Method and apparatus for reducing velocity errors when writing spiral servo information onto a disk surface
US7248427B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 2004 |
| Grant date | Jul 24, 2007 |
| Priority date | — |
| Expiry date | Dec 26, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59622
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to a method and apparatus for reducing velocity errors when writing spiral servo information onto a disk surface of a disk drive. In one embodiment, a servo track writer is provided for moving a write head at a controlled velocity. The write head is used to write spiral servo information onto a disk surface. The write head is moved, using the servo track writer, at an actual velocity trajectory to simulate writing one spiral of spiral servo information. Differences between the actual velocity trajectory and a desired velocity trajectory are measured on a control sample by control sample basis over a window of control samples. The differences are integrated over the window. A gain, associated with the servo track writer controlling the velocity of the write head, is adjusted using the integrated differences.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.