JPS6439199A - Speaker device - Google Patents

Abstract

PURPOSE:To eliminate the need of a strong stationary magnet, to miniaturize the titled device and to reduce unfavorable influence to an outside by providing a coil to convert an electroacoustic signal into a magnetic flux and its auxiliary coil and a diaphragm partly using a superconductive material. CONSTITUTION:The electroacoustic signal is separated into a low frequency part and a high frequency part according to its frequency component, the low frequency part is supplied to a terminal B and the high frequency part is supplied to terminals A, A' respectively, converted into a magnetic flux by coils 4, 5 and 6. Simultaneously, a constant electric current flows to terminals C, C' and D and a constant magnetic flux is generated in auxiliary coils 8, 9 and 10. The magnetic flux generated by the coils 4, 5 and 6 and the coils 8, 9 and 10 generates a magnetic flux in the opposite direction to a superconductive material 7 partly mounted on a diaphragm 1 arranged in the front, and its repulsive force is added to the diaphragm 1. The force moves the diaphragm 1 until it is canceled by a damper device 3, and converted into a sound wave as the result. Thus, since the strong stationary magnet is not necessary, the device can be miniaturized and the unfavorable influence to the outside is reduced.