motif, the micromotive element to be introduced into the motif plane and the motif grid are calculated,
f ') a superlattice grid of the motif grid is determined, in which the micromotif elements can be repeatedly arranged without overlapping,
g ') a superlattice grid of the focusing element grid corresponding to the motif superlattice grid is determined and the focusing element grid is decomposed into subgrids with the symmetry of the focusing element superlattice grid,
h ') for each focusing element sub-grid the section of the sub-grid is determined with an overlap-free arrangement of the micromotif elements, and
i ') the resulting sections are assembled according to the relative position of the respective sub-grid in the focusing element superlattice grid to the motif image to be arranged in the motif plane.
A superlattice grid is understood to mean a grid whose unit cell contains a plurality of grid cells of the underlying basic grid. For example, the unit cell of a simple superlattice grid can comprise 2 × 2, 2 × 3 or 3 × 2 grid cells of the basic grid.
Preferably, in this method, after step g ') in one step
g ") for each focussing element sub-grid determines the corresponding motif sub-grid and determines the offset of this motif sub-grid relative to the motif superlattice cell, and in step
h ') for each focusing element sub-grid the overlap-free arrangement of the micromotif elements determined in step f') is shifted by the offset of the associated motif sub-grid determined in step g ") and the section of the focusing element sub-grid determined with the shifted overlap-free arrangement of the micromotif elements.
The focussing element grid is suitably defined in step b) in the form of a two-dimensional Bravais lattice, whose lattice cells are identified by vectors w 1 and w 2 are given. The desired enlargement and movement behavior in step c) is advantageously in the form of the matrix elements of a transformation matrix A specified. The micromotif element and the motif grid to be introduced into the motif plane then become advantageous in step d) using the relationships U → = I → - A → - 1 ⋅ W →
and r → = A → - 1 ⋅ R → + r → 0
calculated, where R → = X Y
a pixel of the desired moiré image, r → = x y
a pixel of the motif image, r → 0 = x 0 y 0
represents a shift between the focus grid and the motif image, and the matrices A . W and the motif grid matrix U by A ↔ = a 11 a 12 a 21 a 22 .
W ↔ = w 11 w 12 w 21 w 22
respectively. U ↔ = u 11 u 12 u 21 u 22
where u 1i , u 2i and w 1i , w 2i are the components of the lattice cell vectors u i and w i , with i = 1.2.
In step f '), preferably a motif superlattice grid is selected, which consists of n × m grid cells of the motif grid, wherein for n and m preferably the smallest values are selected, which are an overlap-free arrangement allow the micromotif elements. The focusing element grid is preferably decomposed in nxm sub-grid in step g ').
Advantageously, the motif grid is decomposed into nxm motif sub-grid in step g "), and for each motif sub-grid the offset based on the motif super-grid cell is determined v j with j = 1, ... n * m, of the motif subgrid.
Furthermore, with advantage in step h ') for each focusing element sub-grid, the overlap-free arrangement of the micromotif elements determined in step f') is offset by the offset v j of the associated motif sub-grid shifted and determines the section of the focusing element sub-grid with the shifted overlap-free arrangement of the micromotif elements.
According to the second aspect of the invention, the invention also includes a method for producing a security element having a moiré-type micro-optical magnification arrangement for displaying a moire image with a plurality of moire picture elements, in which
a motif image is generated with a periodic or at least locally periodic arrangement of a plurality of grid cells with micromotif elements, each micromotif element corresponding to one of the moiré image elements,
a focusing element grid for moire-magnified viewing of the motif image is generated with a periodic or at least locally periodic arrangement of a plurality of grid cells, each with a microfocusing element and spaced from the motif image,
wherein the motif image is divided into areas each associated with one of the moire pixels and corresponding in position and size to the associated moiré pixel, and wherein the micromotifs corresponding to a moiré pixel are respectively repeated in the area of the motif image Moire picture element is assigned.
In both aspects of the invention, the lattice parameters of the Bravais lattices may be location independent. However, it is also possible to use the lattice vectors of the motif grid and focussing grid, u 1 and u 2 , or w 1 and w 2 to be spatially dependent, where the local period parameters | u 1 |, | u 2 |, ∠ ( u 1 , u 2 ) or | w 1 |, | w 2 |, ∠ ( w 1 , w 2 ) according to the invention change only slowly in relation to the periodicity length. This ensures that the arrangements can always be meaningfully described locally by means of Bravais grids.
The invention also includes a data carrier, in particular a brand article, a document of value, a decorative article, such as packaging, postcards or the like, with a security element of the type described above. The security element can in particular in a window area, ie a transparent or recessed area of Be arranged data carrier.
schematically the conditions when considering a magnification arrangement of the moire type to define the occurring sizes,
in (a) a predetermined nominal motif in the form of the letter "P", and in (b) a predetermined lens array with a square lenticular grid,
in (a) the calculated micromotif element repeatedly to be introduced into the motif grid, the motif grid and a part of the lenticular grid, and in (b) the conventionally repeatedly arranged overlapping micromotif elements,
in (a) a motif superlattice grid whose grid cells each consist of 2 × 2 grid cells of the dashed-off motif grid and in (b) the motif superlattice grid, the dashed motif grid and four similar, non-overlapping motif subsets in detail,
in (a) the non-overlapping arrangement of the micromotif elements of Fig. 6 (a) together with a lens grid pattern corresponding to the motif superlattice grid, and in (b) the lens superlattice grid and the lenticular grid shown in dashed lines in detail,
in (a) to (d) in each case a non-overlapping arrangement of the micromotif elements (gray), a sub-grid of the lenticular grid as well as the cut out of this sub-grid with the motif element arrangement motif image parts (black), in (e) to a motif image composite sectional images from the steps (a) to (d), and in (f) when viewing the motif image (e) with the lens array of Fig. 4 (b) resulting enlarged moiré image,
for a further embodiment, a non-overlapping array of micromotif elements within a motif superlattice consisting of 2 x 2 lattice cells,
a sub-grid of the lenticular grid with the symmetry of the motif grid of the grid Fig. 9 corresponding lens grid,
the finished motif image, composed of the four sectional images of the four lens sub-grids with suitably shifted overlap-free arrangements of the micromotif elements,
when looking at the subject image of the Fig. 11 with the lens array of Fig. 4 (b) resulting enlarged moiré image,
in (a) a motif layer composed of motifs "A", "B", "C" which, combined with the appropriate lenticular grid, gives the enlarged moiré image shown in (b),
a representation like Fig. 13 for an embodiment in which the letter motifs "A", "B", "C" move in different directions when tilting the moiré-type magnification arrangement, and
an embodiment with a long motif element "B", wherein (a) shows the distorted motif element together with the lenticular grid, (b) the motif image and (c) shows the resulting moiré image in a conventional procedure, and (d) and (e) show the motif image or the moiré image in accordance with the invention.
