(19)
(11) EP 0 448 110 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
02.12.1992 Bulletin 1992/49

(43) Date of publication A2:
25.09.1991 Bulletin 1991/39

(21) Application number: 91104475.8

(22) Date of filing: 21.03.1991
(51) International Patent Classification (IPC)5: G10K 11/16, H04R 1/10
(84) Designated Contracting States:
DE GB

(30) Priority: 23.03.1990 JP 73814/90

(71) Applicant: SHARP KABUSHIKI KAISHA
Osaka 545 (JP)

(72) Inventor:
  • Suzuki, Akihisa
    Higashihiroshima-shi, Hiroshima-ken (JP)

(74) Representative: TER MEER - MÜLLER - STEINMEISTER & PARTNER 
Mauerkircherstrasse 45
81679 München
81679 München (DE)


(56) References cited: : 
   
       


    (54) Headphone apparatus


    (57) An inner-ear type headphone apparatus includes a diaphragm (2), a driving portion (3), a case (1), a duct (19), and a sound-absorbing portion (20). The driving portion (3) drives the diaphragm (2). A diaphragm backside space (15a) is formed between the diaphragm (2) and the driving portion (3). The driving portion (3) is attached to the case (1). The duct (19) conducts the diaphragm backside space (15a) to the external space outside the case (1). The sound-absorbing portion (20) communicates with the duct (19). The sound-absorbing portion (20) absorbs sound of high frequency range emitted to the external space outside the case (1) through the duct (19). The amount of unpleasant high frequency range sound leaking outside is reduced.






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