JP5289780B2 - X-ray foreign object detection device - Google Patents

Description

  The present invention relates to an X-ray foreign matter detection device that detects the presence or absence of foreign matter in a test object such as raw meat, fish, processed food, medicine, etc. It is about the technology to adjust.

  For example, in order to detect the presence or absence of foreign matter (metal, glass, shell, bone, etc.) in an object to be inspected such as food, an X-ray foreign matter detection device has been conventionally used. In this type of conventional X-ray foreign object detection device, the object to be inspected is irradiated with X-rays, and it is detected from the amount of transmitted X-rays whether foreign objects are mixed in the object to be inspected. The presence or absence of foreign matter is then checked. In addition, in this type of X-ray foreign matter detection apparatus, when starting the inspection for the presence of foreign matter, a test piece in which a plurality of types of foreign matter are embedded is transported over the inspection subject for each inspection subject, and the detectable foreign matter Confirmation and adjustment of (type and size). When the type and size of the detectable foreign matter are determined, the determined detectable foreign matter (foreign matter detection sensitivity) is used as a management standard for the presence / absence inspection of the foreign matter (see, for example, Patent Document 1).

  Furthermore, in order to maintain the foreign matter detection sensitivity and improve the reliability of the inspection, generally, an operation check is performed as to whether there is any defect or abnormality as necessary. For example, when using after a long period of non-use, or in special cases where high accuracy is required, use a foreign object test piece that can be detected before starting use to check whether the detection function is normal. ing.

Further, in this type of X-ray foreign matter detection apparatus, in order to detect foreign matter from an inspection object with high sensitivity, the amount of X-ray transmission is digitized and image processing is performed to emphasize the foreign matter using an image processing filter. Thus, foreign matter is detected. There are various filters for this image processing filter, but the atomic number, density, and thickness of each object to be inspected or foreign matter are different. Depending on the X-ray image processing filter, the influence of the object to be inspected is not reduced well, In some cases, a foreign object signal is extracted from an inspection object that is not mixed. Therefore, as a method for selecting an optimum X-ray image processing filter in order to detect foreign matter with high sensitivity, a plurality of types of X-rays for emphasizing foreign matter with respect to good X-ray intensity data in which no foreign matter is mixed. An X-ray image processing filter that performs image processing using an image processing filter and generates an X-ray image having the minimum maximum pixel value among the X-ray image data generated for each X-ray image processing filter is There is an X-ray image processing filter automatic setting method that is extracted and set as an X-ray image processing filter (see, for example, Patent Document 2).
International Publication Number WO2006 / 001465 A1 JP 2004-28891 A

  However, even if an optimum X image processing filter is set and foreign matter can be detected from the inspection object with high sensitivity, it has not been understood to what extent foreign matter can actually be detected. In order to check how large foreign objects can be detected, it is necessary to transport multiple types of test pieces together with the inspection object for each inspection object, and it is appropriate as a management standard for each inspection object. Since the types of test pieces are different and the types of test pieces to be used tend to increase, it is complicated for the administrator. It is also necessary to secure a place for storing the test pieces in the best condition. In addition, it takes time to grasp a foreign object that can be detected using the test piece, and there is a problem that the operation is complicated for the operator.

  Therefore, the present invention provides an X-ray foreign object detection apparatus that can solve the conventional problems as described above and can estimate the size of a detectable foreign object while eliminating the need for a test piece for confirming the foreign substance detection sensitivity. The purpose is to do.

In order to achieve the above object, the X-ray foreign object detection device according to claim 1 of the present invention is detected by transmitting through the inspection object when the inspection object W being conveyed is irradiated with X-rays. An image processing unit 8 that performs image processing for extracting a foreign substance on an X-ray image based on an X-ray transmission amount is provided, and the foreign object is present in the inspection object based on the image processing result of the image processing unit. In the X-ray foreign object detection device 1 for determining whether or not it is included,
A foreign matter sample image generating unit 6 for generating X-ray images of a plurality of foreign matter samples having different sizes detected based on predetermined X-ray output conditions as foreign matter sample images;
An image composition unit 7 for outputting a composite image in which the foreign material sample image generated by the foreign material sample image generation unit is superimposed on the X-ray image at a plurality of positions;
As a result of image processing of a plurality of foreign substance sample composite images output from the image composition unit, detection is performed based on a foreign substance extraction rate extracted as a foreign substance among the plurality of positions where the foreign substance sample images are superimposed. Foreign matter detection sensitivity estimation means 8a for estimating the size of possible foreign matter ,
And a display unit 10 for displaying the size of the detectable foreign matter estimated by the foreign matter detection sensitivity estimation means and the foreign matter sample composite image .

The X-ray foreign matter detection device according to claim 2 is the X-ray foreign matter detection device according to claim 1,
The foreign object sample image generation unit 6 includes a storage unit 6a for storing foreign object sample images of a plurality of types of foreign objects detected based on the predetermined X-ray output condition,
The foreign object detection sensitivity estimation means 8a estimates the size of a foreign object that can be detected for each type of foreign object.

The X-ray foreign matter detection device according to claim 3 is the X-ray foreign matter detection device according to claim 2,
The foreign object detection sensitivity estimation means 8a applies a filter process prepared for each type of foreign object to the composite image, and selects a filter process that can extract the smallest foreign object as an optimum filter.

The X-ray foreign matter detection device according to claim 4 is the X-ray foreign matter detection device according to any one of claims 1 to 3,
Processing means 7a for converting the density of the foreign material sample image generated by the foreign material sample image generation unit 6 in accordance with the X-ray output condition when the X-ray image is acquired;
The image composition unit 7 outputs a composite image obtained by superimposing the foreign substance sample image converted by the processing means on the X-ray image at a desired position.

The X-ray foreign matter detection device according to claim 5 is the X-ray foreign matter detection device according to any one of claims 1 to 4,
An X-ray image obtained when a desired foreign object is conveyed under a predetermined X-ray output condition is registered and stored in the storage unit 6a as a foreign object sample image related to the foreign object.

The X-ray foreign matter detection device according to claim 6 is the X-ray foreign matter detection device according to any one of claims 1 to 5,
A display unit 10 for displaying a transmission image of the inspection object W is provided, and a synthesis position of the foreign object sample image is designated on the transmission image displayed on the display unit.

The X-ray foreign matter detection device according to claim 7 is the X-ray foreign matter detection device according to any one of claims 1 to 5,
The composition position of the foreign object sample image with respect to the transmission image is determined based on the density distribution of the transmission image of the inspection object W.

  According to the X-ray foreign object detection device of the present invention, X-ray images of a plurality of foreign object samples having different sizes detected based on predetermined X-ray output conditions are stored as foreign object sample images, and this foreign object sample image is stored. Can be estimated to the size of a detectable foreign object without using an actual foreign object sample.