The invention will now be explained using the example of a security element for a banknote. Fig. 1 shows a schematic representation of a banknote 10, which is provided with two security elements 12 and 16 according to embodiments of the invention. The first security element represents a security thread 12 that emerges in certain window areas 14 on the surface of the banknote 10, while it is in between lying areas inside the banknote 10 is embedded. The second security element is formed by a glued transfer element 16 of any shape. The security element 16 can also be designed in the form of a cover film, which is arranged over a window area or a through opening of the banknote. The security element may be designed for viewing in supervision, review or viewing both in supervision and in review. Bilateral designs are also possible in which lenticular screens are arranged on both sides of a motif image.
Both the security thread 12 and the transfer element 16 may include a moiré type magnification assembly according to an embodiment of the invention. The mode of operation and the production method according to the invention for such arrangements will be described in more detail below with reference to the transfer element 16.
Fig. 2 shows schematically the layer structure of the transfer element 16 in cross section, wherein only the parts of the layer structure required for the explanation of the principle of operation are shown. The transfer element 16 includes a carrier 20 in the form of a transparent plastic film, in the embodiment of an approximately 20 micron thick polyethylene terephthalate (PET) film.
The upper side of the carrier film 20 is provided with a grid-like arrangement of microlenses 22 which form on the surface of the carrier film a two-dimensional Bravais grid with a preselected symmetry. The Bravais lattice may, for example, have a hexagonal lattice symmetry, but because of the higher security against forgery, preferred are lower symmetries and thus more general shapes, in particular the symmetry of a parallelogram lattice.
The spacing of adjacent microlenses 22 is preferably chosen as small as possible in order to ensure the highest possible area coverage and thus a high-contrast representation. The spherically or aspherically configured microlenses 22 preferably have a diameter between 5 μm and 50 μm and in particular a diameter between only 10 μm and 35 μm and are therefore not visible to the naked eye. It is understood that in other designs, larger or smaller dimensions come into question. For example, in the case of moiré magnifier structures, the microlenses can have a diameter of between 50 μm and 5 mm for decorative purposes, while moire magnifier structures which can only be deciphered with a magnifying glass or a microscope also use dimensions of less than 5 μm can come.
A motif layer 26 is arranged on the underside of the carrier film 20, which also has a grid-like arrangement of a plurality of grid cells 24 with different micromotif image parts 28, 28 ', 28 ". As explained in more detail below, the micromotif image parts of a plurality of spaced grid cells 24 form the motif layer 26 each a micromotif element that corresponds to one of the moire pixels of the enlarged moiré image and whose extent is greater than a grid cell 24.
The arrangement of the grid cells 24 also forms a two-dimensional Bravais grid with a preselected symmetry, again assuming a parallelogram grid for illustration. As in Fig. 2 indicated by the offset of the grid cells 24 relative to the microlenses 22, the Bravais grid of the grid cells 24 differs slightly in its symmetry and / or in the size of its grid parameters from the Bravais grid the microlenses 22 to produce the desired moiré magnifying effect. The grating period and the diameter of the grid cells 24 are of the same order of magnitude as those of the microlenses 22, that is to say preferably in the range of 5 μm to 50 μm and in particular in the range of 10 μm to 35 μm, so that the micromotif image parts 28, 28 ', 28 "can not be seen even with the naked eye In designs with the above-mentioned larger or smaller microlenses, it goes without saying that the grid cells 24 are also correspondingly larger or smaller.
The optical thickness of the carrier film 20 and the focal length of the microlenses 22 are coordinated so that the motif layer 26 is located approximately at a distance of the lens focal length. The carrier film 20 thus forms an optical spacer layer, which ensures a desired, constant spacing of the microlenses 22 and the motif layer with the micromotif image parts 28, 28 ', 28 ".
Due to the slightly different lattice parameters, when viewed from above through the microlenses 22, the observer sees a slightly different subarea of the micromotif images 28, 28 ', 28 "so that the plurality of microlenses 22 collectively form an enlarged image of the micromotif elements formed from the micromotif images The resulting moiré magnification depends on the relative difference of the lattice parameters of the Bravais lattices used, for example, if the lattice periods of two hexagonal lattices differ by 1%, the result is a 100-fold moiré magnification the operation and advantageous arrangements of the motif grid and the microlens grid is based on the German patent application 10 2005 062132.5 and the international application PCT / EP2006 / 012374 referenced, the disclosure of which is included in the present application in this respect.
The peculiarity of the present invention consists in the fact that the micromotif elements of the motif layer 26, which correspond to the moire picture elements of the enlarged moire image, are larger than the extent of a grid cell 24 of the motif layer 26 and therefore are not simply periodically repeated due to the occurring overlaps the motif layer can be arranged. Rather, the micromotif elements according to the invention are decomposed in a suitable manner into micromotif image parts, which are each housed within one of a plurality of spaced grid cells 24 and which together form the respective micromotif element. The division of a micromotif element into micromotif image parts and the distribution of the image parts on grid cells must be done according to certain rules, if the image parts to the viewer correctly and consistently to be assembled into a high-contrast, enlarged moire pixel.
With the described division of larger motifs according to the invention, it is possible in particular to produce particularly thin moiré magnifiers. For technical reasons, the thickness of a moiré magnifier arrangement is approximately equal to the screen ruling of the motif grid. Since, according to the prior art, the motifs each have to fit into a motif grid cell, the thickness can conventionally not be made smaller than the smallest possible technically realizable motif size. This hurdle is overcome according to the invention by extending the motif over several grid cells.
For example, in the prior art, there is a method of producing just 10 μm large motifs suitable for moiré magnifiers for smaller ones Motifs, the resolution of the method is not enough. Such a 10μm motif just fits in a 10μm raster, so that conventionally with this method you can not produce moiré magnifiers that are thinner than 10 μm. According to the invention, however, it is possible to accommodate a 10 μm motif in four grid cells of a 5 μm grid and thus to produce a 5 μm thin moiré magnifier. Of course, one can accommodate the 10 .mu.m motif according to the method of the invention divided into more than four grid cells and produce in this way virtually arbitrarily thin Moiré Magnifier.
