Electro-acoustic micro-transducer having three-mode reproduction feature

An electro-acoustic micro-transducer comprising:

• a yoke formed of an internal circular groove and first and second vertical incision portions for removing a predetermined vertical wall at each side surface;
• a permanent magnet installed in the groove of the yoke, for generating a non-alternating magnetic field;
• a plate mounted on the upper surface of the permanent magnet, for forming a magnetic gap between the outer circumferential surface and the upper end of the yoke;
• a coil wound on a bobbin, which generates an alternating magnetic field when a drive signal is applied and is disposed in the magnetic gap to be displaced up and down according to an interaction with a non-alternating magnetic field generated from the permanent magnet;
• a cylindrical frame in which the outer circumferential portion surrounds the yoke at the state where the yoke is set to be positioned in the center, the outer circumferential portion is perpendicularly extensively formed in such a manner that a groove is formed therein and first and second externally communicating throughholes are formed in the first and second groove spaces opposing the incision portion of the yoke;
• and
• a vibration diaphragm in which the bobbin is supported and the outer circumferential portion is supported in the upper end of the frame, for generating an acoustic sound in correspondence to the drive signal when the bobbin is displaced up and down,
• wherein first and second groove spaces respectively formed by the first and second incision portions and the first and second groove spaces are formed of a magnitude of preventing first and second connection portions of the first and second flexible wires fixed to the bobbin from contacting the yoke and the frame during vertical vibration of the bobbin, in order to apply the drive signal externally, to thereby extend an up-and-down vibration width of the bobbin.