Method and apparatus for detecting and monitoring a bi-state head when self-servowriting a disk drive using spiral servo information
US7193797B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2005 |
| Grant date | Mar 20, 2007 |
| Priority date | — |
| Expiry date | Apr 8, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1282
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention is directed to a method and apparatus for detecting and monitoring a bi-state head when self-servowriting a disk drive. In one embodiment, an integration window is opened about an expected time that a read head will read spiral servo information. An integration value associated with the integration window is determined. Next, a determination is made as to whether the integration value is less than a predetermined low amplitude limit. If it is, a comparison is made between a location of a maximum sync frame of a read signal envelope in the integration window and the center of the integration window. The read head is identified as a bi-state head if the location of the maximum sync frame is greater than a predetermined off-center limit relative to the location of the center of the integration window.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.