Speaker device with a magnetic gap filled with magnetic fluid and changing magnetic flux density in axial and circumferential directions
US9462392B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2014 |
| Grant date | Oct 4, 2016 |
| Priority date | — |
| Expiry date | Dec 30, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R9/027
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A speaker device including a magnet formed in a ring shape; a yoke having a center pole portion inserted in the center of the magnet; a plate formed in a ring shape and arranged on an outer circumferential surface of the center pole portion of the yoke while being attached to the magnet; a coil bobbin formed in a cylindrical shape and movable in the axial direction of the center pole portion while being partially fitted on the center pole portion of the yoke; a voice coil wrapped around the outer circumferential surface of the coil bobbin, at least part of the voice coil being arranged in a magnetic gap formed between the plate and the center pole portion of the yoke; a diaphragm having its inner circumferential portion connected to the coil bobbin; and a magnetic fluid filled in the magnetic gap.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.