JP2013064613A - X-ray inspection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray inspection apparatus capable of determining whether a product is filled with a suitable quantity of articles and granular substances.SOLUTION: An X-ray irradiator 21 irradiates an object to be inspected containing articles and granular substances with X rays. An X-ray line sensor 22 detects X rays transmitted through the object to be inspected. An image generation section 82a generates an X-ray image in accordance with the amount of transmitted X rays detected by the X-ray line sensor 22. A dark part identification section 82b identifies a dark part having a predetermined gradation value in the X-ray image on the basis of a first threshold value. A first determination section 82c determines a right amount of articles on the basis of a total area of dark parts included in the X-ray image and a second threshold value.

Description

  The present invention relates to an X-ray inspection apparatus.

  Conventionally, a combination weighing instrument has been used to fill a bag with a target weight to be packaged (such as confectionery). The combination weighing instrument has a plurality of weighing units. The objects to be weighed are distributedly supplied to a plurality of weighing units. The target object to be packaged can be obtained by combining the weights of the objects to be weighed supplied to the plurality of weighing units.

  By the way, for example, when the package includes an article fried in oil such as potato chips and a seasoning (powder) added to the article, the total amount of the package to be filled in the bag is determined. In addition to setting the value within the specified range, it is desirable that the amount of seasoning in the total weight is a value within the specified range. That is, it is necessary that the articles and seasonings filled in the bag have appropriate amounts. In particular, when handling an article such as potato chips, the seasoning may accumulate and adhere to the measuring section due to the oil content of the article. Thus, for example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2004-93463) proposes a technique for preventing the fixation of seasoning in the measuring unit, thereby reducing the filling of the seasoning lump into the bag.

  However, in the above technique, since the amount of seasoning filled in the bag cannot be grasped, the seasoning weight in the total weight may deviate from the specified value.

  An object of the present invention is to provide an X-ray inspection apparatus capable of determining a product (a correct amount product) filled with an object to be packaged including an appropriate amount of seasoning.

  An X-ray inspection apparatus according to the present invention is an X-ray inspection apparatus for determining a right-quantity product in which a proper amount of an article and a granular material are packaged, and an X-ray irradiation unit, an X-ray detection unit, An image generation part, a dark part specific | specification part, and a 1st determination part are provided. The X-ray irradiation unit irradiates the inspection object including the article and the granular material with X-rays. The article has a first X-ray transmission. The granular material has a second X-ray transmission different from the first X-ray transmission. The X-ray detection unit detects X-rays that have passed through the inspection object. The image generation unit generates an X-ray image according to the intensity of the transmitted X-ray detected by the X-ray detection unit. The dark part specifying part specifies the dark part based on the first threshold value. The dark part is a part having a predetermined gray value in the X-ray image. The first determination unit determines a positive-quantity product based on the total area of the dark part included in the X-ray image and the second threshold value.

  Thereby, it can be recognized that the inspected object contains an amount of fine particles that deviate from the specified value (appropriate amount value).

  Moreover, it is preferable that an X-ray inspection apparatus is further provided with a 1st memory | storage area | region, a shading peak value specific | specification part, and a 2nd determination part. The first storage area stores a reference light / dark peak value. The reference light and shade peak value is the peak value of the light and shade value of the X-ray image related to the positive quantity product. The light / dark peak value specifying unit specifies the target light / dark peak value. The target grayscale value is a peak value of the grayscale value of the X-ray image generated by the image generation unit. A 2nd determination part determines a right-quantity product based on a reference | standard lightness peak value and object lightness / darkness peak value.

  As a result, it is possible to determine the case where the amount of the particulate matter that deviates from the specified value is gathered inside the bag or thinly spread inside.

  Furthermore, the reference light / dark peak value is a range of the reference light / dark peak value determined based on the X-ray images for a plurality of positive-quantity products, and the second determination unit determines whether or not the target light / dark peak value is included in the range. Is preferably determined.

  Thereby, the state of the granular material inside the bag can be determined in more detail.

  The X-ray inspection apparatus preferably further includes a gap equivalent amount determination unit and a third determination unit. The gap equivalent amount determination unit determines the gap equivalent amount. The gap-corresponding amount is determined based on the gray value difference of the pixels constituting the X-ray image. The pixel gray value difference is a difference between the gray value of the first pixel constituting the X-ray image and the gray value of an adjacent pixel adjacent to the first pixel. The third determination unit determines a positive-quantity product based on the gap equivalent amount included in the X-ray image.

  Thereby, a right-quantity product can be judged in consideration of the quantity of the granular material of the state diffused inside the bag.

  Furthermore, it is preferable that the X-ray inspection apparatus further includes a third threshold value storage area and a gap related information storage area. The third threshold storage area stores a third threshold. The third threshold value is a threshold value related to the gray value difference. The gap related information storage area stores gap equivalent amount determination values. The gap equivalent amount determination value is a value for determining whether or not the gap equivalent amount included in the X-ray image is appropriate. The gap equivalent amount determination unit preferably determines the total amount of gap equivalent amounts included in the X-ray image based on the third threshold value. Moreover, it is preferable that a 3rd determination part determines whether the total amount of clearance equivalent amount is contained in a predetermined range based on a clearance equivalent amount determination value.

  As a result, it is possible to more accurately determine a positive-quantity product.

  The X-ray inspection apparatus according to the present invention makes it possible to determine a product (a correct amount product) filled with an object to be packaged including an appropriate amount of seasoning.

1 is an external perspective view of an X-ray inspection apparatus according to an embodiment of the present invention. 1 is a schematic view of an inspection line (X-ray inspection system) including an X-ray inspection apparatus. It is a simple block diagram inside the shield box of an X-ray inspection apparatus. It is a graph which shows the example of the transmission amount of the X-ray detected by an X-ray detection element. It is a control block diagram which shows the structure of the control apparatus with which an X-ray inspection apparatus is provided. It is a figure which shows X-ray image A (positive-quantity goods). It is a figure which shows X-ray image B (mixed goods 1). It is a figure which shows X-ray image C (mixed goods 2). It is a figure which shows the dark part area, X-ray peak value, gap | interval equivalent amount, and determination result regarding X-ray image AC. It is a graph for demonstrating a shading peak value. It is the elements on larger scale of the X-ray image for demonstrating determination of clearance gap equivalent amount. It is a conceptual diagram for demonstrating the filter coefficient used for determination of clearance gap equivalent amount. It is a conceptual diagram for demonstrating the determination process of clearance gap equivalent amount. It is a flow for demonstrating the process which concerns on determination of a seasoning amount. It is a flow for demonstrating the process which concerns on determination of a seasoning amount. It is a flow for demonstrating the process which concerns on determination of a seasoning amount. It is a flow for demonstrating the process which concerns on determination of a seasoning amount. It is a flow for demonstrating the process which concerns on determination of a seasoning amount. It is a figure which shows the example of the X-ray inspection apparatus shown to the modification H. It is a figure which shows the example of the X-ray inspection apparatus shown to the modification I. It is a figure which shows the example of the X-ray inspection apparatus shown to the modification I.

