JP3682587B2 - X-ray foreign substance inspection apparatus and determination parameter setting apparatus for X-ray foreign substance inspection apparatus - Google Patents

Description

  The present invention relates to an X-ray foreign substance inspection apparatus for determining whether or not a foreign substance is present in an X-ray fluoroscopic image of an inspection object such as food, and this type of X-ray foreign substance inspection. The present invention relates to a determination parameter setting device capable of arbitrarily setting a determination parameter for a device at a place.

  As a device for inspecting whether or not foreign matter is mixed in the inspection object, the inside of the inspection object is seen through using X-rays, and the fluoroscopic image is image-processed to thereby detect the foreign matter in the inspection object. An apparatus for inspecting presence / absence of existence is known (for example, see Patent Document 1).

  This type of X-ray foreign substance inspection apparatus is schematically shown in FIG. In FIG. 6, (A) is a diagram showing a schematic diagram showing a mechanical configuration viewed from the side of the conveyance direction of the inspection object W and a block diagram showing an electrical configuration, and (B) is a diagram. It is a schematic diagram showing the mechanical structure seen from the right side surface. The X-ray source 61 and the X-ray detector 62 are arranged to face each other, and a transport device 63 for transporting the inspection object W is disposed between them.

  The X-ray source 61 outputs fan beam-shaped X-rays, and the X-ray detector 62 is a one-dimensional detector in which a plurality of elements are arranged in the fan beam-shaped X-ray spreading direction. The fan beam is conveyed in a direction perpendicular to the X-ray. The inspection object W is detected by the pair of the photoelectric sensor 64a and the reflection plate 64b to arrive at the position where the X-ray source 61 and the X-ray detector 62 are arranged. The X-ray fluoroscopic image of the inspection object W is stored in the image processing device 65 by taking the output of the X-ray detector 62 into the image processing device 65 every moment until the passage between the line detectors 62 is completed. Will be captured.

  The image processing device 65 determines whether or not the foreign matter S is mixed by image processing the X-ray fluoroscopic image of the inspection object W, and the determination result (OK / NG) is the downstream side of the transport device 63. In the case of NG, the inspection object W is excluded.

  The image processing device 65 is connected to a display unit for displaying an X-ray fluoroscopic image of the inspection object W and an input unit for setting parameters for determining the presence or absence of foreign matter. In this example, these functions are provided. A touch panel 65a with a monitor is also connected.

  Here, the dose distribution of X-rays transmitted through the inspection object W is not constant depending on the thickness of the inspection object W, the contents, and the like, and the determination of the presence or absence of foreign matter by the image processing apparatus 65 is usually one threshold. Using a value, it is not possible to adopt a simple method for determining that there is a foreign substance because there is a site where the X-ray dose is below a certain level.

  Therefore, a plurality of determination parameters are generally set for the determination of the presence / absence of a foreign object by the image processing apparatus 65. For example, FIG. 7 will be described using a graph showing an example of the relationship between each element (position) of a one-dimensional X-ray detector and its output (X-ray dose). Compared with two threshold values Th1 and Th2. The distance Lc is used as a determination parameter. Of these, the threshold value Th1 is used to determine that there is a foreign object if there is a portion below this level, and the threshold value Th2 is the element output within the comparison distance Lc with respect to each element output. Is a parameter for determining the presence of foreign matter when the difference is greater than the threshold value Th2.

In order to set the values of the determination parameters Th1, Th2, Lc and the like as described above, conventionally, an inspection object and a foreign object to be detected are prepared, and a foreign object mixed sample which is an inspection object mixed with the foreign object is prepared. Thus, an optimal combination of parameters has been set using the X-ray transmission information. At this time, there are generally a plurality of types of foreign substances to be detected. Therefore, a plurality of types of foreign substances are prepared, and a foreign substance mixed sample is prepared by mixing each foreign substance into the inspection object one by one. It is necessary to set a parameter group for determining the presence of foreign matter for a foreign matter mixed sample.
JP 2001-281173 A

  By the way, in the preparation of a foreign substance-contaminated sample when setting the conventional determination parameters as described above, although it is actually easy to obtain an inspection object that is normal, that is, without foreign substances, the inspection is performed. It is often difficult to obtain multiple types of foreign matter immediately, so it takes a relatively long time to create a foreign-contaminated sample and set parameters, during which time the operation of the equipment must be stopped at the production site. There was a problem that had to be done.

  In addition, for articles whose properties change over time, such as ice cream, it is practically impossible to set parameters by preparing a sample containing foreign matter in advance as described above. In many cases, such an apparatus for inspecting foreign matter in an article must be adjusted and verified after being introduced into the actual line, which causes trouble after introduction due to operation under insufficient verification. There was also.

