| 摘要 |
PURPOSE:To obtain a voice coil unit of accurate size in which a magnetic gap can fully be contained, by winding a coil material in a ribbon foil shape, used as a voice coil ribbon, in a layer shape. CONSTITUTION:Voice coil holders 12 fixed in parallel to respective sides of diaphragm 11 and those holders 12 are fitted with a voice coil. Then, magnetic gap 15 formed between magnets 14 fitted at one end part of the internal surface of a couple of plates 13 is positioned. Voice coil unit 20 is obtained by winding bobbin 16 with long ribbon-foil-shaped coil material 21 made of a conductive material of a little bit narrower width size than the unit corresponding to the width size of gap 15 and when the voice coil is formed by coil-winding cylindrical bobbin 16 with used coil material 21, the precision in the magnetic gap direction is fixed with a thickness determined by the thickness of the foil material and the quantity of adhesives, so that gap 15 can effectively be utilized. |
