Security element and article with security element

Abstract

The invention relates to the technical field of anti-counterfeiting, and discloses an anti-counterfeiting element, which comprises a dynamic pattern, the dynamic pattern comprises at least one bright line, and a region where the bright line moves is a feature region; the feature region comprises a plurality of curved surface structures, each curved surface structure has a plurality of light coordinates parallel to the surface of the feature region, each light coordinate comprises a first direction and a second direction, and each light coordinate is in one-to-one correspondence with line segments with different curvatures on the bright line; the curved surface structure is bent in the first direction, and the bending degree of the curved surface structure in the second direction is smaller than that of the curved surface structure in the first direction. The curved surface structure is bent along the first direction, so that the emergent light of the curved surface structure can be emitted in a fan-shaped direction range under the incident light in the preset direction, and the angle distribution of the emergent light is more uniform, that is, the single curved surface structure can obtain a combined effect equivalent to that of a plurality of reflective facets in the prior art; and the dynamic effect of bright line movement is clearer.

Description

Technical Field

[0001] The present invention relates to the field of anti-counterfeiting technology, and in particular to an anti-counterfeiting element and an article having the anti-counterfeiting element. Background Art

[0002] In order to prevent counterfeiting through scanning and copying, optical anti-counterfeiting technology is widely used in various high-security or high-value-added printed materials such as banknotes, cards and product packaging, and has achieved very good results.

[0003] The prior art discloses an anti-counterfeiting element, which includes a plurality of reflective facets, and the orientations of different reflective facets are roughly randomly distributed. Under incident light of a predetermined direction, the orientation of the reflective facets defines the direction of the outgoing light, and changes in the viewing angle in two directions have a dynamic effect in which the appearance changes with the viewing angle. However, the anti-counterfeiting element needs to use a plurality of reflective facets to form a large area to achieve a uniform distribution of the outgoing light angle, and the combination of the plurality of reflective facets will also reduce 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 to solve the problem in the prior art that a single reflective facet of the anti-counterfeiting element cannot achieve uniform distribution of the angle of the emitted light and the pattern resolution of the dynamic effect is low.

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

[0006] A dynamic pattern, wherein the dynamic pattern comprises at least one bright line, and the dynamic pattern has an appearance that changes with the observation angle. When the dynamic pattern is observed in a first observation direction, the bright line appears at the center of the dynamic pattern. When the anti-counterfeiting element is tilted in different directions, the bright line moves away from the center, and the area where the bright line moves is the characteristic area.

[0007] The characteristic area includes a plurality of curved surface structures, each of which has a plurality of optical coordinates parallel to a surface of the characteristic area, each of the optical coordinates includes a first direction and a second direction, and each of the optical coordinates corresponds one-to-one to a line segment with a different curvature on the bright line; the curved surface structure is curved along the first direction, and a degree of curvature of the curved surface structure along the second direction is less than a degree of curvature of the curved surface structure along the first direction.

[0008] Beneficial effect: by setting a plurality of curved surface structures on the characteristic area, the curved surface structures have a plurality of optical coordinates parallel to the surface of the characteristic area, each optical coordinate corresponds one-to-one to a line segment with a different curvature on the bright line, that is, the first direction and the second direction of the optical 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, and by setting the curved surface structure to be curved along the first direction, under the incident light in a predetermined direction, the emergent light of the curved surface structure can be emitted within a fan-shaped direction range, and the angle distribution of the emergent light is more uniform, that is, a single curved surface structure can obtain a combined effect equivalent to a plurality of reflective small faces in the prior art, and can achieve a dynamic effect of bright line movement with a higher resolution, and achieve a more refined and stable appearance pattern, thereby improving the viewing angle range.

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

[0010] Beneficial effect: By setting the first direction and the second direction at a preset angle to the tangent direction of the bright line, when the two eyes change the observation position along the first direction and the second direction, the observed bright line moves, so that the position of the observed bright line is different, thereby forming binocular observation with a three-dimensional visual effect.

[0011] In an optional implementation, the first direction is parallel to the tangent direction of the bright line, and the second direction is perpendicular to the tangent 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 tilting direction of the anti-counterfeiting element, and the observer can feel that the bright line is suspended above the characteristic area or sinks below the characteristic area;

[0014] By setting the first direction perpendicular to the tangent direction of the bright line and the second direction 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 tilting direction of the anti-counterfeiting element, and the observer can feel an unconventional visual effect.

