| 摘要 |
PURPOSE:To obtain high performance and to reduce the size of an element on the whole by reducing the necessary amount of a sound absorbing material by increasing a sound absorption coefficient, by using resin which contains a 25- 45wt% inorganic substances whose grain size is one-tenth the wavelength of an elastic surface wave. CONSTITUTION:In resin selected among oleoresin, epoxy resin, acrylic resin, phenollic resin, and ''Teflon '' resin, a 25-45wt% inorganic substance whose gr ain size is one-tenth the wavelength of a surface acoustic wave is contained to obtain a sound absorbing material 7, which is applied between transducers 2 and 3, and the end surfaces of a substrate. As the inorganic substance, a piezoelectric substance, such as LiTaO3, LiNbO3, and Cd3GaO12, an oxide of a nonpiezoelectric dielectric substance, such as SiO2, Al2O3, MnO2, and CaO, or a metal, such as metallic salt, is used. |
