X-ray inspection device and method for calculating the cutting position of an object.

Abstract

The cutting positions are calculated in two directions: perpendicular to the direction of transport of the item and horizontally. [Solution] The X-ray inspection apparatus 1 outputs position information for cutting a block-shaped article into article pieces of predetermined mass in two directions from an X-ray image obtained by irradiating the block-shaped article, which is transported as an object to be inspected W, with X-rays. The apparatus comprises a total mass acquisition unit 11 that acquires the total mass of the block-shaped article, a division position calculation unit 12 that calculates the division position of the block-shaped article based on the total mass of the block-shaped article, a target mass value of the article piece, and at least one target value of the length and width of the article piece from the X-ray image, and an output unit 8 that outputs position information for cutting the block-shaped article into article pieces to the outside based on the division position calculation unit 12.

Description

Technical Field

[0001] The present invention relates to an X-ray inspection apparatus and an article cutting position calculation method for irradiating an inspected object to be conveyed with X-rays and inspecting the quality of the inspected object using an X-ray image obtained when the X-rays are irradiated.

Background Art

[0002] An X-ray inspection apparatus has been conventionally known as an apparatus that inspects an inspected object, such as raw meat, fish, processed food, medicine, etc., using an X-ray image obtained when the inspected object is irradiated with X-rays.

[0003] By the way, in this type of X-ray inspection apparatus, when creating sliced meat with uniform weight and volume from materials with varying thicknesses and widths, such as frozen foods, filleted fish, and block meats like beef, pork, and chicken, it is necessary to specify the cross-sectional position. For this reason, in conventional X-ray inspection apparatuses, as disclosed in Patent Document 1 and Patent Document 2 below, for an article being conveyed, a cutting position for cutting in a direction intersecting the conveyance direction is specified.

[0004] More specifically, in the X-ray inspection apparatuses of Patent Document 1 and Patent Document 2 below, from an X-ray transmission image obtained by irradiating an article with X-rays while conveying the article, the density level of each pixel in the region occupied by the article for each 1-pixel line in the direction intersecting the conveyance direction of the article is converted into mass, and the mass obtained for each 1-pixel line is sequentially added along the conveyance direction, thereby obtaining an article mass corresponding to the conveyance amount of the article. When the obtained article mass reaches the article mass of a previously specified one divided piece, the 1-pixel line at that time is specified as the cutting position when cutting out each divided piece from the article.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

[0006] However, the conventional X-ray inspection apparatus methods disclosed in Patent Documents 1 and 2 mentioned above identify cutting positions in a direction intersecting the transport direction of the article, but they do not identify cutting positions for cutting horizontally to the transport direction of the article. Moreover, since the cutting positions are calculated on a pixel-by-pixel basis, there is a possibility of a large deviation from the target mass value.

[0007] Therefore, the present invention has been made in view of the above problems, and aims to provide an X-ray inspection apparatus and a method for calculating the cutting position of an article that can calculate the cutting position in two directions, perpendicular and horizontal, with respect to the conveying direction of the article. [Means for solving the problem]

[0008] To achieve the above objective, the X-ray inspection apparatus described in claim 1 of the present invention is an X-ray inspection apparatus 1 that outputs positional information for cutting a block-shaped article, which is transported as an object to be inspected W, into article pieces of a predetermined mass in two directions from an X-ray image obtained by irradiating the block-shaped article with X-rays, The total mass acquisition unit 11 acquires the total mass of the aforementioned block-shaped article, A division position calculation unit 12 calculates the division position of the block article based on the total mass of the block article, the target mass value of the article piece, and at least one target value of the length and width of the article piece, from the X-ray image. The invention is characterized by comprising an output unit 8 that outputs position information to the outside for cutting the block-shaped article into article pieces based on the division position calculated by the division position calculation unit.

[0009] The X-ray inspection apparatus described in claim 2 of the present invention is an X-ray inspection apparatus according to claim 1, The division position calculation unit 12 includes a first interpolation calculation means 12a that calculates a provisional cutting position in one of the coordinate axis directions of the X-ray image, with the axis directions perpendicular and horizontal to the transport direction A of the block-shaped article, from the corresponding target value, and calculates the cutting position in the one coordinate axis direction by performing an interpolation calculation to a position where the mass between the provisional cutting positions is an integer multiple of the target mass value, The present invention is characterized by having a second interpolation calculation means 12b that calculates the cutting position in the other coordinate axis direction by performing an interpolation calculation to determine a provisional cutting position in the other coordinate axis direction from the corresponding target value and interpolate the mass between the provisional cutting positions to a position where the mass becomes the target mass value.

[0010] The X-ray inspection apparatus described in claim 3 of the present invention is an X-ray inspection apparatus according to claim 2, The first interpolation calculation means 12a is characterized in that it uses the pixel position of the provisional cutting position in the one coordinate axis direction as a reference position, and calculates the cutting position in the one coordinate axis direction based on the mass obtained by increasing or decreasing the pixel position in the one coordinate axis direction, which is the mass of the pixel position that passes through the target mass value and the mass of the line image region in the other coordinate axis direction of that pixel position.

[0011] The X-ray inspection apparatus described in claim 4 of the present invention is an X-ray inspection apparatus according to claim 1, The output unit 8 is characterized by outputting the distance and number of division positions of the block-shaped article from reference positions in the direction perpendicular and horizontal with respect to the transport direction A of the block-shaped article.