[0015] In an optional implementation, the curved surface structure has a preset inclination direction along the second direction, and the inclination degree 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 an optional implementation, the inclination degree of the curved surface structure along the second direction is positively correlated with the distance between the curved surface structure and the bright line at the center.

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

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

[0019] In an optional embodiment, the degree of curvature of the curved structure along the first direction and the second direction is represented by a slope difference, wherein the slope difference refers to a maximum value of the difference in slopes on a section drawn on a plane parallel to the first direction and the height direction of the curved structure, or a section drawn on a plane parallel to the second direction and the height direction of the curved structure.

[0020] In an optional implementation, the slope difference of at least part of the curved surface structure along the first direction is greater than 0.05.

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

[0022] In an optional implementation, the slope difference of at least part of the curved surface structure along the first direction is greater than 0.1.

[0023] In an optional implementation, the slope difference of at least part of the curved surface structure along the second direction is less than 0.05.

[0024] Beneficial effect: reducing the slope difference of the curved surface structure along the second direction is helpful to improve the clarity of the bright line.

[0025] In an optional embodiment, at least a portion of the curved structure is substantially straight along the second direction.

[0026] In an optional implementation, the slope difference of at least part of the curved surface structures along the first direction is greater than twice the slope difference of the curved surface structures along the second direction.

[0027] In an optional implementation, the slope difference of at least part of the curved surface structures along the first direction is greater than 5 times the slope difference of the curved surface structures along the second direction.

[0028] Beneficial effect: The curved surface structure must satisfy that the curvature along the first direction is greater than the curvature along the second direction, so that the bright line can be distinguished. By increasing the ratio of the slope difference of the curved surface structure in the first direction to the slope difference of the curved surface structure in the second direction, the clarity of the bright line can be improved.

[0029] In an optional implementation, the slope difference of at least part of the curved surface structure along the first direction is between 1.4 times and 2.8 times the maximum average slope of the curved surface structure along the second direction.

[0030] Beneficial effect: By setting the slope difference of the curved surface structure along the first direction to between 1.4 and 2.8 times the maximum average slope of the curved surface structure along the second direction, consistency of observable angles can be achieved.

[0031] In an optional implementation, the slope difference of at least part of the curved surface structure along the first direction does not change with the distance between the curved surface structure and the bright line at the center.

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

[0033] In an optional implementation, the slope difference of at least part of the curved surface structure along the first direction decreases as the distance between the curved surface structure and the bright line at the center increases.

[0034] Beneficial effect: Since the average slope of the curved structure along the second direction increases as the distance between the curved structure and the bright line at the center increases, in order to achieve consistency in the viewing 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 expectation.

[0035] In an optional embodiment, the cross section of the curved surface structure along the first direction is convex and / or concave. In an optional embodiment, the distance between the highest point and the lowest point of the cross section of the curved surface structure along the first direction is greater than 3 μm.

[0036] Beneficial effect: Since the cross-section of the curved surface structure along the first direction is set to be convex, concave or wavy, by limiting the distance between the highest point and the lowest point of the cross-section of the curved surface structure along the first direction to be greater than 3μm, the distance between the highest point and the lowest point will not be too small, thereby preventing the distance from being too small to produce unexpected diffraction effects.

[0037] In an optional implementation, the adjacent curved surface structures are in a continuous wave shape.

[0038] Beneficial effect: By making adjacent curved surface structures into continuous wave shapes, it is possible to avoid sudden changes in slope at the junctions between adjacent curved surface structures, which is beneficial to improving the utilization rate of light by the anti-counterfeiting element.

[0039] In an optional embodiment, at least some of the boundaries of the adjacent curved surface structures are curved.

[0040] In an optional implementation, part of the boundary of the curved surface structure is arranged according to the contour lines of the curved surface structure.

[0041] Beneficial effect: Since the boundary of the curved surface structure is set in a curved shape, the curved surface structure is set at the boundary according to the contour lines of the curved surface structure, so that the edges of the curved surface structure at the boundary are of the same height. This setting can avoid height fluctuation at the edges of the curved surface structure.

[0042] In an optional implementation, the bright line includes a straight line and / or a curved line.

[0043] In an optional implementation, an 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 surface structure along the second direction, it is possible to prevent the curved surface structure from being too long along the second direction. The longer the curved surface structure is, the higher it is, and the more difficult the production process is.

