WO2011079347A1 - Optically variable device - Google Patents

Optically variable device Download PDF

Info

Publication number
WO2011079347A1
WO2011079347A1 PCT/AU2010/001672 AU2010001672W WO2011079347A1 WO 2011079347 A1 WO2011079347 A1 WO 2011079347A1 AU 2010001672 W AU2010001672 W AU 2010001672W WO 2011079347 A1 WO2011079347 A1 WO 2011079347A1
Authority
WO
WIPO (PCT)
Prior art keywords
optically variable
variable device
device according
relief elements
segments
Prior art date
Application number
PCT/AU2010/001672
Other languages
French (fr)
Inventor
Robert Arthur Lee
Original Assignee
Securency International Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to AU2010900012A priority Critical patent/AU2010900012A0/en
Priority to AU2010900012 priority
Application filed by Securency International Pty Ltd filed Critical Securency International Pty Ltd
Publication of WO2011079347A1 publication Critical patent/WO2011079347A1/en

Links

Classifications

    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B27/00Other optical systems; Other optical apparatus
    • G02B27/22Other optical systems; Other optical apparatus for producing stereoscopic or other three dimensional effects
    • G02B27/2228Stereoscopes or similar systems based on providing first and second images situated at first and second locations, said images corresponding to parallactically displaced views of the same object, and presenting the first and second images to an observer's left and right eyes respectively
    • G02B27/225Stereoscopes or similar systems based on providing first and second images situated at first and second locations, said images corresponding to parallactically displaced views of the same object, and presenting the first and second images to an observer's left and right eyes respectively of the autostereoscopic type, i.e. left and right images projected to the left and right eyes of an observer who is not required to view the images through optical systems placed adjacent to the eyes
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/18Diffraction gratings
    • G02B5/1828Diffraction gratings having means for producing variable diffraction
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03HHOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00Holographic processes or apparatus using light, infra-red or ultra-violet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/0005Adaptation of holography to specific applications
    • G03H1/0011Adaptation of holography to specific applications for security or authentication
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03HHOLOGRAPHIC PROCESSES OR APPARATUS
    • G03H1/00Holographic processes or apparatus using light, infra-red or ultra-violet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
    • G03H1/02Details of features involved during the holographic process; Replication of holograms without interference recording
    • G03H1/024Hologram nature or properties
    • G03H1/0244Surface relief holograms

Abstract

An optically variable device (50, 250, 260) including a plurality of relief elements (60, 251, 261, 262) applied to a surface (22). The relief elements (60, 251, 261, 262) collectively generate, by diffraction and/or refraction and/or reflection, an image (202, 203, 204) of a three-dimensional object (201). The relief elements (60, 251, 261, 262) may lie on or near contour lines (222a, 222b, 222c, 222d, 222e) on the surface (22), the contour lines (222a, 222b, 222c, 222d, 222e) corresponding to height and/or depth levels of the object (201).

Description

OPTICALLY VARIABLE DEVICE

FIELD OF THE INVENTION

The present invention relates to optically variable devices. The devices are particularly suitable for use as security features in banknotes and other documents of value, but may also have other application, for example as decorative features.

BACKGROUND TO THE INVENTION

Optically variable devices are commonly used as security features. Such devices often take the form of a diffractive optically variable device (DOVD), which has a distinctive coloured and shimmering or glittering appearance due to the appearance of different diffraction orders for different wavelengths of incident light as the observation or illumination angle is changed.

Other commonly employed devices rely instead on refraction. For example, an array of interlaced portions of a plurality of two-dimensional images located at the foci of an array of lenticular or spherical microlenses can display apparent motion effects as the observation angle is varied. The portions corresponding to each image are visible at different respective observation angles so that an illusion of motion is produced. Refractive devices of this type can also in some cases be made to produce an illusion of depth, by adjusting the focal length so that the resulting image lies outside the plane of the device.

Purely refractive devices of this type have the disadvantage of adding significantly to the thickness of a security document to which they are applied, since the typical thickness of the lenses required to produce the desired effects can be of the order of 50 microns or more, which is also the typical thickness of, for example, a banknote substrate.

