(19)
(11) EP 0 610 001 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
18.01.1995 Bulletin 1995/03

(43) Date of publication A2:
10.08.1994 Bulletin 1994/32

(21) Application number: 94300426.7

(22) Date of filing: 20.01.1994
(51) International Patent Classification (IPC)5: H04R 9/04, H04R 7/00
(84) Designated Contracting States:
DE FR GB

(30) Priority: 29.01.1993 JP 34330/93

(71) Applicant: SONY CORPORATION
Tokyo (JP)

(72) Inventors:
  • Kishigami, Jun, c/o Sony Corporation
    Tokyo (JP)
  • Uryu, Masaru, c/o Sony Corporation
    Tokyo (JP)

(74) Representative: Nicholls, Michael John 
J.A. KEMP & CO. 14, South Square Gray's Inn
London WC1R 5LX
London WC1R 5LX (GB)


(56) References cited: : 
   
       


    (54) Loudspeaker


    (57) A loudspeaker includes a diaphragm, a bobbin, a voice coil and a magnetic circuit. The diaphragm is formed of one of materials selected from paper, high molecular materials, metallic materials and cellulose. The bobbin is connected to the diaphragm and formed of cellulose produced by bacterial cultivation. The voice coil is wound on the bobbin. The magnetic circuit has a yoke, a plate and a permanent magnet and is arranged facing the voice coil. The loudspeaker has satisfactory acoustic properties and high fidelity in sound reproduction.






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