Hoechst Aktiengesellschaft

Ted Bildplatten Aktiengesellschaft, Aeg-telefunken, Teldec

Ted Bildplatten Aktiengesellschaft

Aeg-telefunken-teldec

Heinz Borchard

Herbert Knothe

Bruno Rybka

Rainer Mucke

Hans-Joachim Andrascheck

Peter Thun

Robert Kasch

Werner Lorz

Jurgen Buck

Gunter Grottker

A rigid polyvinyl chloride foil with modified impact resistance and free from plasticizer especially suitable for the manufacture of audio-visual information carriers with stamped spiral grooves from which the information is played back by pressure scanning. The foil is characterized by a special combination of properties such as flow, reduction in length, toughness, surface resistance, elasticity, peak-to-valley height and surface deposit.

Plastics foil for the manufacture of audio-visual information carriers

In the production of disc recordings, the label portion therefor is formed by tracing a pattern of essentially circular grooves or arrays of dots and groove or dot-free areas in the location of the label portion, the grooved areas contrasting visually with the groove-free areas and the pattern being such that one type of area, preferably the groove-free areas, forms the legible characters and patterns to appear in the label portion.

Disc recording provided with legible matter

A grinding foil which is to be used for grinding a record cutting or playback stylus is manufactured by providing a surface layer of a plastic foil with indentations for accommodating a grinding agent in granular form, filling the indentations with such grinding agent, and thermoplastically deforming the surface layer to smooth the foil surface and to bond the grinding agent into the surface layer.

Method for producing a grinding foil

Growing community of inventors

Nortorf, Germany

Heinz Borchard