阅读说明：本技术 基于旋转表面的光学安全装置 (Optical security device based on a rotating surface ) 是由 V·P·拉克沙 科尼利斯·简·德尔斯特 于 2019-08-12 设计创作，主要内容包括：公开了基于旋转表面的光学安全装置。印刷在基底上的光学制品可以包括有机粘合剂；以及设置在有机粘合剂中的多个反射磁性薄片,其中多个反射磁性薄片按照旋转表面的至少一部分基本上对齐,并且其中多个反射磁性薄片被对齐以在基底围绕第一轴旋转时引起光学制品的第一反射效果,并且在基底围绕第二轴旋转时引起光学制品的第二反射效果,其中第一反射效果不同于第二反射效果。(Optical security devices based on rotating surfaces are disclosed. The optical article printed on the substrate may include an organic binder; and a plurality of reflective magnetic flakes disposed in the organic binder, wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of the rotating surface, and wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article when the substrate is rotated about the first axis and a second reflective effect of the optical article when the substrate is rotated about the second axis, wherein the first reflective effect is different from the second reflective effect.)

1. An optical article printed on a substrate, comprising:

an organic binder; and

a plurality of reflective magnetic flakes disposed in the organic binder,

wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of a surface of rotation, and

wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article as the substrate is rotated about a first axis and to cause a second reflective effect of the optical article as the substrate is rotated about a second axis,

wherein the first reflective effect is different from the second reflective effect.

2. The optical article of claim 1, wherein the rotating surface is substantially funnel-shaped.

3. The optical article of claim 1, wherein the surface of revolution is defined based on a parabola or a hyperbola.

4. The optical article of claim 1, wherein the surface of revolution is substantially shaped as a hyperbolic paraboloid.

5. The optical article of claim 1, wherein the first axis is a horizontal axis and the second axis is a vertical axis.

6. The optical article of claim 1, wherein the first axis is orthogonal to the second axis.

7. The optical article of claim 1, wherein the surface of revolution is defined based on natural logarithms.

8. A method for forming an optical article on a substrate, comprising:

providing an organic binder comprising a plurality of reflective magnetic flakes on the substrate;

applying a magnetic field to the organic binder using one or more magnets, wherein the magnetic field substantially aligns the plurality of reflective magnetic flakes according to at least a portion of a rotating surface,

wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article as the substrate is rotated about a first axis and to cause a second reflective effect of the optical article as the substrate is rotated about a second axis,

wherein the first reflective effect is different from the second reflective effect; and

allowing the organic binder to set or harden.

9. The method of claim 8, wherein the rotating surface is substantially funnel-shaped.

10. The method of claim 8, wherein the one or more magnets comprise two magnets disposed parallel to each other, and wherein corners of the two magnets are cut or rounded.

11. The method of claim 8, wherein the surface of revolution is substantially shaped as a hyperbolic paraboloid.

12. The method of claim 8, wherein the one or more magnets comprise two generally triangular magnets provided in a coplanar manner.

13. The method of claim 12, wherein the first sides of the two generally triangular magnets are disposed parallel to and away from the organic adhesive, and wherein the second sides of the two generally triangular magnets are disposed perpendicular to the organic adhesive and in contact with each other.

14. The method of claim 8, wherein the one or more magnets comprise a magnet having two or more triangular notches.

15. A document, comprising:

an optical article comprising a plurality of reflective magnetic flakes,

wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of a surface of rotation, and

wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article as the optical article rotates about a first axis and to cause a second reflective effect of the optical article as the optical article rotates about a second axis,

wherein the first reflective effect is different from the second reflective effect.

16. A document according to claim 15, wherein the first reflective effect is a widening of a first portion of a reflection from the optical article and a narrowing of a second portion of the reflection from the optical article.

17. A document according to claim 15, wherein the second reflective effect is a first lateral movement of a first portion of a reflection from the optical article that is greater than a second lateral movement of a second portion of the reflection from the optical article.

18. A document according to claim 15, wherein the first reflective effect is a first movement of left and right portions of a reflection from the optical article that is greater than a second movement of a central portion of the reflection from the optical article.

