Magnetic recording medium
US5906880A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1996 |
| Grant date | May 25, 1999 |
| Priority date | — |
| Expiry date | Apr 25, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/265
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium, comprising a nonmagnetic substrate on the surface of which is deposited a magnetic layer. In one embodiment, the magnetic layer is formed of two thin films of magnetic metal and a layer of nonmagnetic material sandwiched therebetween, the layer of nonmagnetic material having a thickness no greater than 20% of the thickness of the magnetic layer, with the magnetic layer having an energy product of at least 100 gauss.multidot.cm.multidot.Oe as the product of its residual magnetic flux density, thickness and coercive force, and a surface roughness no greater than 0.003 .mu.m in center line average height. In another embodiment, the magnetic layer, which may be a single layer of magnetic metal film or may be of the aforementioned multiple layer construction, is vacuum deposited onto the substrate at an incident angle in the range of 30.degree. to 70.degree..
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.