| 摘要 |
PURPOSE:To scan a wide range of inspection object and to improve evaluation capability of defects such as defect dimensions by controlling a transmission and reception timing of communication and controlling the opening of an oscillator. CONSTITUTION:A probe 1 consists of ultrasonic oscillators 21-2n, and each of them is connected to a transmitter-receiver 3. An oscillation selecting circuit 6 operates an electronic switch with a selection signal 7, changes over and inputs a trigger signal 4d to any given transmitter-receiver 3, and at the same time, only the reception signal 5 of the transmitter-receiver 3 to which a transmission trigger 4s was inputted is outputted also to the reception signal 5. To the selecting circuit 6, a delay circuit 8 is connected, which delays the transmission trigger signal 4 under the control of a control signal 9, and oututs plural transmission trigger signal 4d of different delay time to the oscillator selecting circuit 6. At the same time, the same delay time control is applied also to a reception signal 5s which is inputted to an adder circuit 10. The adder circuit 10 carries out coherent addition of plural reception signals 5d given a different delay time, and outputs to a signal processing circuit 12. |
