SPEAKER

• Main Authors: SAGAWA HIROYUKI, INANAGA KIYOFUMI, TSUKAMOTO SHIRO
• Format: Patent
• Language: English
• Published: 27.11.1989
• Subjects: DEAF-AID SETS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; PUBLIC ADDRESS SYSTEMS

PURPOSE:To improve a coupling coefficient between a coil and a conductive part and to improve the sensitivity of a speaker by providing a feeding coil, which is faced with the conductive part with an interval, and forming the ring- shaped magnetic substance of high permeability in the inner circumference of the coil. CONSTITUTION:A magnetic gap is formed by a pole piece 2 and a top plate 4 and a conductive part 7, which is united with a diaphragm 6, is inserted. When a sound current flows through lead wires 9A and 9B to a feeding coil 5, a magnetic flux is generated in the coil 5 and this magnetic flux crosses with the conductive part 7. Accordingly, moving force due to an induction current is generated in the conductive part 7 and the diaphragm 6 is oscillated. A ring-shaped magnetic substance of the high permeability is provided in the inner circumference of the coil 5 and thus, the coupling coefficient between the coil 5 and conductive part 7 is improved. Accordingly, the sensitivity of the speaker is improved and the inductance of the coil is caused to rise up base up by the magnetic substance. Then, a reproducing limit low area frequency can be lowered.