EP 0077615 A1 19830427 - Electret microphone shield.
Title (en)
Electret microphone shield.
Title (de)
Abschirmung für ein Elektret-Mikrophon.
Title (fr)
Ecran pour microphone à électrète.
Publication
Application
Priority
CA 388183 A 19811019
Abstract (en)
An electret microphone has a metal shield around it in order to guard against electromagnetic interference. Acoustic waves reach the electret element through a passage in the shield. The electret response is undesirably affected by an electric field produced by body capacitance when the microphone is brought close to a user;s mouth. To overcome this effect, the microphone has a conductive film, transparent to acoustic waves, positioned between the passage and the electret element, the film contacting a grounded part of the casing. The conductive film can form an integral part of a microphone moisture barrier.
IPC 1-7
IPC 8 full level
H04R 1/08 (2006.01); H04R 1/22 (2006.01); H04R 19/01 (2006.01); H04R 19/04 (2006.01)
CPC (source: EP KR)
H04R 1/08 (2013.01 - KR); H04R 19/016 (2013.01 - EP)
Citation (search report)
- [X] US 3942029 A 19760302 - KAWAKAMI HIROTAKE, et al
- [X] US 3778561 A 19731211 - REEDYK C
- [Y] US 3787642 A 19740122 - YOUNG R
- [A] US 4188513 A 19800212 - DRAGUNEVICIUS ALGIRDAS J [CA], et al
- [A] THE BELL SYSTEM JOURNAL, vol. 58, no. 7, September 1979, pages 1557-1577, New York (USA);
Designated contracting state (EPC)
CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0077615 A1 19830427; EP 0077615 B1 19860430; CA 1165859 A 19840417; DE 3270879 D1 19860605; DK 153619 B 19880801; DK 153619 C 19881219; DK 450682 A 19830420; IE 53590 B1 19881221; IE 822516 L 19830419; JP S5881000 A 19830516; KR 840002387 A 19840625; KR 880000963 B1 19880604
DOCDB simple family (application)
EP 82305196 A 19820930; CA 388183 A 19811019; DE 3270879 T 19820930; DK 450682 A 19821012; IE 251682 A 19821018; JP 18151682 A 19821018; KR 820004689 A 19821018