MAGNET CIRCUIT STRUCTURE FOR SPEAKER

PURPOSE:To make a speaker into a flat shape and to contrive the increase of magnet efficiency by using an integrated circular sintered magnet with anisotropy in a radial direction and sintering integrally the magnet with a yoke. CONSTITUTION:The yoke 1 is provided with a center pole 2, a flange part 43 formed from the bottom face toward an outer periphery, a stage 4a formed in an opposite direction to the center pole, and a stage part 4b formed at the outer periphery of the flange part, in the same direction as the center pole. The integrated circular sintered magnet 5 with the anisotropy in the radial direction is installed on the flange part 3 of the yoke, and its inner periphery is integrated with the outer periphery of the center pole part 2 by sintering, while its outer periphery is made larger than the above mentioned stage part 4a of the yoke so that a required gap space is formed to the stage part 4b. A voice coil 7 is installed at the gap space 6, thus, it is not necessary to use the yoke above the magnet, then the speaker can be made into the thin shape.