| 摘要 |
PURPOSE:To prevent the degradation in the resolving power of depth and to obtain videos having a high contrast by obtaining an interference signal with multiple reflection signals as a reference signal. CONSTITUTION:The high-frequency continuous wave electric signal generated in an RF oscillator 1 is converted to RF pulses by a pin diode switch 2. Gate signal pulses are sent at the timing of the interference signal to a gate circuit 4 from a pulse oscillator 3. The RF pulses which are the output of the switch 2 are impressed to a transducer 12. After the resulted reflection signal is amplified by a receiving amplifier 6, the signal is converted by a diode detector 7 to a video band and is applied to the circuit 4 by which the video signal is formed. The length of an acoustic lens medium 13 is so set that the multiple reflection signals in the acoustic lens medium 13 and the reflection signal from near the focus in the sample are superposed. The interference signals are introduced into the circuit 4 if these signals are obtd. The video signal of the interference mode is obtd. if the gate signal from the oscillator 3 is sent to the circuit 4 in synchronization with the timing of the interference signals. |
