(19)
(11) EP 1 526 758 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
29.03.2006 Bulletin 2006/13

(43) Date of publication A2:
27.04.2005 Bulletin 2005/17

(21) Application number: 03024363.8

(22) Date of filing: 24.10.2003
(51) International Patent Classification (IPC): 
H04S 3/00(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR
Designated Extension States:
AL LT LV MK

(71) Applicant: IAtec Limited
Taipei (TW)

(72) Inventors:
  • Hsu, Chen-Hua
    Taoyuan (TW)
  • Huang, Hsuan-Wei
    Keelung (TW)

(74) Representative: Viering, Jentschura & Partner 
Steinsdorfstrasse 6
80538 München
80538 München (DE)

   


(54) A 5.1 channel signal output mixer circuit for earphone


(57) A 5.1 channel signal output mixer circuit for earphone using step gain amplification unit comprising a filtering gain unit, a mixing gain unit and a noise reduction gain unit, wherein said filtering gain unit obtaining a bandwidth-adjusted subwoofer signal from two waveform shaping circuits, said mixing gain mixing said subwoofer signal with an output signal of a front channel to form a first signal, said noise reduction gain receiving said first signal for noise removal to form a signal and outputting said signal to a speaker.







Search report