Patent Description:
Optically variable pigments may give unique effects. When applied in an ink or printed on banknotes or other valuable documents, they constitute an effective protection against scanning, photocopying, or counterfeiting. A product comprising an element printed with an optically variable ink is easy to be recognized, but, because of limited access to raw materials, it is difficult to produce and counterfeit.

There are many solutions enabling to mark valuable documents using an optically variable ink. A data carrier is known composed of many layers, wherein a layer with a locally applied and optically variable ink is situated on the external surface of the data carrier. In order to personalize, the optically variable ink is removed permanently using a laser, whereby a subsequent layer, that lies beneath, becomes visible. Both narrower elements, like letters or figures, as well as bigger signs may be removed. The optically variable ink may be applied onto a paper or polycarbonate substrate. The marking adopts the color of the exposed layer.

Another solution shows a valuable document, for example a banknote, having a lot of layers, including a marking layer comprising a mixture of various additives and/or pigments. The mixture contains components absorbing laser radiation as well as components that are transparent to laser radiation. The component that is transparent to laser radiation may contain optically variable pigments based on liquid crystals, whereas the component that absorbs the laser radiation is a component of the ink, the optical properties of which may be irreversibly changed by exposing to the laser radiation. Thus, it is possible that by irradiating with a laser, the absorbing layer will be removed within the irradiation area, whereas the layer, that is transparent to the given laser radiation and is situated above the absorbing layer, will be captured away therewith.

The main disadvantage of the solutions of this type available in the market today is that the marking process of an optically variable ink layer, for paper or polymer non-laminated substrates, is often performed by the total removal the ink layer. When, in turn, removing a layer of an optically variable ink totally, when carrying out the marking process of a laminated product, the structure of the document may be impaired or damaged.

Moreover, in known solutions the layer of an optically variable ink is not the only layer subjected to the marking process. This layer is accompanied by other layers, transparent or absorbing for the laser radiation, that are subjected to the marking process too. Furthermore, in known solutions, in a single ink layer that contains optically variable pigments, additionally, liquid crystal pigments are present - transparent to laser radiation. Moreover, the above described markings can not be performed after the lamination process of the layers of a security document.

Document <CIT> discloses a laminated security document.

There is no known, so far, process for marking optically variable inks containing fluorescent pigments and/or dyes, characterized by a change of optical properties both in the visible radiation and in the ultraviolet radiation, wherein, depending on the used laser radiation, one obtains an increase or a decrease of the fluorescence of the marked region.

Therefore, the aim of the invention is to change the visual perception of a securing element having the form of a laser marking printed with an optically variable ink or an optically variable ink with an addition of fluorescent pigments and/or dyes, using laser radiation, without total destruction of the ink layer within the marking region on the security document, the substrate of which may be made from paper, polyvinyl chloride, polycarbonate, polyester (PETG) or another polymer material. The used layer of the optically variable ink or the optically variable ink with the addition of fluorescent pigments and/or dyes, does not contain, for example, any liquid crystal pigments and constitutes a separate layer that may be subjected to a marking process with a perceivable visual effect when observing under the visible light as well as when observing under the ultraviolet light. Moreover, the aim of the invention is to deliver a method for marking a security document that makes it possible to perform the marking both before as well as after the lamination process.

These aims are achieved with a security document and a method, having features stated in the independent claims.

A laminated security document according to the invention has been defined in claim <NUM>.

The marking region is situated on a substrate or on a coating layer situated on the substrate.

Preferably, the ratio by weight of the optically variable pigments to the fluorescent pigments and/or dyes within the marking region is at least <NUM>:<NUM>, preferably <NUM>:<NUM>.

Preferably, the laser marking is recognizable by a visible decrease of the fluorescence intensity of the fluorescent pigments and/or dyes when illuminating the laser marking with the ultraviolet light. Preferably, for the laser marking, the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>. Moreover preferably, the laser marking is recognizable by a visible increase of the fluorescence intensity of the fluorescent pigments and/or dyes when illuminating the laser marking with the ultraviolet light. Preferably, for the laser marking, the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM> or <NUM>, or the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>.

Preferably, the laser marking is composed of at least two laser markings of different or the same intensities of the light emission from the fluorescent pigments and/or dyes under the ultraviolet light.

Moreover preferably, the security document comprises a lenticular element that is located on the surface of the coating layer, and the marking region is situated entirely or locally below the lenticular element within the structure of the coating layer.

Preferably, the substrate and/or the coating layer is made from polycarbonate or polyester or PVC, or derivatives thereof.

Moreover preferably, the security document comprises a second marking in the laminate region, in which there is no marking region. The laser marking is visually recognizable due to an irreversible change of interference properties of the layer of the printing ink caused by a laser beam, whereas the second marking is visually recognizable due to a local change of the color of the security document, caused by the same laser beam. Thereby, the second marking adopts a third color different than the marking region and/or the laser marking. The second marking constitutes a visual unity together with the laser marking.

A laminated security document, not according to the invention, with a securing element located locally or on the whole surface of the security document, at least one coating layer being deposited onto the securing element, comprises a marking region composed of at least one printing ink layer containing optically variable interference pigments and free of additives changing the absorption spectrum of the printing ink layer, the marking region comprising a laser marking applied by laser radiation, the laser marking being visually recognizable basing on an irreversible change of interference properties of the printing ink layer containing optically variable interference pigments and transformation, within the laser marking, of an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle, wherein for producing the laser marking the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>.

The security document comprises a lenticular element that is located on the surface of the coating layer, and the marking region is located entirely or locally below the lenticular element within the structure of the coating layer.

The substrate and/or the coating layer is made from polycarbonate or polyester or PCV, or derivatives thereof.

The security document comprises a second marking in the laminate region, in which there is no marking region. The laser marking is visually recognizable due to an irreversible change of interference properties of the printing ink layer caused by a laser beam, whereas the second marking is visually recognizable due to a local change of the color of the security document, caused by the same laser beam. Thereby, the second marking adopts a third color different than the marking region and/or the laser marking. The second marking constitutes a visual unity together with the laser marking.

Furthermore, the invention relates to a method according to claim <NUM>.

Preferably, when illuminating the laser marking with the ultraviolet light, a decrease of the fluorescence intensity of the fluorescent pigments and/or dyes is visible. For producing the laser marking, the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>.

Preferably, when illuminating the laser marking with the ultraviolet light, an increase of the fluorescence intensity of the fluorescent pigments and/or dyes is visible. For the laser marking, the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM> or <NUM> or the laser radiation is used of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>.

Preferably, while irradiating the marking region with a laser beam, a laser marking is produced composed of at least two laser markings demonstrating different or the same intensities of the light emission from the fluorescent pigments and/or dyes under the ultraviolet light.

Preferably, an additional step d) is possible, wherein a lenticular element is produced in the coating layer during the laminating step, that is located locally or entirely above the marking region.

Preferably, when irradiating the marking region with a laser beam, a laser marking is produced and, cumulatively, a second marking is produced in the laminate region during this irradiation step using the same laser beam of the same parameters. Alternatively, the operating parameters of the laser, producing the laser marking and the second marking in the laminate region, are different.

