Optical anti-counterfeiting element and optical anti-counterfeiting product

Abstract

The invention provides an optical anti-counterfeiting element and an optical anti-counterfeiting product. The optical anti-counterfeiting element comprises a base material; the microstructure layer is located on the surface of at least one side of the base material, at least one characteristic straight line is arranged in the plane where the microstructure layer is located, the microstructure layer comprises a plurality of reflection structures in the extending direction of the characteristic straight line, the side, away from the base material, of each reflection structure is provided with a reflection face, and the plane angle of a dihedral angle formed by the reflection face and the surface of the base material is an inclination angle; wherein the inclination angles of all the reflection structures in the direction of the characteristic straight line at least comprise one change period, in one change period, the change of all the inclination angles is formed by superposing main change and secondary change, and when the optical anti-fake element is rotated along a rotating shaft in the plane where the optical anti-fake element is located, the change of all the inclination angles is changed. The optical security element exhibits a global dynamic feature and a localized dynamic feature due to the primary and secondary variations. The problem that dynamic characteristics of an optical anti-counterfeiting element in the prior art are not easy to recognize is solved.

Description

Technical Field

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

[0002] Public anti-counterfeiting features are aimed at the widest range of users and need to have easily identifiable features so that the general public can distinguish the authenticity in a very short time. The printed images and texts obtained by traditional printing processes generally have the same properties when observed from all angles due to the diffuse reflection properties of ink, and the reflected light intensity and spectrum generally remain unchanged. This property is easy to identify, but it changes less, cannot bring unique effects, and is easily copied and imitated by criminals. Optical anti-counterfeiting is a method that achieves unique features that are different from the stability and planarity of traditional printing through a variety of means such as special coatings, micro-nano structures, and frame sampling. Through the combined application of the above technologies, the metal features of directional reflection and the three-dimensional features floating / sinking on the plane of the optical anti-counterfeiting element can be achieved. At the same time, due to the directional nature of the micro-nano structure and the coating, the emission direction of the light can be modulated to a specific direction, which can also produce interactive features, that is, when the public moves (tilts forward and backward, tilts left and right, and rotates left and right) the optical anti-counterfeiting element, the light at different positions / patterns is observed, and the images at each position are connected to form a dynamic feature. This dynamic feature can effectively guide the observer's attention, bringing the public's eyes to the location of the optical anti-counterfeiting element, arousing the observer's interest, and further observing the dynamic features to distinguish the authenticity.

[0003] When the dynamic feature is determined by the micro-nano structure, a certain range of dynamic effects can be achieved by selecting the type of microstructure and its parameters. For example, the traditional holographic grating can form a dynamic feature by changing its period, angle and other parameters and arranging the grating in sequence according to a specific rule. However, when the distance the dynamic feature moves in the optical anti-counterfeiting element is too long, the above microstructure will be "diluted" to the long distance, which will result in the microstructure having the same parameters in a longer area, which will cause the area to be seen by the observer at the same time, forming a wide bright spot, blurring the dynamic feature and weakening the visual impact of the dynamic feature on the observer.

[0004] In other words, the optical anti-counterfeiting elements in the prior art have the problem that dynamic features are difficult to identify. Summary of the invention

[0005] The main purpose of the present invention is to provide an optical anti-counterfeiting element and an optical anti-counterfeiting product to solve the problem in the prior art that the dynamic features of the optical anti-counterfeiting element are difficult to identify.

[0006] To achieve the above object, according to one aspect of the present invention, an optical anti-counterfeiting element is provided, comprising: a substrate; a microstructure layer located on at least one surface of the substrate, having at least one characteristic straight line in the plane of the microstructure layer, along the extending direction of the characteristic straight line, the microstructure layer includes a plurality of reflection structures, the side of the reflection structure away from the substrate has a reflection surface, and the plane angle of the dihedral angle formed by the reflection surface and the surface of the substrate is the inclination angle; wherein, along the direction of the characteristic straight line, the inclination angles of all the reflection structures at least include one change cycle, within one change cycle, the change of all the inclination angles is composed of a main change and a secondary change superimposed, when rotating the optical anti-counterfeiting element along a rotation axis in the plane where the optical anti-counterfeiting element is located, the optical anti-counterfeiting element presents a global dynamic feature and a local dynamic feature due to the main change and the secondary change.

[0007] Further, within one change cycle, the main change at least includes that the inclination angle of the reflection structure at the beginning of the change cycle is the largest, and the inclination angle of the reflection structure at the end of the change cycle is the smallest.

[0008] Further, within one change cycle, the main change at least includes that the inclination angle of the reflection structure at the beginning of the change cycle is the smallest, and the inclination angle of the reflection structure at the end of the change cycle is the largest.

[0009] Further, within one change cycle, the main change at least includes that from the beginning to the end of the change cycle, the inclination angle of the reflection structure changes first decreasing and then increasing.

[0010] Further, within one change cycle, the secondary change at least includes that the inclination angles of at least a part of all the reflection structures have at least one alternating change process of increasing and decreasing.

[0011] Further, the main change and the secondary change have standard change design values, and the inclination angles randomly change within the range of 80%-120% of the standard change design values.

[0012] Further, the inclination angles randomly change within the range of 90%-110% of the standard change design values.

[0013] Further, the angle formed by the rotation of the reflection structure along the normal line perpendicular to the surface of the substrate is the rotation angle.

[0014] Further, at least a part of all the reflection structures of the microstructure layer form an adjustment structure, and the rotation angles of the reflection structures in the adjustment structure change randomly or pseudo-randomly.

[0015] Further, the number of reflection structures in the adjustment structure is n and is divided into m groups, the rotation angles of the reflection structures in the same group are the same, the rotation angles of the reflection structures in different groups change randomly or pseudo-randomly, where m < n and the number of reflection structures in each group is not less than 1.

[0016] Furthermore, the rotation axes and the characteristic straight lines are arranged in one-to-one correspondence, and the correspondingly arranged rotation axes and characteristic straight lines are arranged at an angle.

[0017] Furthermore, the angle between the corresponding rotation axis and the characteristic straight line is α, the global dynamic feature includes a rolling feature, the angle between the moving direction of the rolling feature and the rotation direction of the optical anti-counterfeiting element is β, and the sum of α and β is 90°.

[0018] Furthermore, the optical anti-counterfeiting element also includes a coating, which is located on a surface of the microstructure layer that is away from the substrate, and is used to enhance reflection or transmission effects.

[0019] Furthermore, the coating is a single-layer coating.

[0020] Furthermore, the single-layer coating includes one of a single-layer metal coating or a single-layer dielectric coating.

