EP 1221824 A4 20051207 - LOUDSPEAKER DEVICE
Title (en)
LOUDSPEAKER DEVICE
Title (de)
LAUTSPRECHERVORRICHTUNG
Title (fr)
DISPOSITIF A HAUT-PARLEUR
Publication
Application
Priority
JP 0005271 W 20000807
Abstract (en)
[origin: EP1221824A1] A loudspeaker device for use in various sound apparatus such as a television receiver, having an acoustic pipe disposed in front of a speaker unit, the acoustic pipe being provided with a microphone for detecting sounds reproduced by the speaker unit. The sounds reproduced by the speaker unit are corrected by the signals detected by the microphone to provide flattened sound output characteristics. The speaker device comprises a power amplifier (13) to which an input signal is delivered via a subtracter (6), a speaker unit (1) for reproducing output signals delivered from the power amplifier (13), an acoustic pipe (2) coupled in front of the speaker unit (1) for guiding the sound waves, a microphone (4) for detecting an acoustic outputs radiated from the speaker unit (1), and a microphone amplifier (5) for amplifying an acoustic output signals detected by the microphone (4). Output signals of the microphone amplifier (5) are delivered to the subtracter (6), at the same time the same output signal is connected to a high-pass filter (7) to be delivered to the subtracter (6). Thus a negative feedback circuit is formed to suppress peaks and dips for providing a flattened sound pressure frequency characteristic. <IMAGE>
IPC 1-7
IPC 8 full level
H04R 1/02 (2006.01); H04R 3/00 (2006.01); H04R 3/04 (2006.01)
CPC (source: EP)
H04R 3/002 (2013.01)
Citation (search report)
- [A] EP 0951201 A2 19991020 - MATSUSHITA ELECTRIC IND CO LTD [JP]
- [A] PATENT ABSTRACTS OF JAPAN vol. 1995, no. 09 31 October 1995 (1995-10-31)
- [A] PATENT ABSTRACTS OF JAPAN vol. 008, no. 206 (E - 267) 20 September 1984 (1984-09-20)
- See references of WO 0213573A1
Designated contracting state (EPC)
AT BE CH DE FR GB LI
DOCDB simple family (publication)
EP 1221824 A1 20020710; EP 1221824 A4 20051207; EP 1221824 B1 20061025; CN 1186965 C 20050126; CN 1377566 A 20021030; CZ 20021168 A3 20030212; CZ 299745 B6 20081112; DE 60031558 D1 20061207; DE 60031558 T2 20070606; HK 1049940 A1 20030530; HK 1049940 B 20050610; WO 0213573 A1 20020214
DOCDB simple family (application)
EP 00950015 A 20000807; CN 00813849 A 20000807; CZ 20021168 A 20000807; DE 60031558 T 20000807; HK 03101884 A 20030314; JP 0005271 W 20000807