Permanent magnet device for selectively inverting a magnetic bias field for magneto-optic recording
US5535181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1995 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | Apr 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/1056
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for selectively inverting an external magnetic field in a magneto-optic recording system so that information can be selectively recorded on or erased from a magneto-optic recording element of the system moving through the field, the apparatus comprises a permanent magnet including a first and second portion positioned adjacent to each other and each portion having north and south poles oriented along their cross-sectional dimension, wherein the north pole of the first portion is abuttingly adjacent to the south pole of the second portion, and the south pole of the first portion is abuttingly adjacent the north pole of the second portion; and a coil for imparting a magnetic field to the permanent magnet for moving the permanent magnet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.