  By storing foreign object sample images corresponding to multiple types of foreign objects detected based on predetermined X-ray output conditions, that is, multiple foreign object samples of different materials and shapes, depending on the type (type) of inspection object The range of the size of the foreign object that can be detected as a foreign object from the test object can be estimated for each material and shape of the foreign object.

  A plurality of types of foreign object sample images are stored, these foreign object sample images are respectively combined with the inspection object image to determine whether the foreign object can be extracted, and an optimum filter is determined. A filter that can detect foreign matter with high sensitivity can be set without actually using a plurality of foreign matter samples.

  Based on the X-ray output conditions of the X-ray generator that are optimally set according to the characteristics of the inspection object and the conveyance speed, the density of the transmission image of the inspection object is processed by converting the density of the foreign object sample image. Even when the value changes, it is possible to synthesize the foreign object sample image with an appropriate density, and to more accurately estimate whether the foreign object sample image can be extracted.

  By storing an arbitrary X-ray image as a foreign object sample image, an X-ray image of the foreign object sample can be combined with an X-ray image of the object to be inspected and extracted as a foreign object. Can be estimated.

  Since it is possible to specify the composite position of the foreign object sample image on the displayed transmission image, a predetermined foreign substance sample determined by the user can be obtained in the same manner as when the foreign object sample is actually attached to each position of the inspection object. A foreign object sample image can be synthesized at the position.

  By setting the composite position of the foreign object sample image from the density distribution of the transmission image of the inspection object, the calculation amount and time can be reduced by narrowing down the position where the foreign object sample image is combined according to the characteristics of the inspection object. It can be estimated appropriately whether a foreign material can be extracted.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a block diagram of a first embodiment of an X-ray foreign object detection device according to the present invention, and FIG. 2 is a composition process of an X-ray image of a test object and a foreign object sample image in the X-ray foreign object detection device according to the present invention. 3 (a) and 3 (b) are diagrams showing examples of the thickness and lightness level of the inspection object in the X-ray foreign object detection device according to the present invention, and FIG. 4 is an X-ray foreign object detection device according to the present invention. FIG. 5 to FIG. 9 are diagrams showing various examples of composite images of foreign object sample images subjected to processing (size conversion and density conversion) and inspection object images, and FIG. FIG. 11 is a flowchart showing an operation of the X-ray foreign object detection apparatus according to the present invention when the foreign object sample inspection mode is optimized, and FIG. 11 is an operation flowchart of the X-ray foreign object detection apparatus according to the present invention when the foreign object sample inspection mode is fixed. FIG. e) is an explanatory diagram relating to the process of determining the composite position from the density distribution in the X-ray foreign object detection apparatus according to the present invention, FIG. 13 is a diagram showing a display example of the X-ray foreign object detection apparatus according to the present invention, and FIG. FIG. 15 is an explanatory diagram regarding the X-ray absorption when the foreign object sample image is manually set, and when the foreign object is combined only with the foreign object. is there.

  The X-ray foreign object detection apparatus according to the present invention is incorporated as a part of a production line in which inspected objects such as raw meat, fish, processed food, and medicine are sequentially transported at a predetermined interval. This is to detect whether or not foreign matter is mixed.

  The X-ray foreign material detection apparatus of this example creates a composite image in which a foreign material sample image of various foreign materials is generated, and the generated foreign material sample image is superimposed on a desired position of an X-ray absorption image of an inspection object. A function for performing foreign object detection processing on a composite image, identifying and displaying a detectable foreign object, a function for checking the operation of an optimal foreign object detection process based on the result of the foreign object detection process using the composite image, and an X-ray absorption image of the inspection object For example, a function for determining a composite position of a foreign material sample image to be superimposed on the image, a function for storing a foreign material sample image by an arbitrary foreign material, and the like.

  And in order to implement | achieve each said function, as shown in FIG.1 and FIG.2, X-ray foreign material detection apparatus 1 (1A, 1B) is the conveyance part 2, the operation input part 3, the detection part 4, and the image memory | storage part 5. , A foreign matter sample image generation unit 6, an image synthesis unit 7, an image processing unit 8, a determination unit 9, and a display unit 10.

  First, the configuration of the first embodiment of the X-ray foreign matter detection apparatus 1 according to the present invention will be described with reference to FIG.

  In FIG. 1, the transport unit 2 sequentially inspects the inspected objects W of the varieties set and input in advance from the operation input unit 3 from various varieties such as raw meat, fish, processed foods, and medicines at predetermined intervals. Conveying. In the example of FIG. 1, the transport unit 2 is configured by a belt conveyor disposed horizontally with respect to the apparatus main body, and the direction of the arrow in FIG. 1 at a predetermined transport speed set in advance by driving a drive motor (not shown). The inspection object W carried in from the previous process (carry-in entrance) is carried out to the subsequent process (carry-out exit).

  In addition, the conveyance part 2 is not limited to the belt conveyor shown in FIG. 1, For example, as disclosed by patent document 1, for example, shellfish such as clams, fish surimi, retort food ingredients, ingredients It is good also as a structure which carries out the flow conveyance of the to-be-inspected objects W, such as soup containing a material, sequentially in a pipe with a conveyance pump.

  The operation input unit 3 sets a product type for specifying the type of the inspection object W to be transported by the transport unit 2, sets the type and size of the foreign material sample image read from the foreign material sample image generation unit 6 described later, and a detection unit. 4 X-ray output conditions (X-ray tube voltage and tube current) setting, selection of various modes, and setting of the overlay position (composite position) of the foreign object sample image Sp on the X-ray absorption image Wp of the inspection object W Including various keys (key switches, cursor keys, function keys, arrow keys, numeric keys, etc.) and switches for giving various settings and instructions regarding foreign object detection of the inspection object W.

  Here, various modes will be briefly described. The various modes in this example are “foreign material sample inspection mode”, “operation check mode”, “foreign material sample storage mode”, and “operation mode”. The “foreign matter sample inspection mode” is a mode for inspecting whether or not foreign matter in the composite image Cp obtained by combining the foreign matter sample image Sp with the X-ray absorption image Wp of the inspection object W can be detected. The “operation confirmation mode” is a mode for confirming whether or not foreign matter detection by the optimum filter processing selected in the “foreign matter sample inspection mode” can be normally performed. In the “foreign matter sample storage mode”, the user conveys a desired foreign matter, checks whether or not the foreign matter can be detected, and stores information on the foreign matter and the foreign matter sample image Sp of the foreign matter sample image generation unit 6 to be described later. This is a mode for storing in 6a. The “operation mode” is a normal operation mode and is a mode for inspecting whether or not foreign matter is mixed in the inspection object W.

