Electro-acoustic transducer
US4504703A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 1984 |
| Grant date | Mar 12, 1985 |
| Priority date | — |
| Expiry date | Aug 16, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04R1/22
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An electro-acoustic transducer capable of operating as an emitter and as a pick-up for acoustic waves in an ambient medium includes a cover member having an opening for communication with the ambient medium, first and second diaphragms which are spaced from each other within the cover member, the second diaphragm being capable of vibrating under the effect of acoustic waves and being disposed between the first diaphragm and the opening in the cover member, an electromagnet for causing vibrations of the first diaphragm in response to electrical excitation signals when the transducer is operating in the emitter mode, an air cushion contained in a closed chamber separating the two diaphragms or a rigid mechanical connection between the two diaphragms for communicating the vibrations of the first diaphragm to the second diaphragm, and a pair of electrodes disposed on opposite sides of the second diaphragm, which is preferably a sheet of electret, for producing an output signal in response to vibrations of the second diaphragm produced by acoustic waves which are propagated in the ambient medium when the transducer is operating in the pick-up mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.