DIAPHRAGM FOR SPEAKER AND ITS MANUFACTURE

PURPOSE:To obtain excellent sound pressure versus frequency characteristic, distortion ratio and phase characteristic and to simplify the forming process by forming a 3-dimensional textile or a multiple textile among textiles blended with carbon fibers, thermoplastic resins and threads to be a prescribed shape. CONSTITUTION:Carbon fibers are used for weft 1 and carbon fibers and polycarbonate fibers are used for a warp 2 as textile and they are woven in 3-dimensional way. The textile is inserted in a metallic die with a heater and a cooler, after the polycarbonate fibers are molten and formed, the fibers are cooled while keeping a press pressure. Then the metallic die is open and the forming is extracted. Since the material has a high elastic modulus the bending rigidity of the diaphragm is very high by using the material for the diaphragm and deformation of the diaphragm or production of split vibration during vibration is very less. Since the specific elastic modulus is large in the forming made of the 3-dimension textile or multiple textile in a prescribed shape, the high resonance frequency is high and the reproduction band of a speaker is extended toward high frequencies and a signal up to a high frequency is reproduced.