Not according to the invention, a method for producing a security document with a securing element comprises steps of:.

Not according to the invention, while irradiating the marking region with a laser beam a laser marking is produced and, cumulatively, a second marking is produced in the laminate region during this irradiation step using the same laser beam of the same parameters. Alternatively, the operating parameters of the laser, producing the laser marking and the second marking in the laminate region, are different.

The marking region is applied onto the substrate or a coating layer.

Not according to to the invention, an additional step d) is possible, wherein a lenticular element is produced in the coating layer during the laminating step, that is located locally or entirely above the marking region.

Not claimed by the invention is a securing element comprising a marking region composed of at least one printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes and free of additives changing the absorption spectrum of the printing ink layer on the security document placed on a laminated substrate, having features as described above. Also, the invention relates to a securing element comprising a marking region composed of at least one printing ink layer containing optically variable interference pigments and free of additives changing the absorption spectrum of the printing ink layer on the security document placed on a laminated substrate having features as described above.

The present invention will be more clear and more fully appreciated basing on the following detailed description read in reference to the drawings, in which:.

The following description presents examples of realizing a method, a security document, and a securing element comprising a marking region in the form of an optically variable ink containing an addition of fluorescent pigments and/or dyes or a pure optically variable ink layer, free of additives changing the absorption spectrum of the printing ink layer in order to adjust the absorption spectrum to the wavelength of the used laser, without which the marking would not be possible, and a laser marking, in which, after irradiating with laser radiation, the color changing effect is destroyed and the intensity of the fluorescence of the marking region and/or laser marking is changed, the method being possible to perform both before the lamination process as well as after the lamination process. However, it should be stressed that the described examples in no way are intended to limit the scope of the protection and are given merely to illustrate one of many possible applications of the present invention. The present invention is applicable everywhere where one needs to produce a marking in a layer of an optically variable ink or in a layer of an optically variable ink with fluorescent pigments and/or dyes on a non-laminated substrate as well as after the lamination process.

In one embodiment, a security document has a form and a format of a card, such as an ID card. In alternative embodiments, the security document may be another data carrier such as chip cards, smart cards, personal documents, driving license, checks, tickets as well as other valuable and security documents and data carriers being a safe medium for information storage.

The non-laminated substrate is a material free of external protective layers, for example, it may be a paper substrate, a paper-like substrate, and/or z paper-derivative materials, such as teslin, as well as any of polymer substrate, including polycarbonate (PC) and/or PVC (polyvinyl chloride) and/or polyester (e.g., polyethylene terephthalate (PET)), and/or polyolefins, e.g., polyetylene (PE), polypropylene (PP) and/or acrylonitrile and butadiene/styrene copolymer, ABS and/or polyuretane (PU) and/or polyether ether ketone (PEEK) (copolymer).

The laminated substrate and the coating layer in the sense of the present invention is a layer that is composed of polycarbonate (PC), polyvinyl chloride (PVC) and/or polyester (e.g., polyethylene terephthalate (PET) and, optionally, combinations thereof.

A security document <NUM> according to the invention, has various security features. The security features are elements that increase the safety against counterfeiting the security document. For example, a personalization <NUM> is applied onto the security document <NUM>, as a photograph of the owner of the security document <NUM>. Furthermore, personal data (not shown) of the owner of the security document <NUM> may be printed, preferably by means of laser printing or engraving performed in a layer of the security document <NUM> that is laser active or sensitive. Also, the security document <NUM> may comprise electronic components such as an RFID transponder, chip modules, antennae for dual-interface modules, or a hologram element. However, the above mentioned security features are not shown in the figures, because they do not constitute the subject matter of the present invention. The security document <NUM> comprises a securing element <NUM> comprising a marking region into which a laser marking has been introduced. The marking region may extend over the entire surface or on only a portion of the security document <NUM>. The marking region may adopt any form: an alphanumeric character, a microtext, a line, a geometrical shape, a bitmap picture, a geometrical form, a figure, a letter, a picture, or a combination thereof. Also, the laser marking may adopt any form: an alphanumeric character, a microtext, a line, a geometrical shape, a bitmap picture, a geometrical form, a figure, a letter, a picture, or a combination thereof. The marking region and the laser marking may be evaluated both visually as well as automatically. The visual evaluation is performed with the naked eye.

According to the present invention, a laser sensitive marking region is a layer of a material exhibiting an optically variable effect. This material is a printing ink containing optically variable interference pigments or containing optically variable pigments and an additive of fluorescent pigments and/or dyes.

The printing ink containing optically variable interference pigments, according to the present invention, is for example an optically variable ink such as SICPA OVI® Gold to Green, Magneta to Green, Green to Blue, Green to Magenta, Gold to Blue, SICPASTAR® Turquoise to Purple, Pink to Green, Blue to Purple, Lilac to Olive, an optically variable ink such as SICPA OVMI® Gold to Green, Magenta - Green, Green - Blue, and the Gold - Green ink based on a pigment from Zhuhai Qun Wang Technology Co. However, the present invention is not limited to these inks, but on the contrary, it may be realized with any printing ink containing optically variable interference pigments, free of additives changing the absorption spectrum of the binder of the printing ink layer in order to adjust the absorption spectrum to the wavelength of the used laser without which the marking would not be possible, or with a printing ink containing optically variable interference pigments with an addition of fluorescent pigments and/or dyes.

According to the present invention, optically variable pigments contained in the printing ink applied onto the marking region function independently and no other additives are needed that change the absorption spectrum of the printing ink layer, for example liquid crystal pigments or additional binding agents, for example based on polycarbonates or other thermoplastic polymers. Thus, it is possible to employ different optically variable inks or optically variable inks with an addition of fluorescent pigments and/or dyes, the media of which are various organic substances. When lamination is included, there is no need for the binding of the optically variable ink or the optically variable ink with an addition of fluorescent pigments and/or dyes to exhibit affinity to polycarbonate.

<FIG> shows a security document <NUM> according to the invention that has various security features. For example, a personalization <NUM> is applied onto the security document <NUM>, as a photograph of the owner of the security document <NUM>. The security document <NUM> comprises a securing element <NUM> comprising a marking region <NUM> into which a laser marking <NUM> has been introduced. The marking region <NUM> extends on a portion of the surface of the security document <NUM> as a geometrical shape - an ellipse. In this embodiment, the laser marking <NUM> shows alphanumeric characters.

