NZ516254A - Security article including diffractive optic filter - Google Patents
Security article including diffractive optic filterInfo
- Publication number
- NZ516254A NZ516254A NZ516254A NZ51625400A NZ516254A NZ 516254 A NZ516254 A NZ 516254A NZ 516254 A NZ516254 A NZ 516254A NZ 51625400 A NZ51625400 A NZ 51625400A NZ 516254 A NZ516254 A NZ 516254A
- Authority
- NZ
- New Zealand
- Prior art keywords
- zone
- security
- security article
- diffractive
- substrate
- Prior art date
Links
- 239000000758 substrate Substances 0.000 claims abstract description 25
- 230000003595 spectral effect Effects 0.000 claims abstract description 19
- 229920003023 plastic Polymers 0.000 claims abstract description 8
- 239000000463 material Substances 0.000 claims description 10
- 239000003086 colorant Substances 0.000 claims description 6
- JGFZNNIVVJXRND-UHFFFAOYSA-N N,N-Diisopropylethylamine (DIPEA) Chemical compound CCN(C(C)C)C(C)C JGFZNNIVVJXRND-UHFFFAOYSA-N 0.000 claims description 5
- 239000010410 layer Substances 0.000 description 11
- 239000000976 ink Substances 0.000 description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 235000020280 flat white Nutrition 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/40—Manufacture
- B42D25/405—Marking
- B42D25/41—Marking using electromagnetic radiation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/20—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof characterised by a particular use or purpose
- B42D25/29—Securities; Bank notes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/30—Identification or security features, e.g. for preventing forgery
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/20—Filters
- G02B5/203—Filters having holographic or diffractive elements
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B42—BOOKBINDING; ALBUMS; FILES; SPECIAL PRINTED MATTER
- B42D—BOOKS; BOOK COVERS; LOOSE LEAVES; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITY FEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOT OTHERWISE PROVIDED FOR; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDED FOR; MOVABLE-STRIP WRITING OR READING APPARATUS
- B42D25/00—Information-bearing cards or sheet-like structures characterised by identification or security features; Manufacture thereof
- B42D25/30—Identification or security features, e.g. for preventing forgery
- B42D25/328—Diffraction gratings; Holograms
Landscapes
- Physics & Mathematics (AREA)
- General Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Business, Economics & Management (AREA)
- Accounting & Taxation (AREA)
- Finance (AREA)
- Health & Medical Sciences (AREA)
- Optics & Photonics (AREA)
- General Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Credit Cards Or The Like (AREA)
- Inspection Of Paper Currency And Valuable Securities (AREA)
- Diffracting Gratings Or Hologram Optical Elements (AREA)
- Holo Graphy (AREA)
Abstract
A security article such as banknotes, credit cards, passports, security passes, etc. comprising a transparent plastics substrate (2) bearing a diffractive optic filter (6) comprising at least a first zone (7) and second zone (8), with first and second diffractive structures or gratings formed in each zone. The first diffractive structure being operative to discriminatingly project a first selected colour at a first selected colour at a viewing angle by diffracting at least a first spectral component (e.g. red and green) of polychromatic light transmitted through said first zone by at least an angle theta from said viewing angle, said first colour forming at least part of a projected security image when said diffractive optic filter is viewed at said viewing angle.