  The detection unit 4 includes an X-ray generator 4a and an X-ray detector 4b. The X-ray generator 4a has a configuration in which a cylindrical X-ray tube provided inside a metal box is immersed in insulating oil, and an X-ray is irradiated by irradiating an anode target with an electron beam from the cathode of the X-ray tube. Is generated. The X-ray tube is provided so that its longitudinal direction is orthogonal to the conveyance direction of the inspection object W. X-rays generated by the X-ray tube are exposed to a lower X-ray detector in the form of a substantially triangular X-ray through a slit along the longitudinal direction. It has become.

  The X-ray output conditions (X-ray tube voltage and tube current) can be arbitrarily set from the operation input unit 3 according to the characteristics of the inspection object W and the conveyance speed, or can be fixed values.

  The X-ray detector 4b detects X-rays transmitted through the inspection object W when the X-rays are exposed to the inspection object W, and according to the detected X-ray transmission amount. An electrical signal is being output. In the X-ray detector 4b, for example, a plurality of photodiodes arranged in a line in a direction perpendicular to the conveyance direction of the inspection object W conveyed on the belt conveyor forming the conveyance unit 2, and provided on the photodiodes An arrayed line sensor including the scintillator is used.

  In the detection unit 4, when the X-ray generator 4a emits X-rays to the inspection object W, the X-rays transmitted through the inspection object W are converted into the scintillator of the X-ray detector 4b. Is received and converted to light. Further, the light converted by the scintillator is received by the photodiode of the X-ray detector 4b disposed below the scintillator. Each photodiode converts the received light into an electrical signal and outputs it (detection output).

  A position detection unit 11 for detecting the passage of the inspection object W is provided on the carry-in side of the conveyance unit 2. The position detection unit 11 is configured by a photosensor including, for example, a pair of projectors and receivers, which is provided on the entrance side of a belt conveyor as the transport unit 2. As a result, while the inspection object W is passing in front of the photosensor, an ON signal is output from the position detection unit 11, and the rise of this ON signal is used as a timing signal.

  The X-ray transmission amount based on the electrical signal from the X-ray detector 4b relating to the inspection object W or the foreign matter prepared by the user is used to determine the inspection object W or the foreign matter prepared by the user based on the timing signal from the position detection unit 11. The X-ray absorption amount absorbed is converted into an X-ray absorption amount, and X-ray absorption images of the inspected object W and foreign matter obtained by this conversion are sequentially stored in the image storage unit 5, and various processes are executed.

  The image storage unit 5 obtains the X-ray transmission amount in the X-ray transmission image of the inspection object W based on the detection output of the X-ray detector 4b by converting it into the X-ray absorption amount absorbed by the inspection object W. The X-ray transmission amount in the X-ray transmission image of the foreign matter based on the X-ray absorption image of the inspection object W or the detection output of the X-ray detector 4b when the foreign matter prepared by the user is conveyed is absorbed by the foreign matter. An X-ray absorption image of the foreign matter obtained by converting into an X-ray absorption amount is stored.

Here, the X-ray absorption amount will be described. The X-ray absorption image shows a two-dimensional distribution of the X-ray absorption amount T by the object, and the X-ray irradiation amount I ₀ (X-ray intensity) and the X-ray transmission amount I (after passing through the object). Intensity), the absorption rate of X-rays is μ, and the thickness of the transmitted object is d, the X-ray absorption amount T can be expressed as a natural logarithm from the law of attenuation (I / I ₀ = e to the power of −μd). Then, the following formula (1) is established.
T = (logI ₀ -logI) = μd (1)

The X-ray absorptance μ has the relationship of the following formula (2), where X-ray wavelength is λ, object density is ρ, atomic number is Z, and constant is C.
μ = λ ³ ρZC Formula (2)

Equation (1) indicates that the X-ray absorption amount is the difference between the logarithmically converted X-ray irradiation amount I ₀ and the X-ray transmission amount I, and the X-ray irradiation amount I ₀ is the X-ray irradiation amount. This is the amount of X-ray transmission when the amount of absorption is zero. That is, the X-ray transmission amount I ₀ detected when there is no object to be inspected on the conveyor belt.

  Therefore, the X-ray absorption amount of the inspection object is logarithmically converted from the X-ray transmission amount detected in the absence of the inspection object on the conveyor belt and the X-ray transmission amount detected in the presence of the inspection object. It can be obtained from the difference between the obtained values.

  Similarly, for the foreign material sample, the difference between the values obtained by logarithmically converting the X-ray transmission amount detected in the absence of the inspection object on the conveyor belt and the X-ray transmission amount detected in the presence of the foreign material sample, respectively. Can be sought.

  On the other hand, the wavelength of X-rays depends on the tube voltage of the X-ray generator 4a (voltage applied to the X-ray tube), and the amount of X-ray irradiation depends on the tube current of the X-ray generator 4a. For example, the shorter the X-ray wavelength (the higher the tube voltage), the smaller the X-ray absorption amount. Therefore, as can be seen from the formulas (1) and (2), the degree to which the X-ray absorption amount fluctuates for each article (inspection object and foreign matter) having different densities and atomic numbers by varying the X-ray wavelength. Is different. In the X-ray foreign matter detection apparatus 1, the X-ray output conditions (X-ray tube voltage and tube current) of the X-ray generator 4a are set so that a difference between the inspection object W and the foreign matter is obtained using this fact. It is like that.

And the foreign material sample image (X-ray absorption image of a foreign material) detected on the basis of predetermined X-ray output conditions (X-ray tube voltage and tube current) stored in the storage means 6a of the foreign material sample image generation unit 6 to be described later ) S1, X-ray absorption image of the inspection object W acquired based on the X-ray output conditions (X-ray tube voltage and tube current) of the X-ray generator 4a set corresponding to the inspection object W Is S2, the composite image S is expressed by the following equation (3).
S = αS1 + S2 (where α is a conversion factor) (3)

  The conversion coefficient α in the above formula (3) is stored in the foreign substance sample image generation unit 6 serving as a reference for the density of the foreign substance sample image acquired for each X-ray output condition (X-ray tube voltage and tube current), for example. The ratio of the foreign matter sample image detected based on the predetermined X-ray output condition (X-ray tube voltage and tube current) stored in the means 6a is obtained in advance, and the X-ray output condition (X-ray tube voltage) And tube current) are stored in the conversion table.

  The foreign material sample image generation unit 6 generates X-ray absorption images of a plurality of foreign material samples having different sizes detected based on predetermined X-ray output conditions (X-ray tube voltage and tube current) set in advance. It is generated as Sp.

