Patent ID: 7184567

Claim:
A thin speaker comprising: a frame of a two-piece structure including a circular dish-shaped upper frame ( 5 ) having a circular center hole ( 5 d ), and a circular dish-shaped bottom frame ( 8 ) having a central circular hole ( 8 a ) and a cylindrical part ( 8 b ) extending inward from a peripheral edge of the circular hole ( 8 a ), the bottom frame ( 8 ) being disposed and coupled concentrically with respect to the upper frame ( 5 ) with an outer peripheral flange part ( 8 d ) of the bottom frame ( 8 ) overlapped to an outer surface of a peripheral edge part of the center hole ( 5 d ) of the upper frame ( 5 ); a vibration system including a cone-shaped diaphragm ( 3 ) coupled at an elastic edge ( 4 ) at an outer periphery of the diaphragm ( 3 ) to an outer peripheral edge of the upper frame ( 8 ), a cylindrical voice coil ( 6 ) having a first end positioned in an interior space of the diaphragm ( 3 ) and having an outer periphery of a second end coupled to an inner peripheral edge of the diaphragm ( 3 ), and an annular damper ( 9 ) coupled at inner peripheral edge to an outer peripheral portion of the second end of the voice coil ( 6 ) and at an outer peripheral edge to the outer surface at the peripheral edge part of the center hole ( 5 d ) of the upper frame ( 5 ) for resiliently holding the inner periphery of the diaphragm ( 3 ); and a magnetic circuit ( 2 ) including a yoke ( 2 a ) comprised of a circular disk part and an outer peripheral wall, a short columnar magnet ( 2 b ) provided within the yoke, a disk-shaped shaped plate ( 2 c ) provided on an outer surface directed axially from the magnet ( 2 b ), and a short columnar supporting member ( 7 ) coupled at an end to an outer surface of the plate ( 2 c ) and inserted within the cylindrical part ( 8 b ) of the bottom frame ( 8 ), the magnetic circuit ( 2 ) forming a magnetic gap positioned in the interior space of the diaphragm ( 3 ) for receiving in the gap the other end having the voice coil ( 6 ).