Description
<div class="application article clearfix" id="description">
<p class="printTableText" lang="en">PCT/AU00/00723 Received 31 July 2001 <br><br>
CORRECTED VERSION <br><br>
1 <br><br>
SECURITY ARTICLE INCLUDING DIFFRACTIVE OPTIC FILTER <br><br>
The present invention relates generally to devices for authenticating various items which are subject to counterfeiting, and in particular to authenticating devices of this type which act to diffract incident light. The invention is suitable for use with banknotes and other security documents such as credit cards, passports, security passes, etc., and it will be convenient to hereinafter describe the invention in relation to that exemplary application. It is to be appreciated, however, that the invention is not limited to use in this application. <br><br>
A wide variety of security devices or features for security documents, <br><br>
such as banknotes, travellers' cheques or the like have been proposed previously. Examples of such security devices and features include optically variable devices such as holograms and diffraction gratings, security threads or strips, micro-print, fine line or "filigree" patterns, moire inducing patterns and optically variable inks. <br><br>
However, recently considerable advances have been made in photocopying and like machines for the colour reproduction of documents. The advances in such machines, and in the technology associated with like equipment enabling the reproduction of banknotes and other security documents, increasingly diminishes the effectiveness of known security devices. <br><br>
Accordingly, there is a need to provide security devices or features for incorporation in security articles or documents of increasing sophistication in order to make unauthorised reproduction of such objects increasingly difficult. <br><br>
A security article comprising a transparent substrate bearing a diffractive optic filter comprising: <br><br>
at least a first zone and a second zone, and a first and second diffractive structure respectively formed in the first and second zones, <br><br>
AMENDED SHEE <br><br>
IPEA/AU <br><br>
PCT/AU00/00723 <br><br>
Received 31 July 2001 <br><br>
CORRECTED VERSION <br><br>
2 <br><br>
the first diffractive structure being operative to discriminatingly project a first selected colour at a viewing angle by diffracting at least a first spectral component of polychromatic light transmitted through the first zone by an 0 from the viewing angle, <br><br>
the second diffractive structure being operative to discriminatingly project a second selected colour at the viewing angle by diffracting at least a second spectral component of polychromatic light transmitted through the second zone by the angle 0 from the viewing angle, <br><br>
the first and second colours together form at least part of a projected security image when the security article is viewed from the viewing angle. <br><br>
In one embodiment, the substrate is formed of transparent plastics material. The transparent plastic substrate may comprise at least one film of transparent polymeric material. <br><br>
An opacifying layer may be applied to at least a first surface of a substrate, said opacifying layer only partly covering said first surface of the substrate to leave at least said diffractive optic filter essentially uncovered. The substrate may include an uncovered region at least partially surrounding said diffractive optic filter. <br><br>
The security article may be a security document, such as a banknote. <br><br>
The following description refers in more detail to the various features of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the security article is illustrated in a preferred embodiment. It is to be understood that the security article of the present invention is not, however, limited to that preferred embodiment. <br><br>
In the drawings: <br><br>
Figure 1 is a plan view of a banknote in accordance with one embodiment of the invention; <br><br>
AMENDED 8HB-* <br><br>
IPEA/AU <br><br>
PCT/AUOO/00723 <br><br>
Received 31 July 2001 <br><br>
CORRECTED VERSION <br><br>
2a <br><br>
Figure 2 is a schematic diagram illustrating the operation of the diffractive optic filter of the banknote of Figure 1 in the presence of incident polychromatic light; and <br><br>
Figure 3 is a schematic diagram illustrating the projection of a security image by the diffractive optic filter of the banknote of Figure 1. <br><br>
Referring now to Figure 1, there is shown generally a banknote 1, being one example of a security article according to the present invention. The banknote 1 has a substantially planar structure and comprises a flexible sheetlike substrate 2 of transparent plastics material. The substrate 2 is covered over most of its upper and <br><br>
AMENDED SHEET <br><br>
IPEA/AU <br><br>
WO 01/02192 PCT/AUO0/00723 <br><br>
3 <br><br>
lower surfaces by opacifying layers 3 and 4. As shown in Figure 1, the opacifying layers are not applied over the entire surfaces of the sheet-like substrate 2, and thus leave a transparent portion 5 of the substrate which is at least partially uncovered by the opacifying layers 3 and 4. This transparent, essentially uncovered portion 5 5 constitutes a "window" in the banknote through which light may be transmitted <br><br>
