CZ2007874A3 - Security element with static identification pattern, particularly for protecting objects and documents - Google Patents

Abstract

In a security element with a static identification pattern, in particular for protecting an object and a document, the identification pattern (2) remains static when rotating the protected object according to an axis (3) perpendicular to the plane of the security element (1), wherein each image point (4) of the observed identification pattern (2) generated by the security element (1) is formed by the original group (5) of the microbode (6), of which at least one or more microbodes (6) of the original group (5) of the microbode (6) contribute to the pixel (4), wherein, while rotating the diffractive element (1) about an axis (3) perpendicular to the plane of the security element (1), said pixel (4) of the identification pattern (2) is in accordance with the relationship .DELTA.x = r · .DELTA..alpha. formed by the rotated group (7) of the microbode (6), wherein at least one or more of the microbode (6) of the rotated group (7) of the microbode is contributing to the viewer's eye with the same information as at least one or more microbodes (6) of the original group (5 ) of a microbode (6). Some micro-points (6) are alternatively formed by a micro-grid diffracting the incident light into a selected direction according to the equation (M). The security element according to this solution is primarily intended to control the origin of the object and the document by visual inspection, where the observed identification pattern remains static when the protected item is being pivoted.

Description

Protective element with a static identification pattern, in particular for the protection of objects and documents

Technical field

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a security device having a static identification pattern, in particular for the protection of objects and documents, which is intended primarily to prevent falsification and alteration and which allows simple user control. , the font or other designation is static while the object is physically rotating, and where the authenticity of the object by means of this security element is thereby shifted from the professional to the lay plane, thereby assisting its mass exploitation by ordinary users.

BACKGROUND OF THE INVENTION

For the purposes of document protection, it is a general effort to choose methods that are not duplicated by conventional printing techniques. Thus, for example, diffractive elements have been employed, in particular kinetic effect types, in which the level of detail of the micromotives and the embodiment do not allow copying. Checking the authenticity of the document is done "integrally", ie by simply checking whether the motif is color and shape identical to the original and whether the kinetic type is also the desired motif dynamic, for example when tilting the security element about an axis lying in the security element plane or perpendicular to the security element.

The general verification of the authenticity of security features can basically be divided into three spheres, where the first is a simple visual lay check, when we see patterns, color spectrum changes, 2D / 3D effects holograms, kinematics, texts, etc., where there is evident difference in common polygraphic, even color copying.

The second level of inspection and verification is the expert examination of individual, more complicated and production-intensive security features, even with simple aids such as magnifying glasses, pocket microscopes or laser readers and other similar devices.

· · • • •

For the third stage of inspection, laboratory and forensic inspection of the elements is required, where knowledge of the individual technological aspects, location of the security features and cryptographic marks is required, for example strong microscopes and other tools and aids are needed for this.

However, it appears that the possibilities of the first type, i.e. lay control, eliminate the largest number of counterfeits, and therefore focusing on this area is very valuable, which has been the object of the present invention. One embodiment of the invention is based on a diffractive principle.

SUMMARY OF THE INVENTION

The aforementioned layman's possibilities address a security element with a static identification pattern, in particular for the protection of objects and documents, wherein the identification pattern remains static when the object is rotated along an axis perpendicular to the plane of the security element according to the invention. the identification pattern generated by the security element consists of the original group of microdots, of which at least one of the original microdots is contributing to the pixel, and when rotating the security element about an axis perpendicular to the security plane, the pixel of the identification pattern is podleχ = r Δα produced by a rotated group of microdots, again at least one or more of the microdots from the rotated array of microdots is contributing the same information as at least one or more of the original microdots. Alternatively, some microdots consist of a micro-grid diffracting incident light into a selected direction according to a grid equation. Alternatively, some microgrids are superimposed on each other in a single surface. Alternatively, some microbodes are formed by a blazed grid allowing the subject to be rotated to a full angle of up to 360 °, and some microbodes are alternatively formed by suitable reflective points with an element inclination angle perpendicular to the median angle of view and viewing angle to rotate the structure to full 360 °. The pixels are alternatively positioned generally in space, and microdots from the plane of the security element from different groups of microdots are simultaneously contributing to the pixel.

