Patent ID: 8357448
Filing Date: 2013-01-22
Classification: B32B,Y10T

Abstract:
1. An identification device for marking an article, the identification device having a low emissivity relative to an emissivity of said article at thermal infrared wavelengths, said device comprising an optical filter configured to have direct reflectivity at thermal infrared wavelengths, said filter comprising a plurality of layers including: a first layer arranged to be absorbing throughout substantially the whole of the visible spectrum such that the first layer appears visually dark to the unaided eye; a second layer arranged to be reflective at thermal infrared wavelengths; and a substrate layer comprised of a polymer film, wherein the first and second layers are arranged in a stack upon said substrate layer such that the second layer is disposed between the first layer and the substrate layer, wherein the first layer is arranged to be substantially transmissive at thermal infrared wavelengths.