Flying height measurement and control with user data signal
US7542227B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2007 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Jun 29, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/6029
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A hard disk drive that determines a flying height from a slope of a line created from a ratio of amplitudes of frequencies in response to impulse functions. A first set of amplitudes of reference frequencies can be determined from a reference impulse. A second set of amplitudes of data frequencies can be determined from a data impulse during operation of the disk drive. Ratios of amplitudes of the data and reference frequencies at different discrete frequencies can be plotted. The slope of the plotted line corresponds to the difference between the flying height when the reference impulse is generated and the flying height when the data impulse is generated. The disk drive may utilize the slope in a feedback routine to control the flying height.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.