Patent · US Expired

Mechanical record cutting method

US4248438A · kind A · utility

4Cited by

7References

4Claims

0Family size

Assignee

TELDEC Telefunken-Decca Schallplatten GmbH · DE

Inventors

Herbert Knothe · Neumünster, DE
Horst Redlich · Berlin, DE
Klaus Roschmann · Uznach, CH

Key dates

Filing date	Mar 19, 1979
Grant date	Feb 3, 1981
Priority date	—
Expiry date	Mar 19, 1999

Classification

Technology area (CPC G)Physics
CPC primaryG11B3/44
WIPO fieldAudio-visual technology
WIPO sectorElectrical engineering

Abstract

In an apparatus for forming a groove which is modulated to present an information track in a signal record carrier having a copper surface portion by cutting such groove into the copper surface portion by means of a cutting stylus, the stylus is formed to present, during cutting, a rake angle of between 10.degree. and 20.degree., and the copper constituting the surface portion into which the groove is cut has a Vickers hardness of between 110 and 300, and preferably between 120-220.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.