[0045] In an optional embodiment, the curved surface structure is at least partially covered with a metal layer;

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

[0047] and / or, the curved surface structure is at least partially provided with a secondary microstructure;

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

[0049] Beneficial effects: By arranging a metal layer and a dielectric layer on the curved surface structure, the reflection effect of the curved surface structure can be enhanced, and the appearance of the curved surface structure changing color with the observation angle can be achieved; by limiting the difference in refractive index of the materials on both sides of the curved surface structure to be greater than 0.1, the refraction effect of the outgoing light can be improved.

[0050] In an optional embodiment, at least part of the characteristic area includes at least part of a dissipative structure, and the slope of the dissipative structure is greater than the maximum slope of the curved surface structure in the anti-counterfeiting element.

[0051] Beneficial effect: In order to dissipate the excess light after the bright line is formed, a dissipation structure with a larger slope can be set to dissipate part of the excess light to the non-observation direction, thereby enhancing the uniformity of the light intensity on the bright line.

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

[0053] In a second aspect, the present invention further provides an article with an anti-counterfeiting element, comprising: the anti-counterfeiting element described above.

[0054] Beneficial effect: Because the article with the anti-counterfeiting element includes the above-mentioned anti-counterfeiting element, it has the same effect as the anti-counterfeiting element, which will not be described in detail here.

[0055] In an optional embodiment, the anti-counterfeiting element includes a first part and a second part, the first part is arranged inside the article with the anti-counterfeiting element, and the second part is arranged outside the article with the anti-counterfeiting element;

[0056] Alternatively, the anti-counterfeiting element is attached to the surface of the article having the anti-counterfeiting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

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

[0059] Figure 2 A schematic diagram of the structure of the anti-counterfeiting element of the first embodiment in the first direction and the second direction;

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

[0061] Figure 4 A schematic diagram of the structure of the anti-counterfeiting element of the second embodiment in the first direction and the second direction;

[0062] Figure 5 A schematic diagram of the structure of the anti-counterfeiting element of the second embodiment showing the appearance effect;

[0063] Figure 6 A schematic diagram of the structure of the anti-counterfeiting element of the third embodiment in the first direction and the second direction;

[0064] Figure 7 is a schematic diagram of a structure in which a cross section of a curved structure along a first direction is convex;

[0065] Figure 8 is a schematic structural diagram of a curved structure in which a cross section along a first direction is wavy;

[0066] Fig. 9 Schematic diagram of the structure set along the contour lines of the boundaries of adjacent surface structures.

[0067] Description of reference numerals:

[0068] 1-first direction; 2-second direction; 3-first security element; 301-first bright line; 302-second bright line; 303-third bright line; 304-first characteristic area; 305-second characteristic area; 306-third characteristic area; 4-second security element; 401-fourth bright line; 402-fourth characteristic area; 403-first view; 404-second view; 405-third view; 5-third security element; 501-fifth bright line; 502-fifth characteristic area; 503-fourth view; 504-fifth view; 505-sixth view; 6-fourth anti-counterfeiting element; 601-sixth bright line; 602-sixth characteristic 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 DESCRIPTION

[0069] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0070] Combine the following Figures 1 to 9 , describing an embodiment of the present invention.

[0071] According to an embodiment of the present invention, on the one hand, a security element is provided, including: a dynamic pattern, the dynamic pattern including at least one bright line, the dynamic pattern having an appearance that changes with the observation angle, when the dynamic pattern is observed in a first observation direction, the bright line appears at the center of the dynamic pattern, and when the security element is tilted in different directions, the bright line moves away from the center, and the area where the bright line moves is a characteristic area; the characteristic area includes a plurality of curved surface structures, the curved surface structures have a plurality of optical coordinates parallel to the surface of the characteristic area, each optical coordinate includes a first direction 1 and a second direction 2, and each optical coordinate corresponds one-to-one to a line segment with a different curvature on the bright line; the curved surface structure is curved along the first direction 1, and the degree of curvature of the curved surface structure along the second direction 2 is less than the degree of curvature of the curved surface structure along the first direction 1.

[0072] By arranging a plurality of curved surface structures in a characteristic region, the curved surface structures have a plurality of optical coordinates parallel to the surface of the characteristic region, and each optical coordinate corresponds one-to-one to a line segment with a different curvature on the bright line, that is, the first direction 1 and the second direction 2 of the optical coordinates of different curved surface structures are not uniform, but are determined according to the position of the bright line adjacent to the curved surface structure. By arranging the curved surface structure in a curved manner along the first direction 1, under incident light in a predetermined direction, the emergent light of the curved surface structure can be emitted within a fan-shaped direction range, and the angle distribution of the emergent light is more uniform, that is, a single curved surface structure can obtain a combined effect equivalent to a plurality of reflective small faces in the prior art, and can achieve a dynamic effect of bright line movement with a higher resolution, and achieve a more refined and stable appearance pattern, thereby improving the viewing angle range.