  The present invention has been made in view of such circumstances, and it is possible to optimally set determination parameters without actually creating a foreign matter mixed sample, and for articles whose physical properties change over time. In addition, the X-ray foreign substance inspection device that can be easily adjusted and verified in advance and the determination parameters for the X-ray foreign substance inspection device are optimized at any place without using the actual X-ray foreign substance inspection device. The problem is to provide a simulation device that can be set.

  In order to achieve the above object, the X-ray foreign matter inspection apparatus of the present invention irradiates X-rays while conveying an inspection object by a conveying means between an X-ray source and an X-ray detector arranged to face each other. Image processing means for determining the presence / absence of a foreign substance in the inspection object by using image processing using an X-ray fluoroscopic image of the inspection object obtained by using a determination parameter set in advance by a setting means In the X-ray foreign substance inspection apparatus, the storage means for storing a plurality of types of foreign substance patterns and the X-ray fluoroscopic image of the inspection object free of foreign substances imaged by the X-ray detector are stored in the storage means. An image composition means for selectively composing any of a plurality of types of foreign matter patterns is provided, and the determination parameter can be set by the setting means using the synthesized image. Characterized (claim 1).

  In the determination parameter setting apparatus for the X-ray foreign substance inspection apparatus of the present invention, the presence or absence of foreign substances in the inspection object is set in advance by image processing using an X-ray fluoroscopic image of the inspection object. An apparatus for setting a foreign matter determination parameter used in image processing means in an X-ray foreign matter inspection apparatus to be determined using a determination parameter, and has the same function as that used in the X-ray foreign matter inspection apparatus Image processing means, storage means for storing a plurality of foreign object patterns, data capturing means for loading an X-ray fluoroscopic image of an inspection object without foreign objects imaged by an X-ray foreign object inspection apparatus, and the acquired inspection object Image synthesizing means for selectively synthesizing an X-ray fluoroscopic image and an arbitrary one of a plurality of types of foreign substance patterns stored in the storage means, and using the synthesized image Te, characterized by that it comprises a setting means for setting a determination parameters used by the image processing means (claim 2).

  According to the X-ray foreign substance inspection apparatus of the present invention, a plurality of types of foreign substance patterns are stored in the storage means, and an X-ray fluoroscope of an inspection object in which any foreign substance pattern is imaged by an X-ray detector is absent. Since it is possible to set a parameter for determination by the image processing means using the synthesized image after being synthesized with the image, the actual inspection object is necessary only when imaging with the X-ray detector, and The determination parameter can be set without preparing an actual foreign material sample. As a result, a series of time required for setting the determination parameters can be greatly shortened as compared with the prior art, and at the same time, an operation for creating a foreign matter mixed sample is not required.

  In addition, for articles whose physical properties change over time, all that is needed is to take a fluoroscopic image, so parameters can be set just like normal articles, and prior adjustments can be made. -Verification can be performed easily and it becomes easy to introduce this kind of X-ray foreign material inspection apparatus also to such articles.

  On the other hand, according to the determination parameter setting apparatus for the X-ray foreign substance inspection apparatus of the present invention, for example, an X-ray fluoroscope imaged of an inspection object without foreign objects imaged by an X-ray detector of an actual X-ray foreign substance inspection apparatus By loading the image, the foreign matter pattern was synthesized with the X-ray fluoroscopic image of the object to be inspected at any location away from the X-ray foreign matter inspection apparatus without preparing an actual foreign matter sample in the same manner as described above. Using the image, it is possible to set determination parameters for the image processing means. For example, for the next inspection object without stopping the production line in which the actual X-ray foreign substance inspection apparatus is incorporated. Determination parameters can be set, and production efficiency can be improved.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram of an embodiment of the present invention, and is a diagram illustrating a schematic diagram representing a mechanical configuration and a block diagram representing an electrical configuration.

  The X-ray source 1 and the X-ray detector 2 that are arranged to face each other, the transfer device 3 that transfers the inspection object W between them, and the inspection object W that is transferred by the transfer device 3 are the X-ray source 1. The mechanical configuration mainly including the photoelectric sensor 4 that detects arrival at the position where the X-ray detector 2 is disposed is the same as the conventional apparatus shown in FIG. The output from the X-ray detector 2 in which the elements are arranged is taken into the image processing apparatus 5 every moment. The feature of this embodiment is the function of the image processing apparatus 5 shown below.

