| 摘要 |
PURPOSE:To detect automatically the existence of bubble that is developed in an acoustic lens by detecting selectively the detection signal issued by the reflection wave from an acoustic lens and comparing the detection value with a specific threshhold value. CONSTITUTION:A detection signal issued by the reflection wave from a spherical concave surface lens 2 of an acoustic lens 3 is selectively detected by sample holding. This detected voltage is compared in a comparator 17 with a reference voltage Vr1 of a threshold value. In other words, when the detection output voltage VB1 by the first reflection wave is larger than Vr, the comparator is made to develop ON output. Therefore, if a bubble is in the concave surface lens 2, the detection output VB1 becomes larger than Vr, making the comparator 17 develop ON output, and by this the existence of bubble is immediately detected. With this arrangement the existence of bubble that is produced in the spherical concave lens 2 of the acoustic lens 3 can be automatically detected. |
