JPH0580034A - Ultrasonic flaw detector - Google Patents

Abstract

PURPOSE:To achieve improvements in a B mode color display and a color display by sampling and quantization signals of a defect echo reflected from a defect in a material to be inspected. CONSTITUTION:A defect echo which is reflected from a defect in a material by using an ultrasonic wave to be obtained with linear amplification thereof through a receiving circuit is stored into a line memory 9 once after the sampling and quantization thereof. The defect echo undergoes color classification, for example, by red, green, white and blue with a color discriminator circuit 10 comprising a comparator using a logarithmic conversion value of an echo level as threshold and one screen of frame images are formed to perform a B mode color display. Thus, color increases in a defect display thereby allowing the detection of the size of the defect in details and the defect echo is subjected to no level conversion thereby enabling color display quickly and economically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention shows, for example, a defect echo reflected by an internal defect by scanning a probe with a probe and displaying the defect echo in color in B mode. The present invention relates to an ultrasonic flaw detector for detecting defects, and particularly to improvement of color display.

[0002]

2. Description of the Related Art FIG. 6 is a cross-sectional view showing an example of a defect in a test material, 4 is a probe, 19 is a test material, and 20 is a defect. There are a plurality of defects 20 of different sizes and different sizes. The probe 4 is brought into contact with the surface of the material 19 to be inspected, and internal defects are detected by transmitting and receiving ultrasonic pulses.

FIG. 7 is an explanatory view of the defect echo color classification in the conventional A mode display, and FIG. 7A is the A mode with the first defect echo color classification, the ultrasonic wave propagation distance on the horizontal axis, and the defect echo level on the vertical axis. In the display, the defect echo is color-divided by four colors of red, green, white, and blue (background) at equal level intervals. Indicates the first defect echo. Since the first defect echo has a high echo level, it is related to all the color segments of red, green, white and blue (background). FIG. 7b shows the color classification of the second defect echo, indicates the second defect echo, the second defect echo in the A mode display is green according to the echo level,
It is related to white and blue (background). FIG. 7c shows the color segment of the third defect echo, is the third defect echo, and the third defect echo in the A mode display is related to the color segments white and blue (background) because the echo level is small.

FIG. 8 is a B-mode figure showing an example of conventional defect display, B-type scanning, that is, the defect detection is performed while the probe 4 is moving on the material to be inspected 19, and the flaw detection position is represented by the horizontal axis and ultrasonic wave propagation. The defect echo is displayed in the B mode with the distance of as the vertical axis.
The color of each defect echo is discriminated by the threshold values of red, green, white and blue (background) according to the level thereof.

The first defect echo is displayed in four colors: red at the center, green at the periphery, white at the periphery and blue at the background. The second defect echo is green at the center and white at the periphery. The background is displayed in three colors of blue, the third defect echo is displayed in white, and the background of two defects is displayed in blue. Defects 20 in the material 19 to be inspected are determined in color type and display size, and are displayed in color at positions corresponding to the defects 20 in the material to be inspected 19.

[0006]

In the conventional ultrasonic flaw detector as described above, ultrasonic waves are radiated toward the material to be inspected 19, and the defect echo reflected from the defect 20 in the material to be inspected 19 is a straight line. It is amplified and is normally displayed by the A mode at an echo level proportional to the size of the defect 20 at a position corresponding to the distance of ultrasonic wave propagation. The defect evaluation is based on the ratio of the mutual level of the defect echo to the bottom echo of the test material 19.

When the defect echo is color-displayed in the B mode by performing color division by thresholds having equal level intervals, the defect 20 has four defect echoes of red, green, white and blue depending on the size thereof. The color and the second defect echo are displayed in three colors of green, white and blue, and the third defect echo is displayed in two colors of white and blue.

However, in order to widen the dynamic range of the color segment of the defect 20, the defect echo is subjected to logarithmic conversion of the echo level through a logarithmic amplifier and the color is discriminated by the threshold value of the color segment. The size of the defect is detected in more detail and defect evaluation can be performed accurately. However, since the logarithmic amplifier is used, the cost is increased as compared with the linear amplification. Further, since the defect echo level is logarithmically converted, the echo level displayed in the A mode is not proportional to the size of the defect 20, so that the defect cannot be evaluated correctly.

Further, if logarithmic amplification is performed, the influence of an interfering signal such as noise becomes remarkable, which interferes with defect detection. Further, when the color classification is performed based on the non-linear characteristic other than the logarithmic function, there is a problem that it cannot be performed quickly and easily because an amplifier having these functional characteristics is used.

The present invention has been made to solve the above problems, and linear amplification of defect echoes and threshold setting of color classification by an arbitrary function can be performed quickly and at low cost, and defect evaluation based on color display can be performed. It is an object of the present invention to obtain an ultrasonic flaw detector which can be correctly performed and whose echo level in A mode display is proportional to the size of a defect.