19. A document according to claim 15, wherein the second reflective effect is a lightening of a first half of a reflection from the optical article and a darkening of a second half of the reflection from the optical article.

20. A document according to claim 15, wherein the first axis is a horizontal axis and the second axis is a vertical axis.

Technical Field

This application relates to, but is not limited to, optical security devices.

Background

Some documents (documents), such as monetary instruments, certificates, and/or the like, may be secured against counterfeiting using certain optical articles. One example of such an optical article is an ink having variable optical properties (e.g., color, reflectivity) based on viewing angle.

Disclosure of Invention

In some possible embodiments, the optical article printed on the substrate may comprise: an organic binder; and a plurality of (a plurality of) reflective magnetic flakes (platlets) disposed in the organic binder, wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of the surface of rotation, and wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article when the substrate is rotated about the first axis and a second reflective effect of the optical article when the substrate is rotated about the second axis, wherein the first reflective effect is different from the second reflective effect.

In some possible embodiments, a method for forming an optical article on a substrate may include: providing an organic binder on a substrate, the organic binder comprising a plurality of reflective magnetic flakes; applying a magnetic field to the organic binder using one or more magnets, wherein the magnetic field substantially aligns the plurality of reflective magnetic flakes according to at least a portion of the rotating surface, wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article when the substrate is rotated about the first axis and a second reflective effect of the optical article when the substrate is rotated about the second axis, wherein the first reflective effect is different from the second reflective effect; and setting or hardening the organic binder.

In some possible embodiments, the document may include an optical article comprising a plurality of reflective magnetic flakes, wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of the surface of rotation, and wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article when the optical article is rotated about a first axis and to cause a second reflective effect of the optical article when the optical article is rotated about a second axis, wherein the first reflective effect is different from the second reflective effect.

Aspects of the disclosure may be implemented in one or more of the following embodiments:

1) an optical article printed on a substrate, comprising:

an organic binder; and

a plurality of reflective magnetic flakes disposed in the organic binder,

wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of a surface of rotation, and

wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article as the substrate is rotated about a first axis and to cause a second reflective effect of the optical article as the substrate is rotated about a second axis,

wherein the first reflective effect is different from the second reflective effect.

2) The optical article of claim 1), wherein the rotating surface is substantially funnel-shaped.

3) The optical article of claim 1), wherein the surface of revolution is defined based on a parabola or a hyperbola.

4) The optical article of claim 1), wherein the surface of revolution is substantially shaped as a hyperbolic paraboloid.

5) The optical article of 1), wherein the first axis is a horizontal axis and the second axis is a vertical axis.

6) The optical article of claim 1), wherein the first axis is orthogonal to the second axis.

7) The optical article of claim 1), wherein the surface of revolution is defined based on natural logarithms.

8) A method for forming an optical article on a substrate, comprising:

providing an organic binder comprising a plurality of reflective magnetic flakes on the substrate;

applying a magnetic field to the organic binder using one or more magnets, wherein the magnetic field substantially aligns the plurality of reflective magnetic flakes according to at least a portion of a rotating surface,

wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article as the substrate is rotated about a first axis and to cause a second reflective effect of the optical article as the substrate is rotated about a second axis,

wherein the first reflective effect is different from the second reflective effect; and allowing the organic binder to set or harden.

9) The method of 8), wherein the rotating surface is substantially funnel-shaped.

10) The method of 8), wherein the one or more magnets comprise two magnets disposed parallel to each other, and wherein corners of the two magnets are cut or rounded.

11) The method of 8), wherein the surface of revolution is substantially shaped as a hyperbolic paraboloid.

12) The method of 8), wherein the one or more magnets comprise two generally triangular magnets provided in a coplanar manner.

13) The method of 12), wherein first sides of the two substantially triangular magnets are disposed parallel to and away from the organic adhesive, and wherein second sides of the two substantially triangular magnets are disposed perpendicular to the organic adhesive and in contact with each other.

14) The method of 8), wherein the one or more magnets comprise a magnet having two or more triangular notches.