[0021] Furthermore, the coating is a multi-layer coating.

[0022] Furthermore, the multi-layer coating includes one of coatings formed by alternately stacking a multi-layer dielectric coating, a metal coating and a dielectric coating.

[0023] Furthermore, the multi-layer coating is a Fabry-Perot resonant cavity structure composed of a metal coating, a dielectric coating and a metal coating.

[0024] Furthermore, the characteristic size of the reflective structure is greater than or equal to 1 μm and less than or equal to 500 μm.

[0025] Furthermore, the characteristic size of the reflective structure is greater than or equal to 2 μm and less than or equal to 100 μm.

[0026] Furthermore, a surface of the reflective structure on one side away from the substrate is a plane, and the plane forms a reflective surface.

[0027] Furthermore, the surface of the reflective structure away from the substrate is a curved surface, and the average value of the dihedral angles formed by the tangent plane at each point on the curved surface and the surface of the substrate represents the dihedral angles formed by the reflective surface and the surface of the substrate.

[0028] According to another aspect of the present invention, there is provided an optical anti-counterfeiting product, comprising the above-mentioned optical anti-counterfeiting element.

[0029] Applying the technical solution of the present invention, the optical anti-counterfeiting element includes a substrate and a microstructure layer, the microstructure layer is located on at least one side surface of the substrate, and the plane where the microstructure layer is located has at least one characteristic straight line. The microstructure layer includes multiple reflective structures along the extension direction of the characteristic straight line, and the reflective structure has a reflective surface on the side away from the substrate, and the plane angle of the dihedral angle formed by the reflective surface and the surface of the substrate is the inclination angle θ; wherein the inclination angle θ of all reflective structures along the direction of the characteristic straight line includes at least one variation cycle, and within one variation cycle, the variation of all inclination angles θ is the superposition of primary changes and secondary changes, and when the optical anti-counterfeiting element is rotated along a rotation axis within the plane where the optical anti-counterfeiting element is located, the optical anti-counterfeiting element presents global dynamic characteristics and localized dynamic characteristics due to the primary changes and secondary changes.

[0030] By arranging multiple reflective structures with reflective surfaces along the characteristic straight line, the reflective surface can be used to reflect light into the human eye, so that the user can observe the reflective surface at that position, and the inclination angle θ of the reflective surface changes according to a specific rule, which can bring many unique optical effects. At the same time, on the characteristic straight line, the inclination angle θ of each reflective surface has a change cycle, and the change of the inclination angle θ of each reflective surface within the change cycle is divided into a primary change and a secondary change, so that when the optical anti-counterfeiting element is rotated along the rotation axis, the user can observe the global dynamic features and the localized dynamic features. The dynamic features are more complex and delicate, which ensures the anti-counterfeiting effect while facilitating user identification. The dynamic features are clearly visible during the entire process of the user rotating the optical anti-counterfeiting element. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0032] Figure 1 A schematic diagram showing the application of the optical anti-counterfeiting element according to the first embodiment of the present invention is shown;

[0033] Figure 2 Shows Figure 1 An enlarged schematic diagram of a part of the area;

[0034] Figure 3 Shows Figure 1 A cross-sectional view of the optical anti-counterfeiting element along a characteristic straight line;

[0035] Figure 4 Shows Figure 1 Schematic diagram of the inclination distribution of the reflecting surface in FIG.

[0036] Figure 5 Shows Figure 4 Schematic diagram of the change of the inclination angle of the reflecting surface along the characteristic straight line;

[0037] Figure 6 Shows Figure 1 Schematic diagram of dynamic characteristics of the optical anti-counterfeiting element rotating back and forth around the rotation axis at different angles;

[0038] Figure 7 A schematic diagram showing reflective surfaces with different inclination angles but the same rotation angle in an optical anti-counterfeiting element according to a second embodiment of the present invention;

[0039] Figure 8 Shows Figure 7 Schematic diagram after the corners in the image are randomly changed;

[0040] Fig. 9 A schematic diagram showing a reflective surface having the same inclination angle and rotation angle in an optical anti-counterfeiting element according to a second embodiment of the present invention;

[0041] Fig.10 Shows Fig. 9 Schematic diagram after the corners in the image are randomly changed;

[0042] Fig.11 A schematic diagram showing the distribution of a group of rotation axes and characteristic straight lines of the optical anti-counterfeiting element according to the third embodiment of the present invention is shown;

[0043] Fig.12 Shows Fig.11 Schematic diagram of dynamic characteristics of the optical anti-counterfeiting element rotating back and forth around the rotation axis at different angles;

[0044] Fig.13 A schematic diagram showing the distribution of a group of rotation axes and characteristic straight lines of the optical anti-counterfeiting element according to the fourth embodiment of the present invention is shown;

[0045] Fig.14 Shows Fig.13 Schematic diagram of the change of the inclination angle of the reflecting surface along the characteristic straight line;

[0046] Fig.15 Shows Fig.13 Schematic diagram of dynamic characteristics of the optical anti-counterfeiting element rotating back and forth around the rotation axis at different angles;

[0047] Fig.16 A schematic diagram showing the relative positions of the reflective structure and the coating layer of the fifth embodiment of the present invention is shown;

[0048] Fig.17 Shows Fig.16 Schematic diagram of the coating composition.

[0049] The above drawings include the following reference numerals:

[0050] 10. substrate; 20. microstructure layer; 21. reflective structure; 22. reflective surface; 11. partial area; 101. upper position; 102. middle position; 103. lower position; 12. partial area; 121. secondary position; 1011. first change area; 1012. second change area; 1013. third change area; 103. lower position; 201. first area; 202. second area; 221. first reflective surface; 222. second reflective surface; 223. third reflective surface ; 224, fourth reflection surface; 225, first reflection group; 226, second reflection group; 227, third reflection group; 30, characteristic straight line; 40, rotation axis; 50, coating; 51, reflection layer; 52, dielectric layer; 53, absorption layer; 60, optical anti-counterfeiting element; 70, carrier; 80, illumination light source; 81, incident light; 82, reflected light of the first reflection surface; 83, reflected light of the third reflection surface; 84, reflected light of the second reflection surface; 85, reflected light of the fourth reflection surface; 90, observer. DETAILED DESCRIPTION

[0051] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0053] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0054] In order to solve the problem in the prior art that dynamic features of optical anti-counterfeiting elements are difficult to identify, the present invention provides an optical anti-counterfeiting element and an optical anti-counterfeiting product.

