Information recording disc demagnetization apparatus
US6058078A · kind A · utility
Inventor
Key dates
| Filing date | Dec 11, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Dec 11, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B11/10526
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An information recording disc demagnetization apparatus according to the present invention demagnetizes information recording discs whose information is read by irradiating a laser beam, such as a music CD (audio compact disc), a photographic CD, DVD, MD, etc. The demagnetization process performed by the apparatus of the present invention successfully recovers tone quality, image quality, and the like, of the information recording disc, all of which are deteriorated by magnetism attained by the disc during reproduction of the disc. The information recording disc demagnetization apparatus has a disc-shaped air-core coil for creating an alternating magnetic field having a decremental intensity, and a means for holding the information recording disc in a stationary state within the alternating magnetic field.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.