  In addition, the foreign object sample image generation unit 6 performs, for each type of foreign object when X-rays are irradiated under predetermined X-ray output conditions (X-ray tube voltage and tube current), that is, the shape (including size) and material ( For example, the storage unit 6a stores a foreign object sample image Sp for each metal or glass. This foreign object sample image Sp is converted into an X-ray absorption amount when an X-ray transmission amount is irradiated to a single foreign object under predetermined X-ray output conditions (X-ray tube voltage and tube current) set in advance. X-ray absorption image, in which foreign objects of different shapes (for example, corners, spheres, lines, etc.) and the same material (for example, metal, glass, resin, bones, etc.) are linearly arranged at a predetermined interval And an X-ray absorption image obtained by converting an X-ray transmission amount when X-rays are irradiated under predetermined X-ray output conditions (X-ray tube voltage and tube current) into an X-ray absorption amount.

  Of the foreign material sample images Sp stored in the storage unit 6a, the foreign material sample image set from the operation input unit 3 is a foreign material master serving as a reference for processing when the processing unit 7a described later performs processing. Can be used as

  When the “foreign material sample inspection mode” is selected and input from the operation input unit 3, the image composition unit 7, as shown in the conceptual diagram of FIG. 2, the X-ray image (X-ray absorption image) Wp of the inspection object W And the foreign substance sample image Sp of the type and size of the foreign substance set from the operation input unit 3 are superimposed and synthesized at a predetermined position, and the synthesized image Cp is output to the image processing unit 7.

  Here, the contents of the image composition processing by the image composition unit 7 will be described in more detail. In the image composition unit 7, when the X-ray absorption image Wp of the inspection object W and the foreign material sample image Sp are synthesized, the foreign material sample image corresponding to the type and size of the foreign material set from the operation input unit 3. A density conversion process is performed to convert the density of the foreign object sample image Sp read from the generation unit 6 into a density that matches the currently set X-ray output conditions (X-ray tube voltage and tube current). Thereafter, the image composition unit 7 executes density conversion processing for both the X-ray absorption image Wp and the foreign material sample image Sp.

  The density level of the X-ray absorption image of the inspection object W (product) varies logarithmically with the thickness of the inspection object W (product). For this reason, normally, when an X-ray absorption image is subjected to image processing, the change is corrected by performing logarithmic conversion of light and shade levels.

  Accordingly, the foreign matter sample image Sp synthesized with the X-ray absorption image Wp of the inspection object W is also corrected by changing the logarithm of the gray level when performing image processing according to the luminance of the inspection object W. doing.

For example, in the case of the example shown in FIG. 3, the density level of the object W is calculated based on the following equations (4) and (5) where log is a natural logarithm and exp {} is an exponential function with e as the base. Is done.
Light / dark level of inspection object W = 15 × log (thickness) −14 (Formula (4))
Thickness of inspection object W = exp {(light / dark level + 14) / 15} (5)

  Specifically, in the case of synthesizing a foreign object sample image Sp having a density level of 10 with no inspection object W in place of the thickness of the inspection object W and the density level of the inspection object W shown in FIG. Corrects the brightness of the foreign object signal of the foreign object sample image Sp by the above formulas (4) and (5), and synthesizes the X-ray absorption image Wp of the inspection object W.

  More specifically, when the density level of the inspection object W is 20, the thickness of the inspection object W is 10 mm according to the equation (5). The foreign matter signal of the foreign matter sample image Sp has the same value regardless of the thickness of the inspection object W. Therefore, a value obtained by multiplying the foreign matter signal by the thickness conversion coefficient is obtained as a pseudo foreign matter thickness (= conversion coefficient × foreign matter density signal level). ).

  Here, when the conversion coefficient is set to 0.5, the pseudo thickness of the foreign matter density level of 10 is 5 mm, and the foreign matter signal of 5 mm is added to the thickness of 10 mm calculated from the equation (5) to obtain a composite thickness of 15 mm. .

  By substituting this into equation (4), the gray level 26 of the foreign matter signal portion is obtained. Since the original foreign matter signal density level is 10 and the density level of the inspection object W is 20, the foreign substance signal itself is calculated by being multiplied by about 0.6.

  Similarly, when the thickness of the inspection object W is 20 mm, a signal multiplied by about 0.33 is combined, and when the thickness of the inspection object W is 40 mm, a signal increased by about 0.31 is combined.

  Then, with respect to the foreign matter (for example, metal, glass, wire, etc.) that the user wants to inspect, the foreign matter sample images Sp are detected by X-ray detection by arranging foreign matters having different sizes for each type as shown on the left side of the screen in FIG. By synthesizing the X-ray absorption image Wp of the inspection object W stored in the image storage unit 5 from the device 4b, it is possible to execute a foreign matter detection process for specifying a foreign matter that can be detected with respect to the foreign matter desired by the user. .

  The image processing unit 8 converts the transmission amount of X-rays transmitted through the inspection object W detected by irradiating the inspection object W to be conveyed with X-rays into the X-ray absorption amount absorbed by the inspection object W. The image processing for extracting the foreign matter is performed on the X-ray absorption image obtained in this way and the foreign matter sample composite image from the image composition unit 7, and the image processing result is output to the determination unit 9 and the display unit 10. .

  Further, the image processing unit 8 includes a foreign matter detection sensitivity estimation unit 8a and a foreign matter extraction unit 8b. The foreign object detection sensitivity estimation means 8a performs image processing on the foreign object sample composite image output from the image composition unit 6 for each type of foreign object, estimates the type of foreign object that can be detected based on the image processing result, and obtains the result. The data is output to the determination unit 9 and the display unit 10. Further, the foreign object detection sensitivity estimation means 8a applies a filter process prepared for each type of foreign object to the foreign object sample combined image from the image composition unit 6, and uses the filter process that can extract the smallest foreign object as an optimum filter. Selected.

  In the “foreign matter sample storage mode”, the foreign matter extracting means 8b sequentially applies the filter processing prepared for each type of foreign matter to the X-ray absorption image of the foreign matter stored in the image storage unit 5 for each filter processing. An image portion having a density exceeding the set foreign matter determination threshold is extracted as a foreign matter image, and the extraction result (extraction result for each position on the X-ray absorption image) is stored in the storage unit 6a of the foreign matter sample image generation unit 6. ing.

  The image processing unit 8 executes image processing described below according to the mode selected and input from the operation input unit 3.

  In the “foreign material sample inspection mode”, an image having a density exceeding the foreign object determination threshold set for each filter process by sequentially applying the filter process prepared for each type of foreign object to the composite image Cp from the image composition unit 7. Filter processing that can extract a part as a foreign object image and extract the smallest foreign object (if there is only one type of foreign substance: filter processing that can extract the smallest foreign object, if there are multiple types of foreign objects: the smallest foreign object for each type of foreign object Is selected as the optimum filter process.

