JP2619142B2 - Ultrasonic inspection equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ultrasonic wave that scans and irradiates a test material with an ultrasonic wave, and inspects the surface state of the test material and the presence or absence of internal defects based on the reflected wave. It relates to an inspection device.

2. Description of the Related Art An ultrasonic inspection apparatus can detect a defect inside a test material without destroying the test material, and is used in many fields. The presence or absence of a defect inside the test material is often checked in a predetermined range of the test material, in which case the predetermined range on the surface of the test material is radiated from the probe of the ultrasonic inspection apparatus. The inspection is performed by scanning with the ultrasonic waves to be performed. As this probe, an array probe constituted by arranging many piezoelectric elements in a line has been put to practical use. Hereinafter, an ultrasonic inspection apparatus using such an array probe will be described.

FIG. 1 is a perspective view of a scanner section of a conventional ultrasonic inspection apparatus, and FIGS. 2 and 3 are a plan view and a side view of an array probe, respectively. In each figure, 1 is a water tank for inspection, 2 is water put in the water tank 1, and 3 is a test material placed on the bottom surface of the water tank 1. Reference numeral 4 denotes a scanner, which comprises the following members. That is, 5 is a scanner table on which the water tank 1 is placed,
6 is a frame fixed to the scanner base 5, 7 is an arm mounted on the frame 6, 8 is a holder mounted on the arm 7, 9 is a pole mounted on the holder 8, and 10 is an array probe. is there. The frame 6 is provided with an arm 7 by a mechanism (not shown).
Can be driven in the Y-axis direction, the arm 7 can drive the holder 8 in the X-axis direction by a mechanism (not shown), and the holder 8 can cooperate with the pole 9 by a mechanism (not shown). Move the probe 10 in the Z-axis direction (X-axis and Y-axis).
(In a direction perpendicular to the axis).

The array probe 10 has a configuration in which many small piezoelectric elements (hereinafter, these piezoelectric elements are referred to as array probes) are arranged in a line, and the arrangement direction coincides with the X-axis direction. Each array probe emits an ultrasonic wave when given a pulse, and converts a reflected wave of the ultrasonic wave from the test material 3 into an electric signal proportional to the ultrasonic wave. Each array transducer in FIGS. 2 and 3 is shown generally at 10 ₁ to 10 _n. Note that black points indicate sampling points, YP indicates a sampling pitch in the Y-axis direction, and XP indicates a sampling pitch in the X-axis direction. Further, AP denotes the respective array transducer 10 ₁ to 10 _n mutual pitch. Reference numeral 11 denotes a case for storing the array probe 10 and the like.

Here, the outline of the function of the array probe 10 shown in each of the above drawings will be described with reference to FIG. 4 and FIG. In FIG. 4, T _{1 to} T ₉ are array transducers arranged in a line, D _{1 to} D ₉ are delay elements connected to each array transducer T _{1 to} T ₉ , and p is each array transducer T ₁ a pulse input to through T _9. Delay element
The delay times (t ₁₉ ) of D ₁ and D ₉ are set equal. Similarly, the delay times (t ₂₈ ) of the delay elements D ₂ and D ₈ and the delay elements D ₃ and D ₇
Delay time (t ₃₇ ), delay time of delay elements D ₄ and D ₆ (t ₄₆ )
Are also set equally. The relationship of the delay time set is the delay time of the delay element D ₅ in the formula of relationship When t _5.

t ₁₉ <t ₂₈ <t ₃₇ <t ₄₆ <t ₅ (1) Now, the delay time of each of the delay elements D _{1 to} D ₉ is set to a predetermined value while maintaining the relationship of the above equation (1). When the pulse p is inputted, the ultrasonic waves radiated from the array transducers T _{1 to} T ₉ are converted into the array transducers T ₁ and T according to the set delay time.
Earliest _9, also are slowest radiated from the array transducer T _5. The ultrasonic waves radiated in this manner spread radially and travel, but there are points where the maximum amplitudes of the vibrations of the radiated ultrasonic waves of the array transducers all match. In FIG. 4, this point is indicated by the symbol F. The size of the ultrasonic wave at this point F is compared with the size of the ultrasonic wave at other points.
Since it is so large, it is as if the ultrasonic waves from each of the array transducers T _{1 to} T ₉ were focused on the point F as shown by the broken line. In other words, if an appropriate delay is given to the ultrasonic radiation from the arrayed transducers, it is possible to achieve a state similar to the state where those ultrasonic waves are focused at the point F. This point F is called a focal point. Further stated, the array transducer T ₁ through T _9, so that the ultrasonic beam B as shown by a broken line which focuses at the focal point F is output. (1)
If each delay time is set smaller than the above-mentioned delay time while maintaining the relationship of the formula, the focal point F is shifted by a dashed line (beam B ').
The focus shifts to a longer focal point F 'as shown by. Therefore, by adjusting the delay time of each of the delay elements D _{1 to} D ₉ , the position of the focal point can be selected, and when this is applied to the inspection of the test material 3, the depth of the inspection site is determined. Can be selected.

