Abstract: The invention relates to a transmission projection screen having a high light output and a suitable contrast, for example, for use in a projection-television system, and a method of manufacturing such a screen.The projection screen comprises a transparent substrate having a front surface which is provided with mutually parallel ribs. Light-absorbing glass fibers 10 are provided at the bottom of the grooves 24 between the ribs 22, and they are fixed by means of a hot-melt adhesive layer 11.

Abstract: In the optical connection of telecommuniation glass fibres to semiconductors a curable composition is used which comprises a polyester urethane acrylate or a polyether urethane acrylate. The composition furthermore comprises a heat- or light-activatable initiator.The refractive index of the cured connecting material is adjusted by the addition of both a reactive diluent which increases the refractive index and a reactive diluent which decreases the refractive index. Said reactive diluents furthermore serve to establish the desired mechanical properties of the connecting material prior to and after curing.The curable composition is provided on the glass fibres and/or on the semiconductor laser, after which they are contacted with each other and are optically aligned. The composition is then cured by raising the temperature or by exposure to light.

Abstract: Optical fibres consisting of a synthetic resin at least on their outer circumference are continuously provided with a metal coating by electroplating. For this purpose the synthetic resin coating is made electrically conductive, for example, by continuous electroless metallization.

Abstract: Optical recording disc having successively a transparent substrate plate, a first layer of a formstable synthetic resin comprising an optically readable information track, a second thin layer of a linearly polymerized amorphous synthetic resin and a recording layer in which optically readable information bits are formed by exposure to modulated laser light.

Abstract: Optical recording disc having a supporting plate of synthetic resin or being coated with a layer of synthetic resin, an ablative recording layer on the synthetic resin or the layer of synthetic resin and a phosphorus derivative having at least one organic radical in the interface of the synthetic resin or layer of synthetic resin on the side of the recording layer.

Abstract: Additive method of manufacturing metal patterns on synthetic resin substrates, printed circuits in particular. A nuclear image of a desired pattern is obtained by means of a salt of a metal which may occur in more than one valency and a noble metal salt by inactivating the substrate area outside the desired pattern by photo-oxidation by means of exposure to light in the presence of oxygen. The ultimate metal pattern is deposited by electroless metal deposition on the nuclear image.