The present invention provides an improved security document having a “see-through” security feature that protects a window of the security document in which personalization information may be displayed, such as an image of the authorized document holder. The “see-through” security feature is provided by front and back side images, such as text (e.g. micro-text or encoded indicia), graphics or other image type, that may be laser marked onto the document substrate from a front side thereof through the window to a back side of the window. At least a part of the front image and at least a part of the back image are in front-to-back registration in window, the registration of the images being subject to verification by suitable inspection of the window. The front and back images may be partial images of a composite image when joined together at a juncture with the front-to- back registration of the partial images located at the juncture so that the images together have an appearance of the composite image in the window. Ahernatively, at least a part of the first and second images may be identical with the front-to-back registration of the images located at least one of the identical parts so that the first and second images have an appearance in the window of a single image at those identical parts of the front-to-back registration.

The invention relates to an absorbent medium for improving the overprintability, in particular by inkjet printing, of a security element, in particular an optically variable security element, comprising a binder, at least one pigment and an in particular aqueous solvent. The invention furthermore relates to a transfer film with an absorbent layer made of such an absorbent medium as well as a method for personalizing a security element using such a transfer film.

The invention relates to an absorbent medium for improving the overprintability, in particular by inkjet printing, of a security element, in particular an optically variable security element, comprising a binder, at least one pigment and an in particular aqueous solvent. The invention furthermore relates to a transfer film with an absorbent layer made of such an absorbent medium as well as a method for personalizing a security element using such a transfer film.

There is provided a luminescent medium which requires difficult analysis of light emitted from a luminescent material of the medium. A luminescent medium 10 includes a substrate 11, and a luminescent material 12 comprising a first luminescent material 12A which, when irradiated with visible light, infrared light or ultraviolet light, emits first infrared light “a”, and a second luminescent material 12B which, when irradiated with visible light, infrared light or ultraviolet light, emits second infrared light “b”. The first luminescent material 12A is formed in a first planar area 11A, and the second luminescent material 12B is formed in a second planar area 11B. The first planar area 11A and the second planar area 11B overlap each other, forming an overlapping planar area 11C in which the luminescent materials 12A and 12B each have a concentration gradation.

An optical 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. In some examples, individual ones of the first and second segments can comprise specular reflecting, transparent, diffusely reflecting, and/or diffusely transmissive features. In some examples, individual ones of the first and second segments can comprise transparent and non-transparent regions. Some examples can incorporate more than one region producing an optical effect.

A security device (100, 600, 700) includes one or more arrangements of image icons (100a, 110b, 615, 715), one or more arrangements of refractive image icon focusing elements (120, 605, 705), and a sealing layer (127, 600, 1005) which includes an organic resin and nanoparticles. Further, the one or more arrangements of refractive image icon focusing elements is disposed above the one or more arrangements of image icons such that a portion of the one or more arrangements of refractive image icon focusing elements forms a synthetic image of a portion of the one or more arrangements of image icons. Still further, the one or more arrangements of refractive image icon focusing elements contact the sealing layer along a non-planar boundary.

A method of forming a security device includes selectively providing a high refractive index (HRI) layer to a first outwardly facing surface of a security device substrate, the HRI layer having a substantially transparent host material and particles having a dimension along at least one axis less than 200 nm, such that they are substantially non-scattering to visible light and the HRI layer is substantially transparent to visible light, and wherein; the particles have a refractive index of at least 1.8 and are present within the host material in a proportion such that the resultant refractive index of the HRI layer is at least 1.6. A corresponding security device, as well as security articles and security documents, are also disclosed.

A method of forming a security device includes selectively providing a high refractive index (HRI) layer to a first outwardly facing surface of a security device substrate, the HRI layer having a substantially transparent host material and particles having a dimension along at least one axis less than 200 nm, such that they are substantially non-scattering to visible light and the HRI layer is substantially transparent to visible light, and wherein; the particles have a refractive index of at least 1.8 and are present within the host material in a proportion such that the resultant refractive index of the HRI layer is at least 1.6. A corresponding security device, as well as security articles and security documents, are also disclosed.

A data carrier with a cover layer, a base layer, and an information layer arrangement. The information layer arrangement includes at least a first information layer and a second information layer arranged after the first information layer along an extension direction. The first information layer and the second information layer have different optical properties, and the information layer arrangement has an unmodified region and at least one modified region, the at least one modified region having at least one recess extending at least partially into the first information layer along the extension direction. The at least one modified region is configured to reflect incident electromagnetic waves whereby a first reflection spectrum is generated, the unmodified region is configured to reflect said incident electromagnetic waves whereby a second reflection spectrum is generated, the first reflection spectrum being different from the second reflection spectrum.

Systems, devices, methods, and instructions for travel document validation, including receiving data for one or more travel documents, generating a set of features for artificial intelligence model training, validating, and testing, upon receiving data for a plurality of travel documents, data from a first subset of travel documents is used to train an artificial intelligence model, a second subset of travel documents is used to validate the artificial intelligence model, and a third subset of travel documents is used to test the artificial intelligence model.