Sample data position error signal detection for digital sector servo
US5301072A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 4, 1993 |
| Grant date | Apr 5, 1994 |
| Priority date | — |
| Expiry date | Jan 4, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59622
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A sample data position error signal detection means is described. This invention is suited for use in a digital sector servo in a magnetic media disk drive environment. In particular, the invention relates to the detection and presentation in digital form of position error signals (PES) representative of magnitude and sign of recording head displacement from a track centerline. The circuits disclosed provide a digital representation of PES suitable for direct application to a digital signal processor which controls overall servo positioning operations. The invention detects the PES by an integration method and incorporates the innovation of requiring only two integrators to demodulate a PES having an arbitrarily large number of phases. The invention uses a phaselock oscillator having a hybrid digital/analog phase detector to generate the coherent carrier sequence for synchronous detection of PES. A further innovation of the invention is the use of a fully digital automatic gain control circuit (AGC). Prior embodiments of position demodulators have employed analog AGC approaches which are more sensitive to disk surface flaws and which cannot easily be made adaptive. Furthermore, suc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.