Title:
SPEAKER
Document Type and Number:
Japanese Patent JP3137217
Kind Code:
B2
Abstract:
PURPOSE: To obtain high accuracy and high sound quality by installing a voice coil in a repulsive magnetic field formed by arranging two magnet disks and coupling a diaphragm to the voice coil so as to attain thin profile and light weight.
CONSTITUTION: Magnets 3, 4 are arranged by inserting a spacer 2 to a center of a bowl shaped frame 1 having a window 1a. The magnets 3, 4 are formed to be disks and magnetized in the thickness direction. The magnets 3, 4 are arranged in the 'direction of magnetism in which opposed faces are repulsive to each other and a repulsive magnetic field 5 is formed therearound. A voice coil 6 is placed in the repulsive magnetic field 5. The coil 6 is wound almost in the middle of the outer circumference of the voice coil bobbin provided in vibration enable way at the outer circumference of the magnets 3, 4. An inner circumferential part of the cone shaped diaphragm 8 is coupled in the middle of the outer circumference of the coil 6. An outer edge of the diaphragm 8 is connected to the outer circumferential part of the frame 1 via an edge 9. A sub-cone 10 is provided in the middle of the front side of the diaphragm 8 and a dust-proof center cap 11 is provided in the middle.
Inventors:
Rintaro Kohara
Ken Yoshimura
Hidetoshi Shirakawa
Ken Yoshimura
Hidetoshi Shirakawa
Application Number:
JP3932093A
Publication Date:
February 19, 2001
Filing Date:
February 03, 1993
Export Citation:
Assignee:
Foster Electric Co., Ltd.
International Classes:
H04R9/02; H04R9/04; H04R9/06; (IPC1-7): H04R9/04; H04R9/02; H04R9/06
Domestic Patent References:
| JP57395A | ||||
| JP59148500A |
Attorney, Agent or Firm:
Michio Takayama