Security element and article having a security element

Abstract

The present application relates to the field of anti-counterfeiting technology, and discloses an anti-counterfeiting element, comprising: a base material, a characteristic region is arranged on the surface of the base material, and the characteristic region comprises a plurality of curved surface structures; the curved surface structure has a first direction and a second direction which are parallel to the surface of the base material, the curved surface structure is arranged in a curved manner along the first direction, and the curved degree of the curved surface structure along the second direction is less than the curved degree of the curved surface structure along the first direction. By arranging a plurality of curved surface structures in the characteristic region and arranging each curved surface structure in a curved manner along the first direction, the emergent light of the curved surface structure can be emitted in the direction range of a sector under the incidence of light in a predetermined direction, the angle distribution of the emergent light is more uniform, and even the single curved surface structure can obtain the combined effect of a plurality of reflective facets in the prior art, so that a higher resolution dynamic effect can be realized, a more delicate and stable appearance pattern can be realized, and the visual angle range is improved.

Description

Technical Field

[0001] This invention relates to the field of anti-counterfeiting technology, specifically to anti-counterfeiting elements and articles having anti-counterfeiting elements. Background Technology

[0002] To prevent counterfeiting through scanning and photocopying, optical anti-counterfeiting technology has been widely used in various high-security or high-value-added printed materials such as banknotes, certificates, and product packaging, and has achieved very good results.

[0003] Existing technology discloses an anti-counterfeiting element comprising multiple reflective facets. The orientations of the different reflective facets are roughly randomly distributed. Under incident light in a predetermined direction, the orientation of the multiple reflective facets defines the direction of the emitted light, creating a dynamic effect where the appearance changes with the viewing angle. However, this anti-counterfeiting element requires multiple reflective facets to be combined to form a large area to achieve a uniform distribution of the emitted light angle, and the combination of multiple reflective facets also reduces the pattern resolution of the dynamic effect. Summary of the Invention

[0004] In view of this, the present invention provides an anti-counterfeiting element and an article having the anti-counterfeiting element, in order to solve the problems in the prior art where a single reflective facet of the anti-counterfeiting element cannot achieve a uniform distribution of the emitted light angle and the dynamic effect pattern resolution is low.

[0005] In a first aspect, the present invention provides an anti-counterfeiting element, comprising:

[0006] A substrate, wherein a feature region is provided on the surface of the substrate, and the feature region includes multiple curved surface structures;

[0007] The curved structure has a first direction and a second direction parallel to the surface of the substrate. The curved structure is bent along the first direction, and the degree of bending of the curved structure along the second direction is less than the degree of bending of the curved structure along the first direction.

[0008] Beneficial effects: By setting multiple curved surface structures in the feature area, and each curved surface structure is curved along the first direction, the emitted light from the curved surface structure can be emitted within a fan-shaped directional range under incident light in a predetermined direction. The emitted light angle distribution is more uniform, so that a single curved surface structure can achieve the effect equivalent to the combination of multiple reflective facets in the prior art. This not only achieves a higher resolution dynamic effect, but also achieves a more uniform emitted light angle distribution, resulting in a more refined and stable appearance pattern and improving the viewing angle range.

[0009] In one alternative implementation, the degree of curvature of the surface structure along the first and second directions is characterized by the slope.

[0010] In one alternative implementation, the slope distribution of the curved surface structure along the first and second directions is continuous.

[0011] Beneficial effects: By setting the slope distribution of the curved structure along the first and second directions to be continuous, there are no sharp corners on the curved structure, the emitted light angle is more uniform, the emitted light efficiency is higher, and the finished product has higher yield.

[0012] In one alternative implementation, the slope difference between at least two locations along the first direction of the curved structure is greater than 0.05.

[0013] Beneficial effect: By setting a larger difference in the slope of the curved structure along the first direction, the viewing angle of the emitted light can be improved.

[0014] In one alternative implementation, the slope difference between at least two locations along the first direction of the curved structure is greater than 0.1.

[0015] In one alternative implementation, the different surface structures have the same slope distribution range along the first direction.

[0016] Beneficial effects: By setting different curved surface structures to have the same slope distribution range along the first direction, the emitted light angle of each curved surface structure is approximately the same, resulting in higher emitted light efficiency.

[0017] In one alternative implementation, the cross sections of the different surface structures at least partially overlap along the first direction.

[0018] In one alternative implementation, the different curved surface structures have the same cross-sectional shape along the first direction.