FIG. 5 is an explanatory diagram of the function of the array probe 10 shown in FIGS. 2 and 3. In this figure, 10 ₁ to 10 _n are the same array transducer as shown in FIG. 2, the array transducer 10 ₁
Although not shown, delay elements are connected to .about.10 _n , respectively. In the illustrated example, first, m array transducers 10
By selecting ₁ to 10 _m and appropriately setting the delay time of the ultrasonic wave emitted from them, the ultrasonic wave is apparently focused on one focus as described above. This focus is labeled in FIG.
F ₁ and the apparent ultrasonic beam are denoted by B ₁ . Next, the same m-number of array elements 10 ₂ to 10 _{m + 1} is shifted by one array transducer, the previous array transducer 10 ₁
A delay time of the same pattern as the delay time given to ~ 10 _m is given. The focus of this time by the symbol F _2, ultrasonic beam code
It is shown in B _2. Hereinafter, the array transducers are sequentially switched one by one, and finally, the array transducers 10 _{n-m + 1} to 10 _n are selected to give the same pattern of delay time, and the focal point F _{n-m + 1} , Obtain a sound beam B _{n-m + 1} . By such means, resulting in will be scanned by the ultrasonic up by connexion focus F ₁ ~F _{n-m + 1} to the array probe 10 is performed. Since such scanning is performed electronically at high speed, it is hereinafter referred to as electronic scanning. In FIG. 5, AP indicates an array oscillator pitch, SP indicates a sampling pitch, and both are equal in the case shown.

Next, a control unit of an ultrasonic inspection apparatus using the array probe will be described.

FIG. 6 is a block diagram of the control unit. In FIG.
10 is an array probe described above, 7M and 8M are motors for driving the arm 7 in the Y-axis direction and the holder 8 in the X-axis direction, and 7E and 8E are for outputting drive signals to the motors 7M and 8M, respectively. And an encoder that detects and outputs the amount of drive of these. The motor 8M and the encoder 8E are used to position the array probe 10 at an appropriate position in the water tank 1, and do not participate in the X-axis ultrasonic scanning described later. Reference numeral 20 denotes a signal processing device, and a CPU
(Central processing unit) 20a, image memory 20 for image processing
b, an interface 20c for input / output between the signal processing device 20 and an external circuit, a keyboard 20d, and the like. The signal processing device 20 includes a storage element such as a RAM and a ROM and other elements, but is not shown. Reference numeral 21 denotes a display device.

Reference numeral 22 denotes a transmission control circuit, which receives a command from the CPU 20a.
The delay time and the selection and switching of the array transducer described with reference to FIGS. 4 and 5 are controlled. 23 is the pulse p
Which is provided for each array transducer. Reference numeral 24 denotes a receiver for receiving and amplifying an ultrasonic reflected wave signal from the array transducer, and is provided for each array transducer. A reception control circuit 25 controls the above-described delay, selection, and switching for signals from each array transducer. 26 is a waveform adder, which adds all received signals output at the same time as a result of the delay in the reception control circuit 25. Reference numeral 27 denotes a main amplifier for amplifying the output signal of the waveform adder 26, and the degree of amplification is determined by a command from the CPU 20a based on an external input from the keyboard 20d or the like. Reference numeral 28 denotes a peak detector, which has a gate function of collecting only a signal in a predetermined depth range from the surface of the test material 3 and a function of holding and outputting only a peak value within the range. ing. Reference numeral 29 denotes an A / D converter for converting the peak value held by the peak detector 28 into a corresponding digital value. The operation of this control unit will be described with reference to FIG.