  In the “operation check mode”, the X-ray absorption image Wp of the inspection object W from the image storage unit 5 is displayed in the image composition unit 7 for the type and minimum size of the foreign material that can be detected in the “foreign material sample inspection mode”. The optimum filter process selected in the “foreign material sample inspection mode” is executed on the synthesized image Cp, and the image processing result is output to the determination unit 9.

  In the “operation mode”, optimal filter processing is executed on the X-ray absorption image Wp of the inspection object W from the image storage unit 5, and the image processing result is output to the determination unit 9.

  The determination unit 9 includes the display control of the display unit 10 based on the estimation result by the foreign substance detection sensitivity estimation unit 8a of the image processing unit 8, and the contamination of the inspection object W based on the image processing result by the optimum filter processing of the image processing unit 8. Final determination of the presence / absence of an operation, determination of an operation check result in the “operation check mode”, display control of various determination results on the display unit 10, and the like.

  The display unit 10 is composed of, for example, a liquid crystal display or the like, and sets a product type that specifies the inspection object W by the operation input unit 3, sets X-ray output conditions (X-ray tube voltage and tube current), and various modes. Various setting screens such as the selection setting and setting of the overlapping position of the foreign object sample image Sp synthesized with the X-ray absorption image Wp of the inspection object W, and various displays based on the determination results by the determination unit 8 In addition to the X-ray transmission image / X-ray absorption image display of the inspection object W or the foreign matter prepared by the user, the pass / fail judgment display, the total number of inspections, the number of non-defective products, the number of NG) shown in the upper right of the screen in FIG.

  In addition to the above display, the display unit 10 displays the types and minimum sizes determined as foreign objects that can be detected as a result of the foreign object detection process for specifying the foreign objects in the foreign object sample inspection mode. Is displayed as a list. Further, on the screen of the display unit 10 (left side of the screen in FIG. 13), the list display and the X-ray absorption image Wp of the inspection object W and the foreign object sample image Sp used for specifying the detectable foreign object are displayed. The composite image is displayed, and the detected foreign material sample is highlighted (for example, black or red, or color-coded for each type of foreign material).

  Next, the configuration of the second embodiment of the X-ray foreign object detection device 1 according to the present invention will be described with reference to FIG. Note that in the X-ray foreign object detection device 1B of the second embodiment, the same reference numerals are given to substantially the same components as those of the X-ray foreign object detection device 1A of the first embodiment described above, and description thereof is omitted.

  In the X-ray foreign matter detection apparatus 1B of the second embodiment, the foreign matter sample image generation unit 6 generates the X-ray absorption image in accordance with the X-ray output conditions (X-ray tube voltage and tube current) when the X-ray absorption image is acquired. The image synthesizing unit 7 is provided with processing means 7a for processing the foreign object sample image by, for example, size conversion (enlargement / reduction conversion of the entire image, image length conversion) or density conversion.

  Note that the selection of the foreign material sample image to be processed and the setting of the size conversion rate and the density conversion rate are performed in advance from the operation input unit 3 before the synthesis process. In addition, the conversion rate of the size and density when converting the foreign object sample image is stored in advance, and a plurality of default values are stored in advance, and the default values are displayed on the display unit 10 by the operation from the operation input unit 3 and appropriately selected. It is also possible to change the default value arbitrarily.

  Here, the foreign matter master is foreign matter data stored in advance as a reference when processing the foreign matter sample image. Concentration conversion refers to conversion by thickness or generation conditions of X-rays to be irradiated. When the tube voltage is different, the wavelength (energy) of the generated X-rays is different and the absorption characteristics of the substance are changed. Therefore, density conversion is required for sensitivity estimation at a tube voltage different from the tube voltage when the foreign material master is stored.

  Next, each example in the case of synthesizing the foreign object sample image processed by the processing means 7a described above with the X-ray absorption image Wp of the inspection object W will be described with reference to FIGS.

  In the example of FIG. 5, the processing unit 7 a reads out the foreign material sample image set from the operation input unit 3 among the foreign material sample images Sp stored in the storage unit 6 a of the foreign material sample image generation unit 6 as a foreign material master SpM. The size of the foreign material master SpM is enlarged / reduced at a conversion rate of the size set from the operation input unit 3. In the example of FIG. 5, the foreign matter master SpM is enlarged / reduced and converted in two sizes. Then, the image synthesis unit 7 synthesizes the foreign object sample images Sp1 and Sp2 that have been enlarged / reduced and converted at these two types of conversion rates into the X-ray absorption image Wp of the object W to be inspected. The composite images Cp1 and Cp2 are output to the image processing unit 8.

  In the example of FIG. 6, the processing unit 7 a reads out the foreign substance sample image set from the operation input unit 3 among the foreign substance sample images Sp stored in the storage unit 6 a of the foreign substance sample image generation unit 6 as the foreign substance master SpM. The X-ray density of the foreign matter master SpM is converted at a density conversion rate set from the operation input unit 3. In the example of FIG. 6, the foreign matter master SpM is subjected to density conversion with two types of density. Then, the image synthesis unit 7 synthesizes the foreign substance sample images Sp3 and Sp4, which have been subjected to density conversion at these two types of density conversion ratios, with the X-ray absorption image Wp of the object W to be inspected, and two types of synthesized images Cp3. , Cp4 are output to the image processing unit 8.

  In the example of FIG. 7, the processing unit 7 a reads out the foreign substance sample image set from the operation input unit 3 among the foreign substance sample images Sp stored in the storage unit 6 a of the foreign substance sample image generation unit 6 as a foreign substance master SpM. The length (size) of the foreign matter master SpM is converted at the conversion rate of the length set from the operation input unit 3. In the example of FIG. 7, the foreign matter master SpM is changed in two types of lengths. Then, the image composition unit 7 composes the foreign object sample images Sp5 and Sp6 converted into these two types of lengths into the X-ray absorption image Wp of the inspection object W, respectively, and combines the two types of composite images Cp5 and Cp6. The image is output to the image processing unit 8.

  In the example of FIG. 8, the processing unit 7 a reads out the foreign substance sample image set from the operation input unit 3 among the foreign substance sample images Sp stored in the storage unit 6 a of the foreign substance sample image generation unit 6 as a foreign substance master SpM. The size of the foreign matter master SpM is converted at the conversion rate of the size set from the operation input unit 3. In the example of FIG. 8, the foreign matter master SpM is enlarged / reduced and converted in two sizes. Then, the image synthesis unit 7 synthesizes the foreign matter sample images Sp7 and Sp8 that have been enlarged / reduced at the conversion rates of these two sizes, and the synthesized foreign matter sample image Sp9 is used as the X of the object W to be inspected. The combined image Cp7 is output to the image processing unit 8 by combining with the line absorption image Wp.

