Abstract: Capacitive electronic discs having thin conductive layers are prepared by coating a core disc with a finely particulate conductive composition comprising a thermoplastic resin, conductive carbon black particles and suitable additives. The powder coating is compressed under heat and pressure to fuse the powder to the surface of the core disc. An information pattern is embossed therein, preferably simultaneously.

Abstract: Thin, flexible capacitive electronic discs are formed by directly compression molding a powder composition having a particle size such that no particles are larger than about 400 micrometers and a substantial portion is between about 25 and 300 micrometers and comprising a thermoplastic resin, conductive carbon black particles and suitable additives. An information track is embossed into at least one surface of the disc, preferably simultaneously with the molding step. The discs are from about 0.15 to 0.6 mm thick. Preferably, the discs are about 0.2 mm thick, which is about one-tenth of the thickness of present commercial discs.

Abstract: Apparatus for continuously reading out the graphic information represented by a charge pattern on a dielectric film includes an integrated circuit array of field effect devices each having a source and drain in series with a respective p-n junction photodiodes. A bias voltage is connected across the field effect devices and respective photodiodes and a load impedance. A scanner positioned to scan a spot of light over the array of photodiodes causes conduction of currents through field effect devices which are rendered conductive by charges on the dielectric film to produce a video signal across the load impedance.

Abstract: The method of, and apparatus for, producing an electrical video signal representing a charge pattern on an insulating dielectric sheet or film, without destroying the charge pattern, including the steps of: placing a transparent electrode on the free top surface of the dielectric film, placing the dielectric film having the charge pattern in close contact with the free top surface of an uncharged photoconductor having a back electrode connected to a load impedance, and scanning the photoconductor through said transparent electrode and said dielectric film with a flying spot of light to produce a video electrical signal across the load impedance during the scanning.