A subwavelength grating displaying a colored image exhibiting a color corresponding to a grating period of a subwavelength grating in reflection directions including a specular reflection direction. A relief surface displaying a reflection image in monochromatic reflected light in reflection directions including a direction different from the specular reflection direction. An optical element has a first state in which neither a colored image nor a reflection image is displayed, a second state in which the colored image is mainly displayed, and a third state in which the reflection image is mainly displayed. A plane in which the optical element is disposed and a plane including a line of sight of an observer form an observation angle therebetween. The optical element is observed in any of the first, second and third states according to the observation angle.

An IR and/or UV machine-readable optical security device (e.g., micro-optic security thread) that is made up of at least one IR-absorbing component with a characteristic IR signature detectable at two or more IR-wavelengths, at least one UV-absorbing component with a characteristic UV signature detectable at two or more UV-wavelengths, at least one IR-absorbing component that absorbs IR light and emits light at a different invisible wavelength, at least one UV-absorbing component that absorbs UV light and emits light at a different invisible wavelength, or a combination thereof, is provided. The IR and UV machine-readable features do not interfere with the optical effects projected by the optical material.

An IR and/or UV machine-readable optical security device (e.g., micro-optic security thread) that is made up of at least one IR-absorbing component with a characteristic IR signature detectable at two or more IR-wavelengths, at least one UV-absorbing component with a characteristic UV signature detectable at two or more UV-wavelengths, at least one IR-absorbing component that absorbs IR light and emits light at a different invisible wavelength, at least one UV-absorbing component that absorbs UV light and emits light at a different invisible wavelength, or a combination thereof, is provided. The IR and UV machine-readable features do not interfere with the optical effects projected by the optical material.

A color developing structure that exhibits good color development and ensures a desired transmittance while diffusing reflected light in multiple directions. A color developing structure includes a concave-convex layer in which a first surface has a concave-convex structure, and a reflective layer formed on the first surface to extend along the concave-convex structure. A convex surface of the concave-convex structure has a first pattern composed of a plurality of strip portions in plan view. The strip portion has a width in a first direction and a length in a second direction perpendicular to the first direction. The width is smaller than the wavelength of the incident light, and a standard deviation of the lengths of the plurality of strip portions is larger than a standard deviation of the widths.

A color developing structure that exhibits good color development and ensures a desired transmittance while diffusing reflected light in multiple directions. A color developing structure includes a concave-convex layer in which a first surface has a concave-convex structure, and a reflective layer formed on the first surface to extend along the concave-convex structure. A convex surface of the concave-convex structure has a first pattern composed of a plurality of strip portions in plan view. The strip portion has a width in a first direction and a length in a second direction perpendicular to the first direction. The width is smaller than the wavelength of the incident light, and a standard deviation of the lengths of the plurality of strip portions is larger than a standard deviation of the widths.

The present invention relates to a security device comprising a colloidal crystal which exhibits excellent visibility and is also easily manufactured. The security device, according to the present invention, comprises: a substrate; a groove part formed on the substrate; a colloidal crystal positioned in the groove part; and an aging film. The security device, according to the present invention, exhibits excellent security and visibility, and thus may be used for securities, credit cards, security cards, anti-forgery products, etc.

The present invention relates to a security device comprising a colloidal crystal which exhibits excellent visibility and is also easily manufactured. The security device, according to the present invention, comprises: a substrate; a groove part formed on the substrate; a colloidal crystal positioned in the groove part; and an aging film. The security device, according to the present invention, exhibits excellent security and visibility, and thus may be used for securities, credit cards, security cards, anti-forgery products, etc.

An optically variable security element is provided for protecting objects of value. The reflective area region includes two independent relief structures, which are arranged at different levels in the z-direction and form a lower-level relief structure and a higher-level relief structure. The higher-level relief structure is supplied with a first reflection-enhancing coating following the relief profile, and the lower-level relief structure is supplied with a second reflection-enhancing coating following the relief profile. The first reflection-enhancing coating is formed in the visible spectral range with a reflection and transmission in the visible spectral range, so that the higher-level relief structure shows a first optically variable effect in a first color, and the lower-level relief structure shows a second optically variable effect through the first reflection-enhancing coating, wherein the second optically variable effect shows itself in a second, different color.

An optically variable security element is provided for protecting objects of value. The reflective area region includes two independent relief structures, which are arranged at different levels in the z-direction and form a lower-level relief structure and a higher-level relief structure. The higher-level relief structure is supplied with a first reflection-enhancing coating following the relief profile, and the lower-level relief structure is supplied with a second reflection-enhancing coating following the relief profile. The first reflection-enhancing coating is formed in the visible spectral range with a reflection and transmission in the visible spectral range, so that the higher-level relief structure shows a first optically variable effect in a first color, and the lower-level relief structure shows a second optically variable effect through the first reflection-enhancing coating, wherein the second optically variable effect shows itself in a second, different color.

The present invention relates to a flexible package for providing security against counterfeiting. The flexible package includes a plurality of panels made of a flexible polymeric substrate, which further includes a front panel, a rear panel arranged in opposite to the front panel defining an interior space of the package and at least one longitudinal narrow window portion on at least one panel. A transparent or translucent polymeric security strip is having a clear high barrier coating, is sealed over the window portion towards inner side of the panel overlapping the edges of the window portion but not overlapping the entire panel, a security feature is provided on the strip on at least one of its surface at a predefined location or random places or all over the strip surface for securing the package against counterfeiting.