Citizen Electronics Co., Ltd.

Toshio Itakura

Atsushi Kuwabara

Akira Yoneyama

An electroacoustic transducer has a magnetic circuit unit including a plate-shaped yoke, first and second magnets juxtaposed on the yoke, and first and second top plates mounted on the respective tops of the first and second magnets. One end of the first magnet is magnetized to one of north and south poles. The other end of the first magnet is opposite in polarity to the one end. The second magnet is magnetized to polarities opposite to those of the first magnet. A magnetic gap is formed between the first and second top plates.

Electroacoustic transducer and magnetic circuit unit

An electromagnetic exciter includes a first suspension having a cylindrical side wall portion coaxial with respect to a cylindrical wall of a yoke of a magnetic circuit assembly, and a spring portion integrally formed at the lower end of the cylindrical side wall portion to support the lower end of the magnetic circuit assembly so that the magnetic circuit assembly is vibratable. An annular support member is secured to the inner peripheral surface of the upper end opening of the cylindrical side wall portion of the first suspension. A printed wiring board that supports a voice coil is supported on the annular support member. A protector has a cylindrical portion installed to cover the outer peripheral surface of the cylindrical side wall portion of the first suspension, and a caulking portion that is bent radially inward over the upper end edge of the cylindrical side wall portion of the first suspension to clamp the printed wiring board between itself and the annular support member.

Electromagnetic exciter

A vibrating assembly comprises a yoke having a center pole and a peripheral flange, an annular permanent magnet secured to the flange, and an annular top plate secured to the permanent magnet. A supporting plate is provided for resiliently supporting the vibrating assembly in the frame. A preventing means is provided for preventing the vibrating assembly from moving in a radial direction of the vibrating assembly.

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Tsuru, Japan

Toshio Itakura