Positioning method and apparatus therefor
US4490662A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1983 |
| Grant date | Dec 25, 1984 |
| Priority date | — |
| Expiry date | Jul 27, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P8/32
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A positioning method and apparatus for precisely positioning a magnetic head on a desired track of a magnetic disc includes stepping motor having a plurality of stationary pole windings adapted to be rotated stepwise, and a mechanism for moving the magnetic head by a rotational movement of the stepping motor. By rotating the stepping motor stepwise by an integral multiple of the number of stationary pole windings of the stepping motor, the magnetic head is moved by one track width of the magnetic disc. By driving the stepping motor by the integral multiple of the number of stationary windings, the magnetic head is positioned by the same stationary pole windings without being affected by an assembling tolerance of the stationary pole windings. The stepping motor may also be driven so as to overrun a desired track by at least one step and then rotated in a reverse direction by the same number of steps so that a positioning error due to forward and reverse rotations of the stepping motor is eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.