Patent ID: 8705789

Claim:
A magnet-less loudspeaker, comprising: a ferrite core ( 1 ) having a main surface and a lateral surface; a voice coil ( 2 ) wound around the ferrite core and cooperatively forming an exciting device; and a movable metallic membrane ( 3 ) disposed in close proximity to the exciting device, having a substantially plate body and at least one covering member ( 32 ), wherein the at least one covering member ( 32 ) is an arc-shaped projection extended from at least one lateral edge of the movable metallic membrane ( 3 ) and arranged in an intermittently circumscribing configuration along the lateral edge, such that the arc-shaped covering member ( 3 ) projects to conformingly overlap with respect to portions of the lateral surface of the ferrite core, wherein the movable metallic membrane and the exciting device cooperatively forming a gap there between.