  Hereinafter, an X-ray inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(1) Schematic description of X-ray inspection apparatus FIG. 1 is a perspective view showing an appearance of an X-ray inspection apparatus 10 according to an embodiment of the present invention. FIG. 2 shows an example of an inspection line (X-ray inspection system) 100 in which the X-ray inspection apparatus 10 is incorporated. In the inspection line, the product G such as confectionery is inspected. The product G is, for example, a product (bag 60) in which an article 50 such as potato chips or pretzel and a seasoning (seasoning) (powder) added to the article 50 are packaged. . The article 50 is massive and has a larger area and volume than seasoning. In other words, the article 50 is, for example, baked and hardened potato, flour or the like, and is mainly composed of carbohydrates. On the other hand, seasoning is mainly composed of a substance containing chlorine (for example, salt (NaCl)) or a substance that easily absorbs X-rays. The total weight of the items to be packaged is weighed to a predetermined weight using a combination weighing device (not shown) and filled in the bag 60.

  In addition to the X-ray inspection apparatus 10, the inspection line 100 includes an upstream conveyor unit 71 and a distribution mechanism 72. The upstream conveyor unit 71 is provided upstream of the X-ray inspection apparatus 10. The upstream conveyor unit 71 continuously sends the product G to the X-ray inspection apparatus 10. The X-ray inspection apparatus 10 determines the quality of the product G by irradiating the product G continuously conveyed by the upstream conveyor unit 71 with X-rays. The result determined by the X-ray inspection apparatus 10 is transmitted to a distribution mechanism 72 arranged on the downstream side of the X-ray inspection apparatus 10. The distribution mechanism 72 is connected to the line conveyor unit 73 and the defective product collection line 74. The distribution mechanism 72 distributes the product G determined to be a non-defective product (correct product) in the X-ray inspection apparatus 10 to the line conveyor unit 73, and distributes the product G determined to be defective to the defective product collection line 74.

  The X-ray inspection apparatus 10 according to the present embodiment determines whether the ratio of the article 50 and the seasoning 52 filled in the bag 60 of the product G is within a specified range. In other words, the X-ray inspection apparatus 10 determines whether or not the amount of seasoning 52 included in the product G is an appropriate amount, and when the seasoning 52 is an appropriate amount, determines that the product G is a right-quantity product, If the seasoning 52 is not in an appropriate amount, it is determined that the product G is a defective product or a mixed product (that is, a product in which a lump of seasoning 52 is mixed). The defective product or the mixed product is a product G (see FIGS. 7 and 8) in which a larger amount of seasoning 52 is mixed in the bag 60 than the specified range. In other words, the product G is a product G in which the amount of the articles 50 contained in the bag 60 is less than the specified range.

(2) Detailed description of X-ray inspection apparatus As shown in FIG. 1 or FIG. 3, the X-ray inspection apparatus 10 mainly includes a shield box 11, a conveyor unit 12, and an X-ray irradiator (X-ray irradiation unit) 21. And an X-ray line sensor (X-ray detection unit) 22, a monitor 30 with a touch panel function, and a control device 80.

(2-1) Shield Box The shield box 11 is a box that houses a conveyor unit 12, an X-ray irradiator 21, an X-ray line sensor 22, a control device 80, and the like, which will be described later. In addition to the monitor 30, a key insertion slot, a power switch, and the like are disposed on the upper front portion of the shield box 11. Openings 11 a are formed on both side surfaces of the shield box 11. The opening 11a is used to carry the product G into and out of the shield box 11. The opening 11a is blocked by a shielding noren (not shown). The shield noren prevents X-rays inside the shield box 11 from leaking to the outside. The shielding nolen is molded from rubber containing lead. The shielding nolen is pushed away by the product G when the product G passes through the opening 11a.

(2-2) Conveyor unit The conveyor unit 12 conveys the product G within the shield box 11. As shown in FIG. 1, the conveyor unit 12 is disposed so as to penetrate through the openings 11 a formed on both side surfaces of the shield box 11. The conveyor unit 12 mainly includes an endless belt, a driving roller, and a conveyor motor 12a (see FIG. 5). The driving roller is driven by the conveyor motor 12a. By driving the driving roller, the belt is rotated and the product G on the belt is conveyed downstream. The conveying speed of the product G by the conveyor unit 12 varies according to the set speed input by the operator. The control device 80 performs inverter control of the conveyor motor 12a based on the set speed, and finely controls the conveyance speed of the product G. The conveyor motor 12a is equipped with an encoder 12b (see FIG. 5) that detects the conveyance speed of the conveyor unit 12 and sends it to the control device 80.

(2-3) X-ray irradiator The X-ray irradiator 21 is disposed above the conveyor unit 12 as shown in FIG. The X-ray irradiator 21 irradiates the fan-shaped irradiation range X with X-rays toward the X-ray line sensor 22. The irradiation range X extends perpendicular to the transport surface of the conveyor unit 12. Further, the irradiation range X extends in a fan shape in a direction that intersects the transport direction of the conveyor unit 12. That is, the X-rays emitted from the X-ray irradiator 21 spread in the belt width direction.

(2-4) X-ray line sensor The X-ray line sensor 22 is arrange | positioned under the conveyor unit 12, as shown in FIG. 3 and FIG. The X-ray line sensor 22 is mainly composed of a large number of X-ray detection elements 22a. The X-ray detection elements 22a are horizontally arranged in a straight line in a direction orthogonal to the conveyance direction by the conveyor unit 12. Each X-ray detection element 22a detects X-rays transmitted through the product G and the conveyor unit 12, and outputs an X-ray transmission signal based on the detected X-rays. In other words, the X-ray transmission signal outputs an X-ray transmission signal corresponding to the intensity of the transmitted X-ray. The intensity of the transmitted X-ray varies depending on the magnitude of the transmitted X-ray dose (transmitted X-ray dose). The brightness (shading value) of the X-ray image is determined by the X-ray transmission signal (see FIG. 4). FIG. 4 is a graph showing an example of the amount of X-ray transmission detected by the X-ray detection element 22a of the X-ray line sensor 22. The horizontal axis of the graph corresponds to the position of each X-ray detection element 22a. The horizontal axis of the graph corresponds to the distance in the direction orthogonal to the conveying direction of the conveyor 12. Also, the vertical axis of the graph is the amount of X-ray transmission detected by the X-ray detection element 22a. A portion with a large amount of transmission is displayed as a bright (light) X-ray image, and a portion with a small amount of transmission is dark (dark). Displayed as an X-ray image. That is, the lightness (darkness) of the X-ray image corresponds to the amount of X-ray transmission.

  Furthermore, the X-ray line sensor 22 also functions as a sensor for detecting the timing when the product G as a specimen passes through the fan-shaped X-ray irradiation range X (see FIG. 3). That is, when the product G is conveyed by the conveyor unit 12 and reaches the upper position (irradiation range X) of the X-ray line sensor 22, the X-ray line sensor 22 transmits an X-ray transmission signal (first signal) indicating a voltage equal to or lower than a predetermined threshold. 1 signal) is output. On the other hand, when the product G passes the irradiation range X, the X-ray line sensor 22 outputs an X-ray transmission signal (second signal) indicating a voltage exceeding a predetermined threshold. The presence or absence of the product G in the irradiation range X is detected by inputting the first signal and the second signal to the control device 80 described later.

(2-5) Monitor The monitor 30 is a liquid crystal display. The monitor 30 displays a screen that prompts the operator to input inspection parameters and the like necessary for the inspection. The monitor 30 also has a touch panel function and accepts input of inspection parameters and the like from the operator.