[0019] Beneficial effect: By setting the cross-sectional shape of different curved surface structures to be the same along the first direction, production efficiency can be improved.

[0020] In one alternative embodiment, the curved structure has a convex and / or concave cross-section along the first direction.

[0021] In one alternative embodiment, the distance between the highest and lowest points of the cross section of the curved structure along the first direction is greater than 3 μm.

[0022] Beneficial effects: Since the cross section of the curved structure along the first direction is set to be convex, concave or wavy, by limiting the distance between the highest and lowest points of the cross section of the curved structure along the first direction to be greater than 3μm, the distance between the highest and lowest points will not be too small, thus preventing the unexpected diffraction effect caused by the distance being too small.

[0023] In one alternative implementation, the average slope of the curved surface structure along the second direction is a predetermined value, and the appearance of the observed feature region changes with the change of the observation position when the observation position is changed along the second direction.

[0024] Beneficial effect: By setting the average slope of the surface structure along the second direction to a predetermined value, it is possible to encode information about dynamic effects based on the average slope of the surface structure along the second direction, so that the surface structure can achieve the pre-designed dynamic effects.

[0025] In one alternative implementation, the slope difference of at least a portion of the curved structure along the second direction is less than 0.2.

[0026] Beneficial effects: By setting a smaller difference in the slope of at least a portion of the curved structure along the second direction, the viewing angle and resolution can be improved.

[0027] In one alternative implementation, the slope difference of at least a portion of the curved structure along the second direction is less than 0.05.

[0028] In one alternative implementation, the curved surface structure is generally straight along the second direction.

[0029] In one alternative embodiment, at least a portion of the plurality of surface structures are curved along the second direction.

[0030] In one optional embodiment, the direction perpendicular to the surface of the substrate is the height direction, and the maximum height difference of the curved structure along the second direction is less than the maximum height difference of the curved structure along the first direction.

[0031] In one alternative embodiment, the length of the curved structure along the second direction is less than 20 μm; and / or, the length of the curved structure along the second direction is greater than 3 μm.

[0032] Beneficial effect: By limiting the length of the curved structure along the second direction, it is possible to prevent the curved structure from being set too long along the second direction. The longer the curved structure is, the more difficult the manufacturing process becomes.

[0033] In one alternative embodiment, the direction perpendicular to the surface of the substrate is the height direction, and different curved surface structures have randomly set height differences.

[0034] Beneficial effect: By setting different surface structures with randomly set height differences, it is possible to suppress the occurrence of unexpected diffraction phenomena.

[0035] In one alternative implementation, the curved structure is at least partially covered by a metal layer;

[0036] And / or, the curved surface structure is at least partially covered by a dielectric layer;

[0037] And / or, the curved surface structure is at least partially provided with secondary microstructures;

[0038] And / or, the difference in refractive index between the materials on both sides of the curved structure is greater than 0.1.

[0039] Beneficial effects: By setting metal and dielectric layers on the curved structure, the reflectivity of the curved structure can be enhanced, and the appearance of the curved structure changing color with the viewing angle can be achieved; by limiting the difference in refractive index of the materials on both sides of the curved structure to be greater than 0.1, the refraction effect of the emitted light can be improved.

[0040] In one alternative embodiment, at least a portion of the slope difference of the surface structure along the first direction is between 1.4 times and 2.8 times the maximum average slope of the surface structure along the second direction; wherein, the slope difference refers to the maximum value of the slope difference on a plane parallel to the first direction and the height direction of the surface structure, or on a plane parallel to the second direction and the height direction of the surface structure.

[0041] In one alternative implementation, the boundaries of at least partially adjacent curved surface structures are curved.

[0042] In one alternative implementation, a portion of the boundary of the curved surface structure is set according to the contour lines of the curved surface structure.

[0043] Secondly, the present invention also provides an article having an anti-counterfeiting element, including the aforementioned anti-counterfeiting element.

[0044] Beneficial effects: Since items with anti-counterfeiting elements include the aforementioned anti-counterfeiting elements, they have the same effects as the anti-counterfeiting elements, which will not be elaborated here. Attached Figure Description

[0045] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of the structure of an anti-counterfeiting element according to an embodiment of the present invention;

[0047] Figure 2This is a structural schematic diagram of the anti-counterfeiting element along the first direction and the height direction;

[0048] Figure 3 This is a structural schematic diagram of the anti-counterfeiting element along the second direction and the height direction.

