Device for controlling rotation of a magnet used in a magneto-optical recording system
US4972337A · kind A · utility
11Cited by
3References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1987 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Dec 11, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/1056
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A rotation control for a magnet used in a magneto-optical recording system having a first coil that rotates a permanent magnet to invert the polarity of its magnetic field applied to an optical recording type disc and a second coil provided at the position displaced from the central line of the first coil and for applying a driving force to the permanent magnet when the permanent magnet begins to rotate, wherein the permanent magnet can be settled in quite a short time after it is inverted in polarity by controlling a drive current applied to the second coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.