JP6933497B2 - X-ray inspection equipment - Google Patents

Description

In the present invention, an object to be inspected filled with a liquid-containing content is irradiated with X-rays generated by an X-ray generator, and the X-rays transmitted through the object to be inspected are detected by an X-ray detector. This relates to an X-ray inspection device that inspects the contents of the contents.

As a conventional X-ray inspection apparatus of this type, the one described in Patent Document 1 is known. In the case described in Patent Document 1, the average value of the liquid level point data representing the liquid level position of the contents is calculated as a virtual liquid level, and the content is inspected depending on whether or not the virtual liquid level is within a predetermined range. doing.

Japanese Unexamined Patent Publication No. 7-0275994

The one described in Patent Document 1 is effective against waviness of only the liquid level of the contents due to vibration, but when the container itself moves up and down, the level of the liquid level cannot be inspected correctly. ..

To solve this problem, it is possible to correctly inspect even if the container itself moves up and down by taking an image of the entire container from the lower end to the level of the liquid level and inspecting the internal volume. become.

However, when inspecting the content of a container such as a tall bottle, the X-ray emission angle in the height direction widens, causing a difference in the amount of X-ray transmission between the bottom surface of the container and the liquid level. Therefore, there is a problem that the detection accuracy of the content is lowered.

Therefore, the present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide an X-ray inspection apparatus capable of improving the inspection accuracy of the content of an object to be inspected.

The X-ray inspection apparatus according to the present invention includes an X-ray generator that generates X-rays and an X-ray detector that detects X-rays, and forms a transport path through which the object to be inspected passes in the horizontal direction. The X-ray generator and the X-ray detector are arranged so that the X-ray detector detects the height direction from the transport surface of the conveyor, and the object to be inspected is liquid in the container. An X-ray inspection apparatus filled with contents containing the above, wherein the upper surface of the object to be inspected and the liquid level of the contents in an X-ray image based on X-rays detected by the X-ray detector. Based on the inspection target area extraction unit that extracts the inspection target area of a predetermined size including the empty package area in the container and the pixel density of the X-ray image integrated in the inspection target area. It is characterized by including a determination unit for determining whether or not the content of the object to be inspected is normal.

With this configuration, by determining the concentration integrated value (or concentration average value) that integrates the concentration in the inspection target area, the influence of vertical fluctuation of the object to be inspected and the inclination of the contents due to transportation is reduced, and the inspected object is inspected. Since the fluctuation of the content of the entire object can be detected correctly, the inspection accuracy of the content of the object to be inspected can be improved.

In the X-ray inspection apparatus according to the present invention, the inspection target area extraction unit is characterized in that the inspection target area is extracted based on the length from the upper surface of the object to be inspected specified in advance.

With this configuration, it is possible to inspect the content in the inspection target area with the minimum height that takes into account fluctuations in the height direction of the contents of the normal product, so detection by spreading X-rays in the height direction is possible. The decrease in accuracy can be minimized.

In the X-ray inspection apparatus according to the present invention, the inspection target area extraction unit has an outer shape extraction unit that extracts the outer shape of the object to be inspected, and extracts an inspection target area having a predetermined size in the outer shape. It is characterized by.

With this configuration, it is less likely to be affected by the atmosphere outside the object to be inspected, and the inspection accuracy can be improved more stably.

The present invention can provide an X-ray inspection apparatus capable of improving the inspection accuracy of the content of an object to be inspected.

It is a perspective view of the X-ray inspection apparatus which concerns on one Embodiment of this invention. It is sectional drawing in the cross section orthogonal to the transport direction of the X-ray inspection apparatus which concerns on one Embodiment of this invention. It is a flowchart explaining the operation of the X-ray inspection apparatus which concerns on one Embodiment of this invention. It is a figure explaining the method of extracting the inspection target area in the X-ray inspection apparatus which concerns on one Embodiment of this invention. (A) and (b) are diagrams for explaining another example of the method of extracting the inspection target area in the X-ray inspection apparatus according to the embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the configuration will be described.

In FIG. 1, the X-ray inspection device 1 includes a housing 4. The housing 4 is incorporated in the conveyor 2 that conveys the object W to be inspected. The upper space of the conveyor 2 forms a transport path 3 through which the object W to be inspected passes in the horizontal direction. This embodiment illustrates the case where the object W to be inspected is a beverage bottle.

