Machine-readable optical security device

Abstract

An IR and/or UV machine-readable optical security device (e.g., micro-optic security thread) that is made up of at least one IR-absorbing component with a characteristic IR signature detectable at two or more IR-wavelengths, at least one UV-absorbing component with a characteristic UV signature detectable at two or more UV-wavelengths, at least one IR-absorbing component that absorbs IR light and emits light at a different invisible wavelength, at least one UV-absorbing component that absorbs UV light and emits light at a different invisible wavelength, or a combination thereof, is provided. The IR and UV machine-readable features do not interfere with the optical effects projected by the optical material.

What is claimed is: 
     
         1 . A machine-readable optical security device (MrOSD) comprising:
 a spacer layer comprising a first side and a second side;   a layer of focusing elements disposed on the first side of the spacer layer;   an array of image elements disposed on the second side of the spacer layer; and   a machine-readable component (Mr-component) disposed on the second side of the spacer layer and dispersed between image elements of the array of image elements,   wherein the Mr-component is not visible in a visible spectral range when viewed through the layer of focusing elements and the spacer layer, and   wherein the MrOSD further comprises an image layer and the array of image elements is disposed relative to the layer of focusing elements such that a synthetic image is projected by the MrOSD when image elements of the array of image elements are viewed through focusing elements of the layer of focusing elements.   
     
     
         2 . The MrOSD of  claim 1 , wherein the Mr-component is a first infrared (IR) component imparting a machine readable signature (Mr-signature) which includes a machine readable signal (Mr-signal) within an IR spectral range. 
     
     
         3 . The MrOSD of  claim 2 , wherein the Mr-component provides at least two Mr-signals within an invisible spectral range. 
     
     
         4 . The MrOSD of  claim 1 , wherein the Mr-component provides an Mr-signal in a near infrared spectral range. 
     
     
         5 . The MrOSD of  claim 1 , wherein the Mr-component imparts an Mr-signature that includes a first absorption at a first wavelength and a second absorption at a second wavelength where the first absorption is lower than the second absorption and the first wavelength is lower than the second wavelength. 
     
     
         6 . The MrOSD of  claim 1 , wherein image elements of the array of image elements comprise a material contrasting with the spacer layer. 
     
     
         7 . The MrOSD of  claim 1 , wherein the Mr-component is a first ultraviolet (UV) component imparting an Mr-signature which includes an Mr-signal within a UV spectral range. 
     
     
         8 . The MrOSD of  claim 1 , wherein the Mr-component comprises an IR-taggant which absorbs infrared light of a first wavelength and emits light at a second wavelength. 
     
     
         9 . The MrOSD of  claim 1 , wherein the Mr-component comprises a UV-taggant which absorbs ultraviolet light of a first wavelength and emits light at a second wavelength. 
     
     
         10 . The MrOSD of  claim 1 , wherein the MR-component comprises an IR-taggant selected from a substituted phthalocyanine, a naphthalocyanine, a metal-containing phthalocyanine, or a poly-substituted phthalocyanine. 
     
     
         11 . The MrOSD of  claim 1 , wherein the MR-component is an IR-taggant comprising a benzenethiol-substituted copper-phthalocyanine. 
     
     
         12 . The MrOSD of  claim 1 , wherein the Mr-component provides at least two signals within a UV spectral range. 
     
     
         13 . The MrOSD of  claim 1 , wherein the Mr-component provides at least two signals within an IR spectral range. 
     
     
         14 . The MrOSD of  claim 1 , further comprising an opaque backcoat layer contacting the array of image elements and the Mr-component.