[0049] Explanation of reference numerals in the attached figures:

[0050] 1-First direction; 2-Second direction; 3-Height direction; 4-Substrate; 5-Feature area; 6-Curved surface structure. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] The following is combined Figures 1 to 3 The following describes embodiments of the present invention.

[0053] According to an embodiment of the present invention, in one aspect, an anti-counterfeiting element is provided, comprising: a substrate 4, wherein a feature region 5 is provided on the surface of the substrate 4, the feature region 5 including a plurality of curved surface structures 6; the curved surface structures 6 having a first direction 1 and a second direction 2 parallel to the surface of the substrate 4, wherein the first direction 1 and the second direction 2 respectively refer to... Figure 1 In the directions indicated by arrows 1 and 2, the curved structure 6 is bent along the first direction 1, and the degree of bending of the curved structure 6 along the second direction 2 is less than the degree of bending of the curved structure 6 along the first direction 1. By setting multiple curved structures 6 in the feature region 5, and each curved structure 6 is bent along the first direction 1, the emitted light from the curved structure 6 can be emitted within a fan-shaped directional range under incident light in a predetermined direction. The angular distribution of the emitted light is more uniform, so that a single curved structure 6 can achieve the effect equivalent to the combination of multiple reflective facets in the prior art. This not only achieves a higher resolution dynamic effect, but also achieves a more uniform angular distribution of emitted light, resulting in a more refined and stable appearance pattern and improving the viewing angle range.

[0054] like Figure 1 The figure only shows, for example, that the feature region 5 includes 9 surface structures 6. In reality, the size of a surface structure 6 is at least an order of magnitude smaller than the size of the feature region 5. There will be a considerable number of surface structures 6 in a feature region 5. The figure only uses a small number of surface structures 6 for illustration and does not represent the actual size, proportion, and quantity parameters. Figure 2 , Figure 3 All with Figure 1 The images shown are merely illustrative screenshots of several curved surface structures and do not represent actual dimensions, proportions, or quantities.

[0055] In this embodiment, the degree of curvature of the curved structure 6 along the first direction 1 and the second direction 2 is characterized by the slope. As an alternative implementation, the degree of curvature of the curved structure 6 along the first direction 1 and the second direction 2 may also be characterized by the tilt angle, or by other means.

[0056] In this design, the slope distribution of the curved surface structure 6 along the first direction 1 and the second direction 2 is continuous. By setting the slope distribution of the curved surface structure 6 along the first direction 1 and the second direction 2 to be continuous, there are no sharp corners on the curved surface structure 6, the emitted light angle is more uniform, the emitted light efficiency is higher, and the finished product has higher yield.

[0057] To improve the viewing angle of the emitted light, the slope difference between at least two locations of the curved structure 6 along the first direction 1 is greater than 0.1. As an alternative implementation, the slope difference between at least two locations of the curved structure 6 along the first direction 1 may be between 0.05 and 0.1.

[0058] In one embodiment, different curved surface structures 6 have the same slope distribution range along the first direction 1. By setting different curved surface structures 6 to have the same slope distribution range along the first direction 1, the emitted light angles of each curved surface structure 6 are approximately the same, resulting in higher emitted light efficiency. As a variation, different curved surface structures 6 may also have different slope distribution ranges along the first direction 1, or partially overlapping slope distribution ranges.

[0059] like Figure 2 As shown, the cross-sectional shape of different curved surface structures 6 along the first direction 1 can be protruding, concave, or both protruding and concave, i.e. wavy. The cross-sections of different curved surface structures 6 along the first direction 1 may partially overlap, or not overlap at all. Some cross-sectional shapes may be the same, while others may be different. The specific cross-sectional shape can be set according to actual needs, and no further restrictions are imposed here.

[0060] Since the cross-section of the curved structure 6 along the first direction 1 is designed to be convex, concave, or wavy, the distance between the highest and lowest points of the cross-section of the curved structure 6 along the first direction 1 can be set to be greater than 3 μm. This limitation ensures that the distance between the highest and lowest points of the cross-section of the curved structure 6 along the first direction 1 is not too small, preventing unintended diffraction effects. Of course, in specific settings, the distance between the highest and lowest points of the cross-section of the curved structure 6 along the first direction 1 can be set to 3.5 μm, 4 μm, 10 μm, 40 μm, etc., without further restrictions here.

