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 dynamic pattern, the dynamic pattern comprising at least one bright line, the movement area of the bright line being a feature area; the feature area comprising a plurality of curved surface structures, the curved surface structure having a plurality of light coordinates parallel to the surface of the feature area, each light coordinate comprising a first direction and a second direction, and each light coordinate corresponding to a line segment on the bright line having a different curvature; the curved surface structure being curved along the first direction, and the bending degree of the curved surface structure along the second direction being less than the bending degree of the curved surface structure along the first direction. By curving the curved surface structure along the first direction, the emergent light of the curved surface structure can be emitted in a sector direction under the incidence of light in a predetermined direction, and the angle distribution of the emergent light is more uniform, so that a single curved surface structure can obtain a combined effect equivalent to a plurality of reflective facets in the prior art, and the dynamic effect of the bright line movement can be clearer.

Description

Anti-counterfeiting components and items containing anti-counterfeiting components 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 with roughly random orientations. Under incident light in a predetermined direction, the orientation of the reflective facets defines the direction of the emitted light. Changing the viewing angle in either direction creates 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 dynamic pattern, comprising at least one bright line, having an appearance that varies with the viewing angle; when the dynamic pattern is viewed in a first viewing direction, the bright line is positioned at the center of the dynamic pattern; as the anti-counterfeiting element is tilted in different directions, the bright line moves away from the center position; the area where the bright line moves is a characteristic area.

[0007] The feature region includes multiple curved surface structures, each curved surface structure having multiple optical coordinates parallel to the surface of the feature region. Each optical coordinate includes a first direction and a second direction, and each optical coordinate corresponds one-to-one with a line segment with a different curvature on the bright line. The curved surface structure is curved along the first direction, and the curvature of the curved surface structure along the second direction is less than the curvature of the curved surface structure along the first direction.

[0008] Beneficial effects: By setting multiple curved surface structures in the feature area, each curved surface structure has multiple light coordinates parallel to the surface of the feature area. Each light coordinate corresponds one-to-one with a line segment with a different curvature on the bright line. That is, the first and second directions of the light coordinates of different curved surface structures are not unified, but are determined according to the position of the bright line adjacent to the curved surface structure. By setting the curved surface structure to bend along the first direction, the emitted light of the curved surface structure 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 surface structure can achieve the effect equivalent to the combination of multiple reflective facets in the prior art. It can achieve a dynamic effect of bright line movement with higher resolution, and achieve a more refined and stable appearance pattern, thereby improving the viewing angle range.

[0009] In one optional implementation, the first direction and the second direction are respectively set at a preset angle to the tangent direction of the bright line.

[0010] Beneficial effects: By setting the first and second directions at preset angles to the tangent direction of the bright line, the observed bright line moves when the eyes change their observation position along the first and second directions, resulting in different positions of the observed bright line, thus forming binocular observation and having a stereoscopic visual effect.

[0011] In one optional implementation, the first direction is parallel to the tangential direction of the bright line, and the second direction is perpendicular to the tangential direction of the bright line.

[0012] Alternatively, the first direction is perpendicular to the tangent direction of the bright line, and the second direction is parallel to the tangent direction of the bright line.

[0013] Beneficial effect: By setting the first direction to be parallel to the tangent direction of the bright line and the second direction to be perpendicular to the tangent direction of the bright line, when the anti-counterfeiting element is tilted, the movement direction of the bright line is parallel to the tilt direction of the anti-counterfeiting element, and the observer can perceive that the bright line is suspended above the feature area or sinks below the feature area.

[0014] By setting the first direction to be perpendicular to the tangent of the bright line and the second direction to be parallel to the tangent of the bright line, when the anti-counterfeiting element is tilted, the movement direction of the bright line is perpendicular to the tilt direction of the anti-counterfeiting element, allowing the observer to perceive an unconventional visual effect.

[0015] In one optional implementation, the curved surface structure has a preset tilt direction along the second direction, and the degree of tilt of the curved surface structure along the second direction is related to the relative position of the curved surface structure and the bright line at the center.

[0016] In one alternative implementation, the degree of inclination of the curved structure along the second direction is positively correlated with the distance between the curved structure and the bright line at the center.

[0017] Beneficial effects: The degree of inclination of the curved structure along the second direction determines the width of the bright line. The greater the degree of inclination of the curved structure along the second direction, the wider the observed bright line and the lower its brightness. By setting the degree of inclination of the curved structure along the second direction to be positively correlated with the relative position of the curved structure and the bright line at the center, that is, the closer the curved structure is to the bright line at the center, the smaller the degree of inclination of the curved structure along the second direction, and the thinner and brighter the bright line; the farther the curved structure is from the bright line at the center, the greater the degree of inclination of the curved structure along the second direction, and the wider and darker the bright line.

[0018] In one alternative implementation, the degree of inclination of the curved structure along the second direction is proportional to the distance between the curved structure and the bright line at the center.

[0019] In one optional implementation, the degree of curvature of the surface structure along the first direction and the second direction is represented by the slope difference, 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.