[0073] The anti-counterfeiting element in this embodiment achieves a dynamic effect through a curved surface structure that is indistinguishable to the naked eye. The curved surface structure acts as a reflective surface or a refracting surface of light, and projects the light in a predetermined direction. Unlike a flat surface that can only project light to a single viewing direction as a reflective surface or a refracting surface, by setting the morphology of the surface of the curved surface structure, the light can be projected to multiple viewing directions and / or at least one viewing direction within a continuous angle range. The curved surface structure can achieve the expected dynamic effect as a reflective surface or a refracting surface.

[0074] In this embodiment, the first direction 1 and the second direction 2 of the curved 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 to the tangent direction of the bright line at a preset angle, when the two eyes change the observation position along the first direction 1 and the second direction 2, the observed bright line moves, so that the position of the observed bright line is different, thereby forming binocular observation with a three-dimensional visual effect.

[0075] Specifically, Figure 2 As shown, the first direction 1 of the curved 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 tilting direction of the anti-counterfeiting element, and the observer can feel that the bright line is suspended above the feature area or sinks below the feature area.

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

[0077] The appearance of this embodiment is as follows Figure 3 As shown, in the first view 403 of the second security element 4 at the first observation position, the fourth bright line 401 is located at the center of the fourth characteristic area 402. When the observation position is changed along different directions parallel to the surface of the second security element 4, the fourth bright line 401 moves in the corresponding fourth characteristic area 402 along different directions away from the center position. Compared with the first view 403, the observation position of the second view 404 is changed to the lower right, and the fourth bright line 401 moves to the upper left; the observation position of the third view 405 is changed to the lower left, and the fourth bright line 401 moves to the upper right. The second security element 4 has at least two directions parallel to the surface, and the fourth bright line 401 will move when the observation position is changed along these two directions. As a result, the observation positions of the two eyes are different, and the positions of the observed bright lines are also different, thereby forming a binocular inspection with a three-dimensional visual effect.

[0078] As a convertible implementation method, it can also be, Figure 4As shown, 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 tilting direction of the anti-counterfeiting element, and the observer can feel an unconventional visual effect.

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

[0080] The appearance of this embodiment is as follows Figure 5 As shown, in the fourth view 503 of the third security element 5 at the first observation position, the fifth bright line 501 is located at the center of the fifth characteristic area 502. When the observation position is changed along different directions parallel to the surface of the third security element 5, the fifth bright line 501 moves in the corresponding fifth characteristic area 502 along different directions away from the center position. Compared with the fourth view 503 of the first observation position, the observation position of the fifth view 504 is changed to the lower right, that is, the third security element 5 is tilted to the upper left, and the fifth bright line 501 moves to the upper right; the observation position of the sixth view 505 is changed to the lower left, that is, the third security element 5 is tilted 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, and the bright line will move when the observation position is changed along these two directions. Therefore, the direction of movement of the bright line is perpendicular to the direction of inclination of the optical element, forming an unconventional visual effect.

[0081] As a convertible implementation method, it can also be, Figure 6 As shown, the first direction 1 and the second direction 2 are both at a specific angle, such as an acute angle, to the tangent direction of the bright line. When the anti-counterfeiting element is tilted, the moving direction of the bright line and the tilting direction of the anti-counterfeiting element are also at a specific angle. Figure 6 Taking the fourth anti-counterfeiting element 6 in the figure as an example, the sixth bright line 601 corresponds to the sixth characteristic area 602, and the curved surface structures at different positions in the sixth characteristic area 602 have their own specific optical coordinates, and the optical coordinates include a first direction 1 and a second direction 2. The optical coordinates of the curved surface structures at different positions correspond one-to-one to line segments with different curvatures on the adjacent sixth bright line 601, wherein the first direction 1 and the second direction 2 respectively form specific angles with the tangent direction of the adjacent sixth bright line 601.

[0082] like Figure 1 As shown, the bright lines in this embodiment include straight lines and curved lines. Figure 1 The first anti-counterfeiting element 3 in the figure 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 a first characteristic area 304, the second bright line 302 corresponds to a second characteristic area 305, and the third bright line 303 corresponds to a third characteristic area 306. The combination of bright lines is not limited thereto. In fact, in other embodiments, these bright lines can have other shapes, can form dynamic patterns by themselves, and can form other dynamic patterns with other bright lines or even bright lines of other effects, and no excessive restrictions are made here.

