Star Micronics Company Limited

Kazushi Suzuki

Yoshio Imahori

Kazushige Tajima

Takahiro Sone

Isao Fushimi

Mitsuhiro Masuda

Hiroshi Fujinami

Yoshiharu Oishi

Naoyuki Kigawa

Harunobu Tsuchiya

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 ( ) includes a diaphragm ( ) made of magnetic material and spaced from the forward end of the magnetic core; a magnet ( ); a coil ( ) wound around the magnetic core ( ) and supplying an oscillating magnetic field to the diaphragm; a support ring ( ) which supports the diaphragm ( ); a lower housing ( ) which accommodates members; an upper housing ( ) attached to the upper housing ( ). Coil spring-like terminals ( ) are attached to terminal accommodating portions ( Ga) which are opened in the bottom face of the lower housing ( ). Lead wires ( a) and ( b) of the coil ( ) are directly connected to the terminals ( ), respectively. The terminal accommodating portions ( a) are sealed by a soldering process.

In an electroacoustic transducer having an outer case integral with lead terminals and a drive section including a coil disposed in the outer case with both coil terminals of the coil being led out on and connected to lands of the lead terminals, the lands are formed in approximately circular shapes.

The invention provides a miniaturized and low-profile electroacoustic transducer. In the electroacoustic transducer, a space is formed underneath a magnet by diminishing a vertical thickness of the magnet in comparison with the height of a magnetic core, and also by disposing the magnet at a position trensversely aligned to an upper portion of the magnetic core, so that the space is utilized as a part of a back space at the back of a diaphragm, and for connection of terminals of a coil with external terminals, thereby realizing miniaturization and flattening in the shape of the electroacoustic transducer.

An electroacoustic transducer has lead terminals formed of an alloy consisting of 32 to 55% by weight of Ni and a remainder essentially of Fe, and having a crystal grain size of 7.0 or greater. In an electroacoustic transducer, both coil terminals of the coil are connected to the associated lands of the lead terminals, and thermal conduction suppressing sections are provided at proximal end sides of lands of the lead terminals for suppressing thermal conduction.

A method of ultrasonic welding for a resin case in which an ultrasonic vibration is applied to the resin case in a direction parallel to the welding surface.

Method of ultrasonic welding for a resin case

A terminal connection method of a coil comprises the steps of arranging coil terminals of a coil on lead terminals; removing insulating coats of the coil terminals to expose core wires; and applying an electric conductivity adhesive to connected portions of the coil terminals and the lead terminals. A terminal connection structure of a coil comprises coil terminals arranged on lead terminals, with insulating coats removed from the coil terminals; and an electric conductivity adhesive applied to connected portions of the coil terminals and the lead terminals.

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Shizuoka, Japan

Kazushi Suzuki