EP2727741A2

EP2727741A2 - Valuable document with an optically variable structure (variants)

Info

Publication number: EP2727741A2
Application number: EP12803793.4A
Authority: EP
Inventors: Arkadiy Vladimirovich Trachuk; Andrey Borisovich Kuryatnikov; Alexandr Georgievich Pisarev; Igor Vasilievich Pavlov; Aleksandr Igorievich Mochalov; Alexey Vitalevich Salunin; Anna Menashevna Rytikova; Vladimir Ivanovich Shapinov; Konstantin Gennadievich Rybin; Dmitry Petrovich BOLOTOV; Elena Mikhailovna Fedorova; Galina Sergeevna Baranova
Original assignee: Goznak FGUP
Current assignee: Goznak JSC
Priority date: 2011-06-30
Filing date: 2012-06-22
Publication date: 2014-05-07
Anticipated expiration: 2032-06-22
Also published as: CN103764403A; RU2467879C1; CO6920269A2; WO2013002680A2; EP2727741B1; EP2727741A4; WO2013002680A3; CN103764403B

Abstract

Valuable document comprises a coating in the form of a printed raster that is made up of at least one colour which is different from the colour of the document base. The document also comprises a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, is oriented substantially parallel to lines of the printed raster and together with the coating forms a latent image which is not discernible when the document is viewed at right angle. At least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, as a result of which the latent image becomes visible in the form of coloured elements or a single-colour region when the viewing angle changes. Changing the viewing direction by 180 degrees without any change in the viewing angle results in a change in the optical density or colour gamut of at least a part of the latent image. The invention enhances the counterfeit protection of a valuable document with an optically variable image and makes it possible for an untrained user to carry out a visual authenticity check.

Description

FIELD OF THE INVENTION

The invention relates to a counterfeit- protected valuable document such as an information medium with an optically variable structure that attests to the authenticity of the medium, and is applicable in the production of banknotes and securities. The medium can also refer to cards which are used for person identification or for committing transactions or services.
Optically variable structure is used as a feature that can be checked both without technical aids and using simple available means, if necessary, along with other features to verify the authenticity of a valuable document.

BACKGROUND ART

A conventional banknote ( RU 2161092 C2 , B32B 29/02, 27.12.2000) comprises a printed pattern formed by parallel lines and an additional embossed three-dimensional linear structure. Due to a certain mutual arrangement of the printed and three-dimensional structures the printed lines are visible when the banknote is viewed perpendicular to the surface and not visible when the document is viewed at an acute angle.
Another information medium ( CA 1019012 A , B32B 29/02, 11.10.1997) comprises an optically variable structure formed by a printed raster with straight equispaced elements and a three-dimensional raster with straight equispaced elements, the three-dimensional raster being positioned relative to the printed raster such that when the information medium is viewed perpendicularly to its surface all printed information is visible, while at an acute angle of view of the surface only that part which is not occluded by the three-dimensional raster can be seen.
RU 2235021 C2, 27.08.2004 , teaches an information medium comprising a printed raster and a three-dimensional raster arranged so that to create moir in the form of smoothly blending colour fringes.
RU 2249638 C1 discloses a method of manufacturing securities using a metallographic plate with asymmetrical line profile. However, the method is aimed at producing engraving lines that are coloured unevenly across the direction thereof. The method is not directed at embossing followed by formation of differently coloured moir fringes.
Patent application RU 2010132328 , belonging to the present applicant, discloses an information medium comprising a printed raster and a three-dimensional raster, which are arranged so that to create a moir pattern in the form of smoothly blending coloured fringes, and the three-dimensional raster may contain areas made by bleached ink, thus when the angle of view of the valuable document changes the moir fringes seem to be moving.
This technical solution is the most relevant prior art to the present invention.