<FIG> shows a diagram of the security document <NUM> in the laminated form, with the securing element before and after the marking process. <FIG> shows the security document <NUM> onto which a marking region <NUM> is deposited, by means of presently available printing techniques, as an optically variable ink layer, exhibiting an optically variable effect. The optically variable effect is based on a change of the printing color when observing at different angles. If one tilts the security document <NUM> changing the observation angle, this being shown in <FIG>, then a color change is visible in the marking region <NUM>. The state of the art knows a lot of color transitions of an optically variable ink, for example, green to blue, magenta to green, golden to green. However, colors of an optically variable ink layer and color transitions thereof are not the subject matter of the present invention. The marking is produced by irradiating the marking region <NUM> with laser radiation appropriately. Along with an increase of the laser radiation intensity, more and more fraction of an original color in the laser marking <NUM> is converted into another color. For example, the color may be silver or metallic. It is shown in <FIG>. After performing the marking process in the marking region <NUM>, the color of the optically variable ink layer in the marking region <NUM> has not been changed in this region as well as the color changing effect depending on the observation angle is intact. In turn, the laser marking <NUM> has been changed into another color demonstrating no change dependent on the observation angle, this being shown in <FIG>. When an optically variable ink with an addition of fluorescent pigments and/or dyes is used, then, when illuminating it with the ultraviolet light, for example in the range of <NUM>, <NUM>, or <NUM>, one can see also a security feature in the form of fluorescence of the marking region <NUM> and fluorescence of the laser marking <NUM>, wherein the laser marking <NUM> may demonstrate a decreased or increased emission of the fluorescent pigments and/or dyes relative to the intensity of the emission of the marking region <NUM>.

<FIG> shows the marking region <NUM> deposited on a non-laminated substrate <NUM>, i.e., a paper or polymer substrate of the security document <NUM>, for example banknote paper or a polycarbonate sheet. The marking region <NUM> is printed using one of the best currently available printing methods, for example screen printing, steel engraving, spraying, or pad printing.

The irradiation process of the laser marking <NUM> may be carried out in such a manner that the laser beam is directed directly onto the marking region <NUM> and affects the side on which the marking region <NUM> is located. In this way, the optically variable ink layer present in the marking region <NUM> is decolorized and its color changing effect is destroyed. During the laser irradiation, the laser marking <NUM> changes its interference properties and transforms from an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle, as shown in <FIG>. The said another color may be for example a metallic or the color silver. The marking region <NUM>, after irradiating with the laser radiation and producing the laser marking <NUM>, exhibits a uniform intact external structure of the marking region <NUM>. The thickness of the optically variable ink layer in the marking region <NUM> is not changed, as well as it is not damaged. Its thickness is from <NUM> to <NUM>, preferably from <NUM> to <NUM>.

The laser marking <NUM> is produced for example by means of a UV laser in the wavelength range from <NUM> to <NUM>, visible light lasers in the wavelength range <NUM> to <NUM>, infrared lasers of wavelengths from <NUM> to <NUM>, or a CO<NUM> laser of a wavelength <NUM>.

Onto a paper substrate having a thickness of <NUM> a marking region <NUM> of a thickness of <NUM> - <NUM> was deposited, by means of screen printing, in the form of an optically variable OVI® Magenta - Green ink layer available from SICPA and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible. The marking was produced with an ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM>, and the speed between <NUM> a <NUM>/s. Under the influence of the laser radiation in the ultraviolet range, a laser marking <NUM> is produced.

The vast majority of presently issued public documents and banknotes comprise security features exposed under UV radiation. An example of such a security features is fluorescence - and more precisely an emission of visible radiation resulting from illuminating with ultraviolet radiation. Therefore, according to another embodiment of the present invention, the marking region <NUM> contains, additionally, pigments and/or dyes having fluorescent properties.

The terms "pigments" and "dyes" refer to different substances. A pigment is an insoluble coloring substance having a form of finely ground solid matter, whereas a dye is a coloring substance, that may dissolve in a given medium. The terms "a pigment" and "a dye" refer not only to visible coloring, hence, according to the invention, they may be used for fluorescent substances.

The excitation of an optically variable ink containing pigments of fluorescent properties with the UV radiation of the appropriate wavelength range results in an emission of electromagnetic waves in visible range. For example, fluorescent inks may emit yellow light, green light, blue light, orange light, red light, and a combination thereof. Fluorescent inks are tested with UV lamps emitting light of a wavelength of <NUM>, <NUM>, and <NUM>.

According to the invention, a security document <NUM> is proposed with a securing element <NUM> located locally or on the whole surface of the non-laminated substrate <NUM>, comprising a marking region <NUM> composed of at least one printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes and free of additives changing the absorption spectrum of the printing ink layer, the marking region <NUM> having no other coating layers. The marking region <NUM> comprises a laser marking <NUM> applied by laser radiation, that is visually recognizable basing on an irreversible change of interference properties of the printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes and on a change, in the laser marking <NUM>, of an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle.

Research works of the Inventors devoted to the properties of an optically variable ink containing pigments and/or dyes of fluorescent properties have shown that, when performing the marking of the laser marking <NUM> in the marking region <NUM>, containing, in addition to optically variable pigments also pigments of fluorescent properties, as shown in <FIG>, with ultraviolet, visible, or infrared light, not only the color changing effect, depending on the observation angle of the laser marking <NUM>, may be lost, but also a change of the intensity of the light emission from the fluorescent pigments and/or dyes may occur. <FIG> illustrates this embodiment. According to the invention, a decrease as well as an increase of the intensity of the emission of the visible radiation may occur, after illuminating with the radiation in the range of <NUM>, <NUM>, or <NUM>.

In order to obtain said change of the light emission from the fluorescent pigments and/or dyes, the ratio by weight of the optically variable pigments to the fluorescent pigments and/or dyes in the marking region <NUM> should be at least <NUM>:<NUM>, preferably <NUM>:<NUM>.

Onto a polymer substrate having a thickness of <NUM>, a marking region <NUM> of a thickness of <NUM> - <NUM> was deposited, by means of screen printing, in the form of an optically variable OVI® Green - Magenta ink layer available from SICPA and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible, along with an addition of fluorescent pigments and/or dyes where the ratio by weight of the optically variable pigments to the fluorescent pigments and/or dyes is <NUM>:<NUM>. The marking was produced with the ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM> and the speed between <NUM> and <NUM>/s. Under the influence of the laser radiation in the ultraviolet range a laser marking <NUM> is produced exhibiting no optical variability, in favor of perception of a metallic color, and a decrease of the intensity of the emission of the visible radiation after illuminating with the radiation in the range of <NUM>, <NUM>, or <NUM>.

The laser marking <NUM>, according to the invention, demonstrates a decrease of the fluorescence intensity of the fluorescent pigments and/or dyes, if the laser radiation of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM> is used for the marking process.

Alternatively, according to the invention, the laser marking <NUM>, demonstrates an increase of the fluorescence intensity of the fluorescent pigments and/or dyes in the printing ink layer, if the marking is produced with the laser radiation of a wavelength in the range of:.

Onto a paper substrate having a thickness of <NUM>, a marking region <NUM> of a thickness of <NUM> - <NUM> was deposited, by means of screen printing, in the form of an optically variable SICPASTAR® blue - purple ink layer, available from SICPA, and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible, and containing an addition of fluorescent pigments and/or dyes (the ratio by weight of the OVI pigment to the fluorescent addition was <NUM>:<NUM>). The laser marking <NUM> was produced with a visible light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> mW - <NUM> mW, preferably <NUM> mW - <NUM> mW, laser repetition frequency <NUM> and the speed of the laser beam sweeping <NUM>/s.