[0020] In one alternative implementation, at least a portion of the curved surface structure has a slope difference greater than 0.05 along the first direction.

[0021] Beneficial effect: Increasing the slope difference of the curved structure along the first direction helps to improve the observable angle of the dynamic pattern.

[0022] In one alternative implementation, at least a portion of the curved surface structure has a slope difference greater than 0.1 along the first direction.

[0023] In one alternative implementation, at least a portion of the curved surface structure has a slope difference of less than 0.05 along the second direction.

[0024] Beneficial effect: Reducing the slope difference of the curved structure along the second direction helps to improve the clarity of the bright lines.

[0025] In one alternative implementation, at least a portion of the curved surface structure is generally straight along the second direction.

[0026] In one alternative implementation, at least a portion of the surface structure has a slope difference along the first direction that is greater than twice the slope difference along the second direction.

[0027] In one alternative implementation, at least a portion of the surface structure has a slope difference along the first direction that is greater than 5 times the slope difference along the second direction.

[0028] Beneficial effects: The curved structure must satisfy the condition that the curvature along the first direction is greater than the curvature along the second direction in order to distinguish the bright line. Increasing the ratio of the slope difference of the curved structure in the first direction to the slope difference of the curved structure in the second direction helps to improve the clarity of the bright line.

[0029] In one alternative implementation, 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.

[0030] Beneficial effect: By making the slope difference of the surface structure along the first direction between 1.4 times and 2.8 times the maximum average slope of the surface structure along the second direction, it is possible to achieve consistency of the observable angle.

[0031] In one alternative implementation, at least a portion of the slope difference of the surface structure along the first direction does not change with the distance between the surface structure and the bright line at the center.

[0032] Beneficial effect: By ensuring that the slope difference of the curved structure along the first direction does not change with the distance between the curved structure and the bright line at the center, the curvature of different curved structures in the first direction is roughly the same, thus ensuring the consistency of the observable angle.

[0033] In one alternative implementation, at least a portion of the slope difference of the surface structure along the first direction decreases as the distance between the surface structure and the bright line at the center increases.

[0034] Beneficial effect: As the distance between the curved structure and the bright line at the center increases, the average slope of the curved structure along the second direction increases. In order to achieve consistency of observation angle, the slope difference of the curved structure along the first direction can be appropriately reduced so that the total slope of the curved structure does not exceed the maximum expected value.

[0035] In one optional embodiment, the cross-section of the curved structure along the first direction is convex and / or concave. In another optional 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.

[0036] 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.

[0037] In one alternative implementation, adjacent curved surface structures are in a continuous wavy shape.

[0038] Beneficial effects: By making adjacent curved surface structures into continuous wavy shapes, abrupt changes in slope at the junction between adjacent curved surface structures can be avoided, which is beneficial to improving the utilization rate of light by anti-counterfeiting elements.

[0039] In one alternative implementation, the boundaries of at least partially adjacent curved surface structures are curved.

[0040] In one alternative implementation, a portion of the boundary of the curved structure is set according to the contour lines of the curved structure.

[0041] Beneficial effect: Since the boundary of the curved structure is set in a curved manner, the curved structure is set according to the contour lines of the curved structure at the boundary, so that the edge of the curved structure at the boundary is of equal height. This setting can avoid the height fluctuation at the edge of the curved structure.

[0042] In one alternative implementation, the bright line includes a straight line and / or a curve.

[0043] In one alternative embodiment, the extension length of the curved structure along the second direction is between 3 μm and 50 μm.

[0044] 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.

[0045] In one alternative implementation, the curved structure is at least partially covered by a metal layer;

[0046] And / or, the curved surface structure is at least partially covered by a dielectric layer;

[0047] And / or, the curved surface structure is at least partially provided with secondary microstructures;

[0048] And / or, the difference in refractive index between the materials on both sides of the curved structure is greater than 0.1.

[0049] 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.

[0050] In one alternative implementation, at least a portion of the feature region includes a dissipative structure, the slope of which is greater than the maximum slope of the surface structure within the anti-counterfeiting element.

[0051] Beneficial effect: In order to dissipate excess light after the formation of bright lines, by setting a dissipation structure with a large slope, some of the excess light can be dissipated to non-observation directions, thereby enhancing the uniformity of light intensity on the bright lines.

[0052] In one optional embodiment, the dynamic pattern includes at least two intersecting bright lines, and the feature regions corresponding to the two bright lines respectively include at least an overlapping region, and the overlapping region includes the curved surface structure corresponding to the two bright lines.

[0053] Secondly, the present invention also provides an article having an anti-counterfeiting element, including the aforementioned anti-counterfeiting element.

[0054] 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.

[0055] In one optional embodiment, the anti-counterfeiting element includes a first part and a second part, wherein the first part is disposed inside the article having the anti-counterfeiting element, and the second part is disposed outside the article having the anti-counterfeiting element.