[0055] like Figures 1 to 17As shown, the optical anti-counterfeiting element includes a substrate 10 and a microstructure layer 20, the microstructure layer 20 is located on at least one side surface of the substrate 10, and there is at least one characteristic straight line 30 in the plane where the microstructure layer 20 is located. The microstructure layer 20 includes a plurality of reflective structures 21 along the extension direction of the characteristic straight line 30, and the reflective structure 21 has a reflective surface 22 on the side away from the substrate 10, and the plane angle of the dihedral angle formed by the reflective surface 22 and the surface of the substrate 10 is an inclination angle θ; wherein the inclination angle θ of all the reflective structures 21 along the direction of the characteristic straight line 30 includes at least one variation cycle, and within one variation cycle, the variation of all the inclination angles θ is a superposition of primary changes and secondary changes, and when the optical anti-counterfeiting element 60 is rotated along a rotation axis 40 in the plane where the optical anti-counterfeiting element 60 is located, the optical anti-counterfeiting element 60 presents global dynamic characteristics and localized dynamic characteristics due to the primary changes and secondary changes.

[0056] By arranging a plurality of reflective structures 21 having reflective surfaces 22 along the characteristic straight line 30, the reflective surface 22 can be used to reflect light into the human eye, so that the user can observe the reflective surface 22 at this position, and the inclination angle θ of the reflective surface 22 changes according to a specific rule, which can bring many unique optical effects. At the same time, on the characteristic straight line 30, the inclination angle θ of each reflective surface 22 has a change cycle, and the change of the inclination angle θ of each reflective surface 22 within the change cycle is divided into a main change and a secondary change, so that when the optical anti-counterfeiting element 60 is rotated along the rotation axis 40, the user can observe the global dynamic characteristics and the localized dynamic characteristics, and the dynamic characteristics are more complex and delicate, which ensures the anti-counterfeiting effect while facilitating user identification. The dynamic characteristics are clearly visible during the entire process of the user rotating the optical anti-counterfeiting element 60.

[0057] It should be noted that the secondary change is localized. In the extension direction along the characteristic straight line 30, the reflective structure 21 with secondary change characteristics only occupies a part, that is, the inclination angle θ of the reflective surface 22 of this part has the superposition of the main change and the secondary change. Under the superposition of the main change and the secondary change, the light reflected by the reflective surface 22 of this part of the reflective structure 21 presents a localized dynamic feature. "Superposition" means that the two are organically combined through calculation to form a new overall dynamic feature. In addition, since the secondary change is localized, that is, part of the main change process, it is definitely smaller than the main change in terms of occupied area. At the position of the reflective structure 21 that only has the main change but no secondary change, the dynamic feature exhibited is part of the global dynamic feature. The present application can realize the superposition of more complex and detailed localized dynamics on the basis of the original global long-distance dynamics. Its global dynamic features and localized dynamic features are not simply independently added, but influence each other to form a whole, so as to realize the effective realization of long-distance dynamics.

[0058] Optionally, in one change cycle, the main change at least includes that the inclination angle θ of the reflective structure 21 at the beginning of the change cycle is the largest, and the inclination angle θ of the reflective structure 21 at the end of the change cycle is the smallest. By decreasing the inclination angle θ of the reflective structure 21 in one change cycle, the user observes the anti-counterfeiting feature presented at the position with the largest inclination angle θ at the beginning of the change cycle, and gradually observes the anti-counterfeiting feature presented at the position with smaller and smaller inclination angle θ as the optical anti-counterfeiting element 60 is rotated. In the process of rotating the optical anti-counterfeiting element 60, the anti-counterfeiting feature changes continuously, thereby presenting a dynamic feature.

[0059] It should be noted that the main change of the inclination angle θ brings about a global dynamic feature, that is, in the process of rotating the optical anti-counterfeiting element 60 along a single direction, the global dynamic feature also changes in a single direction.

[0060] Of course, it can also be arranged that within a change cycle, the main change at least includes that the inclination angle θ of the reflective structure 21 located at the beginning of the change cycle is the smallest, and the inclination angle θ of the reflective structure 21 located at the end of the change cycle is the largest.

[0061] Of course, it can also be set that within a change cycle, the main change includes at least from the beginning to the end of the change cycle, the inclination angle θ of the reflective structure 21 first decreases and then increases, so that the change direction of the global dynamic feature is not a single direction, enriching the effect of the global dynamic feature.

[0062] Specifically, within one change cycle, the secondary change at least includes that the inclination angle θ of at least a part of all the reflective structures 21 has at least one alternating change process of increasing and decreasing. By setting the change rule of the inclination angle θ of a part of the secondary change to alternating increase and decrease, under the condition that the original global dynamic feature remains unchanged, there is a non-single movement direction in one section, thereby presenting a localized dynamic feature. It should be noted that in order to ensure that the global dynamic feature is not affected by the localized dynamic feature, the inclination angle θ of the secondary change, no matter how it increases or decreases, will not be lower than the minimum value of the inclination angle θ with only the main change or higher than the maximum value of the inclination angle θ with only the main change.

[0063] For example, when the optical anti-counterfeiting element 60 is rotated in a single direction along the rotation axis 40, the global dynamic feature rolls in a certain direction, but in a certain section of the process, the localized dynamic feature displayed is inconsistent with the rolling direction of the global dynamic feature, and there is a reciprocating rolling direction of the dynamic feature, but the final rolling direction displayed is the rolling direction of the global dynamic feature.

[0064] Specifically, the primary change and the secondary change have standard change design values, and the inclination angle θ varies randomly within the range of 80%-120% of the standard change design value. When the surface of the optical anti-counterfeiting element 60 is too smooth and flat, the surface of the optical anti-counterfeiting element 60 will produce dazzling glare under the illumination of an external light source. If the position of the light source is not appropriate relative to the position where the user observes, the user may not be able to observe the dynamic pattern in the optical anti-counterfeiting element 60. Therefore, in order to further improve the public recognition of the optical anti-counterfeiting element 60 involved in the present invention, the reflective surface 22 can be randomized to a certain extent. Without changing the overall angle change law, that is, the standard change design value, the inclination angle θ of the reflective surface 22 can be changed randomly within the range of 80%-120% of the standard change design value to achieve a matte effect, reduce dazzling glare, and increase the observable angle.

[0065] Preferably, the inclination angle θ varies randomly within a range of 90%-110% of the standard variation design value.

