Process for making video discs
AssigneeThomson-Brandt
InventorsClaude Bricot, Gerard Robin
Life of this patent
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Abstract
A process for making video discs by moulding from an engraved master which includes depositing on one edge of the master an elongated fillet of a curable resin; photopolymerizable or thermosetting and spreading gradually the resin between the master and a flexible film of a substrate which is applied by means of a pressure roller, the resin being then cured as required by ultra-violet or infrared radiation through the film. The process may also include piercing the central hole and cutting out the disc. The formation of a succession of discs on the same film may be made automatic, the film advancing step by step between each moulding and/or cutting out operation.
Claims10
A process for making at least a single faced video disc having an engraved zone carrying information in the form of surface micro-reliefs from at least one master utilizing a pressure roller and a flexible film of transparent substrate which comprises:
- positioning said film above said master;
- depositing a fillet of resin on said at least one master outside said engraved zone and below said film;
- advancing said roller in a direction perpendicular to said fillet of resin so as to contact said film with said fillet or resin to drive said fillet of resin in front of said roller and said film and to uniformly spred said fillet of resin between said at least one master and said film so as to form a layer of said resin on said film;
- retracting said roller from said engraved zone;
- removing said combined film and layer of resin from said at least one master;
- and
- curing said layer of resin so as to form said disc.
Dependencies are inferred from the claim text.