Demagnetizer for a magnetic head of a recording-reproducing device
US4135219A · kind A · utility
17Cited by
9References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 20, 1977 |
| Grant date | Jan 16, 1979 |
| Priority date | — |
| Expiry date | Jul 20, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B23/04
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A demagnetizer for a magnetic head for a recording/reproducing device. The demagnetizer includes an electromagnet for producing an alternating magnetic field which gradually decreases in intensity. The demagnetizer is mounted in a case formed in the shape of a tape cassette. The electromagnet is resiliently held within the case adjacent to the opening for the magnetic head to be demagnetized. The electromagnet is energized by an oscillating drive circuit, the output of which is controlled by a capacitor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.