[0011]

An ultrasonic flaw detector according to the present invention classifies a line memory for storing a quantized defect echo after sampling and a color classification for the defect echo at a level according to a predetermined function. A setter that sets the threshold value for each color, a color discrimination circuit that color-codes the defect echo by comparing the threshold value for each color that distinguishes the signal read from the line memory, and the color-coded signal A frame memory is provided for converting a level into a display signal and sequentially storing it to form a frame image for one screen.

[0012]

In the present invention, the defect echo reflected from the defect in the material to be inspected is sampled and quantized through the receiving circuit using the linear amplifier, and is temporarily stored in the line memory. Since the defect echo is classified into red, green, white, and blue (background) colors, a color discrimination circuit including a plurality of comparators using a setter that uses the logarithmic conversion value of the echo level as a threshold value for each color is used. Add.

At this time, when the logarithmically converted threshold value is used, the division range of each color is non-linear and is red, green, white, blue (background).
The defect echoes become smaller in order, and the defect echoes can be classified in detail over a wide level range. The color-separated defect echo is stored in the frame memory that forms a frame image for one screen through the color encoder, and the color of the defect display increases, and it is possible to appropriately color-separate from minute defects to large defects and clearly display it on the digital display. Is displayed.

Since a linear amplifier is provided in the receiving circuit and a function set value of the echo level is displayed in color in the setter as a threshold value, color display in various color sections can be performed quickly and economically only by changing the threshold value. it can. Further, since the defect echo is displayed in the A mode, the defect can be correctly evaluated by comparison with the bottom echo. Furthermore, since no non-linear amplifier is used in the receiving circuit, interference of noise and interfering signals is suppressed and defect detection can be facilitated.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram of an essential part showing an embodiment of the present invention, 7 is an A / D conversion circuit, 8 is a memory controller for designating address designation of data to be stored in a memory, and writing and reading of data, and 9 is a memory controller. A line memory, 10 is a color discriminating circuit for color-distributing a defect echo, 11 is a setter for setting a threshold value of each color for color discrimination, 12 is a color encoder for converting a color-discriminated signal into a color display signal, 13
Is a frame memory that forms a frame image for one screen,
Reference numeral 15 is a digital type display, 16 is a first comparator for identifying the color red, 17 is a second comparator for identifying the color green, and 18 is a third comparator for identifying the color white.

In the ultrasonic flaw detector constructed as described above, the defect echo reflected from the defect in the material to be inspected by the ultrasonic pulse radiated to the material to be inspected is sampled after A / It is quantized by the D conversion circuit 7 and temporarily stored in the line memory 9 according to a command from the memory controller 8.
The defect echo read from the line memory 9 is, for example, red,
In order to classify into green, white, and blue (background), it is added to the color discriminating circuit 10 including a comparator provided with three kinds of thresholds individually.

FIG. 2 is a correlation diagram between a defect echo level and a threshold value, shows a logarithmic function based on a polygonal line approximation, where the color segment is the ordinate and the defect echo level is the abscissa, the color segment and the logarithm at equal level intervals. From the intersection with the function, threshold value 1 ... color segment red, threshold value 2 ... color segment green, threshold value 3 ... color segment white, and hereinafter background ... color segment blue are determined.

FIG. 3 is an explanatory view of the defect echo color classification in the A mode display, and FIG. 3a is the color classification of the first defect echo, FIG.
FIG. 3b shows the color classification of the second defect echo, and FIG. 3c shows the color classification of the third defect echo. By using the logarithmic conversion value of the echo level as the threshold value, the display color of the first defect echo and the second defect echo is displayed. Are four colors of red, green, white, and blue (background), and the display colors of the third defect echo are green, white, and
Related to blue (background).

The threshold value corresponding to each color segment is set by the setter 11
Set to. The signal corresponding to the color segment red is output from the first comparator 16 associated with the threshold 1, and the second comparator 1 associated with the threshold 2.
7 outputs a color-corresponding green equivalent signal, and a third comparator 18 associated with the threshold value 3 outputs a color-corresponding white equivalent signal. The signal corresponding to each color segment is added to the color encoder 12 and signal conversion corresponding to the display color is performed.

The output signal of the color encoder 12 is sequentially stored in the frame memory 13 in response to the addresses and write commands in the X-axis and Y-axis directions from the memory controller 8, forms a frame image for one screen, and is then read out. Are displayed in color on the display unit 15. At this time, since the level of the defect echo is not converted by a logarithmic function or the like, it is directly proportional to the size of the defect in the test material.

FIG. 4 shows a B-mode figure showing an example of defect display, a flaw detection position of a material to be inspected, and a position corresponding to the ultrasonic wave propagation distance. And the second defect echo is red, green,
The four colors of white and blue (background) and the third defect echo are displayed in three colors of green, white, and blue (background) in color according to the size of the defect. Since the display color of the defect is increased, the size of the defect can be accurately detected. When the color classification is performed by a non-linear function other than the logarithmic function, the threshold value is determined by using the non-linear function, and the color display of the defect echo can be similarly performed.

