WO1993022746A1 - Optically variable coins, medals, tokens and other non-fibrous articles and method for making same - Google Patents
Optically variable coins, medals, tokens and other non-fibrous articles and method for making same Download PDFInfo
- Publication number
- WO1993022746A1 WO1993022746A1 PCT/CA1993/000180 CA9300180W WO9322746A1 WO 1993022746 A1 WO1993022746 A1 WO 1993022746A1 CA 9300180 W CA9300180 W CA 9300180W WO 9322746 A1 WO9322746 A1 WO 9322746A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- thin film
- optically variable
- film system
- substrate
- variable thin
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G07—CHECKING-DEVICES
- G07F—COIN-FREED OR LIKE APPARATUS
- G07F1/00—Coin inlet arrangements; Coins specially adapted to operate coin-freed mechanisms
- G07F1/06—Coins specially adapted to operate coin-freed mechanisms
-
- A—HUMAN NECESSITIES
- A44—HABERDASHERY; JEWELLERY
- A44C—PERSONAL ADORNMENTS, e.g. JEWELLERY; COINS
- A44C21/00—Coins; Emergency money; Beer or gambling coins or tokens, or the like
Definitions
- the present invention relates to coins, medals, tokens, and precious metals and other non-fibrous articles protected against counterfeiting and forgery by optically variable multilayer coatings and the method for making the same.
- Baird et. al. in US. Pat. No. 3, 858, 977 teach an optical interference means for the protection of paper currency, valuable papers and identification documents.
- the interference coating consists of thin film layers of suitable thicknesses and materials and provides specific spectral reflectance or transmittance characteristics. Because of the iridescent nature of optical thin films, the observed reflected or transmitted colors change with angle of viewing. These color changes are easily recognized by consumers. Because the process of applying such thin films is complex and requires expensive equipment, articles bearing such devices are difficult to counterfeit.
- optically variable thin films can be prepared by physical vapor deposition onto flexible plastic substrates treated with special release coatings- These thin films are then transferred onto selected areas of the articles to be protected.
- a special flexible cement has to be used.
- Identification documents can be encapsulated in special pouches. In both cases devices produced in this way have a life time that is sufficient for these particular applications.
- An object of the invention is therefore to provide a method to inhibit the counterfeiting of coins, medals, tokens, and precious metals and other non-fibrous articles and thus permit the issuance of higher valued articles of this kinds. In the case of coins this would allow the face value of the coin currency to be increased.
- Another objects of the invention is to provide mechanical and environmental protection of the articles and thus to extend their life.
- an authenticated substrate made of a non-fibrous material having at least one generally planar surface and an optically variable thin film system deposited directly onto the whole or part of the at least one surface of said substrate, said optically variable thin film system changing colors with changing angles of incident light and consisting of at least two thin film layers made of dielectric, semiconducting or metallic materials, one of said at least two layers acting as an adhesive to bond securely said optically variable thin film system to said substrate, said optically variable thin film system being possibly subjected to an annealing process to enhance the durability and hardness of said optically variable thin film system.
- a method of authenticating a substrate made of non-fibrous material with an optically variable thin film system constituted of a plurality of optical thin film layers comprising the steps of: applying at least one optical thin film layer of light absorbing material on a surface of said substrate; applying at least one optical thin film layer of non-light absorbing material on top of said layer of light absorbing material whereby said layer of light absorbing material acts as an adhesive between said surface for said nonlight absorbing material and providing a base color, said light and non-light absorbing optical thin film layers forming a filter, said filter changing colors with changing angles of incident light; and subjecting said optically variable thin film system to an annealing process to enhance the durability and hardness of said optically variable thin film system.
- the outermost layer of the thin film system is a protective layer made of non-light absorbing material and is applied before subjecting the optically variable thin film system to the annealing process, to enhance the durability and hardness of the optically variable thin film system to accommodate stamping of the substrate without affecting the optical properties and lifetime of the optically variable thin film system.
- a protective layer made of non-light absorbing material and is applied before subjecting the optically variable thin film system to the annealing process, to enhance the durability and hardness of the optically variable thin film system to accommodate stamping of the substrate without affecting the optical properties and lifetime of the optically variable thin film system. This allows the authentication of the substrate to be readily incorporated into a minting process.