SUMMARY OF THE INVENTION

The object of the invention is to improve the security properties of an optically variable feature which can be observed when the angle of inclination and/or the direction of viewing of a valuable document is changed, as a result of using at least partially asymmetric profile of a three-dimensional raster which causes disappearance and/or change of the colour gamut of the image of an area of the valuable document observed at the same angle but rotated 180 degrees.
The object of the invention is to improve an optically variable security feature as a result of the effect of changing the optical density or colour gamut of an area of a valuable document made with the use of a three-dimensional raster with at least partially asymmetrical profile of the line cross section, observed when the viewing direction of the valuable document is changed by 180 degrees without any change in the angle of inclination, thereby facilitating the check of the document authenticity by an untrained user.
The effect of changing the colour gamut comprises changing the colour of moir fringes or single-colour areas of the image when the viewing direction of the valuable document changes, the colour being changed under the CMY to RGB conversion model.
"CMY to RGB conversion" as used here refers to the effect of changing the colour gamut where pure colours (CMY) are replaced with mixed colours (RGB), that is cyan, magenta yellow are changed to red (as a mix of magenta and yellow), blue (as a mix of magenta and cyan), green (as a mix of blue and yellow).
The invention can be implemented in four embodiments.
The object of the invention is accomplished as described below.
According to a first embodiment, a valuable document with an optically variable structure that attests to the authenticity of the document comprises a coating in the form of a printed raster that is made up of at least one colour which is different from the colour of the main document, and a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, is oriented substantially parallel to lines of the printed raster and together with the coating forms a latent image which is not discernible when the document is viewed at right angle to the surface; wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, so that when the viewing angle changes the latent image becomes visible in the form of coloured elements or a single-colour region, and when the viewing direction changes by 180 degrees without any change in the viewing angle the effect of changing the optical density or the colour gamut of at least a part of the latent image appears.
Additionally, a first embodiment of the invention can be characterized in that:

lines of the printed and three-dimensional rasters can have a constant and/or variable width, and a constant and/or variable spacing between adjacent lines;
lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric), and lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum;
lines of the three-dimensional raster have a constant and/or variable depth and/or different asymmetrical cross-section line profile.
parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour variable;
lines of the printed raster can further have different luminescence colour under UV and/or IR radiation;
lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.

According to a second embodiment, a valuable document with an optically variable structure that attests to the authenticity of the document comprises a coating in the form of a printed raster, and a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile, and the width of lines and the spacing between lines of the printed and three-dimensional rasters and mutual orientation of the rasters are selected so that they form a latent image, and when the valuable document is viewed at an angle multi-colour moir fringes are observed and the latent image is not discernible; at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, so that when the viewing direction changes by 180 degrees without any change in the viewing angle the latent image becomes visible against the background of multi-colour moir fringes owing to the change in the colour gamut of the coloured moir part lying in the area of the three-dimensional raster with asymmetric cross-section line profile.
The second embodiment can be further characterized in that:

lines of the printed and three-dimensional rasters can be differently oriented relative each other, have a constant and/or a variable width, and a constant and/or variable spacing between adjacent lines;
lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric);
lines of the three-dimensional raster can have a constant and/or variable depth and/or different asymmetrical cross-section line profile;
lines of the three-dimensional raster can be single- or multi-coloured;
lines of the three-dimensional raster can be coloured throughout the length and/or on separate areas;
parameters of the printed and three-dimensional rasters further form different moir structures and/or visual effects, including latent and/or colour variable;
the printed raster is formed of lines creating an image which is seen when the document is viewed at right angle;
lines of the printed raster can further have different luminescence colour under UV and/or IR radiation;
lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.

According to a third embodiment, a valuable document with an optically variable structure that attests to the authenticity of the document comprises a coating in the form of a printed raster, and a three-dimensional raster made on a transparent material and arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, the width of lines and the spacing between lines of the printed and three-dimensional rasters and mutual orientation of the rasters are selected such that coloured moiré fringes are observed when the viewing angle changes; at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25 forming a latent image, so that when the viewing direction changes by 180 degrees without any change in the viewing angle the latent image becomes visible against the background of coloured moiré fringes owing to a change in the colour gamut of the portion of moiré fringes lying in the area of lines with asymmetric cross-section profile, and as the viewing angle is simultaneously changed boundaries of the coloured moiré fringes seem to be moving.
The third embodiment can be further characterized in that:

lines of the printed and three-dimensional rasters can be differently oriented relative each other, have a constant and/or variable width, and a constant and/or variable spacing between adjacent lines;
lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric);
lines of the three-dimensional raster can have a constant and/or variable depth and/or different asymmetrical cross-section line profile;
parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour variable;
lines of the printed raster can further have different luminescence colour under UV and/or IR radiation;
lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.