[0061] The direction perpendicular to the surface of substrate 4 is the height direction 3, i.e. Figure 2 Arrow 3 indicates the direction; here, height refers to the depth of the undulations in the curved surface structure 6. Different curved surface structures 6 have randomly set height differences, which can be indicated as follows: Figure 2 Random height differences are set between different curved surface structures 6. These randomly set height differences refer to specific values ​​randomly generated by a computer. By setting different curved surface structures 6 with randomly set height differences, unexpected diffraction phenomena can be suppressed.

[0062] To suppress unwanted diffraction effects, the surface structure 6 can be arranged in an irregular grid pattern, such as a random grid shape. Different surface structures 6 can have different areas and / or different outer contour shapes, etc. To further suppress unwanted diffraction effects, random height differences are established between different surface structures 6.

[0063] In one embodiment, the average slope of the curved structure 6 along the second direction 2 is a predetermined value. When the observation position is changed along the second direction 2, the appearance of the observed feature region 5 changes with the change of observation position. By setting the average slope of the curved structure 6 along the second direction 2 to a predetermined value, information about dynamic effects can be encoded according to the average slope of the curved structure 6 along the second direction 2, so that the curved structure 6 can achieve a pre-designed dynamic effect.

[0064] In this embodiment, the slope difference of at least a portion of the curved structure 6 along the second direction 2 is less than 0.05. Here, at least a portion of the curved structure 6 along the second direction 2 can be at least 70% of the area. By setting the slope difference of at least a portion of the curved structure 6 along the second direction 2 to a smaller value, the viewing angle and resolution can be improved. Alternatively, as a variable implementation, the slope difference of at least a portion of the curved structure 6 along the second direction 2 can be between 0.05 and 0.2.

[0065] Specifically, such as Figure 3As shown, the curved surface structure 6 is approximately straight along the second direction 2. At this time, when the observation position is changed along the first direction 1 of the curved surface structure 6, the appearance of the observed feature region 5 changes less with the change of observation position than when the observation position is changed along the second direction 2 of the curved surface structure 6. At this time, the resolution of the curved surface structure 6 is the highest, and the dynamic effect of the observed feature region 5 is the best.

[0066] As an alternative implementation, at least some of the multiple curved surface structures 6 may be curved along the second direction 2. Because the contour lines of the curved surface structure 6 are curved, the boundaries of the curved surface structure 6 can be curved in the shape of the contour lines, which helps to reduce the height difference at the boundaries.

[0067] The direction perpendicular to the surface of the substrate 4 is the height direction 3. The maximum height difference of the curved structure 6 along the second direction 2 is less than the maximum height difference of the curved structure 6 along the first direction 1. That is, the degree of curvature of the curved structure 6 along the second direction 2 is less than the degree of curvature of the curved structure 6 along the first direction 1.

[0068] Specifically, the length of the curved structure 6 along the second direction 2 is greater than 3 μm and less than 20 μm. By limiting the length of the curved structure 6 along the second direction 2, it is possible to prevent the curved structure 6 from being set too long along the second direction 2. The taller the curved structure 6 is, the greater the manufacturing difficulty. As an alternative implementation, the length of the curved structure 6 along the second direction 2 can also be within other data ranges, which are not strictly limited here.

[0069] In one embodiment, covering the curved structure 6 with a metal layer and a dielectric layer can enhance the reflective effect of the curved structure 6. Specifically, at least partially covering the curved structure 6 with a metal-dielectric-metal three-layer structure can achieve an appearance that changes color with the viewing angle, such as an aluminum-silicon dioxide-chromium three-layer structure. Alternatively, covering with a dielectric-metal-dielectric three-layer structure or a multi-layer dielectric structure can also achieve a similar appearance effect. As an alternative implementation, the curved structure 6 may only be covered with a metal layer or only with a dielectric layer. As an alternative implementation, the curved structure 6 may only be partially covered with a metal layer, or a dielectric layer, or both a metal layer and a dielectric layer.

[0070] In one embodiment, the curved structure 6 is at least partially provided with secondary microstructures, such as one-dimensional or two-dimensional gratings with a period of less than 450 nanometers. By providing secondary microstructures, the color of the reflected light can be modulated, achieving an appearance effect of at least two colors at a fixed viewing angle.

[0071] In one embodiment, the difference in refractive index between the materials on both sides of the curved structure 6 is greater than 0.1. Since the difference in refractive index between the two sides of the curved structure 6 is required to achieve the light refraction effect, the materials on both sides of the curved structure 6 can refer to one side of the curved structure 6 being exposed to air, where the interface between air and resin material generally has a large difference in refractive index, or the refractive indices of the resin materials on both sides of the curved structure 6 being different. By limiting the difference in refractive index between the materials on both sides of the curved structure 6 to greater than 0.1, the refraction effect of the emitted light can be improved.

