JP3618701B2 - X-ray foreign object detection device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, for example, X-ray foreign matter for detecting foreign matter in the inspection object from the amount of X-ray transmission when X-rays are irradiated to the inspection object of various varieties such as raw meat, fish, processed food, and medicine More particularly, the present invention relates to an X-ray foreign matter detection device that can accurately detect defective products of an inspection object.
[0002]
[Prior art]
The X-ray foreign object detection device irradiates X-rays on various types of inspection objects (raw meat, fish, processed foods, medicines, etc.) that are sequentially transported on the transport line, and the amount of transmitted X-rays. This is a device that detects whether or not a foreign object such as metal, glass, stone, or bone is mixed in the inspection object.
[0003]
FIG. 6 is a perspective view showing a conventional X-ray foreign object detection apparatus of this type. As shown in the drawing, an X-ray generator 51 and an X-ray detector 52 are arranged opposite to each other at a position along the conveyor 50 where the inspection object W is being conveyed. The X-ray generator 51 emits X-rays to the object W being transported, and the X-ray detector 52 is an electric signal (X-ray transmission data) corresponding to the amount of X-rays transmitted through the object W to be inspected. Is output. A processing means (not shown) determines the presence or absence of foreign matter based on the amount of X-ray transmission.
[0004]
FIG. 7 is a view showing an X-ray transmission image of the object W to be inspected. As shown in FIG. 7A, X-ray detection is performed in a state where the inspection object W is accommodated in a container T such as a tray or a packaging film. This kind of X-ray foreign matter detection device detects the presence or absence of the inspection object W in the container T at the stage of pre-processing for determining the presence or absence of foreign matters in the inspection object W, and is a missing item (defective product). There is something that makes a distinction.
[0005]
This shortage determination process is determined by the processing means executing image processing. In the image processing unit, as shown in the figure, a missing item detection mask region M is set in advance at the coordinate axis position assuming the accommodation position of the inspection object W on the container T.
Then, the inspection object W that has been input and developed as shown in the figure overlaps the missing item detection mask area M, and the inspection object W exists on the position of the missing item detection mask area M. If it does not exist normally, it is judged as a missing item, and a signal indicating a missing item (defective item) is output to the outside.
[0006]
[Problems to be solved by the invention]
However, in the conventional shortage determination process, since the inspection object W is determined to be a shortage if the inspection object W does not completely overlap the portion of the shortage detection mask area M, depending on the case, Even if the inspection object W exists on the container T, it may be erroneously determined to be a missing item.
[0007]
This missing item detection mask region M is set by the operator of the apparatus with a predetermined range on a predetermined coordinate axis position. At this time, the operator has set the coordinate axis position and range in consideration of the movement (position shift) of the inspection object W on the container T.
Briefly, when the size of the inspection object W is ¼ or more of the size (area) of the container T, the inspection object W moves within the container T. However, there is always a position where the inspection object W exists. The coordinate axis position and range were set assuming this position.
[0008]
For this reason, as shown in FIG. 7B, when the inspection object W is inspected by the X-ray foreign matter detection apparatus 50, the position of the inspection object W is moved on the container T, and the missing item detection is performed. If a part of the mask area M is positioned outside the inspection object W, it is erroneously determined as a missing item.
Thus, in the past, experience and intuition were required for setting the missing part detection mask region M, and it was often erroneously determined as a missing part.
[0009]
In order to solve this problem, it is conceivable to enlarge the mask region M as shown in FIG.
However, if the mask region M is simply enlarged, the area (relative area) of the inspection object W with respect to the area of the mask region M decreases when the area of the inspection object W is small relative to the area of the container T.
In the above premise, if a normal product is used, a plurality of inspection objects W (W1, W2) are accommodated in the container T, a case where two inspection objects W are accommodated in the container T, and a single object. In the case where only one is accommodated (one missing item), there is no significant difference in relative area.
[0010]
As a result, as shown in FIG. 8B, there is a problem that even if one missing item is generated, this cannot be detected. In particular, the above-mentioned problem has occurred in products (for example, scotch eggs in bags) in which a plurality of objects to be inspected W have a small ratio to the container T and are accommodated.
