Written-in repeatable run-out compensation in embedded servo disc drives
US6804079B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 12, 2001 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | Oct 29, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59627
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method of correcting for written-in repeatable run-out in a disc drive having a servo loop for positioning a head over a rotating disc is provided. The rotating disc has at least one data track and servo information recorded in a plurality of servo fields along the data track. An initial written-in repeatable run-out compensation value for each servo field is computed as a function of a position error signal generated for each servo field during a first revolution of the disc. The initial written-in repeatable run-out compensation value for each servo field is then injected into the servo loop during another revolution of the disc. A compensated position error signal for each servo field is computed as a function of the initial written-in repeatable run-out compensation value for each servo field. A refined written-in repeatable run-out compensation value for each servo field is then computed as a function of the compensated position error signal for each servo field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.