[0066] Specifically, the angle at which the reflective structure 21 rotates along the normal to the surface perpendicular to the substrate 10 forms an angle φ. That is to say, the rotation of the reflective surface 22 along the normal to the surface perpendicular to the substrate 10 is represented by the angle φ. At the same time, due to different angles φ, the directions of light reflected by the reflective surface 22 will be different, so the change pattern of the angle φ will also affect the performance of the dynamic feature. In the optical anti-counterfeiting element 60 of the present application, the inclination angle θ determines the reflection direction of light at different positions. However, if the inclination angle θ of the reflective surface 22 meets the superposition of the above-mentioned primary changes and secondary changes, but the angle φ of the reflective surface 22 is in one direction, the observation method will be affected by the external light source, thereby affecting the observation effect and the expression effect of the optical anti-counterfeiting feature.

[0067] Specifically, the rotation axis 40 and the characteristic straight line 30 are arranged in a one-to-one correspondence, and the correspondingly arranged rotation axis 40 and the characteristic straight line 30 are arranged at an angle. It should be noted that the rotation axis 40 and the characteristic straight line 30 can be at any angle, and when the optical anti-counterfeiting element 60 is rotated along a certain rotation axis 40, the reflective surface 22 on the reflective structure 21 in the extension direction of the corresponding characteristic straight line 30 correspondingly presents a dynamic feature.

[0068] It should be noted that, in order to achieve a more easily observed dynamic effect and facilitate public identification, there can be multiple rotation axes 40, and correspondingly, there are also multiple characteristic straight lines 30 perpendicular to the optical anti-counterfeiting element 60. In this way, when the public tilts the optical anti-counterfeiting element 60, they do not need to look for the rotation axis 40 specifically, but can tilt the optical anti-counterfeiting element 60 at will to observe the dynamic characteristics.

[0069] Specifically, the angle between the corresponding rotation axis 40 and the characteristic straight line 30 is α, and the global dynamic feature includes a rolling feature. The angle between the movement direction of the rolling feature and the rotation direction of the optical anti-counterfeiting element 60 is β, and the sum of α and β is 90°. The angle α between the rotation axis 40 and the characteristic straight line 30 determines the angle β between the movement direction of the rolling feature and the rotation direction of the optical anti-counterfeiting element 60. For example, if the rotation axis 40 and the characteristic straight line 30 are perpendicular to each other, the movement direction of the rolling feature is the same as the rotation direction of the optical anti-counterfeiting element 60. For example, when the optical anti-counterfeiting element 60 is tilted forward and backward, the dynamic feature moves forward and backward. If the angle α between the rotation axis 40 and the characteristic straight line 30 is zero, the movement direction of the rolling feature is perpendicular to the rotation direction of the optical anti-counterfeiting element 60. For example, when the optical anti-counterfeiting element 60 is tilted forward and backward, the dynamic feature moves left and right.

[0070] It should be noted that the rotation direction of the optical anti-counterfeiting element 60 here refers to the direction perpendicular to the rotation axis of the optical anti-counterfeiting element 60 in the plane where the optical anti-counterfeiting element 60 is located.

[0071] Specifically, the optical anti-counterfeiting element 60 further includes a coating 50, which is located on the surface of the microstructure layer 20 on one side away from the substrate 10, and the coating 50 is used to enhance the reflection or transmission effect. By providing the coating 50 to enhance the optical effect, the recognizability of the dynamic feature can be improved, while the anti-counterfeiting effect is enriched and the difficulty of counterfeiting is increased. The coating 50 can be deposited on the surface of the substrate 10.

[0072] Optionally, the coating 50 is a single-layer coating, which is easy to process and shape, thereby reducing manufacturing costs.

[0073] Optionally, the single-layer coating includes one of a single-layer metal coating or a single-layer dielectric coating.

[0074] Of course, the coating 50 may also be a multi-layer coating to enrich the anti-counterfeiting effect and further increase the difficulty of counterfeiting.

[0075] Optionally, the multilayer coating includes one of the coatings formed by alternately stacking a multilayer dielectric coating, a metal coating and a dielectric coating. For example, when a metal reflective material is combined with a reflective grating (such as a wedge-type blazed grating with a period of 13 μm and a depth of 2 μm), the reflection efficiency is improved to form a bright reflection effect.

[0076] Optionally, the multilayer coating can be a stack of high and low refractive index materials, in which the refractive index of the high refractive index material n≥1.8, including but not limited to any material or combination of ZnS, TiN, TiO2, TiO, Ti2O3, Ti3O5, Ta2O5, Nb2O5, CeO2, Bi2O3, Cr2O3, Fe2O3; the refractive index of the low refractive index material n<1.8, including but not limited to any material or combination of SiO2, MgF2, Na3AlO6, Al2O3. The above-mentioned high and low refractive index materials are arranged in an overlapping manner up and down to form a film system structure of "high refractive index material / low refractive index material / high refractive index material / ... / high refractive index material". This structure can form selective reflection and transmission of specific spectral wavelengths, forming the first color when observed from the front, and the complementary color of the color when observed through light. When light is incident at an angle, the optical path that the light experiences when propagating in the high / low refractive index material stack is different from the optical path when it is incident vertically, forming a second color, thereby creating a color change effect.

[0077] Optionally, when the above-mentioned stacked structure of "high refractive material / low refractive index material / high refractive index material / ... / high refractive index material" is superimposed with a one-dimensional sub-wavelength grating (for example, its period is 350nm and its depth is 110nm), a third color different from the stacked structure can be formed.

[0078] Preferably, the multilayer coating is a Fabry-Perot resonant cavity structure composed of a metal coating, a dielectric coating, and a metal coating. The Fabry-Perot resonant cavity structure is a wavelength selection structure with higher reflection efficiency, which is a film structure of "absorption layer / dielectric layer / reflection layer". The absorption layer is a metal coating layer made of metal material with a relatively thin thickness. When light passes through this layer, about half of the light is reflected and the other half is transmitted, so the absorption layer can be called a "semi-reflective and semi-transparent film", including but not limited to chromium, nickel, copper, cobalt, titanium, vanadium, tungsten, tin, silicon, germanium and combinations thereof, and its thickness can be 2nm to 30nm. The dielectric layer is a dielectric coating layer, half of which is a metal compound. The dielectric layer material can be a low-refractive-index dielectric material with a refractive index less than 1.8, including but not limited to silicon dioxide, magnesium fluoride, cryolite, aluminum oxide and combinations thereof, and the thickness can be 100 to 1000nm; the dielectric material can also be a high-refractive-index material with a refractive index greater than 1.8, including but not limited to any material or combination of ZnS, TiN, TiO2, TiO, Ti2O3, Ti3O5, Ta2O5, Nb2O5, CeO2, Bi2O3, Cr2O3, and Fe2O3. The reflective layer is a metal coating layer, which is generally a metal material with high reflectivity, or an alloy thereof, including but not limited to any material or combination of aluminum, silver, tin, nickel, chromium, platinum, copper, gold, and silicon, with a thickness greater than or equal to 10nm.