(2-6) Control Device As shown in FIG. 5, the control device 80 mainly includes a storage unit 81 and a control unit 82. The storage unit 81 includes a ROM, a RAM, an HDD (hard disk), and the like. The control unit 82 is configured by a CPU.

  The control device 80 also includes a display control circuit, a key input circuit, a communication port, and the like (not shown). The display control circuit is a circuit that controls data display on the monitor 30. The key input circuit is a circuit that captures key input data input by an operator via the touch panel of the monitor 30. The communication port enables connection with an external device such as a printer or a network such as a LAN.

  The control device 80 is also connected to the conveyor motor 12a, the encoder 12b, the X-ray irradiator 21, the X-ray line sensor 22, and the like described above. The control device 80 acquires data related to the rotation speed of the conveyor motor 12a from the encoder 12b, and grasps the moving distance of the product G based on the data. Further, as described above, the control device 80 receives the signal output from the X-ray line sensor 22 to detect the timing when the article G on the belt of the conveyor unit 12 has come to the irradiation range X.

(2-6-1) Storage Unit The storage unit 81 stores various programs and inspection parameters to be executed by the control unit 82. The inspection parameters are input by the operator using the touch panel function of the monitor 30.

  The storage unit 81 mainly includes an X-ray image storage area 81a, a dark part information storage area 81b, a light / dark peak value related information storage area (first storage area) 81c, a boundary threshold storage area (third threshold storage area) 81d, and a gap relation. It has an information storage area 81e and a determination result storage area 81f.

(A) X-ray image storage area The X-ray image storage area 81a stores data (image data) related to an image generated by an image generation unit 82a described later. The image data includes information relating to the gray value of each pixel constituting the X-ray image.

(B) Dark Part Information Storage Area The dark part information storage area 81b stores information related to the dark part. The information related to the dark part includes a plurality of threshold data for determining the dark part included in the X-ray image and data related to the dark part area.

  The plurality of threshold data includes a first threshold and a second threshold.

  The first threshold value is a threshold value for specifying a dark pixel (dark part) from all the pixels constituting the X-ray image. The first threshold value is a predetermined gray value for the pixel. Specifically, the first threshold value is a value indicating which of the gradations (for example, 256) for classifying the gray values of all the pixels constituting the X-ray image to distinguish the bright part and the dark part. is there. In other words, the first threshold value is a threshold value for distinguishing between a portion with a large amount of X-ray transmission and a portion with a small amount of X-ray transmission. The first threshold is set according to the type of the article 50 and seasoning 52, respectively.

  The second threshold value is a threshold value for determining a positive product based on the total area of the dark part included in the X-ray image. In other words, the second threshold value includes the total number of pixels specified as the dark part (total area of the dark part) among all the pixels constituting the X-ray image in the X-ray image of the product G that is a positive quantity product. It is a threshold value for determining whether or not it is equal to the total area of the dark part. Note that the second threshold is set by the user based on the total area of the dark portions of the X-ray images related to the plurality of products G that have been determined to be positive products in the past. For example, when the total area of dark portions of a plurality of products G that have been determined to be positive products in the past is included in the range of 1200 to 1800 (pixels), 1900 (pixels) is set as the second threshold value.

  The data regarding the dark area is data specified by a dark part specifying unit 82b described later. Further, the data relating to the dark area is data to be compared with the above-described second threshold (see FIG. 9).

(C) Light / dark peak value related information storage area The light / dark peak value related information storage area 81c stores data related to the reference light / dark peak value and data related to the target light / dark peak value.

  The light / dark peak value refers to the light / dark value possessed by the largest number of pixels among all the pixels constituting the X-ray image. In other words, for the pixels constituting the X-ray image, when the number of pixels having each gray value is counted, the gray value having the largest number of pixels (see FIG. 10).

  The reference light / dark peak value is a light / dark peak value of an X-ray image of a positive quantity product. For the reference light and shade peak value, an upper limit value and a lower limit value are set as the reference light and shade peak width. The reference light and shade peak value is set by the user based on the light and shade peak values of the X-ray images related to the plurality of products G that have been determined to be positive products in the past. For example, when the light and shade peak values of a plurality of products G that have been determined to be positive products in the past are 110 to 130, 120 ± 10 is set as the reference light and shade peak value (reference light and shade peak width).

  The target grayscale value is the grayscale peak value of the X-ray image of the product G to be inspected. The target light / dark peak value is specified by the light / dark peak value specifying unit 82d described later.

(D) Boundary threshold storage area The boundary threshold storage area 81d stores a boundary threshold (third threshold) used by a boundary determination unit 82f described later. The boundary threshold value is a threshold value for specifying a light / dark boundary (boundary) in an X-ray image. The boundary is constituted by a plurality of adjacent pixels having a predetermined gray value difference. The gray value difference is the difference between the gray value of an arbitrary pixel (specific pixel) among the pixels constituting the X-ray image and the gray value of a pixel adjacent to the specific pixel (adjacent pixel). That is, the boundary threshold value is a threshold value for determining whether or not the gray value difference between adjacent pixels (specific pixel and adjacent pixel) among all the pixels constituting the X-ray image is a predetermined gray value difference. In the present embodiment, the boundary threshold value is a negative number (for example, a value smaller than 0).

(E) Gap-related information storage area The gap-related information storage area 81e stores information related to the gap equivalent amount. Specifically, the gap related information storage area 81e stores a gap equivalent amount determination value and a gap equivalent amount determined by a gap equivalent amount determination unit 82g described later.

  The gap equivalent amount determination value is a threshold value for determining the suitability of the gap equivalent amount included in the X-ray image. The gap equivalent amount is the number of pixels included in a region (gap equivalent region) corresponding to the gap between the article 50 and the seasoning 52 in the X-ray image. The gap-corresponding region is a region surrounded by pixels having a predetermined gray value difference among all the pixels included in the X-ray image. In other words, the gap equivalent area is an area surrounded by a boundary.

  The gap equivalent amount determination value is also set by the user based on gap equivalent amounts of X-ray images related to a plurality of products G that have been determined to be positive-quantity products in the past. For example, when the gap equivalent amounts of a plurality of products G that have been determined to be positive products in the past are 950 to 1050, 1000 ± 50 is set as the gap equivalent amount determination value (gap equivalent amount determination value width). .

(F) Determination Result Storage Area The determination result storage area 81f stores results determined by a first determination unit 82c, a second determination unit 82e, and a third determination unit 82h described later. Specifically, the determination result regarding the suitability of the total area of the dark part is stored as the determination result by the first determination unit 82c. In addition, as a determination result by the second determination unit 82e, a determination result relating to the suitability of the target grayscale peak value is stored. In addition, as a determination result by the third determination unit 82h, a determination result regarding the suitability of the gap equivalent amount is stored.

(2-6-2) Control Unit The control unit 82 executes various programs stored in the storage unit 81, thereby causing the image generation unit 82a, the dark part specification unit 82b, the first determination unit 82c, and the density peak value specification. Functions as a part 82d, a second determination part 82e, a boundary determination part 82f, a gap equivalent amount determination part 82g, a third determination part 82h, and a comprehensive determination part 82i.