- the present invention provides advantages in that since the optically variable thin film system can be placed on coin currency or other non-fibrous substrates, the monetary value of coin currency can be increased significantly due to the fact that the likelihood of counterfeit coins having such a thin film system thereon is small.
- Figure 1 is a top plan view of a coin having an optically variable thin film system thereon;
- Figure 2 is the cross sectional view of the coin illustrated in Figure 1;
- Figure 3 is an enlarged view of the layer system depicted in Figure 2 showing the individual layers of which it is comprised;
- Figure 4 is the spectral reflectance curve of one particular thin film system of the type illustrated in Figures 1 and 3.
- Figure 5 is a diagram showing the variation of the CIE coordinates with angle of incidence corresponding to the optically variable layer system whose reflectance is shown in Figure 4.
- Figure 1 represents the plan view of a coin 10 to be protected by an optically variable thin film system 12 in accordance with the invention.
- a cross sectional view a-a of the coin is shown in Figure 2A.
- the optically variable thin film system 12 having a color change with angle of viewing is applied to the whole or part of the surface 14 of the substrate 10.
- Figure 2B represents a different embodiment in which an additional optically variable thin film system 18 is applied to the surface 16 of substrate 10.
- the thin film system 18 may be the same as or different from the system 12.
- the optically variable thin film systems 12 and 18 enable individuals to distinguish at glance an authentic coin from a counterfeit one by tilting the coin and observing the color change.
- FIG. 3 A greatly enlarged cross-sectional view of the optically variable thin film system 12 is shown in Figure 3.
- the body of the coin 10 acts as a substrate for the thin film system 12.
- the thin film system 12 consists of layer groups 20, 22 and 24 deposited on top of each other.
- the purpose of layer group 20 is to enhance the adhesion between the surface 14 of the coin 10 and the subsequent layer group 22. This is very important in view of the wear-and-tear that coins are normally exposed to.
- An additional function of group 20 may be to provide a base color for the thin film system 12.
- Layer group 22 consisting of at least one layer, the optional protective layer group 24 and the layer group 20 provide together the required color and color change characteristics.
- the first layer in layer group 20 may be an opaque metal layer that provides the required base color. This layer must also provide a good adhesion between surface 14 and the remaining layers of the thin film system 12. Suitable metals for this purpose are Co, Cr, Ni, Rh and the alloys Inconel and Ni/Cr, etc. If the coin surface 14 is to provide the base color, a transparent adhesive layer must be used. Suitable materials are Al 2 O 3 , SiO 2 , ZrO 2 , etc.
- Group 22 can consist of dielectric materials only, such as Al 2 O 3 , CeO 2 , Hf0 2 , MgF 2 , Nb 2 O 5 , SiO, SiO 2 , Ta ⁇ , TiO 2 , Y 2 O 3 , ZnS, ZrO 2 .
- layer group 22 may contain dielectric layers made of above materials and as well as metals layers made of Ag, Al, Au, Co, Cr, Cu, Ge, Hf, Inconel, Mo, Nb, Ni, NiCr, Pt, Rh, Si, Ta, Te, Ti, W, Yr,
- the second approach usually requires fewer layers to achieve satisfactory color change characteristics but may result in a somewhat less chemically stable system.
- Layer group 24 consists of materials that are mechanically and chemically very stable and provide additional protection for the thin film system. This is especially important if the layers are deposited onto blanks for use in a minting process.
- the number of optical thin film layers in group 22 depends on the desired color properties. Generally, the more layers there are, the more saturated the colors that can be achieved.
- the materials and thicknesses of the individual layers are selected to optimize the performance of the thin film system 12 not only with respect to the optical characteristics but also to minimize the stress. This is required to achieve a mechanically stable system.
- the underlying principles for the design of optically variable thin film systems has been described in detail in the paper by Dobrowolski et al. in Applied Optics Vol. 28, pp. 2702-2717, 1989. Therefore this topic will not be further discussed herein.
- the surface 14 Prior to the deposition of the thin film system 12, the surface 14 must be thoroughly cleaned. This is done with one or more the following: solvents, ultrasound, vacuum, heating, or plasma cleaning techniques. Once the surface 14 is clean, the thin film system is formed one layer at a time.
