Patent ID: 7181041

Claim:
A flat speaker of full-face driving comprising a frame comprised of a flat plate-shaped member, a plurality of annular magnets concentrically disposed on one surface of the frame to have magnetized directions alternately reversed in relation to thickness direction of the magnets, a plurality of concentric annular magnetic gaps arranged to have magnetic flux directions respectively reversed from magnetic flux directions of adjacent ones of the magnetic gaps, a planar diaphragm fixed peripherally to a periphery of the frame while covering over the magnets and the magnetic gaps, and a plurality of voice coils respectively inserted in the magnetic gaps as disposed concentrically annularly on the planar diaphragm at positions corresponding to the magnetic gaps, characterized in that the planar diaphragm has a plurality of ribs radially extending from the center of the concentric annular voice coils and an annular rib connecting the radial ribs, and the plurality of voice coils are provided to the planar diaphragm as vertical-air coils made by the winding a conducting wire a plurality of times vertically stacked in a direction parallel with the direction of the magnets.