Single-pass self-servowriting method and system employing a low sector rate startup procedure
US7405897B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 2006 |
| Grant date | Jul 29, 2008 |
| Priority date | — |
| Expiry date | Feb 14, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59644
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A self-servowriting (SSW) method that, with the actuator fully engaged against a compliant structure (e.g., a crashstop), first writes a tightly-spaced open-loop sequence of servo bursts in a segmented spiral path and then continues writing this tightly-spaced sequence under closed-loop servo control while reading back amplitude information from the servo bursts written earlier until the tightly-spaced burst pattern extends over several read-write head (RWH) offset intervals. With the actuator still engaged against the compliant structure, this tightly-spaced startup sequence is then read back by the closed servo control loop to write a number of concentric servo seed tracks, which are then self-propagated across the remainder of the disk surface to produce a final servopattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.