According to a fourth embodiment, a valuable document with an optically variable structure that attests to the authenticity of the document comprises a coating in the form of a printed raster including lines formed in at least two colours having indistinguishable (close) tints in the visible spectrum or by colorless inks distinguishable in the absorption of optical radiation in the IR spectrum and/or in the luminescence colour under UV and/or IR radiation, and a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, the width of lines and the spacing between lines of the printed and three-dimensional rasters and mutual orientation of the rasters are selected such that they form a latent image which can be seen only when the valuable document is viewed under an UV illuminator and/or an IR visualizer; at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, so that when the viewing angle of the valuable document changes single- or multi-colour moiré fringes are observed, and when the viewing direction changes by 180 degrees without any change in the viewing angle the latent image becomes visible against the background of the single- or multi-colour moiré fringes owing to the change in the optical density or the colour gamut of the portion of moiré fringes lying in the area of the three-dimensional raster with asymmetric cross-section profile.
The fourth embodiment can be further characterized in that:

lines of the printed and three-dimensional rasters can be differently oriented relative each other, have a constant and/or a variable width, and a constant and/or variable spacing between adjacent lines;
lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric);
lines of the three-dimensional raster can have a constant and/or variable depth and/or different asymmetrical cross-section line profile;
parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour-variable.

The effect of changing the colour gamut of moiré fringes or single-colour areas of the image under the CMY to RGB model is ensured by the fact that the boundary of two or more colours of the printed raster is predominantly located on sloping areas of the three-dimensional raster having an asymmetrical section line profile, and when the viewing direction of the information medium changes without any change in the viewing angle the visible sloping surface area of the line of the three-dimensional raster changes as well. Thus, when the viewing direction of the medium changes, two or more colours of the printed raster mix to create the impression of changing the colour gamut of moiré fringes or one-colour areas according to the CMY to RGB model. When individual areas of the three-dimensional raster are painted with translucent inks or the three-dimensional raster with an asymmetrical line is embossed on a transparent layer, moiré fringes are observed at any viewing angle of the valuable document, and the impression of apparently moving moiré fringes is intensified.
Various moiré patterns and other visual including colour effects can be obtained depending on parameters of the printed and linear raster, their relationships, as well as profiles of symmetrical and asymmetrical cross-sections of the three-dimensional raster.
Preferably the angle between the direction of lines of the printed and three-dimensional rasters is from 0 to 45 degrees.
In an embodiment of a valuable document with small angles between the direction of the printed and three-dimensional rasters wide moiré fringes are observed, this enabling the creation of a composite image, each part of which, for example, individual symbols or characters, when the medium is viewed at different angles and different directions, will completely have its own independent colour, also varying according to the CMY to RGB model when the viewing direction of the valuable document changes by 180 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is illustrated by the following drawings.

FIG. 1 is a side view of superimposition of a three-dimensional and printed raster according to a first embodiment of the invention.
FIG 2 is a top view of superimposition of a three-dimensional and printed raster according to a first embodiment of the invention.
FIG. 3 (3a-3d) shows an image according to a first embodiment when the document is viewed at different angles of inclination and rotated 180 degrees, where 3a shows the view of the document at the right angle of observation; 3b shows the view of the document when the viewing angle of the document changes in the plane perpendicular to the direction of lines of the three- dimensional raster; 3c shows the view of the document at the same angle, but rotated 180 degrees; 3d shows the view of the document when the viewing angle changes in a plane parallel to the direction of lines of the three-dimensional raster.
FIG. 4 is a side view of superimposition of a three-dimensional and printed raster according to a second embodiment of the invention.
FIG. 5 is a top view of superimposition of a three-dimensional and printed raster according to a second embodiment of the invention.
FIG. 6 shows an image according to a second embodiment, when the document is viewed at an angle of inclination and rotated 180 degrees, where 6a shows the view of the document at the right angle of view; 6b shows the view of moiré fringes when the document is viewed from one side; 6c shows the view of moiré fringes and a latent element when the document is viewed rotated 180 degrees relative to 6b.
FIG. 7 is a side view of superimposition of a three-dimensional and printed raster according to a third embodiment of the invention.
FIG. 8 is a top view of superimposition of a three-dimensional and printed raster according to a third embodiment of the invention.
FIG. 9 shows an image according to a third embodiment when the document is viewed at different angles of inclination and rotated 180 degrees, where 9a shows the view of moiré fringes when the document is viewed from one side; 9b shows the view of moiré fringes and a latent element when the document is viewed rotated 180 degrees; 9c shows moving moiré fringes when the document is inclined relative to 9a; 9d shows moving moiré fringes when the document is inclined relative to 9b.
FIG. 10 is a top view of superimposition of a three-dimensional and printed raster according to a fourth embodiment of the invention.
FIG. 11 shows an image according to a fourth embodiment when the document is viewed under ordinary light, under UV radiation, and as seen in an IR visualizer, where 11a shows the document under ordinary light at any angle of inclination and at right angle under UV radiation or in an IR visualizer; 11b shows the view of moiré fringes under UV radiation when the document is viewed at an angle; 11c shows the view of moiré fringes and a latent element under UV radiation and rotated 180 degrees; 11d shows the view of moiré fringes when the document viewed in an IR visualizer at an angle; 11e shows the view of moiré fringes and a latent element when the document is viewed in an IR visualizer rotated 180 degrees.

