Method for reducing disk thermal expansion effects while writing reference spiral servo patterns to a disk of a disk drive
US6992852B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 2004 |
| Grant date | Jan 31, 2006 |
| Priority date | — |
| Expiry date | Oct 15, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59661
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for reducing disk expansion effects while writing spiral reference patterns on a disk of a disk drive. The disk drive comprises control circuitry and a head disk assembly (HDA) for positioning a head radially over the disk. In the method, an external spiral servo writer is used to control a radial location of the head for writing a plurality of the spiral reference patterns between inner and outer seed tracks. A head velocity profile is adjusted for writing each spiral reference pattern to account for thermal disk expansion. The head internal to the disk drive is used to read the spiral reference patterns in order to write product servo bursts to the disk that define a plurality of radially-spaced circular data tracks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.