[0056] Alternatively, the anti-counterfeiting element may be affixed to the surface of the article having the anti-counterfeiting element. Attached Figure Description

[0057] 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.

[0058] Figure 1 is a structural schematic diagram of an anti-counterfeiting element according to an embodiment of the present invention;

[0059] Figure 2 is a schematic diagram of the anti-counterfeiting element in the first and second directions of the first embodiment;

[0060] Figure 3 is a structural schematic diagram showing the appearance of the anti-counterfeiting element in the first embodiment;

[0061] Figure 4 is a schematic diagram of the anti-counterfeiting element in the first and second directions of the second embodiment;

[0062] Figure 5 is a structural schematic diagram showing the appearance of the anti-counterfeiting element in the second embodiment;

[0063] Figure 6 is a structural schematic diagram of the anti-counterfeiting element in the first and second directions of the third embodiment;

[0064] Figure 7 is a schematic diagram of the curved surface structure with a convex cross-section along the first direction;

[0065] Figure 8 is a schematic diagram of the curved surface structure with a wavy cross-section along the first direction;

[0066] Figure 9 is a schematic diagram of the structure where the boundaries of adjacent curved surface structures are set along contour lines.

[0067] Explanation of reference numerals in the attached figures:

[0068] 1-First direction; 2-Second direction; 3-First anti-counterfeiting element; 301-First bright line; 302-Second bright line; 303-Third bright line; 304-First feature area; 305-Second feature area; 306-Third feature area; 4-Second anti-counterfeiting element; 401-Fourth bright line; 402-Fourth feature area; 403-First view; 404-Second view; 405-Third view; 5-Third anti-counterfeiting element; 501-Fifth bright line; 502 - Fifth Feature Area; 503 - Fourth View; 504 - Fifth View; 505 - Sixth View; 6 - Fourth Anti-counterfeiting Element; 601 - Sixth Bright Line; 602 - Sixth Feature Area; 7 - Height Direction; 8 - First Curved Surface Structure; 9 - Second Curved Surface Structure; 10 - Third Curved Surface Structure; 11 - Fourth Curved Surface Structure; 12 - Fifth Curved Surface Structure; 13 - Sixth Curved Surface Structure; 14 - Seventh Curved Surface Structure; 15 - Eighth Curved Surface Structure; 16 - Boundary. Detailed Implementation

[0069] 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.

[0070] The embodiments of the present invention are described below with reference to Figures 1 to 9.

[0071] According to an embodiment of the present invention, in one aspect, an anti-counterfeiting element is provided, comprising: a dynamic pattern, the dynamic pattern including at least one bright line, the dynamic pattern having an appearance that varies with the viewing angle, when the dynamic pattern is viewed in a first viewing direction, the bright line appears at the center position of the dynamic pattern, and as the anti-counterfeiting element is tilted in different directions, the bright line moves away from the center position, the area where the bright line moves is a feature area; the feature area includes multiple curved surface structures, the curved surface structures having multiple optical coordinates parallel to the surface of the feature area, each optical coordinate including a first direction 1 and a second direction 2, each optical coordinate corresponding one-to-one with a line segment with a different curvature on the bright line; the curved surface structures are curved along the first direction 1, and the curvature of the curved surface structures along the second direction 2 is less than the curvature of the curved surface structures along the first direction 1.

[0072] By setting multiple curved surface structures in the feature area, each curved surface structure has multiple light coordinates parallel to the surface of the feature area. Each light coordinate corresponds one-to-one with a line segment with a different curvature on the bright line. That is, the first direction 1 and the second direction 2 of the light coordinates of different curved surface structures are not unified, but are determined according to the position of the bright line adjacent to the curved surface structure. By setting the curved surface structure to bend along the first direction 1, the emitted light of the curved surface structure 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 surface structure can achieve the effect equivalent to the combination of multiple reflective facets in the prior art. It can achieve a dynamic effect of bright line movement with higher resolution, and achieve a more delicate and stable appearance pattern, thereby improving the viewing angle range.

[0073] In this embodiment, the anti-counterfeiting element achieves a dynamic effect through a curved surface structure indistinguishable to the naked eye. The curved surface acts as a reflective or refracting surface, projecting light in a predetermined direction. Unlike a flat surface, which can only project light in a single observation direction, the curved surface can project light into multiple observation directions and / or at least one observation direction within a continuous angular range by adjusting its shape. The curved surface, acting as either a reflective or refracting surface, achieves the desired dynamic effect.

[0074] In this embodiment, the first direction 1 and the second direction 2 of the curved surface structure are respectively set at a preset angle to the tangent direction of the bright line. By setting the first direction 1 and the second direction 2 at a preset angle to the tangent direction of the bright line, the observed bright line moves when the eyes change their observation position along the first direction 1 and the second direction 2, resulting in different positions of the observed bright line, thus forming binocular observation and having a stereoscopic visual effect.

