Disk with substrate of alumina silicate resin glass
US4908727A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 8, 1988 |
| Grant date | Mar 13, 1990 |
| Priority date | — |
| Expiry date | Nov 8, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S428/90
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A vertical recording system using a rigid disk medium with high recording density has a substrate made of alumina silicate resin glass and a vertical magnetic anisotropic film located on said substrate. Said anisotropic film has an easy axis of magnetization in the thickness direction of the film, and the hard axis of magnetization in the film plane. The maximum surface roughness R.sub.max of said disk is less than 50 .ANG., and a magnetic recording head which moves relative to the medium operates with said head contacted with the medium. A recording density higher than 200 KFRPI (kilo flux reversal per inch) is obtained by the present invention.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.