Detecting a thermal asperity condition of a disk drive head responsive to data value transitions
US7483227B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 2006 |
| Grant date | Jan 27, 2009 |
| Priority date | — |
| Expiry date | Apr 21, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/40
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods are disclosed for detecting a thermal asperity condition of a head that is configured to generate a read signal by reading data on a rotatable data storage disk in a disk drive. The read signal includes a data component and a thermal component. The read signal is compared to a thermal asperity threshold to detect occurrence of an excessive level of the thermal component of the read signal as a thermal asperity condition of the head. The thermal asperity threshold is varied in response to a rate of occurrence of data value transitions in the data component of the read signal. The thermal asperity threshold can be increased in response to a decrease in the rate of occurrence of data value transitions, and can be decreased in response to an increase in the rate of occurrence of data value transitions. By varying the thermal asperity threshold, the sensitivity of the thermal asperity detector may be improved to allow lower level thermal asperity conditions to be detected with increased accuracy. Related disk drives are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.