| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method by which a natural sound generated by wood and high appearance quality are obtained, a flat characteristic for controlling a sound pressure dip from a medium compass through a high compass is secured, and the frequency characteristic of the high compass is improved. SOLUTION: A diaphragm 11 is formed in a first plate thickness range D including all of a central vibration portion 19 and in a second plate thickness range D-1 which is thinner than a peripheral vibration portion 21 by a process to form a stuck sheet 29 by sticking a reinforced sheet 24 on one surface of a wooden sheet 23 comprised of a natural tree, by a process to impregnate a thermosetting resin 31 into the stuck sheet 29, and by a process to laminate and adhere the stuck sheet 29 processed in a size so as to be the approximately-dome-shaped central vibration portion 19 and a synthetic resin film 25 which is formed around the entire periphery of the central vibration portion 19 and becomes an approximately-dome-shaped peripheral vibration portion 21 fixed to a frame 13 to store a magnetic circuit 9 by the end of an edge 21b after the impregnated thermosetting resin 31 is dried. COPYRIGHT: (C)2008,JPO&INPIT
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