DE102015219397A1 - Object with an identification feature arranged for its identification - Google Patents

Abstract

The invention relates to an article with an identification feature arranged for its identification, wherein the identification feature has at least two identification elements in a defined limited area, wherein the first identification element is formed from a printing ink or from an ink, wherein the second identification element as one of pigments of a colorant formed random structure or as a random structure formed of particles of at least one dye, wherein the random structure of the second identification element is formed as an integral part of the ink or the ink of the first identification element, wherein the ink applied to a surface of the object to be identified or ink of first identification element is applied in a grid-like arrangement of pixels, wherein the random structure of the second identification element forming Pigmen te of the colorant or the particles of the at least one dye by coagulation forming a plurality of adjacent pixels of the lattice-shaped arrangement comprising planar structure.

Description

The invention relates to an article with an identification feature arranged according to its identification according to claim 1.

Electromagnetic radiation in a wavelength range of about 380 nm to 790 nm is generally referred to as light spectrum and is perceivable by humans with his eyes as light. Since the sensitivity of the human eye at the perceptual limits does not abruptly, but gradually decreases, an overly precise narrowing of the light spectrum makes little sense. In addition, the color perception for individual wavelengths in humans is individually slightly different pronounced. Therefore, the Commission Internationale de l'Éclairage (CIE) has empirically determined spectral sensitivities for wavelengths and defined a standard valence system to establish a relation between human color perception (color) and the physical causes of a color stimulus (color valence). The CIE standard-valence system captures the totality of human perceivable colors. The wavelength ranges adjacent to the light spectrum are the ultraviolet radiation in the short-wave range and the infrared radiation in the long-wave range.

In classical electrodynamics, light is understood as a high-frequency electromagnetic wave. Radiation optics, also called geometrical optics, makes use of the approximation that the propagation of light through straight beams can be illustrated. This approximation is justified in particular if the dimensions of the object to be examined or of the structure to be examined are large compared with the wavelength of the light. Then all diffraction phenomena can be neglected. Diffraction or Diffraction is the deflection of waves on an obstacle. By diffraction, a wave can propagate into areas of space that would be blocked in a straight path through the obstacle. However, diffraction is no longer negligible if geometric structures play a role whose size is comparable to the wavelength of the waves used. In quantum physics, light is no longer understood as a classical wave, but as a quantum object. Accordingly, the light is composed of individual discrete energy quanta, the so-called photons. A photon is an elementary particle that always moves at the speed of light.

When light encounters matter, matter interacts with the matter and manifests itself in one or more of the following phenomena: Absorption: The energy of the incoming light is absorbed by the matter of a body. This can cause an electron present in matter to be raised to a higher energy level and the body heats up. When the radiation is absorbed by matter regardless of its wavelength, the body appears black. If only a part of the light spectrum is absorbed, the remaining parts of the light spectrum determine the color of the body through subtractive color mixing. If white light strikes a body, the incident light is partially reflected and partially absorbed. When short-wave components of the light spectrum from 380 nm are absorbed by the body, the remitted radiation contains predominantly long-wave components up to 790 nm and the remitted radiation is perceived with the color red. With predominantly long-wave absorption up to 790 nm, the color perception from the reflected light is violet. In the case of electronic excitation of matter, energy can also be released again in the form of radiation. One speaks of spontaneous emission, of fluorescence or, if the process is delayed in time and / or lasts much longer, of phosphorescence. Reflection: On reflecting surfaces, z. B. on a bare surface of a metal, light is reflected by the law of reflection. In this case, the incident light beam and the outgoing light beam as well as the solder lie on the reflecting surface in one plane. Incidence angle and angle of departure are equal to each other. The ratio of the reflected light intensity to the incident light intensity is referred to as reflectance and is material and wavelength dependent. Scattering: The light changes its propagation, but not in a defined direction, as in reflection, but diffusely in all possible spatial directions. Depending on the scattering body, a distinction is made between Compton scattering (on free electrons), Rayleigh scattering (on bound electrons without energy transfer), Raman scattering (on bound electrons with energy transfer) and Mie scattering (on particles whose expansion in the Magnitude of the wavelength is). Refraction: Light is refracted at an interface between two media of different optical density, ie a light beam changes its direction at this interface. Some materials split a light beam into two beams of different polarization. In this case one speaks of a birefringence. Optical activity: Certain media rotate the polarization plane of polarized light. Photo Effect: The photons of the incident radiation dissolve electrons from the irradiated body.

A color stimulus results from absorption and remission (i.e., scattering or reflection) of certain frequency components of visible light. The color stimulus is the physical identification of the radiation of visible light, which causes a perception by direct irritation of the retina of the eye, whereby this perception can be perceived as color. The color stimulus can be from both a primary light source, i. H. from a self-radiator, d. H. from a self-luminous source, as well as from a secondary light source, d. H. emanating from a lit body. In a color stimulus caused by a primary light source, it is called a light color, whereas the color stimulus caused by a secondary light source is referred to as body color. Body colors change the spectral composition of the incident light according to a transmission and remission behavior of the matter of the body in question.

For the color stimulus, a relative spectral radiation distribution S _{λ is} decisive, ie the "irritating" radiation as a function of the wavelength and not in its absolute magnitude or intensity. The spectral distribution which determines the color sensation is called the color-stimulus function φ (λ). In the case of a self-radiator, this function is equal to its spectral distribution S (λ). In the case of a secondary light source, ie a body color, the color stimulus is determined by the product of the beam density factor β (λ) and the spectral distribution of the light source.

Radiometry is the science of measuring and applying electromagnetic radiation. The quantitative measurement of radiation intensities is done with different types of detectors. The detectors for the physical measurement of radiation quantities are called radiometers. These detectors convert part of the radiation into heat or into an electrical signal, which, among other things, can be used to deduce the nature of the radiating surface and its temperature. Photometry or photometry are measuring methods in the wavelength range of the visible light and the ultraviolet spectral range by means of a photometer, wherein a photometer or photometer is an instrument for measuring at least one photometric quantity. Photometric quantities are derived from the associated radiometric quantities. The difference between a photometric quantity and a corresponding radiometric quantity is that in photometry the sensitivity of the observer is taken into account by multiplying the radiometric quantity by a CIE-standardized spectral light-sensitivity curve, which is also referred to as the V-lambda curve becomes. An index v (in noncursive writing), which is attached to the variables by convention, stands for the reference to visible light, ie typically the spectral range from 380 nm to 790 nm. The following photometric variables exist:
The luminous flux, measured in the SI unit lumens (lm), is the radiant power of a light source, weighted with the light sensitivity curve, and corresponds to the radiometric magnitude radiant power, ie the radiant flux or radiant energy per time, measured in the SI unit watts (W ).

The amount of light, measured in the SI unit of lumen-seconds (lms), is the radiant energy of a light source, weighted by the sensitivity curve, and corresponds to the radiometric quantity of radiant energy, i. H. the amount of radiation or the energy of a number of photons transported in an electromagnetic radiation assumed to be a stream of photons measured in the SI unit Joule (J).

The luminous intensity, measured in the SI unit candela (cd), is the luminous flux per solid angle, measured at a great distance from the light source, and corresponds to the radiometric quantity radiation intensity, d. H. the radiant intensity, radiant intensity or radiant flux per solid angle, measured in the SI unit watts per steradian (W / sr). The light intensity indicates how intensively a light source shines in a certain direction. For a spatially isotropically radiating light source, the luminous flux is equal to the luminous intensity multiplied by 4π, the solid solid angle.

Illuminance, measured in the SI unit lux (lx), is the luminous flux per illuminated area, and corresponds to the radiometric magnitude irradiance, ie the radiant flux density or radiant flux per effective receiver area, measured in SI units watts per square meter (W / m ² ). The illuminance indicates how intensively the surface is illuminated.

The specific light emission, measured in the SI unit Lux (lx), is the emitted luminous flux, relative to the size of the light-emitting surface, and corresponds to the radiometric magnitude specific emittance or emission current density, ie the radiative flux per effective transmitter area, measured in the SI Unit watts per square meter (W / m ² ).

The luminance, measured in the SI unit candela per square meter (cd / m ² ), is the luminous intensity of a light source, based on its projected area (perpendicular to the viewing direction), and corresponds to the radiometric quantity radiance, ie the radiation flux per solid angle per effective Transmitter area, measured in SI unit watts per square meter and steradian (W / (m ² sr)). The luminance takes a picture-capturing optical system, for. As the person or a camera, as brightness of a light-emitting surface true.

With the photometric quantities or the corresponding radiometric quantities, properties of a radiation source, a receiver and of irradiated material can be described.

An emission spectrum is the electromagnetic spectrum that is emitted by atoms, molecules or materials without radiating electromagnetic radiation of the same frequency. The counterpart of an emission spectrum is the absorption spectrum. While discrete energy levels cause a line spectrum, energy bands cause a continuous spectrum. An atomic spectrum is the emission spectrum of a single isolated atom, ie the intensity of the light emitted by it as a function of wavelength or frequency. The spectral lines each correspond to the energy difference between two different states of the atom. This energy difference is applied, for example, by an absorbed photon and then emitted in the form of another photon with that energy, that is emitted. This energy (or in the spectrum the line) is discrete, so it can not take any values. This implies that each atom - according to its electron configuration - can only emit particles of discrete wavelength. The wavelengths of the emitted particles are therefore specific to a particular element. The fact that the "lines" in the spectrum ('peaks') are exact curves with a certain width is based on quantum effects. The spectral lines become wider with increasing gas pressure. At very high pressure, the line width can increase to such an extent that one observes a continuum of light similar to a solid. The cause is the more frequent mutual interference of the atoms during the collision. If an electron is completely released from the atom by absorption of a photon, this is called ionization of the atom. For this purpose, depending on the initial state of the electron, a certain minimum energy is necessary. Since ionization becomes possible for a continuous energy range above the minimum energy, a continuum is possible. The reverse process, ie the emission of a photon when an electron is captured, is called recombination of the electron with the positive ion. This process produces continuous radiation, the boundary continuum. While the emission spectrum of dilute gases gives a line spectrum, hot solids and liquids emit a continuous spectrum because the individual atoms additionally interact with each other, thus merging the discrete quantum states. Such a continuous spectrum can be calculated by taking the spectrum of a blackbody (Plancksches Radiation law) of the same temperature multiplied by the absorption coefficient for electromagnetic radiation of the "object" at the respective wavelength.

A solid is matter in the solid state, especially at a temperature of 20 ° C. Solid particles have a certain minimum extent in technical usage, but this is not sharply defined. They are therefore macroscopic body - in contrast to microscopic bodies such. For example, atoms and molecules. One distinguishes between amorphous, d. H. in the smallest scale "shapeless", polycrystalline and crystalline solids. Polycrystalline solids consist of a collection of small single crystals, which are disorganized into a large whole.

An absorption or absorption line spectrum is an electromagnetic spectrum that arises when broadband, in particular white, light radiates matter and light quanta, i. H. Photons of certain wavelengths or wavelengths are absorbed thereby (resonance absorption). The absorbed photons are missing in the passing light, whereby the so-called Fraunhofer lines are formed in the spectrum. Therefore the spectrum at the respective wavelengths is dark or in extreme cases black.

An absorption band is a wavelength interval in which the electromagnetic radiation, e.g. As solar radiation, by chemical substances, eg. As atmospheric gases such as carbon dioxide, carbon monoxide, ozone, methane u. a. is selectively absorbed on the way to the receiver. The originally continuous spectrum of the radiation source arrives at the receiver only with dark gaps, these gaps forming the so-called absorption bands. Certain intervals of the entire wavelength range emitted by the radiation source are no longer present. An image of the spectrum obtained by selective absorption is called band spectrum. An absorption band consists of a larger number of individual, d. H. singular, closely spaced absorption lines. The absorption bands are due to the coupling of electrical vibrational and rotational excitation in molecules, so that no single energy difference is absorbed, but depending on the excitation of the molecules a whole range of energy values, d. H. the absorption spectrum. The various molecules absorb each only in a specific wavelength interval for them. If the photons of the electromagnetic radiation emitted by a radiation source are absorbed by these photons excite atoms, then these are sharply defined amounts of energy and thus wavelengths, and the dark areas are accordingly narrow lines. On the other hand, in molecules, many absorbable energy levels are often close together, forming broader dark areas in the spectrum, i. H. the absorption bands. In any case, the observed absorption spectrum is characteristic of the type of matter that traverses the radiation. Therefore, spectroscopy, usually in different wavelength ranges, is an important method for analyzing substances. Be free atoms, z. B. in a gas or vapor, spectroscopy, the photons are emitted again after absorption, uniformly in all spatial directions. If the light is radiated only from one direction, then in the light which has passed through it is found that for the atomic species at hand, d. H. for the relevant chemical element, typical absorption spectrum as a line spectrum. The light scattered in the other spatial directions shows the corresponding emission spectrum.