[0075] Specifically, as shown in Figure 2, the first direction 1 of the curved surface structure is parallel to the tangent direction of the bright line, and the second direction 2 is perpendicular to the tangent direction of the bright line. By setting the first direction 1 to be parallel to the tangent direction of the bright line and the second direction 2 to be perpendicular to the tangent direction of the bright line, when the anti-counterfeiting element is tilted, the movement direction of the bright line is parallel to the tilt direction of the anti-counterfeiting element, and the observer can perceive that the bright line is suspended above the feature area or sunk below the feature area.

[0076] Taking the second anti-counterfeiting element 4 in Figure 2 as an example, the fourth bright line 401 corresponds to the fourth feature area 402. The curved surface structures at different positions in the fourth feature area 402 have their own specific optical coordinates. The optical coordinates include the first direction 1 and the second direction 2. The optical coordinates of the curved surface structures at different positions correspond one-to-one with the line segments with different curvatures on the adjacent bright lines. The first direction 1 is parallel to the tangent direction of the adjacent fourth bright line 401, and the second direction 2 is perpendicular to the tangent direction of the adjacent fourth bright line 401.

[0077] The appearance effect of this embodiment is shown in Figure 3. In the first view 403 of the first observation position, the fourth bright line 401 of the second anti-counterfeiting element 4 is located at the center of the fourth feature area 402. Changing the observation position along different directions parallel to the surface of the second anti-counterfeiting element 4 causes the fourth bright line 401 to move within the corresponding fourth feature area 402 along different directions away from the center. Compared to the first view 403, in the second view 404, the observation position changes to the lower right, and the fourth bright line 401 moves to the upper left; in the third view 405, the observation position changes to the lower left, and the fourth bright line 401 moves to the upper right. The second anti-counterfeiting element 4 has at least two directions parallel to the surface; changing the observation position along these two directions causes the fourth bright line 401 to move. Therefore, the position of the bright line observed differs depending on the observation position of both eyes, thus creating a binocular visual effect with a stereoscopic effect.

[0078] As an alternative implementation, as shown in Figure 4, the first direction 1 is perpendicular to the tangent direction of the bright line, and the second direction 2 is parallel to the tangent direction of the bright line. By setting the first direction 1 to be perpendicular to the tangent direction of the bright line and the second direction 2 to be parallel to the tangent direction of the bright line, when the anti-counterfeiting element is tilted, the movement direction of the bright line is perpendicular to the tilt direction of the anti-counterfeiting element, allowing the observer to perceive an unconventional visual effect.

[0079] Taking the third anti-counterfeiting element 5 in Figure 4 as an example, the fifth bright line 501 corresponds to the fifth feature area 502. The curved surfaces at different positions in the fifth feature area 502 have their own specific optical coordinates. The optical coordinates include the first direction 1 and the second direction 2. The optical coordinates of the curved surface structures at different positions correspond one-to-one with the line segments with different curvatures on the adjacent bright lines. The first direction 1 is perpendicular to the tangent direction of the adjacent fifth bright line 501, and the second direction 2 is parallel to the tangent direction of the adjacent fifth bright line 501.

[0080] The appearance effect of this embodiment is shown in Figure 5. In the fourth view 503 of the first observation position, the fifth bright line 501 of the third anti-counterfeiting element 5 is located at the center of the fifth feature area 502. Changing the observation position along different directions parallel to the surface of the third anti-counterfeiting element 5 causes the fifth bright line 501 to move within the corresponding fifth feature area 502 in different directions away from the center. Compared to the fourth view 503 of the first observation position, the observation position of the fifth view 504 changes to the lower right, meaning the third anti-counterfeiting element 5 tilts to the upper left and the fifth bright line 501 moves to the upper right; the observation position of the sixth view 505 changes to the lower left, meaning the third anti-counterfeiting element 5 tilts to the upper right and the fifth bright line 501 moves to the lower right. The optical element has at least two directions parallel to the surface; changing the observation position along these two directions causes the bright line to move. Therefore, the direction of movement of the bright line is perpendicular to the direction of tilt of the optical element, creating an unconventional visual effect.

[0081] As a possible implementation, as shown in Figure 6, both the first direction 1 and the second direction 2 form a specific angle, such as an acute angle, with the tangent direction of the bright line. When the anti-counterfeiting element is tilted, the movement direction of the bright line also forms a specific angle with the tilt direction of the anti-counterfeiting element. Taking the fourth anti-counterfeiting element 6 in Figure 6 as an example, the sixth bright line 601 corresponds to the sixth feature area 602. The curved surface structures at different positions within the sixth feature area 602 have their own specific optical coordinates, including the first direction 1 and the second direction 2. The optical coordinates of the curved surface structures at different positions correspond one-to-one with the line segments with different curvatures on the adjacent sixth bright line 601, wherein the first direction 1 and the second direction 2 form specific angles with the tangent direction of the adjacent sixth bright line 601.

