still for framstellning of a dielktrisk beleggning on the surface of a conductive videoskiva

摘要

1417792 Video disc record for capacitive playback RCA CORPORATION 13 April 1973 [19 April 1972] 17794/73 Heading G4R A video disc record for the capacitive playback arrangement described in Specification 1,392,201 to 1,392,206 comprises a vinyl base in which the video information is stored as geometric variations in the base of a spiral groove, covered in a film of conducting, e.g. metal material and then coated with a layer of polymeric dielectric material. The disc record with its metal film is mounted in a vacuum chamber spaced from a similar size metal disc, the chamber is evacuated and a monomer, e.g. styrene, and a carrier gas, e.g. argon, are introduced at low pressure. A voltage is applied across the discs to produce a glow discharge at which the monomer polymerizes on the discs. The current is cut off when the polymer layer, in this case polystyrene, is of sufficient thickness.