In the spectroscopy of solids, a relaxation in the solid can still occur between the absorption and possible emission. In this case, a part of the energy of the photons z. B. converted into heat. In this case, the absorption and emission spectra are not complementary to each other as in the case of the free atoms.

Luminescence is the optical radiation of a physical system, which arises during the transition from an excited state to the ground state. Depending on the type of excitation, a distinction is made between different types of luminescence. So z. B. electroluminescence excited by electric current, z. B. in light emitting diodes (LED). Photoluminescence is excited by photons, with differentiation between phosphorescence and fluorescence depending on the time between excitation and emission of the light. Radioluminescence is excited by an irradiation with alpha or beta radiation or by X-radiation. Superluminescence is produced by optical pumping, whereby spontaneously emitted light is amplified by stimulated emission in an optically active medium. Chemiluminescence is excited by a chemical reaction.

A light-emitting diode (LED) is a semiconductor light-emitting component whose electrical properties correspond to those of a pn-type semiconductor diode. If an electric current flows through the diode in the forward direction, a light emitting diode emits electromagnetic radiation with one of the Semiconductor material and its doping dependent wavelength (λ), wherein this radiation is either visible light or infrared radiation or ultraviolet radiation.

The ability of a solid to absorb light, including a semiconductor, is subject to the condition that the photon energy is absorbed by the excitation of electrons. Since electrons can not be excited at an energetic distance between a valence band and a conduction band of the solid, ie in its so-called bandgap, the energy of a photon must surpass the energy of the bandgap. Otherwise, the photon can not be absorbed. The energy of a photon is coupled to the frequency of the electromagnetic radiation via Planck's constant. If a solid has a bandgap, it is therefore transparent to radiation below a certain frequency or above a certain wavelength (λ), with the exception of special effects. The energy of a photon emitted by the solid is equal to the energy of the bandgap, ie the energy gap between the conduction and valence bands. The energy of the bandgap decreases with increasing temperature due to the thermal expansion of the lattice first quadratically, then more or less linearly, starting from a maximum value at the temperature of zero Kelvin. The temperature dependence of the band gap is material-dependent and can be z. B. with the Varshni formula describe. The size of the band gap, ie the energy gap, determines the energy, ie the frequency, wavelength or color of the radiation or of the emitted light. It can be controlled by the chemical composition of the semiconductor. Thus, the exchange of atoms in the crystal lattice alters the crystalline and / or molecular structure of the material, including its lattice parameters or even its lattice structure. By a selective selection of the semiconductor materials and their doping, the properties of the radiation generated can be varied. In particular, the spectral range and the efficiency can be influenced. For example, light emitting diodes of the frequently used semiconductor material emit indium gallium nitride (InGaN) or gallium nitride (GaN) in the ultraviolet (230 nm <λ <400 nm), violet (400 nm <λ <450 nm), blue (450 nm <λ <) depending on the doping 500 nm) or green (500 nm <λ <570 nm) spectral range. LEDs emit in a limited spectral range Δλ z. B. of maximum Δλ ≈ 30 nm, so their radiation is almost monochromatic. For a light-emitting diode z. B. from the material indium gallium nitride (InGaN, In _x Ga _1-x N), which is a III-V semiconductor, which is formed of the two base substances gallium nitride and indium nitride, resulting in a ratio of 2% indium and 98% Gallium nitride, a bandgap that provides near ultraviolet emission. On the other hand, 20% indium nitride and 80% gallium nitride produce a blue-violet radiation with a wavelength of 420 nm. At a ratio of 30% / 70%, the radiation is 440 nm, which is blue

Color corresponds. Other materials for LEDs form z. B. II-VI compounds or the chemical elements Si and Se.

• a) Es können verschiedene Leuchtdioden z. B. in ein und demselben Bauteil verwendet werden. Blaue Leuchtdioden werden mit gelben oder mit roten und grünen so kombiniert, dass sich ihr Licht gut mischt und damit als weiß erscheint.
• b) Es wird eine blau emittierende LED oder eine UV-LED mit einem Leuchtstoff z. B. in Form einer Lumineszenzschicht aus einem photolumineszierenden Material oder einem Lumineszenzfarbstoff kombiniert. So kann kurzwelliges, höherenergetisches Licht, insbesondere blaues Licht oder eine Ultraviolettstrahlung, in langwelligeres Licht umgewandelt werden. Beispielsweise wird eine blaue LED mit Cer-dotiertem Yttrium-Aluminium-Granat-Pulver kombiniert. Da blaue LEDs den höchsten Wirkungsgrad haben, UV-LEDs hingegen weniger als die Hälfte, ist das die wirtschaftlichste Methode, weißes Licht mittels LED zu erzeugen, aber mit dem Nachteil eines Blaustichs des weißen Lichts. Der Ultraviolett-Anteil, den blaue LEDs am kurzwelligen Ausläufer ihres Strahlungsspektrums aussenden, wird durch die Lumineszenzschicht ebenfalls weitgehend in gelbliches Licht umgewandelt. Bei einem Herstellungsverfahren für weiße LEDs wird z. B. Galliumnitrid epitaktisch auf einen Träger z. B. aus Saphir oder Silizium aufgebracht. So entsteht die erste Schicht des GaN-Halbleiterkristalls. Die lichtemittierende Schicht besteht in der Regel aus InGaN, deren blaues Licht vom Leuchtstoff teilweise in längerwelliges Licht umgewandelt wird. Die Lichtfarbe der LED ist auch zumindest teilweise von der Schichtdicke des Leuchtstoffs abhängig.

White light can with light emitting diodes z. B. be produced by the following methods for additive color mixing:

• a) There may be different LEDs z. B. be used in one and the same component. Blue light-emitting diodes are combined with yellow or with red and green in such a way that their light mixes well and thus appears white.
• b) It is a blue emitting LED or a UV LED with a phosphor z. B. in the form of a luminescent layer of a photoluminescent material or a luminescent dye combined. Thus, short-wave, higher-energy light, in particular blue light or ultraviolet radiation, can be converted into longer-wave light. For example, a blue LED is combined with cerium-doped yttrium-aluminum-garnet powder. Since blue LEDs have the highest efficiency, while UV LEDs are less than half, this is the most economical way to produce white light using LEDs, but with the disadvantage of a blue cast of white light. The ultraviolet component which blue LEDs emit at the short-wave spur of their radiation spectrum is likewise largely converted into yellowish light by the luminescent layer. In a manufacturing process for white LEDs z. B. gallium nitride epitaxially on a support z. B. made of sapphire or silicon. This creates the first layer of the GaN semiconductor crystal. The light-emitting layer is usually InGaN, whose blue light is partially converted by the phosphor into longer-wavelength light. The light color of the LED is also at least partially dependent on the layer thickness of the phosphor.

The aforementioned methods for generating white light are z. B. in the WO 2007/017049 A1 described. By the WO 2007/017049 A1 is also known photonic material with regularly arranged cavities containing at least one colorant, wherein the wall material of the photonic material has dielectric properties and as such acts substantially non-absorbing for the wavelength of an absorption band of the respective colorant and is substantially transparent to the wavelength of a the absorption wavelength excitable emission of the colorant and the cavities so are designed so that radiation of the wavelength of the weak absorption band of the colorant is stored in the photonic material. In this case, radiation from the wavelength range of 250 nm to 500 nm is preferably selected and stored in the photonic material, wherein the radiation is preferably selected from the wavelength range from 380 nm to 480 nm and particularly preferably from an indium gallium nitride, in particular the formula ln _j Ga _j Al _k N, where 0 <i, 0 <j, 0 <k, and i + j + k = 1. The colorant is an emitter for radiation in the range of 550 nm to 700 nm, preferably is a rare earth compound doped with europium, samarium, terbium or praseodymium, preferably with triply positively charged europium ions. The colorant is present in nanoparticulate form, preferably with an average particle size of less than 50 nm (hydraulic diameter determined by means of dynamic light scattering).

In general, such solids are referred to as phosphor, which produce visible light by excitation with short-wave light to the ultraviolet or electron bombardment. Phosphors are often inorganic, crystalline substances, which provide a technically utilizable light output by targeted introduction of impurities in the crystal structure. In this case, purity levels of the starting materials of up to 99.9999% are required. The phosphors are mostly based on oxides or sulfides such as zinc oxide, zinc sulfide, zinc-cadmium sulfide and zinc sulfide selenide, and silicates such as willemite and zinc beryllium silicate. Zinc sulfide is also used in self-luminous radioactive luminescent paints. The doping element determines the luminous color (ZnS: Mn → orange-red, ZnS: Ag → blue, ZnS: Cu → green, ZnS: Ln → depending on the lanthanoid red to blue-green). Parameters such as light color of the fluorescence and phosphorescence, persistence duration and efficiency of energy reproduction are not only dependent on the materials used, but also on their processing such as annealing, grinding, quenching, atmospheric effects during these processes.

By the EP 2 062 960 A1 is a phosphor, in particular a phosphor, which is used in illuminations or in light-emitting devices including LED, wherein the phosphor substantially comprises a silicate and an activating agent ion and has a main chemical composition which is expressed by the following formula: aAO · bA'O · cSiO ₂ : xEu · yLn · zM · δN, wherein A is selected from the group consisting of Sr, Ca, Ba and combinations thereof; A 'is selected from the group consisting of Mg, Zn and combinations thereof; An ion ion is selected from at least one member selected from the group consisting of Nd, Dy, Ho, Tm, La, Ce, Er, Pr, Bi, Sm, Sn, Y, Lu, Ga, Sb, Tb, Mn and Pb; M is selected from the group consisting of Cl, F, B, I and combinations thereof; N is selected from the group consisting of Li +, Na +, K +, Ag + and combinations thereof; a, b, c, x, y, z and δ are molar coefficients; 1.0 ≤ a ≤ 5.0; 0 ≤ b ≤ 2.0; 0.5 ≤ c ≤ 2.5; 0.001 ≤ x ≤ 0.2; 0 ≤ y ≤ 0.5; 0 <z <0.5; 0 <δ <0.2; and wherein 1 ≤ (a + b) / c ≤ 4; and that upon excitation of a light emitting element as an excitation light source having an emission spectrum ranging from UV light to blue light of 240 nm to 475 nm, the phosphor absorbs at least a portion of the light from the excitation light source to produce an emission spectrum having at least two peaks in the range from 370 nm to 760 nm, with the emissions joining together to produce white light. In this case, the phosphor is preferably excited by an excitation light source having an emission maximum in the range of UV light to blue-violet light of 240 nm to 455 nm, this phosphor having a light emission spectrum with two or three maxima in the range of 370 nm to 760 nm generated.

The term colorant is according to DIN 55943: 2001-10 "Colorant Terms" is a collective term for all colorants. The DIN 55943 subdivides the colorants first into organic and inorganic colorants. Each of the two groups is divided into dyes and pigments. Pigments are coloring substances which, unlike dyes, are insoluble in the application medium. In this case, that substance is referred to as the application medium, in which the colorant is incorporated or will. The properties of the pigments are in addition to the chemical structure by their solid state properties such. As crystal structure, crystal modification, particle size and particle size distribution determined. In order to address the respective matter of a dye having optical properties, particles of the respective dye are referred to below, even if these particles are molecules soluble in the application medium or more complex chemical compounds.

Colorants specifically absorb a limited portion of the visible white light and remit the unabsorbed portion of the white light. In this case, the complementary color of the light perceived by a viewer is absorbed by the colorant. The color absorption is based on conjugated double bonds and aromatic bases of the molecules. Upon absorption, conjugated electrons become Double bond system raised to a higher energy state and the colorant molecule gives energy by radiation in another, especially visible wavelength or by heat radiation again from. By changing functional groups on the aromatic, the absorption range of a colorant can be influenced, which groups can be formed as a nitro, sulfonic acid, dimethylamino or hydroxy group. At the same time, this can also influence the chemical reactivity and the color property. For example, an NH ₂ group with its lone pair of electrons has a deepened color. Aromatics, ie aromatic compounds or chemical compounds having at least one aromatic base body, are a class of compounds in organic chemistry, which is characterized in that aromatic molecules have at least one ring system which according to the Hückel rule in conjugated double bonds, lone pairs or unoccupied p orbitals contains a number of 4n + 2 (n = 0, 1, 2, ...) delocalized electrons. This delocalization leads to a special binding system in which no distinction can be made in the ring between single and double bonds. In simple, symmetrical ring systems, such. B. in benzene, so that all bonds are identical. Aromatics are lower in energy and therefore less reactive than non-aromatic double bond systems. In particular, they are not prone to addition reactions. With the Hückel rule, it can be determined whether a chemical compound is an aromatic molecule. A cyclic conjugate molecule is particularly stable with [4n + 2] π electrons (an odd number of electron pairs, such as n = 1, [4 × 1 + 2 = 6], that is, three pairs of electrons) and is referred to as an aromatic.