- the methods for the deposition of the layers may be selected from the following: thermal evaporation by induction or resistance heating, electron-beam or laser evaporation, ion-assisted and ion plating evaporation, AC and DC magnetron sputtering, chemical vapor deposition from a liquid or gaseous phase, etc. Since these techniques are well known in the art and are discussed in the books by Vossen and Kern , entiled "Thin Film Processes", Vol. I and ⁇ , published in 1978 and 1991 by Academic Press of Boston.
- the thin film system 12 may be subjected to an annealing process to enhance the durability and hardness.
- the annealing method may involve one or more of the following processes: heating, compression, plasma treatments or ion assisted techniques.
- the above procedures results in coins with optically variable properties that remain intact for the duration of their lifetime which is typically between 20 and 40 years.
- the annealing process also allows the substrate 10 with the optically variable thin film system 12 on it to be struck or stamped without affecting the optical properties of the thin film system.
- the layer group 20 consists of a single opaque Inconel film-
- the layer group 22 consists of four dielectric layers made of SiO 2 and ZrO 2 . Because the last layer in this group is made of ZrO 2 (a material that is very hard), the optional protective layer group 24 is not necessary.
- Table 1 The specific layer structure is shown in Table 1 below, where the layers numbers correspond to the order of the deposition of the layers on the substrate 10.
- Figure 4 shows the spectral reflectance curve 30 for normal incidence of light of the optically variable thin film system 12 made in accordance with the parameters set out in Table 1. This results in a gold color.
- the standard method of representing colors is with the aid of the Commission Internationale de l'Eclairage (CIE) chromaticity diagrams which are explained in detail, for example, in the book by G. Wyszecki and W.S. Styles entitled “Color Science”, published by John Wiley & Sons, New York 1967.
- the color variation 40 with angle of incidence of the coin 10 is shown in the CIE chromaticity diagram of Figure 5.
- the present invention is not restricted to the thin film layer system presented in
- the present invention allows coins, medals, tokens and other articles made of non- fibrous materials to be authenticated against counterfeiting.
- the face values can be increased with less worry about counterfeiting.
- the optically variable thin film system 12 can be applied to the coin 10 either before or after it is stamped, the coin authentication process can be readily incorporated into the minting process.
- the present invention further provides a protection against mechanical and environmental damage and extends the life of the articles protected.
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Credit Cards Or The Like (AREA)
Abstract
Coins, medals, tokens, precious metals and other non-fibrous articles protected against counterfeiting by the application of optical thin film systems to at least part of one surface are disclosed. The thin film systems have colors that change with angle of viewing which is difficult to reproduce without specialized expensive equipment. The thin film systems consist of two or more layers composed of metallic, dielectric or semiconducting materials with thicknesses chosen to obtain the desired color change effect. In addition, one or more of the layers may be deposited to ensure good adhesion to the substrate and to provide a base spectral reflectance for the thin film system. An optical protective coating can be the outermost layer of the thin film systems. The resulting optically variable coins, medals, tokens or other non-fibrous articles are subjected to an annealing process to enhance their durability and hardness. The thin films produced in accordance with this invention can withstand stamping operations to add relief to the surface to be protected.
Description
Optically Variable Coins, Medals, Tokens and Other Non-fibrous Articles and Method for Making Same
Field of the Invention
The present invention relates to coins, medals, tokens, and precious metals and other non-fibrous articles protected against counterfeiting and forgery by optically variable multilayer coatings and the method for making the same.
Background of the Invention
Many different techniques are used to protect bank notes, valuable papers and identification documents against forgery and counterfeiting. These include the use of intricate engraved designs with water marks and embedded platelets or metal threads and the use of special inks, etc. Many of the above measures cannot be applied to coins, medals, tokens, and precious metals and other non-fibrous consumer goods and articles that are frequently counterfeited.
In the past, coins, medals, tokens and the like have been protected through the use of intricate embossed designs. The use of blanks sandwiched between two thick or thin layers of different metals (US. Pat. No. 4,579,761, and 4, 247, 374 in the name of Rusoe et. al., US. Pat. No. 3,636, 616 to Remning) has also increased the security of coins. Another method used is to manufacture a coin composed of an annular component made of one metal and a central core made of another metal (US. Pat. No. 5,094,922 in the names of Ielpo and Patarini issued in March of 1992).
