Ultrasonic inspection apparatus and ultrasonic inspection method

1. An ultrasonic inspection apparatus comprising:

an ultrasonic array probe having a plurality of ultrasonic elements arranged at predetermined positions for transmitting ultrasonic waves to a test object and receiving the ultrasonic waves reflected by the test object;

a test object information acquiring section for acquiring information on the test object;

an input unit for receiving inputs from outside and also from the test object information acquiring section;

an estimated shape reflected wave arrival time calculator for computing an estimated shape reflected wave arrival time of each of estimated shape reflected waves on the basis of n estimated sound velocity in the test object, the estimated shape reflected wave arrival time being the estimated time for the estimated shape reflected wave to arrive at the ultrasonic elements when the ultrasonic waves are reflected at a shape-indicating reflection part thereof;

an actual shape reflected wave arrival time extractor for extracting the actual shape reflected wave arrival time on the basis of n actual shape reflected wave transmitted from the ultrasonic element used for ultrasonic wave transmission, propagated through the test object, reflected by the shape-indicating reflection part and received by each of the ultrasonic elements used for receiving the ultrasonic waves;

a shape reflected waves time difference calculator for computing a shape reflected waves time difference obtained by subtracting the actual shape reflected wave arrival time from the estimated shape reflected wave arrival time as shape reflected waves time difference; and

a delay time calculator for computing delay times each of which is to be used for mutually shifting corresponding timing of ultrasonic wave transmission and reception by the ultrasonic elements, the delay time calculator using the shape reflected waves time differences for subtracting from each delay time,

wherein the shape-indicating reflection part is a part of the test object that relates to an overall shape of the test object or a representative part of the test object in terms of the shape.

2. The ultrasonic inspection apparatus according to claim 1 , wherein

the delay time calculator is configured to multiply the shape reflected waves time difference by a weighting factor.

3. The ultrasonic inspection apparatus according to claim 1 , further comprising:

a synthesizing calculator for computationally determining a synthetic waveform of the ultrasonic waves received by the ultrasonic elements.

4. The ultrasonic inspection apparatus according to claim 3 , further comprising:

an estimated shape reflected wave intensity calculator for computing an estimated shape reflected wave intensity that is an intensity of the estimated shape reflected wave;

an actual shape reflected wave intensity extractor for extracting an actual shape reflected wave intensity that is the intensity of the actual shape reflected wave; and

a shape reflected wave intensity ratio comparator for computing a ratio of the estimated shape reflected wave intensity to the actual shape reflected wave intensity as a correction gain; wherein

the synthesizing calculator computationally determining the synthetic waveform after correcting the ultrasonic waves received by the ultrasonic elements respectively multiplied by the correction gains.

5. The ultrasonic inspection apparatus according to claim 3 , further comprising:

an actual sound velocity calculator for computing an actual sound velocity by multiplying the estimated sound velocity by a ratio of the estimated shape reflected wave arrival time to the actual shape reflected wave arrival time; and

an image generator for computationally determining an image data to be displayed by using the synthetic waveform based on a delay time calculated using the actual sound velocity.

6. An ultrasonic inspection method comprising:

an ultrasonic wave transmitting/receiving step for each of a plurality of ultrasonic elements belonging to an ultrasonic wave array probe to transmit an ultrasonic wave to a test object and receive reflected waves from the test object;

an estimated sound velocity calculating step for calculating an estimated sound velocity based on information relating to the test object gained by a test object information acquiring section and input unit;

an estimated shape reflected wave arrival time computing step for an estimated shape reflected wave arrival time calculator to calculate the estimated shape reflected wave arrival time on the basis of an estimated sound velocity in the test object;

an actual shape reflected wave arrival time extracting step for an actual shape reflected wave arrival extracting section to extract an actual shape reflected wave arrival time on the basis of an actual shape reflected wave transmitted by the ultrasonic elements to be used for transmission of ha ultrasonic wave, propagated through inside of the test object, reflected by a shape-indicating reflection part and received by the ultrasonic element to be used for reception of the ultrasonic wave;

a shape reflected waves time difference computing step for an shape reflected wave time difference computing section to calculate a time difference between the estimated shape reflected wave arrival time and the actual shape reflected wave arrival time as a shape reflected waves time difference; and

a delay time computing step for a delay time calculator to calculate delay times each of which is to be used for mutually shifting corresponding timing of transmissions and receptions of ultrasonic waves by the ultrasonic elements, using the shape reflected waves time differences for subtracting from each delay time,

wherein the shape-indicating reflection part is a part of the test object that relates to an overall shape of the test object or a representative part of the test object in terms of the shape.