· «9 9 I I I I I I I B B B B B

The advantages of the present invention are primarily that it creates a unique, easily identifiable visual effect for the observer based on a sophisticated method of image creation, where each point of the image can be considered a so-called pixel whose size is chosen between observer's subjective resolution similar to printing and its size according to the distance of observation can be in the range of 5 pm - 5 mm. Each pixel corresponds to a particular group of microdots constituting the security element at a given particular position of rotation of the element. When illuminated by white light, one or more microdots from this group emit light of a given color and intensity spatially corresponding to the selected pixel to the viewing direction. Thus, in a static object and element rotation, a given pixel is always represented by a different point of the element - a different group of microdots. Conversely, the point on the element always creates a different point on the object when shooting. The number of microdots corresponding to one pixel is given by the degree of acceptable "tearing of the object" for the observer as the element is rotated. This number is at least equal to the number of different angles of rotation of the element, if, at a defined rotation, more microbots contribute to a given pixel at a time, this number is understandably greater. If Δα is the elementary allowed angle of rotation of the protected object and r the radius with respect to the axis of rotation in the plane perpendicular to the original, then the change in position Δχ of the microdot group corresponding to the selected pixel in the perpendicular direction is given by:

Ax-r./n where r is variable according to the location on the object.

Given the requirement that each group of microdots on the surface of an element of a size corresponding to the pixel size be able to transmit a signal to all desired discrete rotations of the image relative to the element, it is possible to define the necessary number of microdots in that group.

Diffraction gratings can be advantageously used for the particular implementation of the microdot system of the properties described, which allow the color of the defined location on the object to be selected by the dispersion according to the grid equation at a defined illumination angle and viewing angle. When the light falls on a regular diffraction grating with a period úh at an angle θ, the grid equation i d holds for the diffraction angle prvního of the first diffraction order ** • · Φ Φ ** ** ** ** **

Φ · Φ

44 44 «» 44 «* * * * * * * * * sin θ, = sin #. + ~ αι (Μ) where λ is the wavelength of the light used.

In this case, the need to assemble a group of microdots with a total pixel size with the ability to transmit different information in the required number of directions can be solved either by superposition of grids so-called "over each other" within the same area or by discretization into a separate single grid, the total area of such a system corresponding to the desired size given in the particular case by the choice of pixel size. Separate micro-grids differ in spatial frequency and grid orientation and modulation or elemental area according to color, intensity and defined viewing angle requirements. The number of superimposed gratings or the number of microgrids in spatially separated microdots thus solves the required number of point multiplications.

However, the grid may not be the only way to solve the point multiplication. The microdots emitting contributions to individual pixels may consist of elemental mirrors which are differently mirror-angled to the observer, the mirror reflection of the microdots generally being colored; this can be solved by an elemental reflective grid or a colored spot.

The particular choice of microdots implementation is related to the chosen technology. Since the issue of microgrid realization is well mastered in synthetic holography, the solution is similar to the standard production of a synthetic hologram for a resist. However, in a similar way, ie manufacturing into a resist, it is possible to solve the production of mirror profiles, but the manufacturing of the profile is more complicated, but may resemble the technology of blazed grids. In both cases, a resist pattern is produced in this way and further technological process is given by the known method of mass production of holograms, for example by galvanoplasty, recombination, foil pressing and the like.

A significant advantage of the chosen solution according to the invention is that the respective pixel does not have to belong to a point in the plane of the security element, but can be defined transformed - eg into a 3D object or two dimensional object lying in a plane outside the security element and corresponds to a synthetic 3D or 2D / 3D hologram.

