Disc memory servo indexing system
US4956727A · kind A · utility
6Cited by
4References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1989 |
| Grant date | Sep 11, 1990 |
| Priority date | — |
| Expiry date | Feb 6, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59633
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A servo disc in a magnetic disc drive has pulses recorded in frames in concentric data tracks. Each frame includes first and second sync pulse groups of at least one sync pulse each, a first track alignment signal (Quad) following the first sync group, and a second track alignment signal (Sig) following the second sync group. A Guard Band and a data Track Zero are identified by eliminating one sync pulse in selected members of frames. Circuitry including monostable multivibrator, flip-flops, and gates identify the Guard Band and Track Zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.