Patent · US Expired

Electret transducer with variable electret foil thickness

US4429192A · kind A · utility

9Cited by
3References
10Claims
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 acoustic transducer for producing highly directional characteristics comprises a metalized backplate (130) facing the flat surface (134) of an electrostatically charged electret foil (132). The thickness of the electret foil varies along the length thereof according to a predetermined relationship. The sensitivity of the electret transducer varies directly with the thickness of the electret foil.

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