Patent ID: 8588456

Claim:
An acoustic conversion device comprising: a driving unit including (a) a yoke, (b) a pair of magnets disposed so as to face one another, the pair of magnets attached to the yoke, (c) a coil configured to receive a driving current, (d) a vibrating portion passed through the coil and configured to vibrate when the driving current is supplied to the coil, and (e) an armature disposed between said pair of magnets; and a diaphragm unit including (a) a holding frame having an opening, (b) a resin film attached to the holding frame, the resin film at least covering the opening of the holding frame, (c) a diaphragm on the inner side of the holding frame, the diaphragm attached to the resin film, and (d) a beam, wherein, a joint recessed portion is formed in said vibrating portion of said armature, the beam portion comprises (a) a tip integrally formed with the diaphragm, (b) at least a portion of the beam is combined with the vibrating portion of the driving unit, (c) a base continuous with the diaphragm, and (d) a joint portion continuous with the base, the joint portion inserted into the joint recessed portion, and the base of the beam portion has a width that increases from the joint portion to the diaphragm.