An image display element includes a display layer configured to display first to n-th (where n is an integer of 2 or more) images; a light-shielding pattern layer disposed opposite to the display layer and having alternately disposed light-shielding parts and light-transmitting parts, and a transparent layer disposed between the display layer and the light-shielding pattern layer. The display layer contains a coloring matter, where the coloring matter forms first to n-th images; each of the first to n-th images is divided in a discrete manner corresponding to the arrangement pattern of the light-transmitting parts; and an image visible through the light-shielding pattern layer changes depending on the angle from which the light-shielding pattern layer is viewed.

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.

The present invention firstly relates to a security feature for a security or value document. The security feature comprises a zinc sulfide lurninophore in the form of particles. The zinc sulfide lurninophore has the general chemical formula ZnS: Cu.sub.x, M.sub.y, X.sub.z; here, M represents one or more elements from a group comprising the chemical elements Co, In and Ni; X represents one or more elements from a group comprising the halides F, Cl, Br and I; and the following applies: 0 < x < 0.002 and 0 ≤ y < 0.00015 and 0 ≤ z < 0.00050. The particles each have cubic phase portions and hexagonal phase portions. When excited by an electrical field, the zinc sulfide luminophore emits a first radiation in the range of the light spectrum between 580 nm and 780 nm. When excited by heating the luminophore to a temperature between 100° C. and 150° C., the zinc sulfide luminophore emits a second radiation in the light spectrum. Furthermore, the invention relates to a security and value document, which may for example be a bank note or a passport, an identity card, a driving license or a postage stamp. The invention also relates to a method for detecting and/or verifying the security feature according to the invention.

The present invention firstly relates to a security feature for a security or value document. The security feature comprises a zinc sulfide lurninophore in the form of particles. The zinc sulfide lurninophore has the general chemical formula ZnS: Cu.sub.x, M.sub.y, X.sub.z; here, M represents one or more elements from a group comprising the chemical elements Co, In and Ni; X represents one or more elements from a group comprising the halides F, Cl, Br and I; and the following applies: 0 < x < 0.002 and 0 ≤ y < 0.00015 and 0 ≤ z < 0.00050. The particles each have cubic phase portions and hexagonal phase portions. When excited by an electrical field, the zinc sulfide luminophore emits a first radiation in the range of the light spectrum between 580 nm and 780 nm. When excited by heating the luminophore to a temperature between 100° C. and 150° C., the zinc sulfide luminophore emits a second radiation in the light spectrum. Furthermore, the invention relates to a security and value document, which may for example be a bank note or a passport, an identity card, a driving license or a postage stamp. The invention also relates to a method for detecting and/or verifying the security feature according to the invention.

Transaction and identification cards formed from raw bamboo assemblies including one or more raw bamboo layers optionally adhered to a paper backer. In one embodiment, a single raw bamboo assembly is adhered to a base or core substrate. Optionally, a second bamboo assembly is coupled to the first bamboo assembly, with or without a core layer sandwiched in between the bamboo assemblies, such that the card's top face includes a first bamboo layer and the card's bottom face includes a second bamboo layer. One or more image or graphic layers are then either printed directly onto the raw bamboo layer or laminated thereto. Optional protective substrates, films, or coatings are applied to or over the bamboo assembly to protect by sandwiching the one or more ink or printed layers between the protective layer and the raw bamboo layers.

Transaction and identification cards formed from raw bamboo assemblies including one or more raw bamboo layers optionally adhered to a paper backer. In one embodiment, a single raw bamboo assembly is adhered to a base or core substrate. Optionally, a second bamboo assembly is coupled to the first bamboo assembly, with or without a core layer sandwiched in between the bamboo assemblies, such that the card's top face includes a first bamboo layer and the card's bottom face includes a second bamboo layer. One or more image or graphic layers are then either printed directly onto the raw bamboo layer or laminated thereto. Optional protective substrates, films, or coatings are applied to or over the bamboo assembly to protect by sandwiching the one or more ink or printed layers between the protective layer and the raw bamboo layers.

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.

Methods and apparatus for invisible luminescent protection for financial and identification documents are described herein. An example apparatus includes an illuminating source to illuminate a sample with light having a first wavelength, a photo element to detect light having a second wavelength and to capture an image of a first pattern printed on the sample, wherein the first pattern is printed on a first area of the sample with clear ink containing inorganic, ceramic particles having a mean diameter of less than one micron and having luminescent properties such that when the particles are illuminated with light having the first wavelength, they emit light having the second wavelength.