To explain the procedure according to the invention, reference will first be made to FIG Fig. 3 the required sizes are defined and briefly described. For a more detailed representation is in addition to the aforementioned German patent application 10 2005 062132.5 and the international application PCT / EP2006 / 012374 referenced, the disclosure of which is included in the present application in this respect.
Fig. 3 schematically shows a magnification arrangement of the moire type 30 not shown to scale with a motif plane 32 in which the motif image is arranged with the micromotif image parts, and with a lens plane 34 in which the microlens grid is located. The moiré-type magnification device 30 generates a moire image plane 36 which describes the magnified moiré image perceived by the viewer 38.
The arrangement of the micromotif image parts in the motif plane 32 is described by a two-dimensional Bravais lattice whose unit cell is represented by vectors u 1 and u 2 (with the components u 11 , u 21 and u 12 , u 22 ) can be represented. In compact notation, the unit cell also in matrix form by a motif grid matrix U (hereinafter often simply called motif grid): U ↔ = u ~ 1 u ~ 2 = u 11 u 12 u 21 u 22 ,
In the same way, the arrangement of microlenses in the lens plane 34 is described by a two-dimensional Bravais lattice whose unit cell is represented by the vectors w 1 and w 2 (with the components w 11 , w 21 and w 12 w 22 ) is given. With the vectors t 1 and t 2 (with the components t 11 t 21 and t 12 , t 22 ), the unit cell in the moire image plane 36 is described.
With r → = x y
is a general point designated as the motif plane 32, with R → = X Y
a general point of the moiré image plane 36. In addition to vertical viewing (viewing direction 35) to be able to describe non-perpendicular viewing directions of the magnification moire type, such as the general direction 35 ', an additional shift between the lens plane 34 and 32 Motivebene allowed by a displacement vector r → 0 = x 0 y 0
is indicated in the motif level 32. Analogous to the motif grid matrix, the matrices are used to compactly describe the lens raster and the image raster W ↔ = w 11 w 12 w 21 w 22
(called lenticular matrix or simply lenticular grid) and T ↔ = t 11 t 12 t 21 t 22
In the lens plane 34, instead of lenses 22, it is also possible, for example, to use pinholes on the principle of the pinhole camera. Also all other types of lenses and imaging systems, such as aspheric lenses, cylindrical lenses, slit diaphragms, apertured apertured or slit diaphragms, Fresnel lenses, GRIN (Gradient Refraction Index) lenses, zoned diffraction lenses, holographic lenses, concave mirrors, Fresnel mirrors, zone mirrors and other elements with focussing or also ausblendender effect can be used as Mikrofokussierelemente in Fokussierelementraster.
In principle, in addition to elements with focussing effect elements with ausblendender effect (hole or slit, even mirror surfaces behind hole or slit) can be used as Mikrofokussierelemente in Fokussierelementraster.
When using a concave mirror array and in other inventively used reflective focusing grids the viewer looks through the partially transparent in this case motif image on the mirror array behind it and sees the individual small mirror as light or dark points from which builds the image to be displayed. The motif image is generally so finely structured that it can only be seen as a veil. The described formulas for the relationships between the moiré image to be displayed and the motif image apply, even if this is not mentioned in detail, not only for lenticular raster but also for mirror raster. It is understood that in the inventive use of concave mirrors at the location of the lens focal length, the mirror focal length occurs.
In the inventive application of a mirror array instead of a lens array is in Fig. 2 to think of the viewing direction from below, and in Fig. 3 In the mirror array arrangement, the levels 32 and 34 are interchanged. The further description of the invention is based on lens grids, which are representative of all other inventively used Fokussierelementraster.
The moiré image grid results from the grid vectors of the motif plane 32 and the lens plane 36 too T ↔ = W ↔ ⋅ W ↔ - U ↔ - 1 ⋅ U ↔
and the pixels of the moire image plane 36 can be determined using the relationship R → = W ↔ ⋅ W ↔ - U ↔ - 1 ⋅ r → - r → 0
be determined from the pixels of the motif level 32. Conversely, the grid vectors of the motif plane 32 result from the lenticular grid and the desired moiré image grid U ↔ = W ↔ ⋅ T ↔ - W ↔ - 1 ⋅ T ↔
and r → = W ↔ ⋅ T ↔ + W ↔ - 1 ⋅ R → + r → 0 ,
Define the transformation matrix A = W · ( W - U ) -1 , which converts the coordinates of the points of the motif plane 32 and the points of the moiré image plane 36 into each other, R ↔ = A ↔ ⋅ r → - r → 0 . respectively , r → = A ↔ - 1 ⋅ R → + r → 0 .
so can each have two of the four matrices U . W . T . A the other two are calculated. In particular: T → = A ↔ ⋅ U ↔ = W ↔ ⋅ W ↔ - U ↔ - 1 ⋅ U ↔ = A ↔ - I ↔ ⋅ W ↔
U → = W ↔ ⋅ T ↔ + W ↔ - 1 ⋅ T ↔ = A ↔ - 1 ⋅ T ↔ = I ↔ ⋅ A ↔ - 1 ⋅ W ↔
W ↔ = U ↔ ⋅ T ↔ - U ↔ - 1 ⋅ T ↔ = A ↔ - I ↔ - 1 ⋅ T ↔ = A ↔ ⋅ I ↔ - 1 ⋅ A ↔ ⋅ U ↔
A ↔ = W ↔ ⋅ W ↔ - U ↔ - 1 = T ↔ + W ↔ ⋅ W ↔ - 1 = T ↔ ⋅ U ↔ - 1
in which I denotes the unit matrix.
As in the referenced German patent application 10 2005 062132.5 and the international application PCT / EP2006 / 012374 described in detail, describes the transformation matrix A both the moire magnification and the resulting movement of the magnified moiré image upon movement of the moiré-forming assembly 30 resulting from the displacement of the motif plane 32 against the lens plane 34.
The raster matrices T, U, W, the unit matrix I and the transformation matrix A are often subsequently also written without a double arrow, if it is clear from the context that these are matrices.
In the design of moiré-type magnification assemblies, one generally assumes an increased moiré image than the target subject to be viewed, the desired magnification factor, and the desired moiré image movement behavior for sideways and forward / backward tilting of the assembly. The desired magnification and movement behavior of the target motif may be in the transformation matrix A be summarized.
The arrangement of the microlenses can, as in the present example, on the lenticular grid matrix W be specified. Alternatively, only certain restrictions or conditions may be imposed on the lens assembly and the required lens arrangement calculated along with the motif image.