Data as in Example <NUM>, wherein the marking of the laser marking <NUM> was produced with a near-infrared laser of a wavelength of <NUM>. The irradiation in the near-infrared range was carried out at the laser power between <NUM> mW - <NUM> mW, preferably <NUM> mW - <NUM> mW, the picosecond laser repetition frequency <NUM> and the speed of the laser beam sweeping <NUM>/s.

Under the influence of the laser radiation in the visible light and near-infrared range, a laser marking <NUM> is produced demonstrating an apparent increase of the fluorescence of the printing ink layer when illuminating it with the ultraviolet light, for example in the range of <NUM>, <NUM>, or <NUM>.

According to the invention, it is possible that the laser marking <NUM> is composed of, for example, at least one laser marking demonstrating enhanced radiation emission of the fluorescent pigments and/or dyes, and of at least one laser marking demonstrating suppressed radiation emission of the fluorescent pigments and/or dyes visible when illuminating it with the ultraviolet light. Alternatively, the laser marking <NUM> may be composed of, for example, at least two laser markings demonstrating enhanced radiation emission of the fluorescent pigments and/or dyes, as well as of at least two laser markings demonstrating suppressed radiation emission of the fluorescent pigments and/or dyes. This example is described in more detail below for a laminated substrate <NUM>, however, it is applicable also for a non-laminated substrate <NUM>.

In the case of irradiating the laser markings demonstrating the same intensities of radiation emission of the fluorescent pigments and/or dyes when illuminating them with the ultraviolet light, the irradiations may be performed in separate runs of the laser operation with different laser operating parameters or in the same run of the laser operation with the same laser operating parameters. In turn, in the case of irradiating at least two different laser markings demonstrating different intensities of radiation emission of the fluorescent pigments and/or dyes, the irradiation is carried out in separate runs of the laser operation with different laser operating parameters.

Therefore, the marking process introduces a first level security feature - the decay, visible with the naked eye, of a color demonstrating a change dependent on the observation angle of the laser marking <NUM>, and, simultaneously, a second level security feature - the decrease or increase of the fluorescence in the laser marking <NUM> under UV radiation, this being a hidden security feature that may be verified by means of a UV lamp.

In another embodiment of the invention, a substrate <NUM> may be produced from a plastic material, for example polycarbonate (PC), polyvinyl chloride (PVC), or polyester. The substrate <NUM> may be composed of a transparent foil, a white foil or a combination of transparent and white foils. The substrate <NUM>, in the sense of the invention, may be also a paper laminated with PC or PCV foils. Alternatively, onto the substrate <NUM>, at least one coating layer <NUM> may be deposited. A marking region <NUM> is deposited onto the substrate <NUM> or the coating layer <NUM>. This region is formed by a printing ink containing optically variable interference pigments. It may be printed using a currently available printing technique, for example screen printing, steel engraving, spraying, or pad printing. The thickness of the optically variable ink layer in the region <NUM> is from <NUM> to <NUM>, preferably from <NUM> to <NUM>. In the case of depositing the marking region <NUM> onto the substrate <NUM>, at least one coating layer <NUM> is applied onto the marking region <NUM>. The coating layer <NUM> may be of any thickness in the range from <NUM> to <NUM> or it may be a combination of foils of different thickness. The coating layer may be a foil, preferably a transparent elastic foil of a plastic material, or another layer made from a plastic material, as for example polycarbonate (PC) or polyester. A security document <NUM> according to present embodiment is produced from a stack of layers and may be composed of at least one coating layer <NUM> placed one on another, as well as on both sides of the substrate <NUM>. Also, the security document <NUM> may be composed, for example, from a coating layer <NUM>, a layer of the marking region <NUM>, another coating layer <NUM>, and then substrate <NUM> and subsequent coating layers <NUM>, as shown in <FIG>. Such a structure is subjected to a lamination process. The lamination is carried out as in the state of the art. The marking process, in this embodiment, according to the invention, is carried out after the lamination process, within the laminate of the security document <NUM> produced by binding the layers <NUM>, <NUM>. Subsequently, the above described marking process is carried out in the same manner, i.e., under the laser radiation in the ultraviolet range the effect of the optical variability is destroyed in the marking region <NUM> by decolorizing the optically variable ink located in the laser marking <NUM> of the marking region <NUM>. The laser marking <NUM> changes its interference properties and transforms from an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle, as shown in <FIG>. According to the invention, this another color may be, for example, metallic or the color silver. The laser marking <NUM> is produced using a UV laser, using the laser radiation of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>. Due to the subtleness of the interaction of the laser radiation with the optically variable ink layer of the marking region <NUM>, no unwanted stresses are generated that would affect the structure of the laminated security document <NUM>. The use of the UV laser of a wavelength of <NUM>, the radiation energy of which is not absorbed significantly by the coating layer <NUM>, for example of a polycarbonate foil (engraveable or non-engraveable), makes it possible to perform the marking process of the marking region <NUM> at different depths within the structure of the laminated security document <NUM>. The depth of the optically variable ink layer below the coating layer <NUM> may be from <NUM> to <NUM>. To that end, each time, for a given structure of the laminated security document <NUM>, appropriate irradiating time, frequency, and translation speed are chosen. The laser marking <NUM> is visible at any observation angle.

Onto a transparent polycarbonate foil sheet of a thickness of <NUM>, an optically variable ink layer was deposited, by means of screen printing, based on the Gold-Green pigment available from Zhuhai Qun Wang Technology Co. , and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> in the form of a laminate of a total thickness of approximately <NUM> with a white core and an optically variable ink located at a depth of about <NUM> - <NUM> from the laminate surface. Then, the laminate has been marked with an ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM>, and the speed between <NUM> and <NUM>/s. Under the influence of the laser radiation in the ultraviolet range the laser marking <NUM> is produced.

In another embodiment of the present invention shown in <FIG>, in order to obtain a further increase of the protection against counterfeiting, onto a laminated security document <NUM> a further security feature is added in the form of a second marking <NUM>, creating another variant of the securing element <NUM>. In this case, the securing element <NUM> is composed of the marking region <NUM>, the laser marking <NUM>, and the second marking <NUM>. In the case of marking the security document <NUM> with laser radiation of an appropriate wavelength, one may affect not only the marking region <NUM>, but also the laminate region <NUM>. While irradiating the marking region <NUM> using a first laser radiation of a wavelength in the range of <NUM> - <NUM>, the laser marking <NUM> is produced and, cumulatively, during the same irradiation step it is possible to produce the second marking <NUM> in the laminate region <NUM>. The laser marking <NUM> is visually recognizable due to an irreversible change of interference properties of the optically variable layer induced by the laser beam, and the second marking <NUM> is visually recognizable due to a local change, induced by the same laser beam, of the color of the security document <NUM> resulting from transformations and decompositions of the material. For example, the second marking <NUM> resulting from transforming the material adopts a third color, different from the marking region <NUM> and/or the laser marking <NUM>. A third color may be an effect of obscuring or blacking the laminate region <NUM>.

In this case, the second marking <NUM>, irradiated with a laser, is consistent with the laser marking <NUM> in the marking region <NUM>, because it is produced along with the laser marking <NUM> in the same operation by the same laser pointer, and the system for controlling its operation as well as the same laser operating parameters. Therefore, the presented solution does not require very precise positioning of the printing location of the optically variable ink.