The above methods have deterred but not eliminated the counterfeiting of coins. As a result, the face values of coins have been kept low, except for collectors' coins which rely on the use of noble metals for their protection. Coins are an attractive method of payment because they can stay in circulation for 20 or 40 years. However, the use of noble metals is not a solution that is viable for mass circulation coinage.
Baird et. al. in US. Pat. No. 3, 858, 977 teach an optical interference means for the protection of paper currency, valuable papers and identification documents. The interference coating consists of thin film layers of suitable thicknesses and materials and provides specific spectral reflectance or transmittance characteristics. Because of the iridescent nature of optical thin films, the observed reflected or transmitted colors change with angle of viewing. These color changes are easily recognized by consumers. Because
the process of applying such thin films is complex and requires expensive equipment, articles bearing such devices are difficult to counterfeit.
Color shifts from red to gold, to green, to blue are possible. Blue-to-red and transparent-to-red color shifts have been described in the paper of Dobrowolski et. al. in App. Opt. Vol. 28, pp. 2702-2717, 1989. Other patents dealing with thin film interference anti-counterfeiting devices have been issued to Be ning et. al. (US. Pat. Nos. 4,705,300; 4,705,356; 4,779, 898 and 4,930,866).
The optically variable thin films can be prepared by physical vapor deposition onto flexible plastic substrates treated with special release coatings- These thin films are then transferred onto selected areas of the articles to be protected. In the case of bank notes, a special flexible cement has to be used. Identification documents can be encapsulated in special pouches. In both cases devices produced in this way have a life time that is sufficient for these particular applications.
Objects of the Invention
The methods developed for the protection of bank notes, valuable papers and identification documents with optically variable thin film devices cannot be directly applied to coins, medals, tokens and other non-fibrous articles. Furthermore, because of the much longer life of these articles, the mechanical and environmental demands on the optical thin film systems for this applications are much more stringent.
An object of the invention is therefore to provide a method to inhibit the counterfeiting of coins, medals, tokens, and precious metals and other non-fibrous articles and thus permit the issuance of higher valued articles of this kinds. In the case of coins this would allow the face value of the coin currency to be increased.
Another objects of the invention is to provide mechanical and environmental protection of the articles and thus to extend their life.
Statement of the Invention
According to one aspect of the present invention there is provided an authenticated substrate made of a non-fibrous material having at least one generally planar surface and an optically variable thin film system deposited directly onto the whole or part of the at least one surface of said substrate, said optically variable thin film system changing colors
with changing angles of incident light and consisting of at least two thin film layers made of dielectric, semiconducting or metallic materials, one of said at least two layers acting as an adhesive to bond securely said optically variable thin film system to said substrate, said optically variable thin film system being possibly subjected to an annealing process to enhance the durability and hardness of said optically variable thin film system.
According to another aspect of the present invention there is further provided a method of authenticating a substrate made of non-fibrous material with an optically variable thin film system constituted of a plurality of optical thin film layers comprising the steps of: applying at least one optical thin film layer of light absorbing material on a surface of said substrate; applying at least one optical thin film layer of non-light absorbing material on top of said layer of light absorbing material whereby said layer of light absorbing material acts as an adhesive between said surface for said nonlight absorbing material and providing a base color, said light and non-light absorbing optical thin film layers forming a filter, said filter changing colors with changing angles of incident light; and subjecting said optically variable thin film system to an annealing process to enhance the durability and hardness of said optically variable thin film system.
Preferably, the outermost layer of the thin film system is a protective layer made of non-light absorbing material and is applied before subjecting the optically variable thin film system to the annealing process, to enhance the durability and hardness of the optically variable thin film system to accommodate stamping of the substrate without affecting the optical properties and lifetime of the optically variable thin film system. This allows the authentication of the substrate to be readily incorporated into a minting process.
The present invention provides advantages in that since the optically variable thin film system can be placed on coin currency or other non-fibrous substrates, the monetary value of coin currency can be increased significantly due to the fact that the likelihood of counterfeit coins having such a thin film system thereon is small.
Brief Description of Drawings
An embodiment of the present invention will be described more fully with reference to the accompanying drawings in which:
Figure 1 is a top plan view of a coin having an optically variable thin film system thereon;
Figure 2 is the cross sectional view of the coin illustrated in Figure 1;
Figure 3 is an enlarged view of the layer system depicted in Figure 2 showing the individual layers of which it is comprised;
Figure 4 is the spectral reflectance curve of one particular thin film system of the type illustrated in Figures 1 and 3.
