Sound producing device
A sound producing device includes a diaphragm, an armature extending parallel to the diaphragm, a coil having a wire wound around the armature in multiple turns, multiple magnets facing the armature, a yoke supporting the multiple magnets, a transmitting body configured to transmit a vibration of the armature to the diaphragm, a driving-side frame on which the armature, the coil, and the yoke supporting the multiple magnets are mounted, and a vibration-side frame including an opening in which the diaphragm is vibratably supported. The driving-side frame and the vibration-side frame are placed one over the other.
1. A sound producing device comprising:
a diaphragm;
an armature extending parallel to the diaphragm;
a coil having a wire wound around the armature in multiple turns;
a plurality of magnets facing the armature;
a yoke supporting the plurality of magnets;
a transmitting body configured to transmit a vibration of the armature to the diaphragm;
a driving-side frame including a first plane surface on which the armature, the coil, and the yoke supporting the plurality of magnets are attached;
a vibration-side frame including an opening in which the diaphragm is vibratably supported, the vibration-side frame having a surface that is joined surface to surface to a second plane surface of the driving-side frame, the second plane surface being on an opposite side of the driving-side frame from the first plane surface such that the driving-side frame and the vibration-side frame are placed one over another; and
a first case and a second case that are fixed to the first plane surface and the second plane surface, respectively, of the driving-side frame such that the driving-side frame is held between the first case and the second case.
2. The sound producing device as claimed in claim 1 , wherein a proximal end section of the armature and the yoke are attached with reference to the first plane surface of the driving-side frame.
3. The sound producing device as claimed in claim 1 , wherein
the diaphragm is placed in the opening formed in the vibration-side frame,
a gap between an edge of the opening and an edge of the diaphragm is closed by a flexible sheet, and
the opening formed in the vibration-side frame has a larger open area than any opening formed in the driving-side frame.
4. The sound producing device as claimed in claim 3 , wherein
the driving-side frame and the vibration-side frame are formed of different materials, and
a bonding strength of the flexible sheet and the vibration-side frame is higher than a bonding strength of the flexible sheet and the driving-side frame when the flexible sheet is bonded to the driving-side frame.
5. The sound producing device as claimed in claim 1 , wherein
the driving-side frame is formed of a magnetic material, and
the vibration-side frame is formed of a non-magnetic material.
6. The sound producing device as claimed in claim 5 , wherein the driving-side frame and the armature form a magnetic path.
7. The sound producing device as claimed in claim 1 , wherein a recess is formed in a distal end section of the armature to be open in a direction away from a proximal end section thereof, the recess having a greater width than a connecting end section of the transmitting body, the connecting end section being positioned in the recess and fixed to the armature.
8. The sound producing device as claimed in claim 7 , wherein a cross-sectional area of the transmitting body is smaller in the connecting end section than in a section fixed to the diaphragm.
9. The sound producing device as claimed in claim 7 , wherein a cross-sectional area of the transmitting body is greater in the connecting end section than in a section fixed to the diaphragm.