| 摘要 |
PURPOSE:To obtain a diagnosing apparatus which allows radiation of ultrasonic beams with two kinds of drive frequencies in the same direction, by using a lambda/4 type driving vibrator in which a plate material is laminated on a piezo-electric vibrator, with the acoustic impedance equal to the vibrator. CONSTITUTION:A piezo-electric vibrator 1, a plate material 3 and electrodes 2 and 2' are laminated by integral sintering to form a lambda/4 type driving vibrator. A ferrite rubber packing material 6 adheres to the vibrator by an adhesive material layer 5 and the thickness of an acoustic matching layer 4 is adjusted to match a lambda/2 resonance mode. A transmitting/receiving system is so arranged that a lambda/4 resonance mode pulser 21 (2-wave sine wave burst of 3.1MHz), a low pass filter 22 and a lambda/2 resonance mode pulser 24 (3-wave sine wave burst of 6.4MHz) and a high pass filter 25 are connected to a common receiver 23. Then, an ultrasonic vibrator 26 is connected through a changeover switch. |
