Patent ID: 7095864

Claim:
An electrostatic loudspeaker comprising a multi-layer panel incorporating an electrically insulating middle layer ( 2 , 2 ′, 2 ″) sandwiched between first and second electrically conducting outer layers ( 3 , 3 ′, 3 ″; 4 , 4 ′, 4 ″), at least one of the layers ( 2 , 2 ′, 2 ″; 3 , 3 ′, 3 ″; 4 , 4 ′, 4 ″) having a profiled surface where it contacts the surface of another of the layers, the profiled surface being an uneven surface and signal means ( 11 ) for applying an alternating electrical voltage across the first and second layers ( 3 , 3 ′, 3 ″; 4 , 4 ′, 4 ″) to initiate vibration of the first layer ( 3 , 3 ′, 3 ″) relative to the middle layer ( 2 , 2 ′, 2 ″) due to variation of the electrostatic forces acting between the layers ( 2 , 2 ′, 2 ″; 3 , 3 ′, 3 ″; 4 , 4 ′, 4 ″).