[0072] To extend the lifespan of the anti-counterfeiting components, a protective adhesive or composite protective film can also be applied to the curved structure 6.

[0073] In one embodiment, at least a portion of the slope difference of the curved surface 6 along the first direction 1 is between 1.4 and 2.8 times the maximum average slope of the curved surface 6 along the second direction 2. The slope difference refers to the maximum value of the slope difference on a cross-section drawn in a plane parallel to the first direction 1 and the height direction 3 of the curved surface 6, or on a plane parallel to the second direction 2 and the height direction 3 of the curved surface 6. The slope difference of the cross-section refers to the difference in slope between the two points on the cross-section where the slope difference is greatest; the greater the slope difference, the greater the degree of curvature.

[0074] By ensuring that the slope difference of the surface structure 6 along the first direction 1 is between 1.4 and 2.8 times the maximum average slope of the surface structure 6 along the second direction 2, consistency of the observable angle can be achieved. Since the maximum values ​​of the slopes of the surface structure 6 along the first direction 1 and the second direction 2 should be approximately the same, the slope distribution of a single surface structure 6 along the first direction 1 is approximately symmetrical. Therefore, the maximum slope of a single surface structure 6 along the first direction 1 is half the slope difference of a single surface structure 6. Different surface structures 6 have different slopes along the second direction 2, and the maximum slope along the second direction 2 is the slope of the surface structure 6 with the largest average slope along the second direction 2. Therefore, in the most ideal case, the slope difference of the surface structure 6 along the first direction 1 is twice the maximum average slope of the surface along the second direction 2. Alternatively, the slope difference along the first direction 1 can be 1.4 times, 1.5 times, 2.5 times, or 2.8 times the maximum average slope of the surface structure 6 along the second direction 2.

[0075] In one embodiment, the boundaries of at least some adjacent curved surface structures 6 are curved, which helps to reduce height fluctuations at the boundaries, reduce the total height of the curved surface structures 6, and thus reduce production difficulty. Specifically, some boundaries of the curved surface structures 6 are set according to the contour lines of the curved surface structures 6. Because the boundaries of the curved surface structures 6 are curved, and the curved surface structures 6 are set according to the contour lines at the boundaries, the edges of the curved surface structures 6 at the boundaries are of equal height. This setting can avoid height fluctuations at some edges of the curved surface structures 6.

[0076] The anti-counterfeiting element disclosed in this embodiment has the advantages of high resolution and uniform emission light angle distribution. This embodiment improves the viewing angle range by customizing the morphology of the curved surface structure 6. A single curved surface structure 6 can achieve the combined effect of multiple randomly oriented optical facets in the prior art, which can not only achieve a higher resolution dynamic effect, but also achieve a more uniform emission light angle distribution, and achieve a more refined and stable appearance pattern.

[0077] The anti-counterfeiting element disclosed in this embodiment is more difficult to forge. The surface structure 6 with its customized shape has a higher degree of freedom and requires more parameters to describe a single surface structure 6. These parameters are difficult to measure and even more difficult for counterfeiters to copy and forge.

[0078] According to an embodiment of the present invention, another aspect provides an article having an anti-counterfeiting element, including the anti-counterfeiting element described above.

[0079] In this embodiment, the item with anti-counterfeiting elements is a banknote. As an alternative implementation, the item with anti-counterfeiting elements may also be anti-counterfeiting paper, identification documents, or other valuable documents such as chip cards, checks, receipts, contracts, credit cards, etc.

[0080] In this design, part of the anti-counterfeiting element can be embedded in the banknote, while another part can be exposed. Alternatively, the anti-counterfeiting element can be pre-applied to the surface of the banknote by hot-melt adhesive, or it can be pasted onto the surface of the banknote.

[0081] Anti-counterfeiting elements can specifically include anti-counterfeiting lines, sealing tapes, anti-counterfeiting strips, anti-counterfeiting patches, labels, etc., so that they can be applied to items such as anti-counterfeiting paper and valuable documents.

