High track density media with optical servo tracks and method and apparatus for inscribing the tracks on the media
US5120927A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1990 |
| Grant date | Jun 9, 1992 |
| Priority date | — |
| Expiry date | Jun 12, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59677
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic information storage medium, such as a floppy or rigid magnetic disk, and an apparatus and method for inscribing a plurality of indelible grooves in a surface of the medium to function as optical servo tracks. The grooves can be in the form of a plurality of continuous or noncontinuous concentric circles. The grooves can also be a continuous spiral or a plurality of continuous concentric circles having non-constant widths and/or depths. The apparatus comprises a platen and drive motor for rotating the medium, an argon ion laser light source for generating a beam of light, optical components for directing the beam of light to a beam focusing carriage and a microcomputer for controlling the apparatus. The method involves rotating the medium under the focused light beam to inscribe the grooves on the surface of the medium. Optical track densities greater than 1000 tracks per inch can be obtained with the method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.