FIG. 5 is a block diagram showing an example of the ultrasonic flaw detector according to the present invention, 4, 7, 8 , 9, 10 , 11, 11.
2, 13, 15, 19 and 20 are the same as those in the above embodiment, 1 is a clock circuit for generating a time reference pulse, 2
Is a timing circuit for generating a timing signal for ultrasonic radiation, 3 is a pulse circuit, 6 is a sample hold circuit for periodically sampling analog signals and holding sample values, and 14 is B
The drive circuit which controls mode display is shown.

In the ultrasonic flaw detector constructed as described above, the time series of reflection from the defect 20 in the material 19 to be inspected by the ultrasonic waves emitted in synchronization with the clock of the clock circuit 1 of the clock circuit 1. The analog signal of 1 is applied to the sample hold circuit 6 via the receiving circuit 5. The analog signal is sampled at the clock cycle, and the sampled value is A
It is quantized by the / D conversion circuit 7 and temporarily stored in the line memory 9 according to a command from the memory controller 8.

Next, the quantized signal of the defect echo is applied to the color discrimination circuit 10 and compared with each color threshold value by the setter 11 by the comparator to obtain color signals such as red, green, white and blue (background).
To be distinguished. The color-separated defect echoes are sequentially stored in the frame memory 13 for each of red, green, and white through the color encoder 12 to form a frame image for one screen. The image signal is displayed on the display 15 by the drive circuit 14 for each color. As the display unit 15, for example, a liquid crystal display including a matrix type LCD whose operation is controlled on a pixel-by-pixel basis is used to perform digital display.

The defect 20 in the material 19 to be inspected is color-displayed in the B mode in which the color classification and the display size are determined by its size. In addition, the color display is red, green, white, and blue (background).
In order to perform multi-color other than,
This can be achieved by increasing the number of gradations for each color of green and white and controlling this.

In the present invention, the desired color display can be easily realized by not performing the function conversion of the defect echo level in the receiving circuit 5 and setting the threshold value to a value according to the color classification. Since the color of defect display is increased, it is possible to clearly display by appropriately color-dividing from small defects to large defects. Since the non-linear amplifier is not used in the receiving circuit 5, the cost is reduced, and the echo level is proportional to the size of the defect.
The size of the defect can be correctly evaluated in the A mode display.

[0027]

As described above, according to the present invention, a setter for setting a threshold value for color-distributing a quantized defect echo after sampling and a color for color-defining a defect echo by the threshold value. With a simple structure that includes a discrimination circuit and a frame memory that forms an image for one screen, the color of defect display is increased, and it is possible to clearly display by appropriately color-coding from small defects to large defects. Since the receiving circuit does not perform function conversion of the defect echo level, color display can be easily performed. Moreover, since it does not use a logarithmic amplifier, it can be economically performed. The echo level is proportional to the size of the defect and has the effect that the defect can be evaluated correctly.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts showing an embodiment of the present invention.

FIG. 2 is a correlation diagram between a defect echo level and a threshold value.

FIG. 3 is an explanatory view of defect echo color classification in A mode display. A is a first defect echo color classification, b is a second defect echo color classification, and c is a third defect echo color classification.

FIG. 4 is a B-mode figure showing an example of defect display.

FIG. 5 is a block diagram showing an example of an ultrasonic flaw detector according to the present invention.

FIG. 6 is a cross-sectional view showing an example of a defect in a test material.

FIG. 7 is an explanatory view of defect echo color classification in a conventional A-mode display: a is a first defect echo color classification, b is a second defect echo color classification, and c is a third defect echo color classification.

FIG. 8 is a B-mode graphic showing an example of a conventional defect display.

[Explanation of symbols]

7 A / D conversion circuit 8 Memory controller 9 Line memory 10 Color discrimination circuit 11 Setting device 12 Color encoder 13 Frame memory 16 First comparator 17 Second comparator 18 Third comparator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Inoue 2-16-46 Minami Kamata, Ota-ku, Tokyo Within Tokimetsuku Co., Ltd. (72) Kouji Saito 2-16-46 Minami-Kamata, Ota-ku, Tokyo Stock company Tokimetuku

Claims (3)

[Claims] 1. An ultrasonic flaw detector for displaying a time-series defect echo reflected from a defect in a material to be inspected in discrete time, quantizing it, and color-displaying it in B mode on a digital display. , A line memory for storing the quantized defect echo after sampling, a setter for setting a threshold value for each color in order to color-code the defect echo at a level according to a predetermined function, and read from the line memory A color discriminating circuit for color-distributing the defective echo by comparing the threshold value for each color for discriminating the divided signal, and level-converting the color-divided signal into a color display signal and sequentially storing the frame for one screen. An ultrasonic flaw detector, comprising: a frame memory for forming an image. 2. The ultrasonic flaw detector according to claim 1, wherein the function is a logarithmic function. 3. The ultrasonic flaw detector according to claim 1, wherein the color classification is four colors of red, green, white and blue.