Panasonic Corporation

Masashi Kawabe

Kazuki Honda

Koji Sano

Satoshi Itoh

Mamiko Tsutsumi

Mitsukazu Kuze

Hiroshi Yano

Masahide Sumiyama

Takeshi Shimokawatoko

Kazutaka Kubo

Takanori Fukuyama

Shigeru Tomoeda

Tomoyasu Takase

Toshiyuki Koike

Masanori Nakano

Takehiko Tanabu

In a loud speaker, the diaphragm has a protruded part protruding on a yoke side on the inside and in the vicinity of an inner coupling part as a coupled portion to a voice coil. The loud speaker can be manufactured with the voice coil accurately positioned with respect to a diaphragm, and the voice coil is accurately vibrated vertically inside a magnetic gap. The possibility of the voice coil coming into contact with a plate and a yoke as a magnetic circuit body of the loud speaker can be reduced, thereby to improve production efficiency and a yield at the time of manufacturing the loud speaker.

Loud speaker manufacturing method

A loudspeaker includes a first bar magnet having a longitudinal direction, a second bar magnet having a longitudinal direction parallel to the longitudinal direction of the first bar magnet, a third bar magnet forming a second magnetic gap between the first bar magnet and the third bar magnet, a diaphragm arranged to vibrate in a vibrating direction, a case accommodating the first bar magnet, the second bar magnet, the third bar magnet, and the diaphragm , and the voice coil fixed to the diaphragm and located in the first and second magnetic gaps. The second bar magnet has a longitudinal direction parallel to the longitudinal direction of the first bar magnet, and has both ends in the longitudinal direction. The third bar magnet has a longitudinal direction parallel to the longitudinal direction of the first bar magnet, and has both ends in the longitudinal direction. The diaphragm is located between the first and second bar magnets and between the first and third bar magnents. The case is made of non-magnetic material and holds an outer periphery of the diaphragm. The case forms a first space surrounded by the case, one of the both ends of the second bar magnet, and one of the both ends of the third bar magnet. The case forms a second space surrounded by the case, another one of both ends of the second bar magnet, and another one of both ends of the third bar magnet. First and second sound holes are provided in the case and communicate with the first and second spaces, respectively. The loudspeaker is thin but outputs large sounds.

Loudspeaker

In a loudspeaker, three magnets are disposed to provide magnetic gaps therebetween and a voice coil is fit therein. The magnets disposed at both sides are magnetized so that their opposing poles exhibit the same magnetic polarity. The magnet in the middle has its magnetic poles in the direction perpendicular to the line connecting the poles of the side magnets. The side magnets are fixed to a plate made of non-magnetic material. Those magnetic poles of the side magnets and the middle magnet not facing the magnetic gaps are magnetically coupled by a magnetic member.

Loudspeaker and electronic apparatus using the same

A net made of material containing at least metal is bonded to a protector of a loud speaker, and hence shields electromagnetic waves. Electromagnetic interference can be prevented in an electronic apparatus such as a portable phone employing the loud speaker.

Speaker, and module, electronic apparatus, and device that use the speaker

Growing community of inventors

Mie, Japan

Masashi Kawabe