SUMMARY OF THE INVENTION

It is therefore desirable to provide an alternative optically variable device which gives an impression of depth to a person viewing the device, but which does not add significantly to the thickness of a document or other article to which the device is applied.

Accordingly, there is provided an optically variable device including a plurality of relief elements applied to a surface, wherein the relief elements collectively generate, by diffraction and/or refraction and/or reflection, an image of a three-dimensional object.

Preferably, the relief elements lie on or near contour lines on the surface, the contour lines corresponding to height and/or depth levels of the object. The contour lines may include open contours corresponding to a two-dimensional surface of the object, the open contours lying on a plane which is at an angle to the surface of the device, so that the image is viewable off-axis. This has the particular benefit of providing an additional immediately recognisable security feature, since a person viewing the device would ordinarily expect the three- dimensional image to appear on-axis, but will not see the image until the device is tilted away from the on-axis position. There may also be increased ease of application of relief elements which follow open rather than closed contours.

The relief elements may include a first group of relief elements which are visible in a first range of observation angles, and a second group of relief elements which are visible in a second, different, range of observation angles.

Preferably, the first and second ranges are sufficiently close together to produce an autostereoscopic effect to the observer.

In one particularly preferred embodiment, the relief elements are segments of diffractive grooves which substantially follow the contours. This has substantial advantages over known diffractive structures, in that when it is desired to produce a three-dimensional effect which is achromatic or which is of a single colour, the segments of the grooves can be modulated so as to reduce or eliminate spurious diffraction effects.

Each segment may have a projected shape on the surface which includes at least one straight edge. The projected shape is preferably substantially polygonal. In some embodiments, the projected shape is a regular polygon.

Alternatively, each segment may have a projected shape on the surface which includes at least one arcuate section. The shape may be substantially circular, part-circular, elliptical or part-elliptical.

The maximum dimension of each relief element is preferably less than 60 microns, and even more preferably less than 1 0 microns. This provides a low- profile relief structure which appears three-dimensional but is two-dimensional to the touch, thereby increasing the recognisability of the device as a security feature.

The projected shapes of the first group of relief elements and the projected shapes of the second group of relief elements may differ. Thus, for example, the two groups may produce different diffractive and/or reflective and/or refractive effects so that a first three-dimensional image appears at one viewing angle whilst a second three-dimensional image appears at another viewing angle.

The spacings between adjacent segments, and/or the dimensions of individual segments, may be modulated in random or pseudo-random fashion in order to ensure that unwanted diffraction orders are not present in the image seen by the observer. Alternatively, the spacings and/or dimensions of the segments may be varied according to a particular predetermined function of the spatial coordinates of the segments, for example a harmonic or periodic function.

As an alternative (or in addition) to modulation of the spacing and/or dimensions of the segments, their positions may be offset from the contours of the image surface by a predetermined distance. The predetermined distance may be modulated in random or pseudo-random fashion, or may vary according to a harmonic or periodic function.

In another preferred embodiment, the spacing between segments and/or the dimensions of the segments may be modulated in at least one region to encode a hidden image. The hidden image may be viewable by transposing a decoding screen on the at least one region, and the decoding screen may be a line screen or dot screen.

In yet another embodiment, the spacing between segments and/or the dimensions of the segments may be modulated so that at least some regions of the device are diffusely scattering. This results in at least part of the image giving a perception of achromatic surface roughness to the observer, and can be advantageous in that it allows for a more realistic impression of a three- dimensional object to be conveyed to an observer.

In one particularly preferred embodiment, the device diffracts light at angles away from the zero-order to produce the image. When the device produces a substantially achromatic image, this provides yet another distinctive security feature, since an observer viewing the security device would ordinarily assume that the image would be visible at or near the angle of specular reflection from the device surface rather than at an oblique angle.

BRIEF DESCRIPTION OF THE DRAWINGS

Certain embodiments of the invention will now be described by reference to the accompanying drawings, in which:

Figures 1 (a) to 1 (c) show security documents including optical security devices which produce apparently three-dimensional images;

Figure 2 shows a three-dimensional object corresponding to one of the images of Figure 1 , a contour map of the three-dimensional object, and diffractive relief elements of an optical security device distributed along the contours in two different ways;

Figure 3 shows a three-dimensional image which is visible on-axis, and the contours and relief elements of the structure producing the image;

Figure 4 shows an alternative to Figure 3 in which the three-dimensional image is produced off-axis; and

Figure 5 shows an alternative embodiment of an optical security device producing a three-dimensional image by stereoscopy.