15) A document, comprising:

an optical article comprising a plurality of reflective magnetic flakes,

wherein the plurality of reflective magnetic flakes are substantially aligned according to at least a portion of a surface of rotation, and

wherein the plurality of reflective magnetic flakes are aligned to cause a first reflective effect of the optical article as the optical article rotates about a first axis and to cause a second reflective effect of the optical article as the optical article rotates about a second axis,

wherein the first reflective effect is different from the second reflective effect.

16) A document according to 15), wherein the first reflective effect is a widening of a first portion of a reflection from the optical article and a narrowing of a second portion of the reflection from the optical article.

17) A document according to 15), wherein the second reflective effect is a first lateral movement of a first portion of a reflection from the optical article that is greater than a second lateral movement of a second portion of the reflection from the optical article.

18) A document according to 15), wherein the first reflective effect is a first movement of left and right portions of a reflection from the optical article that is greater than a second movement of a central portion of the reflection from the optical article.

19) A document according to 15), wherein the second reflective effect is a brightening of a first half of a reflection from the optical article and a darkening of a second half of the reflection from the optical article.

20) The file of 15), wherein the first axis is a horizontal axis and the second axis is a vertical axis.

Drawings

Fig. 1A-1E are schematic illustrations of optical articles formed based on funnel-shaped rotating surfaces.

Fig. 2A and 2B are schematic views of another optical article formed based on a funnel-shaped rotating surface.

Fig. 3A-3D are schematic illustrations of optical articles formed based on saddle-shaped rotating surfaces.

FIG. 4 is a flow chart of an example process for forming an optical article based on a rotating surface.

Detailed Description

The following detailed description of example embodiments refers to the accompanying drawings. The same reference numbers in different drawings may identify the same or similar elements.

The optical article may produce a reflective effect based on the angle or viewing angle of the light. Some optical articles may use reflective magnetic flakes to create this reflective effect. For example, the magnetic flakes may be dispersed in an organic binder and coated on a substrate, such as a flexible substrate (e.g., a document, currency, certificate, transaction card, etc.). The magnetic flakes may be aligned according to (e.g., using) a magnetic field, which may cause the magnetic flakes to exhibit the reflective properties of the shaped three-dimensional mirror. This may be referred to as a fresnel-like reflection effect. The organic adhesive may be cured or hardened (e.g., using curing, ultraviolet light, heat, epoxy, etc.). Notably, the optical article can be thin (e.g., may not be significantly thicker than the substrate) and flexible, which makes the optical article useful for currency and other such applications.

Some embodiments described herein provide optical articles based on a rotating surface. A surface of revolution is a three-dimensional surface generated by rotating a two-dimensional curve around an axis. The surface of rotation may have azimuthal symmetry. Some embodiments described herein may use a magnetic field generated based on a rotating surface to produce a rotating surface based reflection effect. For example, some embodiments described herein may be based on a funnel-shaped rotating surface, and may provide a reflective effect similar to a funnel in certain orientations. Other embodiments described herein may be based on saddle-shaped rotating surfaces and may provide a reflective effect similar to a saddle in certain orientations.

The optical article may have magnetic flakes aligned to cause a first reflective effect of the optical article when the substrate (or optical article) is rotated about a first axis and a second, different reflective effect when the substrate or optical article is rotated about a second axis. The reflection effect and accordingly the magnet configuration for aligning the magnetic flakes is described in more detail below. By providing reflective effects that are different when the optical article is rotated about different axes, the complexity of the optical article is increased as compared to optical articles that use a single axis of rotation. Thus, the security of a document using the present optical article is improved compared to a document using an optical article using a single rotation axis.

Fig. 1A-1E are schematic illustrations of an example 100 of an optical article 102 formed based on a funnel-shaped rotating surface. An enlarged view of the optical article 102 in a first view (e.g., a frontal view without rotating the substrate 104 about an axis) is shown at the top of fig. 1A. Here, the substrate 104 is a document such as a banknote. In some embodiments, the substrate 104 may not include a document. For example, the optical article 102 can be formed on a substrate that is attached to the document (e.g., before or after the optical article 102 is formed).