(A) Image Generation Unit The image generation unit 82a generates an X-ray image based on the amount of transmitted X-rays detected by the X-ray line sensor 22 (or the intensity of transmitted X-rays). Specifically, the image generation unit 82a acquires X-ray transmission signals output from the X-ray detection elements 22a of the X-ray line sensor 22 at fine time intervals. The image generation unit 82a generates an X-ray image of the product G based on the X-ray transmission signal output when the product G passes through the fan-shaped X-ray irradiation range X (see FIG. 3). The gray value of one pixel is determined by the X-ray transmission signal output by one X-ray detection element 22a. By obtaining an X-ray transmission signal for the entire product G, two-dimensional X-ray image data for the product G is generated. The image generation unit 82a generates an X-ray image by classifying the gray value corresponding to the X-ray transmission signal into, for example, 256 gradations. The brightness (shading value) of the X-ray image depends on the amount of X-ray transmission.

  The image generation unit 82a generates, for example, the X-ray images A to C illustrated in FIGS. Each of the X-ray images A to C is an X-ray image of the seasoning 52 and the plurality of articles 50 filled in the bag 60. FIG. 6 is an X-ray image (X-ray image A) of a product G (a right-quantity product) in which the ratio between the article 50 and the seasoning 52 is within a specified range. That is, an appropriate amount of seasoning 52 is applied to the article 50. On the other hand, FIGS. 7 and 8 are X-ray images of the product G in which the ratio of the article 50 and the seasoning 52 is outside the specified range. Specifically, the X-ray image B of FIG. 7 shows a product G (mixed product 1) in which the seasoning 52 exceeding the specified amount is included and the seasoning 52 is gathered in one place of the bag 60. Further, the X-ray image C in FIG. 8 shows a product G (mixed product 2) in which the seasoning 52 exceeding the specified amount is included and the seasoning 52 spreads inside the bag 60. The X-ray image generated by the image generation unit 82a is stored in the X-ray image storage area 81a.

(B) Dark Part Specifying Unit The dark part specifying unit 82b specifies the dark part of the X-ray image stored in the X-ray image storage area 81a based on the first threshold value stored in the dark part information storage area 81b. Specifically, the dark part specifying unit 82b specifies a dark part having a predetermined gray value among all the pixels constituting the X-ray image using the first threshold value. More specifically, the dark part specifying unit 82b compares the first threshold value with the gray value of each pixel constituting the X-ray image, determines whether the gray value of each pixel is equal to or lower than the first threshold value, The X-ray image is binarized.

  Furthermore, the dark part specifying part 82b counts the number of pixels in the dark part among all the pixels constituting the binarized X-ray image, and specifies the dark part area (total area) of the X-ray image. In the present embodiment, as shown in FIG. 9, the dark part areas of the X-ray images A to C are respectively identified as 1693, 4265, and 2432. The dark part specifying unit 82b stores the specified dark part area in the dark part information storage region 81b in association with the X-ray image.

(C) 1st determination part The 1st determination part 82c is based on the X-ray image memorize | stored in the X-ray image storage area 81a, and the 2nd threshold value memorize | stored in the dark part information storage area 81b. It is determined whether G is a positive quantity product. Specifically, the first determination unit 82c compares the total area of the dark part included in the X-ray image with the second threshold value, and the total area of the dark part included in the X-ray image is equal to or less than the second threshold value. If it is, it is determined that the product G to be inspected is a positive-quantity product.

  In the present embodiment, as described above, 1900 (pixels) is set as the second threshold value. Therefore, it is determined that the X-ray image A having the dark area (1693) having a threshold value of 1900 or less is a positive product.

(D) Light / dark peak value specifying part The light / dark peak value specifying part 82d specifies the light / dark peak value (target light / dark peak value) of the X-ray image of the product G to be inspected. That is, the light / dark peak value specifying unit 82d specifies the light / dark value of the largest number of pixels among all the pixels constituting the X-ray image. Specifically, the shading peak value specifying unit 82d counts the number of pixels for each shading value (gradation) having a predetermined width. The density peak value specifying unit 82d specifies the density value (gradation) having the largest number of pixels as the density peak value.

  FIG. 10 shows curves L1 to L3 indicating the number of shade values (gradation value distribution) for each gradation specified by the shade peak value specifying unit 82d, and the shade peak values of each X-ray image. A curve L1 indicates the gray value distribution of the X-ray image B, a curve L2 indicates the gray value distribution of the X-ray image A, and a curve L3 indicates the gray value distribution of the X-ray image C. Based on the curves L1 to L3 in FIG. 10, it can be seen that the X-ray image A includes the most pixels with the gray value 123, and the X-ray image B includes the most pixels with the gray value 91. It can be seen that the X-ray image C contains the largest number of pixels with a gray value of 135 (see FIG. 9). The shading peak value specifying unit 82d associates the X-ray image with the target shading peak value of the X-ray image, and stores it in the shading peak value related information storage area 81c.

(E) Second determination unit The second determination unit 82e determines whether or not the product G to be inspected is a positive-quantity product based on the reference light and dark peak value stored in the light and dark peak value related information storage area 81c. To do. Specifically, the second determination unit 82e compares the target light and dark peak value specified by the above-described light and dark peak value specifying unit 82d with the reference light and dark peak value, and the target light and dark peak value becomes the reference light and dark peak value (reference light and dark value). If it is included in the (peak width), it is determined that the product G is a positive product. Further, the second determination unit 82e compares the target light and dark peak value with the reference light and dark peak value, and if the target light and dark peak value deviates from the reference light and dark peak value (reference light and dark peak width), the product G is a defective product. Judge.

  In the present embodiment, as described above, 120 ± 10 is set as the reference light / dark peak value (reference light / dark peak width). Therefore, it is determined that the X-ray image A having a light and shade peak value between 110 and 130 is a positive quantity product (see FIG. 9).

(F) Boundary Determination Unit The boundary determination unit 82f determines a boundary included in the X-ray image of the product G based on the boundary threshold stored in the boundary threshold storage area 81d. As described above, the boundary is a color shading boundary in one X-ray image. The boundary is constituted by adjacent pixels having a predetermined gray value difference. The gray value difference is the difference between the gray value of an arbitrary pixel (specific pixel) among the pixels constituting the X-ray image and the gray value of a pixel adjacent to the specific pixel (adjacent pixel). The boundary determination unit 82f determines whether or not the gray value difference between a plurality of adjacent pixels (specific pixels and adjacent pixels) out of all the pixels constituting the X-ray image is less than the boundary threshold value. The boundary determination unit 82f determines that the specific pixel and the adjacent pixel constitute a boundary when the gray value difference between the plurality of adjacent pixels is lower than the boundary threshold. On the other hand, the boundary determination unit 82f determines that there is no boundary between the specific pixel and the adjacent pixel when the gray value difference between the adjacent pixels is equal to or greater than the boundary threshold value.

