Abstract: A transmitter for modulating an externally supplied audio signal according to a predetermined modulation system and for transmitting an obtained modulation signal includes a modulator for modulating the audio signal according to the modulation system; a balance convertor for converting the modulation signal in an unbalanced mode generated by the modulator into a balanced mode; and an antenna having a predetermined length formed by a leakage transmission line, the antenna emitting the modulation signal converted into the balanced mode.

Abstract: A transmitter for modulating an externally supplied audio signal according to a predetermined modulation system and for transmitting an obtained modulation signal includes a modulator for modulating the audio signal according to the modulation system; a balance convertor for converting the modulation signal in an unbalanced mode generated by the modulator into a balanced mode; and an antenna having a predetermined length formed by a leakage transmission line, the antenna emitting the modulation signal converted into the balanced mode.

Abstract: In a speaker which is constructed in a manner that a voice coil bobbin is attached to an inner circumferential portion of a cone type diaphragm while a voice coil is wound around the voice coil bobbin, and the voice coil is inserted into a magnetic gap, the voice coil bobbin is formed of a conductive material and is provided with a gap extending a lengthwise direction so as to form a one-turn voice coil, and the voice coil is fixed to the voice coil bobbin by a soft bonding agent while a very high frequency audio signal is supplied to the one-turn voice coil forming the voice coil bobbin.

Abstract: In a speaker which is constructed in a manner that a voice coil bobbin is attached to an inner circumferential portion of a cone type diaphragm while a voice coil is wound around the voice coil bobbin, and the voice coil is inserted into a magnetic gap, the voice coil bobbin is formed of a conductive material while the voice coil being fixed is the voice coil bobbin by a soft bonding agent, and in a very high range, the voice coil is operated as a driving coil while the voice coil bobbin is operated as a short coil.

Abstract: An electromagnetic induction type acoustic transducer apparatus including a magnetic gap formed between a plate and a pole piece serving as assemblies of a magnetic circuit, a conductive ring attached to a diaphragm, the diaphragm interposed within the magnetic gap for generating sounds when it is vibrated, and a flat coil disposed in the plate or the pole piece at the position opposing the magnetic gap and of which winding is increased from the vibration direction of the diaphragm to the direction perpendicular to the vibration direction of the diaphragm, wherein a width of the magnetic gap can be reduced.