Capacitive position sensing for transducers
US9681228B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 6, 2015 |
| Grant date | Jun 13, 2017 |
| Priority date | — |
| Expiry date | Apr 6, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2499/11
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A micro speaker having a capacitive sensor to sense a motion of a speaker diaphragm, is disclosed. More particularly, embodiments of the micro speaker include a conductive surface of a diaphragm facing conductive surfaces of several capacitive plate sections across a gap. The diaphragm may be configured to emit sound forward away from a magnet of the micro speaker, and the capacitive plate sections may be supported on the magnet behind the diaphragm. In an embodiment, the gap provides an available travel for the diaphragm, which may be only a few millimeters. A sensing circuit may sense capacitances of the conductive surfaces to limit displacement of the diaphragm to within the available travel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.