  The image processing apparatus 5 takes in the detection signal of the inspection object W by the A / D converter 51 and the photoelectric sensor 4 that digitizes the output from the X-ray detector 2, and detects the inspection object W by the photoelectric sensor 4. At the same time, the control unit 52 generates an OFF signal when it passes, and when the signal from the control unit 52 is ON, the output from the A / D converter 51 is taken in, and the inspection object The X-ray fluoroscopic image of the inspection object W stored in the image memory 53 storing the two-dimensional X-ray fluoroscopic image of the object W, the output from the AD converter 51, and the image memory 53 is shown in FIG. Using the plurality of exemplified determination parameters, it is automatically determined whether or not a foreign object is present in the inspection object W, and an OK / NG determination result is sent to an exclusion device (not shown). Automatic determination unit 54 to supply, A touch panel interface 55 for connecting the touch panel 5a, a display control unit 56 for outputting and displaying an image stored in the image memory 53 as a video signal to the touch panel 5a, and a nonvolatile memory for storing a foreign substance sample image by a method described later. Main memory 57, local memory 58 for storing images in image memory 53, images synthesized as described later, and CPU 59 for controlling the whole.

Next, the operation of the embodiment of the present invention having the above configuration will be described together with its usage.
First, a procedure for creating and storing a foreign matter pattern will be described. This foreign matter pattern can be created, for example, at the time of factory shipment or installation of the apparatus, or at any time after installation.

  When creating the foreign matter pattern, for example, as shown in FIG. 2A, an object of a material / shape that can be mixed into various articles as a foreign matter is prepared. That is, stainless steel ball S0, stainless steel wire S1, resin (small) S2, resin (large) S3, rubber (medium) S4, rubber (large) S5, glass ball (medium) S6, glass ball (large) S7, and the like. . In addition to these, an acrylic plate having a predetermined thickness is prepared as a background member so that the background of the foreign matter is not saturated, and a background member made of the acrylic plate or the like as shown in FIG. One of the prepared foreign objects S0 to S7, for example, the foreign object S0 is placed on A, and it is transported by the transport device 3 to read the X-ray fluoroscopic image. Thereby, the fluoroscopic image is stored in the image memory 53, and at the same time, the fluoroscopic image as shown in FIG. 2C is displayed on the monitor of the touch panel 5a.

From this display, the operator touches the foreign object image from the monitor image on the touch panel 5a. As a result, the CPU 59 recognizes the position information on the image via the touch panel interface 55, accesses the address of the image memory 53 corresponding to this position, extracts a portion whose level (dose data) is different from that of the surrounding image, and detects the foreign matter. The data is stored in the nonvolatile memory 57 as the pattern ib0 (u, v). Note that (u, v) is a position on the x and y axes on the monitor screen in the foreign substance pattern, and ib0 is data relating to the X-ray absorption amount of the foreign substance S0 at each position (u, v). The average value of the X-ray transmission dose (X-ray detection data) at each position of the background member A is A, and the X-ray transmission dose (X-ray detection data) at each position of the foreign object S0 is b (u, v), if the X-ray detector 2 has log characteristics,
ib0 (u, v) = A−b (u, v) (1)
It is represented by

  By performing the above operation for the foreign substance Sk (k = 0 to 7), a total of seven foreign substance patterns of ibk (k = 0 to 7) are stored in the nonvolatile memory 57. This foreign matter pattern creation / storage operation is executed in advance as described above, and each foreign matter pattern is stored in the nonvolatile memory 57. Can be used as many times as you want.

  By registering the plurality of foreign matter patterns ibk (u, v) as described above, parameter setting for determining the presence or absence of foreign matter when actually driving the apparatus can be performed by the following procedure.

First, a normal inspection object W, that is, a non-defective inspection object W in which foreign matter is not mixed, is prepared, the inspection object W is transported by the transport device 3, and the X-ray fluoroscopic image is read. In the image processing apparatus 5, the X-ray fluoroscopic image img (x, y) of the normal inspection object W is stored in the image memory 53, and then the data is transferred to the local memory 58. Note that x and y are coordinates in two axial directions orthogonal to each other on the monitor screen, and img represents X-ray transmission data at each coordinate. Then, the X-ray fluoroscopic image of the normal inspection object W and each foreign matter pattern ibk stored in the nonvolatile memory 57 are synthesized. An example of this synthesis method will be described. As shown in FIG. 3, the X-ray fluoroscopic image img (x, y) of the normal inspection object W stored in the local memory 58 and the non-volatile memory 57 are stored. The respective foreign matter patterns ibk are combined to create a composite image Gn (x, y) as shown below.
Gn (x, y) = img (x, y) -igk (xp + u, yp + v) (2)