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BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described with reference to the accompanying drawings, in which: FIG. 1 illustrates the basic initial state of creating a security feature reconstructed by incident light in the plane of the security feature; The image of the security element viewed from above for different rotations of the security element about an axis perpendicular to its plane.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows the essence of creating a static reconstruction of the identification pattern (2) and which forms incident light into a defined, in the space of the static identification pattern 2 regardless of the rotation about the axis 3 perpendicular to the plane of the security element (1). The diffractive element 1 generates an identification pattern 2 in a particular example in the form of an A in the plane of the security element. Each point of the observed identification pattern 2 in space is formed by contributions from at least one of the microdots 6 from the original group of 5 microdots for any rotation of the structure in the horizontal plane. These microdots 6 forming a given pixel 4 are generally different for different rotations.

Fig. 2 shows the rotation of the security element 1 along the axis 3 perpendicular to the plane of the security element 1 by an angle Δα, where the identification pattern 2 remains in its original position. Before rotation, the pixel 4 spatially corresponds to the original group of 5 microdots on the surface of the security element 1, of which one or more microdots 6 contribute to the creation of this pixel 4. After rotating the security element 1 by an angle Δα about axis 3, the static but original group of 5 microdots on the surface of the security element 1 is moved to a different position. The pixel 4 now spatially corresponds to a generally different system of microdots, in this case a rotated system of microdots 7 on the surface of the diffractive element 1, again one or more of the microdots contributing to the creation of the pixel 4.

· · · ♦ · · ♦ · ♦ ♦ · · β • β β β β β β β

Giant. 3 shows a view of the reconstruction of the security element seen from above for different rotations of the diffractive element 1 about an axis perpendicular to its plane, in each case by an angle of 15 °. Part of the image is tied to the security element by position, and therefore rotates with the element including the letters B, and part of the image - the A-pattern 2 is static in space and retains its absolute starting position when the protected object is rotated.

Industrial applicability

The present solution can be used wherever it is necessary to protect an object, document or other product with a more sophisticated security element whose authenticity can be verified by observing a simple visual effect without using any specialized reading device. The authenticity of the security feature is identified by simple rotation of the security feature within a defined range of angles, where the authentic element - the identification pattern - exhibits a visual effect independent of the rotation angle and the observed identification pattern remains static at its original position despite the structure rotation within the defined range.

Claims (6)

PATENT CLAIMS A security device with a static identification pattern, in particular for the protection of objects and documents, wherein the identification image (2) remains static when the protected object is rotated along an axis (3) perpendicular to the security element (1), characterized in that each pixel ( 4) the observed identification pattern (2) generated by the security element (1) is made up of an original group of microdots (5), of which at least one of the original microdots (6) of the original microdots group (5) is contributing to the pixel (4); by rotating the security element (1) about an axis (3) perpendicular to the security element (1), the pixel (4) of the identification pattern (2) according to vztahuχ = r · Δα is formed by a rotated microdots group (7), again at least one or a plurality of microdots from the rotated array (7) of the microdots are contributing to the eye of the observer the same information as one or more microdots (6) of the original array (5) ) microbodies. Security element according to Claim 1, characterized in that some of the microdots (6) are alternatively formed by a micro-grid diffracting the incident light in a selected direction according to the grid equation (M). 3. A security element according to claim 1, characterized in that some microgrids are alternatively superimposed on one another in a single surface. Security element according to claim 1, characterized in that some of the microdots (6) are alternatively formed by a blazed grid allowing the rotation to a full angle of up to 360 °. Security element according to claim 1, characterized in that some microdots (6) are alternatively formed by suitable reflective points with an angle of inclination of the element perpendicular to the mean of the illumination angle and the viewing angle allowing the structure to be rotated to a full angle of up to 360 °. Security element according to Claims 1, 2, 3, 4 and 5, characterized in that the pixels (4) are alternatively positioned generally in space and that the microdots from the plane of the security element (1) from different groups are simultaneously contributing to the pixel micro-points.