Figure 5 is a diagram showing the variation of the CIE coordinates with angle of incidence corresponding to the optically variable layer system whose reflectance is shown in Figure 4.
Detailed Description
Although the embodiment of the invention in the following text refers to coins only, within the spirit and scope of the invention it can be applied to medals, tokens, and precious metals and other non-fibrous articles.
Figure 1 represents the plan view of a coin 10 to be protected by an optically variable thin film system 12 in accordance with the invention. A cross sectional view a-a of the coin is shown in Figure 2A. The optically variable thin film system 12 having a color change with angle of viewing is applied to the whole or part of the surface 14 of the substrate 10. Figure 2B represents a different embodiment in which an additional optically variable thin film system 18 is applied to the surface 16 of substrate 10. The thin film system 18 may be the same as or different from the system 12. The optically variable thin film systems 12 and 18 enable individuals to distinguish at glance an authentic coin from a counterfeit one by tilting the coin and observing the color change.
In the following description any statement made about system 12 will be c siyrscftoemm 118 δ
A greatly enlarged cross-sectional view of the optically variable thin film system 12 is shown in Figure 3. The body of the coin 10 acts as a substrate for the thin film system 12. The thin film system 12 consists of layer groups 20, 22 and 24 deposited on top of each other. The purpose of layer group 20 is to enhance the adhesion between the surface 14 of the coin 10 and the subsequent layer group 22. This is very important in view of the wear-and-tear that coins are normally exposed to. An additional function of group 20 may be to provide a base color for the thin film system 12. Layer group 22 consisting of at least one layer, the optional protective layer group 24 and the layer group 20 provide together the required color and color change characteristics.
The perceived color of the light reflected by the coin depends on the light source, the thin film system 12 and the color of the surface 14 which absorbs some of the light transmitted through the thin film system 12. In order to eliminate the influence of the color of the surface 14, the first layer in layer group 20 may be an opaque metal layer that provides the required base color. This layer must also provide a good adhesion between surface 14 and the remaining layers of the thin film system 12. Suitable metals for this purpose are Co, Cr, Ni, Rh and the alloys Inconel and Ni/Cr, etc. If the coin surface 14 is to provide the base color, a transparent adhesive layer must be used. Suitable materials are Al2O3, SiO2, ZrO2, etc.
Group 22 can consist of dielectric materials only, such as Al2O3, CeO2, Hf02, MgF2, Nb2O5, SiO, SiO2, Ta^, TiO2, Y2O3, ZnS, ZrO2. Alternatively, layer group 22 may contain dielectric layers made of above materials and as well as metals layers made of Ag, Al, Au, Co, Cr, Cu, Ge, Hf, Inconel, Mo, Nb, Ni, NiCr, Pt, Rh, Si, Ta, Te, Ti, W, Yr,
Zr. The second approach usually requires fewer layers to achieve satisfactory color change characteristics but may result in a somewhat less chemically stable system.
Layer group 24 consists of materials that are mechanically and chemically very stable and provide additional protection for the thin film system. This is especially important if the layers are deposited onto blanks for use in a minting process.
The number of optical thin film layers in group 22 depends on the desired color properties. Generally, the more layers there are, the more saturated the colors that can be achieved. The materials and thicknesses of the individual layers are selected to optimize the performance of the thin film system 12 not only with respect to the optical characteristics but also to minimize the stress. This is required to achieve a mechanically stable system. The underlying principles for the design of optically variable thin film
systems has been described in detail in the paper by Dobrowolski et al. in Applied Optics Vol. 28, pp. 2702-2717, 1989. Therefore this topic will not be further discussed herein.
Prior to the deposition of the thin film system 12, the surface 14 must be thoroughly cleaned. This is done with one or more the following: solvents, ultrasound, vacuum, heating, or plasma cleaning techniques. Once the surface 14 is clean, the thin film system is formed one layer at a time. The methods for the deposition of the layers ma be selected from the following: thermal evaporation by induction or resistance heating, electron-beam or laser evaporation, ion-assisted and ion plating evaporation, AC and DC magnetron sputtering, chemical vapor deposition from a liquid or gaseous phase, etc. Since these techniques are well known in the art and are discussed in the books by Vossen and Kern , entiled "Thin Film Processes", Vol. I and π, published in 1978 and 1991 by Academic Press of Boston.