As already mentioned, the absorption of electromagnetic radiation raises the energy level of electrons in molecules or atoms. This means that approximately a distance between electrons and the respective associated atomic nuclei is increased. The energy required for this is the incident electromagnetic radiation, z. B. the light removed. Since these processes occur under quantum conditions, the absorption of electromagnetic radiation is not continuous, but occurs only in certain jumps, which correspond to the energy difference between the electrons before and after the absorption. This energy difference is inversely proportional to the absorbed wavelength of the incident light and thus determines the color in which the colorant appears.

The property of a substance to be a colorant is thus rooted in its chemical structure. Molecules with σ bonds absorb electromagnetic energy in the X-ray and UV ranges. Molecules with electrons in π bonds, d. H. in unsaturated bonds, on the other hand, are excited by electromagnetic waves (or photons) even at lower energy. Interactions of this kind in the long-wave UV and especially in the visible range of light trigger the color stimulus.

With several conjugated unsaturated bonds in one molecule, the π-electrons can be "smeared", i. H. delocalize, whereby the energetic distance between excited state and ground state decreases and shifts an absorption or emission maximum in the direction of longer wavelengths. In this case, the longer the absorption range is, the longer the wavelength of such unsaturated bonds is conjugated.

There are organic and inorganic chromophores, d. H. Color carrier. Organic chromophores consist of systems of conjugated double bonds such as carotene and / or large aromatic molecules such as methyl red. Inorganic chromophores are often found among the transition metals. Examples are vanadium, chromium, manganese, iron, cobalt, nickel and copper. Depending on the oxidation state and complex formation, these elements can show very different colors. The term "chromophore" refers to that part of a colorant which ensures the basic presence of the color.

Chromophores are molecular structures whose vibrational properties can be significantly influenced by auxochromes (electron donors) and antiauxochromes (electron acceptors), which further shift and / or polarize the delocalized π electrons of the chromophore. Auxochromes or antiauxochromes increase the mesomerism in the molecule by displacing electrons to or from a chromophore group. For example, the absorption spectrum of a chromophore alone need not necessarily be within the visible range of the electromagnetic spectrum. However, if the chromophore is further modified by the mesomeric effect of a substituent, i. d. R. also its absorption spectrum.

Chromophores are therefore the basic structures that contain delocalizable electrons. The type of chromophores influences the hue of the colorant via its absorption maximum, while the frequency of the chromophores influences the color depth. In particular, the following molecular structures act as chromophores: RC = CR; RN = NR; R-NO ₂ ; RC = O; RC = NH; RN = O

• a) Auxochrome: R-OH; R-O-R'; R-NH₂; R-NH-R'; R-NHCO-R'
• b) Antiauxochrome: R₂-C=O; R-NO₂; R-CHO, R-COOH; R-SO₃H; R-C=NR'

In particular, the following functional groups act as auxochromes or antiauxochromes:

• a) Auxochrome: R-OH; RO-R '; R-NH ₂ ; R-NH-R '; R-NHCO-R '
• b) Antiauxochromes: R ₂ -C = O; R-NO ₂ ; R-CHO, R-COOH; R-SO ₃ H; RC = NR '

• a) im Molekülaufbau des Farbmittels selbst,
• b) in seinen Molekül- und Atomschwingungen,
• c) in der Konzentration des Farbmittels sowie
• d) in seinem Bindungszustand am oder im jeweiligen Anwendungsmedium.

The color properties of colorants are therefore justified

• a) in the molecular structure of the colorant itself,
• b) in its molecular and atomic vibrations,
• c) in the concentration of the colorant as well
• d) in its binding state on or in the respective application medium.

The manner of binding of the colorant are thereby z. B. co-determined as a substrate or carrier application medium. The binding of the colorant to a solid or the distribution of a dye in a solution can change the hue used in solvatochromism. Solvatochromism refers to the influence of the color of a dye by a solvent (solvent). The recognizable color of the solution is based on interactions of the dye on the one hand with the solvent molecules and on the mutual interactions of the solvent molecules on the other hand.

Functional colorants fulfill a specific defined function in their application, which is not based solely on an aesthetic color scheme. So z. For example, an indicator dye is a functional colorant.

• a) Licht bei einer bestimmten Wellenlänge absorbieren und das absorbierte Licht in Wärme umwandeln,
• b) Licht bei einer anderen Wellenlänge wieder emittieren, z. B. als phosphoreszierende Marker oder z. B. in Form von Fluoreszenz oder Chemilumineszenz,
• c) die Polarisationsrichtung des Lichts verändern, z. B. bei der Frequenzverdoppelung oder als optische Schalter,
• d) elektrische Phänomene bewirken,
• e) fotochemische Prozesse ermöglichen.

From the knowledge of the color absorption of aromatic or polyunsaturated compounds according to the Hückel rule can be prepared special colorants, the

• a) absorb light at a certain wavelength and convert the absorbed light into heat,
• b) emit light at a different wavelength again, z. B. as phosphorescent marker or z. In the form of fluorescence or chemiluminescence,
• c) change the polarization direction of the light, z. In frequency doubling or as optical switches,
• d) cause electrical phenomena,
• e) enable photochemical processes.

A particularly interesting application medium for colorants in the following are printing inks used in printing technology. Printing inks are colorant-containing mixtures which are transferred in particular by means of a printing form to a printing material and form a layer there which dries. Printing inks are suitable for coloring surfaces in technical and industrial processes in such a way that images and text are displayed. Printing inks consist of dispersed, d. H. from i. d. R. extremely finely dispersed pigments, binders and organic solvents. The printing ink black contains pigments of carbon black, in particular carbon black. Colored pigments are extracted from minerals or chemically produced.

The ink is to realize a required hue on a substrate, the hue can be specified as a color location in a color space. The optical properties of a printing ink are dependent on the printing process used for the inking, the printing substrate, the location of the observer and the light source under which the printed product is viewed.

The mechanical properties of printing inks are also called rheological properties. Printing inks for printing processes in which the inking takes place by rolling, for. B. in offset printing, high pressure or gravure printing, require a good transport of the ink over the ink rollers and low aerosol formation. The color transport is determined by the tack of the ink. The tack is the force necessary to separate an ink film. It is a complex ratio of viscosity, cohesion and adhesion and is measured in the ink test as tack. Aerosol formation is the formation of a color mist and color threads at high print speeds. These aerosols are undesirable. The aerosol formation is strongly temperature-dependent, as it correlates directly with the viscosity.

• a) Farbmitteln, d. h. aus Pigmenten oder Farbstoffen, für die Farbigkeit,
• b) Bindemitteln, hauptsächlich aus Harzen (Festharze, Alkydharze), um die Farbmittel auf dem Bedruckstoff zu befestigen,
• c) Hilfsstoffen zum Einstellen der rheologischen Eigenschaften, z. B. zur Beeinflussung von Trocknung, Glanz oder Oberflächenhärte.

Printing inks consist of:

• a) colorants, ie pigments or dyes, for the colouration,
• b) binders, mainly of resins (solid resins, alkyd resins) to fix the colorants on the substrate,
• c) auxiliaries for adjusting the rheological properties, for. B. for influencing drying, gloss or surface hardness.

Since the layer thicknesses of the printing inks applied to the printing substrate are very low (typically about 1 μm to 8 μm, in offset printing preferably 0.7 μm to 2.5 μm), in particular high-color pigments are used. Most printing inks consist of a dispersion (actually: suspension) of pigments in a carrier fluid and are thus a heterogeneous substance mixture consisting of a liquid and finely distributed solids.

Pigments are organic, inorganic or synthetic crystalline powders. Organic pigments are extracted from petroleum and used to make cyan, magenta, yellow and spot colors. Organic pigments are less stable to temperature. Inorganic pigments are usually special blacks for black and titanium (IV) oxide for opaque white. Carbon black is inorganic by definition. Most inorganic pigments are characterized by the fact that they do not react chemically with the oxygen of the air, are therefore extremely resistant to aging and retain their color practically indefinitely. Finely ground metal pigments are used for metal effects. Silver effects are achieved by aluminum bronze. Gold effects can be achieved by using brass bronze or aluminum bronze with yellow / orange pigment. Luminescent colors are caused by UV-active pigments in the printing ink. Pigments are insoluble in the printing ink and are generally harmless to health. Radioactive bulbs are not counted among the pigments, although they are insoluble in the application medium. They are self-illuminants whose radiation is not caused by UV radiation or daylight, but by radioactive excitation.

Dyes allow cleaner colors than pigments because they reflect light with a narrower spectrum. Dyes are soluble on a molecular basis in water, alcohol and fats. Dyes, however, tend to fade under the influence of UV radiation, so they are not as colorfast as pigments. In addition, most dyes are toxic and therefore unsuitable for the coloring of commodities.

The pigments of the printing ink are in the binder, i. H. dispersed in a dispersant, d. H. finely distributed. The binder allows good wetting of the individual pigments and prevents sticking of pigments to agglomerates. The binders bond the printing ink on the substrate during printing and determine the viscosity.

A typical offset ink contains pigments in a mass fraction between 12% and 18%.

Pigments typically arise in the form of primary particles, in particular in the form of angular primary particles. The primary particles can grow together to form aggregates via their surfaces. Agglomerates are when primary particles and / or aggregates are connected by their respective corners and / or edges. By a dispersing process (dispersion) when incorporating the pigments into the relevant application medium, the pigment agglomerates are comminuted. This results in smaller agglomerates, aggregates and primary particles. These, if present, are wetted by a dispersing medium or dispersing agent. Ideally, they are distributed statistically via the application medium.

For applications in safety technology z. B. by the WO 00/059731 A1 and the WO 2012/083469 A1 Color pigments have become known, which belong to the substance class of retinal proteins. An important member of the retinal proteins is bacteriorhodopsin (BR). The protein of the BR consists of 248 amino acids, which, arranged in seven approximately parallel alpha helices, pass through a cell membrane and form a pore. In this pore is a bound to the protein retinal molecule. Retinal is the chromophore of the molecule and bound to the amine function of the amino acid Lys216 via an imine bond, usually referred to as Schiff's base in this context. Under physiological conditions, the chromophore is present only as an all-trans and 13-cis isomer. The isomerization takes place under the action of light. BR forms two-dimensional crystalline regions in the cell membrane of Halobacterium salinarum, assembled to form trimers. These areas, up to five microns in size, in which BR trimers exist in a two-dimensional hexagonal arrangement in the lipid bilayer are called purple membrane (PM). The embedding of the BR in the purple membrane leads to a remarkable stability of the protein against physical-chemical influences. Thus, the color and photochemical activity of the PM are maintained in the presence of oxygen and in the dry state.

BR can be considered as a light energy driven molecular machine that pumps protons. Initiated by the light-induced isomerization of the chromophore and driven by changes in the proton affinities of amino acid functions, in a multi-step process, protons are shifted from a cytoplasmic to an extracellular site through the pore of the protein. Triggering the directed proton shift is the isomerization of the retinal chromophore due to Light absorption. The chromophore is in the unexposed state as a mixture of all-trans and 13-cis retinal, after exposure only in the 13-cis configuration. As a result of the embedding of the chromophore, this results in structural changes of the protein, which has a direct effect on the initially protonated state of Schiff's base. This proton is located after the isomerization in an energetically unfavorable environment and is delivered to the immediate interaction partner of Schiff's base, Asp85, in extracellular direction. This is followed by a series of four further unidirectional proton shifts, before finally the initial state of the protein is restored and a new cycle can be run through. This light-driven pumping of protons is linked to a cyclic sequence of spectroscopically distinct states of the protein. This episode is called a photocycle. The photocycle cycling as a result of exposure is associated with a reversible color change from purple (B state, absorption maximum 570 nm) to yellow (M state, absorption maximum 410 nm).