BEST EMBODIMENT OF THE INVENTION

The invention will be further illustrated by following examples.

Example 1 (Figs. 1, 2 and 3)

A valuable document, as shown in Fig. 1, is made on a paper base (3) and comprises a printed raster (1) made by offset printing and a three-dimensional raster (2) with an asymmetric line profile, which is applied by blind embossing using intaglio printing, lines of the three-dimensional raster being parallel to the printed raster lines. The printed raster (1) comprises alternating, equispaced lines of three different colours - yellow, magenta, and blue, having a constant equal width. The three-dimensional raster (2) comprises alternating asymmetrical profile lines which form a latent image as shown in Fig. 2.
When the document is observed at right angle a uniformly coloured field (3a) can be seen. As the viewing angle of the document changes in the plane perpendicular to the direction of lines of the three-dimensional raster (3b) at an angle, latent elements having colours of the printed raster lines become visible. When the document is rotated by 180 degrees (3c) latent elements having mixed colours become visible owing to a change in the image colour gamut (orange, green, purple). When the document is viewed at an angle in a plane parallel to lines of the three-dimensional raster (3d), an additional latent element (4) can be seen.

Example 2 (Figs. 4, 5 and 6)

A valuable document, as shown in Figs. 4, 5, is made on a paper base (7) and comprises a printed raster (5) made by three-colour offset printing and a three-dimensional linear raster (6) made by blind embossing using intaglio printing, lines of the three-dimensional raster being rotated relative coloured lines of the printed raster at the angle of 15 degrees.
The printed raster comprises alternating, equispaced lines of three different colours - yellow, magenta, and blue, having a constant equal width. Line of each colour exhibits visible luminescence under UV radiation in the wavelength range of 330-370 nm, the luminescence colour being different for lines of each colour.
The three-dimensional raster comprises alternating lines of the same thickness, but the spacing between the lines is twice the width of the lines.
The three-dimensional raster is made partially with symmetrical profile lines (8), and partially with asymmetrical profile lines (9) which form a latent image as shown in Fig. 5
When the document is observed at right angle a single- colour area (6a) is observed. As the viewing angle of the document (6b) changes yellow, blue, purple moiré fringes can be seen. When the document is rotated 180 degrees (6c) a latent image formed in the area of the three-dimensional raster with asymmetrical line profile becomes visible owing to the change in the moiré image colour gamut to orange, green, purple.
When the document is observed under an UV source with a wavelength range of 330 - 370 nm a pattern of coloured moiré fringes is observed as a result of the change in the luminescence colour. Visual effect of observation of the latent image is similar to that described above.

