公开(公告)号：EP0996311A4

公开(公告)日：2006-03-29

申请号：EP98923146

申请日：1998-06-05

申请人： FPS INC

发明人： DENDA SAKUZO ,  MIYAZAKI TOSHIIKU

IPC分类号： H04R9/00 ,  H04R7/04 ,  H04R9/04

CPC分类号： H04R7/04 ,  H04R9/047

摘要： A planar acoustic transducer wherein flat square-shaped permanent magnets (m18, m28, m38) are arranged on a yoke (20) with their pole faces upside so that the pole faces having different polarities may be positioned alternately. A vibrating film (26) is arranged in parallel with the pole faces of the magnets (m18, m28, m38) on the upper surface side of the yoke (20), and spirally wound paired coils (L18, L28, L38) are arranged correspondingly to the magnets (m18, m28, m38) on the front and rear surfaces of the film (26). Each of paired coils (L18, L28, L38) is spirally wound so that the paired coil may have a similar figure to that of the outer edge of the pole face of the corresponding magnet (m18, m28, m38), and the inner periphery of the coil may be positioned on the outside of the pole face from the position corresponding to the outer edge of the pole face, and then, the outer peripheries of the coils may not overlap each other. Therefore, the paired coils (L18, L28, L38) are interlinked with magnetic fluxes in the direction along the vibrating film (26).