  In the example of FIG. 9, the processing unit 7 a has a size set by the operation input unit 3 among the plurality of foreign sample images Sp stored for each type of foreign matter in the storage unit 6 a of the foreign sample image generation unit 6. One foreign object sample image Sp whose enlargement / reduction conversion rate is close to 1 is read as the foreign matter master SpM, and the size of the foreign matter master SpM is converted by the conversion rate. In the example of FIG. 9, one foreign matter sample image Sp is set as a foreign matter master SpM among the three types of foreign matter sample images Sp, and this foreign matter master SpM is enlarged / reduced and converted. Then, the image synthesis unit 7 synthesizes the foreign matter sample image Sp10 that has been subjected to the enlargement / reduction conversion, with the X-ray absorption image Wp of the inspection object W, and outputs the synthesis image Cp10 to the image processing unit 8.

  In the configuration example of FIG. 4, the processing unit 7 a has been described as performing the desired conversion using the foreign object sample image Sp as the foreign object master SpM. However, the foreign object sample that has been subjected to the desired conversion (size expansion / reduction conversion, density conversion). An image may be stored in the storage unit 6a in advance, and a foreign object sample image to be used may be selected and set from the operation input unit 3.

  Next, the operation for each mode (foreign matter sample inspection mode, operation confirmation mode, foreign matter sample storage mode, operation mode) of the X foreign matter detection apparatus 1 configured as described above will be described. Note that the “operation mode” is automatically selected when the apparatus is activated.

  First, the operation in the foreign material sample inspection mode will be described with reference to the flowcharts of FIGS. FIG. 10 is an operation flowchart by the filter processing optimization in the foreign matter sample inspection mode of the X-ray foreign matter detection device 1, and FIG. 11 is an operation flowchart by the filter processing fixation in the foreign matter sample inspection mode of the X-ray foreign matter detection device 1. In FIG. 10 and FIG. 11, the same step numbers are assigned to substantially the same operations.

Foreign object sample inspection mode In a state where the “foreign object sample inspection mode” is selected from the operation input unit 3, the object to be inspected W (non-defective product) is flowed by the transport unit 2 (ST1), and the X-ray output condition (X-ray generator 4a) (X2 tube voltage and tube current) are determined (ST2). The processing of ST2 is unnecessary when the X-ray output is fixed and the foreign object sample image Sp obtained under the same conditions as the X-ray output conditions (X-ray tube voltage and tube current) is used.

  Next, the foreign material sample image Sp is read from the foreign material sample image storage means 5b (ST3), and the foreign material sample image Sp is converted according to the X-ray output conditions (X-ray tube voltage and tube current) (ST4). That is, the density conversion processing of the foreign object sample image Sp is performed so as to meet the X-ray output conditions (X-ray tube voltage and tube current). The process of ST4 is an unnecessary process when the X-ray output is fixed and the foreign object sample image Sp obtained under the same conditions as the X-ray output conditions is used.

  Next, after performing the above-described density conversion processing on both the foreign object sample image Sp and the X-ray absorption image Wp of the inspection object W, the foreign object sample image Sp is converted into a predetermined position of the X-ray absorption image Wp of the inspection object W. (ST5). This synthesis process is executed by determining the synthesis position P according to any of the brute force scanning method, density distribution (histogram), or user designation. Hereinafter, a method for determining the composite position P will be described.

  In the brute force scan method, the X-ray absorption image Wp of the object W to be inspected is scanned every predetermined area from end to end, and all the areas (all pixels or pixel groups) on the X-ray absorption image Wp are scanned. A synthesis process is performed as the synthesis position P.

  In the density distribution (histogram), for example, when the X-ray absorption image Wp of the inspection object W shows the density distribution as shown in FIGS. 12A and 12B, the density distribution shown in FIG. The synthesis position P of the foreign object sample image Sp is determined to perform synthesis processing as shown in any one of (e) to (e).

  In the example of FIG. 12C, the composite positions P are determined at several places (two places in the illustrated example) in the background (belt density) region of the X-ray absorption image Wp of the inspection object W.

  In the example of FIG. 12D, the lattice-shaped composite position P is determined in a region where the density of the X-ray absorption image Wp of the inspection object W is low.

  In the example of FIG. 12E, the composite position P is determined at a plurality of locations in the region where the density of the X-ray absorption image Wp of the inspection object W is high (in the illustrated example, each of the three regions with high density). ing.

  In the user designation, for example, on the designation screen for the synthesis position P of the foreign object sample image Sp on the display unit 9 as shown in FIG. 14, the user synthesizes an arbitrary position from the X-ray absorption image Wp of the inspection object W as the synthesis position P. Processing is in progress. In FIG. 14, “metal” is selected from the types of foreign material samples “metal, glass, wire” that can be specified, and four locations (dotted line square portion P) on the X-ray absorption image Wp of the inspection object W on the left side of the screen are displayed. An example in which the combination position is designated is shown. If the composite position P is determined by this user designation, only the portion desired by the user can be determined as the composite position P, and an efficient inspection of foreign matter detection accuracy can be performed.

  Next, for the synthesized image Cp synthesized in ST5 by determining the synthesis position P described above, one filter process is set from the filter processes prepared for each type of foreign matter, and the set filter process is executed. The foreign matter is extracted and the extraction result is stored (ST6). In the process of ST6, the difference between the X-ray absorption image Wp of the inspection object W and the composite image Cp is detected so that foreign matter can be detected even if the X-ray absorption image of the inspection object W by the non-defective product has density variations. Based on this, a foreign substance determination limit is set for each filter process. And it is discriminate | determined by the foreign material determination limit of the set filter process whether it was able to be extracted as a foreign material from the synthesized image Cp, and the result is memorize | stored.

  It should be noted that the foreign matter extraction possibility and the foreign matter extraction rate (number of extractables / total number of combined positions) for each place on the composite image Cp are determined (determination based on ○, Δ, ×, etc.), and the result may be stored. . Further, in the operation of fixing the filter process according to FIG. 11, in ST6, the filter process set in advance is executed to extract the foreign matter, and the extraction result is stored.

  Next, it is determined whether or not it is the last combining position P (ST7). If it is not the last combining position P (ST7-No), the process returns to ST5. On the other hand, if it is determined that it is the last composite position P (ST7-Yes), it is determined whether or not the foreign material sample image Sp is the last size (ST8). If it is determined that the foreign object sample image Sp is not the last size (ST8-No), the process returns to ST3. On the other hand, if it is determined that the foreign object sample image Sp is the last size (ST8-Yes), it is determined whether or not it is the last foreign object sample image Sp (ST9), and if it is determined that it is not the last foreign object sample image Sp. (ST9-No), the process returns to ST3.