[0082] As shown in Figure 1, the bright lines in this embodiment include straight lines and curves. The first anti-counterfeiting element 3 in Figure 1 is a schematic diagram of a dynamic pattern, which is composed of a first bright line 301, a second bright line 302, and a third bright line 303. The first bright line 301 corresponds to the first feature area 304, the second bright line 302 corresponds to the second feature area 305, and the third bright line 303 corresponds to the third feature area 306. The combination of bright lines is not limited to this. In fact, in other embodiments, these bright lines can have other shapes, can form dynamic patterns on their own, and can form other dynamic patterns with other bright lines or even bright lines with other effects. No further restrictions are imposed here.

[0083] Depending on the needs of the dynamic pattern design, the bright lines can be straight lines, such as the second bright line 302; they can also be curves, such as the first bright line 301; or they can be a mixture of curves and straight lines, such as the third bright line 303. Different positions on the same bright line can have different curvatures, such as the first bright line 301; different positions on the same bright line can have different bending directions, such as the third bright line 303; bright lines can have inflection points, such as the third bright line 303; bright lines can be unconnected at the beginning and end, such as the second bright line 302 and the third bright line 303; or they can be connected at the beginning and end, such as the second bright line 302; bright lines can intersect, such as the first bright line 301 and the second bright line 302 intersecting, and the first feature area 304 of the first bright line 301 and the second feature area 305 of the second bright line 302 also intersecting. In the overlapping area, there is a mixture of curved surface structures corresponding to the first bright line 301 and the curved surface structures corresponding to the second bright line 302.

[0084] For designs with special dynamic patterns, bright lines can also be used to create a variety of dynamic patterns through various shapes and combinations, such as numbers, letters, Chinese characters, simple drawings, and geometric shapes.

[0085] In one embodiment, a dynamic pattern with two bright lines moving in opposite directions creates a stronger dynamic contrast.

[0086] The degree of curvature of the curved surface structure along the first direction 1 and the second direction 2 is represented by the slope difference. The slope difference refers to the maximum difference in slope between two points on the cross-section parallel to the first direction 1 and the height direction 7 of the curved surface structure, or between two points on the cross-section parallel to the second direction 2 and the height direction 7 of the curved surface structure. The greater the slope difference, the greater the degree of curvature.

[0087] The curved surface structure has a predetermined tilt direction along the second direction 2, and the degree of tilt of the curved surface structure along the second direction 2 is related to the relative position of the curved surface structure and the bright line at the center position. Specifically, the degree of tilt of the curved surface structure along the second direction 2 is positively correlated with the distance between the curved surface structure and the bright line at the center position. Further, the degree of tilt of the curved surface structure along the second direction 2 is proportional to the distance between the curved surface structure and the bright line at the center position. Here, the degree of tilt of the curved surface structure along the second direction 2 refers to the degree of tilt of the cross section of the curved surface structure in a plane parallel to the second direction 2 and the height direction 7, which can be represented by the average slope of the cross section of the curved surface structure in a plane parallel to the second direction 2 and the height direction 7.

[0088] The degree of inclination of the curved structure along the second direction 2 determines the width of the bright line. The greater the degree of inclination of the curved structure along the second direction 2, the wider the observed bright line and the lower its brightness. By setting the degree of inclination of the curved structure along the second direction 2 to be positively correlated with the relative position of the curved structure and the bright line at the center, that is, the closer the curved structure is to the bright line at the center, the smaller the degree of inclination of the curved structure along the second direction 2, and the brighter and thinner the bright line. The farther the curved structure is from the bright line at the center, the greater the degree of inclination of the curved structure along the second direction 2, and the wider and darker the bright line.

[0089] To improve the viewing angle of the emitted light, the slope difference between at least two locations of the curved structure 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 along the first direction 1 may be between 0.05 and 0.1.

[0090] To improve the clarity of the bright lines, the slope difference of at least a portion of the curved surface structure along the second direction 2 is less than 0.05. Specifically, the curved surface structure is approximately straight along the second direction 2. That is, the cross-section of the curved surface structure in a plane parallel to the second direction 2 and the height direction 7 is straight. This straightness is not absolute in a mathematical sense; small undulations relative to a straight line are allowed. For optical reflection or refraction, undulations less than a quarter wavelength of optical path difference can be ignored and considered straight. As an alternative implementation, the slope difference of the curved surface structure along the second direction 2 can be between 0.05 and 0.2.

[0091] In one embodiment, the slope difference of at least a portion of the curved surface structure along the first direction 1 is greater than twice the slope difference of the curved surface structure along the second direction 2. Specifically, the slope difference of at least a portion of the curved surface structure along the first direction 1 is greater than five times the slope difference of the curved surface structure along the second direction 2. Since the curved surface structure needs to satisfy the condition that the curvature along the first direction 1 is greater than the curvature along the second direction 2 in order to distinguish the bright line, increasing the ratio of the slope difference of the curved surface structure along the first direction 1 to the slope difference of the curved surface structure along the second direction 2 helps to improve the clarity of the bright line. As an alternative implementation, the slope difference of at least a portion of the curved surface structure along the first direction 1 may also be greater than three times or four times the slope difference of the curved surface structure along the second direction 2.