[0079] In the Fabry-Perot resonant cavity structure, the absorption layer acts as a beam splitter, reflecting the general light (called the first light beam) and transmitting half of the light. After the transmitted light passes through the dielectric layer, it is reflected by the reflection layer and then emitted through the absorption layer (called the second light beam). The first light beam and the second light beam interact with each other to produce interference, forming a selective enhancement of a specific wavelength, so that the color can be observed. When the light changes the incident direction, the optical path of the light beam in the dielectric layer changes. If the dielectric material is a high refractive index material, the color does not change or the change is not obvious. If the dielectric material is a low refractive index material, the color changes significantly, which has the so-called light-changing effect. For example, the Fabry-Perot resonant cavity structure can be metal chromium / silicon dioxide / metal aluminum or metal aluminum / aluminum dioxide / metal aluminum. When the observation angle is changed, the color of the Fabry-Perot resonant cavity structure can change.

[0080] It should be noted that, no matter the coating 50 is a single-layer coating or a multi-layer coating, the metal coating contained in the coating 50 is preferably a metal reflective coating, which is usually made of a metal material with high reflectivity or its corresponding alloy material, which can be a full-spectrum reflective material and a corresponding alloy, such as aluminum, silver, tin, nickel, chromium, platinum, or a reflective material with a specific color and a corresponding alloy material, such as copper, gold and other materials, which can produce a fixed color while providing a high reflectivity. The function of the metal reflective coating is mainly to improve the diffraction or reflection efficiency, and the metal reflective coating itself does not have the effect of color change.

[0081] It should be noted that, no matter the coating 50 is a single-layer coating or a multi-layer coating, the dielectric coating contained in the coating 50 may be a metal compound, and the metal compound may be a metal oxide, such as titanium dioxide, silicon dioxide, zirconium dioxide, etc.; it may also be a metal sulfide, such as zinc sulfide; or it may be other metal compounds. The dielectric coating may also be an optical dielectric material, such as silicon dioxide, etc.

[0082] Specifically, the characteristic size of the reflective structure 21 is greater than or equal to 1μm and less than or equal to 500μm. It should be noted that the characteristic size measures the size of the projection of the reflective structure 21 on the plane where the optical anti-counterfeiting element 60 is located, and is greater than or equal to 1μm and less than or equal to 500μm in two orthogonal directions. Generally speaking, the two orthogonal directions refer to the width or period of the reflective structure 21. In one dimensional direction, the characteristic size of the reflective structure 21 is 1μm to 500μm, and the other dimension orthogonal to the above dimension can be a macroscopic size comparable to the optical anti-counterfeiting element 60, or it can be 1μm to 500μm.

[0083] Preferably, the characteristic size of the reflective structure 21 is greater than or equal to 2 μm and less than or equal to 100 μm.

[0084] Optionally, the surface of the reflective structure 21 on one side away from the substrate 10 is a plane, and the plane forms a reflective surface. The plane can achieve higher reflection efficiency and realize directional reflection of incident light. The tiny reflective surface 22 can be made by laser etching, electron beam etching, etc.

[0085] Of course, the surface of the side of the reflective structure 21 away from the substrate 10 can also be selected as a curved surface, and the average of the plane angles of the dihedral angles formed by the tangent plane at each point on the curved surface and the surface of the substrate 10 represents the plane angle of the dihedral angle formed by the reflective surface 22 and the surface of the substrate 10. In other words, when the reflective surface 22 is a curved surface, since the reflected light is expanded to a certain extent in a fixed reflection direction, the brightness change will be softer.

[0086] Optionally, the inclination angle θ and the rotation angle φ of the reflective structure 21 both change according to certain rules, so that the optical anti-counterfeiting element 60 presents a relief feature protruding above the optical anti-counterfeiting element 60 or recessed below the optical anti-counterfeiting element 60. At this time, a Fresnel structure is used, and the reflective structure 21 is designed as a micron-level grating to achieve the effect of relief. In particular, the feature formed by the secondary change is the relief itself, and the main change is that the optical anti-counterfeiting element 60 increases the overall effect, and the feature of superimposing a small relief on a large relief can be achieved. For example, lanterns, Huabiao and other features that exist in reality. At the same time, through special design, new features that do not exist in actual models in reality can also be achieved.

[0087] The optical anti-counterfeiting element 60 of the present invention can be used as a label, logo, wide strip, transparent window, coating, etc., and can be attached to various objects through various bonding mechanisms, such as banknotes, credit cards and other high-security products and high-value-added products.

[0088] The present invention also provides an optical anti-counterfeiting product, including the above optical anti-counterfeiting element 60. The optical anti-counterfeiting element 60 includes but is not limited to various high-security products and high-value-added products such as banknotes, credit cards, passports, securities, and various packaging papers, packaging boxes, etc.

[0089] Embodiment 1

[0090] like Figures 1 to 6 As shown, the optical anti-counterfeiting element 60 can be attached to a carrier 70. The carrier 70 can be a banknote, paper, passport, securities, etc., and the material can be paper, polypropylene, polycarbonate, etc.

[0091] In this embodiment, there is a rotation axis 40 and a characteristic straight line 30. When the optical anti-counterfeiting element 60 is tilted forward and backward along the rotation axis 40, a specific dynamic effect will be generated in the direction of the characteristic straight line 30.

[0092] like Figure 2 Shown Figure 1The enlarged view of the middle area 11. As can be seen from the figure, the plane where the optical anti-counterfeiting element 60 is located is the plane xy, on which there is a reflective surface 22, and the reflective surface 22 is a plane. There is a certain angle between the reflective surface 22 and the plane xy where the optical anti-counterfeiting element 60 is located. It can be known from solid geometry that the angle in the solid figure can be decomposed into mutually orthogonal inclination angle θ and rotation angle φ, where the inclination angle θ reflects the inclination of the reflective surface 22 relative to the plane xy where the optical anti-counterfeiting element 60 is located, and the rotation angle φ represents the rotation around the normal perpendicular to the plane xy under the above-mentioned inclination angle θ.

[0093] like Figure 3 The figure shows a cross-sectional view of an optical anti-counterfeiting element 60 along a characteristic line 30. As can be seen from the cross-sectional view, the optical anti-counterfeiting element 60 comprises a substrate 10, on which there is a microstructure layer 20, the microstructure layer 20 is composed of a plurality of reflective structures 21, and the microstructure layer 20 can be divided into a first region 201 and a second region 202 according to the properties of the inclination angle θ and the rotation angle φ of the reflective surface 22. The multiple reflective surfaces 22 in the first region 201 sequentially include a first reflective surface 221, a second reflective surface 222, a third reflective surface 223, and a fourth reflective surface 224, wherein: (1) the inclination angle θ from the first reflective surface 221 to the fourth reflective surface 224 presents an overall decreasing process; (2) within a small range, that is, from the second reflective surface 222 to the fourth reflective surface 224, the inclination angle θ presents a change that first increases and then decreases.