After its deposition the thin film system 12 may be subjected to an annealing process to enhance the durability and hardness. The annealing method may involve one or more of the following processes: heating, compression, plasma treatments or ion assisted techniques.
The above procedures results in coins with optically variable properties that remain intact for the duration of their lifetime which is typically between 20 and 40 years. The annealing process also allows the substrate 10 with the optically variable thin film system 12 on it to be struck or stamped without affecting the optical properties of the thin film system.
A coin having an optically variable thin film system 12 applied to it which undergoes a gold to green color change as the angle of incident light changes from normal to non-normal angles was made. In this example, the layer group 20 consists of a single opaque Inconel film- The layer group 22 consists of four dielectric layers made of SiO2 and ZrO2. Because the last layer in this group is made of ZrO2 (a material that is very hard), the optional protective layer group 24 is not necessary. The specific layer structure is shown in Table 1 below, where the layers numbers correspond to the order of the deposition of the layers on the substrate 10.
Figure 4 shows the spectral reflectance curve 30 for normal incidence of light of the optically variable thin film system 12 made in accordance with the parameters set out in Table 1. This results in a gold color. The standard method of representing colors is with the aid of the Commission Internationale de l'Eclairage (CIE) chromaticity diagrams
which are explained in detail, for example, in the book by G. Wyszecki and W.S. Styles entitled "Color Science", published by John Wiley & Sons, New York 1967. The color variation 40 with angle of incidence of the coin 10 is shown in the CIE chromaticity diagram of Figure 5. The points corresponding to angles of incidence of 0, 45 and 75 degrees are indicated in the diagram and the corresponding JC and y CIE coordinates and the luminous reflectances L are listed in Table 2. It is seen that the color changes from gold to green to white. The reflectance curves 32 and 34 for unpolarized light incident at 45 and 75 degrees respectively, are also shown in Figure 4.
The present invention is not restricted to the thin film layer system presented in
Table 1. It will be obvious to those skilled in the art that many different multilayers can be employed to meet the objectives of this invention.
The present invention allows coins, medals, tokens and other articles made of non- fibrous materials to be authenticated against counterfeiting. In the case of coins, the face values can be increased with less worry about counterfeiting. In addition, since the optically variable thin film system 12 can be applied to the coin 10 either before or after it is stamped, the coin authentication process can be readily incorporated into the minting process. The present invention further provides a protection against mechanical and environmental damage and extends the life of the articles protected.
TABLE 1
TABLE 2
Claims
1. An authenticated substrate made of a non-fibrous material having at least one generally planar surface and an optically variable thin film system deposited directly onto said substrate, said optically variable thin film system changing colors with changing angles of incident light and consisting of at least two thin film layers selected from dielectric, semiconducting and metallic materials, one of said at least two layers acting as an adhesive to bond securely said optically variable thin film system to said substrate, said optically variable thin film system being subjected to an annealing process to enhance the durability and hardness of said optically variable thin film system.
2. An authenticated substrate as defined in claim 1 wherein said substrate is in the forms of coins, medals and tokens and wherein said optically variable thin film system withstands striking and stamping without affecting the optical properties thereof.
3. An authenticated substrate as defined in claim 1 wherein said optically variable thin film system covers at least part of said surface of said articles.
4. An authenticated substrate as defined in claim 1 wherein said optically variable thin film system further includes a protective coating having at least one layer made of a transparent material.
- 5. A method of authenticating a substrate made of a non-fibrous material with an optically variable thin film system constituted by a plurality of optical thin film layers comprising the steps of: applying at least one optical thin film layer of light absorbing material on a surface of said substrate; applying at least one optical thin film layer of non-light absorbing material on top of said layer of light absorbing material whereby said layer of light absorbing material acts as an adhesive between said surface and said nonlight absorbing material, said light and non- light absorbing optical thin film layers forming a filter, said filter changing colors with changing angles of incident light; and subjecting said optically variable thin film system to an annealing process to enhance the durability and hardness of said optically variable thin film system; and, ="
6. The method of claim 5 wherein a protective coating of non-light absorbing material is applied over said other of said at least two layers, said optically variable thin film system being annealed to enhance the durability and hardness of said thin film system after said protective coating is applied.