For illustration shows Fig. 4 (a) a predetermined target motif 40, here in the form of the letter "P" and Fig. 4 (b) a predetermined lens array with spherical microlenses 46, which are arranged in a simple square grid, the lenticular grid 42 with square grid cells 44.
The magnification and movement behavior is in the embodiment in the form of the transformation matrix A = 7 0 0 7
given, which describes a pure magnification by a factor of 7. It should be emphasized at this point that to illustrate the principle of the invention intentionally simple embodiments are described, which can be represented well and approximately true to scale in the drawing. For this purpose, simple and highly symmetrical grid arrangements and simple transformation matrices are selected in this and in the following examples.
From the above specifications, one obtains the micromotiv to be introduced into the motif plane in the manner described above by using the reversal matrix A -1 to the target motif. Also the motif grid U , in which the micromotif elements must be arranged, is determined by the specifications made and is given by relationship (M2) by U ↔ = I ↔ - A ↔ - 1 ⋅ W ↔ ,
Fig. 5 (a) shows the thus calculated to be introduced micromotive element 50 and the motif grid 52, which also represents a simple square grid in the selected specifications. In addition, a portion of the lens grid 42 is shown with dashed lines. As in Fig. 5 (a) to recognize is the periodicity length Lu of the motif grid 52 is slightly smaller than the periodicity length Lw of the lens grid 42, namely L U = 6 / 7 * L W .
as can be seen from the relationships (B1-1) and (B1-2).
As in Fig. 5 (a) If the micromotif element 50 is therefore periodically repeated in the motif grid 52 in a conventional manner, the micromotive element 50 to be introduced is larger than a grid cell 54 of the motif grid 52 Fig. 5 (b) shown motif image 56, which has strong overlaps of the individual motif elements 50. If the subject image 56 with the lens array of Fig. 4 (b) Also, the resulting enlarged moiré image shows corresponding unwanted overlaps of the enlarged letter "P", and the target motif 40 is not recognizable as such in the moiré image.
In order to eliminate these overlaps and to enable the representation of a gapless, high-contrast moiré image with non-overlapping Moire picture elements, according to the invention similar motif subsets of the micromotif element arrangement 66 of FIG Fig. 5 (b) determined in which the micromotif elements 50 are arranged repeatedly without overlap. Similar lens subsets of the lens grid 42 corresponding to the motif subsets are then determined for these motif subsets and assigned to the respective subset of motifs. For each lens subset, the intersection of the lens sub-grid corresponding to this subset is then determined with the associated motif subset, and finally the resulting sections are assembled according to the relative position of the lens subset in the lens grid 42 to the motif image to be arranged in the motif plane.
The fact that the determined motif subsets should all be "identical" meant that the motif subsets, together with the corresponding lens subset of the lens grid 42, each form magnification arrangements of the moiré type, which according to the above relationships between the pixels of the moiré image plane and the pixels of the motif layer R → = W ↔ ⋅ W ↔ - U ↔ - 1 ⋅ r → - r → 0 respectively , R → = A ↔ ⋅ r → - r → 0
lead to the same target motive.
In order to determine such similar subsets of motifs in the specific embodiment, a superlattice grid of the motif grid 52 is first determined, in which the micromotif elements 50 can be arranged without overlaps. A superlattice grid is understood to mean a grid whose unit cell contains a plurality of grid cells of the motif grid.
Fig. 6 shows such a motive superlattice grid 62 with grid cells 64, each consisting of 2 x 2 grid cells 54 of dashed lines motif grid 52 consist. The periodicity length L U 'of the superlattice grid 62 is therefore twice as large in both spatial directions as the periodicity length Lu of the motif grid 52. In particular, the motif grid grid 62 is just selected such that its grid cells 64 are larger than the micromotif element 50 to be repeatedly introduced. The choice of such a superlattice grid is not clear, in the exemplary embodiment, for example, a superlattice grid with 2 × 3, 2 × 3, 3 × 3, or an even greater number of grid cells 54 could have been selected. In order to make optimal use of the space available in the motif image, preferably that motif superlattice grid is used with the smallest unit cell still large enough to fully accommodate a micromotif element 50.
If the micromotiv element 50 is now arranged repeatedly in the motif plane with the periodicity of the motif superlattice grid 62, in the exemplary embodiment thus with the periodicity length L U ' , then after the selection of the superlattice grid 62 no overlaps of the micromotif elements 50 result, as in FIG Fig. 6 (a) shown. The arrangement 66 of the micromotif elements 50 repeated with the periodicity length L U ' Fig. 6 (a) represents only a subset of the total, repeated with the periodicity length L U arrangement 56 of the micromotif elements 50 of Fig. 5 (b) is and in the embodiment because of L U * L U = ¼ L U ' * L U '
only a quarter of the original elements.
Fig. 6 (b) shows a part of the motif superlattice grid 62 and the dashed motif grid 52 again in detail. To the right of the two selected grid cells 64 of the motif superlattice grid 62 are the grid vectors u 1 and u 2 of the motif grid 52 drawn.
How out Fig. 6 (b) As can be seen, the motif grid 52 can be divided into four sub-grids 52-1, 52-2, 52-3 and 52-4, each containing only a quarter of the original grid cells 54 of the motif grid 52, and each of the symmetry of the motif superlattice grid 62, ie have a periodicity length L U ' . Taken together, the four sub-grids 52-1, 52-2, 52-3 and 52-4 just again the complete motif grid 52. In the exemplary embodiment, the four sub-grids are given by the left upper grid cell 54 of each superlattice cell 64 (sub-grid 52-1) , through each of the right upper grid cell 54 of each superlattice cell 64 (sub-grid 52-2), through which respectively left lower grid cell 54 of each superlattice cell 64 (subgrid 52-3) and through the respective lower right grid cell 54 of each superlattice cell 64 (subgrid 52-4).
With reference to a superlattice cell 64, the four subgrids 52-1, 52-2, 52-3 and 52-4 have an offset which is in each case represented by a subgrid displacement vector v 1 , v 2 , v 3 and v 4 (FIG. Fig. 6 (b) ) is described. The displacement vectors can be determined by the lattice vectors u 1 and u 2 means
v 1 = 0;
v 2 = u 1 ;
v 3 = u 2 ; and
v 4 = u 1 + u 2 ;
Also in Fig. 6 (b) plotted are the four similar motif subsets 66-1, 66-2, 66-3 and 66-4, which result from displacement of the non-overlapping arrangement 66 of the motif elements 50 by the displacement vectors v 1 to v 4 . The construction of the motif subsets ensures that each of the motif subsets contains an overlap-free arrangement of the motif elements 50, that the motif subsets are identical and therefore produce the same desired motif when viewed with the lens array and that the motif subsets are taken together just the full motif element arrangement 56 of the Fig. 5 (b) result.
