Foster Electric Company, Limited

Hideo Koreeda

Yuichi Sakamoto

Takuro Yamaguchi

Yoshio Koike

Fumihiko Yamaguchi

A speaker system functioning as a stand capable of power supply to a mobile phone and hand-free communication and being capable of derived surround reproduction or stereo reproduction is provided. An enclosure (), on which a mobile phone is placed, includes therein supply means () for supplying electric power to the mobile phone, communication means () for enabling hand-free communication by the mobile phone through a microphone (), processing means for introducing signals from the mobile phone and performing a predetermined processing, and a pair of speakers (') provided on both sides of the enclosure in a state in which back sides thereof are substantially face to each other for generating sounds based on output signals from the processing means.

Speaker system

A diaphragm of electroacoustic transducer has an edge formed with alternately up-rolled and down-rolled portions with respect to vibration plane of the diaphragm and disposed at regular intervals in circumferential direction and with sloped-plane portions respectively connecting rims opposing above and below of adjacent ones of the up-rolled and down-rolled portions, the sloped-plane portions extending in respective tangential lines with respect to an inner periphery of the edge and intersecting the circumferential direction at an alternately opposite angle with respect to the vibration plane. The up-rolled and down-rolled portions of the edge provide an uneven shape varying in the stiffness of the portions upon vibration so as to cancel any difference in vibratory driving force from coils in a magnetic circuit, and any unbalanced vibratory driving force to the diaphragm due to magnetic flux distribution can be restrained by the uneven shape of the edge, so as to attain optimum rigidity of the diaphragm while rendering it to be well adaptable to dimensional minimization and thickness reduction.

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Tokyo, Japan

Hideo Koreeda