Alternatively, it is also preferable that the process of marking the laser marking <NUM> in another color, for example the color silver, is produced employing the operating parameters, of the same laser, that are different than those used for the second marking <NUM>.

So, it is possible to use the laser of the appropriate wavelength for marking the marking region <NUM> by changing the interference properties of the laser marking <NUM> and, simultaneously, adding other personalized features in the form of the second marking <NUM>, in the laminate region <NUM>, in which the marking region <NUM> does not occur.

The second marking <NUM> may be in the form of any geometrical shape and/or a figure and/or a letter and/or a picture. Moreover, most importantly, the second marking <NUM> and the laser marking <NUM> may constitute a unity, for example, a matching geometrical shape and/or a figure and/or a letter and/or a picture, and a string of alphanumeric characters. Also, it is possible to create pictures that are not related to each other, such that, firstly, one produces the laser marking <NUM> and then, in a second process, the second marking <NUM> is engraved.

Totally, due to the laser processing, four regions are produced of different optical properties: in the marking region <NUM>, the effect of optical variability dominates due to the optically variable pigment layer of interference properties. In the region of the laser marking <NUM>, it is another color demonstrating no change dependent on the observation angle, for example metallic or the color silver. The laser marking <NUM> is visible at any observation angle. In the case of the second marking <NUM> the effect of blacking or obscuring dominates. The fourth color is the color of the laminate region <NUM>. Placing, onto the single laminate surface, the security features of four different optical properties increases the security level of the security document <NUM>.

Onto a white PVC foil sheet of a thickness of <NUM>, an optically variable Sicpa Star OVI Blue - Purple ink layer was deposited, by means of screen printing, free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> in the form of a laminate of a total thickness of approximately <NUM> with a white core and an optically variable ink located at a depth of about <NUM> - <NUM> from the surface of the coating layer <NUM> of the laminate. Then, the laminate has been marked with an ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM>, and the speed between <NUM> and <NUM>/s. Under the influence of the laser radiation the laser marking <NUM> and the second marking <NUM> are produced within the marking region <NUM> and the laminate region <NUM>, that complement each other.

Totally, due to the laser processing, four regions are produced of different optical properties in the visible radiation: in the marking region <NUM> the effect of optical variability dominates due to the optically variable pigment layer of interference properties. In the region of the laser marking <NUM> it is another color demonstrating no change dependent on the observation angle, for example metallic or the color silver. The laser marking <NUM> is visible at any observation angle. In the case of the second marking <NUM> the effect of blacking or obscuring dominates. The fourth color is the color of the laminate region <NUM>. Placing, onto the single laminate surface, the security features of four different optical properties increases the security level of the security document <NUM>.

According to another embodiment of the invention, illustrated in <FIG>, fluorescent pigments and/or dyes were added to an optically variable ink layer in the marking region <NUM>. Therefore, the laminated security document <NUM> has a securing element <NUM>, that is placed locally or on the whole surface of the security document <NUM>. At least one coating layer <NUM> is deposited onto this securing element <NUM>, wherein the securing element <NUM> comprises a marking region <NUM> composed of at least one printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes and free of additives changing the absorption spectrum of the printing ink layer, the marking region <NUM> comprising a laser marking <NUM> applied by laser radiation, the laser marking <NUM> being visually recognizable basing on an irreversible change of interference properties of the printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes, and on a transformation, within the laser marking <NUM>, of an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle.

The ratios of the used amounts of the optically variable pigment and the fluorescent additive may differ depending on the demanded covering effect of the optically variable ink and the fluorescence intensity, as well as on the types of employed optically variable pigments and fluorescent additives. Preferably, the amount of the optically variable pigment is at least <NUM> - <NUM> times bigger than that of the fluorescent additive in the form of the fluorescent pigments and/or dyes.

The marking process of the marking region <NUM> is carried out as in the example above. The substrate <NUM>, may be made from a plastic material, for example polycarbonate (PC), polyvinyl chloride (PVC), or polyester. The substrate <NUM> may be composed of a transparent foil, a white foil or a combination of transparent and white foils. Also, the substrate <NUM>, in the sense of this invention, may be a paper laminated with plastic materials, for example PC, PCV. Alternatively, at least one coating layer <NUM> may be applied onto the substrate <NUM>. A marking region <NUM> is applied onto the substrate <NUM> or the coating layer <NUM>. This region is a printing ink containing optically variable interference pigments with an addition of fluorescent pigments and/or dyes. It may be printed using a currently available printing technique, for example by screen printing, steel engraving, spraying or pad printing. The thickness of the optically variable ink layer in the region <NUM>, is from <NUM> to <NUM>, preferably from <NUM> to <NUM>. In the case the marking region <NUM> is applied onto the substrate <NUM>, at least one coating layer <NUM> is applied onto the marking region <NUM>. The coating layer <NUM> may have a thickness in the range from <NUM> to <NUM> or it may be a combination of foils of different thicknesses. The coating layer may be a foil, preferably a transparent elastic foil made from a plastic material, or another layer from a plastic material, such as for example polycarbonate (PC) or polyester. A security document <NUM> according to present embodiment, is produced from a stack of the layers and may be composed of at least one coating layer <NUM> placed one on another, as well as on both sides of the substrate <NUM>. Also, the security document <NUM> may be composed, for example, from a coating layer <NUM>, a layer of the marking region <NUM>, another coating layer <NUM>, and then substrate <NUM> and subsequent coating layers <NUM>, as shown in <FIG>. Such a structure is subjected to a lamination process. The lamination is carried out as in the state of the art. The marking process, in this embodiment, according to the invention, is carried out after the lamination process, within the laminate of the security document <NUM> produced by binding the layers <NUM>, <NUM>, shown in <FIG>. Subsequently, the above described marking process is carried out in the same manner, i.e., under the laser radiation in the ultraviolet range, visible radiation or infrared radiation, in the marking region <NUM>, one loses the color change effect of the laser marking <NUM> from an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle. Additionally, a change of the intensity of the emission of the fluorescent pigments and/or dyes may occur. <FIG> illustrates this embodiment. According to the invention, this another color may be, for example, metallic or the color silver. The laser marking <NUM> is produced using a UV laser, using the laser radiation of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>. Due to the subtleness of the interaction of the laser radiation with the optically variable ink layer of the marking region <NUM>, no unwanted stresses are generated that would affect the structure of the laminated security document <NUM>. Alternatively, a VIS laser may be used of a wavelength of <NUM>, a picosecond IR laser of a wavelength of <NUM>, or a fiber laser of a wavelength of <NUM>, the radiation energy of which is not absorbed significantly by the coating layer <NUM>, for example of a polycarbonate foil (engraveable or non-engraveable), this making it possible to perform the marking process of the marking region <NUM> at different depths within the structure of the laminated security document <NUM>. The depth of the optically variable ink layer containing fluorescent pigments and/or dyes below the coating layer <NUM> may be from <NUM> to <NUM>. To that end, each time, for a given structure of the laminated security document <NUM>, appropriate irradiation time, frequency, and translation speed are chosen. The laser marking <NUM> is visible at any observation angle.

