Magnetic recording medium
US4649073A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 1985 |
| Grant date | Mar 10, 1987 |
| Priority date | — |
| Expiry date | Mar 6, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31678
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a magnetic recording disk of a double-sided recording type according to a perpendicular magnetic recording technique of the invention, recording layers having different film thicknesses are formed on two surfaces of a base layer. The film thickness of one magnetic recording layer is set to be larger than the film thickness of the other magnetic recording layer. Thus, a curl phenomenon can be prevented. In addition, a coercive force of the thicker recording layer is set to be higher than that of the thinner recording layer. A difference in a perpendicular recording density between the two recording layers due to a difference in the film thickness thereof can be compensated for.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.