Electret transducer with variable actual air gap
US4434327A · kind A · utility
14Cited by
5References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1981 |
| Grant date | Feb 28, 1984 |
| Priority date | — |
| Expiry date | Nov 20, 2001 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49226
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electret transducer for producing a directional response, electret foil (92) and a backplate (94) with the actual air gap thickness therebetween varying in accordance with a predetermined relationship. The sensitivity of the electret transducer varies inversely as the actual air gap thickness. In one embodiment the actual air gap thickness is realized by a plurality of posts (90) having heights varying according to the aforesaid relationship. In another embodiment, the actual air gap thickness is realized by varying the thickness of the aforesaid backplate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.