According to the invention, the laser marking <NUM> is recognizable by a visible decrease or increase of the fluorescence intensity of the fluorescent pigments and/or dyes when illuminating the laser marking <NUM> with the ultraviolet light.

According to the invention, the laser marking <NUM> demonstrates a decrease of the fluorescence intensity of the fluorescent pigments and/or dyes if the laser radiation is used for the marking of a wavelength in the range from <NUM> to <NUM>, preferably of a wavelength of <NUM>.

Onto a transparent polycarbonate foil sheet of a thickness of <NUM>, an optically variable SICPA OVI® Magenta - Green ink layer was deposited, by means of screen printing, of a thickness of <NUM> - <NUM>, and with an addition of fluorescent pigments and/or dyes, where the ratio by weight of the optically variable pigments to the fluorescent pigments and/or dyes is <NUM>:<NUM>, and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> of a total thickness of approximately <NUM> with a white core and with the optically variable ink with an addition of fluorescent pigments and/or dyes at a depth of about <NUM> - <NUM> from the laminate surface. Then, the laminate has been marked with an ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM> and the speed between <NUM> and <NUM>/s. Under the influence of the laser radiation in the ultraviolet range a laser marking <NUM> is produced demonstrating, additionally, a decrease of the fluorescence when illuminating it with the ultraviolet light, for example in the range of <NUM> or <NUM>.

Alternatively, according to this variant of the invention, the laser marking <NUM> may also demonstrate an increase of the fluorescence intensity of the fluorescent pigments and/or dyes. To produce the laser marking <NUM> having an observable increase of the fluorescence intensity one uses the laser radiation of a wavelength in the visible radiation range, for example a green laser of a wavelength of <NUM>, or an infrared lasers of wavelengths from <NUM> to <NUM>, preferably of a wavelength of <NUM> or <NUM>.

Onto a transparent polycarbonate foil of a thickness of <NUM>, an optically variable OVMI® Magenta - Green ink layer was deposited, by means of screen printing, with an addition of fluorescent pigments and/or dyes with a ratio by weight of optically variable pigments to the fluorescent pigments and/or dyes equal to <NUM>:<NUM>, and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> of a total thickness of approximately <NUM> with a white core and with the optically variable ink located at a depth of about <NUM> - <NUM> from the laminate surface. Then, the laminate has been subjected to the marking process using a nanosecond fiber near-infrared laser of a wavelength of <NUM>. The irradiation process in the near-infrared range was carried out at the laser power of <NUM> mW - <NUM> mW, preferably <NUM> mW - <NUM> mW, the fiber laser repetition frequency of <NUM> and the speed of the laser beam sweeping of <NUM>/s. Under the influence of the laser radiation in the near-infrared range a laser marking <NUM> is produced demonstrating an increase of the fluorescence when illuminating it with the ultraviolet light, for example in the range of <NUM> or <NUM>.

Onto a polycarbonate substrate having a thickness of <NUM>, a marking region <NUM> was deposited, by means of screen printing, of a thickness of <NUM> - <NUM> in the form of an optically variable SICPA OVI® Green - Magenta ink layer and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible, with an addition of fluorescent pigments and/or dyes with a ratio by weight of the optically variable pigments to the fluorescent pigments and/or dyes of <NUM>:<NUM>. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> of a total thickness of approximately <NUM> with a white core, and the optically variable ink located at a depth of about. <NUM> - <NUM> from the laminate surface. The marking process was carried out with a near-infrared laser, preferably of a wavelength of <NUM>. The irradiation with the near-infrared Nd-Yag laser was carried out at a laser frequency of <NUM>, a laser power in the range of <NUM> W - <NUM> W, preferably <NUM> W-<NUM> W. Under the influence of the laser radiation in the near-infrared range a laser marking <NUM> is produced demonstrating no color changing effect in favor of perception of the color silver and an increase of the intensity of the emission of the visible radiation when illuminating it with the UV radiation in the range of <NUM>, <NUM>, or <NUM>.

Therefore, the laminated security document <NUM> has a first level security feature - the decay, visible with the naked eye, of the color changing effect of the laser marking <NUM>, as well as a second level security feature - the decrease or increase of the fluorescence in the laser marking <NUM> under UV radiation, this being a hidden security feature that may be verified by means of a UV lamp.

According to the present embodiment, the marking region <NUM> and the laser marking <NUM> exhibit fluorescent properties. In the case of marking the security document <NUM> with the laser radiation of the appropriate wavelength, one can affect not only the marking region <NUM>, but also the laminate region <NUM>. While irradiating the marking region <NUM> using the first laser radiation of a wavelength in the range of <NUM> - <NUM>, one produces a laser marking <NUM> and, cumulatively, during the same irradiation step it is possible to produce a second marking <NUM> in the laminate region <NUM>. In this case, the securing element <NUM> is composed of the marking region <NUM>, the laser marking <NUM>, and the second marking <NUM>. So, in the case of producing the second security feature in the form of the second marking <NUM>, the security document <NUM> has four regions of different optical properties, and an additional security feature in the form of the fluorescence. The laser marking <NUM> is visually recognizable due to an irreversible change of interference properties of the optically variable layer induced by the laser beam and a change of the fluorescence intensity, the second marking <NUM> is visually recognizable due to the local change of the color of the security document <NUM>, induced by the same laser beam, and resulting from transformation and decomposition of the material. For example, the second marking <NUM>, due to the material transformation, adopts a third color, different from the marking region <NUM> and/or the laser marking <NUM>. The third color may be an effect of obscuring or blacking the laminate region <NUM>.

Also, the second marking <NUM> in the laminate region <NUM> may be produced, for example, by the laser radiation of a wavelength in the range of <NUM> - <NUM> or by the laser radiation of a wavelength in the range of <NUM> - <NUM>.

In this case, the second marking <NUM> irradiated by the laser, is consistent with the laser marking <NUM> in the marking region <NUM>, because it is produced along with the laser marking <NUM>, in the same operation, by the same laser pointer, and the same system for controlling its operation as well as using the same laser operating parameters. Therefore, the presented solution does not require very precise positioning of the printing location of the optically variable ink with an addition of fluorescent pigments and/or dyes.

So, it is possible to use the laser of the appropriate wavelength for marking the marking region <NUM> by changing the interference properties of the laser marking <NUM> demonstrating, simultaneously, a change of the fluorescence intensity depending on the laser radiation used for performing the marking, and, simultaneously, adding other personalized features in the form of the second marking <NUM>, in the laminate region <NUM>, in which the marking region <NUM> does not occur. This solution is shown in <FIG>.

The second marking <NUM> may be in the form of any geometrical shape and/or a figure and/or a letter and/or a picture. Moreover, the second marking <NUM> and the laser marking <NUM> may constitute a unity, for example, a matching geometrical shape and/or a figure and/or a letter and/or a picture, and a string of alphanumeric characters. Also, it is possible to create pictures that are not related to each other, such that, firstly, one produces the laser marking <NUM> and then, in a second process, the second marking <NUM> is engraved.