The superlattice grid 62 of the motif grid 52 corresponds to a superlattice grid 72 of the lens grid 42 via the above-described relationship (M3). In the exemplary embodiment in which each superlattice cell 64 of the motif grid grid 62 consists of 2 × 2 grid cells 54 of the motif grid 52, the lens superlattice grid 72 formed of superlattice cells 74, which also consist of 2 x 2 grid cells 44 of the lenticular grid 42. The periodicity length L W 'of the lens superlattice grid 72 is therefore twice as large in both directions as the periodicity length Lw of the lens grid 42.
This lens superlattice grid 72, which forms the starting point for further action, is in FIG Fig. 7 together with the micromotif elements 50 repeated with the periodicity L U 'of the motif superlattice grid 62.
Analogous to the decomposition of the motif grid 52 of the Fig. 6 (b) can also be the lenticular grid 42 into four sub-grids 42-1, 42-2, 42-3 and 42-4 are decomposed, each containing only a quarter of the original grid cells 44 of the lenticular grid 42 and the symmetry of the lens superlattice grid 72, so a Periodicity length L W ' . This is in the Fig. 7 (b) illustrating the lens superlattice grid 72 and the dashed lenticular grid 42 in detail. Right next to the two selected grid cells 74 of the lens superlattice grid 72 are the grating vectors w 1 and w 2 of the lens grid 42 drawn. How out Fig. 7 (b) As can be seen, the four sub-grids 42-1, 42-2, 42-3 and 42-4 of the lens grid 42 each comprise a quarter of the original grid cells and together form the complete lens grid 42. In the exemplary embodiment, the four sub-grids are each through the left upper grid cell 44 each Übergitterzelle 74 (sub-grid 42-1, see also Fig. 8 (a) ), through each right upper grid cell 44 of each superlattice cell 74 (sub-grid 42-2, see also Fig. 8 (b) ), by the respective lower left grid cell 44 of each superlattice cell 74 (sub-grid 42-3, see also Fig. 8 (c) ) and by the respective lower right grid cell 44 of each superlattice cell 74 (sub-grid 42-4, see also Fig. 8 (d) ).
In order to obtain a complete and overlap-free motif image, as now with reference to FIG Fig. 8 explains, for each of the sub-grids 42-1, 42-2, 42-3 and 42-4 of the lens grid 42, a sectional image with a suitably shifted arrangement 66 of the motif picture elements 50, ie with one of the motif subsets 66-1, 66-2 , 66-3 and 66-4, and the sectional images of the four sub-grids are composed according to their relative position in the lens superlattice grid 72.
First, the first sub-grid 42-1 is selected, as in Fig. 8 (a) shown, and with the Fig. 6 (a) determined arrangement of the motif picture elements 50 cut. The motif picture element arrangement (motif subset) 66-1 before the cut is shown in gray, the cut motif image parts 80-1 black. The unshifted motif picture element arrangement 66-1 corresponds to a displacement of the motif picture element arrangement 66 of FIG Fig. 6 (a) around the subgrid displacement vector v 1 = 0 of the first motif subgrid 52-1.
Then, as in Fig. 8 (b) shown, the second sub-grid 42-2 of the lens grid 42 selected. The motif subgrid 52-2 corresponding to the second lens subgrid 42-2 has, with respect to the superlattice cell 64, a subgrid displacement vector v 2 = u 1 ( Fig. 6 (b) ). The motif picture element arrangement 66 of FIG Fig. 6 (a) is now moved in the motif plane first by this shift vector v 2 and then cut with the second lens sub-grid 42-2. Also in Fig. 8 (b) For example, the shifted motif picture element arrangement (subject subset) 66-2 before the cut is gray, and the cutout motif picture parts 80-2 are shown in black.
This procedure is then repeated with the third sub-grid 42-3 and the fourth sub-grid 42-4, wherein the motif picture element arrangement 66 of the Fig. 6 (a) before the cut in each case by the displacement vector v 3 and v 4 is moved. The sub-grids 42-3 and 42-4, the shifted motif picture element arrays (motif subsets) 66-3 and 66-4, and the cut-out motif picture parts 80-3 and 80-4, respectively, are in the FIGS. 8 (c) and 8 (d) shown. By the described repeated displacement of the motif picture element arrangement 66 for the different sub-grids respectively disjoint subsets of the Fig. 5 (b) shown complete arrangement 56 of the micromotif elements 50 detected and taken into account all micromotif elements 50.
It is understood that in another choice of the superlattice, a different number and arrangement of sub-grid may arise. For example, in the case of a lens and motif superlattice comprising 2 × 3 grid cells, there are in each case 6 sub-grids whose offset can be expressed in each case by sub-grid shift vectors v 1 through v 6 . Accordingly, then 6 sections of the sub-grid are generated with the corresponding shifted motif picture element arrangements.
Finally, the four sectional images 80-1, 80-2, 80-3 and 80-4 are composed according to the relative position of the sub-grids 42-1, 42-2, 42-3 and 42-4, so that the in Fig. 8 (e) illustrated finished motif image 82 results. For clarity, the lens superlattice grid 72 is indicated by dotted lines.
Will this motif image 82 now with the lens array of Fig. 4 (b) considered, this results in Fig. 8 (f) shown enlarged moire image 84, which shows the desired, non-overlapping and according to the predetermined transformation matrix 7 times enlarged moire pixels 86.
Example 2 is similar to Example 1 of the in Fig. 4 (a) predetermined target motif 40 in the form of the letter "P" and the in Fig. 4 (b) predetermined lens array with square lenticular grid 42 off. It is understood that instead of the letter "P" shown here in the example, also alphanumeric character strings, whole texts or other larger motifs can be treated in the same way. Thus, according to this method, a longer word which does not fit under a lens in the lens array of a moiré magnifier can also be magnified according to the moire magnifier magnification principle according to the invention.
The magnification and motion behavior in Example 2 is through the transformation matrix A = 1 2 ⁢ sin 4 ⁢ ° ⁢ cos 86 ⁢ ° - sin 86 ⁢ ° sin 86 ⁢ ° cos 86 ⁢ °
given, in addition to a magnification and an approximately orthoparallaktischer motion effect is described.
