EP 0966178 A3 20010321 - Digital electro-acoustic transducer
Title (en)
Digital electro-acoustic transducer
Title (de)
Digitaler elektroakustischer Wandler
Title (fr)
Transducteur électroacoustique digital
Publication
Application
Priority
JP 17186598 A 19980618
Abstract (en)
[origin: EP0966178A2] A digital electro-acoustic transducer for improving the speech quality of sound under noisy circumstances is disclosed. A plurality of sound generating units A (22) constituted by electrostatic electro-acoustic transducers (condenser earphones) and a sound receiving unit B (23) constituted by an electrostatic acousto-electric transducer (condenser microphone) are disposed in a cavity of a soundproof housing (21). The units A (22) are provided in a feedback loop and an output level of the unit B (23) is adjusted by an preamplifier (24). An output of the preamplifier is sampled by a sample-and-hold circuit (25) and an output thereof is delta-modulated by a delta modulation circuit (26). The number of pulses produced by the circuit (26) is subjected to arithmetic operation in an arithmetic circuit (27) to produce a drive signal for the units A. Vibration of a vibration film of the unit B (23) is detected and arithmetical control is made to be always maintained to zero. On the other hand, an audio signal supplied from a signal terminal (28) is superposed on a drive signal for the units A and is emitted into the cavity. <IMAGE>
IPC 1-7
IPC 8 full level
H04M 1/00 (2006.01); H04R 1/00 (2006.01); H04R 17/00 (2006.01); H04R 5/033 (2006.01)
CPC (source: EP)
H04R 1/005 (2013.01); H04R 19/00 (2013.01); H04R 5/033 (2013.01)
Citation (search report)
- [Y] US 4922542 A 19900501 - SAPIEJEWSKI ROMAN [US]
- [Y] WO 9736454 A1 19971002 - NEUMANN GMBH GEORG [DE], et al
- [A] US 4370523 A 19830125 - BAEDER KARL O [DE]
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
EP 0966178 A2 19991222; EP 0966178 A3 20010321; EP 0966178 B1 20040526; CN 1173599 C 20041027; CN 1241107 A 20000112; DE 69917531 D1 20040701; DE 69917531 T2 20050804; JP 2000013890 A 20000114; JP 3553375 B2 20040811
DOCDB simple family (application)
EP 99304612 A 19990614; CN 99108651 A 19990618; DE 69917531 T 19990614; JP 17186598 A 19980618