The conveyor 2 is a part of the production equipment of the object W to be inspected, and is configured separately from the X-ray inspection device 1. This embodiment illustrates the case where the conveyor 2 is composed of a top chain conveyor. The top chain conveyor is an endless chain provided with a plurality of plates, and the object W to be inspected is conveyed on the upper surface of the plates serving as the conveying member 21 of the conveyor 2.

As described above, the X-ray inspection device 1 is a built-in X-ray inspection device incorporated in a separate conveyor 2, and is a top chain conveyor, a belt conveyor, or the like often used for bottle transportation as shown in FIG. It is incorporated into an existing conveyor that transports the object W to be inspected in the horizontal direction. In the case of transporting the object W to be inspected by the belt conveyor, the belt serves as the transport member 21. Further, the conveyor 2 may be integrally configured with the X-ray inspection device 1.

The housing 4 is formed with an opening 7 into which the object W to be inspected is carried in and an opening 8 in which the object W to be inspected is carried out. The conveyor 2 penetrates the housing 4 through the openings 7 and 8. The housing 4 is provided with a shielding cover 16 made of a metal capable of shielding X-rays such as stainless steel around the openings 7 and 8, and the shielding cover 16 is provided with X-rays from the openings 7 and 8 to the outside. Leakage is prevented.

A guide member 61 is provided above the conveyor 2, and the guide member 61 guides the object W to be inspected so that the object W to be inspected is conveyed at the center position in the width direction on the conveyor 2. .. A total of four guide members 61 are provided on the left and right sides so as to sandwich the object W to be inspected in the width direction.

The guide member 61 is divided so as not to enter the X-ray irradiation field of the X-ray generator 9. The guide member 61 may be made of a material having a high X-ray transmittance and may be continuously provided so as to penetrate from the opening 7 to the opening 8 like the conveyor 2.

In FIG. 2, the X-ray inspection device 1 includes an X-ray generator 9 that generates X-rays, an X-ray detector 10 that detects X-rays, and a comprehensive control unit 40. The X-ray generator 9, the X-ray detector 10, and the comprehensive control unit 40 are housed inside the housing 4 (see FIG. 1).

The X-ray generator 9 and the X-ray detector 10 are arranged so as to face each other in the width direction of the conveyor 2 so as to sandwich the transport path 3 on which the object W to be inspected on the conveyor 2 is conveyed. That is, the X-ray generator 9 and the X-ray detector 10 are arranged so as to face each other with the conveyor 2 sandwiched in the width direction.

The X-ray generator 9 generates X-rays by irradiating the target of the anode with an electron beam from the cathode of an X-ray tube (not shown) provided inside the X-ray generator 9, and the generated X-rays are formed into a substantially triangular shape by slits (not shown). It is designed to be molded into the shape of a screen. Further, the X-ray generator 9 irradiates the X-rays formed in the screen-shaped X-ray irradiation field toward the X-ray detector 10 so as to cross the transport path 3 on the conveyor 2 in the width direction. It has become.

Therefore, the X-rays generated from the X-ray generator 9 spread radially with the X-ray generator 9 as a point light source. Therefore, X-rays are irradiated substantially parallel to the transport surface 2A in the vicinity of the transport surface 2A, which is the upper surface of the conveyor 2, but X-rays are radiated at a larger angle at a position farther from the transport surface 2A.

In the present embodiment, the object W to be inspected is a bottle-shaped container W1 long in the vertical direction filled with the content W2. Therefore, at the liquid level position of the content W2 near the upper end of the object W to be inspected, X-rays are obliquely irradiated at an angle larger than the bottom portion of the object W to be inspected.

Above the contents of W 2 in the container W 1, empty packet region W3 is formed is a region other than contents W2. The blank region W3 is a region between the upper surface of the object W to be inspected and the liquid level of the content W2, and is composed of air, nitrogen filled for quality maintenance, or the like.

The X-ray detector 10 includes an X-ray line sensor in which a plurality of detection elements 10A are arranged in a line. The detection element 10A of the X-ray detector 10 includes a photodiode (not shown) and a scintillator (not shown) provided on the photodiode. X-rays are converted into light by the scintillator, and this light is detected by the photodiode. ing.

