Servo control system using a varying frequency servo pattern for read/write head positioning in a magnetic recording disk file
US4589037A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1985 |
| Grant date | May 13, 1986 |
| Priority date | — |
| Expiry date | Mar 18, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59627
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved magnetic recording disk drive, in particular a flexible disk drive, includes a head positioning servo system which utilizes servo information recorded on the disk by the disk drive. The servo information is located within one of the data sectors and is in the form of a pattern of radially spaced-apart segments, each segment overlapping a number of data tracks and comprising magnetic transitions which increase in frequency in the radial direction to provide a digital head position error signal (PES). A similar segment is located in each of the other data sectors around the perimeter of the disk to provide track profile information so that the head positioning system can compensate for disk runout and distortion. The disk drive includes means for eliminating the effect of the amplitude of the readback signal from the servo and profile segments on the head positioning system, thus assuring a reliable PES at all radial locations on the disk and allowing interchangeability of disks among disk drives.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.