DESCRIPTION OF PREFERRED EMBODIMENTS

In Figure 1 (a), there is shown a cross-section through a security document 10 including a substrate 20. The substrate 20 may be a transparent or translucent plastics material such as biaxially oriented polyproplylene (BOPP). Opacifying layers 25 are applied to each side of the substrate 20 to facilitate the application of printing, for example the printed elements 15 which form part of a denominator or other indicia. The opacifying layers 25 are omitted on one or both sides of the substrate 20 in regions 28 in order to form a transparent half-window or window region in the security document.

The window or half-window is itself a security feature, but the security of the document is enhanced by the application of a further security device partly or wholly within the window or half-window. For example, in Figure 1 (b), only the top opacifying layer 35 of security document 1 1 is part-omitted, whilst bottom opacifying layer 36 is applied to the entire surface of the substrate 20, so that a half-window 29 is formed. A security device 50 is then applied to the upper surface 22 of the substrate, for example by an embossing method, within the half- window 29. The security device may be applied directly into the substrate, or may be applied to a further layer of material, for example a UV-curable ink or lacquer layer which has been applied to substrate 20 in the half-window region.

Upon illumination of the security device 50 in direction 100, light is diffracted, reflected or refracted in directions 102, 103 from the relief elements 60 of the security device 50 and a person viewing the device in reflection mode (i.e., from the same side of the substrate as the light source) at either of those angles sees an image 202, 203 of a three-dimensional object. Images 202 and 203 could correspond to, for example, non-zero diffraction orders of the security device 50. It is also possible to produce an image in direction 1 00', corresponding to the direction of specular reflection, i.e. a zero-order image.

Alternatively, a security device 52 could be formed in a full window 28 as in Figure 1 (c), in which the opacifying layers 45, 46 are part-omitted on both sides of the substrate 20 in order to form the window region 28. A person viewing the security document 12 containing the security device 52 may then view a three- dimensional image 204 in transmission mode (i.e., from the opposite side of the substrate to the light source). An image (not shown) may be formed in the on-axis direction 1 10, or in an off-axis direction 1 12.

Referring now to Figure 2, three-dimensional object 201 is shown divided up into slices 212a-212e corresponding to different height levels of the object 201. Each slice has a predetermined thickness which is preferably of the order of the wavelength of light which is to be used to illuminate the security device 50.

The three-dimensional object may be a real or imagined (e.g., computer- generated) object.

Each contour 222a-222e of the contour map 230 of the two-dimensional surface of the object 202 corresponds to the base of one of the slices 21 2a-212e. The contour map 230 can be used as a template for the placement of the relief elements 60 on the upper surface 22 of substrate 20. The relief elements 60 may be continuous diffractive grooves following contours 222a-222e, or alternatively may be segmented diffractive, reflective or refractive grooves 251 , 261 , 262.

The segments 251 of the device 250 and segments 261 , 262 of the device 260, shown projected into the plane of the substrate surface 22, are of varying size and spacing. Modulation of the segment spacing and width prevents or greatly reduces the appearance of unwanted diffraction orders in the case where the device is operating by the diffraction process, rather than by reflection or refraction. For example, if a substantially achromatic image appearing in the first order is desired, then it is preferred to ensure that the zero, second, third etc. orders do not contribute to the image to spoil its achromatic appearance.

The segments 251 of device 250 are of substantially polygonal shape (rectangles, rhombi, parallelograms etc), and lie exactly or almost exactly on the contours 222a-222e (contours not shown). In an alternative device 260, the segments 262 may be offset from the contours 222b-222e while other segments 261 lie along contour 222a. The segments may include non-polygonal elements of varying size, for example flattened ellipses 262. The spacings between adjacent segments along a contour may also be modulated as described above.

