Method and apparatus for head positioning using spiral servo patterns in a disk drive
US7855850B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 2008 |
| Grant date | Dec 21, 2010 |
| Priority date | — |
| Expiry date | Apr 9, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59688
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
According to one embodiment, a disk drive having a disk, a read head, a servo controller, and a CPU. In the disk, a multi-spiral servo pattern is recorded. The read head reproduces a hexagon-shaped detection signal from the multi-spiral servo pattern. The servo controller generates amplitudes values for respective frames, from the multi-spiral servo pattern. The CPU performs positional-error calculation by using the amplitude values for the frames. Upon detecting a positional change of the head is detected, the CPU performs the positional-error calculation by using the amplitude values generated at the time of replacing the frames with other frames, and corrects the positional error by adding an offset determined from the positional change of the head, to the result of the positional-error calculation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.