Example 3 (Figs. 7, 8 and 9)

A valuable document, as shown in Fig. 7, is made on a plastic base (13) and comprises a printed raster (12) produced by three-colour offset printing and a three-dimensional linear raster (11) applied by blind embossing using intaglio printing on a transparent upper layer (10) applied over the printed raster, whose lines are rotated from the coloured lines of the printed raster at the angle of 10 degrees. The printed raster comprises alternating equispaced lines of three different colours - yellow, magenta, and blue, having a constant equal width. The three-dimensional raster comprises alternating lines of the same thickness, but the spacing between the lines is twice the width of the lines. The three-dimensional raster is formed partially of symmetrical profile lines (14) and partially of asymmetrical profile lines (15) which form a latent image as shown in Fig. 8.
When the document is observed at an angle in a plane perpendicular to the direction of the three-dimensional raster lines (9a) yellow, blue, purple moiré fringes can be seen. When the document (9c) is inclined relative to the position (9a) the moiré fringes seem to be moving in the transverse direction. When the document is rotated 180 degrees (9b) a latent image formed in the area of three-dimensional raster with asymmetrical line profile becomes visible as a result of changing the colour gamut of moiré fringe image to orange, green, purple, and when the document (9d) is inclined the moiré fringes also seem to be moving in the transverse direction.

Example 4 (Figs. 10 and 11)

A valuable document, as shown in Figs. 10 and 11, is made on a paper base (16) and comprises a printed raster (19) formed by two-colour offset printing, where the colours are similarly light gray, and a three-dimensional raster (17) applied by a blind embossing using intaglio printing, lines of the three-dimensional raster being rotated relative to the printed raster lines at an angle of 17 degrees. The printed raster comprises alternating equispaced lines formed by two inks of the same gray colour, but having different UV and IR properties, having a constant equal width, and when viewed in ordinary light the raster is visually perceived as a single-colour area (11a). The inks have different luminescence colour when exposed to UV radiation in the wavelength range of 330-370 nm, and different IR absorption properties in the wavelength range of 700-1100 nm. The first ink fluoresces red under UV radiation, while the second ink fluoresces green. The first ink has a broad absorption spectrum in the wavelength range of 700-1100 nm, while the second ink selectively absorbs in the range of 700-860 nm.
The three-dimensional raster comprises alternating lines having the same thickness, but the spacing between the lines is twice the width of the lines.
A part of the three-dimensional raster is formed with lines rotated 90 degrees (18), which form a latent image. When the document is viewed at any angle in ordinary light a single-colour light gray image pixel is observed in the area of the security feature (11c, 11e).
When the document is observed at right angle under UV light of 365 nm, a luminous yellow image element is observed in the region of the security feature. When the document is observed at an angle (11b) alternating green and red moiré stripes are observed in the field of the security feature. When the document is rotated 180 degrees (11c) a latent image can be seen as a result of the fact that there are no moiré fringes in the latent element region.
When the document is viewed in an IR visualizer at right angle a monochromatic gray area is observed. When the document is observed at an angle in the IR visualizer in the range of 810 nm (11d) alternating dark Moiré fringes are visible. When the document is rotated 180 degrees (11e) the latent image becomes visible due to the fact that there are no moiré fringes in the latent element.
When the document is viewed at an angle in the IR visualizer in the range of 940 nm a dark region is visible without moiré fringes.

Industrial Applicability

The invention provides a counterfeit-protected valuable document with an optically variable image, which makes it possible for an untrained user to carry out a visual authenticity check both without technical aids and using simple available means.