  In the present embodiment, the boundary determination unit 82f performs a filter process in order to specify the gray value difference between a plurality of adjacent pixels. The filter processing employed in the present embodiment will be described using the X-ray image of FIG. FIG. 11 is a schematic diagram in which an X-ray image is partially enlarged. For ease of explanation, FIG. 11 shows an X-ray image of product G that does not include seasoning 52. A hatched portion in FIG. 11 is a region indicating the article 50, and a region Ar1 surrounded by the diagonal line is a gap region. In FIG. 11, each of a large number of square regions P corresponds to one pixel. For example, the gray value of a pixel overlapping the article 50 is set to 100. That is, when even a slight shaded part is applied to the region P, the gray value of the pixel corresponding to the region P is set to 100. For example, the boundary determination unit 82f performs filter processing on the X-ray image using a filter coefficient fc as illustrated in FIG. Specifically, the product is obtained by multiplying the gray value of 9 pixels of 3 × 3 and the filter coefficient (numerical value in parentheses), and the sum of the products is obtained. The sum of products is set to the value of one pixel located at the center of 9 pixels of 3 × 3. In the filter processing, when the value of one pixel is obtained, the target pixels are shifted one row or one column at a time, and values for all the pixels are obtained.

  FIG. 13 shows the result of applying the filtering process to the main part of FIG. The numerical value described in each pixel in FIG. 13 is the gray value difference obtained by the filter processing. In FIG. 13, a pixel represented by “−” is a pixel in which the value obtained by the filtering process is a negative value. In the present embodiment, since the boundary threshold value is a value smaller than 0 (that is, a negative value), the pixel represented by “−” in FIG. 13 is a portion corresponding to the boundary. Further, in FIG. 13, the portion where the gray value difference is 0 is a portion where there is no color change in the X-ray image.

(G) Gap equivalent amount determination unit The gap equivalent amount determination unit 82g determines the gap equivalent amount included in the X-ray image based on the boundary determined by the boundary determination unit 82f. As described above, the gap equivalent amount is the number of pixels having a gray value difference among pixels included in a region (gap equivalent region) corresponding to the gap between the article 50 and the seasoning 52 in the X-ray image. In other words, the gap equivalent region is a portion surrounded by the boundary determined by the boundary determination unit 82f, and the gap equivalent amount is the number of pixels obtained by excluding pixels having no gray value difference from the portion surrounded by the boundary. is there.

  Specifically, the gap equivalent amount determination unit 82g determines the gap equivalent region based on the boundary included in the X-ray image determined by the boundary determination unit 82f. Further, the gap equivalent amount determination unit 82g determines the gap equivalent amount by counting the number of pixels obtained by subtracting pixels with a gray value difference of 0 from all the pixels included in the gap equivalent region. For example, in the X-ray image of FIG. 13, the number of pixels included in the region surrounded by the boundary (gap equivalent region) is 23. Of these, there are four pixels with a gray value difference of zero. Therefore, in the X-ray image shown in FIG. 13, the gap equivalent amount determined by the gap equivalent amount determination unit 82g is 19 (pixels). In the present embodiment, as shown in FIG. 9, the gap equivalent amounts of the X-ray images A to C are determined to be 1026, 751, and 1095, respectively. The gap equivalent amount determination unit 82g associates the determined gap equivalent amount with the X-ray image and stores them in the gap related information storage area 81e.

(H) Third Determination Unit The third determination unit 82h determines whether or not the product G to be inspected is a positive-quantity product based on the clearance equivalent amount determination value stored in the clearance related information storage area 81e. Specifically, the third determination unit 82h compares the gap equivalent amount of the X-ray image determined by the gap equivalent amount determination unit 82g with the gap equivalent amount determination value, and the gap equivalent amount of the X-ray image is determined. It is determined whether or not the value is included in the gap equivalent amount determination value.

  In the present embodiment, as described above, 1000 ± 50 is set as the gap equivalent amount determination value (gap equivalent amount determination value width). Therefore, it is determined that the X-ray image A having the gap equivalent amount between 950 and 1050 is a positive product (see FIG. 9).

(I) Comprehensive determination unit The comprehensive determination unit 82i comprehensively determines whether or not the product G to be inspected is a positive-quantity product based on the determination result stored in the determination result storage area. The comprehensive determination unit 82i can execute at least one of the first comprehensive determination, the second comprehensive determination, and the third comprehensive determination according to the setting by the user.

  In the first comprehensive determination, a final determination is made as to whether or not the product G is a right-quantity product based on the suitability of the total area of the dark part determined by the first determination unit 82c.

  In the second comprehensive determination, whether the product G is a right-quantity product based on the suitability of the total area of the dark part determined by the first determination unit 82c and the suitability of the target density peak value determined by the second determination unit 82e. A final decision is made whether or not.

  Further, in the third comprehensive determination, in addition to the suitability of the total area of the dark portion determined by the first determination unit 82c and the suitability of the target grayscale value determined by the second determination unit 82e, the third determination unit 82h determines. Based on the suitability of the gap equivalent amount, a final determination is made as to whether or not the product G is a correct product. That is, in the third comprehensive determination, the product G that is determined to be a correct product in all the determination results stored in the determination result storage area is comprehensively determined as a correct product.

(3) Processing related to determination of seasoning amount Next, processing related to determination of the seasoning amount by the X-ray inspection apparatus 10 according to the present embodiment will be specifically described with reference to FIGS.

(3-1) X-ray Image Generation Processing First, the X-ray image generation processing by the image generation unit 82a will be described with reference to FIG. In step S <b> 1, it is determined whether the product G has come on the X-ray line sensor 22. When the product G comes on the X-ray line sensor 22, the voltage of the X-ray transmission signal output from the X-ray detection element 22a changes. Therefore, in step S1, specifically, it is determined whether or not the voltage of the X-ray transmission signal is equal to or lower than a predetermined threshold value. In step S1, when the voltage of the X-ray transmission signal becomes equal to or lower than a predetermined threshold value, it is determined that the product G has been on the X-ray line sensor 22, and the process proceeds to step S2. On the other hand, if the voltage of the X-ray transmission signal does not fall below the predetermined threshold in step S <b> 1, the process waits until the product G comes on the X-ray line sensor 22.

  In step S2, an X-ray transmission signal output from the X-ray line sensor 22 is acquired by the image generation unit 82a, and an X-ray image of the product G is generated based on the X-ray transmission signal (FIGS. 6 to 8). reference). Next, the process proceeds to step S3.

  In step S <b> 3, it is determined whether or not the product G has passed over the X-ray line sensor 22. That is, similarly to the above, it is determined whether or not the voltage of the X-ray transmission signal exceeds a predetermined threshold value. In step S3, an X-ray image is continuously generated until the product G passes over the X-ray line sensor 22, and when it is determined that the product G passes over the X-ray line sensor 22, the process proceeds to step S4.

  In step S4, the X-ray image of the product G is stored in the X-ray image storage area 81a.

(3-2) Determination of Dark Area The dark area determination process will be described with reference to FIG. In step S11, the X-ray image stored in the X-ray image storage area 81a is read out. At this time, the most recently stored X-ray image is read out. In other words, an X-ray image of the product G to be inspected is read out.

  Next, in Step S12, the dark part of the X-ray image is specified by the dark part specifying part 82b. Specifically, the dark part specifying part 82b compares the first threshold value stored in the dark part information storage area 81b with the gray value of each pixel constituting the X-ray image, and forms each X-ray image. The X-ray image is binarized based on whether the gray value of the pixel is equal to or less than the first threshold value.

  Thereafter, in step S13, the dark portion specifying unit 82b counts the number of dark portions of all the pixels constituting the binarized X-ray image, and specifies the dark portion area of the X-ray image (FIG. 9). reference). Information regarding the identified dark area is stored in the dark area information storage area 81b. Thereafter, the process proceeds to step S14.

