| 摘要 |
PURPOSE:To increase the efficiency of an electroacoustic transducing in a thickness piezoelectric type electroacoustic transducer by backing one surface of a piezoelectric macromolecular film with a foamed material. CONSTITUTION:Sandwich piezoelectric high molecular film 1 with thin film electrodes 2 and 2' such as aluminium nickel, back the outside of one electrode 2' with foamed material 3 such as urethan foam and styrofoam and, if necessary, hold the backed film on thick base board 4 such as metal and plastics. When the tinckness piezoelectric type electroacoustic transducer is constituted as mentioned above, the efficiency of electroacoustic transducing is increased by the reflecting effect caused by foamed material 3 and the efficiency will be more increased by defining the frequency to be applied within the range of 0.6-1.4 times the standard frequency of thickness. |
