Zone density sector counter
US4999720A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1989 |
| Grant date | Mar 12, 1991 |
| Priority date | — |
| Expiry date | Jun 5, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2020/1284
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In the present invention, a single sector counter and accompanying multiple buffer registers are used to provide the sector count for a plurality of recording zones. Initially, the sector counter is validated by synchronizing it with an index mark. In one embodiment, an angular position sensing counter counts a clock having a frequency and phase to match the occurrence of segments in a reference zone. A look up table or computation provides an offset value representing the difference between each reference zone segment boundary, and the occurrence of the next consecutive sector in each of the recording zones. Additional logic generates periodic sector pulses once the zone transition has been accomplished, and provides means to prevent generation of shortened sector intervals. This permits rapid validation of the sector signal so that it is no longer necessary to wait for the index in a hard-sectored drive before establishing the sector position when changing zones. This improves the latency of the disk drive and overall system performance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.