If the marking region <NUM> is an optically variable ink with an addition of fluorescent pigments and/or dyes, then, by laser processing, six regions are produced of different optical properties: in the marking region <NUM> the effect of optical variability dominates due to the optically variable pigment layer of interference properties with an addition of fluorescent pigments and/or dyes. In the region of the laser marking <NUM> it is another color demonstrating no change dependent on the observation angle, for example metallic or the color silver with an addition of fluorescent pigments and/or dyes. The laser marking <NUM> is visible at any observation angle. For the second marking <NUM> the effect of blacking or obscuring dominates. The fourth color is the color of the laminate region <NUM>. Additionally, when illuminating with the ultraviolet light, for example in the range of <NUM>, <NUM> or <NUM>, security features are visible in the form of the fluorescence of the marking region <NUM> and the fluorescence of the laser marking <NUM>. If the laser marking <NUM> has been produced with a UV laser, then it exhibits a decrease of the fluorescence, whereas if it has been produced with a green laser of a wavelength of <NUM> or an infrared laser, then it exhibits an increase of the fluorescence. With this, the laser marking <NUM> may demonstrate a decreased or increased emission of the fluorescent pigments and/or dyes in comparison to the intensity of the emission of the marking region <NUM>. Therefore, the securing element <NUM>, under the ultraviolet light, may exhibit different intensities of the light emission from the fluorescent pigments and/or dyes by its different elements that are present in the security document <NUM>. Placing, onto the single laminate surface, the security features of six different optical properties increases the security level of the security document <NUM>.

According to another embodiment of the present invention, it is possible to employ, simultaneously, UV, visible light, and infrared lasers, this making possible to obtain, for example, eight different regions of different visual perceptions both in the visible radiation and UV wavelength range. It is shown in <FIG>. In this case one can obtain two additional regions demonstrating no color changing effect under the visible light and indistinguishable with the naked eye, but exhibiting different intensities under the ultraviolet light of a wavelength <NUM>, <NUM>, or <NUM>.

<FIG> shows the security document <NUM> before the marking process, demonstrating two colors. One of them is the color of the marking region <NUM> whereas the second color is the color of the laminate region <NUM>. Due to the marking process, the laser marking <NUM> may cover the whole marking region <NUM> or the marking region <NUM> excluding the elements of the marking region <NUM> that were not subjected to the marking process. The elements of the marking region <NUM> not subjected to the marking process are shown in <FIG> as the letters BCDEFG. In turn, the second marking <NUM> due to the material transformation adopts a third color, different from the marking region <NUM> and/or the laser marking <NUM>. When observing under the visible light, a securing element <NUM> is visible consisting of the color of the marking region <NUM>, the color of the laser marking <NUM> after performing the marking process, demonstrating no change dependent on the observation angle and of the color of the laminate region <NUM> and the third color of the second marking <NUM>. The same securing element <NUM> seen under the ultraviolet light exhibits a different color of the laminate region <NUM> seen under UV, the fluorescence of the marking region <NUM>, and the fluorescence of the laser marking <NUM>. The laser marking <NUM> may be composed of, for example, at least one laser marking 207a demonstrating an enhanced radiation emission of the fluorescent pigments and/or dyes, and of at least one laser marking 207b demonstrating a suppressed radiation emission of the fluorescent pigments and/or dyes. This is shown in <FIG>, where one can see, under the ultraviolet light, the differences of radiation emission of the fluorescent pigments and/or dyes of individual elements of the securing element <NUM>. The letters BCDEFG of the marking region <NUM> emit fluorescence more intensively than the region of the laser marking 207b of the decreased radiation emission from the fluorescent pigments and/or dyes and more weakly than the laser marking 207a exhibiting an enhanced emission in comparison to the intensity, shown here as the letters IJKL and the figures <NUM>. It should be noted that the above described intensity differences of the laser marking <NUM> are visible under UV light. In this case, the irradiation of the laser marking 207a, demonstrating enhanced radiation emission of the fluorescent pigments and/or dyes, as well as the laser marking 207b, demonstrating a suppressed radiation emission of the fluorescent pigments and/or dyes, is carried out in separate runs of the laser operation with different operating parameters. This situation is illustrated with the following example.

Onto a polycarbonate substrate having a thickness of <NUM>, a marking region <NUM> of a thickness of <NUM> - <NUM> was deposited, by means of screen printing, in the form of an optically variable SICPASTAR blue - purple ink layer and free of additives changing the absorption spectrum of the printing ink layer in order to adjust it to the wavelength of the used laser without which the marking would not be possible, along with an addition of fluorescent pigments and/or dyes with a ratio by weight of the optically variable pigments to the fluorescent pigments and/or dyes equal to <NUM>:<NUM>. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> of a total thickness of approximately <NUM> with a white core and the optically variable ink with an addition of fluorescent pigments and/or dyes at a depth of about <NUM> - <NUM> from the laminate surface.

In the case of marking the region <NUM> with a near-infrared laser, preferably of a wavelength of <NUM>, an effect of blacking or obscuring dominates.

The marking of the laser marking 207a demonstrating an increase of the fluorescence was carried out using a near-infrared laser, preferably of a wavelength of <NUM>. The irradiation with an Nd-Yag laser in the near-infrared range was carried out at the laser frequency of <NUM>, laser power in the range of <NUM> W - <NUM> W, preferably <NUM> W-<NUM> W. Under the influence of the laser radiation in the near-infrared range one produces the laser marking 207a demonstrating no color changing effect in favor of perceiving the color silver and demonstrating an increase of the intensity of the emission of the visible radiation when illuminating it with the UV radiation in the range of <NUM>, <NUM>, or <NUM>.

The marking of the laser marking 207b demonstrating a decrease of the fluorescence was carried out using an ultraviolet light laser, preferably of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM> and the speed between <NUM> and <NUM>/s. Under the influence of the laser radiation in the ultraviolet range one produces the laser marking 207b demonstrating a decrease of the fluorescence when illuminating it with the ultraviolet light in the range of <NUM>, <NUM>, or <NUM>.

Alternatively, the laser marking <NUM> may be composed of, for example, at least two laser markings 207a demonstrating an enhanced radiation emission of the fluorescent pigments and/or dyes, and of at least two laser markings 207b demonstrating a suppressed radiation emission of the fluorescent pigments and/or dyes. In this case, the irradiation of the laser markings demonstrating the same intensity of radiation emission of the fluorescent pigments and/or dyes may be carried out in separate runs of the laser operation with different laser operating parameters or in the same run of the laser operation with the same laser operating parameters.