[0011]
The present invention has been made in view of the above problems, and the relative area of the inspection object in the container is small, and even when a plurality of inspection objects are accommodated, the shortage of the inspection object is accurately detected. An object of the present invention is to provide an X-ray foreign object detection device that can improve the reliability of the device.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, X-rays are exposed to the inspection object (W) accommodated in the container (T), and the inspection object accompanies the X-ray exposure. In the X-ray foreign matter detection apparatus (1) for detecting the presence or absence of foreign matter in the inspection object from the amount of X-rays transmitted through
A plurality of threshold values different from each other with respect to the X-ray transmission amount of the inspection object inside the container.In advance according to the type of the object to be inspectedA threshold setting unit (17a) to be set;
An inspection object extraction unit (17b) for respectively obtaining areas of regions where the X-ray transmission amount on the inspection object is lower than each threshold set by the threshold setting unit;
The area of the inspection object obtained for each threshold by the inspection object extraction unit is compared with a predetermined reference area for each threshold, and the areas of the inspection objects for each threshold all exceed the corresponding reference area. A determination unit (17c) that determines that the object in the container is normal only when
It is provided with.
[0018]
According to the above configuration, the threshold setting unit 17a is configured for the X-ray transmission amount of the inspection object W.Different multiple valuesSet the threshold. The inspection object extraction unit 17bX-ray transmission amount is eachBelow thresholdArea areaTheRespectivelyAsk.Judgment part (shortage judgment part)17c isThe area of the inspection object W obtained for each threshold value is compared with a predetermined reference area for each threshold value, and only when the area of the inspection object W for each threshold value exceeds the corresponding reference area It is determined that the inspection object W in T is normal.
As a result, even when the area ratio of the inspection object W in the container T is small, a defect, a missing item, or the like of the inspection object W can be accurately detected, and an accurate defective product can be detected.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view showing an external appearance of the X-ray foreign object detection device.
The X-ray foreign matter detection apparatus 1 is provided in a part of the transport line and detects the presence or absence of foreign matter mixed in the inspection object W (including the surface) that is sequentially transported at a predetermined interval. In this X-ray foreign matter detection apparatus 1, a transport unit 3 and a foreign matter detection unit 4 are provided inside the apparatus main body 1a, and a display 7 is provided at the upper front of the apparatus main body 1a.
[0020]
The transport unit 3 transports, for example, test articles W of various varieties such as raw meat, fish, processed food, and medicine. In this embodiment, the test object W is placed in a container T such as a tray, a packaging film, or a box. It is transported in a housed state.
This conveyance part 3 is comprised with the belt conveyor arrange | positioned horizontally with respect to the apparatus main body 1a. The conveyance unit 3 conveys the inspection object W carried from the carry-in port 3a toward the carry-out port 3b (carrying direction X in the drawing) at a predetermined carrying speed set in advance by driving of the drive motor 6.
[0021]
The foreign matter detection unit 4 detects foreign matter in the middle of the transport path of the workpiece W to be transported, and an X-ray generator 8 provided at a predetermined height above the transport unit 3 and the transport unit 3 An X-ray detector 9 provided to face the X-ray generator 8 is provided.
[0022]
The X-ray generator 8 has a configuration in which a cylindrical X-ray tube 12 provided in a metal box 11 is immersed in an insulating oil (not shown), and an electron beam from the cathode of the X-ray tube 12 is an anode target. X-rays are generated by irradiation. The X-ray tube 12 is provided in a direction (Y direction) whose longitudinal direction is orthogonal to the conveyance direction X of the inspection object W. The X-rays generated by the X-ray tube 12 are exposed to the lower X-ray detector 9 in the form of a substantially triangular screen by a slit (not shown) along the longitudinal direction.
[0023]
The X-ray detector 9 detects X-rays that pass through the inspection object W when the X-rays are exposed to the inspection object W, and according to the detected transmission amount of the X-rays. An electrical signal is being output. The X-ray detector 9 is provided along the Y direction orthogonal to the transport direction X of the inspection object W transported on the transport unit 3. The X-ray detector 9 is an array line sensor including a plurality of photodiodes arranged in a line and a scintillator provided on the photodiode.
[0024]
In the X-ray detector 9 having such a configuration, when X-rays are exposed to the inspection object W from the X-ray generator 8, the X-rays transmitted through the inspection object W are received by the scintillator. And convert it to light. Further, the light converted by the scintillator is received by a photodiode disposed below the light. Each photodiode converts the received light into an electrical signal and outputs it. The X-ray detector 9 outputs an electrical signal having a level corresponding to the intensity of the received X-ray to the processing means 13.
