Dual-mode loudspeaker
US8116508B2 · kind B2 · utility
13Cited by
4References
26Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 26, 2008 |
| Grant date | Feb 14, 2012 |
| Priority date | — |
| Expiry date | Oct 7, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R2499/11
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus uses a transducer to produce vibration in the ultrasonic frequency range and in the audible frequency range. A membrane or cantilever structure is coupled to the transducer to produce acoustic waves. When the vibration is in the audible frequency range, the membrane structure works like a conventional loudspeaker. When the vibration is in the ultrasonic frequency range, the ultrasonic signal is modulated by audio signal for creating better directivity. The acoustic waves in the ultrasonic frequency range can reproduce directional audible sound due to the nonlinear interaction of ultrasonic waves in air.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.