Apparatus and method for cutting information into a metallic record carrier
US4484320A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 7, 1982 |
| Grant date | Nov 20, 1984 |
| Priority date | — |
| Expiry date | Apr 7, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B3/72
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus for recording an information signal on a metallic record carrier. The information is impressed on the carrier by cutting a groove therein by means of a stylus, the groove being characterized at each point by a slope or modulation pitch angle. The stylus has a longitudinal axis, a leading edge substantially parallel to this axis and a trailing edge. The angle between the longitudinal axis of the stylus and a normal to the surface of the record carrier is greater than 10.degree. and not more than a value which would make the angle between the trailing edge of the stylus and the surface of the record carrier less than the maximum modulation pitch angle. The stylus is movably attached to a fixed structure by a mounting member and is electromagnetically excited by a driving member to shape the grooves in the record carrier in accordance with the information signal. The record carrier, stylus, mounting and driving members are dimensioned to generate an oscillation at a frequency which is higher than that of the information signal and superimpose this oscillation on the information signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.