7. The method of claim 6 wherein said substrate is in the form of a metal blank and further including the step of stamping said surface to imprint a pattern thereon after said annealing step has been performed.
8. The method of claim 7 wherein said substrate is one of a coin, medal, token or precious metal.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US87707592A | 1992-05-01 | 1992-05-01 | |
| US07/877,075 | 1992-05-01 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO1993022746A1 true WO1993022746A1 (en) | 1993-11-11 |
Family
ID=25369192
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/CA1993/000180 WO1993022746A1 (en) | 1992-05-01 | 1993-05-03 | Optically variable coins, medals, tokens and other non-fibrous articles and method for making same |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO1993022746A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996025066A1 (en) * | 1995-02-15 | 1996-08-22 | Etablissements Bourgogne Et Grasset | Gambling chip and method for marking same |
| US7063012B2 (en) | 2002-07-22 | 2006-06-20 | Gaming Partners International | Method for marking by pad-printing and sublimation, and sublimable pad-printing inks |
| US7100501B2 (en) | 2001-06-06 | 2006-09-05 | Gaming Partners International | Chip holding arrangement, pad printing system incorporating the arrangement, and method of pad printing a chip using the arrangement |
| CN102511977A (en) * | 2011-12-20 | 2012-06-27 | 上海造币有限公司 | Noble metal coin with transparent anti-counterfeit window, and manufacturing technology thereof |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2126670A5 (en) * | 1971-02-12 | 1972-10-06 | Nocerito Roberto | |
| GB2083842A (en) * | 1980-09-09 | 1982-03-31 | Westinghouse Electric Corp | Transparent abrasive resistant sputtered films on metal substrates |
| US4371071A (en) * | 1981-04-24 | 1983-02-01 | Abedor Allan J | Token sensing photodetector actuated electronic control and timing device and method of use |
| EP0083808A1 (en) * | 1982-01-08 | 1983-07-20 | Joh. Enschedé en Zonen Grafische Inrichting B.V. | Process for manufacturing a plastic token, and token manufactured by said process |
| EP0160409A1 (en) * | 1984-04-07 | 1985-11-06 | Mixalloy Limited | Improvements in and relating to the production of flat products in strip, sheet or like form |
| EP0197185A2 (en) * | 1985-04-11 | 1986-10-15 | Kernforschungszentrum Karlsruhe Gmbh | Multilayered and highly wear-resistant protective coating of hard material for metallic surfaces or substrates subjected to a high load |
| US4626445A (en) * | 1984-11-09 | 1986-12-02 | Canadian Patents And Development Limited | Method of manufacturing an optical interference authenticating device |
| EP0353060A2 (en) * | 1988-07-28 | 1990-01-31 | Nippon Steel Corporation | Multi ceramic layer-coated metal plate and process for manufacturing same |
| WO1991014998A1 (en) * | 1990-03-29 | 1991-10-03 | Jani Supplies Enterprises, Inc. | Tokens having minted identification codes |
-
1993
- 1993-05-03 WO PCT/CA1993/000180 patent/WO1993022746A1/en active Application Filing
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2126670A5 (en) * | 1971-02-12 | 1972-10-06 | Nocerito Roberto | |
| GB2083842A (en) * | 1980-09-09 | 1982-03-31 | Westinghouse Electric Corp | Transparent abrasive resistant sputtered films on metal substrates |
| US4371071A (en) * | 1981-04-24 | 1983-02-01 | Abedor Allan J | Token sensing photodetector actuated electronic control and timing device and method of use |
| EP0083808A1 (en) * | 1982-01-08 | 1983-07-20 | Joh. Enschedé en Zonen Grafische Inrichting B.V. | Process for manufacturing a plastic token, and token manufactured by said process |
| EP0160409A1 (en) * | 1984-04-07 | 1985-11-06 | Mixalloy Limited | Improvements in and relating to the production of flat products in strip, sheet or like form |
| US4626445A (en) * | 1984-11-09 | 1986-12-02 | Canadian Patents And Development Limited | Method of manufacturing an optical interference authenticating device |
| EP0197185A2 (en) * | 1985-04-11 | 1986-10-15 | Kernforschungszentrum Karlsruhe Gmbh | Multilayered and highly wear-resistant protective coating of hard material for metallic surfaces or substrates subjected to a high load |
