Metal plate

Abstract

The invention relates to a metal plate ( 1 ) for a coin ( 2 ), for a centre pill ( 3 ) of a coin ( 2 ) or for a ring ( 4 ) of a coin ( 2 ), where it is suggested that at least one subregion of a surface, on at least one side of the metal plate ( 1 ), has a dual-coloured optical element ( 5 ) and that said optical element ( 5 ) has at least one first region ( 6 ) with a first oxide layer ( 7 ) of one first colour which is an interference colour, and at least one second region ( 8 ) with a second colour, the first colour being different from the second colour.

What is claimed is: 
     
         1 - 19 . (canceled) 
     
     
         20 . A metal plate for a coin, for a centre pill of a coin or for a ring of a coin, said metal plate comprising:
 a dual-coloured optical element provided on at least one side of the metal plate on at least one subregion of a surface, said optical element having at least one first region and at least one second region, said at least one subregion of the surface of the metal plate having a height profile formed by minting, with the first region being formed as a depression of the height profile in relation to the second region;   a first oxide layer with a first colour applied on the first region of the optical element, said first colour being an interference colour, said second region having a second colour which is different from the first colour; and   a motif displayed in a congruent manner by both the minting of the height profile and the dual-coloured optical element.   
     
     
         21 . The metal plate of  claim 20 , wherein the first oxide layer is produced electrochemically, especially by anodic oxidation. 
     
     
         22 . The metal plate of  claim 20 , wherein the first oxide layer comprises an oxide of a material of the metal plate. 
     
     
         23 . The metal plate of  claim 20 , wherein the metal plate is made of a metal or a metal alloy of the group 4, 5 and/or 6 of the periodic system, especially Ti, Mo, and/or Nb. 
     
     
         24 . The metal plate of  claim 20 , further comprising a second oxide layer applied on the second region, said second colour being preferably an interference colour. 
     
     
         25 . The metal plate of  claim 24 , wherein the second oxide layer is produced electrochemically, especially by anodic oxidation. 
     
     
         26 . The metal plate of  claim 24 , wherein the first oxide layer has a thickness which is greater than a thickness of the second oxide layer. 
     
     
         27 . A coin, comprising a metal plate comprising a dual-coloured optical element provided on at least one side of the metal plate on at least one subregion of a surface, said optical element having at least one first region and at least one second region, said at least one subregion of the surface of the metal plate having a height profile formed by minting, with the first region being formed as a depression of the height profile in relation to the second region, a first oxide layer with a first colour applied on the first region of the optical element, said first colour being an interference colour, said second region having a second colour which is different from the first colour, and a motif displayed in a congruent manner by both the minting of the height profile and the dual-coloured optical element. 
     
     
         28 . A coin, comprising:
 a centre pill; and   a ring,   at least the centre pill being formed as a metal plate comprising a dual-coloured optical element provided on at least one side of the metal plate on at least one subregion of a surface, said optical element having at least one first region and at least one second region, said at least one subregion of the surface of the metal plate having a height profile formed by minting, with the first region being formed as a depression of the height profile in relation to the second region, a first oxide layer with a first colour applied on the first region of the optical element, said first colour being an interference colour, said second region having a second colour which is different from the first colour, and a motif displayed in a congruent manner by both the minting of the height profile and the dual-coloured optical element.   
     
     
         29 . A method, comprising:
 an oxide layer production step, in which an oxide layer having an interference colour is produced at least on a subregion of a surface of a metal plate, especially a coin, a centre pill of a coin, or a ring of a coin;   minting a height profile onto the at least one subregion of the surface of the metal plate such that at least one first region of the subregion of the surface is formed as a depression of the height profile in relation to at least a second region of the subregion of the surface; and   a surface modification step, in which the second region of the subregion of the surface is modified through an abrasive process for achieving different optical properties between the second region and the first region of the subregion of the surface to thereby produce a dual-coloured optical element, with a motif being displayed in a congruent manner by both minting of the height profile and by the optical element.   
     
     
         30 . The method of  claim 29 , further comprising roughening, especially pickling, prior to the surface modification step, at least the one subregion of the surface of the metal plate. 
     
     
         31 . The method of  claim 29 , wherein the surface modification step is carried out before the oxide layer production step. 
     
     
         32 . The method of  claim 29 , wherein the oxide layer production step is carried out before the surface modification step, and further comprising removing the oxide layer in the at least one second region in the surface modification step, while leaving the oxide layer in the at least one first region. 
     
     
         33 . The method of  claim 29 , wherein the abrasive process is implemented by a mechanical process, especially flat grinding and/or polishing off process. 
     
     
         34 . The method of  claim 29 , wherein an oxide of a material of the metal plate is produced as the oxide layer of the oxide layer production step. 
     
     
         35 . The method of  claim 29 , wherein the oxide layer of the oxide layer production step is produced by an electrochemical process, especially by oxidising the metal plate through anodic oxidation. 
     
     
         36 . The method of  claim 29 , further comprising producing, after the surface modification step, a further oxide layer on the at least one subregion of the surface of the metal plate. 
     
     
         37 . The method of  claim 36 , wherein the further oxide layer is produced in such a way that the first region has a first oxide layer with a first thickness, and the second region has a second oxide layer with a second thickness, with the first thickness being greater than the second thickness.