[0094] When the incident light 81 of the external illumination light source 80 irradiates the optical anti-counterfeiting element 60, the light is reflected by the reflection surface 22 and is seen by the observer 90. When the position of the fixed illumination light source 80 remains unchanged and the observation angle is changed, the reflected light 82 of the first reflection surface with the largest inclination angle θ is seen by the observer 90, and the observer 90 feels that the optical anti-counterfeiting element 60 is bright at the position of the first reflection surface 221; when the observation angle becomes smaller, the reflected light 83 of the third reflection surface is seen by the observer 90, and the observer 90 feels that the optical anti-counterfeiting element 60 is bright at the position of the third reflection surface 223, and the bright spot moves from the position of the first reflection surface 221 to the third reflection surface 223; when the observation angle continues to decrease, the reflected light 83 of the third reflection surface is seen by the observer 90, and the observer 90 feels that the optical anti-counterfeiting element 60 is bright at the position of the third reflection surface 223. When the observation angle becomes smaller, the reflected light 84 of the second reflection surface is seen by the observer 90, and the observer 90 feels that the optical anti-counterfeiting element 60 is bright at the position of the second reflection surface 222, and the bright spot moves in the opposite direction from the position of the third reflection surface 223 to the second reflection surface 222; when the observation angle becomes smaller, the reflected light 85 of the fourth reflection surface is seen by the observer 90, and the observer 90 feels that the optical anti-counterfeiting element 60 is bright at the position of the fourth reflection surface 224, and the bright spot moves from the position of the second reflection surface 222 to the fourth reflection surface 224. In other words, as the tilt of the optical anti-counterfeiting element 60 changes, the global dynamic feature presents an overall change from front to back, and at the same time, the localized dynamic feature presents a reciprocating motion back and forth.

[0095] like Figure 4 Shown Figure 3 The distribution of the mid-inclination angle θ, Figure 4 The gray value of the pixel is used to quantitatively represent the inclination angle θ of the reflective surface 22 at that position. Figure 4 It can be seen that in the direction along the characteristic straight line 30, (1) as a whole, the image grayscale changes from white at the upper end position 101 to black at the middle position 102, and then from black to white at the lower end position 103, which means that at the upper end position 101 of the optical anti-counterfeiting element 60, the inclination angle θ of the reflective surface 22 is relatively large; in the process of transitioning to the middle position 102 of the optical anti-counterfeiting element 60, the inclination angle θ of the reflective surface 22 shows a decreasing trend as a whole, and is the smallest at the middle position 102. (2) Locally, the image grayscale shows a localized increase first and then decrease, that is, when the overall inclination angle θ decreases, in the local area 12, the inclination angle θ of the reflective surface 22 first increases, reaches the maximum at the secondary position 121, and then decreases. Similarly, in the range from the upper end position 101 to the middle position 102, the above-mentioned process of increasing first and then decreasing in the local area 12 is repeated.

[0096] like Figure 5 Shown Figure 4 The inclination angle changes shown are along the characteristic straight line 30. Figure 5 It can be seen more clearly that in the process of changing from the upper end position 101 to the middle position 102, the inclination angle θ of the reflecting surface 22 shows a downward trend as a whole, but in the process of decreasing, there are three local change areas, namely, the first change area 1011, the second change area 1012, and the third change area 1013, all of which have a process of first increasing and then decreasing in the trend of the overall inclination angle θ decreasing, that is, the inclination angle is a superposition of the main change and the secondary change, the main change is the inclination angle decreasing, and the secondary change is that the inclination angle θ first increases and then decreases. Similarly, in the process of changing from the middle position 102 to the lower end position 103, the main change of the inclination angle θ is an increase, and the secondary change is an increase first and then a decrease.

[0097] like Figure 6 The figure shows the dynamic features presented at different angles when the optical anti-counterfeiting element 60 tilts forward and backward around the rotation axis 40. It can be seen from the figure that when the optical anti-counterfeiting element 60 tilts forward and backward around the rotation axis 40, the pattern in the optical anti-counterfeiting element 60 as a whole presents a global dynamic feature moving from top to bottom. However, in this overall movement process, the dynamic graphic "trapezoid" also presents a scaling feature, that is, a localized dynamic feature. Therefore, the overall dynamic feature is the superposition of the global dynamic feature and the localized dynamic feature, and has a scaling feature on the basis of the overall rolling feature.

[0098] Embodiment 2

[0099] like Figures 7 to 10As shown, the difference from the first embodiment is that at least a part of all the reflection structures 21 of the microstructure layer 20 form an adjustment structure, and the rotation angle φ of the reflection structures 21 in the adjustment structure changes randomly or pseudo-randomly.

[0100] Specifically, the rotation angle φ changes randomly within the range of 80% - 120% of the standard change design value. Similarly, when the inclination angle θ changes randomly within the range of 80% - 120% of the standard change design value, a matte effect can also be achieved, reducing the dazzling glare and increasing the observable angle.

[0101] For example, when the lateral dimension of the reflection surface 22 is 20 μm, the inclination angle is 10°. By changing the inclination angle to some extent, for example, changing the inclination angle of 10° to 8° - 12°, a part of all the reflection surfaces 22 that could originally be observed at 20° cannot be observed at 20°. At this time, the position occupied by this part of the reflection surface 22 appears black, and this part of the reflection surface 22 will be observed again at an angle of 16° - 24° (excluding 20°). In this way, several noise points appear in the originally continuously changing image, presenting a matte feature.

[0102] For example, in the case as Figure 7 shown, when point light source illumination is used, since the rotation angle φ of each reflection surface 22 is the same, the reflection directions of all the reflection surfaces 22 are the same. When the observer is not in the observation direction, no reflected light enters the observer's eyes, that is, the public cannot observe the dynamic pattern in the optical anti-counterfeiting element 60. When the inclination angle θ is fixed, the rotation angle φ can also have an effect on the appearance dynamic effect. When the rotation angle φ deviates from the original angle by a certain range, a matte effect can also be produced. As Figure 8 shown, when the rotation angle φ of the reflection surface 22 in the optical anti-counterfeiting element 60 is swung to a certain extent, under the same point light source, the reflected light is scattered in different directions, and the observer can observe the reflection surface 22, that is, the public can observe the dynamic pattern in the optical anti-counterfeiting element 60.

