| 摘要 |
PURPOSE:To simplify the manufacturing process and to attain remarkable cost reduction, by using a single material of inorganic foamed body for forming an incorporated hollow construction. CONSTITUTION:A diaphragm for speaker 14 is formed with an incorporated hollow construction of an inorganic foamed body 11. Cavities 12 are formed with a prescribed pitch from the outer circumference of the foamed body 11 to the center and ribs 13 and provided radially. Thus, the same property as Al is attained with low cost. |
