EP 0751696 A1 19970102 - Equalization system of a telephone piezoceramic transducer
Title (en)
Equalization system of a telephone piezoceramic transducer
Title (de)
Entzerrungssystem für einen piezokeramischen Fernsprechwandler
Title (fr)
Système d'égalisation pour un transducteur piézocéramique téléphonique
Publication
Application
Priority
IT MI951380 A 19950628
Abstract (en)
The improvement consists in providing an acoustic filter capable of generating an acoustic resistance which is precise and stable. Such a filter is realized by providing the surface of the transducer bottom base, on which the piezoceramic circular diaphragm abuts, with channels of very small section. By varying the number and section of the channels it is possible to obtain the required precise and repetitive acoustic resistance as well as a response curve in function of the frequency which is sufficiently linear and suitable for the requirements in the telephone field. <IMAGE> <IMAGE>
IPC 1-7
IPC 8 full level
H04R 1/22 (2006.01); H04R 17/00 (2006.01)
CPC (source: EP)
H04R 1/225 (2013.01); H04R 17/00 (2013.01)
Citation (search report)
- [YDA] EP 0613323 A1 19940831 - ALCATEL DIAL FACE SPA [IT]
- [Y] DE 3618967 A1 19871210 - HAGENUK TELECOM GMBH [DE]
- [A] DE 2852176 A1 19800619 - TELEFONBAU & NORMALZEIT GMBH
- [A] US 4379212 A 19830405 - MARTIN ERWIN [DE]
Designated contracting state (EPC)
BE CH DE DK ES FR GB GR LI LU NL SE
DOCDB simple family (publication)
EP 0751696 A1 19970102; IT 1277195 B1 19971105; IT MI951380 A0 19950628; IT MI951380 A1 19961228
DOCDB simple family (application)
EP 96109137 A 19960607; IT MI951380 A 19950628