[0082] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An anti-counterfeiting element, characterized in that, include: The substrate (4) has a feature region (5) on its surface, and the feature region (5) includes multiple curved surface structures (6). The curved structure (6) has a first direction (1) and a second direction (2) parallel to the surface of the substrate (4). The curved structure (6) is bent along the first direction (1). The degree of bending of the curved structure (6) along the second direction (2) is less than the degree of bending of the curved structure (6) along the first direction (1). At least part of the slope difference of the surface structure (6) along the first direction (1) is between 1.4 times and 2.8 times the maximum average slope of the surface structure (6) along the second direction (2); wherein, the slope difference of the surface structure (6) along the first direction (1) refers to the maximum value of the slope difference on the intercept line drawn on the plane parallel to the first direction (1) and the height direction (3) of the surface structure (6).

2. The anti-counterfeiting element according to claim 1, characterized in that, The degree of curvature of the curved structure (6) along the first direction (1) and the second direction (2) is characterized by the slope.

3. The anti-counterfeiting element according to claim 2, characterized in that, The slope distribution of the curved surface structure (6) along the first direction (1) and the second direction (2) is continuous.

4. The anti-counterfeiting element according to claim 2, characterized in that, The slope difference of the curved structure (6) at at least two locations along the first direction (1) is greater than 0.

05.

5. The anti-counterfeiting element according to claim 4, characterized in that, The slope difference of the curved structure (6) at at least two locations along the first direction (1) is greater than 0.

1.

6. The anti-counterfeiting element according to claim 2, characterized in that, Different surface structures (6) have the same slope distribution range along the first direction (1).

7. The anti-counterfeiting element according to claim 1, characterized in that, The cross sections of the different surface structures (6) along the first direction (1) at least partially overlap.

8. The anti-counterfeiting element according to claim 7, characterized in that, Different curved surface structures (6) have the same cross-sectional shape along the first direction (1).

9. The anti-counterfeiting element according to claim 8, characterized in that, The curved structure (6) has a convex shape and / or a concave shape in the cross section along the first direction (1).

10. The anti-counterfeiting element according to claim 8, characterized in that, The distance between the highest and lowest points of the cross section of the curved structure (6) along the first direction (1) is greater than 3 μm.

11. The anti-counterfeiting element according to any one of claims 1-10, characterized in that, The average slope of the curved surface structure (6) along the second direction (2) is a predetermined value. When the observation position is changed along the second direction (2), the appearance of the observed feature region (5) changes with the change of the observation position.

12. The anti-counterfeiting element according to claim 11, characterized in that, The slope difference of at least a portion of the curved surface structure (6) along the second direction (2) is less than 0.

2.

13. The anti-counterfeiting element according to claim 12, characterized in that, The slope difference of at least a portion of the curved surface structure (6) along the second direction (2) is less than 0.

05.

14. The anti-counterfeiting element according to claim 13, characterized in that, The curved surface structure (6) is approximately straight along the second direction (2).

15. The anti-counterfeiting element according to any one of claims 1-10, characterized in that, At least a portion of the multiple curved surface structures (6) are curved along the second direction (2).

16. The anti-counterfeiting element according to claim 15, characterized in that, The direction perpendicular to the surface of the substrate (4) is the height direction (3), and the maximum height difference of the curved structure (6) along the second direction (2) is less than the maximum height difference of the curved structure (6) along the first direction (1).

17. The anti-counterfeiting element according to any one of claims 1-10, characterized in that, The length of the curved structure (6) along the second direction (2) is less than 20 μm; and / or the length of the curved structure (6) along the second direction (2) is greater than 3 μm.

18. The anti-counterfeiting element according to any one of claims 1-10, characterized in that, The direction perpendicular to the surface of the substrate (4) is the height direction (3), and different curved structures (6) have randomly set height differences.

19. The anti-counterfeiting element according to any one of claims 1-10, characterized in that, The curved structure (6) is at least partially covered with a metal layer; And / or, the curved structure (6) is at least partially covered by a dielectric layer; And / or, the curved surface structure (6) is at least partially provided with secondary microstructures; And / or, the difference in refractive index between the materials on both sides of the curved structure (6) is greater than 0.

1.

20. The anti-counterfeiting element according to any one of claims 1-10, characterized in that, The boundaries of at least some of the adjacent curved surface structures (6) are curved.

21. The anti-counterfeiting element according to claim 20, characterized in that, Part of the boundary of the curved surface structure (6) is set according to the contour lines of the curved surface structure (6).

22. An article with anti-counterfeiting elements, characterized in that, include: The anti-counterfeiting element according to any one of claims 1 to 21.

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