Magnetic recording medium having servo and data track regions with different arithmetical mean deviations
US7423842B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 2005 |
| Grant date | Sep 9, 2008 |
| Priority date | — |
| Expiry date | Oct 9, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/855
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic recording medium including at least a disk substrate 1A, a magnetic recording layer 5 formed with a predetermined concavo-convex pattern on the disk substrate 1A, and a non-magnetic layer 6 filled into concave portions of the concavo-convex pattern, so as to have data track regions 20 and servo pattern regions 21. Due to the existence of concaves and convexes in the surface of each data track region 20, the foregoing problem is solved. On this occasion, arithmetical mean deviation of the assessed profile Ra of the surface of each data track region 20 is preferably not lower than 0.3 nm. The difference in surface level between each concave and each convex existing in the surface of the data track region 20 is preferably not larger than 6 nm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.