N of the plurality of detection elements 10A of the X-ray detector 10 are arranged perpendicular to the upper surface of the conveyor 2. The data output from the detection element 10A at the lower end of the X-ray detector 10 corresponds to the image of the first pixel at the lower end of the X-ray image.

Similarly, the data output from the nth detection element 10A from the lower end of the X-ray detector 10 corresponds to the nth pixel image from the lower end of the X-ray image. Although the position of the guide member 61 is shown by a broken line in FIG. 2, the guide member 61 does not enter the X-ray irradiation field of the X-ray generator 9.

The X-ray detector 10 configured in this way is an X-ray image corresponding to the amount of X-rays (detection level) transmitted through the X-ray detector W when the object W to be inspected passes through the X-ray detector 10. Is output. The X-ray detector 10 includes an A / D conversion unit (not shown), and the A / D conversion unit converts the luminance value data from the photodiode into digital data.

The data output from the A / D conversion unit may be an X-ray image (bright and dark image) represented by light and dark depending on the brightness value, or a density value obtained by converting the brightness value to a desired density. It may be an X-ray image (shade image) represented by light and shade. In this embodiment, the X-ray image output from the A / D conversion unit of the X-ray detector 10 is a shade image in which the detection level is represented by shades.

In the present embodiment, the X-ray generator 9 is preliminarily adjusted by the installation work so that the X-ray irradiation field is above the conveyor 2. Further, the position of the X-ray detector 10 is adjusted in advance by the installation work so that the lower end portion of the X-ray detector 10 is substantially the same height as the upper surface of the conveyor 2.

The X-ray inspection device 1 includes a display unit 5, a setting operation unit 45, and a comprehensive control unit 40.

The display unit 5 is composed of a flat display or the like, and outputs a display to the user. The display unit 5 is designed to display an image such as an inspection result by the comprehensive control unit 40.

Further, the display unit 5 displays the quality determination result of the object W to be inspected with characters or symbols such as "OK" and "NG". In addition, the display unit 5 displays statistical values such as the total number of inspections, the number of non-defective products, and the total number of NGs.

The display content and display mode of the display unit 5 are determined based on a default setting or a request from the setting operation unit 45 by a predetermined key operation.

The setting operation unit 45 inputs settings such as various parameters to the general control unit 40. The setting operation unit 45 is composed of a plurality of keys, switches, and the like operated by the user, and inputs settings and inputs of various parameters and the like to the comprehensive control unit 40. In the present embodiment, the display unit 5 and the setting operation unit 45 are integrated as a touch panel type display and are arranged on the upper front surface of the housing 4.

The comprehensive control unit 40 includes an X-ray image storage unit 42, an image processing unit 43, a determination unit 44, and a control unit 46.

The X-ray image storage unit 42 temporarily stores the X-ray image received from the X-ray detector 10. That is, the X-ray image storage unit 42 functions as a buffer memory for the X-ray image.

The image processing unit 43 applies various image processing algorithms and the like to the X-ray image read from the X-ray image storage unit 42 to perform image processing. Here, the image processing algorithm is composed of a combination of a plurality of image processing filters.

The determination unit 44 inspects the content of the object W to be inspected with respect to the X-ray image image-processed by the image processing unit 43. The content is the amount (volume) of the content W2 of the object W to be inspected, and is also called the amount of flavor.

The control unit 46 has a memory as a storage area or a work area for the CPU and the control program, and controls the entire X-ray inspection device 1. The control content of the control unit 46 includes control of the display content and display form of the display unit 5.

In the present embodiment, the image processing unit 43 is provided with an inspection target area extraction unit 43A. The inspection target area extraction unit 43A includes a predetermined blank region W3 between the upper surface of the object to be inspected W and the liquid level of the content W2 in the X-ray image based on the X-ray detected by the X-ray detector 10. Extract the size of the inspection target area. Then, the determination unit 44 determines whether or not the content of the object W to be inspected is normal based on the concentration accumulated in the inspection target region.

The determination unit 44 determines whether or not the content of the object W to be inspected is normal with respect to the X-ray image image-processed by the image processing unit 43.