In the aforementioned WO 00/059731 A1 Now, a method for securing the authenticity of articles has been described in which a photochromic preparation in the form of an ink containing bacteriorhodopsin as a photochromic fraction, is applied to the article, wherein the irradiation of this photochromic preparation with light in the visible wavelength range to a state change leads, which is detectable for the purpose of authenticity testing.

As the ink is an intensely colored liquid for use z. B. referred to in the word processing or goods labeling. Ink consists of a solution or dispersion of colorants in water or other solvent and contains little or no binder. Inks without binders are therefore not printing inks. There are different types of ink, for. As inks with soluble colorants or with insoluble colorants, water-soluble inks, solvent-based inks or pigmented inks, which pigments, unlike dyes in the application medium can not chemically solve. While pigments have a characteristic intrinsic coloration, the color of a dissolved dye may depend on the solvent used, whereby the ink may have a different color than the dried ink application. The particles of the dye of the ink of the first identification element are z. B. in a mass fraction between 1% and 15% in the ink in question.

By the WO 2012/083469 A1 a method for verifying the authenticity of a security feature, in particular on a security document, wherein the security feature in the visible area under excitation of a flash of light shows a change, wherein at least a first image of the unexcited security feature is recorded with a mobile phone, the mobile phone is a camera having built-in flash function, wherein at least a second image of the stimulated with the flash function using the safety feature is recorded with the same mobile phone, the order of the two aforementioned recordings can also be performed vice versa. In the mobile phone, an authentication check is then performed on the mobile phone from the at least two pictures with the aid of a suitable data processing program and the result of this check is output via a display or an acoustic interface on the mobile phone.

Under a flash light is understood in photography, a lighting device that provides for an object illumination at the moment of recording by means of a flash of light. An electronic flash device is a z. B. in a data acquisition device or in an image pickup device, for. B. in a camera or in a mobile phone, z. B. in a smartphone built-in flash unit that works with a flash tube based on a flash lamp. Electronic flash units usually work with xenon-filled flash tubes. When the flash unit is triggered, a capacitor previously charged to a few 100 volts, e.g. B. discharged a cylindrical electrolytic capacitor or a plate-shaped flat-building polymer capacitor, whereby in the interior of the flash tube, a very short, light gas discharge is generated. A typical lighting duration of this flash is between about 1/300 and 1 / 40,000 seconds depending on the power and control. The emitted spectral range of a xenon-filled flash tube extends continuously from the ultraviolet range over the visible range to the infrared range, depending on the design of the flash tube, a particularly high radiation intensity in the wavelength range z. B. between 300 nm and 500 nm or between 880 nm and 1000 nm.

Alternatively, LEDs are used in mobile phones or smart phones, preferably power LEDs as a flash unit, z. For example, a flash LED of the Luxeon product line from Philips Lumileds Lighting Company, San Jose, California, USA, or the Oslux or Ceramos product line from OSRAM Opto Semiconductors GmbH, Regensburg, DE. These flashlight LEDs have i. d. R. two spectral maxima, namely at about 440 nm (blue) and at about 570 nm (yellow), resulting in at least approximately white light for a viewer in the additive color mixture.

By the WO 2013/054290 A1 For example, a security element or document having a support and at least one first feature attached to the support having a dynamic effect is known, the dynamic effect due to excitation by illumination having a selected wavelength or wavelength band, producing an optical spectral response dynamically changing the optical spectral response during illumination excitation over an observable period of time between a plurality of color phenomena, wherein the first dynamic effect feature is located in a region of the carrier proximate to an adjacent feature mounted on the carrier the adjacent feature has a color impression selected such that this color impression enhances and / or supplements at least one color impression of the first feature with the dynamic effect. This dynamic effect is preferably caused by a pigment, as z. B. in the WO 2007/005354 A2 described which pigment has more than one color impression under a uniform prolonged irradiation with electromagnetic radiation. According to the WO 2007/005354 A2 For example, such a pigment comprises a core having a carrier substance and either a fluorescent material or a phosphorescent material, the core having a substantially spherical shape, wherein a shell surrounding the core is provided, the shell containing photochromic material which is in the radiation of a first light source having a first optical property and having a second optical property in the radiation of a second light source, the second light source containing a quantity of wavelengths insufficient in the first light source, the second optical property being one of the fluorescent material or The radiation emitted by the phosphorescent material is attenuated. The first optical property is z. B. substantially transparent. The second light source comprises z. B. ultraviolet wavelengths.

By the WO 2015/114 540 A2 For example, a method and material for passively frustrating scanner based replication methods are known.

In the EP 2 637 145 A1 there is proposed a method for authenticating and / or identifying a document or article in which circularly polarizing liquid crystals are contained in a stochastic distribution ink, ie random distribution, by means of a circular polarization of incident light caused by the liquid crystals, the authenticity of that document Article is checked. Such liquid crystals have a cholesteric phase with a nematic order with continuously rotating preferential orientation. This results in a helical superstructure with a periodicity of typically several 100 nm. The thus continuously twisted optical medium acts as a one-dimensional photonic crystal with a photonic bandgap for circularly polarized light with the same handedness as the helical order. Cholesteric liquid crystal films therefore exhibit selective reflection of circularly polarized light. In contrast to reflection on metallic or dielectric mirrors, the handedness of the circular polarization is retained in cholesteric liquid-crystal films.

By the WO 2004/070667 A2 For example, there is known a method of producing a security tag in which the security tag contains a random pattern. The security identifier is z. B. formed by the reflective surface of each object to be marked. Alternatively, the safety mark of particles, e.g. As colored particles, pigments, effect pigments, sand, dust, crystals (eg salt crystals of different colors), ferromagnetic, magnetizable, permanent magnetic, fluorescent, phosphorescent, iridescent, opalescent or radioactive particles. The particular machine-readable random pattern is applied to a product or a label. From a read random pattern, a fingerprint is extracted in the form of a data set containing the individual features of the pattern. This fingerprint is saved individually for each security code. During authentication, the fingerprint is extracted again and the match with the stored fingerprint is verified.

Suitable particles in safety characteristics are, for example, organic and inorganic, especially inorganic fluorescent particles, such as those offered by the company Leuchtstoffwerk Breitungen GmbH (98597 Breitungen, www.leuchtstoffwerk.com). Also suitable are crystals, for. As platelet-shaped crystals, liquid crystals, reflective pigments of at least two layers with different refractive index, effect pigments (interference pigments, pearlescent and metallic luster pigments). Effect pigments, for example, the one sold under the trade names Iriodin ^® / Afflair ^® and Colourstream ^® from Merck KGaA, Darmstadt, and also under the trade name Helicone ^® by the company Wacker Chemie, Burghausen. A particular advantage of reflective particles is the fact that a) they are subject to almost no wear by light in contrast to fluorescent particles and b) depending on the viewing and illumination angle different random patterns arise. Such changes arise z. For example, when looking at the effect pigments, each individual pigment is like a microscopic mirror for light of a specific wavelength acts to reflect this light in its random spatial orientation, creating three-dimensional random patterns. The particles used have, for example, a diameter between 0.1 μm and 1 μm, between 1 μm and 10 μm, between 10 μm and 80 μm, between 80 μm and 150 μm or between 150 μm and 2000 μm, and in each case a thickness of up to 50 μm, preferably up to 10 μm, particularly preferably up to 3 μm. The particles are preferably introduced into a matrix (carrier). The resulting mixture is used to coat objects. Suitable as matrix are paints and varnishes, preferably water, solvent, powder, UV varnishes, epoxy resins, plastics (eg polyethylene), ethyl acetate and comparable materials, paraffins, waxes and wax-like coatings (eg Flexane ). The particles can also be incorporated in printing inks. Preference is given to printing inks for screen, gravure, flexographic and offset printing, the ink layer thickness being <= 20 μm, preferably <= 10 μm, particularly preferably <= 5 μm, very particularly preferably <= 3 μm. The concentration in percent by weight of the particles in the matrix is between 0.01% and 30%, preferably between 0.01% and 1%, between 1% and 10%, and between 10% and 30%, particularly preferably between 0.01 % and 1% and between 10% and 15%.

A stochastic distribution, ie a random distribution of optically active particles in a layer with readable information for the authentication and / or identification of a security feature is z. B. also in the WO 2006/078220 A1 described, wherein these particles have a length extension preferably in the range between 10 nm and 500 microns.

Likewise describes the US 2001/0010333 A1 Random pattern with optically detectable colored fibers or filaments to make an object unique, and thus after illumination with a light source by the detection of the optical pattern of the object z. B. by means of a photo sensor to make this object identifiable.

Also the WO 2007/131043 A2 discloses an object to be authenticated having a substrate and a mark on the substrate, the mark comprising a luminescent material, this material being distributed in a random pattern, the luminescent material having photoluminescence with a quantum efficiency of at least 10 percent. The marker has particles with the luminescent material, these particles being distributed in the random pattern. The particles have a size in the nanometer range.

Also the WO 2013/144645 A1 relates to a method for generating a mark to distinguish between genuine and counterfeit goods, wherein at least one coding is applied to a surface, wherein the coding is created randomly, so that the coding has a unique pattern when of a certain kind is subjected to stimulus. It can also be applied to a variety of codes. The unique pattern arises z. B. from the fact that the position of elements of the coding is visible only under UV radiation, that the visible color of the elements of the coding is visible only under UV radiation, or that the position of the elements of the coding and the visible color of the elements Coding under IR radiation are visible.

Furthermore, from the WO 2010/023243 A1 an identification feature for the identification of an object is known which comprises at least two identification elements, wherein at least a first of the identification elements is given by at least one defined limited surface with a defined diffractive surface structure, which is visible by light irradiation in the visual region, and wherein at least a second of the identification elements is provided within an optical detection field, which at least partially detects the defined limited surface of the first identification element, wherein the first and the second identification element are each an integral part of the object. Preferably, the at least one second identification element is given by a random structure in a surface of the second identification element or the object, wherein the random structure of the second identification element z. B. is integrated in the defined diffractive surface structure of the first identification element. The at least one second identification element is z. B. not visible. To identify the object, the position at which the at least one second identification element is arranged relative to the at least one first identification element is stored. Further, identification information unique to the at least one second identification element is stored. For identification, an image of the first identification element is compared with the stored data.

By the DE 28 29 778 A1 is a mark such. B. a credit card or card with individual features known, these features are present on or in the map area in random distribution and physically scanned, to produce a reproducible, the random distribution of the features corresponding scan size on or in the map is provided with a scannable by optical means and contrasting the environment track is provided, the optical properties of which is modulated by the random distribution of lying with the track features. The features are z. B. absorbing and / or scattering structures in one or more levels of the stamp, the structures z. B. storages in the layers of the stamp are. The line has z. B. in random distribution fluorescent particles that vary in size and in their mutual distance from each other.

By the DE 196 11 383 A1 a data carrier with an optically variable security element arranged on its surface is known, wherein the security element in each case imparts a different visual impression at at least two viewing angles, wherein the data carrier is provided with a background layer at least in a partial area, which has at least one authenticity feature, and wherein the security element at least partially overlaps this background layer, the background layer being arranged such that it is not completely covered by the security element in at least one direction. The background layer contains z. B. at least one authenticity feature from the group of luminescent, metallic, magnetic electrically conductive substances or optically variable pigments. In the background layer are z. B. visually and / or machine readable information.

