Star Micronics Company Limited

Yoshiharu Oishi

Yoshio Imahori

Youichi Gotoh

Takahiro Sone

Mitsuhiro Masuda

Hiroshi Fujinami

Kazushi Suzuki

Yoshikazu Tsuchikiri

Kazuyasu Ono

Yoichi Gotoh

Harunobu Tsuchiya

Takao Katsuki

Susumu Tanikawa

Morimasa Fushimi

A core having a coil wound thereon is fixed to a base at the bottom. The base is fixed to a case made of synthetic resin by insert molding. A diaphragm is fixed to the case in circumference, and also a magnetic flux guide member is fixed to the case in circumference. Since the diaphragm and the magnetic flux guide member is commonly fixed to the case, no variation in the distance between the diaphragm and the magnetic flux guide member would occur for every product. Further, a gap L is formed between the magnet and the magnetic flux guide member, and an air hole is formed in the magnetic flux guide member. This improves the passage of air and reduces air dumper effect without modifying the magnet in shape.

Electroacoustic transducer

An electroacoustic transducer adapted to be mounted on a printed circuit board in which a coil spring is accommodated and supported in a cylindrical recess of a frame while it is fixed to neither a terminal plate nor the frame. Particularly, a protruding pin of the coil spring is passed through a though hole of the terminal plate to allow a leading portion of the protruding pin to be hooked thereon. When the electroacoustic transducer is mounted on the printed circuit board, any horizontal displacement between the compressed spring and the printed circuit board would not cause stress concentration on the coil spring since the coil spring is onlly horizontally shifted in the cylindrical recess until a coil portion of the coil spring hits against the wall of the cylindrical recess.

An electroacoustic transducer ( ) includes a base ( ) and magnetic core ( ) a diaphragm ( ) supported with a gap between the diaphragm and a forward end of the magnetic core, a magnet ( ) constituting a magnetic circuit together with the base ( ), the magnetic core ( ) and the diaphragm ( ) a coil ( ) disposed around the magnetic core a coil bobbin ( ) for holding the coil ( ), a housing ( ) for receiving the above-mentioned members, a filler ( ) applied to an external surface side of the base ( ), and lead terminals ( and ) for supplying an electric current. The lead terminals ( and ) have protrusion portions ( and , protruding into an internal surface side of the base ( ) in the axial direction of the coil. A coil wire ( ) is wound around the protrusion portions ( and ) so as to be connected to the lead terminals ( and ).

A pole piece is placed on a lower case A pole piece has a core and a base The bobbin portion extends from the lower case toward the internal space of a case so as to surround the outer periphery of the core The bobbin portion is divided into a plurality of portions along the circumferential direction of the core The bobbin portion has basal parts and elongated parts The pole piece is pressed from the above of the lower case in a state where the bobbin portion is passed through holes of the base to be positioned on the outer periphery of the core so that the pole piece is fitted and placed into the lower case A coil is configured by winding a conductor wire around the elongated parts of the bobbin portion

There is provided an electroacoustic transducer including a base made of magnetic material, a magnetic core made of magnetic material and provided erectly on the base a diaphragm made of magnetic material and supported with a gap between the diaphragm and a forward end of the magnetic core, a magnet constituting a magnetic circuit together with the base the magnetic core and the diaphragm so as to provide a magnetostatic field, a coil disposed around the magnetic core for applying an oscillating magnetic field to the magnetic circuit, a coil bobbin for holding the coil and a housing for receiving these above-mentioned members. The coil bobbin is integrally molded with the magnetic core and the base member

An electroacoustic transducer, which has a case, a base located in the case, a core attached to the center of the base, a coil wound around the core, a magnet placed around the coil with a clearance formed in between with one end of the magnet is supported by the base, a support member located around the magnet for supporting an elastic plate, and a magnet support portion provided in the support member for supporting the other end of the magnet.

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Shizuoka, Japan

Yoshiharu Oishi