Apparatus for generating magnetic field varying in response to an information signal
US5111441A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1991 |
| Grant date | May 5, 1992 |
| Priority date | — |
| Expiry date | Feb 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10576
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for generating a magnetic field varying in response to an information signal, which comprises a base plate made of electrical insulating material, a magnetic core mounted on one of opposite surfaces of the base plate, the magnetic core having a central leg portion extending through a hole formed in the base plate so as to cause its end face to appear on the other of the opposite surfaces of the base plate, a coil member wound on the central leg portion of the magnetic core to be supplied with a current varying in response to the information signal, and a capacitance detecting electrode formed with a thin conductive layer mounted on the other of the opposite surfaces of the base plate to be opposite to a recording medium having a conductive layer, the capacitance detecting electrode being provided with a cutout for restraining eddy current loss caused in the capacitance detecting electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.