Servo control system using servo pattern time of flight for read/write head positioning in a magnetic recording system
US4598327A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 28, 1985 |
| Grant date | Jul 1, 1986 |
| Priority date | — |
| Expiry date | Jun 28, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59633
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved servo control system for data track following of the read/write head in a magnetic recording system uses a pattern of segments of servo information slanted across the data tracks. The time of flight of the servo segment from occurrence of a reference pulse until the peak servo signal is read by the head is an indication of the position of the head in a direction perpendicular to the desired track. This time is compared with the known time of flight if the head were precisely over the centerline of the desired track and the time difference is used to generate a control signal to position the head over the track centerline. In an embodiment where each segment is slanted across only one track, the reference pulse is the beginning of the servo signal and the time measurement is the number of fixed frequency magnetic transitions read by the head in the servo segment. When the system is used in flexible disk drives, the servo segments are written in one of the data sectors on the flexible disk by the user's disk drive.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.