[0092] In one embodiment, the slope difference of at least a portion of the surface structure along the first direction 1 is between 1.4 and 2.8 times the maximum average slope of the surface structure along the second direction 2. By ensuring that the slope difference of the surface structure along the first direction 1 is between 1.4 and 2.8 times the maximum average slope of the surface structure along the second direction 2, consistency of the observable angle can be achieved. Since the maximum values ​​of the slopes of the surface structures in the first direction 1 and the second direction 2 should be approximately the same, the slope distribution of a single surface structure in the first direction 1 is approximately symmetrical. Therefore, the maximum slope of a single surface structure in the first direction 1 is half the slope difference of the single surface structure. Different surface structures have different slopes in the second direction 2, and the maximum slope in the second direction 2 is the slope of the surface structure with the largest average slope in the second direction 2. Therefore, in the most ideal case, the slope difference of the surface structure in the first direction 1 is twice the maximum average slope of the surface in the second direction 2. As an alternative implementation, the slope difference of the surface 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 along the second direction 2.

[0093] In one embodiment, the slope difference of at least a portion of the curved structure along the first direction 1 does not change with the distance between the curved structure and the bright line at the center. By ensuring that the slope difference of the curved structure along the first direction 1 does not change with the distance between the curved structure and the bright line at the center, the curvature of different curved structures in the first direction 1 is approximately the same, ensuring consistency of the observable angle. As an alternative implementation, the slope difference of at least a portion of the curved structure along the first direction 1 may decrease as the distance between the curved structure and the bright line at the center increases. Since the average slope of the curved structure along the second direction 2 increases as the distance between the curved structure and the bright line at the center increases, in order to achieve consistency of the observable angle, the slope difference of the curved structure along the first direction 1 can be appropriately reduced so that the total slope of the curved structure does not exceed the maximum expected value.

[0094] As shown in Figure 7, the cross-section of a single curved surface structure along the first direction 1 is a convex shape. It should be noted that this schematic diagram is for illustrative purposes only and does not represent actual dimensions, proportions, or quantities. In reality, the size of a curved surface structure is at least an order of magnitude smaller than the size of the feature region, and a feature region may contain a considerable number of curved surface structures. The schematic diagram only uses a small number of curved surface structures for illustration. Furthermore, while the boundary of the curved surface structure in the schematic diagram is parallel to either the first direction 1 or the second direction 2, in reality, the boundary of the curved surface structure may not be parallel to either direction 1 or direction 2, and may be polygonal or have curved boundaries. The first curved surface structure 8, the second curved surface structure 9, and the third curved surface structure 10 are examples where there is only one convexity along the first direction 1. The first curved surface structure 8 is located near the bright line at the center position, and its inclination along the second direction 2 is basically not inclined or has a very small inclination. The third curved surface structure 10 is located at the edge of the feature region, and its inclination along the second direction 2 is the greatest. This inclination can be represented by the inclination angle or slope. From the first curved surface structure 8 to the third curved surface structure 10, that is, as the distance between the curved surface structure and the bright line at the center position increases, the inclination of the curved surface structure in the second direction 2 becomes greater. As an alternative implementation, the cross-section of the curved surface structure along the first direction 1 may be concave.

[0095] As an alternative implementation, at least some of the curved structures may have a cross-section along the first direction 1 that includes both convex and concave shapes, i.e., wavy. Figure 8 is a schematic diagram of this embodiment. It should be noted that this schematic diagram is for illustration only and does not represent actual dimensions, proportions, or quantities. In reality, the size of a curved structure is at least an order of magnitude smaller than the size of the feature region, and a feature region may contain a considerable number of curved structures, while the schematic diagram only uses a small number of curved structures for illustration. Also, in the schematic diagram, the boundary of the curved structure is parallel to the first direction 1 or the second direction 2. In reality, the boundary of the curved structure may not be parallel to the first direction 1 or the second direction 2, and may be polygonal or have curved boundaries. The fourth curved structure 11, the fifth curved structure 12, and the sixth curved structure 13 are examples of wavy cross-sections along the first direction 1. The fourth curved structure 11 is located near the bright line at the center position, and its inclination along the second direction 2 is basically not inclined or very small. The sixth curved structure 13 is located at the edge of the feature region, and its inclination along the second direction 2 is the greatest. From the fourth surface structure 11 to the sixth surface structure 13, that is, as the distance to the bright line at the center position increases, the degree of inclination of the surface structure along the second direction 2 increases.

[0096] In this embodiment, the adjacent curved surface structures are in a continuous wave shape, which can avoid abrupt changes in slope at the junction of adjacent curved surface structures. As shown in Figure 8, the slope at the junction between adjacent curved surface structures along the first direction 1 is continuous. This setting is beneficial to improving the utilization rate of light by the anti-counterfeiting element.