FIG. 7 is a more detailed block diagram of the control unit for facilitating the description of the operation of the control unit shown in FIG.
In FIG. 7, the same or equivalent parts as those shown in FIG. 6 are denoted by the same reference numerals. Also, motors 7M, 8M, encoder 7E,
Illustration of 8E and keyboard 20d is omitted. Further, although two array probes 10 are illustrated, this means that the array probe is a transmission / reception split type array probe which uses one for transmission and the other for reception. The array probe is a technique used for the purpose of improving the resolution in the depth direction and the like. As described above, in the case of the transmission / reception type array probe using the same array transducer at the time of transmission and reception, the configuration and operation of the control unit are the same as those of the transmission / reception split type array probe. is there.

In FIG. 7, reference numeral 22a denotes a clock pulse generator, 22b denotes a transmission beam focusing circuit, and 22c denotes a transmission side matrix switch network. These components constitute the transmission control circuit 22 shown in FIG. The reception beam focusing circuits 25 and 26 constitute a part of the reception control circuit 25 and the waveform adder 26 shown in FIG.

Now, assuming that one ultrasonic beam is transmitted and received by eight array transducers, the transmission beam focusing circuit 22b
Outputs a signal given to eight pulse generators of the pulse generator group 23 in a predetermined delay pattern with reference to the clock pulse from the clock pulse generator 22a. The transmission-side matrix switch network 22c determines which array transducer to apply the eight signals output from the transmission beam focusing circuit 22b in a predetermined delay pattern, that is, which pulse generator, in accordance with a command from the CPU 20a. Is selected, and switching is performed according to the selection. With this, the pulse generator
At 23, signals are output from the selected eight consecutive pulse generators in the above-described predetermined delay pattern, and the array transducers connected to these pulse generators are excited, and the desired ultrasonic wave is output. A beam is output.

On the other hand, the receiving-side array transducer receives the ultrasonic wave, and outputs a signal corresponding thereto to the preamplifier connected to each of the array transducers of the preamplifier group 24, and these signals are amplified. The receiving-side matrix switch circuit 25 switches the signal amplified by each preamplifier in accordance with a command from the CPU 20a to a predetermined one of the delay elements constituting the delay pattern in the reception beam focusing circuits 25 and 26. I do. As a result, each of the received eight signals is converted into the reception beam focusing circuit 2
At the output stage of each of the 5, 26 delay elements, they are added with the same output timing.

The added signal is amplified by the main amplifier 27 at the amplification degree set by the command of the CPU 20a, and the peak detector 28,
The signal is converted into a digital value via the A / D converter 29. The converted value is stored in the address of the image memory 20b obtained by the address calculation of the CPU 20a.

The operation of transmitting and receiving one ultrasonic beam by the eight array transducers has been described above. However, by appropriately switching and controlling the transmission-side matrix switch network 22c and the reception-side matrix switch network 25, the array probe
Each of the ten array transducers 10 ₁ to 10 _n can be selected while shifting one by one as a group of eight.
Electronic scanning in the X-axis direction can be performed. When the electronic scanning is completed, the motor 7M is driven by a command from the CPU 20a, and the arm 7, that is, the array probe 10 is moved by a predetermined sampling pitch YP in the Y-axis direction (mechanical scanning). In this state, electronic scanning by ultrasonic waves in the second row in the X-axis direction is performed in the same manner as described above. By repeating such an operation, ultrasonic scanning of the X-Y plane is performed on the test material 3, and each receiver 24 is scanned during the ultrasonic scanning.
The reflected wave signals received at are sequentially stored at predetermined addresses in the image memory 20b. Based on the data stored in the image memory 20b, an ultrasonic image of the test material 3 by the ultrasonic scanning is displayed on the display device 21. By observing the displayed ultrasonic image, the defect of the test material 3 is checked.

Since the scanning time for one line in the X-axis direction is extremely short, mechanical scanning in the Y-axis direction can be performed without stopping halfway. The number of the group of array transducers to be selected can be arbitrarily set.