As shown, the optical article 102 exhibits a funnel-shaped reflection, which may be based on alignment of magnetic flakes of the optical article 102 using a magnetic field based on a funnel-shaped rotating surface. This is described in more detail below in conjunction with fig. 1B and 1C.

As indicated by reference numeral 106, as the substrate 104 (or optical article 102) is rotated about a first axis (e.g., a horizontal axis), the rotation may result in a first reflective effect 108. Here, the first reflection effect 108 is a widening (in the horizontal direction) of the top of the funnel-shaped reflection and a narrowing (in the horizontal direction) of the bottom of the funnel-shaped reflection. This may be based on the alignment of the magnetic flakes with the funnel-shaped rotating surface, as described in more detail below. In some embodiments, the first reflective effect may be a widening of a first portion (e.g., the top) of the reflection and a narrowing of a second portion (e.g., the bottom) of the reflection.

As indicated by reference numeral 110, when the substrate 104 (or optical article 102) is rotated about a second axis (e.g., a vertical axis and/or an axis orthogonal to the first axis), the rotation may result in a second reflective effect 112 that is different from the first reflective effect 108. Here, the second reflection effect 112 is that the top of the funnel-shaped reflection moves to the left, while the bottom point of the funnel-shaped reflection remains substantially stationary. In other words, the second reflective effect may be a first lateral movement of the first portion of the reflection (e.g., a left or right movement of the top of the funnel-shaped reflection) that is greater than a second lateral movement of the second portion of the reflection (e.g., the bottom point remains substantially stationary).

FIG. 1B shows an example of a rotating surface for producing the optical article 102 shown in FIG. 1A and a curve for producing the rotating surface. This curve is shown by reference numeral 114. As shown, the curve may be defined based on natural logarithms. In some embodiments, the curve may be defined based on another mathematical relationship, such as logarithmic, or the like. The surface of rotation may be created by rotating the curve about the Y-axis, as indicated by reference numeral 116. For clarity, a checkered depiction of the rotating surface is shown by reference numeral 118.

The rotating surface shown in FIG. 1B is shown for illustrative purposes only. The precise magnetic field used to align the magnetic flakes may differ from that shown in fig. 1B based on variations in magnet manufacturing, challenges in field shaping, or other reasons. For example, the deviation of the field may range from about 0.03125 "to 2" or more, based on the designer's choice and the choice of magnet size. It should be understood that the rotating surfaces described herein are provided for exemplary and illustrative purposes only.

Fig. 1C shows an example of a configuration of the magnet 120, the magnet 120 may provide a magnetic field approximating the rotating surface shown by reference numerals 116 and 118 of fig. 1B. The plane of the optical article 102 is shown by reference numeral 122. It can be seen that the magnetic field lines generated by such magnets may have different radii in the plane 122. Thus, the optical article 102 providing the funnel-shaped reflective effect shown in FIG. 1A may be formed based on the rotating surfaces 116, 118 shown in FIG. 1B using the magnet 120 shown in FIG. 1C.

An example of the optical article 102 is shown in fig. 1D by reference numeral 124. For example, the example shown in fig. 1D may represent a cross-section of the optical article 102 in the center of the optical article 102. As shown, the optical article 102 may include an organic binder 126 with reflective magnetic flakes 128 suspended in the organic binder 126. As further shown, the optical article 102 is disposed on a substrate 130. The reflective magnetic flakes 128 can be aligned with the magnetic field lines 132.

Fig. 1E shows an oblique view 134 of the flux lines 132 of fig. 1D. The central axis of the magnetic field represented by field line 132 is shown by the "x" symbol identified by reference numeral 136. It can be seen that the radius of the flux lines 132 varies along the central axis. As shown, the central axis of the magnetic field is located below substrate 130 at a narrower cross-section of the magnetic field and progresses toward substrate 130 and through substrate 130 as the magnetic field widens. Other embodiments of the orientation of the central axis are also possible. For example, the central axis may be disposed entirely above the substrate, entirely below the substrate, disposed parallel to the substrate, travel through the substrate, and the like.

