Particulate magnetic recording media having an areally controlled recording characteristics
US4805065A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1986 |
| Grant date | Feb 14, 1989 |
| Priority date | — |
| Expiry date | Oct 29, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/858
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Utilizing the technique whereby particulate media electrodeposited at a critical electric field intensity has a given packing density, and when electrodeposited at a lesser electric field intensity has a lower density, the present invention teaches electrodeposition of media whose particulate packing density varies in accordance with an areally predetermined pattern. The pattern is incised in one electrode of the deposition apparatus, and the medium as deposited on the other electrode mirrors the pattern as a varying particulate packing density. The packing density varies with the electric field intensity, and the electric field varies due to the unequal interelectrode distances arising from the incisions in the electrode. The medium is then d.c. magnetized, and the density variation provides a magnetically reproducible signal in accordance with the pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.