The transmission beam focusing circuit 22b, transmission side matrix switch network 22c, pulse generator group 23, preamplifier group 24, reception matrix switch network 25, and reception beam focusing circuits 25 and 26 shown in FIG. The configuration is disclosed in
No. 9654 discloses this.

The conventional ultrasonic inspection apparatus described above can quickly and accurately inspect the inspection material 3 for the presence or absence of a defect. However, in the electronic scanning (scanning in the X-axis direction) of the above-described conventional ultrasonic inspection apparatus, when data sampling is performed at each focal point, a phenomenon occurs in which the signal level varies every time each data sampling is performed. This is shown in FIG. In FIG. 8, the horizontal axis indicates the sampling position in the electronic scanning direction, and the vertical axis indicates the received signal level. As is clear from the figure, the received signal level has a considerably large variation. The present inventors have investigated the causes of such variations, and as a result, it has been found that the main causes are the array probe 10, the pulsar 23 and the receiver 24. This will be described with reference to the drawings.

FIG. 9 is a detailed block diagram of the array probe, the pulsar, and the receiver. FIG at, 10 ₁ to 10 _n denotes each array transducers configuring the array probe 10. As mentioned earlier,
Each array transducer 10 ₁ to 10 _n are pulser 23 ₁ ~ 23 _n,
Receivers 24 _{1 to} 24 _n are connected. A plurality of combinations of the array transducer, the pulsar, the receiver, the conductors connecting them, and the involved parts in the transmission control circuit 22 and the reception control circuit 25 constitute one channel for transmitting and receiving one ultrasonic beam. become. In such a configuration, the sensitivity of each of the array transducers 10 ₁ to 10 _n and each of the pulsars 23 ₁
~ 23 _n of sensitivity, and can not avoid that there is some degree of difference Each of the sensitivity of each receiver 24 ₁ to 24 _n. Therefore, when the three elements of the array transducer, the pulsar, and the receiver have low sensitivity, the reception signal level of the channel when the three elements are connected is considerably reduced, and the sensitivity of the three elements is high. The received signal level of the channels when they are connected to each other considerably increases, and as a result, the received signal level of each channel varies.

FIG. 10 is a diagram of inspecting a defective test material by an ultrasonic inspection device having the above-described variation in received signal, and FIG. 11 is an ultrasonic image of an inspection result in the case shown in FIG. FIG. In FIG. 10, reference numeral 3 denotes a test material, 3f denotes a dent defect portion of the test material 3, and 10 denotes an array probe. In FIG. 11, reference numeral 21a denotes a display surface of the display device 21, A denotes an ultrasonic image of the contour of the test material 3, and 3f 'denotes an ultrasonic image of the defect 3f. G ₁ ~G ₆ is a fringes produced on the result Y-axis direction of the variation of the received signal of each channel in the ultrasonic inspection apparatus. (Actually, many fringes of various widths are generated.) These fringes make it difficult to see the whole image in observing an ultrasonic image, making it difficult to find a defective portion. For example, there is no defective portion and no defect. If the difference in the ultrasonic signal level between the portion and the portion is very small, the influence of the fringe may cause trouble such as the boundary between the two portions being unclear.

As a means to remove such variations,
23 _1-23 It is contemplated that _n or the sensitivity adjustment unit provided in the receiver 24 ₁ to 24 _n to adjust the level of the received signal. This means is possible when the total number n of array transducers is small, but when the total number n is 100 to 200, it takes an extremely long time only by adjusting the sensitivity, and the time can be reduced. Therefore, if the sensitivity adjustment is to be automated, the circuit mounting area becomes enormous, and the control thereof becomes extremely complicated. Further, even if the angle sensitivity adjustment unit is provided, if the array probe is replaced (such replacement is often performed), all sensitivity adjustments must be performed again, and much time and effort are required for each replacement. Takes time. Further, even if the sensitivity adjusting section is provided, the following problem occurs. That is, it is also present in the reception control circuit 25 which is the next stage circuit of the receiver 24 which causes the variation in sensitivity. Since the reception control circuit 25 has a plurality of input / output signal lines, the signal intensity changes depending on which of these signal lines the ultrasonic signal passes. As a result, even if the variation in sensitivity is completely eliminated at the stage of the pulser and the receiver, the variation will remain after passing through the signal line.