1A-1E are provided as examples. Other examples are possible and may differ from the examples described with respect to fig. 1A-1E.

Fig. 2A and 2B are schematic diagrams of another example of an optical article 200 formed based on a funnel-shaped rotating surface. The rotating surface for example 200 may be substantially similar to the rotating surface for example 100 of fig. 1A-1D and, thus, is not shown.

An enlarged view of the optical article 202 in a first view (e.g., a frontal view without rotating the substrate 204 about an axis) is shown at the top of fig. 2A. As shown, the optical article 202 exhibits a funnel-shaped reflection that is narrower at the top and wider at the bottom compared to the funnel-shaped reflection of the optical article 102. This may be due to differences in the shape and/or orientation of the magnets used to form the respective magnetic fields, as described below in connection with fig. 2B.

As indicated by reference numeral 206, as the substrate 204 (or optical article 202) is rotated about a first axis (e.g., a horizontal axis), the rotation may result in a first reflective effect 208. Here, the first reflection effect 208 is a widening (in the horizontal direction) of the top of the funnel-shaped reflection and a narrowing (in the horizontal direction) of the bottom of the funnel-shaped reflection. As indicated by reference numeral 210, when the substrate 204 (or optical article 202) is rotated about a second axis (e.g., a vertical axis and/or an axis orthogonal to the first axis), the rotation may result in a second reflective effect 212 that is different from the first reflective effect 208. Here, the second reflection effect 212 is a leftward movement of the top of the funnel-shaped reflection.

Fig. 2B shows an example of a configuration of a set of magnets 214 that may be used to create the optical article 202, the set of magnets 214 may provide a magnetic field that approximates a rotating surface. The plane of the optical article 202 is shown by reference numeral 216. As shown, the arrangement of the set of magnets 214 may provide a magnetic field having an elongated shape as compared to the magnetic field shown in fig. 1C. In some aspects, more than two magnets 214 may be used. For example, any number of magnets 214 may be used to generate the magnetic field shown. Thus, the set of magnets 214 shown in FIG. 2B may be used to form the optical article 202 that provides the funnel-shaped reflective effect shown in FIG. 2A.

As indicated above, fig. 2A and 2B are provided as examples only. Other examples are possible and may differ from the examples described with respect to fig. 2A and 2B.

Fig. 3A-3D are schematic diagrams of an example 300 of an optical article formed based on a saddle-shaped rotating surface. An enlarged view of the optical article 302 in a first view (e.g., a frontal view without rotating the substrate 304 about an axis) is shown at the top of fig. 3A. As shown, optical article 302 exhibits a saddle-shaped reflective effect (for the example of a saddle shape, see the saddle-shaped rotating surface of fig. 3C, which is described in more detail below).

As indicated by reference numeral 306, when the optical article 302 is rotated in a first direction about a first axis (e.g., a horizontal axis), the rotation can cause a first reflective effect, wherein the reflection moves downward at the edges, while the center remains substantially stationary. For example, the left and right portions of the reflection may be curved downward. As indicated by reference numeral 308, when the optical article 302 is rotated about the first axis in the second direction, the reflection moves upward at the edges, while the center remains substantially stationary. For example, the left and right portions of the reflection may be curved upward. It can be seen that the areas of the optical article 302 not occupied by the reflected light band (e.g., the triangular portions of the top center and the bottom center of the optical article 302) remain dark as the optical article 302 rotates about the first axis.

As shown by reference numeral 310 in fig. 3B, when the optical article 302 is rotated in a first direction about a second axis (e.g., a vertical axis and/or an axis orthogonal to the first axis), the rotation may result in a second reflective effect. Here, the second reflective effect is that the left half (e.g., first half) of the optical article 302 becomes brighter, while the right half (e.g., second half) of the optical article 302 becomes darker. Similarly, as indicated by reference numeral 312, the second reflective effect is a lightening of the right half of the optical article 302 when the optical article 302 is rotated about the second axis in the second direction.

