Drive control circuit for vibration speaker
US9319777B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 2011 |
| Grant date | Apr 19, 2016 |
| Priority date | — |
| Expiry date | Nov 1, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2400/01
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A drive signal generating unit generates a drive signal having a cyclic waveform containing a zero period in a vibration mode. A driver unit generates the drive current in response to the drive signal generated by the drive signal generating unit so as to supply the drive current to a voice coil. An induced voltage detector detects the induced voltage occurring in the voice coil during a nonconducting period. A zero-cross detector detects the zero cross of the induced voltage detected by the induced voltage detector. The drive signal generating unit estimates the eigen-frequency of a vibration speaker from a detected position of the zero cross and brings the frequency of the drive signal close to the estimated eigen-frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.