[0097] In this design, the distance between the highest and lowest points of the cross-section of the curved structure along the first direction 1 is greater than 3 μm, and the extension length of the curved structure along the second direction 2 is between 3 μm and 50 μm. Since the cross-section of the curved structure along the first direction 1 is designed to be convex, concave, or wavy, limiting the distance between the highest and lowest points of the cross-section along the first direction 1 to be greater than 3 μm prevents the distance from being too small, thus avoiding unintended diffraction effects. Limiting the length of the curved structure along the second direction 2 prevents it from becoming too long; a longer curved structure increases manufacturing complexity. 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 limitations here.

[0098] In one embodiment, at least some of the adjacent curved surface structures have curved boundaries 16, which helps to reduce height fluctuations at the boundaries 16, decrease the total height of the curved surface structure, and thus reduce production difficulty. Specifically, a portion of the curved surface structure's boundaries 16 are set according to the contour lines of the curved surface structure. Because the curved boundaries 16 of the curved surface structure are set according to the contour lines of the curved surface structure at the boundaries 16, the edges of the curved surface structure at the boundaries 16 are of equal height. This arrangement can avoid height fluctuations at the edges of the curved surface structure.

[0099] Figure 9 is a schematic diagram showing the boundaries 16 of the seventh curved surface structure 14 and the eighth curved surface structure 15 within the feature area of ​​the anti-counterfeiting element. Boundary 16 is set according to the contour lines of the seventh curved surface structure 14, meaning the edges of the seventh curved surface structure 14 on boundary 16 are at the same height. Compared to setting boundary 16 according to a straight line shape, this setting avoids height fluctuations at the edges of the curved surface structures. It should be noted that the small squares in Figure 9 are only for easy identification of the boundaries 16 of adjacent curved surface structures being set along contour lines and have no other practical meaning.

[0100] The seventh surface structure 14 and the eighth surface structure 15 are adjacent surface structures. Since the size of the surface structure is much smaller than the size of the feature region, the difference in distance from the seventh surface structure 14 and the eighth surface structure 15 to the bright line at the center position is very small. Therefore, the difference in the degree of inclination of the seventh surface structure 14 and the eighth surface structure 15 in the second direction 2 is also very small.

[0101] In one embodiment, covering the curved structure with a metal layer and a dielectric layer can enhance the reflective effect of the curved structure. Specifically, at least partially covering the curved structure 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. Similarly, covering with a dielectric-metal-dielectric three-layer structure or a multi-layer dielectric structure can also achieve a similar appearance effect. As a variation of the implementation, the curved structure may only be covered with a metal layer, or only with a dielectric layer. As another variation of the implementation, the curved structure may only be partially covered with a metal layer, or a dielectric layer, or both.

[0102] In one embodiment, the curved surface structure 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.

[0103] In one embodiment, the difference in refractive index between the materials on both sides of the curved structure is greater than 0.1. Since a difference in refractive index is required between the two sides of the curved structure to achieve the light refraction effect, the materials on both sides of the curved structure can refer to one side of the curved structure being exposed to air. Generally, the interface between air and resin materials has a large difference in refractive index, or the refractive indices of the resin materials on both sides of the curved structure are different. By limiting the difference in refractive index between 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.

[0104] To extend the lifespan of anti-counterfeiting components, protective adhesive or composite protective film can also be applied to the curved surface.

[0105] In one embodiment, at least a portion of the feature region includes a dissipative structure, the slope of which is greater than the maximum slope of the curved surface structure within the anti-counterfeiting element. This dissipative structure can be a curved surface or a flat surface, as long as its slope is greater than the maximum slope of other curved surface structures within the anti-counterfeiting element; no further restrictions are imposed. To dissipate excess light after the formation of a bright line, a dissipative structure with a large slope can dissipate some of the excess light to a non-observational direction, thereby enhancing the uniformity of light intensity along the bright line.

[0106] 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. A single curved surface structure can achieve the combined effect of multiple randomly oriented optical facets in the prior art. This not only enables a higher resolution dynamic effect, but also a more uniform emission light angle distribution, resulting in a more refined and stable appearance pattern.

[0107] The anti-counterfeiting element disclosed in this embodiment is more difficult to forge, has a higher degree of freedom in its customized surface structure, and requires more parameters to describe a single surface structure. These parameters are difficult to measure and even more difficult for counterfeiters to copy and forge.

[0108] 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.

[0109] 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.

[0110] The anti-counterfeiting element includes a first part and a second part, with the first part located inside the banknote and the second part located on the outside of the banknote. Alternatively, the anti-counterfeiting element can be pre-applied to the surface of the banknote by hot-melt adhesive, or it can be affixed to the surface of the banknote.

[0111] 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.

[0112] 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 dynamic pattern includes at least one bright line and has an appearance that varies with the viewing angle. When the dynamic pattern is viewed in a first viewing direction, the bright line appears at the center of the dynamic pattern. As the anti-counterfeiting element is tilted in different directions, the bright line moves away from the center position. The area where the bright line moves is a feature area. The feature area includes multiple curved surface structures. The curved surface structures have multiple light coordinates parallel to the surface of the feature area. Each light coordinate includes a first direction (1) and a second direction (2). Each light coordinate corresponds one-to-one with a line segment with a different curvature on the bright line. The curved surface structure is curved along the first direction (1). The curvature of the curved surface structure along the second direction (2) is less than the curvature of the curved surface structure along the first direction (1).