Fig. 3C shows an example of a curve 314 that may be used to generate saddle-shaped rotating surfaces 316, 318. In some implementations, the curve 314 may be a parabola (e.g., defined by the equation x b y 2+ C (b and C not shown in fig. 3C)) or may be a hyperbola, and the rotating surfaces 316, 318 may be hyperbolic parabolas or portions of hyperbolic parabolas.

Fig. 3D illustrates an example of a magnet configuration that may be used to generate a magnetic field based on the saddle-shaped rotating surfaces 316, 318 to form the optical article 302. As indicated by reference numeral 320, the first configuration of magnets may include generally triangular magnets provided in a coplanar manner in a plane orthogonal to a plane 322 of the optical article 302. For example, the first sides 324 of the two generally triangular magnets may be disposed parallel to the plane 322 and away from the plane 322, and the second sides 326 of the two generally triangular magnets may be disposed in a plane perpendicular to the organic adhesive and in contact with each other (or spaced apart from each other). As indicated by reference numeral 328, the second configuration may include magnets having triangular notches 330. In some embodiments, the second configuration may use two triangular magnets meeting at a center point and having a rectangular portion 332 away from the center point 334.

3A-3D are provided as examples only. Other examples are possible and may differ from the examples described with respect to fig. 3A-3D.

Fig. 4 is a flow diagram of an example process 400 for forming an optical article according to various embodiments described herein. One or more of the operations described in fig. 4 may be performed by a system, such as a system capable of providing an organic binder including reflective magnetic flakes, applying a magnetic field to the organic binder, and curing or hardening the organic binder.

As shown in fig. 4, the process 400 may include providing an organic adhesive on a substrate, the organic adhesive including a plurality of reflective magnetic flakes (block 410). For example, an organic adhesive may be disposed on the substrate. The organic binder may be an ink or other substance that can be set or hardened by a chemical reaction and is at least partially transparent. In some embodiments, the organic binder may be a highly reactive UV ink for sheet-and web offset presses that is cured using UV lamp technology, such as UV curable inks (e.g., the Flint group XCURA EVO ink, the Flint group ultrasking 6100FAST CURE, etc.). For example, a UV curable ink may include four components: monomers, oligomers, pigments and photoinitiators. The monomer may provide a building block for the ink and may contribute to certain properties, such as softness or hardness of the ink when cured, and flexibility or elongation characteristics of the ink for different types of applications. The oligomers in the ink formulation include a reactive resin and a uniquely formulated binder component for printing on a variety of different substrates. The pigment provides color. When the photoinitiator is exposed to UV light, the oligomers and monomers crosslink or polymerize.

The organic binder may include a plurality of reflective magnetic flakes. The flakes may include substantially flat particles having a size in a range of about 10 μm by 0.5 μm to about 100 μm by 10 μm. The particles may comprise layers of different materials. The one or more materials may be magnetised in the magnetic field of the external magnet or magnets. In some cases, reflective magnetic flakes are one of many security pigment particles. The reflective magnetic flakes may comprise layers made of magnetic soft or hard materials, such as ferromagnetic alloys. The central core may be coated with two or more layers of aluminum as a reflector. The aluminium layer may be coated with a transparent material, such as MgF₂、SiO₂And the like. A translucent chrome layer may be coated on top of the transparent material. This particular material is known as a secure Optically Variable Magnetic Pigment (OVMP). The pigment may be mixed with the UV-curable organic binder described above to form a secure Optically Variable Magnetic Ink (OVMI) for printing security elements on valuable documents.

In some embodiments, the substrate may be a document, or may be attached to a document. In some embodiments, the organic binder and the flakes (and optionally the substrate) may be collectively referred to as an optical article.

