Patent · US Expired

Electret transducer with variably charged electret foil

US4429191A · kind A · utility

5Cited by
5References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 20, 1981
Grant dateJan 31, 1984
Priority date
Expiry dateNov 20, 2001

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T29/49226
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

An electret transducer for producting a highly directional response characteristic comprises a backplate (18) and, superimposed thereon, an electrostatically charged electret foil (10). The electrostatic charge varies according to a predetermined relationship. The sensitivity of the electret transducer, at any point thereon, is directly proportional to the electrostatic charge on the electret foil at that point.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.