| EP0353060A2 (en) * | 1988-07-28 | 1990-01-31 | Nippon Steel Corporation | Multi ceramic layer-coated metal plate and process for manufacturing same |
| WO1991014998A1 (en) * | 1990-03-29 | 1991-10-03 | Jani Supplies Enterprises, Inc. | Tokens having minted identification codes |
Non-Patent Citations (3)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN vol. 13, no. 580 (P-980)21 December 1989 * |
| PATENT ABSTRACTS OF JAPAN vol. 16, no. 565 (P-1457)7 December 1992 * |
| PATENT ABSTRACTS OF JAPAN vol. 17, no. 54 (P-1480)3 February 1993 * |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996025066A1 (en) * | 1995-02-15 | 1996-08-22 | Etablissements Bourgogne Et Grasset | Gambling chip and method for marking same |
| US5794532A (en) * | 1995-02-15 | 1998-08-18 | Etablissements Bourgogne Et Grasset | Gambling chip and method of marking same |
| AU698267B2 (en) * | 1995-02-15 | 1998-10-29 | Gaming Partners International | Gambling chip and method of marking such a gambling chip |
| US7100501B2 (en) | 2001-06-06 | 2006-09-05 | Gaming Partners International | Chip holding arrangement, pad printing system incorporating the arrangement, and method of pad printing a chip using the arrangement |
| US7063012B2 (en) | 2002-07-22 | 2006-06-20 | Gaming Partners International | Method for marking by pad-printing and sublimation, and sublimable pad-printing inks |
| US7563834B2 (en) | 2002-07-22 | 2009-07-21 | Gaming Partners International | Sublimable pad-printing inks |
| CN102511977A (en) * | 2011-12-20 | 2012-06-27 | 上海造币有限公司 | Noble metal coin with transparent anti-counterfeit window, and manufacturing technology thereof |
| CN102511977B (en) * | 2011-12-20 | 2014-06-04 | 上海造币有限公司 | Noble metal coin with transparent anti-counterfeit window, and manufacturing technology thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20190346596A1 (en) | Optically variable security devices | |
| CN101790464B (en) | Safety element | |
| US8317231B2 (en) | Security element with metallization | |
| CN102089123B (en) | Security element | |
| US7699350B2 (en) | Security element and security document with one such security element | |
| US9016726B2 (en) | Security element having a microstructure | |
| AU2010341173B2 (en) | Gold-coloured thin-layer element having a multilayered structure | |
| RU2309853C2 (en) | Forgery-protected document and protective element for same | |
| CN1597334B (en) | Counterfeiting line and method for manufacturing optical variable device | |
| US9308774B2 (en) | Security element comprising a screened layer | |
| CN100429083C (en) | Optically variable element comprising a partially transparent element | |
| RU2313456C2 (en) | Protective element with color kipp effect and magnetic properties, object with such a protective element, and method for manufacturing such protective element and such object | |
| EP0165021A2 (en) | A form depicting optical interference authenticatting device | |
| KR20020071955A (en) | Optically variable security devices | |
| EP3445592B1 (en) | Security devices and methods of manufacture thereof | |
| WO1993022746A1 (en) | Optically variable coins, medals, tokens and other non-fibrous articles and method for making same | |
| CN111716936B (en) | Optical anti-counterfeiting element and optical anti-counterfeiting product | |
| US11768321B2 (en) | Optically variable security devices | |
| US20230305202A1 (en) | Optically variable security devices | |
| US20230347680A1 (en) | Metallic sheet with security window and methods of manufacture | |
| WO2022144258A1 (en) | Security element for documents, particularly banknotes, and method for its production | |
| KR20040060267A (en) | A Security Seat And Product Method To Be Anti-forgery Effect, A Security paper Prepared Security Thread | |
| AU2003222834A1 (en) | Security element comprising metallic layers |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AK | Designated states |
Kind code of ref document: A1 Designated state(s): CA |
|
| AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LU MC NL PT SE |
|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
| 122 | Ep: pct application non-entry in european phase | ||
| NENP | Non-entry into the national phase |
Ref country code: CA |