By the WO 2013/034471 A1 a device for detecting a document is known, the document having a security feature with wavelength conversion properties, comprising: a) a light-generating device, which is designed to illuminate the security feature for the emission of light with excitation light; b) an image pickup device configured to receive a light emitted by the security feature in response to the excitation light to obtain an emission pickup, the image pickup device further configured to receive light emitted by the security feature in response to a reference light to obtain a reference pickup ; and c) a processor configured to recognize the document based on the emission recording and the reference recording. In this case, the reference light z. B. white light, in particular daylight, or the light generating device is designed to generate the reference light, in particular as a continuous light during reference recording, or the light generating device is designed to generate reference light pulses as the reference light during reference recording. The processor is z. B. configured to compare the emission recording with the reference recording to obtain a comparison result and to recognize the document on the basis of the comparison result, wherein the reference light in particular has a predetermined wavelength, and wherein the processor is formed, a wavelength difference between the predetermined wavelength and at least one wavelength of the emission light, or a temporal wavelength characteristic of the emission light with respect to the predetermined wavelength, in particular a time course of a wavelength amplitude or wavelength differences, to determine the comparison result. The device is preferably a mobile communication device, in particular a smartphone, wherein the light generating device is an LED flash unit of the mobile communication device, and wherein the image pickup device is a digital camera of the mobile communication device. Alternatively or additionally, the device comprises a transceiver unit, which is designed to emit the emission recording or the reference recording or a comparison result of a comparison of the emission recording with the reference recording via a communication network to a remote server for the purpose of document recognition and, in response thereto, to receive a result of the document recognition. The device comprises a control device for activating the light-generating device in order to generate excitation light and / or reference light. The control device can be set up in terms of programming and, for example, be designed to execute a computer program that can be an application software (APP). The security feature exhibiting wavelength conversion properties may include, for example, siliceous pigments, especially silicate phosphorous pigments, silicate, sulfide, nitride, YAG, TAG, thiogallate phosphorous pigments added to a printing ink. Such a security feature emits a color-shifted light spectrum responsive to blue light excitation at the wavelength of about 400 nm, which may include, for example, green, yellow, orange, and / or red light. To excite such a security feature, it is therefore possible to use an LED whose light emission spectrum comprises blue light in a wavelength range between 390 nm and 470 nm. The document recognition can therefore be performed by means of an ordinary smartphone equipped with an LED flash unit. The excitation light may therefore comprise or be blue light in a wavelength range from 390 nm to 470 nm, preferably in a wavelength range between 430 nm and 460 nm. For this purpose, the light generating device can comprise an LED for generating continuous light or flash light or pulsed light. In response to the excitation with the excitation light, the security feature is excited to emit light. Due to the wavelength conversion properties of the security feature, which can be realized, for example, by the use of a silicate compound, such as silicate phosphor, this emits Security feature Light that has a wavelength that differs from a wavelength of the excitation light. The emission recording thus contains information about a wavelength spectrum emitted by the security feature in response to the excitation light. By analogy, the reference receptacle includes information about a reference wavelength spectrum that is emissive by the security feature in response to the reference light.

By the EP 2 698 404 A1 For example, in order to verify authenticity and identity, a group of identifying information is known, the information serving for identification being identifiable by an enlargement or amplification, the group including a first information element and a second information element, the second information element not being augmented by any magnification or gain can be identified with which the first information element is identified.

• a) Vorbehandeln der Oberfläche des Artikels;
• b) Einfärben der Oberfläche des Artikels mit einer Farbstofflösung, die einen organischen Farbstoff und ein organisches Lösungsmittel enthält;
• c) Reinigen und Trocknen der Oberfläche des Artikels;
• d) Gravieren durch zumindest teilweises Abtragen der Oberfläche des Artikels.

By the WO 2013/060831 A2 For information encoding purposes and as a security feature, there is known a method of identifying an article comprising a shape memory polymer (FGP) having a visually and / or machine readable graphical element on the surface of the article, comprising the steps of:

• a) pretreating the surface of the article;
• b) inking the surface of the article with a dye solution containing an organic dye and an organic solvent;
• c) cleaning and drying the surface of the article;
• d) engraving by at least partially removing the surface of the article.

As shape memory polymers (FGP), plastics are generally referred to which, after being transformed, can apparently "remember" their former, outer shape and thus have a shape memory. To retrieve the former form, the FGP must be exposed to a stimulus. For example, this stimulus may be a supply of heat by directly or indirectly heating the affected FGP. Direct heating of the FGP may be from the outside by hot air, by IR radiation, for example by exposure to sunlight or the air flow of a hot-air fan or by direct contact with a heat storage medium, such as a previously heated fluid. For example, the heat can be supplied by immersion in warm water.

In a on 16.04.2014 under the Internet address http://iopscience.iop.org/0957-4484/23/39/395201/cites called abstract of the document Jeevan M Meruga et al., Published by the Institute of Physics (IOP) at the University of South Dakota and the South Dakota School of Mines and Technology on September 11, 2006, "Security Printing of Covert Quick Response Codes Using Upconverting Nanoparticle Inks" 2012 in IOP Publishing's Journal Nanotechnology, Volume 23, No. 395201, doi: 10.1088 / 0957-4484 / 23/39/395201 , a quick response (QR) code printed on a substrate is described, which QR code is not visible under normal daylight conditions, but becomes readable by irradiation with near infrared radiation, the visualized QR code then being readable can be detected by a camera of a smartphone. This QR code is z. B. used for authenticity of banknotes, (value) documents or objects. The QR code can be incorporated with a microscopic message that z. B. is readable only with a microscope. The QR code is generated by means of a CAD system. The QR code is z. B. from a mixture of β-NaYF ₄ nanoparticles with lanthanides, z. Yb ³⁺ / Er ³⁺ and / or Yb ³⁺ / Tm ³⁺ , and green and blue fluorescent inks. The term lanthanides refers to the chemical element lanthanum and the 14 elements in the periodic table on the lanthanum cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. All lanthanoids are silvery, relatively soft and reactive metals and are part of the group of rare earth metals.

The QR code described in the abovementioned abstract is printed on the carrier material in a direct printing process using an aerosol jet printer. Details of an aerosol jet printer are z. B. in the WO 2006/065978 A2 described. An aerosol jet printer first atomises a printing ink having a viscosity between 1 cP and 1,000 cP into fine droplets having a size of 1 μm to 5 μm, preferably from 1 μm to 2 μm, and introduces these droplets into a first gas stream first gas stream which transports the thus aerosolized ink to a printhead. On the printhead, a second gas stream arranged annularly around the first gas stream is provided, by means of which the first gas stream conveying the aerosolized ink is reduced to a diameter of z. B. is collimated less than 10 microns. Both gas streams leave a printing material nozzle of the printhead at high speed and transfer the fine droplets of the ink to the nozzle of the printhead at a distance of z. B. 1 mm to 5 mm arranged substrate. Such an aerosol jet printer reached a resolution of less than 10 μm, ie more than 2,500 dpi. An aerosol jet printer differs accordingly in its mode of operation and in its construction from an inkjet printer. Differences to an inkjet printer exist z. B. in that the size of a ejected from an inkjet printer drop of ink z. B. at about 30 microns and the volume of an inkjet printer ejected drop of ink so that it is about two hundred times greater than an aerosol jet printer. Also, an inkjet printer typically uses ink with a viscosity of between 8 cP and 12 cP, which is a significantly reduced range compared to an aerosol jet printer.

A code is an agreement on a set of signs or meaning carriers for the purpose of an information exchange. The characters or meaning carriers of a code can be visually readable or haptically detectable or not directly usable by humans, but can be read by means of a technical device, ie. H. be machine-readable. A code is z. As well as a visually readable or haptic detectable font, since a font is a sign system for the preservation and dissemination of encoded information. The characters of a font can be z. B. each act on an alphanumeric character or another character. The meaning carriers agreed for a particular code are, for example, Each is, for example, a pictograph that represents something material or an ideogram representing an abstract concept.

In the merchandise management or logistics, various machine-readable, in particular opto-electronically readable, z. B. with a CCD camera or with a CMOS camera or with a scanner detectable codes, eg. As bar codes, using each of which information z. B. about a product in a sequence of different characters, eg. B. different width black and white stripes ("strokes") is shown. Two-dimensional codes are defined as 2D code or 2D bar code, which consist of differently wide lines or dots and intervening gaps with the highest possible contrast. In contrast to the one-dimensional barcodes (English barcode), the data in a 2D code is not coded in one direction (one-dimensional), but matrix-shaped in an area over two dimensions. Examples of a 2D code are those in the international Standard ISO / IEC 16022 defined DataMatrix code or the QR code according to ISO / IEC 18004 or the MaxiCode developed by UPS for rapid identification, tracking, and sorting of packets or in the Standard ISO / IEC 24778 coded Aztec code.

The two-dimensional QR code consists of a rectangular, mostly square pixel pattern, wherein the individual pixels or symbol elements consist of contrasting, preferably white and black squares and a z. B. encoded with a mathematical algorithm information content thus represent binary. A QR code contains at least 21 × 21 and a maximum of 177 × 177 symbol elements. A QR code is by means of a smartphone with a camera, in particular with a semiconductor camera, and with a trained as a "QR Code Reader" program, d. H. a so-called APP, readable, with the reading i. d. R. omnidirectional is possible. The reading is in particular a picture interpretation based on the recorded contrast values. A QR code arranged on a carrier contains markings for identifying its position and orientation at defined locations. Also, at further defined locations in the pixel pattern, information for resolution and version of the pixel pattern and data format of the data stored in the pixel pattern and for error correction are stored, one of a set of allowable error correction levels selected error correction stage during the generation of the respective QR code is determined. Thus, four error-correcting error correction levels L, M, Q and H were determined, according to which 7% (level L), 15%, 25% or 30% (level H) z. B. due to destruction or incorrect production unreadable data can be restored. Each QR code can encode up to 7,089 numbers or 4,296 letters.

With respect to an array of characters or meaning carriers associated with a code, pixels are pixels or pixels which are each assigned a color value in a graphic, in particular a raster graphic, a raster graphic representing an image in the form of computer-readable data. A raster graphics thus consists of a lattice-like arrangement of pixels, that is to say an arrangement in a plurality of respectively adjacent columns and these columns each intersecting rows.

Contrast refers to a difference between bright and dark areas or colors of an image. The contrast is a distinguishing feature for a brightness curve of an image or at least between two pixels. The range of contrast or dynamics describes the intensity difference between the brightest and darkest points of an image. The contrast is defined by the maximum luminance and minimum luminance present in the image or between the pixels. Different intensities of the respective luminance are perceived by the human eye according to the Weber-Fechner law not linear, but logarithmic. So that a visual or an optical system, eg. As an eye or a camera can perceive an object, this object must be sufficiently large and have a sufficiently high contrast. This is understood to mean the limit of visibility that is reached when objects that are viewed and z. B. imaged on the retina in the human eye or on an image sensor in a camera, no longer delineate the contour and contrast of the surrounding luminance. This means that the recognizability of objects depends essentially on the ability of the visual or optical system to perceive brightness differences. Thus, for the perception of an object a certain minimum contrast is required, which is higher in weak ambient light conditions than in brighter light.

In principle, an object can only be perceived optically if the relevant object at the same time with respect to the visual or optical system which detects this object at the time of image acquisition or image acquisition has the following four

• a) Mindestleuchtdichte
• b) Mindestkontrast
• c) Mindestgröße
• d) Mindestdarbietungsdauer

Minimum requirements met:

• a) minimum luminance
• b) minimum contrast
• c) minimum size
• d) Minimum duration of the performance

The invention has for its object to provide an object with an identification feature arranged for its identification, the identity and / or authenticity is reliable and inexpensive detectable.

The object is achieved by the features of claim 1. Advantageous embodiments and / or developments emerge from the dependent claims.

The advantages that can be achieved with the invention are, in particular, that the claimed identification feature can be mass-produced in a simple manner and inexpensively in a printing method that can be executed with a printing press. The identification feature contains in a defined limited area a plurality of identification elements for the identification of an object, of which, however, an identification element in the visual area is not recognizable and thus usually remains hidden to a human observer. A first identification element is preferably designed as an arrangement of characters and / or meaning carriers belonging to a code. In an advantageous embodiment, the first identification element is designed as an arrangement of characters or meaning carriers of a multi-dimensional code, for. B. in the form of a pixel pattern having QR code. Such a trained first identification element is both high device complexity and both generated and machine-readable. For reading already enough, a conventional smartphone that is equipped with a camera and a suitable for reading a QR code app, d. H. Application software features.

The second identification element is formed as a random structure formed of pigments or of a dye, this random structure being recognizable only by irradiation with electromagnetic energy of a specific wavelength in the visual range and thereby being photographically imaged. The random structure makes the identification feature unique, so that on the basis of the second identification element, a check of the authenticity and / or identity of the object bearing the relevant identification feature z. B. is easily possible by comparison with a previously created pattern image. The pigments or the at least one dye of the second identification element are contained in a printing ink or in an ink, so that z. B. from this ink or ink formed pixels of the first identification element can be arranged by means of a printing forme-bound printing process or by means of a pressure-formless printing process on the object.

On the basis of and including the previously given general explanations on scientific and / or technical facts in the drawings, an embodiment of the invention is shown and will be described in more detail below.

They show by way of example:

1 an identifier with a QR code;

2 a representation of a random structure within the QR code;

3 a planar formation of the random structure within the QR code.

