Capacitance detection control circuit for positioning a magnetic head close to a magneto-optical disk
US5095470A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1990 |
| Grant date | Mar 10, 1992 |
| Priority date | — |
| Expiry date | Aug 21, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B21/21
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetic head position control apparatus for driving the magnetic head of a disk recording apparatus toward or away from the recording surface of a magneto-optical disk to effect position control of the magnetic head. Changes in the distance between the magnetic head and the magneto-optical disk are detected from changes in capacitance between a capacitance detection electrode mounted on the magnetic head and a surface of the magneto-optical disk. An oscillator circuit connected to the capacitance detection electrode varies its oscillation frequency in response to changes in capacitance and detects such frequency variations and controls the position of the magnetic head for maintaining it at a constant predetermined distance from the magneto-optical disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.