Transducer head flying height monitoring methods and apparatus for disk drive system
US5168413A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1990 |
| Grant date | Dec 1, 1992 |
| Priority date | — |
| Expiry date | Nov 30, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/10055
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for measuring flying height changes of a transducer head relative to a disk surface of a rotating disk in a disk file. A predetermined pattern is written on at least one predetermined region of the disk file. The predetermined region is normally not rewritten during operation of the disk file. At least one readback signal is sensed from at least one predetermined region of the disk surface. A plurality of sample values are identified corresponding to each readback signal. A change in the flying height is calculated utilizing the identified sample values. A frequency equalization number K can be utilized to calculate the magnitude and sign of the flying height change. Alternatively, real-time digital analysis of a predetermined pattern written on at least one predetermined region of the disk surface can be utilized to calculate the magnitude and sign of the flying height change.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.