  In step S14, whether or not the dark area is appropriate is determined by the first determination unit 82c. Specifically, the dark area of the X-ray image is compared with the second threshold value, and the suitability of the dark area is determined. More specifically, when the dark area is equal to or smaller than the second threshold, it is determined that the amount of seasoning 52 included in the product G is a specified amount, and when the dark area exceeds the second threshold, It is determined that the amount of seasoning 52 is not the prescribed amount. For example, by setting 1900 (pixels) as the second threshold value, it is possible to determine whether or not the product G corresponding to the X-ray images of FIGS. In other words, it is determined that the product G represented by the X-ray image in FIG.

  Thereafter, the process proceeds to step S15, and in step S15, the determination result by the first determination unit 82c is stored in the determination result storage area 81f.

(3-3) Determination of Light / Light Peak Value Next, the light / dark peak value determination process will be described with reference to FIG. First, in step S21, the X-ray image stored in the X-ray image storage area 81a is read. At this time, the most recently stored X-ray image is read out. In other words, an X-ray image of the product G to be inspected is read out.

  Next, the process proceeds to step S22, in which the shading peak value specifying unit 82d specifies the shading peak value of the X-ray image. Specifically, it is determined which of all the pixels constituting the X-ray image of the product G has a gray value.

  Thereafter, the process proceeds to step S23, and the second determination unit 82e determines whether the target light / dark peak value is appropriate. Specifically, the second determination unit 82e compares the reference light and dark peak value stored in the light and dark peak value related information storage area 81c with the target light and dark peak value, and the target light and dark peak value becomes the reference light and dark peak value ( It is determined whether or not the value is included in the (reference grayscale peak width). In the present embodiment, for example, by setting 120 ± 10 (lower limit value 110, upper limit value 130) as the reference shading peak value, the quality of the product corresponding to the X-ray images A to C is determined. Can do. In other words, it is determined that the product G represented by the X-ray image A is a positive product.

  In step S23, if the appropriateness of the target grayscale peak value is determined by the second determination unit 82e, the process proceeds to step S24. In step S24, the determination result is stored in the determination result storage area 81f.

(3-4) Determination of gap equivalent amount Next, a gap equivalent amount determination process will be described with reference to FIG. First, in step S31, the X-ray image stored in the X-ray image storage area 81a is read. At this time, the most recently stored X-ray image is read out. In other words, an X-ray image of the product G to be inspected is read out.

  Next, in step S32, the boundary determination unit 82f determines the boundary included in the X-ray image. Specifically, by executing the filtering process, the gray value difference with the adjacent pixel is determined for each pixel constituting the X-ray image. The boundary determination unit 82f determines that a pixel having a gray value difference lower than the boundary threshold is a boundary in the X-ray image.

  Next, in step S33, a gap equivalent region in the X-ray image is specified by the gap equivalent amount determination unit 82g. Specifically, the gap-equivalent amount determination unit 82g specifies an area surrounded by the boundary in the X-ray image as the gap-equivalent area. Further, the gap-equivalent amount determination unit 82g subtracts the number of pixels having no grayscale value difference from the total number of pixels included in the gap-equivalent area. The gap equivalent amount determination unit 82g determines the gap equivalent amount by counting the number of pixels having a gray value difference other than 0 in the gap equivalent region. The gap equivalent amount determination unit 82g associates the determined gap equivalent amount with the X-ray image and stores them in the gap related information storage area 81e.

  Thereafter, the process proceeds to step S34, and the third determination unit 82h determines whether the gap equivalent amount is appropriate. Specifically, the third determination unit 82h compares the gap equivalent amount determination value stored in the gap related information storage area 81e with the gap equivalent amount stored in the gap related information storage area 81e, and the gap equivalent amount. Is a value included in the gap equivalent amount determination value (gap equivalent amount width). In the present embodiment, for example, by setting 1100 ± 100 (lower limit value 900, upper limit value 1200) as the gap equivalent amount determination value, the quality of the product represented by the X-ray images A to C is determined. be able to. In other words, it is determined that the product G represented by the X-ray image A is a positive product.

  If it is determined in step S34 that the gap determination amount is appropriate by the third determination unit 82h, the process proceeds to step S35. In step S35, the determination result is stored in the determination result storage area 81f.

(3-5) Comprehensive Determination Process Next, the comprehensive determination process will be described with reference to FIG. First, in step S41, the comprehensive determination unit 82i determines whether or not the comprehensive determination type set by the user is the first comprehensive determination. In step S41, if the type setting is the first comprehensive determination, the process proceeds to step S42. If the type setting is not the first comprehensive determination, the process proceeds to step S43.

  In step S42, the comprehensive determination unit 82i performs the first comprehensive determination. Specifically, the comprehensive determination unit 82i performs comprehensive determination based on the first determination result. In other words, the comprehensive determination unit 82i makes a final determination as to whether or not the product G is a right-quantity product based on the suitability of the total area of the dark part stored in the determination result storage area 81f.

  On the other hand, in step S43, the comprehensive determination unit 82i determines whether the comprehensive determination type set by the user is the second comprehensive determination. In step S43, if the type setting is the second comprehensive determination, the process proceeds to step S44. If the type setting is not the second comprehensive determination, the process proceeds to step S45.

  In step S44, the comprehensive determination unit 82i performs the second comprehensive determination. Specifically, the comprehensive determination unit 82i performs a comprehensive determination based on both the first determination result and the second determination result. In other words, the overall determination unit 82i finally determines whether or not the product G is a right-quantity product based on the determination regarding the suitability of the total area of the dark part stored in the determination result storage area 81f and the determination on the suitability of the target gray peak value. I do. The overall determination unit 82i finally determines that the product is a right product only for the product G determined to be a right product in both determinations. On the other hand, if at least one of the products is not determined to be a right-quantity product, the overall determination unit 82i finally determines the product G to be a defective product (mixed product).

  In step S45, a third comprehensive determination is performed by the comprehensive determination unit 82i. Specifically, the comprehensive determination unit 82i performs comprehensive determination based on all of the first determination result, the second determination result, and the third determination result. In other words, the overall determination unit 82i determines whether the product G is based on the determination regarding the appropriateness of the total area of the dark part stored in the determination result storage area 81f, the determination regarding the appropriateness of the target shade peak value, and the determination regarding the appropriateness of the gap equivalent amount. A final decision is made as to whether the product is a regular product. The comprehensive determination unit 82i finally determines that the product is a right product only for the product G that is determined as a right product by all three determination results. On the other hand, if at least one of the products is not determined to be a correct product, the overall determination unit 82i finally determines the product G to be a defective product (mixed product).

(4) Features (4-1)
In the above embodiment, the ratio between the article 50 and the seasoning 52 included in the product G to be inspected is determined based on the dark area of the X-ray image (first comprehensive determination). The product G to be inspected is a product G in which a bag 60 is filled with an article 50 such as potato chips or pretzel and a seasoning 52. When the package includes an article 50 fried in oil, such as potato chips or pretzel, and a seasoning 52 that is applied to the article 50, the seasoning 52 is measured by the oil content of the article 50 when the package is weighed. Easy to stick to the vessel. As a result, the seasoning 52 fixed to the measuring instrument may be collected and filled into the bag 60. In such a case, the ratio of the article 50 and the seasoning 52 filled in the bag 60 is not appropriate. That is, even when the total amount of the product G is within the specified range, the ratio of the seasoning 52 included in the product G is high, and the article 50 is not filled with an appropriate amount.

