EP 0464222 A4 19921104 - SOUND REPRODUCING DEVICE
Title (en)
SOUND REPRODUCING DEVICE
Publication
Application
Priority
- JP 9100028 W 19910116
- JP 10007290 A 19900416
- JP 1145590 A 19900119
Abstract (en)
[origin: WO9111077A1] A sound reproducing device suitable for use with a headphone of the open-air type in noisy environment. The frequency band of sounds leaking out when the headphone is put on is measured in advance, and the leakage from the headphone is controlled by switching a filter for attenuating the leakage frequency band when the headphone is being put on. Moreover, noise frequency characteristics are measured in advance, a low frequency band is reinforced to correspond to the above characteristics, and operation of the filter is changed over to attenuate the high frequency band that includes the above sound leakage frequency band.
IPC 1-7
IPC 8 full level
H04R 3/04 (2006.01)
CPC (source: EP)
H04R 3/04 (2013.01)
Citation (search report)
- [A] EP 0130613 A2 19850109 - VICTOR COMPANY OF JAPAN [JP]
- [A] EP 0122663 A2 19841024 - FREADMAN TOMMYCA
- [A] PATENT ABSTRACTS OF JAPAN vol. 10, no. 75 (E-390)25 March 1986 & JP-A-60 223 284 ( FUJITSU ) 7 November 1985
- See references of WO 9111077A1
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
WO 9111077 A1 19910725; DE 69114772 D1 19960104; DE 69114772 T2 19960418; EP 0464222 A1 19920108; EP 0464222 A4 19921104; EP 0464222 B1 19951122
DOCDB simple family (application)
JP 9100028 W 19910116; DE 69114772 T 19910116; EP 91902758 A 19910116