| 摘要 |
<p>PURPOSE:To obtain a speaker having the nondirectivity in a horizontal direction, by connecting plural semicylindrical diaphragms at a fold part, mounting a mobile coil wound into a flat rectangle at the fold part and then setting the windings at the magnetic fields which are opposite and orthogonal to each other. CONSTITUTION:Plural semicylindrical diaphragms 1 are connected at a fold part 2 to form an oscillation cylinder 3 having a petal-shaped section. A mobile coil 4 formed into a flat and rectangle is mounted at the part 2 so that the longer side of the coil 4 is set in parallel to the part 2. Both the coil 4 and the cylinder 3 are attached to a frame 7 by means of a center damper 5 and a peripheral damper 6 so that they can oscillate in the radial direction. A permanent magnet 8 and a yoke 9 are assembled into a U-shaped and an adverse U- shape to form intensive magnetic fields opposite to each other and orthogonal to the winding of the coil 4. When an alternating current is flowed to the coil 4, the diaphragm 1 oscillates in the radial direction. And the coils 4 are set so as to generate the driving force of the same phase to each other. Thus the cylinder 3 is oscillated so as to be expanded and contracted in the radial direction. As a result, the sound waves are radiated evenly in the radial direction.</p> |
