Compensation of write current adn delta-V for recording component and radial position
US4821125A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1986 |
| Grant date | Apr 11, 1989 |
| Priority date | — |
| Expiry date | Jun 11, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/183
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic disk drive channel circuitry is shown and described that generates eight incremental values of write current and eight incremental values of delta-V (the minimum voltage change per unit time which tests signals to discriminate between data and noise). Each of these variable parameter values may be program selected by a three bit bus signal. This variability testing of an adaptation to the optimum parameter value for each head media combination and by grouping tracks in contiguous data bands, the parameters may be optimized for tracks near the inner diameter, the outer diameter and in the middle band. The variable delta-V can also be used as an additional data recovery tool wherein re-reading with a lower value enhances recovery of missing bit errors and re-reading with an increased value can assist recovery from an extra bit error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.