Method and apparatus for testing MR head instability using a criterion that removes normal head fluctuation from consideration
US6519108B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1999 |
| Grant date | Feb 11, 2003 |
| Priority date | — |
| Expiry date | Dec 1, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/18
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for detecting disk drive head instability. Normal head fluctuation is removed from the criterion used to detect whether a head is unstable. The present invention accumulates error signals in an accumulator and calculates a criterion having an average fluctuation removed using the accumulated error signals. The criterion is calculated according to (max+min)−(2×average), wherein max is the maximum error signal, min is the minimum error signal and average is the average error signal. The criterion is then compared to a predetermine threshold to determine whether the head is unstable. A head is determined to be unstable when (max+min)−(2×average) is greater than the predetermined threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.