  In this equation (2), xp and yp are coordinates representing the position where the foreign object pattern igk (u, v) is incorporated into the inspection object image img (x, y), and the inspection object image img (x, y ) Is selected at random. For example, the CPU 59 generates a random function or the like, and that the position is within img (x, y), the value of img (xp, yp) (X-ray What is necessary is just to confirm that (transmission data) is below a certain value. In addition, n is the type of composite image (n = 1, 2,...), And when creating one composite image for each foreign matter pattern ibk (k = 0 to 7), n = 1 to 1. 7 Note that the composite image may create a plurality of composite images for one foreign matter pattern, for example, by changing the position (xp, yp) where each foreign matter pattern is incorporated into the inspection target image. Each foreign object presence inspection object image Gn (x, y) created in this way is stored in the local memory 58.

After completing the creation of each foreign object presence inspection object image Gn (x, y) by the above procedure, the determination parameters in the automatic determination unit 54 are set using these.
In this setting, the CPU 59 displays a setting screen as illustrated in FIG. 4 on the touch panel with monitor 5a. In FIG. 4, M indicates an image display unit, and B1 selects the type of image to be displayed on the image display unit M (a normal inspection object image or a composite image Gn obtained by synthesizing a foreign object pattern). Input boxes B2 to B4 are input boxes for setting threshold values Th1, Th2, and comparison distance Lc, respectively.

  In this display, the operator selects one of the image of the normal inspection object W and the foreign objects S0 to S7 via the input box B1 for designating the image type. Accordingly, the corresponding image data is loaded from the local memory 58 to the image memory 53, and the image is displayed on the image display unit M of the monitor-equipped touch panel 5a. In the example of FIG. 4, the foreign object 0 is selected. At the same time, the automatic determination unit 54 processes the image data to determine the presence or absence of foreign matter. At that time, the threshold values Th1 and Th2 and the comparison distance Lc are appropriately set via the input boxes B2 to B4. The automatic determination unit 54 performs the foreign object detection processing described with reference to FIG. 7 using these determination parameters, adds a red mark on the image display unit M to a region determined to be a foreign object, and displays an NG message. Output.

  The operator inputs so that all the NG messages are displayed in a state where each composite image composed of the foreign objects S0 to S7 is selected, and the OK message is displayed in a state where a normal inspection object image is selected. Each value of threshold values Th1 and Th2 and comparison distance Lc, which are parameters for determination, is adjusted via boxes B2 to B4, and the setting operation is terminated. As a result, when a normal inspection object W that does not have foreign matter passes through when an actual inspection is performed on the line, OK and the inspection target object W that contains foreign matters similar to any of the foreign matters S0 to S7 are mixed. When NG passes, an NG message is output.

  As described above, according to this embodiment, the actual inspection object W is only allowed to pass between the X-ray source 1 and the X-ray detector 2 by the transport device 3 once to obtain the X-ray fluoroscopic image. Since it becomes unnecessary later, the parameter setting for foods such as ice cream whose physical properties change over time can be set exactly the same as that of ordinary articles, and the foreign matter pattern is stored in the nonvolatile memory 57. Since it is stored, an actual sample of the foreign matter is not necessary, and the labor for setting the determination parameter can be greatly reduced.

  By the way, in the above-mentioned embodiment, although the example which set the parameter for determination by X-ray foreign material inspection apparatus was shown, it uses a simulation apparatus different from the X-ray foreign material inspection apparatus actually operated in a line. The determination parameters for the X-ray foreign substance inspection apparatus operating in the line can be set by an operation equivalent to the operation described above at an arbitrary place.

FIG. 5 is a block diagram showing a configuration example of the simulation apparatus.
In this example, the image memory 53, the automatic determination unit 54, the touch panel interface 55, the display control unit 56, the non-volatile memory 57, the local memory 58, and the CPU 59 are exactly the same as those used in the image processing apparatus 5 shown in FIG. The same is true, and the touch-sensitive touch panel 5a is connected via the touch-panel interface 55, and the display content of the touch-sensitive touch panel 5a is the same as the previous example.

