Variable format timing runout compensation
US6611391B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 28, 2000 |
| Grant date | Aug 26, 2003 |
| Priority date | — |
| Expiry date | Jan 1, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59627
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and system of identifying and compensating for the cumulative effect of once per revolution, OPR, timing errors by modulating the size of an inter-sector runout (ISR) field between servo sectors. The ISR field is part of an inter-sector gap (ISG) field. The method begins when the nominal data field frequency is increased by one-half of the spin speed tolerance to guarantee adequate data field tolerances at the fastest portion of the timing OPR error curve. The ISR field is added to the disc format and maintained as a rotationally varying field. The ISR field is varied rotationally from a minimum of zero to a maximum equal to the timing OPR error tolerance. The size of the ISR field is varied rotationally based upon a calibration table that is used to identify the location of the disc drive head and to compensate for the appropriate timing OPR error at that location. The remainder of the ISG field is used to compensate for fixed timing errors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.