| 摘要 |
PURPOSE:To improve the reproducing capability at a high frequency band by forming a chromium layer to both faces or one face of a diaphragm in the diaphragm for speaker where a phenol resin is impregnated to a cloth base and the base is formed into a dome by heat forming. CONSTITUTION:The chromium layer 2 having a thickness of 2mum is formed on the surface of the diaphragm main body 1 of dome-shape formed by heating while a phenol resin is impregnated to the cloth base by means of the vacuum vapor deposition method or the sputtering method. In order to protect the chromium layer 2, a protection layer 3 made of an epoxy resin having a thickness of 2-3mum is formed. In the frequency characteristic as shown in the fig., broken lines show the case that no surface processing is treated to the diaphragm conventionally and solid lines illustrate the case that the surface chromium layer 2 is formed. As clearly shown in both the plots, the chromium layer 2 formed on the surface of the diaphragm gives the effect of expanding the high frequency limit frequency. |
