Substrate Comprising A Fabry-Perot Filter And Method For Application Of The Filter To The Substrate

Abstract

A Fabry-Perot filter is applied as a thin coating on a film, for example, a packaging film, and permits interesting color effects. The coating has a layered construction in which both reflecting layers of the filter may be made of aluminum and the intermediate layer between the reflecting layers may be made of aluminum oxide.

1 - 11 . (canceled)  
   
   
       12 . A substrate having a Fabry-Perot filter applied comprising at least three layers, including a first and a second reflecting layer with mutually facing reflecting surfaces of the filter spaced apart by a gap of thickness d and enclosing a light-transmissible intermediate layer located in the gap, wherein the first and second reflecting layers comprise the same base material and the intermediate layer comprises a chemical compound of the base material and a further material.  
   
   
       13 . The substrate as claimed in  claim 12 , wherein the base material is a metal and the further material oxygen, such that the first and second reflecting layers comprise a metal and the intermediate layer comprises a metal oxide in stoichiometric or nonstoichiometric composition.  
   
   
       14 . The substrate as claimed in  claim 12 , wherein the metal is aluminum and the intermediate layer comprises aluminum oxide.  
   
   
       15 . The substrate as claimed in  claim 12 , wherein the base material is a metal and the further material nitrogen, such that the reflecting layers comprise a metal and the intermediate layer comprises a metal-nitrogen compound in stoichiometric or nonstoichiometric composition.  
   
   
       16 . The substrate as claimed in  claim 15 , wherein the metal is aluminum and the intermediate layer is therewith comprised of an aluminum nitride.  
   
   
       17 . A substrate as claimed in  claim 12 , wherein the first reflecting layer adjoins the substrate and is opaque to light and the outer second reflecting layer is partially transmissible to light.  
   
   
       18 . A substrate as claimed in  claim 17 , wherein the first reflecting layer adjoins the substrate and has a thickness between 10 and 200 nm, the second reflecting layer between 1 and 20 nm and the intermediate layer has a thickness between 50 and 2000 nm.  
   
   
       19 . A method for the application of a filter on a substrate comprising: 
 providing a vacuum coating facility with a vaporization device in an evacuatable vacuum chamber and a material supply device,    charging the vaporization device with the base material,    closing the vacuum chamber and generating a vacuum therein,    vaporizing the base material exclusively such that it is deposited as a first layer on a substrate,    vaporizing the base material with the simultaneous introduction of the further material into the vacuum chamber such that the substrate provided with the first layer is reactively vapor deposited with an intermediate layer of the base material and the further material,    vaporizing the base material exclusively such that it is deposited on the intermediate layer to form a second reflecting layer,    opening the coating chamber and removing the coated substrate.    
   
   
       20 . A method as claimed in  claim 19 , wherein the material supply device is a gas connection.  
   
   
       21 . A method as claimed in  claim 19 , wherein the substrate to be coated is a web sheeting which is unwound via a coating cylinder located above the vaporization device.  
   
   
       22 . A method as claimed in  claim 21 , wherein the vacuum chamber includes two stock rolls, the web for the vapor deposition of the discrete layers alternately wound from the one stock roll and wound onto the particular other.