2. The anti-counterfeiting element according to claim 1, characterized in that, The first direction (1) and the second direction (2) are respectively set at a preset angle to the tangent direction of the bright line.

3. The anti-counterfeiting element according to claim 2, characterized in that, The first direction (1) is parallel to the tangent direction of the bright line, and the second direction (2) is perpendicular to the tangent direction of the bright line; or, the first direction (1) is perpendicular to the tangent direction of the bright line, and the second direction (2) is parallel to the tangent direction of the bright line.

4. The anti-counterfeiting element according to claim 1, characterized in that, The curved structure has a preset tilt direction along the second direction (2), and the degree of tilt of the curved structure along the second direction (2) is related to the relative position of the curved structure and the bright line at the center.

5. The anti-counterfeiting element according to claim 4, characterized in that, The degree of inclination of the curved structure along the second direction (2) is positively correlated with the distance between the curved structure and the bright line at the center.

6. The anti-counterfeiting element according to claim 5, characterized in that, The degree of inclination of the curved structure along the second direction (2) is proportional to the distance between the curved structure and the bright line at the center.

7. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, The degree of curvature of the curved structure along the first direction (1) and the second direction (2) is represented by the slope difference, wherein the slope difference refers to the maximum value of the slope difference on the first section line drawn on the plane parallel to the first direction (1) and the height direction (7) of the curved structure; or, the maximum value of the slope difference on the second section line drawn on the plane parallel to the second direction (2) and the height direction (7) of the curved structure.

8. The anti-counterfeiting element according to claim 7, characterized in that, At least part of the surface structure has a slope difference greater than 0.05 along the first direction (1).

9. The anti-counterfeiting element according to claim 8, characterized in that, At least part of the surface structure has a slope difference greater than 0.1 along the first direction (1).

10. The anti-counterfeiting element according to claim 7, characterized in that, At least part of the surface structure has a slope difference of less than 0.05 along the second direction (2).

11. The anti-counterfeiting element according to claim 10, characterized in that, At least part of the surface structure is generally straight along the second direction (2).

12. The anti-counterfeiting element according to claim 7, characterized in that, At least part of the surface structure has a slope difference along the first direction (1) that is greater than twice the slope difference along the second direction (2).

13. The anti-counterfeiting element according to claim 12, characterized in that, At least part of the surface structure has a slope difference along the first direction (1) that is greater than 5 times the slope difference along the second direction (2).

14. The anti-counterfeiting element according to claim 7, characterized in that, The slope difference of at least part of the surface structure along the first direction (1) is between 1.4 times and 2.8 times the maximum average slope of the surface structure along the second direction (2).

15. The anti-counterfeiting element according to claim 7, characterized in that, At least part of the slope difference of the surface structure along the first direction (1) does not change with the distance between the surface structure and the bright line at the center.

16. The anti-counterfeiting element according to claim 7, characterized in that, At least part of the slope difference of the surface structure along the first direction (1) decreases as the distance between the surface structure and the bright line at the center increases.

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

18. The anti-counterfeiting element according to claim 17, characterized in that, The distance between the highest and lowest points of the cross section of the curved structure along the first direction (1) is greater than 3 μm.

19. The anti-counterfeiting element according to claim 17, characterized in that, The adjacent curved surface structures are in a continuous wave-like shape.

20. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, At least some of the adjacent boundaries (16) of the curved surface structures are curved.

21. The anti-counterfeiting element according to claim 20, characterized in that, The boundary (16) of the curved surface structure is set according to the contour lines of the curved surface structure.

22. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, The bright lines include straight lines and / or curves.

23. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, The length of the curved structure along the second direction (2) is between 3 μm and 50 μm.

24. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, The curved structure is at least partially covered by a metal layer; and / or, the curved structure is at least partially covered by a dielectric layer; and / or, the curved structure 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 is greater than 0.

1.

25. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, At least a portion of the feature region includes a dissipative structure, the slope of which is greater than the maximum slope of the surface structure within the anti-counterfeiting element.

26. The anti-counterfeiting element according to any one of claims 1-6, characterized in that, The dynamic pattern includes at least two intersecting bright lines, and the feature regions corresponding to the two bright lines each include at least an overlapping region, and the overlapping region includes the curved surface structure corresponding to the two bright lines.

27. An article with anti-counterfeiting elements, characterized in that, include: The anti-counterfeiting element according to any one of claims 1 to 26.

28. The article with anti-counterfeiting elements according to claim 27, characterized in that, The anti-counterfeiting element includes a first part and a second part, wherein the first part is disposed inside the article having the anti-counterfeiting element, and the second part is disposed outside the article having the anti-counterfeiting element; or, the anti-counterfeiting element is affixed to the surface of the article having the anti-counterfeiting element.

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