  Therefore, the X-ray inspection apparatus 10 according to the embodiment inspects the ratio between the article 50 and the seasoning 52 included in the product G to be inspected based on the dark area of the X-ray image. The X-ray inspection apparatus 10 generates an X-ray image (see FIGS. 6 to 8) based on the X-ray dose that has passed through the product G. Based on the X-ray image, the X-ray inspection apparatus 10 generates an article 50 and a seasoning 52 included in the product G. It is determined whether the ratio is within a specified range. An article 50 in which potato or flour is baked and hardened (a block) is mainly composed of carbohydrates. The article 50 also contains a lot of oxygen and hydrogen. On the other hand, the seasoning 52 contains a large amount of chlorine (specifically, salt (NaCl)). In general, the larger the atomic number, the higher the amount of X-ray absorption per unit volume. In other words, the larger the atomic number, the lower the X-ray transmittance per unit volume. Therefore, the seasoning 52 containing salt absorbs X-rays from the article 50 containing oxygen and hydrogen and hardly transmits X-rays. That is, as a result of the reduced amount of X-ray transmission, the dark part of the X-ray image increases.

  In the above-described embodiment, using the above principle, the X-ray inspection apparatus 10 identifies a dark part having a predetermined gray value in the X-ray image, and determines whether the product G is appropriate based on the dark part area. That is, after the lump of seasoning 52 is filled in the bag 60 and expands inside the bag 60, the X-ray image has a large portion (dark part) where the transmitted X-ray dose is small. That is, it can be determined that a large amount of seasoning 52 is included in an X-ray image having a dark area larger than a predetermined threshold (second threshold). Thereby, the product G including the seasoning 52 exceeding the specified amount can be specified.

(4-2)
In the embodiment described above, the ratio between the article 50 and the seasoning 52 included in the product G to be inspected is determined based on the density peak value of the X-ray image in addition to the dark area of the X-ray image (second comprehensive Judgment). When the ratio of the article 50 and the seasoning 52 in the bag 60 is determined based on the determination based on the dark area of the X-ray image, for example, when the seasoning 52 is gathered in one place inside the bag 60, only the dark area is Based on this, the determination may be wrong.

  However, in the X-ray inspection apparatus according to the above-described embodiment, the determination is further performed based on the shading peak value of the X-ray image. The shading peak value of the X-ray image is a value indicating the shading value distribution of each pixel constituting the X-ray image. In the X-ray inspection apparatus, a reference grayscale value (reference grayscale peak width) is set as a threshold value, and it is determined whether the X-ray image is a correct product by determining whether or not the grayscale peak value of the X-ray image is included in the standard grayscale peak width. It is determined whether or not. Specifically, when the product G to be inspected is the mixed product 1 (see FIG. 7) in which the seasoning 52 is gathered at one place of the bag 60, the seasoning 52 is gathered in the X-ray image. The area of the part increases. As a result, the shading peak value of the X-ray image may be lower than the shading peak value of the positive quantity product. On the other hand, when the product G to be inspected is the mixed product 2 (FIG. 8) in which the seasoning 52 is expanded inside the bag 60, the X-ray is coupled with the fact that the mixed product 2 contains a small number of articles 50. The area of the bright part in the image may be large. Therefore, the light and shade peak value of the X-ray image is higher than the light and dark product. As described above, when the target light and shade peak value is smaller than the reference light and shade peak value, the bag 60 is filled with the seasoning 52 exceeding the specified amount, and the seasoning 52 is gathered inside the bag 60. I understand. In addition, when the target light and shade peak value is larger than the reference light and shade peak value, it can be seen that the seasoning 52 exceeding the specified amount is filled and the seasoning 52 spreads thinly in the bag 60 as a whole. .

(4-3)
In the above-described embodiment, the ratio between the article 50 and the seasoning 52 included in the product G to be inspected is determined based on the dark area and density peak value of the X-ray image, and the gap area of the X-ray image (first). 3 comprehensive judgment).

  When the amount of seasoning 52 is an appropriate amount, the amount of seasoning 52 exceeds the appropriate amount even if there is a predetermined gap between the items 50 and 50, and the seasoning 52 occupying the product G When the amount increases, the gap between the article 50 and the article 50 (gap) is easily filled with the seasoning 52. That is, the amount of the gap formed between the article 50 and the article 50 tends to decrease. As a result, the amount of X-ray transmission decreases as compared with a positive-quantity product, and there is a tendency for the change in shading in the dark part of the X-ray image to be reduced. Therefore, in the X-ray inspection apparatus according to the embodiment, the gap area of the X-ray image is further used as an index for determining the ratio between the article 50 and the seasoning 52. Thereby, it can be seen that the amount of seasoning 52 contained in the product G is not the prescribed amount.

  Even when a large amount of seasoning 52 is filled in the bag 60, when the seasoning 52 does not spread inside the bag 60 and is gathered in one place, or when the seasoning 52 is hardened, the seasoning 52 becomes an article 50. And filling the gap between the article 50 are rare. Therefore, the amount of X-ray transmission does not decrease compared to a positive-quantity product. However, in the above-described embodiment, the final comprehensive determination is performed in consideration of the dark area and the density peak value of the X-ray image in addition to the gap area. As a result, when the seasonings 52 are gathered in one place inside the bag 60 or when the articles 50 overlap each other, the seasoning 52 mixed in a large amount inside the bag 60 spreads, and the articles 50 are scattered on the top. Even in such a case, the ratio between the article 50 and the seasoning 52 can be appropriately determined. That is, the accuracy of inspection (determination) by the X-ray inspection apparatus 10 can be improved.

(5) Modification (5-1) Modification A
In the above embodiment, as the second comprehensive determination, the positive-quantity product is determined based on the first determination result and the second determination result. However, the first determination result and the third determination result may be used as the second comprehensive determination.

(5-2) Modification B
Further, in the above embodiment, when determining a correct product based on two or more determination results, not only a method of using each determination result as it is, but also a comprehensive determination by weighting each determination result. You may go. For example, when the determination results of the first determination unit 82c and the second determination unit 82e are combined, the determination results of the first determination unit 82c and the second determination unit 82e may be “correct products” or “non-correct products”. ”And“ There is a high possibility that the product is not a regular product ”. Then, the determination result of the first determination unit 82c is regarded as important, and points “0.6”, “0.3”, “0” are assigned to each stage of the first determination unit 82c, and the first determination unit 82c. Are assigned points “0.4”, “0.2”, and “0.1”. For example, the overall determination unit 82i may determine that the product is a positive product if the total of the determination results is equal to or greater than a predetermined value (for example, 0.6 or greater). When the determination result is divided into a plurality of stages, a plurality of threshold values are provided so as to indicate the boundaries of the respective stages.

(5-3) Modification C
In the above embodiment, potato chips and pretzel are exemplified as the article 50. However, the article 50 may be other than the seasoning (powder) 52, as long as it is a sufficiently large lump. . Further, the article 50 and the powdered material 52 need only have different X-ray transmittances and do not need to be composed of different elements.