[0083] According to the needs of dynamic pattern design, the bright line can be a straight line, such as the second bright line 302; it can also be a curve, such as the first bright line 301; it can also 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; there can be a fold point on the bright line, such as the third bright line 303; the bright lines can be disconnected from head to tail, such as the second bright line 302 and the third bright line 303; they can also be connected from head to tail, such as the second bright line 302; the bright lines can intersect, such as the first bright line 301 and the second bright line 302 intersect, the first characteristic area 304 of the first bright line 301 and the second characteristic area 305 of the second bright line 302 also intersect, and in the overlapping area, the curved surface structure corresponding to the first bright line 301 and the curved surface structure corresponding to the second bright line 302 are mixed.

[0084] For those with special needs for dynamic pattern design, bright lines can also form a variety of dynamic patterns through various shapes and combinations, such as numbers, letters, Chinese characters, simple drawings, geometric figures, etc.

[0085] In one embodiment, the dynamic pattern has two bright lines moving in opposite directions, which will form a stronger dynamic contrast effect.

[0086] 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 difference in slopes on a section line drawn on a plane parallel to the first direction 1 and the height direction 7 of the curved structure, or on a plane parallel to the second direction 2 and the height direction 7 of the curved structure. The slope difference of the section line refers to the difference in slopes between the two points on the section line where the slopes differ the most. The greater the slope difference, the greater the degree of curvature.

[0087] The curved surface structure has a preset inclination direction along the second direction 2, and the inclination degree 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. Specifically, the inclination degree 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. Further, the inclination degree 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. Here, the inclination degree of the curved surface structure along the second direction 2 refers to the inclination degree of the section line of the curved surface structure on the plane parallel to the second direction 2 and the height direction 7, which can be represented by the average slope of the section line of the curved surface structure on the plane parallel to the second direction 2 and the height direction 7.

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

[0089] In order to improve the viewing angle of the emitted light, the difference in slope of at least two locations of the curved structure along the first direction 1 is greater than 0.1. As a changeable implementation, the difference in slope of at least two locations of the curved structure along the first direction 1 may be between 0.05 and 0.1.

[0090] In order to improve the clarity of the bright line, the slope difference of at least part of the curved surface structure along the second direction 2 is less than 0.05. Specifically, the curved surface structure is roughly straight along the second direction 2. That is, the section of the curved surface structure on the plane parallel to the second direction 2 and the height direction 7 is straight. The straightness here is not absolute straightness in the mathematical sense. The section line is allowed to have small fluctuations relative to the straight line. For optical reflection or refraction, the fluctuation amount less than a quarter of the wavelength optical path difference can be ignored and considered to be straight. As a convertible embodiment, it is also possible that the slope difference of the curved surface structure along the second direction 2 is between 0.05 and 0.2.

[0091] In one embodiment, the slope difference of at least part of the curved surface structure along the first direction 1 is greater than 2 times the slope difference of the curved surface structure along the second direction 2. Specifically, the slope difference of at least part of the curved surface structure along the first direction 1 is greater than 5 times the slope difference of the curved surface structure along the second direction 2. Since the curved surface structure needs to satisfy the requirement that the degree of curvature along the first direction 1 is greater than the degree of curvature of the curved surface structure along the second direction 2, in order to distinguish the bright line, increasing the ratio of the slope difference of the curved surface structure in the first direction 1 to the slope difference of the curved surface structure in the second direction 2 is helpful to improve the clarity of the bright line. As a convertible implementation, it may also be that the slope difference of at least part of the curved surface structure along the first direction 1 is greater than 3 times, or 4 times, the slope difference of the curved surface structure along the second direction 2.

[0092] In one embodiment, the slope difference of at least part of the curved surface structure along the first direction 1 is between 1.4 times and 2.8 times the maximum average slope of the curved surface structure along the second direction 2. By setting the slope difference of the curved surface structure along the first direction 1 to between 1.4 times and 2.8 times the maximum average slope of the curved surface structure along the second direction 2, the consistency of the observable angle can be achieved. Since the maximum values ​​of the slopes of the curved surface structure in the first direction 1 and the second direction 2 should be approximately the same, the slope distribution of a single curved surface structure in the first direction 1 is approximately symmetrical, so the maximum value of the slope of a single curved surface structure in the first direction 1 is half of the slope difference of the single curved surface structure; different curved surface structures have different slopes in the second direction 2, and the maximum value of the slope in the second direction 2 is the slope of the curved surface structure with the largest average slope in the second direction 2. Therefore, in the most ideal case, the slope difference of the curved surface structure in the first direction 1 is twice the maximum average slope of the curved surface in the second direction 2. As a convertible implementation, the slope difference of the curved surface along the first direction 1 may be 1.4 times, 1.5 times, 2.5 times, or 2.8 times the maximum average slope of the curved surface structure along the second direction 2.