  The difference between this simulation apparatus and the image processing apparatus 5 in the previous example is that it does not have a function corresponding to the A-D converter 51 and the control unit 52, and the memory card interface 151 with respect to the image memory 53. The content of the memory card is read through the. The foreign object pattern ibk in the previous embodiment is stored in advance in the nonvolatile memory 57, and an X-ray fluoroscopic image of a normal inspection object W in which no foreign object exists can be obtained by the same procedure as in the previous example. This is read by the X-ray detector, stored in a memory card, and read into the image memory 53 of the simulation apparatus. Then, the X-ray fluoroscopic image img (x, y) of the inspection object W and the foreign object pattern ibk (u, v) in the nonvolatile memory 57 are combined and stored in the local memory 58. The determination parameter can be adjusted by the same procedure as in the above example. The determination parameters adjusted in this way can be set at any time for an actual X-ray foreign substance inspection apparatus manually, through an appropriate storage medium, and further through a LAN or the like.

  Therefore, by using this simulation apparatus, for example, when changing the type of inspection object of the X-ray foreign substance inspection apparatus operating in the line, the X-ray foreign substance inspection apparatus itself continues to operate and continues to operate. The determination parameters for the inspection object can be determined in advance, and the inspection object can be changed in the line and set in the X-ray foreign substance inspection apparatus at the same time, and the line is stopped for setting the determination parameter. Time can be reduced as much as possible.

  In the above embodiment, an example in which X-ray fluoroscopic image data of a normal inspection object is stored in the image memory of the simulation apparatus via a memory card has been described. However, X-rays are transmitted via the Internet, LAN, or the like. Of course, it can be configured to transmit the fluoroscopic image data to the simulation apparatus.

It is a block diagram of embodiment of this invention, and is the figure which writes together and shows the schematic diagram showing a mechanical structure, and the block diagram showing an electric structure. It is explanatory drawing of the creation method of the foreign material pattern by embodiment of this invention, (A) is explanatory drawing of the example of the foreign material which should be prepared, (B) is X-ray fluoroscopy information of the foreign material with an X-ray detector. Explanatory drawing at the time of reading, (C) is an explanatory diagram of an example of an X-ray fluoroscopic image when read in the state of (B). It is explanatory drawing of the synthetic | combination method with the foreign material pattern of the X-ray fluoroscopic image of the test object in embodiment of this invention. It is explanatory drawing of the example of the screen displayed on the touchscreen with a monitor when setting the parameter for determination by embodiment of this invention. It is a block diagram which shows the structural example of the simulation apparatus which concerns on this invention. It is a figure which shows the structural example of the conventional X-ray foreign material inspection apparatus, (A) writes together the schematic diagram showing the mechanical structure seen from the conveyance direction side of the test target object W, and the block diagram showing an electric structure (B) is a schematic diagram showing the mechanical structure seen from the right side surface. It is a graph for demonstrating the example of the parameter for determination used with this kind of X-ray foreign material inspection apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 X-ray source 2 X-ray detector 3 Conveyance apparatus 4 Photoelectric sensor 5 Image processing apparatus 51 AD converter 52 Control part 53 Image memory 54 Automatic determination part 55 Touch-panel interface 56 Display control part 57 Non-volatile memory 58 Local memory 59 CPU
151 Memory card interface W Inspection object S Foreign object

Claims (2)

Image processing using an X-ray fluoroscopic image of the inspection object obtained by irradiating X-rays while conveying the inspection object by the conveying means between the X-ray source and the X-ray detector arranged opposite to each other In the X-ray foreign matter inspection apparatus provided with the image processing means for determining the presence or absence of foreign matters in the inspection object using the determination parameters set in advance by the setting means,
A storage means for storing a plurality of types of foreign matter pattern images, and an X-ray fluoroscopic image of the inspection object without foreign matter imaged by the X-ray detector include a plurality of types of foreign matter pattern images stored in the storage means. An X-ray foreign substance inspection characterized in that it comprises an image synthesis means for selectively synthesizing arbitrary objects, and the judgment parameter can be set by the setting means using the synthesized image apparatus. Foreign matter used by image processing means in an X-ray foreign matter inspection apparatus that determines the presence or absence of foreign matter in an inspection target by using image processing using an X-ray fluoroscopic image of the inspection target using preset determination parameters An apparatus for setting a determination parameter,
An image processing means having the same function as that used in the X-ray foreign substance inspection apparatus, a storage means for storing a plurality of foreign substance patterns, and an X of the inspection object without foreign substances imaged by the X-ray foreign substance inspection apparatus Data capturing means for loading a fluoroscopic image, and an image that selectively synthesizes an X-ray fluoroscopic image of the captured inspection object and any one of a plurality of types of foreign matter pattern images stored in the storage means A determination parameter setting apparatus for an X-ray foreign substance inspection apparatus, comprising: a combining unit; and a setting unit that sets a determination parameter used in the image processing unit using the combined image.

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