(5-4) Modification D
In the above embodiment, the X-ray detection elements 22a are horizontally arranged in a straight line in a direction orthogonal to the conveying direction by the conveyor unit 12. However, the arrangement of the X-ray detection elements 22a is not limited to the above embodiment. Further, instead of moving the product G by the conveyor unit 12, the X-ray irradiator 21 and the X-ray line sensor 22 may be moved.

(5-5) Modification E
In the above embodiment, the image data stored in the X-ray image storage area 81a may be any data as long as it can form an X-ray image of the product G. For example, in addition to the gray value of each pixel constituting the X-ray image, it may be a value indicating the amount of X-ray transmission detected by the X-ray detection element 22a. The image generation unit 82a may perform image processing on the X-ray image. For example, image processing such as smoothing and sharpness may be performed.

(5-6) Modification F
In the above embodiment, the case where the dark part specifying unit 82b binarizes the X-ray image using the first threshold value has been described. However, the dark part may be further divided and weighted in each section. For example, the dark part is divided into two, “dark pixels” and “relatively bright pixels”, and “1” and “0.5” are assigned to each. When the dark part area is specified by the dark part specifying part 82b, dark pixels may be counted as 1, and two relatively bright pixels may be counted as 1. In this case, two types of first threshold values are required to classify the pixels into three types: “dark pixels”, “relatively bright pixels”, and “bright pixels”.

(5-7) Modification G
In the above embodiment, the boundary determination unit 82f determines the light / dark boundary of the X-ray image. Further, the area surrounded by the boundary is defined as a gap equivalent area, and the gap equivalent amount is determined by subtracting the number of pixels having no grayscale value difference from all the pixels included in the gap equivalent area. Here, as the boundary length increases, the number of pixels contained inside the boundary also increases, and the resulting gap equivalent amount also increases. Therefore, the size of the gap equivalent amount is determined by the size of the boundary length. Also good. This also makes it possible to determine that a large amount of seasoning 52 is mixed in the bag 60 as in the above embodiment.

(5-8) Modification H
In the above embodiment, the opening 11a of the shield box 11 is blocked by the shielding nolen. Here, a buffer plate 11c may be further provided in the opening 11a. The buffer plate 11c is a SUS plate-like member. For example, as illustrated in FIG. 19, the buffer plate 11 c is disposed inside the shield box 11 with respect to the shielding noll 11 b. The buffer plate 11c is attached so as to extend from the upper side to the lower side in the same manner as the shielding noll 11b. Here, the buffer plate 11c preferably has a predetermined length. The predetermined length is a length shorter than the shielding noll 11b and does not contact the belt of the conveyor unit 12. Specifically, when the boxed article 50 is an object to be inspected, the length of the buffer plate 11c is such that the tip of the buffer plate 11c comes to a position below the upper side of the box conveyed by the conveyor unit 12. Is determined.

  Conventionally, when a boxed article is an article to be inspected, the corner of the box is in contact with the shielding noll 11b when the article 50 that has been inspected comes out of the shield box 11. The shield noren 11b was worn in a short period of time due to the contact. However, as shown in FIG. 19, in the opening 11a, a buffer plate 11c is provided on the inner side of the shielding noll 11b to prevent direct contact between the corner of the box and the shielding noll 11b, thereby reducing the wear of the shielding noren. Can be made.

(5-9) Modification I
As shown in FIG. 20, the X-ray inspection apparatus 10 according to the embodiment includes a guide portion 22 b that guides the X-rays emitted from the X-ray irradiator 21 to the X-ray line sensor 22. The guide portion 22b is a rectangular member that extends in the belt width direction. A slit is formed in the guide portion 22b along the longitudinal direction. X-rays transmitted through the article are detected by the X-ray line sensor 22 through the slit. In addition, the X-ray inspection apparatus 10 according to the above embodiment includes a transmission window 22c that transmits X-rays below the guiding portion 22b and above the X-ray line sensor 22. The transmission window 22c is made of a light element and is non-metallic. The transmission window 22 c has a function of adjusting the contrast of X-rays that have passed through the article 50.

  Here, the X-ray inspection apparatus 10 may have shielding plates 22d and 22d along the longitudinal direction of the guiding portion 22b on the upstream side and the downstream side of the guiding portion 22b. The transmission window 22 transmits X-rays but partially reflects them. X-rays partially reflected by the transmission window 22 are scattered around (see FIG. 21). Therefore, in the absence of the shielding plates 22d and 22d, scattered X-rays may leak out from the outside of the guiding portion 22b and the gap between the conveyor units 12. However, by providing the shielding members 22d and 22d, it is possible to prevent the light reflected by the transmission window 22c from leaking from the outside of the guiding portion 22b and the gap of the conveyor unit 12 as shown in FIG.

10 X-ray inspection equipment 21 X-ray irradiator (X-ray irradiation unit)
22 X-ray line sensor (X-ray detector)
30 Liquid crystal monitor 80 Control device 81 Storage unit 81d Boundary threshold storage area (third threshold storage area)
81e Gap-related information storage area 82 Control part 81a Image generation part 82b Dark part specification part 82c First determination part 82d Light / dark peak value specification part 82e Second determination part 82g Gap equivalent amount determination part 82h Third determination part

JP 2004-93463 A

Claims (5)

X for determining a right-quantity product in which an appropriate amount of an article having a first X-ray transmittance and a granular material having a second X-ray transmittance different from the first X-ray transmittance are packaged A line inspection device,
An X-ray irradiation unit that irradiates the inspection object including the article and the granular material with X-rays;
An X-ray detector for detecting X-rays transmitted through the inspection object;
An image generator that generates an X-ray image according to the intensity of transmitted X-rays detected by the X-ray detector;
A dark part specifying unit that specifies a dark part having a predetermined gray value in the X-ray image based on a first threshold;
A first determination unit that determines the positive-quantity product based on a total area of the dark part included in the X-ray image and a second threshold;
An X-ray inspection apparatus comprising: A first storage area for storing a reference light and dark peak value that is a light and dark peak value of an X-ray image of the positive-quantity product;
A light and shade peak value specifying unit for specifying a target light and shade peak value that is a peak of the light and shade value of the X-ray image generated by the image generating unit;
A second determination unit for determining the right-quantity product based on the reference light and shade peak value and the target light and shade peak value;
Further comprising
The X-ray inspection apparatus according to claim 1. The reference light and shade peak value is a range of a reference light and shade peak value determined based on an X-ray image relating to a plurality of the positive-quantity products,
The second determination unit determines whether or not the target light and shade peak value is included in the range;
The X-ray inspection apparatus according to claim 2. A gap for determining a gap equivalent amount of the article determined based on a gray value difference that is a difference between a gray value of a first pixel constituting the X-ray image and a gray value of an adjacent pixel adjacent to the first pixel. A substantial amount determination unit;
A third determination unit that determines the right-quantity product based on the gap equivalent amount included in the X-ray image;
The X-ray inspection apparatus according to claim 2 or 3. A third threshold storage area for storing a third threshold that is a threshold relating to the gray value difference;
A gap-related information storage area for storing a gap equivalent amount determination value for determining whether or not the gap equivalent amount included in the X-ray image is appropriate.
The gap equivalent amount determination unit determines a total amount of the gap equivalent amount included in the X-ray image based on the third threshold value,
The third determination unit determines whether or not a total amount of the gap equivalent amount is included in a predetermined range based on the gap equivalent amount determination value.
The X-ray inspection apparatus according to claim 4.

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