The substrate 2 of transparent plastics material is preferably formed from a transparent polymeric material which may be made from at least one biaxially oriented film. The substrate may comprise a single layer film of polymeric material. Alternatively, the substrate may comprise a laminate of two or more 10 layers of transparent biaxially oriented polymeric film. <br><br>
The opacifying layers 3 and 4 may comprise in one or more of a variety of opacifying inks which can be used in the printing of banknotes or security documents. For example, the layers of opacifying ink may comprise pigmented coatings comprising a pigment, such as titanium dioxide dispersed within a binder 15 or carrier of heat activated cross-linkable polymeric material. Alternatively, a substrate of transparent plastics material 2 may be sandwiched between opacifying layers of paper to which indicia is printed or otherwise applied. <br><br>
Whilst the banknote in Figure 1 is shown as having opacifying layers applied to both upper and lower surfaces, in other embodiments of the invention, only one 20 of the surfaces of the banknote may have an opacifying layer applied thereto. <br><br>
According to the present invention, the transparent substrate 2 bears a diffractive optic filter 6. The diffractive optic filter may be incorporated into the surface of the substrate 2, or may be formed within a transfer foil structure that is later applied to the substrate 2. The diffractive optic filter comprises a first zone 7, 25 and, in this example, at least a second zone 8. A diffractive structure is formed in each of the first and second zones 7 and 8. More specifically, each region incorporates a transmissive diffractive structure, such as a diffraction grating, formed as a microscopic 3-D relief pattern. The grating structures of both the first diffractive structure formed in the first zone 7 and the second diffractive structure 30 formed in the second zone 8 have profiles and line spacings, or a periodicity, chosen so as to diffract at least a first spectral component of polychromatic light transmitted <br><br>
WO 01/02192 <br><br>
PCT/AUOO/00723 <br><br>
through the transmissive diffractive structure by a given angle 0. The characteristics of each of the diffractive structures in the two zones 7 and 8 are chosen so that different spectral components of the polychromatic light transmitted by each through the window in the banknote 1 are diffracted, so that the remaining 5 undiffracted spectral component projected by each of the diffractive structures produces visually discernible colours which together form a projected security image. <br><br>
The characteristics of each of the diffractive structures in the first and second zones 7 and 8, such as the line spacing, profile and depth of the grating structure, 10 may be chosen to precisely define that spectral component of the polychromatic light which is to be diffracted. <br><br>
Whilst the embodiment of the security article shown in Figure 1 includes a diffractive optic filter having two zones, each of which includes a different diffractive structure, in other embodiments of the invention only one such zone 15 having a single diffractive structure may be used. Similarly, three or more zones, each having a separate diffractive structure, may be incorporated in other embodiments. <br><br>
Figures 2 and 3 shown one example in which the authenticity of the banknote 1 may be verified by a user. As seen in Figure 2, a user may place the banknote 1 20 directly in front of an appropriate polychromatic light source. For example, the banknote 1, containing the diffractive optic filter in the clear window 5 thereof, may be placed against a video display terminal (VDT) screen 10. The VDT screen contains an array of red, green and blue (RGB) pixels, which respectively transmit a red, green and blue spectral component of the polychromatic light emitted from the 25 screen. <br><br>
In other embodiments, a different polychromatic light source may be used, such as a broad flat white light source such as a fluorescent light box. Preferably the light source used will cover an area which is larger than the area of the diffractive optic filter, and will produce light that can be separated into at least two 30 spectral components. <br><br>
WO 01/02192 PCT/AU00/00723 <br><br>
5 <br><br>
The banknote 1 itself may also act as the polychromatic light source. For example, the banknote 1 may be folded so that a multi-coloured surface is superposed with the clear window 5. Ambient light may then be reflected from the multi-coloured surface of the banknote 1 and transmitted through the diffractive 5 optic filter 6 in the clear window 5. <br><br>
In the configuration shown in Figure 2, the light emanating from the light source 10 passes outwards towards a user 11 situated at a viewing angle from the banknote 1, in this case perpendicular to the plane of the banknote. <br><br>