In another embodiment of the invention, shown in <FIG>, a marking region <NUM> is located within the structure of a coating layer <NUM> above a laminated substrate <NUM>. On the surface of the coating layer <NUM> a lenticular element <NUM> is created. The lenticular element <NUM> may be located totally or partially above the marking region <NUM>. As a result of the marking process, carried out using a UV laser of a wavelength in the range from <NUM> to <NUM>, preferably <NUM>, and an appropriately prepared graphical design that is to be the subject matter of the laser marking <NUM>, and taking into consideration the type of the used lens, according to the state of the art knowledge, and the location depth of the optically variable ink layer, a laser marking <NUM> is created, shown in <FIG>. Due to the use of the lenses and the appropriate processing of the graphic design, the laser marking <NUM> is only visible at an appropriate observation angle. <FIG> shows the security document <NUM> with a securing element <NUM> composed of the marking region <NUM> in the form of a printing ink layer containing optically variable interference pigments and free of additives changing the absorption spectrum of the printing ink layer in order to adjust the absorption spectrum to the wavelength of the used laser without which the marking would not be possible, and a lenticular element <NUM>. In this embodiment, the lenticular element <NUM> is produced over the marking region <NUM> within the coating layer <NUM> (not shown in the drawing), that produces an angle effect, i.e., the laser marking <NUM> located in the marking region <NUM> is visible at an appropriate observation angle. If one tilts the security document <NUM> changing the observation angle, as shown in <FIG>, then the laser marking <NUM> becomes visible in the marking region <NUM>, in a color exhibiting no change dependent on the observation angle. In this case, the method of carrying out the process of marking the laser marking <NUM> is the same as described for one of the above embodiments of the laminated security document <NUM>.

Also, a possibility exists of using a printing ink layer <NUM> containing optically variable interference pigments, and, additionally, pigments and/or dyes having fluorescent properties. In such case, the laser marking <NUM> will also be visible under UV light of a wavelength <NUM>, <NUM>, <NUM> only at an appropriate observation angle.

Onto a transparent polycarbonate foil of a thickness of <NUM> an optically variable SICPASTAR Blue-Purple ink layer was deposited by means of screen printing. The sheet has been completed with other foils, including white ones and transparent ones, such that to obtain, after the lamination process, the security document <NUM> of a total thickness of approximately <NUM> with a white core and the optically variable ink located at a depth of about <NUM> - <NUM> from the laminate surface. The lamination process was carried out using lamination plates having a lenticular structure in such locations that the lenticular element produced in the laminated security document <NUM> totally or partially covers the location of the optically variable ink layer. Then, the laminate has been marked with an ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM> and the speed between <NUM> and <NUM>/s. A specially prepared design of the marked picture was used for the irradiating, dedicated to lenses of given characteristics. Under the influence of the laser radiation in the ultraviolet range one produces a laser marking <NUM> only visible at an appropriate observation angle.

In another embodiment of the invention, shown in <FIG>, an optically variable ink was used with an addition of fluorescent pigments and/or dyes in a marking region <NUM>. This region is located within the structure of a coating layer <NUM> over a laminated substrate <NUM>. A lenticular element <NUM> is produced on the surface of the coating layer <NUM>. The lenticular element <NUM> may be located totally or partially over the marking region <NUM>. As a result of the marking process, carried out using a UV laser of a wavelength in the range from <NUM> to <NUM>, a visible light laser or an IR laser of a wavelength in the range of from <NUM> to <NUM> and an appropriately prepared graphic design that is to be the subject mater of the laser marking <NUM> and taking into consideration the type of the used lens, according to the state of the art knowledge, and the location depth of the optically variable ink layer with an addition of fluorescent pigments and/or dyes, a laser marking <NUM> is produced, shown in <FIG>. Due to the use of the lenses and the appropriate processing of the graphic design, the laser marking <NUM> is only visible at an appropriate observation angle. <FIG> shows the security document <NUM> with a securing element <NUM> composed of the marking region <NUM> in the form of a printing ink layer containing optically variable interference pigments and free of additives changing the absorption spectrum of the printing ink layer in order to adjust the absorption spectrum to the wavelength of the used laser without which the marking would not be possible, containing an addition of fluorescent pigment(s) and/or dye(s) and a lenticular element <NUM>. In this embodiment, the lenticular element <NUM> is produced over the marking region <NUM> within the coating layer <NUM> (not shown in the drawing), that produces an angle effect, i.e., the laser marking <NUM> located in the marking region <NUM> is visible at an appropriate observation angle. If one tilts the security document <NUM> changing the observation angle, as shown in <FIG>, then the laser marking <NUM> becomes visible in the marking region <NUM>, in a color exhibiting no change dependent on the observation angle. Also, the marking becomes visible under UV light at an appropriate observation angle and depending on the used laser. One can see a decrease or an increase of the fluorescence of the locations of the laser marking <NUM>. In this case, the method of carrying out the process of marking the laser marking <NUM> is the same as described for one of the above embodiments of the laminated security document <NUM>.

Onto a transparent polycarbonate foil of a thickness of <NUM>, an optically variable SICPASTAR Blue-Purple ink layer was deposited, by means of screen printing, with an addition of fluorescent pigments and/or dyes. The sheet has been completed with other foils, including white ones and transparent ones such that to obtain, after the lamination process, the security document <NUM> of a total thickness of approximately <NUM> with a white core and the optically variable ink with an addition of fluorescent pigments and/or dyes at a depth of about <NUM> - <NUM> from the laminate surface. The lamination process was carried out using lamination plates having a lenticular structure in such locations that the lenticular element produced in the laminated security document <NUM> totally or partially covers the location of the optically variable ink layer with the addition of fluorescent pigments and/or dyes. Then, the laminate has been marked with an ultraviolet light laser of a wavelength of <NUM>. The irradiation process was carried out at the laser power between <NUM> and <NUM> W, frequency <NUM> - <NUM>, preferably <NUM>-<NUM> and the speed between <NUM> and <NUM>/s. A specially prepared design of the marked picture was used for the irradiating, dedicated to lenses of given characteristics. Under the influence of the laser radiation in the ultraviolet range one produces a laser marking <NUM> only visible at an appropriate observation angle both in the visible radiation as well as in the UV light.

By changing, during the marking process, such parameters as the laser power, the irradiating time, frequency, translation speed, etc., results of the marking process may be changed in a broad range. In this manner, in addition to modifying, partially or totally, an optically variable printing ink layer or an optically variable printing ink layer with an addition of fluorescent pigments and/or dyes, one can produce, with the laser, also other types of the marking, such as blacking effects on the substrate of the laminated security document <NUM>.

Claim 1:
A laminated security document (<NUM>) with a securing element (<NUM>) located locally or on the whole surface of the security document (<NUM>), at least one coating layer (<NUM>) being deposited onto the securing element (<NUM>), the securing element (<NUM>) comprising a marking region (<NUM>) composed of at least one printing ink layer containing optically variable interference pigments, the printing ink layer further containing fluorescent pigments and/or fluorescent dyes and being free of additives changing the absorption spectrum of the printing ink layer, the marking region (<NUM>) comprising at least one laser marking (<NUM>) applied by laser radiation, the laser marking (<NUM>) being visually recognizable basing on an irreversible change of interference properties of the printing ink layer containing optically variable interference pigments and fluorescent pigments and/or dyes, and on a transformation, within the laser marking (<NUM>), of an original color demonstrating a change dependent on the observation angle into another color demonstrating no change dependent on the observation angle, wherein the laser marking (<NUM>) is recognizable basing on a change of the intensity of light emission from the fluorescent pigments and/or fluorescent dyes when illuminating the laser marking (<NUM>) with ultraviolet light.