[0025]
FIG. 2 is a block diagram showing an electrical configuration of the apparatus.
The processing means 13 is constituted by a CPU and the like and a memory and the like, and X-ray transmission data is input from the X-ray detector 9. The X-ray transmission data is A / D converted by an A / D converter (not shown) and then stored in the data memory 14.
In the data memory 14, for example, the above-mentioned 640 pieces of X-ray transmission data per line (Y direction) are at least the length (front end to rear end) in the transport direction X of the object W (container T) to be transported. A predetermined number of lines (for example, 480 lines) corresponding to (detection period up to) is stored. Based on this data, the processing means 13 inspects the contamination of the object W to be inspected.
[0026]
The conveyance unit 3 is provided with a position detector 10 such as a light projecting / receiving sensor that detects the container T including the inspection object W. The processing means 13 receives the output of the position detector 10 and uses the output at the time when the tip of the container T shields the light projecting / receiving position as a start trigger, and the shielding period is the length of the inspection object W ( The detection period of the container T is determined, and X-ray transmission data for each object W is taken into the data memory 14.
[0027]
The contents of the inspection process include whether or not foreign matter such as metal, glass, stone, or bone is mixed in the inspection object W based on an electrical signal corresponding to the transmission level of X-rays transmitted through the inspection object W. Make a decision. As a basic principle, when a state in which X-rays do not transmit due to foreign matter occurs, that is, when the value of the amount of X-ray transmission is low, it is determined that foreign matter is mixed and a selection signal or the like is output to the outside. Further, the image data obtained by directly developing the input data is output to the display unit 15 of the display unit 7 via the image processing unit 16.
[0028]
The processing means 13 is provided with a shortage detection unit 17 that determines the presence or absence (out of stock) of the inspected object W in the container T prior to the defective product discrimination processing related to the contamination. The missing part detection unit 17 is one function related to image processing in the image processing unit 16.
[0029]
The shortage detection unit 17 includes a threshold setting unit 17a and an inspection object extraction unit 17b., SizeIt has the cut part 17c.
In the threshold setting unit 17a, a threshold having a predetermined value is set for the X-ray transmission amount of the inspection object W. As the threshold value, one value or two values having different X-ray transmission amounts are set.
[0030]
FIG. 3 is a diagram for explaining the threshold value.
FIG. 3A shows the container T and the inspection object W. The container T is developed with the signal input timing of the start trigger whose tip is blocked by the position detector 10 during transport of the transport unit 3 as a reference position RF.
FIG. 3B is a diagram illustrating threshold values. In the illustrated example, two threshold values L1 and L2 having different values are set for the X-ray transmission amount of the inspection object W.
[0031]
The inspection object extraction unit 17b extracts the area of the X-ray transmission image of the inspection object W. The container T and the inspection object W have different X-ray transmission amounts, and the inspection object W generally has a lower X-ray transmission amount.
The inspection object extraction unit 17b obtains the number of pixels of the inspection object W exceeding the respective threshold values based on the threshold values L1 and L2. For the sake of convenience, it has been described as “exceeding the threshold value”, but in actuality, this means that the number of pixels of the object W on the side where the X-ray transmission amount is lower than the threshold value is counted.
[0032]
For example, in FIG. 3B, the pixels corresponding to the width H1 are counted in the portion where the X-ray transmission amount of the inspection object W exceeds the threshold L1, and the pixels corresponding to the width H2 are counted in the portion exceeding the threshold L2. Be counted. In the drawing, the width direction has been described for the sake of convenience, but at the same time, portions exceeding the threshold values L1 and L2 also occur in the length direction, and the number of pixels exceeding the threshold values L1 and L2 is counted.
[0033]
Due to differences in the shape of the inspection object W and X-ray transmittance, the area of the inspection object W obtained using the threshold values L1 and L2 is different, and this is used to detect a missing item or crushing of the inspection object W. it can.
[0034]
In the example shown in FIG. 3C, the inspection object W can obtain pixels having a predetermined area with a width H1 exceeding the threshold value L1 on the side where the amount of X-ray transmission is high. However, this inspection object W shows a case where the X-ray transmission amount does not exceed the low threshold L2 side and the area on the threshold L2 side cannot be obtained and becomes zero.