In this example, the first diffractive structure formed in the first zone 7 of the 10 diffractive optic filter 5 acts to diffract the red and green spectral components of the polychromatic light transmitted through the substrate 2 of the banknote 1, and then through the first zone 7. The characteristics of the first diffractive structure are chosen such that the red and green spectral components are diverted by at least an angle 0 similarly, the second diffractive structure formed in the second zone 8 of the 15 diffractive optic filter 6 acts to diffract the green and blue spectral components of the polychromatic light emitted from the VDT screen 10 by at least the angle 6. <br><br>
Accordingly, only the blue spectral component of the light emitted from the VDT screen is transmitted to the user 11 through the first zone 7, whilst only the red spectral component of the polychromatic from the VDT screen 10 is transmitted by 20 the second zone 8 to the user 11. <br><br>
The colours transmitted by each of the zones of the diffractive optic filter 6 may be chosen so that each transmits a colour which is visually discernible from the colours in each of the other zones. In this way, the colours from the various zones of the diffractive optic filter combine to form at least part of a projected security 25 (schematically represented in Figures 1, 2 and 3 in the form of an "S"). <br><br>
As may be best appreciated from Figure 3, the angle 0 by which the different spectral components of polychromatic light are diffracted by each of the first and second diffractive structures, should be chosen so that the diffracted spectral components are diverted outside of the users field of view 12. <br><br>
30 Referring again to Figure 1, an uncovered zone 13 may be left around at least part of the diffractive optic filter 6 in the window 5, this uncovered portion 13 <br><br>
WO 01/02192 PCT/AU00/00723 <br><br>
6 <br><br>
allowing all spectral components of the polychromatic light emitted from VDT screen 10 to be transmitted to the user 11. This enables the user 11 to more easily distinguish between the unfiltered light transmitted through the uncovered portion 13 and that transmitted through the diffractive optic filter 6. <br><br>
Many other variations may be made to the above described embodiment without departing from the spirit or ambit of the invention. <br><br>
PCf7AUOO/00723 <br><br>
Received 31 July 2001 <br><br>
7 CORRECTED VERSION <br><br></p>
</div>
Claims (6)
1. A security article comprising a transparent substrate bearing a diffractive optic filter comprising:<br><br> at least a first zone and a second zone, and<br><br> 5 a first and second diffractive structure respectively formed in the first and second zones,<br><br> the first diffractive structure being operative to discriminatingly project a first selected colour at a viewing angle by diffracting at least a first spectral component of polychromatic light transmitted through the first zone by an angle 10 0 from the viewing angle,<br><br> the second diffractive structure being operative to discriminatingly project a second selected colour at the viewing angle by diffracting at least a second spectral component of polychromatic light transmitted through the second zone by the angle 0 from the viewing angle,<br><br> 15 the first and second colours together form at least part of a projected security image when the security article is viewed from the viewing angle.<br><br>
2. A security article according to claim 1, wherein the substrate is formed of transparent plastics material.<br><br> 20<br><br>
3. A security article according to claim 2, wherein the transparent plastic substrate comprises at least one film of transparent polymeric material.<br><br>
4. A security article according to any one of the preceding claims, and 25 further comprising an opacifying layer applied to at least a first surface of a<br><br> AMENDED SHEEl<br><br> IPEA/AU<br><br> PCT/AU00/00723 Received 31 July 2001<br><br> CORRECTED VERi^.<br><br> 8<br><br> substrate, said opacifying layer only partly covering said first surface of the substrate to leave at least said diffractive optic filter essentially uncovered.<br><br>
5. A security article according to claim 4, wherein the substrate includes an uncovered region at least partially surrounding said diffractive optic filter.<br><br>
6. A security article according to any one of the preceding claims, wherein said security article is a security document, such as a banknote.<br><br> AMENDED SH Efc<br><br> IPEA/AU<br><br> </p> </div>
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AUPQ1288A AUPQ128899A0 (en) | 1999-06-30 | 1999-06-30 | Security article including diffractive optic filter |
PCT/AU2000/000723 WO2001002192A1 (en) | 1999-06-30 | 2000-06-26 | Security article including diffractive optic filter |
Publications (1)
Publication Number | Publication Date |
---|---|
NZ516254A true NZ516254A (en) | 2002-05-31 |
Family
ID=3815477
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NZ516254A NZ516254A (en) | 1999-06-30 | 2000-06-26 | Security article including diffractive optic filter |
Country Status (9)
Country | Link |
---|---|
EP (1) | EP1240031A1 (en) |
