Spherical membrane omnidirectional loudspeaker using a magnetostrictive bimetallic strip

摘要

The invention concerns an omnidirectional loudspeaker. This loudspeaker comprises a spherical membrane which includes spires formed of a strip (2) made of a magnetostrictive material, the spires being spiral wound according to a sphere; these spires are kept in place by an elastic support (1) so that, along with the support, they form a spherical membrane. The strip has two opposing faces (11, 12), one of which is directed towards the inside (I) of the sphere, the other being directed towards the outside (E) of the sphere, and two extremities (3, 4) situated in two diametrically opposing zones of the sphere so as to be connected to an electric control device (5) providing a signal corresponding to sound waves to be reproduced, and a device (7) for the continuous polarization of the membrane. According to the invention, one of the faces (11) of the strip (2) is at least partly coated with a thin coating (13) made of a rigid material. Invention may be applied for the diffusion of high quality omnidirectional sound waves.