1 shows by way of example a preferably formed by a printing device of a printing machine, in particular in an inkjet printing process identification feature 01 with several identification elements for the identification and / or authentication of this identification feature 01 carrying object, wherein the identification feature 01 z. B. is arranged on a surface of this article. The identification elements of the identification feature 01 are within a defined limited area on or on the object. All about the relevant identification feature 01 belonging identification elements are arranged within the area containing the relevant identification feature 01 occupies the surface of the object in question. Thus, at least a first identification element and a second identification element are present in this same area, wherein the second identification element has the function of a security feature. The first identification element is preferably designed as an arrangement of code-associated characters and / or meaning carriers, wherein each of the characters or meaning carriers of this arrangement is in each case designed as a pixel-based graphic, these pixels being applied by application of an ink or an ink are formed on the surface of the subject or are. In another embodiment, the first identification element is not used as a particular machine-readable information carrier, but forms only the environment for the second identification element. The pigments or the particles of the at least one dye of the second identification element are contained in the printing ink or in the ink. The second identification element comprising the pigments or the particles of the at least one dye is therefore applied together with the first identification element formed from the printing ink or the ink in the same or only a single working step on the surface of the relevant object. The second identification element is thus at the time of the arrangement of the identification feature 01 on the surface of the object in question always a part of the first identification element and not readily separable from the first identification element.

In an advantageous embodiment variant, the first identification element is designed as a multi-dimensional code, for. B. as a two-dimensional code having a pixel pattern, in particular as a QR code. In the case of the embodiment as a pixel pattern, at least two contrasting configurations of pixels, that is to say relative to each other, form an optical contrast in the relevant pixel pattern 02 There are at least two different types of pixels 02 available. These pixels 02 are in the relevant first identification element for the purpose of their visual perception in at least two different shades, z. B. designed in a color pairing, z. Black / White or Blue / Yellow or Red / Green. Of course, other color pairings or the use of more than two shades are possible, as long as the shades used have sufficient contrast for the optical perception made with an optical or visual system. The contrast can then be considered sufficient if the different sorts of pixels 02 as such from the optical or visual system, e.g. B. from a data acquisition device or image recording device, in particular a scanner or a (semiconductor) camera, z. B. with a CCD image sensor or with a CMOS image sensor, reliably visually perceptible and the different configurations of the pixels 02 are clearly distinguishable from each other. This minimum contrast depends on the design of the optical or visual system used and also on the identification feature concerned 01 at the time of data acquisition or image capture ambient lighting conditions dependent. The pixels 02 of the pixel pattern are preferably each formed in their geometric design as a rectangle, in particular as a square. An arrangement of the respective pixels chosen for the formation of the pixel pattern 02 represents a z. B. with the aid of a computing unit using mathematical algorithms encoded, in particular machine-readable information content. In the case exemplified by the 1 to 3 In the QR code a link to the website www.kba.com is coded.

In a further advantageous embodiment, the first identification element is designed as a visually readable or haptic detectable font. In this case, the font in particular has at least one alphanumeric character. In yet another advantageous embodiment variant, at least one meaning carrier belonging to the code in the arrangement is designed as a pictogram or as an ideogram.

In a first operating state of the identification feature 01 the first identification element is visually recognizable by an irradiation of the surface having the identification elements with visible light and the second identification element is not visually recognizable. In a second operating state of the identification feature 01 is by irradiation of the identification elements having surface with a different from the first operating state electromagnetic radiation from the pigments random structure formed or formed from particles of at least one dye random structure of the second identification element, which within the same defined limited area as the first identification element is arranged on the object, visually recognizable. The random structure of the second identification element formed either from pigments or particles of the at least one dye preferably represents a second machine-readable information content. If the random structure of the second identification element formed either from pigments of a colorant or from particles of the at least one dye forms a second machine-readable information content, this becomes Information content preferably by means of a computing unit z. B. determined by a gray value determination or another threshold value evaluation with regard to the number and / or intensity of the pigments or particles concerned or with respect to the area filled or claimed by them in the first identification element. The respective information content of the first and / or second identification element is preferably in each case omnidirectionally readable.

As the 2 by way of example, the second identification element is one of pigments 03 or the random structure formed of at least one dye, wherein the pigments 03 or the at least one dye formed random structure of the second identification element only due to a by irradiation of electromagnetic energy having a wavelength z. B. from the UV-triggered optical change for a viewer in the visual field is recognizable and photographically mapped. For the optical perception of the second identification element so it requires an excitation, which takes place in the form of an energy supply, this energy is of an electromagnetic nature and preferably originates from a radiation whose respective wavelength z. B. is in the UV range. Basically, an emission spectrum of the radiation that is in the second operating state of the identification feature closes 01 into which the surface having the identification elements, the wavelength of at least one absorption line of the pigments or the particles of the at least one dye of the second identification element, wherein the radiant energy absorbed by the relevant pigment or the relevant particles of the dye that pigment or particles of the dye causes emission of electromagnetic radiation in the spectrum of visible light. In a preferred embodiment, the radiation energy is in the second operating state of the identification feature 01 in the surface having the identification elements radiated electromagnetic radiation at least 1.59 eV.

The pigments 03 or the particles of the at least one dye of the second identification element are preferably contained in a printing technology for the production of the first identification element, that is used here for printing, for example, the QR code ink, wherein at least a subset of the pixels 02 of the first identification element forming pixel pattern are formed from this ink or ink concerned. The first identification element and the second identification element are each z. B. in a pressure-form-bonded printing process, preferably in an offset printing process or in a gravure printing process or in a high-pressure process, or in a pressure-formless, ie direct printing process, for. Example, in an inkjet printing process or in an aerosol jet printing process on the object, that is arranged on the surface or applied to the article. The object on whose surface the identification feature 01 is formed, z. B. a substrate on which by means of a printing press several identification features 01 in a printing process z. B. be formed in a benefit. The substrate is z. B. formed as a web or as a sheet, the printing material z. B. made of paper or a plastic film or of a metal foil or of a textile. In another embodiment, the identification feature 01 formed directly and directly on the surface of the article by means of a printing process, the object z. B. as a package, in particular as a hollow body, for. B. as a (glass) bottle or as a (tin) can or as a plastic container, or as a salable product such as. B. is made of a plastic or of a ceramic or of a metal or wood. In the case of several identifiers applied to the substrate 01 These are separated after their pressure. The respective, z. B. each formed as a label individual identification features 01 are then available to be applied to another object or product whose identity and / or authenticity is to be subjected to a test at a later date on the basis of the relevant identification feature. That as one of pigments 03 or the second identification element formed of the random structure formed of at least one dye, as well as the respective one to the same identification feature 01 belonging first identification element for the multiple printed on the substrate in a same production process identification features 01 each same or different, ie be formed individually.

In a preferred embodiment, the pigments contained in the printing ink or ink are used to form the random structure 03 a core with a carrier and with either a fluorescent material or with a phosphorescent material, wherein the core preferably has a substantially spherical shape. In this case, a shell surrounding the core is provided, wherein the shell contains photochromic material with which a radiation emitted by the fluorescent material or the phosphorescent material is attenuated or at least attenuatable. The pigments used to form the random structure 03 then correspond to z. B. the in WO 2007/005354 A2 described embodiment.

Based on the above, a method is proposed in which an identification feature with a plurality of within a defined limited area on or on the object arranged identification elements is used to identify the object and / or to verify its authenticity, wherein in a first operating state of the identification feature irradiation of the surface having the identification elements with visible light a first identification element is visually recognizable and a second identification element is visually not recognizable, wherein the second identification element is formed as an integral part of the first identification element as a formed from pigments or particles of at least one dye random structure, wherein in a second operating state of the identification feature by irradiating the surface having the identification elements with one of the first Betriebszu was different electromagnetic radiation excited the random structure of the second identification element forming pigments or particles of the at least one dye for spontaneous emission and fluorescence or phosphorescence and visually recognizable. It is at a first location, eg. B. at the production of the relevant identification feature with a first data acquisition device in a first lighting situation in which the random structure of the second identification element is visually recognizable, the identification feature a single first image or a sequence of first images is detected, wherein the respective detected first image in shape digitized image data or a first information decoded from the respective detected first image are respectively stored in a first memory, wherein at a second, different from the first location with a second data acquisition device again in an illumination situation in which the random structure of the second identification element is visually recognizable in that a single second image or a sequence of second images which is preferably identical or at least comparable with respect to the illumination situations is detected by the same identification feature, wherein the respective detected second image in the form of digitized image data or a second information decoded from the respective second image are respectively stored in a second memory, wherein the first memory and the second memory connected to each other after a second place request for data exchange via a communication link in which, after the data transmission, the image data and / or the decoded information of the respective first image stored in the first memory of the identification feature arranged on or on the object and the image data and / or the decoded information of the respective second image thereof on or on this object arranged identification feature can be compared with each other with the aid of a computing unit, which is checked by means of the comparison, the identity and / or the authenticity of the object. The respective sequences exist z. B. from three or more images that are detected in particular in different lighting situations, with a first figure z. B. under normal daylight conditions with light in the wavelength range of 380 nm to 790 nm and a second image during irradiation of the identification feature with radiation from the IR or UV range and a third image after completion of the irradiation of the identification feature with the radiation IR or UV range. The respective sequences for the first image and for the second image preferably each have an equal number of images.

The first preferably non-contact digital data acquisition device and the second preferably non-contact digital data acquisition device are z. B. each a scanner or as a camera, in particular as a digital camera formed. The detection of the first image and / or the detection of the second image take place for. Using a code reader designed as an application program, e.g. B. a QR code reader or a program for automated text recognition or optical character recognition. The first memory and / or the second memory are z. B. each formed as a database in which the respective image is stored digitized in each case in the form of digitized image data and / or in each case one of the detected image concerned decoded information.

The respective mapping and / or decoding takes place temporally before the object z. From a supplier, who may also be the manufacturer of the article in question, to a user is delivered, so z. B. at a time in the manufacture of this article or in the application of the identification feature 01 on or on the object or product concerned. At another, later time, the user detects, using the irradiation of electromagnetic energy with a wavelength z. B. from the UV region in the second identification element, the respective second image of the identification feature 01 , wherein the image data from the respective second image and / or its decoded information are stored at least in the short term. For identification of the identification feature 01 carrying object and / or to check the authenticity of this object then the image data of the respective stored first image of the object arranged on the identification feature 01 and the image data of the detected respective second image of the identification feature disposed on that article 01 preferably in a computing unit z. B. compared with methods of image processing or pattern recognition and checked for conformity. Alternatively or additionally, the first information decoded from the detected respective first image and the second information decoded from the acquired respective second image are preferably compared with one another in the arithmetic unit and checked for conformity.

For a given and / or insufficient and / or missing match of the stored respective first image of the identification feature disposed on or on the article 01 with the detected respective second image of the identification feature arranged on or on this object 01 is generated by the comparison executing arithmetic unit a message relating to the comparison result to the user and / or to the supplier or the manufacturer of this object and / or z. B. optically displayed on a display or acoustically. In this case, the comparison of the stored respective first image of the object arranged on the identification feature 01 with the detected respective second image of the identification feature arranged on this article 01 ie, the previously described comparison of their respective digitally present image data or the respective decoded information, in a preferably mobile communication device, for. B. running in a smartphone, which nowadays usually each have a sufficiently powerful computing unit.

In another embodiment variant, the respective captured second image of the identification feature arranged on or on the object in question is 01 from the second data acquisition device via a preferably wireless communication link, e.g. B. via the Internet or a mobile phone connection, to a z. B. from the supplier or manufacturer of the object or operated for him stationary computer, z. B. transmit a network server. The transmission of the image data or the decoded information, in particular of the respective captured second image of the identification feature arranged on or on this object 01 z. B. to the stationary computer and / or a transfer of the result of the comparison message z. B. from the stationary computer in particular to the user and / or to the supplier or manufacturer of the subject matter and / or a transfer of the result of the comparison result z. B. by the user in particular to the stationary computer and / or to the supplier or manufacturer of the object in question is preferably encrypted in each case.

In a particularly preferred embodiment of the invention are in an amount of z. B. in a same production process printed identification features 01 for all identification features belonging to this set 01 their respective first identification elements each formed the same, ie they are all encoded with the same information, whereas the respective, to a specific identification feature 01 belonging second identification element is formed differently from the other belonging to this amount of second identification elements. This means that in a certain, z. B. in a same production process, in particular produced with a printing machine set of identification features 01 these identifiers 01 only by their each formed from pigments or the at least one dye random structure, which in each identification feature 01 each forms the second identification element, different from each other, but just because of this difference are also clearly identifiable. The relevant random structure is z. B. by an admixture of phosphor pigments or other luminescent or at least reflective or polarizing particles in the printing ink or ink to be printed and a stochastic distribution of these pigments or particles in the ink or ink produced, wherein the respective pigments or particles in relation to the surface of respective pixels z. B. the pixel pattern of the first identification element are each small. In an alternative embodiment, in an amount of z. B. in a same production process printed identification features 01 not only the respective second identification elements, but additionally also at least a subset of the respective first identification elements may each be formed individually by the relevant first identification elements in the relevant subset or all first identification elements of this set of identification features 01 each with a different from other identification features 01 this amount of distinctive information is encoded.