Next, the operation will be described. As shown in the flowchart of FIG. 3, the X-ray inspection apparatus 1 captures an X-ray image (step S1). Here, the X-ray image shown in FIG. 4 is captured. In this X-ray image, a non-defective product having a positive amount of the content W2 and a-NG product having a small amount of the content W2 are shown side by side.

This X-ray image includes a region due to reflection of the conveyor member 21, a background region, and a region of the object W to be inspected. The region of the object W to be inspected includes the region of the container W1, the region of the contents W2, and the region of the blank region W3. The region of the blank region W3 includes a region W3A based on X-rays that has passed obliquely through the liquid surface of the content W2.

In this X-ray image, the area due to the reflection of the conveyor member 21 has the highest density, and the background area has the lowest density. Further, the region of the object W to be inspected is a concentration value between the region of the transport member 21 and the background region.

Further, in the region of the object to be inspected W, the region of the content W2 has the highest concentration, and the region other than the region W3A in the blank region W3 has the lowest concentration. Further, the concentrations of the region of the container W1 and the region of the region W3A are the same, and the concentration value is lower than that of the region of the content W2.

Next, the X-ray inspection apparatus 1 extracts the upper surface of the object W to be inspected based on the density threshold value in this X-ray image (step S2). Here, the upper surface of the container W1 is extracted as the upper surface of the object W to be inspected.

Next, the X-ray inspection apparatus 1 extracts an inspection target area by counting pixels from the upper surface of the object W to be inspected downward as described later with reference to FIGS. 4 and 5 (step S3). ..

Next, the concentration in the inspection target area is integrated to calculate the concentration integrated value (step S4).

Next, the amount of the content is determined based on the calculated concentration integrated value and the determination limit (step S5).

As a specific method of the above operation, there is a method of using an inspection target area including a rectangular background specified by a preset operation.

Specifically, as shown in FIG. 4, the length from the upper surface to the lower side of the object W to be inspected is designated in advance as the height (h1) by the setting operation. The area S (= h1xW) of the rectangular inspection target area having the height (h1) and the width (W) coincides with the area (number of pixels) of the area at the time of setting. Therefore, it depends on whether or not the density integration value in the inspection target area (the number of pixels in the inspection target area) is within the allowable range specified corresponding to the value obtained by integrating the density in the area at the time of setting. The content of the inspection object W can be inspected.

In this method, the background is included in the concentration integration, and the density of the background region is almost nonexistent. , It is preferable to carry out when there is a margin in the inspection accuracy of the content.

Further, as a specific method of the above operation, there is a method in which the inside of the outer shape of the object W to be inspected, which does not include the background, is set as the inspection target area.

Specifically, as shown in FIGS. 5 (a) and 5 (b), first, the inspection target area is extracted based on the height (h2) specified at the time of setting and the outer shape (the portion surrounded by the thick line). do. This outer shape can be obtained by separating the inspected object W from the background at a predetermined threshold value and then further separating the outer shape from the inspected object W.

Then, the inspection target area is adjusted so that the area S of the extracted inspection target area matches the area (number of pixels) of the area designated at the time of setting. By doing so, the concentration integrated value in the inspection target area of the adjusted fixed area is used, and the content of the object W to be inspected is inspected depending on whether or not this concentration integrated value is within the specified allowable range. be able to.

Here, for the concentration integrated value in the adjusted fixed area to be inspected, for example, the area of the height (h2) from the upper surface specified at the time of setting obtained from the outer shape is set as the tentative inspection target area, and this tentative inspection target. The lower bottom of the provisional inspection target area is adjusted by the difference between the area S of the area and the area of the area specified at the time of setting to obtain an inspection target area that matches the area of the area specified at the time of setting. Then, the concentration in the inspection target area is added to obtain the integrated concentration value. Further, with reference to the upstream side of the upper surface of the object W to be inspected on the X-ray image, the density of the X-ray image is added while adding the density until the number of pixels specified at the time of setting is matched with the transport direction in the outer shape and downward. The pixel may be scanned to extract the inspection target area and at the same time obtain the density integration value.

