Method and apparatus for minimizing once per revolution positional errors in single disc servo track writing
US6414814B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1999 |
| Grant date | Jul 2, 2002 |
| Priority date | — |
| Expiry date | Sep 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59633
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method for minimizing once per revolution (OPR) positional errors in a single disk servo track writer (STW) comprises clamping a disc having an outer edge in the servo track writer; spinning the disc in the servo track writer at a predetermined speed; measuring distance from the disc edge to a predetermined point to determine peak to peak once per revolution positional error; determining an average once per revolution positional error from the peak to peak once per revolution positional error; and setting a reference position for writing servo tracks on the disc equal to a predetermined track reference plus the average once per revolution positional error. The servo track writer apparatus comprises a spindle motor for supporting and rotating a disc and a distance sensor such as an interferometer mounted a preset distance from the edge of the disc for measuring the once per revolution outer diameter positional error.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.