When the threshold values L1 and L2 are set so as to exceed both according to the type of the inspection object W, if the inspection object W does not exceed one threshold value L2 side, the X-ray transmission state of the inspection object W is abnormal and the product is defective. It can be used for judgment.
[0035]
In the example shown in FIG. 3D, the inspection object W exceeds both the thresholds L1 and L2, and the X-ray transmission state becomes normal without any problem. In the figure, the width H1 is obtained by the threshold value L1. The width H2 is obtained by the threshold value L2. When these widths H1 and H2 are small, the size of the area obtained by the length can be determined. For example, when the object W is crushed and its shape is deformed, the widths H1 and H2 are reduced as illustrated. When these widths H1 and H2 are reduced, the crushing of the inspection object W can be detected, and it can be used for determining a product defect.
[0036]
Although not shown in detail, the X-ray transmission image after image expansion displayed on the display unit 15 or the like has a different display density according to the X-ray transmission amount.
[0037]
SizeReference areas R1 and R2 that are used as references for threshold values L1 and L2, respectively, are set in advance in the cut portion 17c corresponding to the type of the inspection object W.
Compared to the reference areas R1 and R2, the areas obtained when X-ray inspection is performed for each inspection object W one by one, and if either of them does not exceed the reference area, the inspection object W is missing. Judged as a product (product abnormality).
[0038]
Next, an X-ray foreign object detection operation with the above configuration will be described.
In the X-ray foreign matter detection apparatus 1 configured as described above, when the inspection object W is carried in from the carry-in port 3a of the conveyance unit 3, the X-ray generator 8 sends the inspection object W to the inspection object W during the conveyance process. Is exposed. X-rays that pass through the inspection object W with the X-ray exposure are detected by the X-ray detector 9.
[0039]
Then, the processing means 13 determines whether or not foreign matter is mixed in the inspection object W based on the electric signal indicating the X-ray transmission amount detected by the X-ray detector 9, and the non-defective product is determined from the determination result. Alternatively, a sorting signal indicating a defective product is output to the outside. Specifically, when the detected X-ray transmission amount of the inspection object W exceeds a threshold set for detecting foreign matter, it is determined that foreign matter is mixed. This threshold value has a lower X-ray transmission amount than the shortage detection threshold values L1 and L2, and the foreign matter such as metal when the X-ray transmission amount is lower than the threshold value for detecting the foreign matter. Is determined to be mixed.
Then, the inspection object W that has been subjected to the inspection is sorted into a non-defective product and a defective product according to a sorting signal output from the processing means 13.
[0040]
Further, the image processing unit 16 of the processing unit 13 displays and outputs image data indicating the X-ray transmission amount output from the X-ray detector 9 on the display unit 15. The state of the outer shape of the inspection object W including the container T viewed from the plane and the X-ray transmission state in the inspection object W can be confirmed, and the display density of the foreign matter portion is different from others (darker). , Or other colors) and the position where the foreign substance is mixed can be grasped.
Also, the pass / fail judgment results of “OK” and “NG”, and the inspection results of the total number of inspections, the number of non-defective products, and the total number of NG are displayed.
[0041]
Here, the processing means 13 compares the data stored in the data memory 14 with a reference value, and determines that the data is NG when the X-ray transmission amount is lower than the reference value (when X-rays do not pass through due to foreign matter). When the amount of X-ray transmission is higher than the reference value, it is determined that it is OK, and “NG” or “OK” is displayed.
[0042]
Next, the defective product detection operation of the inspection object W in the above configuration will be described. FIG. 4 is a flowchart showing this defective product detection process.
Prior to the foreign matter detection operation, the shortage detection unit 17 detects the presence / absence of the inspection object W in the container T (such as a defective shape such as a shortage, chipping or crushing).
The image processing unit 16 develops the X-ray transmission data output from the X-ray detection unit 9 as an X-ray transmission image in a state including the container T and the inspection object.
[0043]
In the shortage detection unit 17, first, an appropriate threshold value and a reference area R corresponding to the threshold value are set according to the type of the inspection object W (S1).
