Magnetic recording/reproducing method using a thin film magnetic
US5530609A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1994 |
| Grant date | Jun 25, 1996 |
| Priority date | — |
| Expiry date | May 31, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/74
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a method for magnetically recording and reproducing signals in and from a magnetic recording medium via a thin film magnetic head, the recording medium has a magnetic layer of up to 0.5 .mu.m thick containing hexagonal ferromagnetic particles on a non-magnetic substrate, and the magnetic head includes a recording head whose gap adjacent portion is formed of a soft magnetic material having a saturation magnetic flux density of at least 0.7 T and a reproducing MR head. In one form, the magnetic layer has a surface roughness (Ra) of up to 5 nm, and a coercivity (Hc) of at least 1,100 Oe and a squareness ratio (S) of at least 0.70. In another form, the magnetic layer contains hexagonal ferrite and has a squareness ratio (S.perp.) of at least 0.70, and the magnetic head produces a reproduction output which is subject to zero-crossing detection without passing through a differential circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.