It can be provided that already z. B. at the end of a production line for producing a certain amount of identification features 01 from these identification features 01 in the relevant, z. B. as a printing machine formed production machine continuously according to the production progress for the production of this set of identification features 01 of each completed identification 01 with a non-contact digital data acquisition device, eg. B. with a scanner or with a camera, recorded at least a first image and z. B. in the form of digital image data in a first memory, in particular stored in a database, this at least a first image of the relevant identification feature 01 in each case only the first identification element or respectively the first identification element of which is depicted together with its second identification element. To execute the mapping of the relevant identification feature 01 in the relevant, z. B. formed as a printing machine production machine or processing machine, a lighting device with at least one light source of a semiconductor material, for. B. a LED or laser illumination device, and / or a scanner or a semiconductor camera with a CCD image sensor or a CMOS image sensor used. Alternatively, a lighting device may be used with at least one gas discharge tube, for. B. with a xenon filled flash tube. The production machine or processing machine can also be designed as a packaging machine or as a bottling plant or as a packaging machine. The first image is preferably without the use of a polarizing filter or a color filter or another of the relevant identification feature 01 remitting light manipulating accessory detected.

In the first lighting situation present at the first location and in the second lighting situation existing at the second location, in each case an electromagnetic radiation is used which is at least partially absorbed by the pigments or the particles of the at least one dye of the random structure. The electromagnetic radiation absorbing pigments or particles of the at least one dye of the random structure are excited by the at least partial absorption of the relevant electromagnetic radiation at least to a visually detectable luminescence, preferably also to fluorescence or phosphorescence, wherein the first image and the second image of the respective data acquisition device each detected during the luminescence of the pigments or the particles of the at least one dye of the random structure.

It is advantageous to be formed in a printing process identification features 01 of the type described above with a z. B. form as a sheet-fed press or as a web-fed printing press. This printing machine preferably has at least one printing device that prints in an inkjet printing method, this printing device having the relevant identification feature 01 by applying each of the pigments 03 or forming the particles of the at least one dye of the second identification element containing ink or ink on the surface of the object in question. This printing press has a control unit that controls the printing process carried out by the printing press, and preferably a plurality of drives and / or adjusting elements, wherein the drives and / or adjusting elements of the control unit z. B. depending on particular in this printing machine z. B. sensory detected or programmatically, z. B. are controlled by a production planning system parameters. The control unit and z. As the controlled by her drives and / or actuators are preferably in a particular digital network, eg. B. in a bus system at least in terms of data technology, wherein the drives and / or actuators are controlled by the control unit by a data communication over the network, in particular depending on sensory in this printing machine or programmed by program parameters. It is advantageous, even the relevant identification feature 01 forming printing device to connect to this network and the respective identification feature 01 related data over this network e.g. B. controlled by the control unit to communicate. In the printing machine is preferably connected to the network, z. B. arranged as a camera data acquisition device, with this data acquisition device of the identification feature 01 at least one image is detected, wherein the at least one acquired image in the form of digitized image data or an information decoded from the at least one acquired image information is stored in each case in a preferably connected to the network memory. The image data stored in the memory or the decoded information stored there are preferably only communicated via the network after a request triggered outside the printing press.

In an advantageous embodiment, the data acquisition device arranged in the printing press is used by the respective identification feature 01 detects a sequence of several images in a fixed period of time, wherein at least a part of these images is acquired under different lighting situations, wherein the images belonging to the same sequence and recorded under different lighting situations are respectively stored in the memory. It is particularly advantageous from the respective identification feature printed in each case with the printing device, preferably in an inkjet printing process 01 in each case at least three images to be detected with the data acquisition device arranged in the printing machine, wherein a first image only the z. B. formed as a QR code first identification element, because in the first lighting situation, the random structure having the second identification element z. B. under normal daylight conditions, that is not visually detectable or inconceivable especially when einstrahlendem light in the wavelength range between 380 nm to 790 nm. In the second lighting situation is by the same identification feature 01 or the same identification features 01 in each case a second image is recorded with the data acquisition device arranged in the printing machine, wherein in this second illumination situation the respective identification features 01 are each irradiated with electromagnetic energy of a certain wavelength, so that the random structure having the second identification element is recognizable together with the first identification element in the visual field and can be detected by the data acquisition device, in particular by a camera can be imaged, wherein the required electromagnetic energy z. B. is provided by a flash unit. In the third lighting situation, the irradiation of the respective identification features 01 each terminated with electromagnetic energy of a certain wavelength for visualization of the random structure having the second identification element and it is from the same identification feature 01 or the same identification features 01 with the arranged in the printing machine data acquisition device in each case a third image detected, wherein now the random structure having second identification element due to spontaneous emission, fluorescence or - if the process is delayed in time and / or much longer stops - of phosphorescence especially in the visual field recognizable is and can be detected by the data acquisition device. This sequence of at least three each from the same identification feature 01 or the same identification features 01 each captured with the data acquisition device arranged in the printing machine is z. B. evaluable by the control unit to the effect whether the relevant identification feature 01 or the respective identification features 01 properly created with the function of a security feature, ie has been printed or are, creating a test or production control or quality control of the respective identification features 01 is still running inside the printing press. The result of this test or production control or quality control or the respective sequence of images of the same identification feature 01 is z. B. stored in the preferably connected to the network memory.

In accordance with what has been described above, a method for the production control of identification features printed with a printing machine on a printing material or object can be carried out, wherein the identification features 01 a first identification element that can be visually detected under daylight conditions and a second identification element that can not be visually detected under daylight conditions, the second identification element only being activated by an irradiation of the identification feature 01 is visually detectable with electromagnetic energy of a certain wavelength that this radiated energy is at least partially absorbed by pigments of a colorant or particles of a dye of the second identification element and excited these pigments or these particles of the dye to a visually detectable spontaneous emission and fluorescence or phosphorescence be in the printing machine with a data collection device arranged in it from each printed with a printing device of this printing machine identification features 01 in each case a sequence with at least three images is detected, wherein the belonging to the respective sequence first image of the identification feature 01 only images the first identification element which can be visually detected under daylight conditions, wherein the second image of the identification feature belonging to the respective sequence 01 the first identification element, together with the second identification element emitting spontaneously under irradiation with electromagnetic energy of a specific wavelength, images the third image of the identification feature belonging to the respective sequence 01 the first identification element, together with the second identification element which fluoresces or phosphorescences after the irradiation with electromagnetic energy of a specific wavelength, is evaluated by the control unit to determine whether the identification feature in question is at least three images 01 having under daylight conditions visually unrecognizable, by irradiation with electromagnetic energy of certain wavelength spontaneously emitting and fluorescent after completion of this irradiation or phosphorescent second identification element. Preferably, the printing device of the printing press prints the respective identification features 01 , the z. B. are each formed as a QR code, each in an inkjet printing process. The second identification element is designed in particular as a random structure contained in the first identification element. The pigments of the colorant or particles of the dye used in each case for the second identification element are advantageously introduced in each case by an agitator and / or in an ultrasonic water bath and / or by means of an ultrasonic atomizer into an ink or ink used in each case for printing the first identification element. The pigments used for the second identification element of the colorant or particles of the dye are generally introduced in each case in a mass fraction of less than 5%, in particular up to at most 2% in the printing ink or ink used for printing the first identification element. For the second identification element, in particular those pigments of the colorant or those particles of the dye are used, each having a core with a fluorescent material or with a phosphorescent material and each one surrounding the core shell of a photochromic and / or a fluorescent or a phosphorescent material exhibit. The pigments correspond z. B. the in WO 2007/005354 A2 described embodiment. The shell, ie the surface of the pigments consists z. From a chitosan alginate or from a cellulose or from an ethylcellulose or from a gelatin or a gum arabic or from a melamine-aldehyde resin or from a melamine-formaldehyde resin or from a melamine-urea-formaldehyde resin or of nylon or of phenol formaldehyde or of polyacrylonitrile or of polyamide or of a polyelectrolyte complex or of a polyethylene or of a polyethylene glycol or of a poly-L-lysine or of a polylactide or of a polylysine or of an alginate or of a polynucleotide or of a Polypeptide or from a polyphosphazene or from a polypropylene or from a polysaccharide or from polystyrene or from a urea-formaldehyde resin. The time required for the spontaneous emission of the second identification element electromagnetic energy of certain wavelength is preferably from a z. B. emitted by the control unit controlled flash unit.

The pigments used for the second identification element of the colorant or particles of the dye preferably have a length extension in the range between 0.5 .mu.m and 10 .mu.m. The pigments used for the ink or the ink of the first identification element of the colorant or particles of the dye are each dispersed in a first dispersant, d. H. the pigments of the colorant or the particles of the dye form in each case a first heterogeneous composition in conjunction with the first dispersant, and the pigments used for the second identification element of the colorant or particles of the dye are each dispersed in a second dispersant to form a second heterogeneous composition , wherein preferably the first dispersant and the second dispersant differ from each other, so that different dispersants are used for the first identification element and for the second identification element, wherein between these two dispersants preferably repulsion, d. H. there is a rejection. The use of different dispersants for the first identification element and for the second identification element promote coagulation of the pigments used for the second identification element of the colorant or particles of the dye, d. H. a concentration of these pigments of the colorant or particles of the dye and thus a repeal of their finely divided state in the printed image generated in each case with the printing device.

For better printability of the ink or ink used in an inkjet printing process, this ink or ink at 23 ° C, a conductivity preferably in the range of 900 .mu.S / cm to 2200 μS / cm, in particular between 1000 μS / cm to 1,900 μS / cm. The conductivity of the ink or ink used is z. B. by a supply of additives, preferably by salts and / or polymers, for. B. increased by polymer salts. The additives may be in the form of z. B. a solid and / or a solution and / or a dispersion of the ink or ink used. Alternatively or additionally, in the printing ink or ink at least one conductive salt z. B. from the group of alkali metal salts or ammonium salts, wherein the conductive salt z. B. as ammonium sulfate or as ammonium chloride or as ammonium bromide or as magnesium sulfate or as sodium and potassium sulfate or as sodium and potassium chloride or as tetra-n-butylammonium bromide or as tetra-n-butylammoniumtetrafluoroborat or as tetra-n-butylammoniumhexafluorophosphat or as lithium hexafluorophosphate is. The viscosity of this ink or ink is in each case at 25 ° C for a CIJ printing process (CIJ = continuous ink jet) z. B. 2.5 mPa s to 6 mPa s or for a piezoelectric printing z. 3 cPa s to 8 cPa s. A density of the pigments used in the ink or dye of the dye or dye is in the range between 0.6 kg / m ³ and 1.3 kg / m ³ , preferably between 0.8 kg / m ³ and 1.0 kg / m ³ . When using a water-based ink or ink, the upper values of said ranges are preferred.

This results z. B. an identification feature with at least two arranged in a defined limited area identification elements for identifying an object, wherein by a Irradiation of the visible light elements having the identification elements of the identification feature whose first identification element is visually recognizable and whose second identification element is not visually recognizable, wherein the first identification element is formed from a printing ink or an ink, wherein the second identification element is one of pigments of a colorant formed random structure or as a formed of particles of at least one dye random structure, wherein the random structure of the second identification element is formed as an integral part of the ink or the ink of the first identification element. In this case, the ink or ink at 23 ° C has a conductivity in the range of 900 .mu.S / cm to 2,200 .mu.S / cm and / or in the ink or in the ink of the first identification element is at least one polymer and / or as an additive Conducting salt at least one alkali metal salt or an ammonium salt. A conducting salt is a salt which, during electrolysis, undertakes a transport of electrical charges and / or reduces the ohmic resistance of the solution in a solution. In this case, the random structure of the second identification element forming pigments or particles of the at least one dye have a density z. B. in the range between 0.6 kg / m ³ and 1.3 kg / m ³ . The viscosity of the ink or ink at 25 ° C is z. In the range between 2.5 mPa s and 6 mPa s or in the range between 3 cPa s and 8 cPa s. In a preferred embodiment, the pigments or particles of the at least one dye forming the random structure of the second identification element have a spherical surface and those pigments of a colorant or those particles of at least one dye, each containing as colorant in the printing ink or ink forming the first identification element are edged or spherical. Further, the pigments of the colorant or the particles of the dye of the ink or the ink of the first identification element are each dispersed in a first dispersant and the pigments of the colorant or the particles of the dye of the second identification element are each dispersed in a second dispersant, wherein the first Dispersant and the second dispersant preferably differ materially from each other. The pigments of the colorant forming the random structure of the second identification element or the particles of the at least one dye preferably have an incident light diffusely reflecting surface. The random structure of the second identification element forming pigments of the colorant or the particles of the at least one dye have z. B. a length extension in the range between 0.5 .mu.m and 10 .mu.m. The printing ink or the ink of the first identification element is preferably applied in a layer thickness in the range of 0.3 μm to 10 μm on a surface of the object to be identified. The pigments of the colorant or the particles of the dye each of the printing ink or the ink of the first identification element are made of an organic or of an inorganic or of a synthetic crystalline powder or in particular of carbon black or of titanium (IV) oxide or of an aluminum bronze or formed from a brass bronze. The pigments of the colorant or the particles of the dye in each case by the printing ink or the ink of the first identification element are in a mass fraction z. B. between 12% and 18% in the relevant of the ink or ink and / or each of the random structure of the second identification element forming pigments of the colorant or the particles of the dye are each in a mass fraction, in particular less than 5%, preferably less than 2% contained in the relevant ink or ink of the first identification element.