As another method, the content of the object W to be inspected is inspected depending on whether the height (h2) specified at the time of setting and the concentration average value of the region specified from the outer shape are within the permissible range. It may be. In this case, even if the height (h2) and the area S of the region specified from the outer shape vary, the content of the object W to be inspected can be inspected without being affected by the variation by using the average concentration value. This makes it unnecessary to make fine adjustments to the inspection target area to be compared.

As described above, in the X-ray inspection apparatus 1 of the present embodiment, the inspection target area extraction unit 43A is the upper surface and the contents of the inspected object W in the X-ray image based on the X-ray detected by the X-ray detector 10. An inspection target region having a predetermined size including the empty inclusion region W3 between the liquid level of W2 and the liquid level is extracted. Then, the determination unit 44 determines whether or not the content of the object W to be inspected is normal based on the concentration accumulated in the inspection target region.

Here, comparing the concentration integrated values in the inspection target area corresponds to comparing the composition ratio of the empty package amount and the content volume in the inspection target area. Therefore, for example, even if the X-ray image in which the object W to be inspected is tilted and the content is expanded, the integrated value of the density with respect to the content and the integrated value of the density in the X-ray image with the normal content are the same. It will be the same within the area. However, if the total content deviates from the predetermined amount, the composition ratio of the empty package amount and the content will also change according to the change.

Therefore, as described above, by determining the concentration integrated value (or the concentration average value) obtained by integrating the concentrations in the inspection target area, the influence of the vertical fluctuation of the object W to be inspected and the inclination of the content W2 due to the transportation can be affected. It can be reduced and the accuracy of the content inspection can be improved by correctly detecting the fluctuation of the content of the entire W to be inspected.

Further, in the X-ray inspection apparatus 1 of the present embodiment, the inspection target area extraction unit 43A extracts the inspection target area based on the length from the upper surface of the inspected object W designated in advance.

With this configuration, it is possible to inspect the content in the inspection target area of the minimum height considering the fluctuation of the contents W2 of the normal product in the height direction, so that the X-ray spreads in the height direction. The decrease in detection accuracy can be minimized.

Further, in the X-ray inspection apparatus 1 of the present embodiment, the inspection target area extraction unit 43A has an outer shape extraction unit 43B that extracts the outer shape of the object W to be inspected, and has an inspection target area of a predetermined size in the outer shape. Is extracted.

With this configuration, it is less likely to be affected by the atmosphere outside the object to be inspected, and the inspection accuracy can be improved more stably.

As described above, the X-ray inspection apparatus according to the present invention has the effect of improving the inspection accuracy of the content of the object to be inspected, and emits X-rays irradiated from the X-ray generator and transmitted through the object to be inspected. It is useful as an X-ray inspection device that detects foreign matter by detecting it with an X-ray detector.

1 X-ray inspection device 2 Conveyor 5 Display 9 X-ray generator 10 X-ray detector 43A Inspection target area extraction unit 43B External shape extraction unit W Inspected object W1 Container W2 Contents W3 Blank area

Claims (3)

An X-ray generator (9) that generates X-rays and
Equipped with an X-ray detector (10) for detecting X-rays,
The X-ray detector detects the height direction from the transport surface (2A) of the conveyor with the conveyor (2) forming the transport path (3) through which the object to be inspected (W) passes in the horizontal direction sandwiched. As described above, the X-ray generator and the X-ray detector are arranged.
The X-ray inspection apparatus (1) is an X-ray inspection apparatus (1) in which the object to be inspected is a container (W1) filled with a content (W2) containing a liquid.
A predetermined size including an empty packaging region (W3) in the container between the upper surface of the object to be inspected and the liquid level of the contents in the X-ray image based on the X-ray detected by the X-ray detector. Inspection target area extraction unit (43A) that extracts the inspection target area of
It is characterized by including a determination unit (44) for determining whether or not the content of the object to be inspected is normal based on the density of pixels of the X-ray image integrated in the inspection target area. X-ray inspection equipment. The X-ray inspection apparatus according to claim 1, wherein the inspection target area extraction unit extracts the inspection target area based on a predetermined length from the upper surface of the object to be inspected. Claim 1 is characterized in that the inspection target area extraction unit has an outer shape extraction unit (43B) for extracting the outer shape of the object to be inspected, and extracts an inspection target area having a predetermined size in the outer shape. The X-ray inspection apparatus according to the above.

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