As further shown in fig. 4, the process 400 may include applying a magnetic field to the organic binder using one or more magnets, wherein the magnetic field substantially aligns the plurality of reflective magnetic flakes according to at least a portion of the rotating surface (block 420). For example, one or more magnets may be used to apply a magnetic field to the organic binder. In some embodiments, an electric or electromagnetic field may be used to generate a magnetic field to be applied to the organic binder to align the plurality of reflective magnetic flakes. For example, the electric field may substantially have the shape described with respect to examples 100, 200, and/or 300. The magnetic field may substantially align the plurality of reflective magnetic flakes with at least a portion of the rotating surface. For example, the magnetic field may substantially have the shape of at least a portion of a surface of rotation. In some embodiments, the plurality of reflective magnetic flakes can be aligned to cause a first reflective effect of the optical article when the substrate is rotated about the first axis. In addition, the plurality of reflective magnetic flakes can be aligned to cause a second reflective effect of the optical article when the substrate is rotated about the second axis. The first reflective effect may be different from the second reflective effect.

As further shown in fig. 4, the process 400 may include setting or hardening the organic binder (block 430). For example, the organic binder (e.g., ink) may be set or hardened. This can lock the reflective flakes in alignment with a magnetic field (or electric or electromagnetic field). In some embodiments, the organic binder may be cured or hardened using ultraviolet light, using heat, based on curing techniques, and the like.

Process 400 may include additional embodiments, such as any single embodiment or any combination of embodiments described below and/or described in conjunction with one or more other processes described elsewhere herein.

In some embodiments, the surface of rotation is defined based on natural logarithm. In some embodiments, the rotating surface is substantially funnel-shaped. In some embodiments, the surface of rotation is defined based on a parabola or a hyperbola. In some embodiments, the surface of revolution is substantially shaped as a hyperbolic paraboloid. In some embodiments, the first axis is a horizontal axis and the second axis is a vertical axis. In some embodiments, the first axis is orthogonal to the second axis.

In some embodiments, the one or more magnets comprise two magnets disposed parallel to each other, and the corners of the two magnets are cut or rounded. In some embodiments, the one or more magnets comprise two generally triangular magnets provided in a coplanar manner. In some embodiments, the first sides of the two generally triangular magnets are disposed parallel to and away from the organic adhesive, and wherein the second sides of the two generally triangular magnets are disposed perpendicular to the organic adhesive and in contact with each other. In some embodiments, the one or more magnets comprise a magnet having two or more triangular notches.

In some embodiments, the first reflective effect is a broadening of a first portion of the reflection from the optical article and a narrowing of a second portion of the reflection from the optical article. In some embodiments, the second reflective effect is a first lateral motion of a first portion of the reflection from the optical article that is greater than a second lateral motion of a second portion of the reflection from the optical article.

In some embodiments, the first reflective effect is a first movement of the left and right portions of the reflection from the optical article that is greater than a second movement of the central portion of the reflection from the optical article. In some embodiments, the second reflective effect is a brightening of the first half of the reflection from the optical article and a darkening of the second half of the reflection from the optical article.

Although fig. 4 shows example blocks of the process 400, in some implementations, the process 400 may include additional blocks, fewer blocks, different blocks, or a different arrangement of blocks than those depicted in fig. 4. Additionally or alternatively, two or more blocks of process 400 may be performed in parallel.

In this way, different reflection effects are provided when the optical article is rotated about different axes. This may increase the complexity of the optical article. Thus, the security of the document using the optical article is improved.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the embodiments to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the embodiments.

As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and/or a combination of hardware and software.

It will be apparent that the systems and/or methods described herein may be implemented in various forms of hardware, firmware, or combinations of hardware and software. The actual specialized control hardware or software code used to implement the systems and/or methods is not limiting of the embodiments. Thus, the operation and behavior of the systems and/or methods were described herein without reference to the specific software code — it being understood that software and hardware may be designed to implement the systems and/or methods based on the description herein.

Although particular combinations of features are set forth in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of possible embodiments. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed may be directly dependent on only one claim, the disclosure of possible embodiments includes each dependent claim in combination with every other claim in the set of claims.

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. In addition, as used herein, the articles "a" and "an" are intended to include one or more items, and may be used interchangeably with "one or more". Further, as used herein, the term "collection" is intended to include one or more items (e.g., related items, unrelated items, combinations of related items and unrelated items, etc.) and may be used interchangeably with "one or more". Where only one item is intended, the term "one" or similar language is used. Further, as used herein, the terms "having", and the like are intended to be open-ended terms. Further, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.