[0093] In one embodiment, the slope difference of at least part of the curved surface structure along the first direction 1 does not change with the distance between the curved surface structure and the bright line at the center. By making the slope difference of the curved surface structure along the first direction 1 not change with the distance between the curved surface structure and the bright line at the center, the curvature of different curved surface structures in the first direction 1 can be made similar, thereby ensuring the consistency of the observable angle. As a convertible implementation, it is also possible that the slope difference of at least part of the curved surface structure along the first direction 1 decreases as the distance between the curved surface structure and the bright line at the center increases. Since the average slope of the curved surface structure along the second direction 2 increases as the distance between the curved surface structure and the bright line at the center increases, in order to achieve consistency of the observation angle, the slope difference of the curved surface structure along the first direction 1 can be appropriately reduced so that the total slope of the curved surface structure does not exceed the maximum expectation.

[0094] like Figure 7 As shown, the cross section of a single curved surface structure along the first direction 1 is in the shape of a convexity. It should be noted that the schematic diagram is only for illustration and does not represent actual parameters such as size, proportion and quantity. For example, in practice, the size of a curved surface structure is at least one order of magnitude smaller than the size of the feature area. There will be a considerable number of curved surface structures in a feature area, but only a small number of curved surface structures are used in the schematic diagram for illustration; for example, the boundary of the curved surface structure in the schematic diagram is parallel to the first direction 1 or the second direction 2. In practice, the boundary of the curved surface structure may not be parallel to the first direction 1 and the second direction 2, or may be a polygon or have a curved boundary. The first curved surface structure 8, the second curved surface structure 9, and the third curved surface structure 10 are examples of only one convexity in the first direction 1. The first curved surface structure 8 is located near the bright line at the center position, and it is basically not tilted or tilted very little in the second direction 2. The third curved surface structure 10 is located at the edge of the feature area, and its tilt in the second direction 2 is the largest. The tilt here can be represented by a tilt angle or slope. From the first curved surface structure 8 to the third curved surface structure 10, that is, as the distance from the curved surface structure to the central bright line increases, the degree of inclination of the curved surface structure in the second direction 2 increases. As a changeable implementation, the cross section of the curved surface structure along the first direction 1 may be concave.

[0095] As a changeable implementation, it is also possible that the cross section of at least part of the curved surface structure along the first direction 1 includes both convex and concave shapes, that is, is wavy. Figure 8 It is a schematic diagram of this embodiment. It should be noted that the schematic diagram is only used for illustration and does not represent actual parameters such as size, proportion and quantity. For example, in practice, the size of a curved surface structure is at least one order of magnitude smaller than the size of the feature area, and there will be a considerable number of curved surface structures in a feature area, but only a small number of curved surface structures are used in the schematic diagram; for example, the boundary of the curved surface structure in the schematic diagram is parallel to the first direction 1 or the second direction 2, and in practice, the boundary of the curved surface structure may not be parallel to the first direction 1 and the second direction 2, or may be a polygon or have a curved boundary. The fourth curved surface structure 11, the fifth curved surface structure 12, and the sixth curved surface structure 13 are examples of wavy cross-sections along the first direction 1. The fourth curved surface structure 11 is located near the bright line at the center position, and it is basically not tilted or has a very small tilt along the second direction 2. The sixth curved surface structure 13 is located at the edge of the feature area, and its tilt along the second direction 2 is the largest. From the fourth curved surface structure 11 to the sixth curved surface structure 13, that is, as the distance to the bright line at the center position increases, the tilt of the curved 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 a sudden change in slope at the junction of the adjacent curved surface structures. Figure 8The slope of the junction between the curved surface structures adjacent to each other along the first direction 1 is continuous. Such a setting is beneficial to improving the utilization rate of light by the anti-counterfeiting element.

