Patent Document ID: 4615619
Application ID: 06613711
Patent Flag: 1

Claim One:
1. An electrically alterable masking device, comprising: substrate means adapted to remain fixedly positioned during use of said device, said substrate means presenting a pair of opposed faces and being relatively transmissive to radiations of selected wavelengths; a plurality of solid, electrically conductive masking structures supported in fixed positions upon one face of said substrate means and being electrically insulated from each other; and connector means electrically coupled with each of said masking structures respectively for connection of said respective structures with a source of electrical current for passage of electrical current through said masking structures as desired, each of said masking structures being formed of a crystalline dichromatic material which can be selectively altered between a condition where it is relatively transmissive for said radiations, and a condition where it is substantially opaque and relatively reflective for said radiations, by changing the magnitude of electrical current passing through the structure.