[0103] Specifically, the number of the reflection structures 21 in the adjustment structure is n and is divided into m groups. The rotation angles φ of the reflection structures 21 in the same group are the same, and the rotation angles φ of the reflection structures 21 in different groups change randomly or pseudo-randomly, where m < n and the number of the reflection structures 21 in each group is not less than 1.

[0104] It should be noted that in the original design, the number of reflective surfaces 22 of the reflective structure 21 in the adjustment structure at an inclination angle of θ and a rotation angle of φ is n. If the inclination angle θ is kept unchanged and the rotation angle φ is randomly or pseudo-randomly changed to a certain extent, the original rotation angle φ becomes n random or pseudo-random angles centered on φ. Then, strictly speaking, at a fixed angle, the number of reflective surfaces 22 that can be observed becomes 1, so the brightness of the dynamic pattern will be 1 / n of the original. Although this can achieve more observation angles and increase the recognizability of the optical anti-counterfeiting feature, it also greatly reduces the brightness of the optical anti-counterfeiting element 60. Therefore, the randomness of the above-mentioned angle φ can be restricted to a certain extent. It is not simply to make the above-mentioned angle φ completely random, but to divide it into m groups. The reflective surfaces 22 in each group may not be connected together, but their inclination angle θ and rotation angle φ are the same. Although this arrangement reduces randomness, since the number of groups is large enough, the human eye cannot distinguish whether it is completely random or grouped random, so it can still achieve a matte effect, increase the observation angle, and retain sufficient brightness for public observation. This method can achieve higher reflection efficiency and avoid the disadvantage of excessive reduction in image brightness due to excessive dispersion of reflected light caused by using a completely random rotation angle φ.

[0105] It should be noted that the pseudo-random distribution of the rotation angle φ can be generated within a certain angle range using an existing algorithm.

[0106] like Fig. 9 Shown are combinations of reflective surfaces 22 with the same inclination angle and the same rotation angle, a total of 9. Fig.10 The above-mentioned 9 reflection surfaces 22 are divided into 3 groups, namely the first reflection group 225, the second reflection group 226 and the third reflection group 227, and each group has 3 reflection surfaces 22. In the above-mentioned 3 groups of reflection surfaces 22, the inclination angle and the rotation angle of the reflection surface 22 in each group are the same. At this time, when the illumination light source 80 is incident on the optical anti-counterfeiting element 60, the reflected light is modulated by the above-mentioned reflection surface 22 and reflected in 3 directions. The human eye can observe dynamic patterns in 3 directions, and the light intensity in each direction is 1 / 3 of the original total reflected light intensity. When there are enough reflection surfaces 22 with the same inclination angle, even if the rotation direction is not completely random, but facing several specific directions, it can also bring a random effect to the observer, realize the characteristics of matte, and the brightness maintains a certain intensity, comprehensively realizing the characteristics of easy identification under the conditions of multiple angles and multiple light sources.

[0107] Embodiment 3

[0108] like Fig.11 and Fig.12 As shown, the difference from the first embodiment is that the angle α between the rotation axis 40 and the characteristic straight line 30 is different.

[0109] like Fig.11 The gray value in represents the inclination angle of the reflective surface 22 at that position, and the change of the gray value from 255 to 0 represents the change of the inclination angle from large to small. The rotation axis 40 is in the horizontal direction, and the angle α between the characteristic straight line 30 and the rotation axis 40 is 45°.

[0110] like Fig.12 The figure shows a dynamic pattern when the optical anti-counterfeiting element 60 is tilted. As can be seen from the figure, when the optical anti-counterfeiting element 60 is tilted 25° in the negative direction (forward), the dynamic pattern appears from the lower right corner of the optical anti-counterfeiting element 60, and in the process of tilting from the negative direction (forward) to the positive direction (backward), the pattern moves successively to the upper left of the optical anti-counterfeiting element 60, and the angle β between the moving direction of the rolling feature and the rotation direction of the optical anti-counterfeiting element 60 is 45°.

[0111] Embodiment 4

[0112] The difference from the third embodiment is that α and β are different.

[0113] like Figures 13 to 15 As shown, the rotation axis 40 of the optical anti-counterfeiting element 60 and the characteristic straight line 30 may also be parallel. Fig.13 The figure shows the situation where the rotation axis 40 is parallel to the characteristic straight line 30 . At this time, the rotation axis 40 is in a horizontal direction, and the characteristic straight line 30 is also in a horizontal direction, and the two are parallel. Fig.14 The inclination angle of the reflecting surface 22 at the position along the characteristic straight line 30 is shown. Fig.14 It can be seen that the inclination angle changes according to the preset law, showing a main change from large to small and a superposition of secondary changes of large and small oscillations.

[0114] like Fig.15 As shown, when the optical anti-counterfeiting element 60 is tilted forward and backward along the rotation axis 40, the dynamic pattern moves from right to left, wherein the macroscopic movement from right to left is a global dynamic feature, and during the movement, the diamond pattern presents a scaling dynamic feature as a localized dynamic feature. The overall dynamic effect is the superposition of the global dynamic feature and the localized dynamic feature. At this time, the movement direction of the dynamic pattern is horizontal, while the tilt direction is vertical, and the angle β between the two is 90°, presenting an orthogonal rule. Tilt the optical anti-counterfeiting element 60 forward and backward, and the dynamic pattern moves left and right.

[0115] Embodiment 5

[0116] The difference from the first embodiment is that a coating layer 50 is provided on the reflective structure 21 .

[0117] like Fig.16As shown, a coating 50 is deposited on the reflective surface 22, wherein the coating 50 is composed of a reflective layer 51, a dielectric layer 52 and an absorption layer 53. In this embodiment, the reflective layer 51 is aluminum with a thickness of 50nm, the dielectric layer 52 is magnesium fluoride with a thickness of 430nm, and the absorption layer 53 is iron with a thickness of 7nm. Under the above materials and parameters, the reflective layer 51, the dielectric layer 52 and the absorption layer 53 in the coating 50 work together to form a Fabry-Perot resonant cavity structure. When white light is incident, the coating 50 modulates the incident white light, and the reflected light appears golden. When the observation angle is changed, the relative optical path difference of the resonant cavity changes, and the color of the adjustment enhancement also changes accordingly, from golden yellow to green, realizing the light-changing feature that the color changes with the change of the observation angle. When the arrangement pattern of the reflective surface 22 presents a superposition of primary features and secondary features as described in the present application, when the optical anti-counterfeiting element 60 is tilted, while presenting global dynamic features and localized dynamic features, the color also changes from golden yellow to green, further increasing the difficulty of anti-counterfeiting and facilitating public identification.