[0097] Among them, the distance between the highest point and the lowest point of the cross section of the curved structure along the first direction 1 is greater than 3μm, and the extension length of the curved structure along the second direction 2 is between 3μm and 50μm. Since the cross section of the curved structure along the first direction 1 is set to be convex, concave or wavy, by limiting the distance between the highest point and the lowest point of the cross section of the curved structure along the first direction 1 to be greater than 3μm, the distance between the highest point and the lowest point will not be too small, preventing the distance from being too small to produce unexpected diffraction effects. By limiting the length of the curved structure along the second direction 2, it is possible to prevent the curved structure from being too long along the second direction 2. The longer the curved structure, the higher the production process. Of course, when setting it specifically, the distance between the highest point and the lowest point of the cross section of the curved structure 6 along the first direction 1 can be set to 3.5μm, 4μm, 10μm, 40μm, etc., and no excessive restrictions are made here.

[0098] In one embodiment, at least some of the borders 16 of the adjacent curved structures are arranged in a curved manner, which is conducive to reducing the height fluctuation on the borders 16, reducing the total height of the curved structure, and then reducing the difficulty of production. Specifically, some of the borders 16 of the curved structure are arranged according to the contour lines of the curved structure. Since the borders 16 of the curved structure are arranged in a curved manner, the curved structure is arranged according to the contour lines of the curved structure at the borders 16, so that the edges of the curved structure at the borders 16 are of the same height, and this arrangement can avoid the height fluctuation at the edges of the curved structure.

[0099] Fig. 9 This is a schematic diagram. In the characteristic area of ​​the anti-counterfeiting element, there is a boundary 16 between the seventh curved surface structure 14 and the eighth curved surface structure 15. The boundary 16 is set according to the contour line of the seventh curved surface structure 14, that is, the edge of the seventh curved surface structure 14 on the boundary 16 is of the same height. Compared with setting the boundary 16 in the shape of a straight line, this setting avoids the height floating of the edge of the curved surface structure. It should be noted that Fig. 9 The small squares in the figure are only used to help you see that the boundaries 16 of the adjacent curved surface structures are arranged along the contour lines, and have no other practical meaning.

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

[0101] In one embodiment, the curved surface structure is covered with a metal layer and a dielectric layer, which can enhance the reflective effect of the curved surface structure. Specifically, the curved surface structure can be at least partially covered with a metal-dielectric-metal three-layer structure, and the metal-dielectric-metal three-layer structure can achieve an appearance that changes color with the observation angle, such as an aluminum-silicon dioxide-chromium three-layer structure, or a dielectric-metal-dielectric three-layer structure, a multi-layer dielectric structure, etc. can also achieve similar appearance effects. As a convertible implementation, it is also possible that the curved surface structure is only covered with a metal layer, or only covered with a dielectric layer. As a convertible implementation, it is also possible that the curved surface structure is only partially covered with a metal layer, or a dielectric layer, or both a metal layer and a dielectric layer.

[0102] In one embodiment, at least part of the curved structure is provided with a secondary microstructure, such as a one-dimensional or two-dimensional grating with a period less than 450 nanometers, etc. By providing the secondary microstructure, the color of the reflected light can be modulated to achieve an appearance effect of at least two colors at a fixed observation angle.

[0103] In one embodiment, the difference in refractive index of the materials on both sides of the curved surface structure is greater than 0.1. Since the difference in refractive index is required on both sides of the curved surface structure to achieve the refraction effect of light, the materials on both sides of the curved surface structure here may refer to one side of the curved surface structure exposed to the air, generally the interface between the air and the resin material has a large difference in refractive index, or the refractive index of the resin materials on both sides of the curved surface structure is different. By limiting the difference in refractive index of the materials on both sides of the curved surface structure to be greater than 0.1, the refraction effect of the outgoing light can be improved.

[0104] In order to extend the life of the anti-counterfeiting element, a protective adhesive or a composite protective film may also be coated on the curved surface structure.

[0105] In one embodiment, at least part of the characteristic area includes at least part of the dissipative structure, and the slope of the dissipative structure is greater than the maximum slope of the curved surface structure in the anti-counterfeiting element. The dissipative structure here can be a curved surface structure or a straight surface structure, as long as its slope is set to be greater than the maximum slope of other curved surface structures in the anti-counterfeiting element, and there are no excessive restrictions here. In order to dissipate the excess light after the bright line is formed, by setting a dissipative structure with a larger slope, part of the excess light can be dissipated to the non-observation direction, thereby enhancing the uniformity of the light intensity on the bright line.

[0106] The anti-counterfeiting element disclosed in this embodiment has the advantages of high resolution and uniform distribution of the angle of the emitted light. 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, which can not only achieve a higher resolution dynamic effect, but also achieve a more uniform distribution of the angle of the emitted light, and achieve a more refined and stable appearance pattern.

