A loudspeaker includes a frame; a magnetic circuit supported by the frame; a voice coil disposed in a magnetic gap of the magnetic circuit so as to be able to vibrate freely in the gap; a diaphragm connected to the frame at the outer rim thereof via a first edge and connected to the voice coil at the inner rim thereof; a damper connected to the voice coil at the inner rim thereof, the damper being closer to the magnetic circuit than the diaphragm is close to the magnetic circuit; and a second edge connecting the outer rim of the damper to the frame. The second edge has a protrusion protruding either toward the diaphragm or in the opposite direction. The second edge is coupled to a third edge having a protrusion protruding at least in the opposite direction in which the protrusion of the second edge protrudes. This structure enables the loudspeaker to have little distortion and high driving efficiency.
1. A loudspeaker comprising:
a frame;
a magnetic circuit supported by the frame;
a voice coil disposed in a magnetic gap of the magnetic circuit so as to be able to vibrate freely in the gap;
a diaphragm connected to the frame at an outer rim thereof via a first edge and connected to the voice coil at an inner rim thereof;
a damper connected to the voice coil at an inner rim thereof, the damper being closer to the magnetic circuit than the diaphragm is close to the magnetic circuit;
a second edge having first and second ends for respectively connecting an outer rim of the damper to the frame; and
a third edge having first and second ends each coupled to the respective first and second ends of the second edge, wherein the second edge has a protrusion protruding one of toward the diaphragm and toward the frame opposite to each other; and
the third edge has a protrusion protruding at least in an opposite direction in which the protrusion of the second edge protrudes.
2. The loudspeaker of claim 1 wherein the damper, the second edge, and the third edge form a combination and the combination has a larger Young's modulus than the first edge.
3. The loudspeaker of claim 2 , wherein the third edge has a lower Young's modulus than the second edge.
4. The loudspeaker of claim 2 , wherein the third edge is made of a foamed resin, and the second edge is made of a rubber material.
5. The loudspeaker of claim 4 , wherein the first edge and the third edge are made of an urethane resin, and the first edge has a lower Young's modulus than the third edge.
6. The loudspeaker of claim 1 , wherein the third edge has a Young's modulus larger than the Young's modulus of the first edge and lower than the Young's modulus of the second edge.
7. A loudspeaker comprising:
a frame;
a magnetic circuit supported by the frame;
a voice coil disposed in a magnetic gap of the magnetic circuit so as to be able to vibrate freely in the gap;
a diaphragm connected to the frame at an outer rim thereof via a first edge and connected to the voice coil at an inner rim thereof;
a damper connected to the voice coil at an inner rim thereof, the damper being between the diaphragm and the frame; and
a coupled edge connecting an outer rim of the damper to the frame, the coupled edge having an upward protrusion protruding above a surface of the damper and a downward protrusion protruding below the surface of the damper,
wherein the upward protrusion of the coupled edge has a Young's modulus larger than the Young's modulus of the first edge and lower than the Young's modulus of the downward protrusion of the coupled edge.
8. The loudspeaker of claim 7 , wherein the damper and the coupled edge form a combination, and the combination has a larger Young's modulus than the first edge.
9. The loudspeaker of claim 7 , wherein the first edge has an upward protrusion.
10. The loudspeaker of claim 7 , wherein the upward protrusion is opposed to the downward protrusion.
11. The loudspeaker of claim 7 , wherein the upward protrusion is adjacent to the downward protrusion.