Means for solving these problems has been proposed in Japanese Patent Application Laid-Open No. Sho 55-146067. In this means, there is an example in which an ultrasonic inspection device is used for the inspection of the inner wall of a test hole in the ground, for example,
A pseudo borehole such as an aluminum pipe having a smooth inner wall surface is prepared, and sensitivity l _i (i is a channel number) of each channel when an ultrasonic beam is radiated therefrom is sampled.
When conducting an investigation, radiate ultrasonic waves to the inner wall of the ground borehole,
The ratio of the obtained reflected echo intensity m _i (i is the channel number) to the above channel sensitivity l _i is calculated, and the reflected echo n _i (i is the channel number) is adjusted by multiplying the ratio by a constant k. obtain. That is, the following equation is calculated.

n _i = k · m _i / l _i This operation is performed between the same channel numbers.

With such a means, the sensitivity can be surely adjusted without using any troublesome means.

By the way, in the ultrasonic inspection, when the defect is present in the test material, the luminance of the defect is higher or lower than the luminance of the normal part of the test material on the image of the display unit. The luminance of the normal part is usually set to an intermediate value between the minimum value and the maximum value of the luminance. Here, since the ratio (m _i / l _i ) in the above equation is not a value representing the reflection intensity itself, in order to obtain the above-mentioned luminance relationship, the coefficient (k) in the above equation must be calculated by comparing the normal part with the above intermediate value. Must be set to a value. That is, the coefficient (k) is
Internal conditions such as transmission voltage, transmission waveform (wave number), amplification degree of reception, and other factors such as water distance (distance between probe and test material in water), angle between probe and test material, etc. When the target conditions are determined, they are determined so as to have the above-mentioned intermediate value under those conditions.

However, in the ultrasonic inspection, during the inspection, a process of changing the above internal conditions and external conditions is often performed according to the material and shape of the test material or by observing the image displayed on the display unit. is, if such a change was made, in the conventional unit number m _i is changed by the change, even the change in the intermediate value k defined to adapt to other inspection conditions are multiplied Therefore, the change in luminance appears extremely large, causing great confusion in the image and hindering the determination of the presence or absence of a defective portion. For this reason, in the above-mentioned conventional means, every time the internal condition or the external condition is changed, the coefficient (k) is changed according to the content of the change, or the ultrasonic data (l _i ) of the reference material is collected again. This requires a lot of trouble and time.

The object of the present invention is to solve the above-mentioned problems in the prior art, and even if internal conditions or external conditions are changed, it is possible to adjust the sensitivity without any trouble and time corresponding to this, Accordingly, an object of the present invention is to provide an ultrasonic inspection apparatus capable of displaying a clear image of a defective portion and accurately inspecting a test material.

DISCLOSURE OF THE INVENTION An array probe in which a large number of array transducers are arranged in at least one row, and a storage unit for storing ultrasonic data obtained by ultrasonically scanning the surface of a test material with the array probe And an ultrasonic inspection apparatus including a display unit that displays an ultrasonic image based on the data stored in the storage unit.
One means of the present invention is to first perform ultrasonic scanning of a reference material of a uniform material having no defective portion, for example, a bottom surface of a water tank on which a test material is placed, to collect reference data, and average the values thereof. First
Is calculated by the calculating means. Then, when the test material is subjected to ultrasonic scanning, each inspection data obtained by the ultrasonic scanning, the average value, and each of the reference data collected by the same channel as the channel from which each inspection data is sampled. Is multiplied by the second computing means. By this multiplication, correction inspection data obtained when each element has the same sensitivity is obtained. By outputting these corrected inspection data to the display unit, a clear ultrasonic image can be obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a scanner section of an ultrasonic inspection apparatus, and FIG.
FIGS. 3 and 3 are a plan view and a side view, respectively, of the array probe, FIGS. 4 and 5 are explanatory views of the function of the array probe, FIG. 6 is a block diagram of a conventional ultrasonic inspection apparatus, 7 is a more detailed block diagram of FIG. 6, FIG. 8 is a waveform diagram of the received signal, FIG. 9 is a detailed block diagram of each array probe, each pulser, and each receiver, and FIG. 10 is a defect. FIG. 11 is a view showing an ultrasonic image of the test material, FIG. 12 is a block diagram of an ultrasonic inspection apparatus according to the first embodiment of the present invention, FIG. The figure is a cross-sectional view of the water tank, and FIG. 14 is a graph of the reference data.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in further detail with reference to the accompanying drawings.