As in Example 1, the micromotive element to be introduced into the motif plane and the motif grid U are first obtained from the transformation matrix A and the lenticular matrix W by means of the reversal matrix A -1 .
Also in example 2, the selected specifications lead to a micromotif element 90 (FIG. Fig. 9 ) which is larger than the dimension Lu of a grid cell of the motif grid U. A conventional repeated arrangement of the micromotif elements 90 at a distance Lu therefore leads to overlaps of the micromotif elements in the motif image and thus also to unwanted overlaps in the enlarged moiré image.
To eliminate these overlaps and to display a gapless, high-contrast moiré image with non-overlapping moire pixels, a superlattice grid of the motif grid U is determined, in which the micromotif elements 90 can be arranged without overlapping. Fig. 9 shows such a non-overlapping array 92 of micromotif elements 90 within a motif superlattice consisting of 2 x 2 motif grid cells.
Then the motif grid is divided into four sub-grids and determines the sub-grid shift vectors v j (j = 1 ... 4) for the offset of the respective sub-grid.
Further, the motif superlattice grid corresponding lens superlattice grid is determined and divided into four sub-grids. One of these four sub-grids 94-j together with the periodicity length L W 'of the lens superlattice grid and the periodicity length Lw of the lenticular grid in FIG Fig. 10 shown.
Now, analogous to the at Fig. 8 For each of the lens sub-grids 94-j, the associated subject sub-grid and its sub-grid shift vector v j determines the overlap-free array 92 of the motif pixels 90 shifted by this sub-grid shift vector v j and the lens sub-grid 94-j brought to the cut. The resulting four sectional images are then assembled according to the position of the lens sub-grids 94-j in the lens superlattice grid, as in FIG Fig. 11 shown, and form the finished motif image 95.
Will this motif picture 95 now with the lens array of Fig. 4 (b) considered, this results in Fig. 12 shown magnified moiré image 96, which shows the desired, non-overlapping and according to the predetermined transformation matrix enlarged moire pixels 98.
With the magnification and movement matrix A used in example 2, an approximately orthoparallactic movement effect is achieved: in the case of lateral tilting of the moire arrangement consisting of the motif image 95 of FIG Fig. 11 and lenticular of the Fig. 4 (b) moves the enlarged moiré image 96 of the Fig. 12 approximately in the vertical direction, when tilted vertically, it moves laterally to the right or left.
Example 3 illustrates an alternative and particularly simple method of accommodating large image motifs in a moire magnifier arrangement. For example, an entire alphabet can be accommodated in a Moiré Magnifier, the procedure for the first letters of the alphabet using Fig. 13 is explained.
Fig. 13 (a) shows a motif layer 100 composed of motifs "A", "B", "C" which combines with the appropriate lenticular grid the magnified moire image 108 of FIG Fig. 13 (b) results. For this purpose, the micromotif elements 102-A, 102-B, 102-C for each letter to be displayed are accommodated in a patch 104-A, 104-B, 104-C of the motif layer 100 of the moiré magnifier, which is just large enough to the moire magnified letters 106-A, 106-B, 106-C of the moiré image 108. The at Moire Magnifier conventionally occurring repetition of the motif is thus suppressed according to the invention here.
With reference to the in Fig. 14 Illustrated example 4 may include the letters "A" (206-A), "B" (206-B), "C" (206-C), and any other components of the present invention Fig. 14 (b) Moire image 208 shown when tilting also move in different ways. For example, the letters 206-A, 206-B, 206-C ... are to move alternately up and down when tilting sideways, but to move rectilinearly when tilted vertically.
Let a be the lens pitch in the hexagonal lenticular grid Fig. 14 (b) designated. The lenticular array of the Fig. 14 (b) is then described by the matrix W = 0 / 2 a a / 2 a ⁢ 3 ,
If m is the desired moire magnification factor, then a vertical movement in the moiré image during lateral tilting is described by the motion matrix A 1 = m ⋅ 0 1 1 0 ,
An opposite vertical movement in the image during lateral tilting while maintaining the direction of movement during vertical tilting is described by the movement matrix A 2 = m ⋅ 0 1 - 1 0
For the motif arrangements for the motif letters "A" (202-A) and "C" (202-C) in the fields 204-A and 204-C of the motif layer 200 ( Fig. 14 (a) ) we choose the raster matrix U 1 = I - A 1 - 1 ⋅ W = 1 - / m 1 - / m 1 1 ⋅ 0 / 2 a a / 2 a ⁢ 3 = - / m a / 2 a - a / 2 ⁢ m 3 a - / 2 ⁢ m a + / 2 a ⁢ 3 ,
For the motif arrangement for the motif letter "B" (202-B) in the field 204-B of the Fig. 14 (a) we choose U 2 = I - A 2 - 1 ⋅ W = 1 / m 1 - / m 1 1 ⋅ 0 / 2 a a / 2 a ⁢ 3 = / m a / 2 a + a / 2 ⁢ m 3 a - / 2 ⁢ m a + / 2 a ⁢ 3 ,
In the case of the grid arrangements selected in this way, the letters "A" (206-A) and "C" (206-C) move in the tilt direction 210 (right up, left down) in the case of tilting in the direction selected Fig. 14 (b) up (direction 212), the letter "B" (206-B) in FIG Fig. 14 (b) down (direction 214). When tilting vertically (front to top), all letters move to the right, when tilting back to the left.
If the letters are to move in opposite directions when tilted vertically, the following motion matrix is used. A special effect in such counter-rotating movements is that the letters merge only in certain tilt directions to a well recognizable sequence (eg a word, in the embodiment "ABC"). A 2 = m ⋅ 0 1 1 0
U 2 = I - A 2 - 1 ⋅ W = 1 / m 1 / m 1 1 ⋅ 0 / 2 a a / 2 a ⁢ 3 = / m a / 2 a + a / 2 ⁢ m 3 a / 2 ⁢ m a + / 2 a ⁢ 3
These movements are only mentioned as examples. Other movements in any direction when tilting can, according to the doctrine of PCT / EP2006 / 012374 be calculated, the disclosure of which is included in the present application in this respect. Also, the direction of movement and / or magnification may change locally, with the range widths and range limits being adjusted accordingly.
As the already mentioned several times and also incorporated herein in this specification application PCT / EP2006 / 012374 As can be seen from the Moire Magnifier, in one direction (eg vertically) infinitely extended motif grid cells with arbitrarily long motifs can be used. In other directions (eg laterally) the grid cell size is limited. Here can - as in PCT / EP2006 / 012374 explained - either cylindrical lenses or two-dimensional lens arrays are applied.