Referring now to Figures 3(a) to 3(c), there is shown a three-dimensional image 500 lying along a plane 502 and with a surface 501 having the functional form Z = f(x,y) = 0. 125(cos(1.5706x)cos(1.5706y) + 0.667( cos(1.5706x) + cos(1.5706y) ) ) where the x, y and z axes are oriented generally as shown at 510. The surface of the optically variable device is substantially parallel to the x-y plane. A relief structure 520 having a set of relief elements 521 , 522, 523, 524 lying on or near the closed contours 505 of the image produces the on-axis image 500. The relief elements may be diffractive, reflective or refractive and may take various forms, for example part-ellipses 521 , trapezoids 522, part-annuli 523, part-circles 524, etc.

If the surface 501 is rotated through an angle β in the y-z plane as shown in Figure 4(a), the three-dimensional image 550 of the object will appear to the viewer when the device is tilted off-axis by an angle β. The surface now has the functional form Z = f(x,y) = tan$)y +0.125(cos(1.5706x)cos(1.5706y) + 0.667( cos(1.5706x) + cos(i.5706y) ) ). The open contours 555 on the surface of the device along which the relief elements should be placed to produce such an image are shown in Figure 4(b). The corresponding relief elements may be of various shapes and sizes as shown in Figure 4(c), for example trapezoids 561 , parallelograms 562 and so on. Some of the relief elements are offset by a small distance relative to the corresponding contour line in order to reduce the effect of parasitic diffraction on image brightness and achromaticity. For example, relief elements 571 , 572, 573 and 574 are each offset relative to contour line 570.

Figure 5 shows an alternative embodiment in which optical security device 600 is illuminated by light source 610. A first group of relief elements 621 diffracts, reflects or refracts light in a first direction 61 1 which is seen by the left eye 601 of an observer. Likewise, light is diffracted, reflected or refracted in a second direction 612 by a second group 622 of relief elements to be observed by the right eye 602. The difference in viewing angles 61 1 , 61 2 is small so that the net effect of diffractive structures 621 , 622 is an autostereoscopic one, giving the observer the impression that the portion of the combined image being viewed is located at a point 640 located outside the plane 650 of the device 600. Similarly, other regions of relief elements (not shown) produce a stereoscopic effect at different points to reconstruct the surface of an apparently three-dimensional object 630.

It will be recognised that various modifications to the above-described embodiments are possible. For example, the two groups 621 , 622 could be made to produce images at substantially the same observation angle, but with different polarisations, for example left- and right-handed circular polarisations or two different linear polarisations. A person viewing the device through a pair of glasses, the lenses of which act as polarisation filters for the two different polarisations, could then observe a three-dimensional effect by virtue of stereoscopy (rather than autostereoscopy).