[0118] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0119] 1. By being set on the characteristic straight line 30, the inclination angle θ of each reflecting surface 22 has a variation period. Within the variation period, the variation of the inclination angle θ of each reflecting surface 22 is divided into a primary variation and a secondary variation. Thus, when the optical anti-counterfeiting element 60 is rotated along the rotation axis 40, the user can observe the global dynamic features and the localized dynamic features. The dynamic features are more complex and delicate, which ensures the anti-counterfeiting effect while facilitating user identification. The dynamic features are clearly visible during the entire process of the user rotating the optical anti-counterfeiting element 60.

[0120] 2. The inclination angle θ and the rotation angle φ can be randomly changed within the range of 80%-120% of the standard change design value. Similar to the random change of the inclination angle θ within the range of 80%-120% of the standard change design value, a matte effect can also be achieved, which can reduce dazzling glare and increase the observable angle.

[0121] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0122] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0123] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0124] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An optical anti-counterfeiting element, characterized in that: Comprising: A substrate (10); A microstructure layer (20), the microstructure layer (20) being located on at least one surface of the substrate (10), at least one characteristic straight line (30) being present in the plane of the microstructure layer (20), along the extending direction of the characteristic straight line (30), the microstructure layer (20) comprising a plurality of reflection structures (21), a reflection surface (22) being present on the side of the reflection structure (21) away from the substrate (10), and the planar angle of the dihedral angle formed by the reflection surface (22) and the surface of the substrate (10) being the inclination angle; Wherein, along the direction of the characteristic straight line (30), all of the inclination angles of the reflection structures (21) at least include one change cycle, within one change cycle, the change of all of the inclination angles is composed of a main change and a secondary change superimposed, when rotating the optical anti-counterfeiting element about a rotation axis (40) in the plane of the optical anti-counterfeiting element, the optical anti-counterfeiting element exhibits a global dynamic characteristic and a local dynamic characteristic due to the main change and the secondary change.

2. The optical anti-counterfeiting element according to claim 1, characterized in that: Within one change cycle, the main change at least includes that the inclination angle of the reflection structure (21) at the start of the change cycle is the largest, and the inclination angle of the reflection structure (21) at the end of the change cycle is the smallest.

3. The optical anti-counterfeiting element according to claim 1, characterized in that: Within one change cycle, the main change at least includes that the inclination angle of the reflection structure (21) at the start of the change cycle is the smallest, and the inclination angle of the reflection structure (21) at the end of the change cycle is the largest.

4. The optical anti-counterfeiting element according to claim 1, characterized in that: Within one change cycle, the main change at least includes that from the start to the end of the change cycle, the inclination angle of the reflection structure (21) changes first decreasing and then increasing.

5. The optical anti-counterfeiting element according to claim 1, characterized in that: Within one change cycle, the secondary change at least includes that the inclination angles of at least a part of all of the reflection structures (21) have at least one alternating change process of increasing and decreasing.

6. The optical anti-counterfeiting element according to claim 1, characterized in that: The main change and the secondary change have standard change design values, and the inclination angle randomly changes within the range of 80% - 120% of the standard change design value.

7. The optical anti-counterfeiting element according to claim 6, characterized in that: The inclination angle randomly changes within the range of 90% - 110% of the standard change design value.

8. The optical anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The angle formed by the reflection structure (21) rotating along the normal line perpendicular to the surface of the substrate (10) forms a rotation angle.

9. The optical anti-counterfeiting element according to claim 8, characterized in that: At least a part of all of the reflection structures (21) of the microstructure layer (20) forms an adjustment structure, and the rotation angles of the reflection structures (21) in the adjustment structure change randomly or pseudo-randomly.

10. The optical anti-counterfeiting element according to claim 9, characterized in that: The number of the reflection structures (21) in the adjustment structure is n and is divided into m groups, the rotation angles of the reflection structures (21) in the same group are the same, the rotation angles of the reflection structures (21) in different groups change randomly or pseudo-randomly, where m < n and the number of the reflection structures (21) in each group is not less than 1.

11. The optical anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The rotation axis (40) and the characteristic straight line (30) are arranged in one-to-one correspondence, and the corresponding rotation axis (40) and characteristic straight line (30) are arranged at an included angle.

12. The optical anti-counterfeiting element according to claim 11, characterized in that: The angle between the correspondingly arranged rotation axis (40) and the characteristic straight line (30) is α, the global dynamic feature comprises a rolling feature, the angle between the moving direction of the rolling feature and the rotation direction of the optical anti-counterfeiting element is β, and the sum of α and β is 90°.

13. The optical anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The optical anti-counterfeiting element further comprises a coating (50), wherein the coating (50) is located on a surface of the microstructure layer (20) that is away from the substrate (10), and the coating (50) is used to enhance a reflection or transmission effect.

14. The optical anti-counterfeiting element according to claim 13, characterized in that: The coating (50) is a single-layer coating.

15. The optical anti-counterfeiting element according to claim 14, characterized in that: The single-layer coating includes one of a single-layer metal coating or a single-layer dielectric coating.

16. The optical anti-counterfeiting element according to claim 13, characterized in that: The coating (50) is a multi-layer coating.

17. The optical anti-counterfeiting element according to claim 16, characterized in that: The multi-layer coating includes one of the coatings formed by alternately stacking a multi-layer dielectric coating, a metal coating and a dielectric coating.

18. The optical anti-counterfeiting element according to claim 17, characterized in that: The multi-layer coating is a Fabry-Perot resonant cavity structure composed of a metal coating, a dielectric coating and a metal coating.

19. The optical anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The characteristic size of the reflective structure (21) is greater than or equal to 1 μm and less than or equal to 500 μm.

20. The optical anti-counterfeiting element according to claim 19, characterized in that: The characteristic size of the reflective structure (21) is greater than or equal to 2 μm and less than or equal to 100 μm.

21. The optical anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The surface of the reflective structure (21) on one side away from the substrate (10) is a plane, and the plane forms the reflective surface (22).

22. The optical anti-counterfeiting element according to any one of claims 1 to 7, characterized in that: The surface of the reflective structure (21) on one side away from the substrate (10) is a curved surface, and the average value of the plane angles of the dihedral angles formed by the tangent plane of each point on the curved surface and the surface of the substrate (10) represents the plane angle of the dihedral angle formed by the reflective surface (22) and the surface of the substrate (10).

23. An optical anti-counterfeiting product, characterized in that: An optical anti-counterfeiting element comprising any one of claims 1 to 22.

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