Delay clock track read back data to compensate time variance due to disk thermal expansion in spiral servo track writing
US7253985B1 · kind B1 · utility
8Cited by
1References
23Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 6, 2006 |
| Grant date | Aug 7, 2007 |
| Priority date | — |
| Expiry date | Mar 6, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59661
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for writing servo information onto a disk of a hard disk drive with a servo writer. The disk has a circumferential index and a band of servo reference tracks. The circumferential index is detected from a clock signal generated from a clock track of the disk. The reference tracks include radial indices. A spiral servo pattern is written upon the detection of the circumferential index and a radial index. The servo writer includes a phase detector that detects changes in the relative position of the circumferential and radial indices and a delay circuit that delays the clock signal to offset such changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.