FIG. 12 is a block diagram of the ultrasonic inspection apparatus according to the first embodiment of the present invention. In the figure, the same reference numerals are given to the same or equivalent parts as those shown in FIGS. 6 and 7, and the description is omitted.
20a 'is a CPU corresponding to the CPU 20a, and has a different processing procedure from that of the CPU 20a. 20e is a memory provided separately from the image memory 20b.

Next, the operation of this embodiment will be described with reference to FIG. 13 and FIG. FIG. 13 is a sectional view of a water tank into which an array probe is inserted. 1 is a water tank, 2 is water put in the water tank 1, and 10 is an array probe, which are shown in FIGS.
The same water tank and array probe as those shown in FIG. 3 and FIG. In this embodiment, a predetermined process (preparation work) is performed before performing an ultrasonic inspection. Hereinafter, this preparation work will be described.

First, the CPU 20a 'uses the array probe 10 to perform an ultrasonic inspection of the test material 3 on the bottom surface (formed flat of an acrylic material) of the water tank 1 on which the test material 3 is not placed. As shown by an arrow in FIG. 13, one line of ultrasonic scanning is performed in the same manner as in the case where the scanning is performed, and the data (A / D converted data, referred to as reference data) is collected. The information is stored in an appropriate storage unit. FIG. 14 is a graph of the reference data, in which the horizontal axis represents the sampling position in the electronic scanning direction and the vertical axis represents the reference data.
_{K 1, K 2, K 3} , ......... K n represents the respective reference data, the graph is represented by connecting these reference data sequentially in a straight line. As is clear from this graph, these reference data are not the same values even though they are obtained by ultrasonically scanning the bottom member (reference material) of the water tank 1 which is made of the same material and is smooth. However, there is variation due to the difference in sensitivity described above.

The CPU 20a 'calculates the average value of these reference data (n pieces) according to the following equation (1), and stores this.

This average value can be regarded as data obtained when the bottom surface of the water tank 1 is subjected to ultrasonic scanning based on the average sensitivity of the entire sensitivity.

Then, CPU 20a 'is reference data _{K 1, K 2, K 3} , ......... K i, ...
... _For each Kn, the ratio (/ K) to the average value obtained by equation (2)
_i ) is calculated, and the values of these ratios are stored in the memory 20e.
The values of these ratios are the inverse of the magnitude of each reference data K _i to the average value of the reference data (K _i /), i.e.. This is the reciprocal of the magnitude of the sensitivity of each channel with respect to the average sensitivity of each channel for collecting data at each sampling point in one line of the electronic scan of the ultrasonic scanning. This completes the preparatory work before the ultrasonic inspection.

It should be noted that even if the amplification factor of the main amplifier 27 changes after the end of this operation, the value of the ratio (/ K _i ) does not change, and it is clear that the ratio always becomes a constant value.

When an ultrasonic inspection is performed on the subject 3, the inspection data at each sampling point is collected in the same manner as in the conventional apparatus, and the collected inspection data is stored in the image memory 20b. Here, of these inspection data, the data of each channel of one line of the electronic scanning are represented by Q ₁ , Q ₂ , Q ₃ ,..., Q _i ,
......... and Q _n. CPU 20a 'multiplies the ratio of the values of the same channel stored in the memory 20e for each of these inspection data Q ₁ to Q _n a (/ K _i) as follows (3).

Since the value Q _i ′ obtained by the equation (3) is a value obtained by multiplying the inspection data Q _i by the reciprocal of the sensitivity at the time of collecting the reference data of the channel, it is equivalent to the inspection data obtained at the average sensitivity. Value. The data Q _i ′ thus corrected by the equation (3) is sequentially replaced with the inspection data Q _i in the image memory 20b every time the calculation of the above equation (3) is completed. In addition,
The calculation of the above equation (3) may be executed within the sampling time interval during electronic scanning, may be executed when sampling for one line of electronic scanning is completed, or all inspection data may be used. It may be executed after sampling. When running this out within the sampling time interval during electronic scanning, inspection data Q _i also connexion it is not necessary to previously stored image memory 20b and, when the test data Q _i are obtained (3) of The operation is performed, and the operation result Q _i ′ is stored in the image memory 20.
In this case, the processing time can be shortened. In this way, all the corrected data is finally stored in the image memory 20b.

