Colored Coatings for Electronic Devices

Abstract

An electronic device may have transparent housing structures such as walls formed of glass or sapphire. Housing structures such as transparent housing structures may have a colored coating. The colored coating may include an absorptive layer and a metal layer. The coating may exhibit a color that can be adjusted by adjusting the thickness of the thin absorptive layer. A colored layer such as a layer of colored polymer may be incorporated into the colored coating to further adjust the color of the coating. The colored coating may be formed on an inner or outer housing structure surface. The surface may have a texture to provide the coating with a matte appearance. When formed on an outer surface, a diamond-like carbon layer may protect the colored coating. When formed on an inner surface, a passivation layer may be used to prevent oxidation of the metal layer.

What is claimed is: 
     
         1 . An electronic device having an interior and an exterior, comprising:
 a structure that is transparent to visible light, wherein the structure has an inner surface facing the interior; and   a coating on the inner surface, wherein the coating includes an amorphous semiconductor layer.   
     
     
         2 . The electronic device defined in  claim 1 , wherein the amorphous semiconductor layer comprises an amorphous silicon layer. 
     
     
         3 . The electronic device defined in  claim 1 , wherein the coating further comprises a metal layer, wherein the amorphous semiconductor layer is interposed between the metal layer and the inner surface. 
     
     
         4 . The electronic device defined in  claim 3 , wherein the coating further comprises a passivation layer on the metal layer. 
     
     
         5 . The electronic device defined in  claim 4 , wherein the passivation layer comprises amorphous silicon. 
     
     
         6 . The electronic device defined in  claim 1 , wherein the structure comprises glass. 
     
     
         7 . The electronic device defined in  claim 1 , wherein the structure comprises a housing wall and wherein the inner surface is textured. 
     
     
         8 . The electronic device defined in  claim 7 , wherein the inner surface has a surface roughness of 25 nm to 400 nm. 
     
     
         9 . The electronic device defined in  claim 7 , wherein the coating further comprises a protective layer on the metal layer. 
     
     
         10 . The electronic device defined in  claim 9 , wherein the protective layer comprises diamond-like carbon. 
     
     
         11 . An electronic device, comprising:
 a structure that is transparent to visible light; and   a colored coating on the structure, wherein the colored coating includes a metal layer and an amorphous semiconductor layer between the metal layer and the structure.   
     
     
         12 . The electronic device defined in  claim 11 , wherein the colored coating further comprises a colored polymer layer. 
     
     
         13 . The electronic device defined in  claim 12 , wherein the colored polymer layer comprises dye. 
     
     
         14 . The electronic device defined in  claim 12 , wherein the colored polymer layer is interposed between the structure and the amorphous semiconductor layer. 
     
     
         15 . The electronic device defined in  claim 12 , wherein the colored polymer layer is formed on the metal layer and wherein the metal layer is between the colored polymer layer and the amorphous semiconductor layer. 
     
     
         16 . An electronic device, comprising:
 a visible-light transparent structure; and   a coating on the visible-light transparent structure that includes an amorphous semiconductor layer and a layer comprising metal.   
     
     
         17 . The electronic device defined in  claim 16 , wherein the visible-light transparent structure has inner and outer surfaces, wherein the coating is on the inner surface. 
     
     
         18 . The electronic device defined in  claim 16 , wherein the amorphous semiconductor layer is interposed between the inner surface and the layer comprising metal. 
     
     
         19 . The electronic device defined in  claim 17 , wherein the layer comprising metal is between the amorphous semiconductor layer and the inner surface. 
     
     
         20 . The electronic device defined in  claim 16 , wherein the visible-light transparent structure has inner and outer surfaces and wherein the coating is on the outer surface.