Thomson-Brandt

Thomson-Csf

Gerard Robin

Claude Bricot

Francois Le Carvennec

Robert Antoine

An apparatus 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 thermosettable 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 apparatus may also include a mechanisms for piercing the central hole and cutting out the disc. The formation of a succession of discs on the same film may be automatically obtained, the film advancing step by step between each moulding and/or cutting out operation.

Apparatus for making video discs

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.

Process for making video discs

The device of the invention allows a flexible substrate to be applied against the etched matrix with insertion therebetween of a layer of resin, the application of the substrate on the matrix taking place from the center progressively towards the periphery. It comprises support means in the form of a ring cooperating with a deformable resilient cushion of a convex shape so as to give a curved shape to the substrate at the beginning of molding then to effect the progressive application, while ensuring relative centering of the substrate and the matrix.

Device for molding information-carrying disks

The process according to the invention uses a matrix engraved by any means, the tracks being perfectly centered on this matrix in relation to a center of rotation. The matrix is placed in a vacuum chamber on a supporting axis capable of rotating and is coated over its entire surface with a polymerizable material which is free from air bubbles and which does not adhere to the constituent material of the matrix. A substrate previously drilled at its center, balanced and coated with a material to which the polymerizable material adheres, is placed on the supporting shaft and held at a distance from the matrix. The vacuum is established in the chamber and the substrate is brought into contact with the matrix. On completion of polymerization outside or inside the chamber, the substrate carrying the moulded resin is readily separated from the matrix.

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Paris, France

Gerard Robin