| 摘要 |
PURPOSE:To obtain the thinner-type speaker by providing a square-type center pole whose square-type plate is wound by an excitation coil, and an excitation part which is made of a square-rod-shaped permanent magnet of a coil outer circumference, and by holding a diaphragm by a suspension which is installed on the opposite side of the coil for the permanent magnet. CONSTITUTION:A square-type center pole 14 is combined with a square-type plate 15 as one unit or mechanically, and a square-shaped excitation coil 16 is wound around the pole 14. A square-rod-shaped permanent magnet 17 is arranged at two sides each which are opposed each other at the outer circumference part of the coil 16 on the plate 15, and according to the above, the excitation part is constituted. A suspension 18 is arranged on the opposite side of the coil 16 for the magnet 17, and between a square-shaped diaphragm 19 and the plate 15, the diaphragm 19 is arranged so that it will the prescribed interval on the excitation part. The suspension 18 provides a flat part 20 at the contact surface with which the suspension 18 and the plate 15 contact, and it is bent against the diaphragm 19. A flat part 21 is provided also at the contact face between the suspension 18 and the diaphragm 19, and the flat faces are fixed by screws 22-24. In this way, the thinner electromagnetic speaker can be obtained. |