In the above configuration example, threshold values L1 and L2 having two different values are set. As described above, the threshold values L1 and L2 are set to a relatively high X-ray transmission amount that is not determined as a foreign object, unlike the threshold values for detecting a foreign object.
As for the reference area R, an area R1 obtained when the inspection target W serving as a normal reference is cut at the threshold value L1 and an area R2 obtained when the inspection object W is cut at the threshold value L2 are set.
[0044]
Next, the image data of the inspection object W conveyed on the conveyance unit 3 which is an inspection object is captured (S2). At this time, the reference position RF of the container T is detected based on the captured X-ray transmission image. This reference position RF is a time when the position detector 10 detects the leading position of the container T, and corresponds to the position of the leading edge (one end) of the container T in the X-ray transmission image. When the reference position RF of the container T is detected, image data corresponding to the length in the transport direction of the container T set in advance with the reference position RF is taken in.
[0045]
Next, the inspection object extraction unit 17b calculates the area of the inspection object W with respect to the captured image data.
The inspection object extraction unit 17b obtains the area M1 of the image data that exceeds the threshold value L1 set by the threshold setting unit 17a (the X-ray transmission amount is low) by counting the number of pixels (S3). Similarly, the area M2 exceeding the threshold L2 is obtained by counting the number of pixels (S4).
[0046]
SizeThe cut portion 17c detects the state of the inspection object W in the container T by comparing the areas M1 and M2 of the inspection object W with the reference areas R1 and R2, and determines whether the inspection object W is normal or defective (missing or missing, A shape defect such as crushing).
[0047]
First, the area M1 of the inspection object W obtained based on the threshold value L1 is compared with the reference area R1 (S5). The comparison can be easily performed by comparing the number of pixels. As a result of the comparison, if the area M1 of the inspection object W is larger than the reference area R1 (S5—Yes), then the determination at the threshold L2 is performed in S6, but the area M1 of the inspection object W is smaller than the reference area R1. If this is the case (S5-No), error processing for defective products is performed (S8). In the error process, it is determined that the inspection object W is a missing item that does not contain a specified number. For example, a display output indicating a shortage state is performed on the display unit 15, or a signal for discharging the corresponding container T to the subsequent sorter is output to the outside.
[0048]
Next, the area M2 of the inspection object W obtained based on the threshold value L2 is compared with the reference area R2 (S6). As a result of the comparison, if the area M2 of the inspection object W is larger than the reference area R2 (S6-Yes), it is determined that the inspection object W is normal (S7).
On the other hand, if the area M2 of the inspection object W is smaller than the reference area R2 (S6-No), error processing of defective products is performed (S8).
As described above, as a result of the comparison between the area M1 based on the threshold value L1 and the reference area R1 and the comparison between the area M2 based on the threshold value L2 and the reference area R2, one of the areas M1 and M2 is greater than the reference areas R1 and R2. If it is small, it is judged as defective. The normal judgment is only when both the areas M1 and M2 are larger than the reference areas R1 and R2.
[0049]
FIG. 5 is a diagram illustrating various states of the inspection object W in the container T.
(A), (b) is a figure which shows a normal state, (c)-(g) is a figure which shows a defect (error state). It is assumed that the inspected object W is manufactured by containing different types of contents F having a low X-ray transmission amount, and the outer diameter is almost spherical.
[0050]
FIG. 5A shows a state in which two inspection objects W (W1, W2) are individually detected in the container T. In this case, the X-ray transmission amount is detected at a different position for each of the inspection objects W1 and W2.
Further, the X-ray transmission amounts of the inspection objects W1 and W2 exceed both the threshold values L1 and L2, and the areas M1 and M2 obtained based on the threshold values L1 and L2 are larger than the reference areas R1 and R2. Therefore, it is judged to be normal without missing items. At the same time, in this case, the amount of X-ray transmission can be detected as two because the two inspection objects W1 and W2 are detected at different positions.
[0051]
FIG. 5B shows a state in which two inspection objects W (W1, W2) are detected in contact with each other within the container T. In this case, the X-ray transmission amount is detected in a single form in which the inspection objects W1 and W2 are connected.
