Glass substrate for a magnetic disk, a magnetic disk which can be formed with a stable texture and a magnetic disk device
US6801397B2 · kind B2 · utility
9Cited by
4References
15Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2003 |
| Grant date | Oct 5, 2004 |
| Priority date | — |
| Expiry date | Apr 8, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/82
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A glass substrate for a magnetic disk contains a transition metal. The substrate, which is subjected to formation of zone texturing by irradiating the substrate with a laser beam, has a high mechanical strength even if it is not chemically strengthened. The glass substrate contains a transition metal element and has a transmittance of 10% or less for light in a wavelength range of 300 to 2000 nm. The surface roughness of an information recording surface portion thereof is 2.0 nm or less. In addition to a transition metal element, the glass substrate may include a rare earth metal element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.