Claims

CLAIMS:
1 . An optically variable device including a plurality of relief elements applied to a surface, wherein the relief elements collectively generate, by diffraction and/or refraction and/or reflection, an image of a three-dimensional object.
2. An optically variable device according to claim 1 , wherein the relief elements lie on or near contour lines on the surface, the contour lines corresponding to height and/or depth levels of the object.
3. An optically variable image according to claim 2, wherein the contour lines include open contours corresponding to a two-dimensional surface of the object, the open contours lying on a plane which is at an angle to the surface of the device, so that the image is viewable off-axis.
4. An optically variable device according to any one of the preceding claims, wherein the relief elements include a first group of relief elements which are visible in a first range of observation angles, and a second group of relief elements which are visible in a second, different, range of observation angles.
5. An optically variable device including a plurality of relief elements applied to a surface, wherein the relief elements include a first group of relief elements which are visible in a first range of observation angles, and a second group of relief elements which are visible in a second, different, range of observation angles, the relief elements collectively generating, by diffraction and/or refraction and/or reflection, an image of a three-dimensional object.
6. An optically variable device according to claim 4 or claim 5, wherein the first and second ranges are sufficiently close together to produce an autostereoscopic effect to the observer.
7. An optically variable device according to any one of claims 2 to 4, or according to claim 6 appended to claim 4, wherein the relief elements are segments of diffractive grooves which substantially follow the contour lines.
8. An optically variable device including a plurality of relief elements applied to a surface, the relief elements collectively generating, by diffraction and/or refraction and/or reflection, an image of a three-dimensional object, wherein the relief elements are segments of diffractive grooves, the segments lying on or near contour lines on the surface which correspond to height and/or depth levels of the object.
9. An optically variable device according to claim 8, wherein each segment has a projected shape on the surface which includes at least one straight edge.
10. An optically variable device according to claim 9, wherein the projected shape is substantially polygonal.
1 1 . An optically variable device according to claim 1 0, wherein the projected shape is a regular polygon.
12. An optically variable device according to claim 8, wherein each segment has a projected shape on the surface which includes at least one arcuate section.
13. An optically variable device according to claim 1 2, wherein the projected shape is substantially circular, part-circular, elliptical or part-elliptical.
14. An optically variable device according to any one of the preceding claims, wherein the maximum dimension of each relief element is less than 60 microns.
15. An optically variable device according to any one of claims 7 to 14 when appended to claim 4 or claim 5, wherein the projected shapes of the first group of relief elements and the projected shapes of the second group of relief elements are different.
16. An optically variable device according to any one of claims 7 to 15, wherein the spacing between segments and/or the dimensions of the segments are modulated in random or pseudo-random fashion.
17. An optically variable device according to any one of claims 7 to 15, wherein the spacing between segments and/or the dimensions of the segments are modulated according to a harmonic or periodic function.
18. An optically variable device according to any one of claims 7 to 15 when appended to claim 2 or claim 3, wherein the segments are offset from the contour lines by a predetermined distance.
19. An optically variable device according to any one of claims 16 to 1 8, wherein the spacing between segments and/or the dimensions of the segments are modulated in at least one region to encode a hidden image.
20. An optically variable device according to claim 19, wherein the hidden image is viewable by transposing a decoding screen on the at least one region.
21 . An optically variable device according to claim 20, wherein the decoding screen is a line screen or dot screen.
22. An optically variable device according to any one of claims 16 to 18, wherein the spacing between segments and/or the dimensions of the segments are modulated so that at least some regions of the device are diffusely scattering, whereby at least part of the image gives a perception of achromatic surface roughness to the observer.
23. An optically variable device according to any one of the preceding claims, wherein the device diffracts light at angles away from the zero-order to produce the image.
24. An article including the optically variable device of any one of claims 1 to 23.
25. An article according to claim 24, wherein the article is a security document.
26. An article according to claim 25, wherein the optically variable device is applied at least partly in a window or half-window region of the security document.
PCT/AU2010/001672 2010-01-04 2010-12-13 Optically variable device WO2011079347A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
AU2010900012A AU2010900012A0 (en) 2010-01-04 Optically variable device
AU2010900012 2010-01-04

Publications (1)

Publication Number Publication Date
WO2011079347A1 true WO2011079347A1 (en) 2011-07-07

Family

ID=44203225

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2010/001672 WO2011079347A1 (en) 2010-01-04 2010-12-13 Optically variable device

Country Status (3)

Country Link
FR (1) FR2954978A1 (en)
MT (1) MTP4294B (en)
WO (1) WO2011079347A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013007374A1 (en) * 2011-07-14 2013-01-17 Giesecke & Devrient Gmbh Visually variable element, in particular a security element for a data medium
DE102013001734A1 (en) 2013-01-31 2014-07-31 Giesecke & Devrient Gmbh Security element with channel or rib-shaped structural elements
WO2014152119A1 (en) 2013-03-15 2014-09-25 Opsec Security Group, Inc. Variable device exhibiting non-diffractive three-dimensional optical effect
EP2955564A1 (en) 2014-06-13 2015-12-16 API Holographics Optically variable element
DE102017106433A1 (en) 2017-03-24 2018-09-27 Ovd Kinegram Ag Security element and method for producing a security element

