Method and apparatus for hydrodynamic magnetic recording
US4633351A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 1985 |
| Grant date | Dec 30, 1986 |
| Priority date | — |
| Expiry date | Aug 7, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B23/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Problems of wear and bounce created by imperfections in the surface of a magnetic recording medium, such as a chromium dioxide-coated drum, are circumvented by a hydrodynamic magnetographic imaging technique that provides the intended effective intimate contact between the recording head the magnetographic recording surface. A readily evaporatable liquid (e.g. water, alcohol, acetone) is applied to the surface of the drum slightly upstream of the location of the recording head, so as to create a liquid bearing against which the recording head is urged, and thereby intimately magnetically coupled with the surface of the drum, except for an extremely thin liquid film between the head and drum surface. As a result of this extremely thin liquid bearing, continuous pressure can be applied to the head to maintain the head in effective intimate contact with the surface of the recording medium without the fear of scratching the medium or causing wear on the head. Moreover, once the imaging process has been completed, and the recording head is retracted away from the drum (and the liquid bearing) the liquid bearing can be easily removed, as the liquid of which the bearing if formed, readily…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.