If a larger motif with a 1: 1 image is present in one direction, the procedure of Example 1 can be used as modified. A concrete example shows Fig. 15 , A distorted motif 250 (letter "B") is to be imaged 1: 1 in height, enlarged in width and displayed in an equalized manner. In width, the motif extends across the width of two lenses 252 in the lenticular array, see Fig. 15 (a) , This results in an inventive overlapping motif element arrangement without inventive procedure 254, like Fig. 15 (b) and, correspondingly, an overlapping Moire image 256 as well Fig. 15 (c) shown. In a procedure according to the invention analogous to Example 1, the instead obtained in Fig. 15 (d) illustrated motif image 264 and a proper moiré image 266 with non-overlapping moire pixels 268, such as Fig. 15 (e) shown.
For examples 1 to 5, deliberately simple examples were chosen for illustration, which can be drawn well and approximately to scale. Simple, very symmetrical grid arrangements W (hexagonal or square) were chosen, and simple magnification and movement matrices A (only magnification or rotation with rotation). Of course, for the matrix W, the invention encompasses all two-dimensional Bravais lattices, in particular also those of low symmetry and for A all two-dimensional matrices, ie all products of magnification, reflection, rotation and shear, as for example in the document PCT / EP2006 / 012374 explained in detail, which is incorporated in this regard and in full in the present application.
A security element for security papers, value documents and the like, having a microoptical moire-type magnification arrangement for the non-overlapping depiction of a specified moire image having one or more moire image elements, having
- a motif image that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells having micromotif image portions,
- for the moire-magnified viewing of the motif image, a focusing element grid that is arranged spaced apart from the motif image and that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells having one microfocusing element each,
wherein, taken together, the micromotif image portions of multiple spaced-apart lattice cells of the motif image each form one micromotif element that corresponds to one of the moire image elements of the magnified moiré image and wherein the dimension of the micromotif element is larger than one lattice cell of the motif image.
The security element according to claim 1, characterized in that both the lattice cells of the motif image and the lattice cells of the focusing element grid are arranged periodically, or that, locally, both the lattice cells of the motif image and the lattice cells of the focusing element grid are arranged periodically, the local period parameters changing only slowly in relation to the periodicity length.
The security element according to claim 1 or 2, characterized in that the lattice cells of the motif image and the lattice cells of the focusing element grid form, at least locally, one two-dimensional Bravais lattice each, and/ or that the lateral dimensions of the lattice cells of the motif image and/ or of the lattice cells of the focusing element grid are below about 100 µm, preferably between about 5 µm and about 50 µm, particularly preferably between about 10 µm and about 35 µm.
The security element according to at least one of claims 1 to 3, characterized in that the microfocusing elements are formed by non-cylindrical microlenses or concave microreflectors, especially by microlenses or concave microreflectors having a circular or polygonally delimited base area, or that the microfocusing elements are formed by elongated cylindrical lenses or concave cylindrical reflectors whose dimension in the longitudinal direction measures more than 250 µm, preferably more than 300 µm, particularly preferably more than 500 µm and especially more than 1 mm.
A security element for security papers, value documents and the like, having a microoptical moire-type magnification arrangement for the non-overlapping depiction of a specified moire image having multiple moire image elements, having
- a motif image that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells having micromotif elements, each micromotif element corresponding to one of the moire image elements,
wherein the motif image is broken down into areal regions that are each allocated to one of the moire image elements and correspond in position and size to the allocated moire image element, and wherein the micromotif elements corresponding to a moire image element are each arranged repeatedly in the areal region of the motif image that is allocated to this moire image element.
The security element according to at least one of claims 1 to 5, characterized in that the security element exhibits an opaque cover layer to cover the moire-type magnification arrangement in some regions.
A method for manufacturing a security element having a microoptical moire-type magnification arrangement for the non-overlapping depiction of a specified moire image having one or more moire image elements, in which
- a motif image having a periodic or at least locally periodic arrangement of a plurality of lattice cells having micromotif image portions is produced in a motif plane
- a focusing element grid for the moire-magnified viewing of the motif image, having a periodic or at least locally periodic arrangement of a plurality of lattice cells having one microfocusing element each, is produced and arranged spaced apart from the motif image,
wherein, taken together, the micromotif image portions are developed such that the micromotif image portions of multiple spaced-apart lattice cells of the motif image each form one micromotif element that corresponds to one of the moire image elements of the magnified moire image and wherein the dimension of the micromotif element is larger than one lattice cell of the motif image.
a) a desired moire image that is visible when viewed, having one or more moire image elements, is defined as the target motif,
b) a periodic or at least locally periodic arrangement of microfocusing elements is defined as the focusing element grid,
c) a desired magnification and a desired movement of the visible moire image when the magnification arrangement is tilted laterally and when tilted forward/backward is defined,
d) the micromotif element to be introduced into the motif plane and the motif grid is calculated from the defined magnification and movement behavior, the focusing element grid and the target motif,
f) uniform motif subsets of the micromotif element arrangement produced in step e) are identified in which the micromotif elements are arranged repeatedly, free of overlaps,
g) uniform focusing element subsets of the focusing element grid that correspond to the motif subsets are determined and allocated to the respective motif subset,
h) for each focusing element subset, the intersection of the corresponding focusing element subgrid with the associated motif subset is determined, and
i) the resulting intersections are composed, in accordance with the relative position of the focusing element subset in the focusing element grid, to form the motif image to be arranged in the motif plane.
The method according to claim 7 or 8, characterized in that
c) a desired magnification and a desired movement of the visible moiré image when the magnification arrangement is tilted laterally and when tilted forward/backward is defined,
f') a superlattice grid of the motif grid is identified in which the micromotif elements can be arranged repeatedly, free of overlaps,
g') a superlattice grid of the focusing element grid that corresponds to the motif superlattice grid is determined and the focusing element grid is broken down into subgrids having the symmetry of the focusing element superlattice grid,
h') for each focusing element subgrid, the intersection of the subgrid with an overlap-free arrangement of the micromotif elements is determined, and
i') the resulting intersections are composed in accordance with the relative position of the respective subgrid in the focusing element superlattice grid to form the motif image to be arranged in the motif plane.