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5105306A (en) * 1989-01-18 1992-04-14 Ohala John J Visual effect created by an array of reflective facets with controlled slopes
WO2002091041A1 (en) * 2001-05-08 2002-11-14 Commonwealth Scientific And Industrial Research Organisation An optical device and methods of manufacture
WO2006013215A1 (en) * 2004-08-06 2006-02-09 Optaglio Sro A method of creating a three-dimensional image, a diffractive element and method of creating the same
US20060056065A1 (en) * 2002-11-22 2006-03-16 Ovd Kinegram Ag Optically variable element and the use thereof
US20100045024A1 (en) * 2007-02-07 2010-02-25 Leonhard Kurz Stiftung & Co. Kg Security element for a security document and process for the production thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5105306A (en) * 1989-01-18 1992-04-14 Ohala John J Visual effect created by an array of reflective facets with controlled slopes
WO2002091041A1 (en) * 2001-05-08 2002-11-14 Commonwealth Scientific And Industrial Research Organisation An optical device and methods of manufacture
US20060056065A1 (en) * 2002-11-22 2006-03-16 Ovd Kinegram Ag Optically variable element and the use thereof
WO2006013215A1 (en) * 2004-08-06 2006-02-09 Optaglio Sro A method of creating a three-dimensional image, a diffractive element and method of creating the same
US20100045024A1 (en) * 2007-02-07 2010-02-25 Leonhard Kurz Stiftung & Co. Kg Security element for a security document and process for the production thereof

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013007374A1 (en) * 2011-07-14 2013-01-17 Giesecke & Devrient Gmbh Visually variable element, in particular a security element for a data medium
CN103648791A (en) * 2011-07-14 2014-03-19 德国捷德有限公司 Visually variable element, in particular a security element for a data medium
AU2012283462B2 (en) * 2011-07-14 2016-01-28 Giesecke+Devrient Currency Technology Gmbh Visually variable element, in particular a security element for a data medium
DE102013001734A1 (en) 2013-01-31 2014-07-31 Giesecke & Devrient Gmbh Security element with channel or rib-shaped structural elements
WO2014117938A1 (en) 2013-01-31 2014-08-07 Giesecke & Devrient Gmbh Security element comprising groove or rib-shaped structural elements
US10005309B2 (en) 2013-01-31 2018-06-26 Giesecke+Devrient Currency Technology Gmbh Security Element Having Groove- or Rib-Shaped Structural Elements
WO2014152119A1 (en) 2013-03-15 2014-09-25 Opsec Security Group, Inc. Variable device exhibiting non-diffractive three-dimensional optical effect
EP2972563A4 (en) * 2013-03-15 2016-11-02 Opsec Security Group Inc Variable device exhibiting non-diffractive three-dimensional optical effect
EP2955564A1 (en) 2014-06-13 2015-12-16 API Holographics Optically variable element
DE102017106433A1 (en) 2017-03-24 2018-09-27 Ovd Kinegram Ag Security element and method for producing a security element

Also Published As

Publication number Publication date
FR2954978A1 (en) 2011-07-08
MTP4294B (en) 2011-09-01

Similar Documents

Publication Publication Date Title
RU2478998C9 (en) Image reproducing system and microoptic security system
US8254030B2 (en) Micro-optic security and image presentation system presenting a synthetically magnified image that appears to lie below a given plane
TWI377134B (en) Sicherheitsdokument
TWI441744B (en) Multi-layer body with micro-lens arrangement
ES2434443T3 (en) Imaging system and micro-optical security
RU2255000C1 (en) Protective element
EP1709467B1 (en) Backlight for 3d display device
US8957761B2 (en) Display and labeled article
AU2006230761B2 (en) Patterned optical structures with enhanced security feature
CA2780458C (en) Security element, value document having such a security element, and manufacturing method for a security element
AU2010327031B2 (en) Security element, value document comprising such a security element, and method for producing such a security element
JP5937522B2 (en) Moire expansion element
EP2162294B1 (en) Security element
EP2164711B1 (en) Representation system
RU2358317C2 (en) Optical protective element
KR100905833B1 (en) Security Element With Diffraction Structures
JP5157121B2 (en) Display and printed matter
US5032003A (en) Optially variable surface pattern
US10473831B2 (en) Display having light-scattering property
JP2010052437A (en) Indicator and information printed matter
JP5350273B2 (en) Security element
US20130069360A1 (en) Security document with integrated security device and method of manufacture
RU2344480C2 (en) Optical protective element and system for visualisation of hidden information
JP2016531022A (en) Security device and manufacturing method thereof
DE10129939B4 (en) Optically variable surface pattern

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10840226

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10840226

Country of ref document: EP

Kind code of ref document: A1