JP (1) | JP2003503759A (en) |
KR (1) | KR20020022729A (en) |
CN (1) | CN1359340A (en) |
AU (1) | AUPQ128899A0 (en) |
CA (1) | CA2376463A1 (en) |
NZ (1) | NZ516254A (en) |
TW (1) | TW567146B (en) |
WO (1) | WO2001002192A1 (en) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7052762B2 (en) | 2001-05-24 | 2006-05-30 | 3M Innovative Properties Company | Low Tg multilayer optical films |
DE10254500B4 (en) * | 2002-11-22 | 2006-03-16 | Ovd Kinegram Ag | Optically variable element and its use |
US7655296B2 (en) | 2003-04-10 | 2010-02-02 | 3M Innovative Properties Company | Ink-receptive foam article |
US7820282B2 (en) | 2003-04-10 | 2010-10-26 | 3M Innovative Properties Company | Foam security substrate |
DE102004003984A1 (en) * | 2004-01-26 | 2005-08-11 | Giesecke & Devrient Gmbh | Lattice image with one or more grid fields |
AU2006257720B2 (en) * | 2005-06-17 | 2010-12-02 | Securency International Pty Ltd | Security documents incorporating colour shifting inks |
GB2441261B (en) * | 2005-06-17 | 2009-05-27 | Securency Pty Ltd | Security documents incorporating colour shifting inks |
GB0613306D0 (en) | 2006-07-04 | 2006-08-16 | Rue De Int Ltd | Security device |
DE202010008331U1 (en) | 2010-08-23 | 2011-11-29 | Tremco Illbruck Produktion Gmbh | Foam sealing tape |
CN102542313B (en) * | 2012-01-05 | 2015-04-15 | 苏州大学 | Double-channel grating structure, identification structure and card identification method |
DE102012010908A1 (en) * | 2012-06-01 | 2013-12-05 | Giesecke & Devrient Gmbh | Verification of value documents with a window with diffractive structures |
DE102012108169A1 (en) | 2012-09-03 | 2014-05-28 | Ovd Kinegram Ag | Security element as well as security document |
CN106457875B (en) * | 2014-05-16 | 2019-10-25 | 尤尼卡技术股份有限公司 | The data medium of authentication feature with personalizable |
CN107633596A (en) * | 2017-08-14 | 2018-01-26 | 深圳怡化电脑股份有限公司 | A kind of method, apparatus and storage medium for identifying bank card |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3248989T1 (en) * | 1981-08-24 | 1984-04-05 | Commonwealth Scientific And Industrial Research Organization, Campbell | Improved banknotes and the like |
US5876068A (en) * | 1988-03-04 | 1999-03-02 | Gao Gessellschaft Fur Automation Und Organisation Gmbh | Security element in the form of a thread or strip to be embedded in security documents and methods of producing it |
DE4343387A1 (en) * | 1993-12-18 | 1995-06-29 | Kurz Leonhard Fa | Visually identifiable, optical security element for documents of value |
GB2296784A (en) * | 1995-01-07 | 1996-07-10 | Debden Security Printing Ltd | A method of forming a composite image & a lamina for use in the method |
AUPO384796A0 (en) * | 1996-11-26 | 1996-12-19 | Commonwealth Scientific And Industrial Research Organisation | Colour image diffractive device |
-
1999
- 1999-06-30 AU AUPQ1288A patent/AUPQ128899A0/en not_active Abandoned
-
2000
- 2000-06-26 CN CN00809818A patent/CN1359340A/en active Pending
- 2000-06-26 JP JP2001507657A patent/JP2003503759A/en active Pending
- 2000-06-26 WO PCT/AU2000/000723 patent/WO2001002192A1/en not_active Application Discontinuation
- 2000-06-26 KR KR1020017016742A patent/KR20020022729A/en not_active Application Discontinuation
- 2000-06-26 NZ NZ516254A patent/NZ516254A/en unknown
- 2000-06-26 EP EP00940019A patent/EP1240031A1/en not_active Withdrawn
- 2000-06-26 CA CA002376463A patent/CA2376463A1/en not_active Abandoned
- 2000-06-29 TW TW089112871A patent/TW567146B/en not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
JP2003503759A (en) | 2003-01-28 |
EP1240031A1 (en) | 2002-09-18 |
WO2001002192A1 (en) | 2001-01-11 |
AUPQ128899A0 (en) | 1999-07-22 |
KR20020022729A (en) | 2002-03-27 |
TW567146B (en) | 2003-12-21 |
CA2376463A1 (en) | 2001-01-11 |
CN1359340A (en) | 2002-07-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
AU723787B2 (en) | Security device | |
EP0935535B1 (en) | Banknotes incorporating security devices and method of producing the same | |
KR101399482B1 (en) | Improvements in substrates | |
US7976068B2 (en) | Double-blind security features | |
US7429062B2 (en) | Anti-counterfeiting see-through moire security feature using frequency-varying patterns | |
NZ516254A (en) | Security article including diffractive optic filter | |
US20180178578A1 (en) | Optical device having a hidden depiction | |
WO2006133512A1 (en) | Security documents incorporating colour shifting inks | |
CA2578012C (en) | Security document with a volume hologram forming a partial motif | |
CA3095257A1 (en) | Optical device and method of manufacture thereof | |
US20230347679A1 (en) | Security devices and method of manufacture thereof | |
US20220144006A1 (en) | Security device and method of manufacture thereof | |
AU5510100A (en) | Security article including diffractive optic filter | |
AU2015100789A4 (en) | Optical Device having a Hidden Depiction | |
GB2604011A (en) | Security device and method of manufacture thereof | |
JP2003305793A (en) | Laminate having watermarked pattern discernible between truth and falsehood |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PSEA | Patent sealed | ||
RENW | Renewal (renewal fees accepted) |