However, the X-ray transmission amounts of the inspection objects W1 and W2 both exceed the threshold values L1 and L2. The total of two areas M1 of the inspected objects W1 and W2 is larger than the total value of the two reference areas R1. Further, the sum of the areas M2 of the two inspection objects W1 and W2 is larger than the total value of the two reference areas R2. Since both are satisfied, it is judged to be normal with no shortage. That is, when only the X-ray transmission amount is seen, the waveforms of two independent inspection objects W1 and W2 cannot be obtained, but are normal because the total area is detected as two as described above. It is judged.
[0052]
FIG. 5C shows a defective state in which the inspection objects W1 and W2 are independent in the container T, but one inspection object W2 is small.
In this case, the X-ray transmission amount is detected at a different position for each of the inspection objects W1 and W2.
The X-ray transmission amount of the inspection object W1 exceeds the threshold L1, and the area M1 is larger than the reference area R1.
However, since the inspection object W2 has a small diameter, the area M1 of the threshold value L1 is smaller than the reference area R1. Further, the threshold M2 does not exceed the threshold L2 in terms of the amount of X-ray transmission, and the area M2 is smaller than the reference area R2. As a result, it is determined as a failure (error).
Note that it is possible to detect that the number is two because these two inspection objects W1 and W2 are detected at different positions in terms of the X-ray transmission amount.
[0053]
FIG. 5 (d) shows a case where one inspection object W2 is small and defective. In the illustrated example, the width H2 is small. It is assumed that two inspection objects W (W1, W2) are detected in contact with each other in the container T. In this case, the X-ray transmission amount is detected in a single form in which the inspection objects W1 and W2 are connected.
The X-ray transmission amounts of the inspection objects W1 and W2 both exceed the threshold value L1, but since the area M2 of the inspection object W2 is small, the total of the areas M1 corresponding to the two inspection objects W1 and W2 Is smaller than the total value of the two reference areas R1.
Further, since one inspection object W2 is small, the threshold value L2 is not exceeded, and the total of the two areas M2 of the inspection objects W1 and W2 is smaller than the total value of the two reference areas R2. As a result, it is determined as a failure (error).
[0054]
FIG. 5E shows a state in which the inspection objects W1 and W2 are independent in the container T, but one inspection object W2 is in a defective state in which only the contents F are stored.
In this case, the X-ray transmission amount is detected at a different position for each of the inspection objects W1 and W2.
The X-ray transmission amount of the inspection object W1 exceeds both the threshold values L1 and L2, and the area M1 is larger than the reference area R1.
However, the inspection object W2 has only the contents F and has a small diameter. At this time, if the contents F are relatively difficult to transmit X-rays, even if the threshold value L2 exceeds the threshold value L2 in terms of the X-ray transmission amount, the area M2 is smaller than the reference area R2, and thus is determined to be defective (error). Is done.
As described above, it is possible to detect a defect of the inspection object W2 by comparing not only the threshold value L2 but also the area M2 exceeding the threshold value L2.
Note that it is possible to detect that the number is two because these two inspection objects W1 and W2 are detected at different positions in terms of the X-ray transmission amount.
[0055]
FIG. 5F shows a case where one inspection object W2 is small and defective. In the illustrated example, the length direction orthogonal to the width is small.
The X-ray transmission amount is detected at a different position for each of the inspection objects W1 and W2.
The X-ray transmission amounts of the inspection objects W1 and W2 both exceed the threshold value L1, but the length direction of the inspection object W2 is small, and therefore the area M2 is small even if the width H2 is a predetermined width. The total of the areas M1 for the two inspection objects W1 and W2 is smaller than the total value of the reference areas R1 for the two inspection objects.
Further, since one inspection object W2 is small, the threshold value L2 is not exceeded, and the total of the two areas M2 of the inspection objects W1 and W2 is smaller than the total value of the two reference areas R2. As a result, it is determined as a failure (error).
Note that it is possible to detect that the number is two because these two inspection objects W1 and W2 are detected at different positions in terms of the X-ray transmission amount.
[0056]
FIG. 5G shows a case where both the inspected objects W1 and W2 have a prescribed outer diameter, but one of the inspected objects W2 does not contain the content F.
The X-ray transmission amount is detected at a different position for each of the inspection objects W1 and W2.
The X-ray transmission amounts of the inspection objects W1 and W2 both exceed the threshold L1, and the areas of the two areas M1 and M2 are larger than the sum of the two reference areas R1 and R2.
