Cermet interface for electro-optical devices

In an electro-optical device of the type having substrate means for providing spatially and temporally modulated voltage or current patterns, having electro-optical means for presenting a display controlled by said patterns, and having an interface comprising light blocking means and mirror means between said substrate means and said electro-optical display means, the improvement comprising:

• said light blocking means comprising a plurality of layers each formed by a pair of sequentially alternating films, the first of said films in each of said pairs comprising a homogeneous dielectric material and the second of said films in each of said pairs comprising a randomly dispersed plurality of islands of a metallic electrical conductor separated by said dielectric material, said islands being spaced sufficiently to minimize the lateral conductivity of said second films and said first dielectric films being thin enough to permit transverse conduction between metal islands in said second films of adjacent layers by electron tunneling through the intervening first dielectric film to render said interface anisotropically conductive, said interface being a good electrical conductor in the transverse direction normal to the plane of its layers and being a good electrical insulator laterally in any direction in the plane of its layers.