Using servowriter medium for quickly written servo-patterns on magnetic media
US5991104A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 27, 1996 |
| Grant date | Nov 23, 1999 |
| Priority date | — |
| Expiry date | Nov 27, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/865
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Servo-pattern information is magnetically recorded on a product disc by magnetic print-through from a master medium. The master servo-writing medium is brought into close proximity with the product "slave" disc, and the two are subjected to an external magnetic field which assists in transferring magnetic servo-patterns to the slave disc in a print-through process. The preferred external magnetic field alternates and rotates with respect to the master/slave combination. In an alternative product disc structure, the magnetic layer is magnetically altered in a servo-pattern configuration. Non-magnetic portions of the servo pattern are created which define both gray code and servo burst information for the product disc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.