| 摘要 |
PURPOSE:To attain electronic scanning of each parallel stripe form electrode and to decrease the insertion loss to a degree capable of processing a signal by arranging the parallel stripe form electrode on one face of a piezoelectric high polymer film. CONSTITUTION:A piezoelectric substrate 1 is made of a piezoelectric high polymer film and a parallel stripe form electrode 2 whose number of electrode fingers N is 20, electrode finger pitch (p) is 100mum, electrode finger width (a) is 80mum, and electrode cross length (b) is 6mm while being excited at a frequency (f) of 12MHz is formed on one side of the substrate 1, an opposite electrode 3 is formed as shown in dotted lines on other side of the substrate 1 and connected to ground. Moreover, the face of the substrate 1 in contact with water is packed by a packing member made of an acrylic resin whose thickness is 2mm and whose acoustic impedance is close to water. Thus, the ultrasonic wave transducer in liquid is excited by applying a high frequency voltage between the parallel stripe form electrode and the opposed electrode while being arranged in a liquid and a longitudinal ultrasonic wave is radiated into the liquid. Thus, the efficient in-liquid ultrasonic wave transducer is obtained. |