  If it is determined that the sample is the last foreign object sample image Sp (ST9-Yes), the optimum filter process is selected from the already executed filter processes (ST10). As this optimal filter processing, the filter processing that can extract the smallest foreign matter (if there is one type of foreign matter: the filter processing that can extract the smallest foreign matter, if there are multiple types of foreign matter: the smallest foreign matter for each type of foreign matter Is selected).

  When the optimum filter processing is selected (ST10), the size of foreign matter that can be detected by this optimum filter processing is estimated (ST11), and the result of foreign matter extraction is displayed on the display unit 10 in the form shown in FIG. Display (ST12). In the example of FIG. 13, metal: φ1, resin: φ2, glass: φ4, and wire: φ1 × 3 are displayed as the types and minimum sizes of foreign matters that can be detected.

  In the operation of fixing the filter process in FIG. 11, the process of ST10 in FIG. 10 is omitted, the size of the foreign object that can be detected by the preset filter process is estimated (ST11), and the result of the foreign object extraction is shown in FIG. Is displayed on the display unit 10 in the format as shown in FIG.

Operation Confirmation Mode When “Operation Confirmation Mode” is selected from the operation input unit 3, the image processing unit 8 stores an image for the types and minimum sizes of foreign matters that can be detected in the “foreign matter sample inspection mode” described above. The optimum filter processing selected in the “foreign material sample inspection mode” is executed on the composite image Cp obtained by combining the X-ray absorption image Wp of the inspection object W from the unit 5 in the image combining unit 7. The determination unit 9 can detect in the “foreign matter sample inspection mode” based on the image processing result of the image processing unit 8 and the foreign matter determination threshold value corresponding to the optimum filter processing selected in the “foreign matter sample inspection mode”. It is determined whether or not the detection of all types of foreign matter and the minimum size foreign matter has been successfully performed. Thereby, it can be confirmed whether or not the foreign matter detection by the optimum filter processing selected in the “foreign matter sample inspection mode” operates normally.

Foreign object sample storage mode When the foreign object sample storage mode is selected from the operation input unit 3 and a desired foreign object is transferred from the transfer unit 2, X-rays are emitted to the foreign object. An X-ray absorption image of the foreign matter accompanying the irradiation is stored in the image storage unit 5. When the foreign matter extraction means 8b of the image processing unit 8 extracts the foreign matter X-ray absorption image stored in the image storage unit 5 as a foreign matter by a predetermined filtering process, the foreign matter information and the X-ray absorption image are extracted. Is stored in the storage means 6a of the foreign object sample image generation unit 6. This makes it possible to register the foreign substance detection sensitivity and foreign substance information (foreign substance sample image) desired by the user.

-Operation mode When "operation mode" is selected from the operation input unit 3, X-rays are irradiated to the inspection object W sequentially conveyed from the conveyance unit 2, and X of the inspection object W accompanying the irradiation of the X-rays. The line absorption image Wp is stored in the image storage unit 5. Then, the image processing unit 8 converts the X-ray transmission amount into the X-ray absorption amount absorbed by the inspection object W, and the X-ray absorption image Wp of the inspection object W stored in the image storage unit 5. Execute the selected optimum filtering process. Then, the determination unit 9 determines the presence or absence of foreign matter based on the image processing result of the image processing unit 8 and the foreign matter determination threshold value corresponding to the selected optimum filter processing, and displays the determination result on the display unit 10. To do.

  As described above, according to the X-ray foreign object detection device of this example, X-ray absorption images of a plurality of different foreign object samples detected based on predetermined X-ray output conditions (X-ray tube voltage and tube current). Is stored as a foreign object sample image, and this foreign object sample image is combined with the X-ray absorption image of the inspection object, so that a transmission image when the foreign object is mixed into the inspection object without using an actual foreign object sample is stored. Can be estimated and the size of the detectable foreign matter can be estimated.

  A plurality of types of foreign matter sample images are stored in the storage means 6a of the foreign matter sample image generation unit 6, and the respective foreign matter sample images are combined with the X-ray absorption image of the object to be inspected. If the filter processing prepared in step 2 is performed to determine whether foreign matter can be extracted, and the optimal filter processing is determined from the determination result, a plurality of filter processings that can detect foreign matter with high sensitivity can be actually detected. It can be set without trial using a foreign material sample.

  The storage unit 6a of the foreign material sample image generation unit 6 stores foreign material sample images (X-ray absorption images) for each type and size of foreign materials, that is, foreign material sample images corresponding to foreign materials having different materials, shapes, and sizes. . Thereby, the range of the size that can be extracted as a foreign object from the inspection object according to the type (variety) of the inspection object can be estimated for each material and shape of the foreign object.

  In the foreign matter sample storage mode, an X-ray absorption image of an arbitrary foreign matter desired by the user can be registered and stored in the storage means 6a as a foreign matter sample image, and the X-ray absorption image of the foreign matter for any foreign matter prepared by the user is stored as a foreign matter sample. An X-ray absorption image of the inspection object can be synthesized as an image, and it can be estimated whether it can be extracted as a foreign object.

  Based on the X-ray generator X-ray output conditions (X-ray tube voltage and tube current) optimally set according to the characteristics of the object to be inspected and the conveyance speed, the concentration of the stored X-ray absorption image is determined. It is converted. Thereby, even when the density of the X-ray absorption image of the object to be inspected changes, the foreign object sample image can be synthesized with an appropriate density, and the estimation of whether or not it can be extracted as a foreign object can be made more accurate.

  Since information on the foreign matter that can be detected is displayed on the display unit 9 based on the determination result of whether or not the composite image includes foreign matter, the device can be checked by directly checking the contents of the display unit 9. Information on detectable foreign matter can be grasped.

  By specifying and setting the composite position of the foreign object sample image on the X-ray transmission image of the inspection object displayed on the display unit 9, the foreign object sample that has been conventionally implemented is actually attached to each position of the inspection object. Similarly to the confirmation, the foreign object sample image can be synthesized at a predetermined position determined by the user.

  If the composition position of the foreign object sample image is set from the density distribution of the X-ray transmission image of the inspection object, the calculation amount and calculation time can be reduced by narrowing down the position where the foreign object sample image is combined according to the characteristics of the inspection object. Furthermore, it can be estimated appropriately whether a foreign material can be extracted.

  According to the configuration provided with the processing means 7a as shown in FIG. 4, the X-ray output conditions (X-ray tube voltage and X-ray output conditions) of the X-ray generator 4a that are optimally set according to the characteristics of the object to be inspected and the conveyance speed. Since the density of the foreign object sample image is processed based on the tube current), the foreign object sample image can be synthesized at an appropriate density even when the density of the transmission image of the inspection object changes, and extracted as a foreign object. The estimation of whether it can be made can be made more accurate.

