Process for direct over-writing of digital data recorded on magneto-optical recording media
US4679180A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1986 |
| Grant date | Jul 7, 1987 |
| Priority date | — |
| Expiry date | Mar 7, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2220/2525
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Methods for directly over-writing the binary data value of a bit of digital data, stored in a particular one of a multiplicity of microscopic storage regions of a thin-film magneto-optic recording layer, first locate the storage region and non-destructively read the stored data value therefrom, and then compare the recovered value against the data value of an information bit to be stored in the same storage region. If the comparison indicates that no change in the stored data value is required, then the process proceeds to read and compare the next bit of data, from the next associated storage location. If the comparison indicates that a reversal of the magnetic moment of that region is required to store the new data value, a source of energy is energized to heat the particular storage region of a sufficiently high temperature that the self-demagnetization field of the recording layer material inverts the net magnetic moment of that region. Multiple over-writing of the long-term stable stored data values can be provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.