An identification feature also results with at least two identification elements arranged in a defined limited area for identifying an object, whereby the first identification element is visually recognizable by irradiation of the surface having the identification elements of the identification feature with visible light and its second identification element is not visually recognizable, wherein the first identification element is formed from a printing ink or from an ink, wherein the second identification element is formed as a random structure formed from pigments of a colorant or as a random structure formed from particles of at least one dye, wherein the random structure of the second identification element as an integral part of Printing ink or the ink of the first identification element is formed, wherein the on a surface of the object to be identified in a For the lattice-shaped arrangement of pixels applied ink or ink of the first identification element has a layer thickness in the range of 0.3 .mu.m to 10 .mu.m, wherein the random structure of the second identification element forming pigments of the colorant or the particles of the at least one dye by coagulation, ie by a Concentrate a multiple adjacent pixels of the graphic, in particular Rastergrafik comprehensive flat structure form ( 3 ). The raster graphics consists of a grid-like arrangement of the pixels, this arrangement forming an image in the form of computer-readable data. This arrangement has at least two groups of pixels between which there is a visually perceivable contrast. The pigments of the colorant forming the random structure of the second identification element or the particles of the at least one dye which, by coagulation, form a planar structure comprising a plurality of adjacent pixels of the raster graphic ( 3 ) are each formed in pixels of the same brightness, z. B. in each case with a compared to other pixels same raster graphics dark ink or ink formed pixels. In this case, the pigments of the colorant forming the random structure of the second identification element or the particles of the at least one dye have a length extension in the range between 0.5 μm and 10 μm. In a very advantageous manner, the pigments of the colorant forming the random structure of the second identification element or the particles of the at least one dye exhibit spontaneous emission of visually detectable light and / or fluorescence and / or phosphorescence by an incident electromagnetic radiation of the type described above. In addition, the identification feature may be formed with any of the physical and / or material features described above.

Accordingly, an article with an identification feature arranged for its identification can be formed, wherein the identification feature has at least two identification elements in a defined limited area, wherein the first identification element is formed from a printing ink or an ink, wherein the second identification element is one of pigments The random structure of the second identification element is formed as an integral part of the ink or the ink of the first identification element, wherein the ink or the ink of the first identification element in a layer thickness is applied in the range of 0.3 μm to 10 μm on a surface of the object to be identified, which forms the random structure of the second identification element Nden pigments of the colorant or the particles of the at least one dye have an incident electromagnetic radiation diffusely reflecting surface. This item is z. B. as a substrate made of paper or a plastic film or of a metal foil or of a textile or as a hollow body or as a bottle or as a can or as a product made of a plastic or of a ceramic or of a metal or wood , The pigments of the colorant or the particles of the dye each of the printing ink or the ink of the first identification element are made of an organic or of an inorganic or of a synthetic crystalline powder or of carbon black or of titanium (IV) oxide or of an aluminum bronze or formed of a brass bronze and / or the random structure of the second identification element forming pigments of the colorant or the particles of the at least one dye have a surface of a chitosan Algnat or of a cellulose or of an ethylcellulose or of a gelatin or a gum arabic or a melamine-aldehyde resin or a melamine-formaldehyde resin or a melamine-urea-formaldehyde resin or nylon or phenol-formaldehyde or polyacrylonitrile or polyamide or a polyelectrolyte complex or a polyethylene or a polyethylene glycol or from a poly LL ysin or from a polylactide or from a polylysine or from an alginate or from a polynucleotide or from a polypeptide or from a polyphosphazene or from a polypropylene or from a polysaccharide or from polystyrene or from a urea-formaldehyde resin. It can be provided that, by irradiating the surface of the identification elements of the identification feature with visible light in a wavelength range from 380 nm to 790 nm, its first identification element is visually recognizable and its second identification element can not be visually recognized.

Alternatively, there is also an article with an identification feature arranged for its identification, wherein the identification feature has at least two identification elements in a defined limited area, wherein the first identification element is formed from a printing ink or an ink, wherein the second identification element as one of pigments of a The random structure of the second identification element is formed as an integral part of the printing ink or the ink of the first identification element, wherein the ink or ink applied to a surface of the object to be identified is formed colorant formed random structure or as a random structure formed of particles of at least one dye of the first identification element is preferably applied in a raster graphic consisting of a lattice-like arrangement of pixels, wherein the random structure de Coagulation of the second identification element-forming pigments of the colorant or the particles of the at least one dye form a planar structure comprising a plurality of adjacent pixels of the raster graphic ( 3 ). In this case, the random structure of the second identification element forming pigments of the colorant or the particles of the at least one dye by an incident electromagnetic radiation of a certain wavelength z. Example, a spontaneous emission of visually detectable light and / or fluorescence and / or phosphorescence, wherein the random structure of the second identification element forming pigments of the colorant or the particles of at least one dye their spontaneous emission of visually detectable light and / or fluorescence and / or phosphorescence by an incident electromagnetic radiation having a wavelength in particular from the IR range or from the UV range. In addition, the identification feature of the article may be formed with one or more of the physical and / or physical features described above.

There is also provided a method of checking the identity and / or authenticity of an article using an identification feature with a random structure formed from pigments of a colorant or from particles of at least one dye, the random structure forming an integral part of one on a surface of the article Subject matter applied ink or ink is formed, wherein the random structure forming pigments of the colorant or the particles of the at least one dye by irradiation of the identification feature with an electromagnetic radiation from the IR range or the UV range to a spontaneous emission and fluorescence or Phosphorescence excited and visually recognizable, wherein for checking the identity and / or authenticity of the object with a data acquisition device of the identification feature during the irradiation of the identification feature with the electromagnetic beam a single first image or a sequence of first images is detected from the IR region or the UV region, and wherein the same data acquisition device of the relevant identification feature after termination of the irradiation of the identification feature with the electromagnetic radiation from the IR region or the UV A single second image or a sequence of second images is detected, wherein it is checked by means of a computing unit comparing the respective first and second images, whether the random structure forming pigments of the colorant or the particles of the at least one dye fluoresce or phosphorate, wherein the fluorescence or phosphorescence detected by the arithmetic unit of the random structure pigments of the colorant or particles of the at least one dye, the identity and / or authenticity of the article is considered confirmed. The random structure is z. B. by irradiation of the identification feature with light in a wavelength range of 380 nm to 790 nm visually unrecognizable. The identification feature is arranged on or on the object in a printing-form-linked printing method or in a printing-form-free printing method. As an object z. B. used as a web or as a sheet printing material or a package or a hollow body or a bottle or a can or a plastic container used. The identification feature is preferably arranged on or on the object in a printing machine or in a packaging machine or in a filling installation or in a finishing machine. The respective images of the identification feature are respectively detected in each case with a data acquisition device of a mobile communication device, wherein a camera of a mobile phone or a smartphone is preferably used as the data acquisition device. The pigments forming the random structure of the colorant or the particles of the at least one dye form a planar structure by coagulation, wherein the planar structure is greater than an optical resolution of the data acquisition device used for the images. An information content of the random structure is determined in particular by means of a computing unit by means of a gray value determination or a threshold value evaluation with regard to the number and / or the intensity of the relevant pigments or particles or with regard to the area claimed by them. The identification feature of the article may in turn be formed with one or more of the physical and / or material features described above.

LIST OF REFERENCE NUMBERS

01

 identification feature

02

 pixel

03

 pigment

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2007/017049 A1 [0024, 0024]
• EP 2062960 A1 [0026]
• WO 00/059731 A1 [0050, 0052]
• WO 2012/083469 A1 [0050, 0054]
• WO 2013/054290 A1 [0057]
• WO 2007/005354 A2 [0057, 0057, 0097, 0108]
• WO 2015/114540 A2 [0058]
• EP 2637145 A1 [0059]
• WO 2004/070667 A2 [0060]
• WO 2006/078220 A1 [0062]
• US 2001/0010333 A1 [0063]
• WO 2007/131043 A2 [0064]
• WO 2013/144645 A1 [0065]
• WO 2010/023243 A1 [0066]
• DE 2829778 A1 [0067]
• DE 19611383 A1 [0068]
• WO 2013/034471 Al [0069]
• EP 2698404 A1 [0070]
• WO 2013/060831 A2 [0071]
• WO 2006/065978 A2 [0074]

Cited non-patent literature

• DIN 55943: 2001-10 [0027]
• DIN 55943 [0027]
• http://iopscience.iop.org/0957-4484/23/39/395201/cites [0073]
• Jeevan M Meruga et al., Published by the Institute of Physics (IOP) at the University of South Dakota and the South Dakota School of Mines and Technology on September 11, 2006, "Security Printing of Covert Quick Response Codes Using Upconverting Nanoparticle Inks" 2012 in IOP Publishing's Journal Nanotechnology, Volume 23, No. 395201, doi: 10.1088 / 0957-4484 / 23/39/395201 [0073]
• Standard ISO / IEC 16022 [0076]
• ISO / IEC 18004 [0076]
• Standard ISO / IEC 24778 [0076]

Claims (10)

An article with an identification feature arranged for its identification, wherein the identification feature has at least two identification elements in a defined limited area, wherein the first identification element is formed from a printing ink or an ink, wherein the second identification element as a random structure formed from pigments of a colorant or as a random structure formed of particles of at least one dye, wherein the random structure of the second identification element is formed as an integral part of the ink or the ink of the first identification element, wherein the ink or ink of the first identification element applied to a surface of the object to be identified in a grid-shaped arrangement of pixels is applied, wherein the random structure of the second identification element forming pigments of the colorant or the P Coagulate the article of at least one dye form a planar structure comprising a plurality of adjacent pixels of the grid-like arrangement. An article according to claim 1, characterized in that this article as a substrate made of paper or a plastic film or a metal foil or a textile or as a hollow body or as a bottle or as a can or as a product made of a plastic or from a Ceramic or made of a metal or wood. The article of claim 1 or 2, characterized in that the pigments of the random structure of the second identification element forming pigments of the colorant or the particles of the at least one dye have an incident electromagnetic radiation diffusely reflecting surface. The article of claim 1 or 2 or 3, characterized in that the random structure of the second identification element forming pigments of the colorant or the particles of the at least one dye by an incident electromagnetic radiation spontaneous emission of visually detectable light and / or fluorescence and / or phosphorescence , An article according to claim 4, characterized in that the pigments of the colorant forming the random structure of the second identification element or the particles of the at least one dye their spontaneous emission of visually detectable light and / or fluorescence and / or phosphorescence by an incident electromagnetic radiation having a wavelength of the IR range or from the UV range. Article according to claim 1 or 2 or 3 or 4 or 5, characterized in that by irradiating the identification elements of the identification feature having surface area with light in a wavelength range of 380 nm to 790 nm whose first identification element is visually recognizable and the second identification element visually not is recognizable. An article according to claim 1 or 2 or 3 or 4 or 5 or 6, characterized in that the grid-like arrangement of the pixels forms an image in the form of computer-readable data. An article according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7, characterized in that the grid-like arrangement of the pixels is formed as a QR code. An article according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8, characterized in that the grid-shaped arrangement comprises at least two types of pixels, between which there is a visually perceptible contrast. An article according to claim 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9, characterized in that the pigments of the colorant forming the random structure of the second identification element or the particles of the at least one dye coagulate by a plurality of adjacent pixels Form the lattice-shaped arrangement comprehensive planar structure, each formed in pixels of the same brightness.

Images