Magnetic damping disc for improved CD player performance
US5258972A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 25, 1990 |
| Grant date | Nov 2, 1993 |
| Priority date | — |
| Expiry date | Jun 25, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A disc (14,24) providing magnetic absorption and mechanical damping is provided which is for mounting near or upon the top of a Compact Disc (100) in position in a CD player. The disc includes one or more layers of material having high magnetic permeability, such as MuMetal. In a specific embodiment, a damping disc is formed of a pair of MuMetal layers on the order of 0.004 inch in thickness separated by a substantially rigid elastomer. The damping disc provides shielding and magnetic loading by absorbing magnetic fields of a player drive motor and arm servo motor to dissipate energy, thereby reducing magnetic field coupling with electronic signal components. The damping disc is mounted on top of a CD (100) and includes a magnetic shielding layer (12) and an acoustic damping layer (16).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.