Abstract: Apparatus for forming a uniform film on a planar surface of a planar support, particularly for forming thermoplastic films on conductive support members, comprises a drivable turntable having means for removably locating the planar support and having a distributor, mounted for rotation with it, a housing enclosing the turntable and the support, and a dispenser, located in the housing for delivering a charge of fluent material to the distributor. The distributor is arranged to distribute fluent material radially outwardly onto the planar surface of the planar support, and has at least one portion extending axially from the turntable. The dispensing means is located with its outlet over the distributor.

Abstract: This invention concerns a method of recording wide-band signals on a thermoplastic film. The signal to be recorded is converted to an intensity modulation of a beam of electrons which is directed at the surface of a thin thermoplastic film carried on a conductive substrate. The film is rotated in its own plane and simultaneously translated so that the beam scans the film in a track which follows a spiral path. The deposition of charge produces after heating of the film a spatial modulation of the film. The intensity of the beam and the beam's impingement on the film is controlled in order that the charge pattern is appropriate for the formation of a spiral groove which is substantially invariant in cross-section but varies in depth along its direction of progression in accordance with the signal that modulates the intensity of the beam of electrons. The recording thus made can be used for the production of video discs capable of mechanical playback.

Abstract: A method of recording information on a thin film of thermoplastics material over a generally circular recording area, comprises the steps of directing a focussed, modulated beam of electrons on the film and simultaneously moving the film so that the beam deposits a track of charge which follows a spiral path, the film being carried by a support which has a conductive part in contact with the film, wherein the film is heated by the passage of an electric current through the conductive part of the support, the current being circumferentially uniform over the recording area. Preferably the information is recorded over an annular recording area between two spaced concentric conductive annular members in contact with the conductive part of the support, between which members the current is passed.

Abstract: This invention concerns a method of recording wide-band signals on a thermoplastic film. The signal to be recorded is converted to an intensity modulation of a beam of electrons which is directed at the surface of a thin thermoplastic film carried on a conductive substrate. The film is rotated in its own plane and simultaneously translated so that the beam scans the film in a track which follows a spiral path. The deposition of charge produces after heating of the film a spatial modulation of the film. The intensity of the beam and the beam's impingement on the film is controlled in order that the charge pattern is appropriate for the formation of a spiral groove which is substantially invariant in cross-section but varies in depth along its direction of progression in accordance with the signal that modulates the intensity of the beam of electrons. The recording thus made can be used for the production of video discs capable of mechanical playback.