Claims

A valuable document with an optically variable structure that attests to the authenticity of the document, comprising a coating in the form of a printed raster that is made up of at least one colour which is different from the colour of the document base, and a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, is oriented substantially parallel to lines of the printed raster and together with the coating forms a latent image which is not discernible when the document is viewed at right angle to the surface, wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, so that when the viewing angle changes, the latent image becomes visible in the form of coloured elements or a single-colour region, and when the viewing direction changes by 180 degrees without any change in the viewing angle, the effect of changing the optical density or the colour gamut of at least a part of the latent image appears.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 1, wherein lines of the printed and three-dimensional rasters can have a constant and/or variable width, and a constant and/or variable spacing between adjacent lines.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 1, wherein lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric), and lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 1, wherein lines of the three-dimensional raster have a constant and/or variable depth and/or different asymmetrical cross-section line profile.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 1, wherein parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour variable.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 1, wherein lines of the printed raster can further have different luminescence colour under UV and/or IR radiation.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 1, wherein lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.
A valuable document with an optically variable structure that attests to the authenticity of the document, comprising a coating in the form of a printed raster, and a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile, and the width of lines and the spacing between lines of the printed and three-dimensional rasters and the mutual orientation of the rasters are selected such that they form a latent image, and when the valuable document is viewed at an angle, multi-colour moiré fringes are observed and the latent image is not discernible, and wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, so that when the viewing direction changes by 180 degrees without any change in the viewing angle, the latent image becomes visible against the background of multi-colour moiré fringes owing to a change in the colour gamut of the coloured moiré part lying in the region of the three-dimensional raster with asymmetric cross-section line profile.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the printed and three-dimensional rasters can be differently oriented relative each other, have a constant and/or a variable width, and a constant and/or variable spacing between adjacent lines.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric).
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the three-dimensional raster can have a constant and/or variable depth and/or different asymmetrical cross-section line profile.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the three-dimensional raster can be single- or multi-coloured.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the three-dimensional raster can be coloured throughout the length and/or on separate areas.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour variable.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein the printed raster is formed of lines creating an image which is seen when the document is viewed at right angle.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the printed raster can further have different luminescence colour under UV and/or IR radiation.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 8, wherein lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.
A valuable document with an optically variable structure that attests to the authenticity of the document, comprising a coating in the form of a printed raster, and a three-dimensional raster made on a transparent material and arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, the width of lines and the spacing between lines of the printed and three-dimensional rasters and the mutual orientation of the rasters are selected such that coloured moiré fringes are observed when the viewing angle changes, and wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25 forming a latent image, so that when the viewing direction changes by 180 degrees without any change in the viewing angle, the latent image becomes visible against the background of coloured moiré fringes owing to a change in the colour gamut of the portion of moiré fringes lying in the region of lines with asymmetric cross-section profile, and as the viewing angle is simultaneously changed, boundaries of the coloured moiré fringes seem to be moving.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 18, wherein lines of the printed and three-dimensional rasters can be differently oriented relative each other, have a constant and/or variable width, and a constant and/or variable spacing between adjacent lines.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 18, wherein lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric).
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 18, wherein lines of the three-dimensional raster can have a constant and/or variable depth and/or different asymmetrical cross-section line profile.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 18, wherein parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour variable.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 18, wherein lines of the printed raster can further have different luminescence colour under UV and/or IR radiation.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 18, wherein lines of the printed raster can further exhibit different absorption of optical radiation in the IR spectrum.
A valuable document with an optically variable structure that attests to the authenticity of the document, comprising a coating in the form of a printed raster including lines formed in at least two colours having indistinguishable (close) tints in the visible spectrum or by colorless inks distinguishable in the absorption of optical radiation in the IR spectrum and/or in the luminescence colour under UV and/or IR radiation, and a three-dimensional raster arranged relative to the coating so that the three-dimensional raster is at least partially disposed on the coating, the width of lines and the spacing between lines of the printed and three-dimensional rasters and the mutual orientation of the rasters are selected such that they form a latent image which can be seen only when the valuable document is viewed under an UV illuminator and/or in an IR visualizer, and wherein at least a portion of lines of the three-dimensional raster has an asymmetric cross-section profile with an aspect ratio of not less than 1:1.25, so that when the viewing angle of the valuable document changes, single- or multi-colour moiré fringes are observed, and when the viewing direction changes by 180 degrees without any change in the viewing angle, the latent image becomes visible against the background of the single- or multi-colour moiré fringes owing to a change in the optical density or the colour gamut of the portion of moiré fringes lying in the region of the three-dimensional raster with asymmetric cross-section profile.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 25, wherein lines of the printed and three-dimensional rasters can be differently oriented relative each other, have a constant and/or a variable width, and a constant and/or variable spacing between adjacent lines.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 25, wherein lines of the printed and three-dimensional rasters can have various configurations (straight, curved, including concentric).
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 25, wherein lines of the three-dimensional raster can have a constant and/or variable depth and/or different asymmetrical cross-section line profile.
A valuable document with an optically variable structure that attests to the authenticity of the document according to claim 25, wherein parameters of the printed and three-dimensional rasters further form different moiré structures and/or visual effects, including latent and/or colour-variable.