Security Device Having A Segmented Layer

Abstract

A security article includes a light transmissive substrate having a first surface and an opposing second surface, with the first surface having an embossed region with an optical diffraction pattern or a holographic image pattern. A color shifting optical coating is formed on the substrate such as on the opposing second surface, with the optical coating providing an observable color shift as the angle of incident light or viewing angle changes. The security article can be used in a variety of applications and products to provide for enhanced security measures such as anticounterfeiting.

1 - 7 . (canceled)  
   
   
       8 . A security article comprising: 
 a light transmissive substrate having a first surface and an opposing second surface, the first surface having an optical interference pattern; and    a color shifting optical coating on the first or second surface of the substrate, the optical coating providing an observable color shift as the angle of incident light or viewing angle changes;    wherein a segmented layer allows partial viewing of some regions while obscuring viewing of other regions.    
   
   
       9 . The security article of  claim 8  wherein the substrate is composed of a plastic material.  
   
   
       10 . The security article of  claim 9 , wherein the plastic material is selected from the group consisting of polyethylene terephthalate, polycarbonate, polyvinyl chloride, polyacrylates, polyacrylonitrile, polystyrene, polypropylene, polynaphthalene terephthalate, and mixtures or copolymers thereof.  
   
   
       11 . The security article of  claim 8 , wherein the optical interference pattern is a diffraction grating pattern or a holographic image pattern.  
   
   
       12 . The security article of  claim 8 , wherein the color shifting optical coating is a multilayer optical interference film including an absorber layer on first or second surface of the substrate, and a dielectric layer on the absorber layer.  
   
   
       13 . The security article of  claim 8 , wherein the color shifting optical coating is a multilayer optical interference film including an absorber layer on the first or second surface of the substrate, a dielectric layer on the absorber layer, and a reflector layer on the dielectric layer.  
   
   
       14 . The security article of  claim 8 , wherein the color shifting optical coating is a multilayer optical interference film including an absorber layer, a dielectric layer, and a reflector layer; and wherein the reflector layer is the segmented layer.  
   
   
       15 . The security article of  claim 8 , further comprising a release layer on the substrate.  
   
   
       16 . A security article as claimed in  claim 8   wherein the interference pattern includes a diffraction grating pattern or a holographic image pattern wherein the colour shifting optical coating includes a color shifting multilayer optical film comprising: 
 an absorber layer on the first or second surface of the substrate;  
 a dielectric layer on the absorber layer; and  
 a reflector layer on the dielectric layer; and,  
   wherein the optical film coating provides an observable color shift as the angle of incident light or viewing angle changes.    
   
   
       17 . A security article as defined in  claim 16 , wherein the reflector layer is a segmented layer.  
   
   
       18 . A security article as defined in  claim 8  wherein the color shifting coating is on the second surface of the substrate and wherein the segmented layer is a reflector layer.  
   
   
       19 . A security article as defined in  claim 8  wherein the color shifting coating is on the first surface of the substrate and wherein the segmented layer is a reflector layer.  
   
   
       20 . A security article comprising: a light transmissive substrate having a first surface and an opposing second surface, said first surface having a diffraction grating pattern or a holographic image pattern formed thereon; and a color-shifting multilayer optical film structure formed on said diffraction grating pattern or said holographic image pattern formed on said first surface of said light transmissive substrate, so as to conform to the shape thereof, said color-shifting multilayer optical film structure being defined by an optical absorber layer formed directly on said diffraction grating pattern or said holographic image pattern formed on said first surface of said light transmissive substrate, a dielectric layer formed directly on said optical absorber layer, and a reflector layer formed directly on said dielectric layer said reflector layer replicating said diffraction pattern or said holographic image pattern formed on said first surface of said light transmissive substrate; wherein said color-shifting multilayer optical film structure provides color shifting with change of viewing angle or angle of incident light; and wherein the reflector layer is segmented forming a layer having blocking opaque regions and non-blocking windowed regions.  
   
   
       21 . A security article as defined in  claim 20 , wherein the non-blocking windowed regions provide no color shifting with a change of viewing angle or incident light.