Magnetic head employing hard axis thin film inductor
US4136371A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 21, 1977 |
| Grant date | Jan 23, 1979 |
| Priority date | — |
| Expiry date | Sep 21, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/33
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A flux-sensitive magnetic head employs, at its back part, a structure having a thin single domain magnetic film coated thereon. A coil wraps around the coated structure, and a direct current is passed through the coil, thereby to apply a hard axis magnetic bias to the film. Signal flux appearing at the head front gap asserts a magnetic force along the hard axis of the film. Contrary to what would be expected, the signal flux causes the inductance of the coil to vary. Such inductance variation may be conveniently detected by (1) connecting the variable inductor into a tank circuit, (2) applying a high frequency ac ripple to the "hard axis" dc bias, and (3) measuring the "hard axis" detuning experienced by the tank circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.