Here, for example, when the subject 3 has no defect,
All data in the image memory 20b is equal to the average value of all inspection data, and when there is a defect, the data of other parts except the defective portion is equal to the average value, and only the defective portion is equal to the average value. Will be different values. Therefore, when the display device 21 performs display on the basis of the corrected data, if there is a defective portion in the subject 3, the defective portion is clearly distinguished from the others and displayed. .

Thus, in this embodiment, the ratio of the ultrasound scan data average value and their respective data K _i of the pre-reference material value (/ K
_i ) is obtained for each channel, and at the time of the ultrasonic inspection, the inspection data of each channel is multiplied by the value of the ratio in the channel to obtain correction data. Even if there is variation, a stripe pattern as shown in FIG. 11 does not occur,
Defective parts can be easily found, and defective parts can be clearly distinguished from other parts and displayed.

Further, as a means for correcting the above-described variation in sensitivity, a reference material which is completely the same as the subject and has no defect is prepared, and ultrasonic scanning data (reference data) of the reference material is obtained from the test data of the subject. Means for reducing are conceivable. However, this means needs to store the reference data of all sampling points, has a problem that the memory capacity is large, and is effective when a large number of specimens having the same shape are examined. Thickness, examination position on the subject,
Whenever the setting conditions such as the gain of the receiver change, the reference data must be changed according to the change each time, and the change requires a lot of trouble and time. On the other hand, in the present embodiment, the reference data only needs to be the number of samplings for one line of electronic scanning, and the memory capacity is small. Further, in the present embodiment, the inspection data Q _i is multiplied by the ratio (/ K _i ) of the average value and the reference data to obtain the correction data Q _{i.
Although i} ′ is obtained, the above ratio (/ K _i ) is a value that is not affected by the conditions on the subject side or the test apparatus side, and therefore is compared with the apparatus described in the above-mentioned JP-A-55-146067. Thus, there is no need to change the constant k in accordance with the change of the inspection condition or to re-collect the data l _i using the reference material, so that the inspection efficiency is remarkably improved.

In the above description of the embodiment, an example is described in which the bottom surface of the water tank is used as the reference material. However, the present invention is not limited to this, and any material can be used as long as the material is uniform. Further, the example in which the ratio value of the memory 20e is stored has been described, but the reference data and their average value may be stored. In this case, the calculation of the correction data needs to be performed by taking out three data of the inspection data, the reference data and the average value, but such calculation processing can be sufficiently performed within the sampling time interval. it can. Further, in the present embodiment, an example has been described in which the memory 20e is used to store the value of the ratio. However, if there is a storage location in the image memory 20b, the memory 20e becomes unnecessary.
Alternatively, an array probe having a configuration in which array transducers are arranged in a matrix may be used. In this case, the number of reference data matches the number of all channels of the ultrasonic beam.

INDUSTRIAL APPLICABILITY As described above, the ultrasonic inspection apparatus according to the present invention can be applied to any type of ultrasonic inspection apparatus using an array transducer.

Claims (3)

(57) [Claims] 1. An array probe (10) comprising a large number of array transducers (10 ₁ to 10 _n ) arranged in at least one row, and a material (3) to be inspected (3) by the array probe (10). Storage unit for storing ultrasonic data obtained by ultrasonically scanning the surface (20b)
And a display unit (21) for displaying an ultrasonic image based on the data stored in the storage unit (20b). First calculating means for calculating an average value of reference data obtained by ultrasonic scanning, and each inspection data, the average value, and each of the inspection data obtained by ultrasonically scanning the test material. Multiplying the reciprocals of the respective reference data by each other
An ultrasonic inspection apparatus, comprising: a calculating means of (1), and an output means for outputting a calculation result of the second calculating means to the display section (21). 2. The ultrasonic inspection apparatus according to claim 1, wherein the operation by the second operation means is executed every time the inspection data is sampled. 3. The method according to claim 1, wherein the multiplication of the average value and the reciprocal of the reference data in the calculation by the second calculation means is performed before the sampling of each of the test data. Ultrasonic inspection equipment.