Error recovery in a disk drive
US6490691B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1999 |
| Grant date | Dec 3, 2002 |
| Priority date | — |
| Expiry date | Nov 24, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disk drive with the ability to detect errors caused by thermal asperities and assign alternate sectors is described. One of a plurality of error recovery procedures is executed after turning off a signal filter which normally removes a set of low frequencies from the output signal from the head. The unfiltered signal is used to judge whether a thermal asperity caused the error. If it is determined that a thermal asperity caused the error, the sector is marked as defective and an alternate sector is assigned even if other error recovery procedures are able to read the sector. The reliability of the drive is enhanced by removal of sectors from use which have temporarily recoverable errors caused by thermal asperities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.