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US 2014/0306441 A1Published application
Security devices and methods of manufacture thereof
AssigneeDe La Rue International Limited
InventorAdam Lister
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AssigneeDe La Rue International Limited
InventorAdam Lister
Estimating the term…
A method of manufacturing a security device including: conveying a substrate web including a photosensitive film along a transport path; exposing the photosensitive film to radiation of a predetermined wavelength through a mask, wherein the mask includes a predetermined pattern of regions which are substantially opaque to radiation of the predetermined wavelength and at least semi-transparent to radiation of the predetermined wavelength, respectively; during the exposure, moving the mask alongside the substrate web along at least a portion of the transport path at substantially the same speed as the substrate web, such that there is substantially no relative movement between the mask and the substrate web; and heating the substrate web including the exposed photosensitive film. In this way, regions of the photosensitive film exposed to the radiation of the predetermined wavelength undergo an increase in optical density such that the photosensitive film displays a reproduction of the predetermined pattern.
A method of manufacturing at least part of a security device, the method comprising:
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An apparatus for manufacturing at least part of a security device, comprising:
A security device for an object of value, comprising a first photosensitive film exhibiting a first pattern of regions of relatively high and relatively low optical density, respectively, the relatively high optical density regions of the first pattern having bubbles within the photosensitive film arising from exposure of the regions to radiation of a predetermined wavelength to which the first photosensitive film is responsive and subsequent or concurrent heating.
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A security device comprising a substrate which is substantially visually transparent, the substrate carrying on one side thereof at least a first array of elements arranged to form lines which are laterally spaced from one another, each element having a raised surface profile relative to the surface of the substrate and having a higher optical density than that of the substrate in the spaces between the elements, wherein the lines formed by the elements of the first array are aligned along a first direction whereby the appearance of the device when viewed from either side of the substrate changes at different angles of view, generating a latent effect.
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Dependencies are inferred from the claim text.