[0107] The anti-counterfeiting element disclosed in this embodiment is more difficult to forge, and the curved surface structure with customized morphology has a higher degree of freedom, requiring more parameters to describe a single curved surface structure. These parameters are difficult to measure and even more difficult to be copied and forged by counterfeiters.

[0108] According to an embodiment of the present invention, on the other hand, there is provided an article with an anti-counterfeiting element, comprising: the anti-counterfeiting element mentioned above.

[0109] The article with anti-counterfeiting element in the present embodiment is a banknote. As a convertible embodiment, it can also be that the article with anti-counterfeiting element is anti-counterfeiting paper, or an identity card 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, the first part is arranged inside the banknote, and the second part is arranged outside the banknote. As a convertible embodiment, the anti-counterfeiting element can also be hot-stamped on the surface of the banknote by pre-coating hot melt adhesive, or the anti-counterfeiting element is pasted on the surface of the banknote.

[0111] The anti-counterfeiting element can specifically be a security thread, a sealing tape, a security tape, a security strip, a patch, a label, etc., so as to be applied to items such as security paper and valuable documents.

[0112] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. An anti-counterfeiting element, characterized in that: include: A dynamic pattern, wherein the dynamic pattern comprises at least one bright line, and the dynamic pattern has an appearance that changes with the observation angle. When the dynamic pattern is observed in a first observation direction, the bright line appears at the center of the dynamic pattern. When the anti-counterfeiting element is tilted in different directions, the bright line moves away from the center, and the area where the bright line moves is the characteristic area. The characteristic region comprises a plurality of curved surface structures, each of the curved surface structures having a plurality of optical coordinates parallel to a surface of the characteristic region, each of the optical coordinates comprising a first direction (1) and a second direction (2), each of the optical coordinates corresponding one-to-one to a line segment having a different curvature on the bright line; the curved surface structure is arranged in a curved manner along the first direction (1), and the degree of curvature of the curved surface structure along the second direction (2) is smaller than the degree of 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 arranged at a preset angle with respect 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; Alternatively, 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 surface structure has a preset inclination direction along the second direction (2), and the degree of inclination 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.

5. The anti-counterfeiting element according to claim 4, characterized in that: The degree of inclination 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.

6. The anti-counterfeiting element according to claim 5, characterized in that: The degree of inclination 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.

7. The anti-counterfeiting element according to any one of claims 1 to 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 a slope difference, wherein the slope difference refers to a maximum value of the difference in slopes on a section drawn on a plane parallel to the first direction (1) and the height direction (7) of the curved structure, or a section drawn on a 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: The slope difference of at least part of the curved surface structure along the first direction (1) is greater than 0.

05.

9. The anti-counterfeiting element according to claim 8, characterized in that: The slope difference of at least part of the curved surface structure along the first direction (1) is greater than 0.

1.

10. The anti-counterfeiting element according to claim 7, characterized in that: The slope difference of at least part of the curved surface structure along the second direction (2) is less than 0.

05.

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

12. The anti-counterfeiting element according to claim 7, characterized in that: The slope difference of at least part 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).

13. The anti-counterfeiting element according to claim 12, characterized in that: The slope difference of at least part of the curved surface structure along the first direction (1) is greater than 5 times the slope difference of the curved surface structure 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 curved surface structure along the first direction (1) is between 1.4 and 2.8 times the maximum average slope of the curved surface structure along the second direction (2).

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

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

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

18. The anti-counterfeiting element according to claim 17, characterized in that: The distance between the highest point and the lowest point 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 shape.

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

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

22. The anti-counterfeiting element according to any one of claims 1 to 6, characterized in that: The bright line includes a straight line and / or a curved line.

23. The anti-counterfeiting element according to any one of claims 1 to 6, characterized in that: The extension 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 to 6, characterized in that: The curved surface structure is at least partially covered with a metal layer; And / or, the curved surface structure is at least partially covered with a dielectric layer; and / or, the curved surface structure is at least partially provided with a secondary microstructure; And / or, the difference in refractive index between 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 to 6, characterized in that: At least part of the characteristic area at least partially includes a dissipative structure, and the slope of the dissipative structure is greater than the maximum slope of the curved surface structure in the anti-counterfeiting element.

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

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

28. The article with the security element according to claim 27, characterized in that: The anti-counterfeiting element comprises a first part and a second part, wherein the first part is arranged inside the article having the anti-counterfeiting element, and the second part is arranged outside the article having the anti-counterfeiting element; Alternatively, the anti-counterfeiting element is attached to the surface of the article having the anti-counterfeiting element.

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