An identification method for performing authenticity determination on an identification medium having code information and having a variable light pattern portion whose pattern of observed light varies upon a change in an observation angle and for performing reading of the code information includes generating, for captured image data of the variable light pattern portion of the identification medium, reference image data corresponding to the observation angle as the angle of an imaging direction of the captured image data with respect to a reference line of an observation target surface of the identification medium by a reference image generation unit, obtaining a degree of similarity between the captured image data and the reference image data, and performing, based on whether the degree of similarity exceeds a preset threshold, authenticity determination about whether the identification medium is authentic and reading the code information.

An identification method for performing authenticity determination on an identification medium having code information and having a variable light pattern portion whose pattern of observed light varies upon a change in an observation angle and for performing reading of the code information includes generating, for captured image data of the variable light pattern portion of the identification medium, reference image data corresponding to the observation angle as the angle of an imaging direction of the captured image data with respect to a reference line of an observation target surface of the identification medium by a reference image generation unit, obtaining a degree of similarity between the captured image data and the reference image data, and performing, based on whether the degree of similarity exceeds a preset threshold, authenticity determination about whether the identification medium is authentic and reading the code information.

Provided is an information display medium that can enhance a forgery prevention effect. An information display medium (100) includes a light reflection layer (20) made of a metal or a metallic oxide and partially or fully placed on one surface of a substrate, and the light reflection layer (20) includes a first region (30) where first information is displayed by either of or a combination of an outline shape and a shape of an uneven region, and a second information display region (21a) where identification information formed by partial material removal of the light reflection layer (20), the second information display region being set to partially or fully overlap with the light reflection layer (20) where the first information is displayed in the first region (30).

A method of manufacturing an image pattern for a security device includes providing a metallised substrate; applying a first photosensitive resist layer to a substrate first metal layer exposing the resist layer to radiation; exposing the resist layer to a first reactant substance; activating a cross linking agent in the resist layer; exposing first and second pattern elements of the resist layer to radiation of a wavelength to which the resist layer is responsive whereupon newly-exposed first pattern elements of the first photosensitive resist layer react, resulting in increased solubility by the second etchant substance, the second pattern elements remaining relatively insoluble by the second etchant substance; and applying first and second etchant substances to the substrate whereupon the first pattern elements of both the first resist layer and the first metal layer are dissolved, the remaining second pattern elements of the first metal layer forming an image pattern.

A method of manufacturing an image pattern for a security device includes providing a metallised substrate; applying a first photosensitive resist layer to a substrate first metal layer exposing the resist layer to radiation; exposing the resist layer to a first reactant substance; activating a cross linking agent in the resist layer; exposing first and second pattern elements of the resist layer to radiation of a wavelength to which the resist layer is responsive whereupon newly-exposed first pattern elements of the first photosensitive resist layer react, resulting in increased solubility by the second etchant substance, the second pattern elements remaining relatively insoluble by the second etchant substance; and applying first and second etchant substances to the substrate whereupon the first pattern elements of both the first resist layer and the first metal layer are dissolved, the remaining second pattern elements of the first metal layer forming an image pattern.

A method for producing a security element for security papers, valuable documents or the like, includes a carrier having on its top side micro-imaging elements and on its underside structures which, together with the microimaging elements, image a motif in front of the top side of the carrier; the position of the motif being is dependent on the viewing angle.

A method for producing a security element for security papers, valuable documents or the like, includes a carrier having on its top side micro-imaging elements and on its underside structures which, together with the microimaging elements, image a motif in front of the top side of the carrier; the position of the motif being is dependent on the viewing angle.

A method of manufacturing an image pattern for a security device is disclosed. The method comprises: (a) providing a metallised substrate comprising a substrate material having a first metal layer thereon on a first surface of the substrate material, the first metal layer being soluble in a first etchant substance; (b) applying a first resist layer to the first metal layer, the first resist layer comprising a resist material; (c) bringing the first resist layer into contact with a relief structure comprising a support carrying one or more protrusions thereon, the one or more protrusions each extending away from the support to a distal tip, whereupon at least one of the protrusion(s) extends into the first resist layer; (d) while the first resist layer and the relief structure are in contact, controlling the metallised substrate and/or the relief structure to achieve relative movement between the metallised substrate and at least the tip of the at least one of the protrusion(s) along a movement direction, such that the at least one of the protrusion(s) extending into the first resist layer expels a corresponding at least one portion of the resist material from a corresponding at least one region of the metallised substrate; (e) separating the first resist layer from the relief structure such that the at least one of the protrusion(s) is removed from the first resist layer, leaving the resist material remaining on the metallised substrate outside the at least one region, thereby forming a pattern of one or more first pattern elements in which the resist material is present and one or more second pattern elements, corresponding to the at least one region, in which the resist material is substantially absent; and (f) applying the first etchant substance to the metallised substrate whereupon the second pattern elements of the first metal layer are dissolved, the remaining first pattern elements of the first metal layer forming an image pattern.

A method of manufacturing an image pattern for a security device is disclosed. The method comprises: (a) providing a metallised substrate comprising a substrate material having a first metal layer thereon on a first surface of the substrate material, the first metal layer being soluble in a first etchant substance; (b) applying a first resist layer to the first metal layer, the first resist layer comprising a resist material; (c) bringing the first resist layer into contact with a relief structure comprising a support carrying one or more protrusions thereon, the one or more protrusions each extending away from the support to a distal tip, whereupon at least one of the protrusion(s) extends into the first resist layer; (d) while the first resist layer and the relief structure are in contact, controlling the metallised substrate and/or the relief structure to achieve relative movement between the metallised substrate and at least the tip of the at least one of the protrusion(s) along a movement direction, such that the at least one of the protrusion(s) extending into the first resist layer expels a corresponding at least one portion of the resist material from a corresponding at least one region of the metallised substrate; (e) separating the first resist layer from the relief structure such that the at least one of the protrusion(s) is removed from the first resist layer, leaving the resist material remaining on the metallised substrate outside the at least one region, thereby forming a pattern of one or more first pattern elements in which the resist material is present and one or more second pattern elements, corresponding to the at least one region, in which the resist material is substantially absent; and (f) applying the first etchant substance to the metallised substrate whereupon the second pattern elements of the first metal layer are dissolved, the remaining first pattern elements of the first metal layer forming an image pattern.

Disclosed herein are devices that change their appearance and/or physical properties when under an external influence, and methods for their production and use. Such devices may be used as features of any type of items, documents, billboards, posters, display devices, advertisements and other items etc. and may be adapted to include decipherable content. Such devices also afford new techniques for a user to check quickly and easily whether the item is a legitimate or a counterfeit copy, either by hand-manipulation of the device, or with the assistance of an additional screening tool.