A display technique capable of displaying special images. A display includes a light shielding layer having a plurality of slits arranged at intervals in a width direction thereof, and an image recording layer that faces a first major surface of the light shielding layer at an interval and in which a latent image is recorded, the latent image being rendered visible by being partially concealed by the light shielding layer.

A security element, e g. for an ID card (7) or passport, banknote, ticket, etc, comprises a plurality of superposed layers (8a, 8b, 8c, 8d) and a security image or object (1, 2, 3, 4, 5, 6, 7) comprising a plurality of discrete security components, each said discrete security component constituting or providing a portion of the complete security image or object, which portion is less than the hole of the security image or object, wherein each said discrete security component is provided or formed on or within a respective one of the said plurality of superposed layers of the element (7). The layers can be laminated together. The components can be: a security rainbow hologram/DOVID (1); a tactile security feature (2); a 3D holographic optical element (3); an IR visible printing (4); an UV visible printing (5); a colour switch printing (6).

A security system, such as a banknote, comprises: i) a substrate, ii) a first ink, which is applied on at least a part of at least one surface of the substrate, wherein the first ink includes at least one IR luminescent dye and/or at least one IR luminescent pigment, and iii) a second non-luminescent ink, which is applied on at least a part of at least one surface of the substrate onto which the first ink is/are applied, wherein the second ink includes at least one non-luminescent IR absorbing pigment and/or a least one non-luminescent IR absorbing dye, wherein the first ink and the second ink at least partially overlap on the at least one surface of the substrate, wherein the second ink is applied in the overlapping area onto the first ink, and wherein the emission spectrum of the first ink and the absorption spectrum of the second ink at least partially overlap.

A security system, such as a banknote, comprises: i) a substrate, ii) a first ink, which is applied on at least a part of at least one surface of the substrate, wherein the first ink includes at least one IR luminescent dye and/or at least one IR luminescent pigment, and iii) a second non-luminescent ink, which is applied on at least a part of at least one surface of the substrate onto which the first ink is/are applied, wherein the second ink includes at least one non-luminescent IR absorbing pigment and/or a least one non-luminescent IR absorbing dye, wherein the first ink and the second ink at least partially overlap on the at least one surface of the substrate, wherein the second ink is applied in the overlapping area onto the first ink, and wherein the emission spectrum of the first ink and the absorption spectrum of the second ink at least partially overlap.

The present invention relates to metal oxide nanoparticles, a method for their production, a coating, or printing composition, comprising the metal oxide nanoparticles and the use of the composition for coating of surface relief micro- and nanostructures (e.g. holograms), manufacturing of optical waveguides, solar panels, light outcoupling layers for display and lighting devices and anti-reflection coatings. Holograms are bright and visible from any angle, when coated, or printed with the composition, comprising the metal oxide nanoparticles.

A security or identification device comprises a membrane laser structure configured to be optically pumped. The membrane laser structure comprises a flexible emission layer comprising a gain material; and one or more structures formed in or associated with the flexible emission layer and configured to provide optical feedback in the emission layer to produce a laser light output having at least one property representing an identifier.

The use of a modified reduced indium tin oxide to provide a security image wherein the modified reduced indium tin oxide is obtained by heating indium tin oxide in a reducing atmosphere at a temperature of from 300 to 500° C.; and contacting the reduced indium tin oxide with an organophosphorus compound.

The use of a modified reduced indium tin oxide to provide a security image wherein the modified reduced indium tin oxide is obtained by heating indium tin oxide in a reducing atmosphere at a temperature of from 300 to 500° C.; and contacting the reduced indium tin oxide with an organophosphorus compound.

A multilayered printed matter includes a group of print layers formed on a medium. The group of layers include a front layer and a back layer on which patterns are printed, a white layer, and a black layer. The white layer is interposed between the front layer and the back layer to conceal the back layer to be invisible from the side of the front layer. The white layer reflects incident light from the side of the front layer to allow the front layer to be visible from the side of the front layer. The black layer is interposed between the white layer and the back layer to conceal the back layer to be invisible from the side of the front layer. In comparison between the black layer and the white layer that are equal in thickness, the black layer exerts a higher light blocking effect than the white layer.

A security device includes an array of lenses and a plurality of first and second segments disposed under the array of lenses. At a first viewing angle, the array of lenses presents a first image for viewing without presenting the second image for viewing, and at a second viewing angle different from the first viewing angle, the array of lenses presents for viewing the second image without presenting the first image for viewing. At least one first or second segment can include one or more microstructures or one or more nanostructures configured to produce one or more colors for the first or second image.