Abstract: A speaker device including a magnet formed in a ring shape; a yoke having a center pole portion inserted in the center of the magnet; a plate formed in a ring shape and arranged on an outer circumferential surface of the center pole portion of the yoke while being attached to the magnet; a coil bobbin formed in a cylindrical shape and movable in the axial direction of the center pole portion while being partially fitted on the center pole portion of the yoke; a voice coil wrapped around the outer circumferential surface of the coil bobbin, at least part of the voice coil being arranged in a magnetic gap formed between the plate and the center pole portion of the yoke; a diaphragm having its inner circumferential portion connected to the coil bobbin; and a magnetic fluid filled in the magnetic gap.

Abstract: A speaker device including a magnet formed in a ring shape; a yoke having a center pole portion inserted in the center of the magnet; a plate formed in a ring shape and arranged on the outer circumferential surface of the center pole portion of the yoke while being attached to the magnet; a coil bobbin formed in a cylindrical shape and movable in the axial direction of the center pole portion while being partially fitted on the center pole portion of the yoke; a voice coil wrapped around the outer circumferential surface of the coil bobbin, at least part of the voice coil being arranged in a magnetic gap formed between the plate and the center pole portion of the yoke; a diaphragm having its inner circumferential portion connected to the coil bobbin, the diaphragm being vibrated as the coil bobbin moves; and a magnetic fluid filled in the magnetic gap.

Abstract: A speaker includes a ring-shaped magnet, a yoke having a center pole portion inserted in the center of the magnet, and a ring-shaped plate and arranged on the outer circumferential surface of the center pole portion of the yoke and attached to the magnet. The speaker includes a cylindrically-shaped coil bobbin that is movable in the axial direction of the center pole portion and partially fitted on the center pole portion of the yoke. The speaker includes a voice coil wrapped around the outer circumferential surface of the coil bobbin, part of the voice coil being arranged in a magnetic gap, which is filled with a magnetic fluid, formed between the plate and the center pole portion of the yoke. The speaker includes a diaphragm having its inner circumferential portion connected to the coil bobbin, and that is vibrated as the coil bobbin moves.

Abstract: A speaker includes a ring-shaped magnet, a yoke having a center pole portion inserted in the center of the magnet, and a ring-shaped plate and arranged on the outer circumferential surface of the center pole portion of the yoke and attached to the magnet. The speaker includes a cylindrically-shaped coil bobbin that is movable in the axial direction of the center pole portion and partially fitted on the center pole portion of the yoke. The speaker includes a voice coil wrapped around the outer circumferential surface of the coil bobbin, part of the voice coil being arranged in a magnetic gap, which is filled with a magnetic fluid, formed between the plate and the center pole portion of the yoke. The speaker includes a diaphragm having its inner circumferential portion connected to the coil bobbin, and that is vibrated as the coil bobbin moves.