The present invention provides an image engraving apparatus capable of precisely driving a stylus to improve accuracy of image engraving. The image engraving apparatus has a vibration actuator fixed to a floating base and having an output portion configured to output vibration generated by deformation of piezoelectric elements, a stylus supported with a stylus holder to be vibrated and engrave an image on a medium to be engraved, a supporting spring supporting the stylus holder, and a retainer positionally adjustably supported to the floating base to come into contact with the medium.

A security sheet including at least one paper substrate, at least one watermark produced in the paper substrate, the watermark having an exterior outline, at least one aperture of regular edge, produced by ablation of the paper substrate, and at least one security film that is at least partially superposed on the watermark and on the aperture. In the sheet, the at least one aperture lies inside the watermark, such as bounded by its exterior outline.

A security sheet including at least one paper substrate, at least one watermark produced in the paper substrate, the watermark having an exterior outline, at least one aperture of regular edge, produced by ablation of the paper substrate, and at least one security film that is at least partially superposed on the watermark and on the aperture. In the sheet, the at least one aperture lies inside the watermark, such as bounded by its exterior outline.

An optically variable security element wherein the areal expansion whereof defines a z direction standing perpendicularly thereon, and has a multicolored, reflective areal region. The areal region includes two relief structures arranged at different height levels in the z direction. The relief structures are each supplied with an ink coating which produce a different color impression. The ink coating of the relief structure disposed at a higher level is configured in the feature region as a regular or irregular grid with grid elements and grid spaces. The dimensions of the grid elements and/or grid spaces are below 140 μm at least in one direction, so that, in the feature region, for a viewer from at least one viewing angle, the ink coating of the relief structure disposed at a lower level is visible through the grid spaces of the ink coating of the relief structure disposed at a higher level.

A sheet, including a substrate having a surface, wherein the surface includes a first marking that defines a boundary of a hollow flake, and a second marking that defines a boundary of a solid flake; wherein the first marking and the second marking are each, independently, configured to protrude from a plane of the surface or depress down from the plane of the surface; and wherein the first marking surrounds the second marking is disclosed. A complementary set of flakes, and a method of making the complementary set of flakes are also disclosed.

A micro-optic security device with zonal color transitions includes a planar array of focusing elements, an image icon layer including a plurality of retaining structures, the plurality of retaining structures defining isolated volumes at a first depth within the image icon layer, a first zone of image icons, the first zone of image icons having a first predefined subset of the plurality of retaining structures, wherein the isolated volumes of retaining structures of the first predefined subset of the plurality of retaining structures contain cured pigmented material of a first color, and a second zone of image icons, the second zone of image icons including a second predefined subset of the plurality of retaining structures, wherein the isolated volumes of retaining structures of the second predefined subset of the plurality of retaining structures contain cured pigmented material of a second color, wherein the second color contrasts with the first color.

An aspect of the disclosure relates to a thin film including an amorphous array of particles including a top surface and a bottom surface opposing each other, the thin film exhibiting thin film interference and further coherent scattering from the amorphous array of particles, wherein the thin film may include first regions and second regions, wherein the thin film interference of the second regions may be suppressed as compared to the first regions. Another aspect of the disclosure relates to a product including an indicium including a thin film in accordance with any of the previous claims, wherein the indicium may include an encoded pattern encoded by the relative position of the second regions to the first regions, wherein the encoded pattern may be visible under specular reflection of light of a pre-determined wavelength. Another aspect of the disclosure relates to a method of producing a thin film.

An aspect of the disclosure relates to a thin film including an amorphous array of particles including a top surface and a bottom surface opposing each other, the thin film exhibiting thin film interference and further coherent scattering from the amorphous array of particles, wherein the thin film may include first regions and second regions, wherein the thin film interference of the second regions may be suppressed as compared to the first regions. Another aspect of the disclosure relates to a product including an indicium including a thin film in accordance with any of the previous claims, wherein the indicium may include an encoded pattern encoded by the relative position of the second regions to the first regions, wherein the encoded pattern may be visible under specular reflection of light of a pre-determined wavelength. Another aspect of the disclosure relates to a method of producing a thin film.

Disclosed herein is a method for encoding an illustration on a target surface, where the illustration may be visible when light is shone on the surface from a light source with a predetermined position. The method may include converting the illustration into a grayscale illustration, specifying the position of the light source; generating a three dimensional surface having a grid of smaller surfaces thereon, where each smaller surface may represent a corresponding pixel of the grayscale illustration. Each smaller surface may be oriented with respect to the light source such that reflected light from each smaller surface has a reflection intensity equal to the light intensity of the corresponding pixel of the greyscale illustration; and making the target surface out of a material using the generated three dimensional surface as a template.

Example embodiments of biodegradable cards and systems and methods making the same are provided. A biodegradable card can comprise a biodegradable substrate, a magnetic particle slot within the biodegradable substrate configured to receive magnetic particles, a high coercivity magnetic stripe comprising magnetic particles printed on the biodegradable substrate and encoded with payment account data, and a biodegradable water resistant coating, wherein the coating covers at least the magnetic stripe.