  By the way, in embodiment mentioned above, the X-ray absorption image when the to-be-inspected object W and a desired foreign material are conveyed on the conveyance part 2 is memorize | stored in the image memory | storage part 5, and also by the X-ray absorption image of various foreign materials Although a configuration has been described in which the foreign sample image is generated by the foreign sample image generation unit 6 and the synthesis process is performed using these X-ray absorption images, the configuration is not limited to this configuration. For example, an X-ray transmission image when the inspection object W or a desired foreign object is transferred onto the transfer unit 2 is stored in the image storage unit 5, and a foreign object sample image is generated from X-ray transmission images of various foreign objects. When the image is generated by the unit 6 and processed by the image synthesis unit 7 or the image processing unit 8, the X-ray transmission image is converted into an X-ray absorption image, or the X-ray transmission image is used for the synthesis process. Is also possible. However, if the composition processing is performed using the X-ray absorption image, as shown in FIG. 15, the X-ray absorption image of the inspection object W and the foreign object sample image (the X-ray absorption image of the foreign object) can be combined starting from 0. Thus, it is possible to reduce the time and effort involved in the synthesis process compared to the case where an X-ray transmission image is used.

It is a block block diagram of 1st Embodiment of the X-ray foreign material detection apparatus which concerns on this invention. It is a conceptual diagram of the synthetic | combination process with the X-ray image of a to-be-inspected object, and a foreign material sample image in the X-ray foreign material detection apparatus which concerns on this invention. (A), (b) It is a figure which shows an example of the thickness and lightness level of to-be-inspected object in the X-ray foreign material detection apparatus which concerns on this invention. It is a block block diagram of 2nd Embodiment of the X-ray foreign material detection apparatus which concerns on this invention. It is a figure which shows the various examples of a synthesized image when processing (size conversion, density | concentration conversion) is given to one type of foreign material sample image, and it synthesize | combined with the to-be-inspected image. It is a figure which shows the various examples of a synthesized image when processing (size conversion, density | concentration conversion) is given to one type of foreign material sample image, and it synthesize | combined with the to-be-inspected image. It is a figure which shows the various examples of a synthesized image when processing (size conversion, density | concentration conversion) is given to one type of foreign material sample image, and it synthesize | combined with the to-be-inspected image. It is a figure which shows the example of a synthesized image when what synthesize | combined by performing processing (size conversion) to one kind of foreign material sample image, and was further synthesize | combined with the to-be-inspected image. It is a figure which shows the example of a synthetic | combination image when selecting one type of foreign material sample image from a plurality of types of foreign material sample images, performing processing (size conversion), and synthesizing with an inspection object image. It is an operation | movement flowchart by the filter process optimization at the time of the foreign material sample inspection mode of the X-ray foreign material detection apparatus which concerns on this invention. It is an operation | movement flowchart by the filter process fixation at the time of the foreign material sample inspection mode of the X-ray foreign material detection apparatus which concerns on this invention. (A)-(e) It is explanatory drawing regarding the process which determines a synthetic | combination position from density distribution in the X-ray foreign material detection apparatus which concerns on this invention. It is a figure which shows the example of a display of the X-ray foreign material detection apparatus which concerns on this invention. It is explanatory drawing in the case of setting manually the synthetic | combination position of a foreign material sample image in the X-ray foreign material detection apparatus which concerns on this invention. It is explanatory drawing regarding the absorbency of the X-ray in the case where a foreign material is synthesize | combined to a to-be-tested object, and the case of only a foreign material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray foreign material detection apparatus 2 Conveyance part 3 Operation input part 4 Detection part 4a X-ray generator 4b X-ray detector 5 Image storage part 6 Foreign material sample image generation part 6a Storage means 7 Image composition part 8 Image processing part 8a Foreign object detection Sensitivity estimation means 8b Foreign matter extraction means 9 Judgment section 10 Display section 11 Position detection section W Inspected object Wp X-ray absorption image of inspected object Sp Foreign object sample image Cp Composite image P Composite position

Claims (7)

Image processing for extracting foreign matter is performed on an X-ray image based on an X-ray transmission amount detected by transmitting through the inspection object when the object to be inspected (W) is irradiated with X-rays. An X-ray foreign object detection device (1) comprising an image processing unit (8) for performing determination of whether or not a foreign object is contained in the inspection object based on an image processing result of the image processing unit;
A foreign matter sample image generation unit (6) for generating X-ray images of a plurality of foreign matter samples having different sizes detected based on predetermined X-ray output conditions as foreign matter sample images;
An image composition unit (7) for outputting a composite image in which the foreign material sample image generated by the foreign material sample image generation unit is superimposed on the X-ray image at a plurality of positions;
As a result of image processing of a plurality of foreign substance sample composite images output from the image composition unit, detection is performed based on a foreign substance extraction rate extracted as a foreign substance among the plurality of positions where the foreign substance sample images are superimposed. A foreign matter detection sensitivity estimation means (8a) for estimating the size of a possible foreign matter ;
An X-ray foreign object detection apparatus comprising: a display unit (10) for displaying a size of a detectable foreign object estimated by the foreign object detection sensitivity estimation means and the foreign object sample composite image . The foreign material sample image generation unit (6) includes a storage unit (6a) for storing foreign material sample images of a plurality of types of foreign materials detected based on the predetermined X-ray output conditions,
The X-ray foreign object detection device according to claim 1, wherein the foreign object detection sensitivity estimation means (8a) estimates the size of a foreign object that can be detected for each type of foreign object. The foreign object detection sensitivity estimation means (8a) performs a filter process prepared for each type of foreign object on the composite image, and selects a filter process that can extract the smallest foreign object as an optimum filter. The X-ray foreign material detection apparatus according to claim 2. Processing means (7a) for converting the density of the foreign material sample image generated by the foreign material sample image generation unit (6) in accordance with the X-ray output condition when the X-ray image is acquired,
The said image synthetic | combination part (7) outputs the synthesized image which superimposed the foreign material sample image converted by the said process means on the said X-ray image in a desired position. The X-ray foreign material detection apparatus of any one of Claims. The X-ray image obtained when a desired foreign substance is conveyed under a predetermined X-ray output condition is registered and stored in the storage means (6a) as a foreign substance sample image related to the foreign substance. The X-ray foreign material detection apparatus of any one of Claims 1-4. The display unit (10) for displaying a transmission image of the inspection object (W) is provided, and a synthesis position of the foreign object sample image is designated on the transmission image displayed on the display unit. The X-ray foreign material detection apparatus according to any one of claims 5 to 6. The composite position of the foreign object sample image with respect to the transmission image is determined based on the density distribution of the transmission image of the inspection object (W). X-ray foreign object detection device.

Images