The method according to claim 9, characterized in that, after step g'), in a step
g") for each focusing element subgrid, the corresponding motif subgrid is identified and the offset of this motif subgrid with respect to the motif superlattice cell is determined, and in step
h') for each focusing element subgrid, the overlap-free arrangement of the micromotif elements identified in step f') is displaced by the offset of the associated motif subgrid determined in step g"), and the intersection of the focusing element subgrid with the displaced overlap-free arrangement of the micromotif elements is determined.
The method according to at least one of claims 8 to 10, characterized in that the focusing element grid in step b) is defined in the form of a two-dimensional Bravais lattice whose lattice cells are given by vectors w 1 and w 2.
The method according to claim 11, characterized in that the desired magnification and movement behavior in step c) is specified in the form of the matrix elements of a transformation matrix A .
The method according to claim 12, characterized in that, in step d), the micromotif element to be introduced into the motif plane and the motif grid are calculated using the relationships U ↔ = I ↔ - A ↔ - 1 ⋅ W ↔
and r → = A ↔ - 1 ⋅ R → + r → 0
R → = X Y
representing an image point of the desired moire image, r → = x y
an image point of the motif image, r → 0 = x 0 y 0
a displacement between the focusing element grid and the motif image, and the matrices A , W and the motif grating matrix U being given by A ↔ = a 11 a 12 a 21 a 22 , W ↔ = w 11 w 12 w 21 w 22
and U ↔ = u 11 u 12 u 21 u 22 ,
with u1i, u2i and w1i, w2i representing the components of the lattice cell vectors u i and w i, where i=1,2.
The method according to at least one of claims 9 to 13, characterized in that, in step f'), a motif superlattice grid is selected that consists of n x m lattice cells of the motif grid, wherein, for n and m, preferably the smallest values are chosen that permit an overlap-free arrangement of the micromotif elements.
The method according to claim 14, characterized in that, in step g'), the focusing element grid is broken down into n x m subgrids.
The method according to claim 10 and claim 15, characterized in that, in step g"), the motif grid is broken down into n x m motif subgrids and, for each motif subgrid, the offset v j of the motif subgrid with respect to the motif superlattice cell is determined, where j =1, ... n*m, especially that in step h'), for each focusing element subgrid, the overlap-free arrangement of the micromotif elements identified in step f') is displaced by the offset v j of the associated motif subgrid, and the intersection of the focusing element subgrid with the displaced overlap-free arrangement of the micromotif elements is determined.
A method for manufacturing a security element having a microoptical moire-type magnification arrangement for the non-overlapping depiction of a specified moire image having multiple moire image elements, in which
- a motif image having a periodic or at least locally periodic arrangement of a plurality of lattice cells having micromotif elements is produced, each micromotif element corresponding to one of the moire image elements,
wherein the motif image is broken down into areal regions that are each allocated to one of the moiré image elements and correspond in position and size to the allocated moire image element, and wherein the micromotif elements corresponding to a moire image element are each arranged repeatedly in the areal region of the motif image that is allocated to this moire image element.
The method according to at least one of claims 8 to 17, characterized in that the motif grid lattice cells and the focusing element grid lattice cells are described by vectors u 1 and u 2 or w 1 and w 2, and these are modulated location dependently, the local period parameters | u 1|,| u 2|, ∠( u 1 , u 2) and | w 1|,| w 2|, ∠( w 1 , w 2) changing only slowly in relation to the periodicity length.
The method according to at least one of claims 7 to 18, characterized in that the motif image is printed on a substrate, the micromotif elements formed from the micromotif image portions constituting microcharacters or micropatterns.
A security paper for manufacturing security or value documents, such as banknotes, checks, identification cards, certificates or the like, that are furnished with a security element according to at least one of claims 1 to 19, wherein the security paper especially comprises a carrier substrate composed of paper or plastic.
A data carrier, especially a branded article, value document, decorative article or the like, having a security element according to one of claims 1 to 19, wherein the security element is especially arranged in a window region of the data carrier.
EP08784548A 2007-06-25 2008-06-25 Security element Active EP2162294B1 (en)
PCT/EP2008/005173 WO2009000529A2 (en) 2007-06-25 2008-06-25 Security element
EP2162294A2 EP2162294A2 (en) 2010-03-17
EP2162294B1 true EP2162294B1 (en) 2012-03-21
EP (2) EP2162294B1 (en)
CN (2) CN101687428B (en)
RU (2) RU2466028C2 (en)
WO2013048875A1 (en) 2011-09-26 2013-04-04 Technical Graphics, Inc. Method for producing a composite web and security devices prepared from the composite web
WO2016073201A1 (en) * 2014-11-04 2016-05-12 Lumenco, Llc Flat concave micro lens for security as an integrated focusing element
US10215992B2 (en) * 2010-08-23 2019-02-26 Ccl Secure Pty Ltd Multichannel optically variable device
CA2838965A1 (en) 2011-06-28 2013-01-03 Visual Physics, Llc Low curl or curl free optical film-to-paper laminate
MX348573B (en) * 2012-04-25 2017-06-20 Visual Physics Llc Security device for projecting a collection of synthetic images.
CN107364252B (en) * 2017-08-26 2019-06-04 上海速元信息技术有限公司 A kind of finance false proof bill
WO1989008166A1 (en) 1988-03-04 1989-09-08 GAO GESELLSCHAFT FÜR AUTOMATION UND ORGANISATION m Security element in the form of a thread or a ribbon for insertion in security documents, and process for producing it
JP2003039583A (en) * 2001-07-27 2003-02-13 Meiwa Gravure Co Ltd Decorative sheet
EP2287011B1 (en) * 2004-04-30 2017-06-28 Giesecke & Devrient GmbH Security element and process for manufacturing it
EP2164712B1 (en) 2016-08-10
EP2400338B1 (en) 2015-12-16 Image presentation and micro-optic security system
EP2335943B1 (en) 2014-08-20 Micro-optic security and image presentation system
EP1407419B1 (en) 2009-04-22 Diffractive optical device and method of manufacture
CN100534807C (en) 2009-09-02 Diffractive security element comprising a half-tone picture
AU2008267366B2 (en) 2013-06-27 Depiction Arrangement
AU2010294467B2 (en) 2014-09-04 Multilayer body
EP1644871B1 (en) 2012-04-11 Optical safety element and system for visualising hidden information
Ref document number: 502008006746
Ipc: B42D0015100000
Ipc: B42D 15/10 20060101AFI20110922BHEP
Ipc: B42D 15/00 20060101ALI20110922BHEP
Ref document number: 550203
Representative=s name: RENTSCH PARTNER AG