Head positioning system for a disc data store
US4524397A · kind A · utility
Inventors
Key dates
| Filing date | Jan 27, 1983 |
| Grant date | Jun 18, 1985 |
| Priority date | — |
| Expiry date | Jan 27, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/59677
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a disc data store, wherein a read/write head is radially positionable by a feedback servomechanism to interact with a selectable one out of a plurality of radially equispaced data storage tracks on a rotary disc, the positioning errors resultant from phase errors between the plural signals available as the output of an optical grating head position transducer are eliminated by replacing one of the data storage tracks with a servo track by arranging that the period of the recursive, triangular wave position indicating signals from the transducer is equal to twice the radial spacing between tracks on the disc, by selecting as the exclusively-used position indicating signal that one of the plurality of transducer signals which brings the head to the center of the servo track with least offset, and, while employing that selected signal or its generated inverse as the feedback signal to the servomechanism applying that least offset as a correction when positioning the head over data storage tracks.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.