However, since the inspection object W2 does not include the contents F, the threshold L2 is not exceeded and the area M2 is zero. Therefore, the total area M2 of the two inspection objects W1 and W2 is two. It becomes smaller than the total value of the reference area R2 of the minute.
As a result, it is determined as a failure (error).
Note that it is possible to detect that the number is two because these two inspection objects W1 and W2 are detected at different positions in terms of the X-ray transmission amount.
[0057]
Further, in the example shown in FIGS. 5C, 5D, 5F, and 5G, the content F is compared when the defect does not include the other content F on the inspection object W2 side. When the target X-rays are difficult to transmit, it is possible to detect the loss of the contents F in the inspection object W by setting the threshold value L2.
[0058]
Also, SizeThe cut portion 17c can also determine the shape defect of the inspection object based on the shapes of the inspection objects W1 and W2 obtained by the inspection object extraction unit 17b. That is, the shape of the inspection object W can be identified by the width H and the length obtained by the respective threshold values L1 and L2, both in the case where the width and the length are smaller than the predetermined allowable range and in the case where it is larger. It can be determined that the product has a defective shape.
[0059]
In the above-described embodiment, the reference position RF is obtained by detecting the tip position in the transport direction of the inspection object W including the container T with the position detector 10. However, the present invention is not limited to this, and the reference position RF may be set by detecting the tip position of the container T based on the X-ray transmission amount during image processing in the image processing unit 16. In this case, the position detector 10 is unnecessary.
[0060]
The varieties of the test object W and the container T will be described in detail. A product in which a plurality of scotch eggs (two eggs in a spherical hamburger) are stored in a film-shaped container T is provided. is there.
In this product, the size of the test object W is smaller than the size of the container T, the ratio of the size of the test object W to the container T is small, and the test object W is contained in the container T. Easy to move. According to the above-described embodiment, the configuration using the area based on the threshold can accurately detect defects (defects, missing items, shape defects, etc.) of the inspection object W.
[0061]
【The invention's effect】
According to the present invention, it is possible to easily detect the presence or absence of an object to be inspected inside the container by X-ray detection. Even if the size of the inspected object is small relative to the size of the container, the quality of the inspected object can be judged by the area judgment using the threshold, the number of inspected objects, defects, missing items, Even if there is a contact, it is possible to prevent misjudgment and accurately judge whether it is good or bad, and improve the reliability of defective product detection.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an external appearance of an X-ray foreign object detection device according to the present invention.
FIG. 2 is a block diagram showing an electrical configuration of an X-ray foreign object detection device according to the present invention.
FIG. 3 is a diagram for explaining setting of a threshold and an area.
FIG. 4 is a flowchart showing defective product detection processing.
FIG. 5 is a view for explaining a pass / fail state of an object to be inspected in a container.
FIG. 6 is a perspective view showing a configuration of an X-ray foreign object detection device.
FIG. 7 is a diagram (part 1) for explaining a conventional defective product detection process;
FIG. 8 is a diagram for explaining a conventional defective product detection process (part 2);
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... X-ray foreign material detection apparatus, 3 ... Conveyance part, 8 ... X-ray generator, 9 ... X-ray detection part, 13 ... Processing means, 16 ... Image processing part, 17 ... Missing part detection part, 17a ... Threshold setting part , 17b ... inspection object extraction unit, 17c ... determination unit, T ... container, W (W1, W2) ... inspection object.

Claims (1)

The object to be inspected (W) accommodated in the container (T) is exposed to X-rays, and the object to be inspected is determined from the amount of X-ray transmitted through the object to be inspected as the X-rays are exposed. In the X-ray foreign matter detection device (1) for detecting the presence or absence of foreign matter in an object,
A threshold setting unit (17a) for setting a plurality of different threshold values for the amount of X-ray transmission of the inspection object inside the container in advance according to the type of the inspection object ;
An inspection object extraction unit (17b) for respectively obtaining areas of regions where the X-ray transmission amount on the inspection object is lower than each threshold set by the threshold setting unit;
The area of the inspection object obtained for each threshold by the inspection object extraction unit is compared with a predetermined reference area for each threshold, and the areas of the inspection objects for each threshold all exceed the corresponding reference area. A determination unit (17c) that determines that the object in the container is normal only when
An X-ray foreign matter detection apparatus comprising:

Images