Matsushita Electric Industrial Co., Ltd.

Masakuni Hirata

Mitsukazu Kuze

Mitsutaka Enomoto

Takanori Fukuyama

Kazuro Takano

Yasuo Kodera

An electro-mechanical-audio converter and an electro-mechanical-audio converting device using the same employed in mobile terminals such as mobile phones for generating paging vibration which realizes stable vibration function. The electro-mechanical-audio converter includes a housing ( ), movable part ( ), forming a magnetic circuit, mounted on an opening of the housing ( ) through a suspension ( ); and a detection coil ( ) disposed near the movable part ( ) for generating excitation voltage by vibration of the movable part ( ). Strong vibration of the movable part ( ) during resonance is detected by the detection coil ( ) as an excitation voltage, and fed back. Accordingly, the electro-mechanical-audio converter and electro-mechanical-audio converting device using the same having an extremely stable vibration function, even when resonance frequency changes due to environmental changes such as ambient temperature, is made feasible.

Electrical/mechanical/sound converter and apparatus of electrical/mechanical/sound conversion

A diaphragm for a loud speaker is manufactured by impregnating a diaphragm blank made of natural or man-made fibers or formed by molding a synthetic resin, with a water-soluble inorganic flame retarder, and thereafter with an aqueous solution of a fluorine containing water repellent and oil repellent agent, and then by heating and molding into a speaker diaphragm.

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Osaka, Japan

Masakuni Hirata