JP6933496B2 - 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. An empty-packed area extraction unit for extracting an empty-packed area in the container is provided, and the content of the object to be inspected is inspected based on the area of the empty-packed area.

With this configuration, the container shape of the object to be inspected is the same, and the liquid that is the content is located at the lower part of the container. Since the content is inspected based on the size, the inspection accuracy of the content to be inspected can be improved.

In the X-ray inspection apparatus according to the present invention, the blank region extraction unit has an outer shape extraction unit that extracts the outer shape of the object to be inspected, and compares the concentration in the outer shape with a predetermined concentration threshold to obtain the above. It is characterized by extracting an empty package area.

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.

In the X-ray inspection apparatus according to the present invention, the blank region extraction unit compares the concentration in the region from the upper surface of the object to be inspected to a predetermined length downward with a predetermined concentration threshold value, and performs the blank region extraction unit. It is characterized by extracting a region.

With this configuration, it is possible to inspect the content in the minimum height area that takes into account fluctuations in the height direction of the contents of normal products, so detection accuracy due to the spread of X-rays in the height direction. Can be minimized.

The X-ray inspection apparatus according to the present invention is characterized by including a threshold value setting unit for setting the density threshold value on a display screen.

With this configuration, a desired concentration threshold can be easily set.

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 which shows the original image of the X-ray image in the X-ray inspection apparatus which concerns on one Embodiment of this invention. It is a figure which shows the black-and-white inverted image which performed the black-and-white inversion processing of the original image in the X-ray inspection apparatus which concerns on one Embodiment of this invention. It is a figure which shows the binarized image which binarized the black-and-white inverted image in the X-ray inspection apparatus which concerns on one Embodiment of this invention. It is a figure which shows the blank area image which deleted the unnecessary part from the binarized image, and made only the blank area in the X-ray inspection apparatus which concerns on one Embodiment of this 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 the blank area extraction unit 43A. The blank area extraction unit 43A extracts the blank area 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.

The blank area extraction unit 43A has an external shape extraction unit 43B that extracts the outer shape of the object W to be inspected, and extracts the blank area W3 by comparing the concentration in the outer shape with a predetermined concentration threshold value. Then, the blank region extraction unit 43A extracts the blank region W3 by comparing the concentration in the region from the upper surface to the lower side of the object W to be inspected with a predetermined concentration threshold value.

The display unit 5 and the setting operation unit 45 function as a threshold value setting unit for setting the density threshold value on the display screen.

In the present embodiment, the determination unit 44 inspects the content of the object W to be inspected based on the size of the blank area W3 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, an X-ray image as the original image shown in FIG. 4 is captured. The original image of FIG. 4 shows a non-defective product having a positive amount of contents and an NG product having a small amount of contents side by side for explanation.

This original image includes a region due to the 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 original 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 a region of the object W to be inspected from the X-ray image based on a predetermined density threshold value (step S2). In step S2, the X-ray inspection apparatus 1 removes the region due to the reflection of the conveyor member 21 from the X-ray image to extract only the region of the object W to be inspected, and the region of the object W to be inspected. On the other hand, density inversion processing (black and white inversion processing) is performed.

Specifically, as shown in FIG. 5, a black-and-white inverted image in which the shading of the original image is inverted is created. This black-and-white inverted image is created for the purpose of facilitating the extraction of the blank area W3 by making the density difference between the background and the blank area W3 larger than the density difference between the background and the content W2. ..

Next, the X-ray inspection apparatus 1 binarizes the blank region W3 in the black-and-white inverted image of FIG. Here, a binarized image obtained by binarizing a black-and-white inverted image is created based on a predetermined reference value.

As a result, as shown in FIG. 6, the blank area W3 to be inspected is extracted including the portion of the container W1. In FIG. 6, the region of the content W2 is binarized to white and is not extracted.

Next, the X-ray inspection apparatus 1 extracts the blank region W3 from the object W to be inspected (step S3). The extraction of the blank region W3 is performed by an image process of an opening process (contracting and expanding by the same number of times) as a thin line removing process.

Specifically, the X-ray inspection apparatus 1 performs a thin line removal process on the binarized image of FIG. 6 by image processing to erase unnecessary parts such as a part on the X-ray image in the container W1. That is, in order to identify only the blank area W3 from the binarized image of the blank area W3 including the part of the container W1 by binarization, other than the reflection area such as the part of the container W1 and the printed part of the container W1. Is erased from the X-ray image, and finally the image of FIG. 7 is obtained.

Next, the X-ray inspection apparatus 1 calculates the area of the blank area W3 (step S4), and determines the amount of the content W2 based on this area (step S5).

The method of obtaining the blank area W3 of FIG. 7 obtained in this way is an example, and the original image may be binarized by masking the background without using the black-and-white inverted image as described above. good. Further, since the concentration of the blank area W3 is between the density of the background and the concentration of the contents, the blank area is binarized so as to extract the concentration in a predetermined range, and then the blank area is subjected to a thin line removal treatment or the like. W3 may be obtained.

As described above, in the X-ray inspection apparatus 1 of the present embodiment, the blank area extraction unit 43A is the upper surface and the contents of the object W to be inspected in the X-ray image based on the X-ray detected by the X-ray detector 10. The blank region W3 between the liquid level of W2 and the liquid level is extracted. Then, the content of the object to be inspected W is inspected based on the size of the blank area W3.

With this configuration, the shape of the container W1 of the object W to be inspected is the same, and the liquid which is the content W2 is located in the lower part of the container W1, which is smaller than the height of the content W2 formed in the upper part of the container W1. Since the content is inspected based on the size of the empty package area W3 which is the height, the inspection accuracy can be improved.

Further, in the X-ray inspection apparatus 1 of the present embodiment, the blank area extraction unit 43A has an outer shape extraction unit 43B that extracts the outer shape of the object W to be inspected, and sets the concentration in the outer shape and a predetermined density threshold value. The blank region W3 is extracted by comparison.

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

Further, in the X-ray inspection apparatus 1 of the present embodiment, the blank region extraction unit 43A compares the concentration in the region from the upper surface to the lower side of the object W to be inspected with a predetermined concentration threshold value. The blank region W3 is extracted.

With this configuration, it is possible to inspect the content in the minimum height region that takes into account the fluctuation of the contents W2 of the normal product in the height direction, so that the detection accuracy due to the spread of X-rays in the height direction is possible. Can be minimized.

Further, the X-ray inspection apparatus 1 of the present embodiment includes a display unit 5 and a setting operation unit 45 as threshold value setting units for setting the density threshold value on the display screen.

With this configuration, a desired concentration threshold can be easily set.

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 43 Image processing unit 43A Blank area extraction unit 43B External shape extraction unit 45 Setting operation unit (threshold setting unit)
W Inspected object W1 Container W2 Contents W3 Blank area

Claims (4)

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.
An empty-packed area (W3) for extracting an empty- packed area (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. Equipped with an extraction unit (43A)
An X-ray inspection apparatus for inspecting the content of the object to be inspected based on the area of the blank area. The blank area extraction unit has an external shape extraction unit (43B) for extracting the outer shape of the object to be inspected, and extracts the blank area by comparing the concentration in the outer shape with a predetermined concentration threshold value. The X-ray inspection apparatus according to claim 1. The claim characterized in that the blank region extraction unit extracts the blank region by comparing the concentration in the region from the upper surface to the lower side of the object to be inspected to a predetermined concentration threshold with a predetermined concentration threshold value. The X-ray inspection apparatus according to claim 1 or 2. The X-ray inspection apparatus according to claim 2 or 3 , further comprising a threshold value setting unit that sets the density threshold value on the display screen.

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