[0012] The method for calculating the cutting position of an article according to claim 5 of the present invention includes the steps of setting a target value for at least one of the length and width of an article piece of a block-shaped article that is transported as an object to be inspected W, and a target mass value of the article piece, The steps include: acquiring an X-ray image of the block-shaped article; A step of obtaining the total mass of the aforementioned block-shaped article, A step of calculating the temporary cutting position in one of the coordinate axes, which is perpendicular to the transport direction of the block-shaped article and is horizontal to the transport direction, calculating a cutting position in the direction of one coordinate axis; calculating a cutting position in the direction of the other coordinate axis; outputting the distances and numbers of the cutting positions from the reference positions in the directions of the one and the other coordinate axes, and characterized by including the above steps.

Advantages of the Invention

[0013] According to the present invention, for two directions perpendicular and horizontal to the conveying direction of the massive article, the cutting positions for cutting the massive article into article pieces (individual pieces) of a desired mass can be calculated by one inspection. Moreover, since the cutting positions are calculated in sub-pixel units, the cutting positions can be calculated with high accuracy.

Brief Description of the Drawings

[0014] [Figure 1] It is a block diagram showing a schematic configuration of an X-ray inspection apparatus according to the present invention. [Figure 2] It is a flowchart of a method 1 for calculating an article cutting position in an X-ray inspection apparatus according to the present invention. [Figure 3] It is a flowchart of a method for calculating a cutting position in FIG. 2. [Figure 4] (a) - (g) are diagrams showing specific examples of a method 1 for calculating an article cutting position. [Figure 5] It is a flowchart of a method 2 for calculating an article cutting position in an X-ray inspection apparatus according to the present invention. [Figure 6] (a) - (g) are diagrams showing specific examples of a method 2 for calculating an article cutting position. [Figure 7] It is an explanatory diagram of cutting position information externally output by an output unit of an X-ray inspection apparatus according to the present invention.

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.

[0016] As shown in Figure 1, the X-ray inspection apparatus 1 of this embodiment images the object to be inspected W (a block-shaped article to be inspected) being transported on an inspection line, performs image processing on the inspection image of the object to be inspected W obtained by imaging to inspect the quality of the object to be inspected W (foreign matter, defects, etc.), and further outputs cutting position information of the object to be inspected W corresponding to a specified target mass. The apparatus is generally configured to include a transport unit 2, an imaging unit 3, an X-ray image storage unit 4, a parameter setting unit 5, a display operation unit 6, an image processing unit 7, and an output unit 8.

[0017] The transport unit 2 is arranged in the required number on the inspection line and sequentially transports the block-shaped articles W, which are the objects to be inspected, at predetermined intervals in the transport direction A. For example, it is configured by supporting a conveyor (not shown) in a housing (not shown) that can sequentially transport the objects W in the transport direction A (rightward in Figure 1) by winding a loop-shaped transport belt 2b around multiple transport rollers 2a. The transport rollers 2a are rotationally driven by a motor (not shown) and controlled to obtain a predetermined transport speed.

[0018] The imaging unit 3 acquires inspection images of the object W being transported by the transport unit 2, and comprises an X-ray generator 3a positioned at a predetermined height above an inspection space (not shown) in the middle of the transport unit 2, and an X-ray detector 3b positioned inside the transport unit 2 opposite the X-ray generator 3a.

[0019] The X-ray generator 3a generates X-rays of wavelength and intensity corresponding to the tube current and tube voltage using a known X-ray tube, and is configured to irradiate the object to be inspected W or samples (good workpieces, foreign objects, etc. of the object to be inspected W) on the conveyor belt 2b with fan-beam-shaped X-rays perpendicular to the conveying direction A of the conveying unit 2 through the X-ray window of an enclosure (not shown).

[0020] The tube current and tube voltage of the X-ray tube are preferably adjusted according to the material and size of the object W under inspection (especially the dimensions in the direction of X-ray transmission). For new varieties, the settings are determined or selected by test imaging using the object W under inspection or a sample to obtain appropriate contrast.

[0021] The X-ray detector 3b includes an X-ray line sensor, which contains a scintillator and a photodiode array (not shown). The scintillator converts X-rays into light, and the photodiode array converts this light into an electrical signal to output an X-ray image based on X-ray transmission data. The X-ray detector 3b may also generate and output the X-ray image using a direct conversion type semiconductor element.

[0022] The X-ray image storage unit 4 temporarily stores the X-ray image obtained from the X-ray transmission data received from the X-ray detector 3b of the imaging unit 3 as the inspection image of the object W to be inspected.

[0023] The parameter setting unit 5 sets the parameters necessary when dividing a block of article W, which is the object to be inspected, into multiple article pieces (individual pieces) of a predetermined mass. Specifically, the target mass value of the article pieces and at least one of the length and width of the article pieces are set as parameters when dividing the block of article W into multiple pieces.

[0024] The display operation unit 6 is operated to switch the transport unit 2 and imaging unit 3 ON / OFF, and to perform various settings and displays necessary when inspecting the quality of the block-shaped article W under inspection. It displays inspection images of the object under inspection W and inspection results of the object under inspection W stored in the X-ray image storage unit 4 on the display screen, and displays operation buttons on the display screen to give instructions for various settings and displays related to the quality inspection of the object under inspection W. In Figure 1, the parameter setting unit 5 and the display operation unit 6 are configured separately, but the display operation unit 6 may also include the parameter setting unit 5.

[0025] The image processing unit 7 is provided as part of the control unit (not shown) and controls the operation of each part of the X-ray inspection apparatus 1 (transport unit 2, imaging unit 3, X-ray image storage unit 4, parameter setting unit 5, display operation unit 6) based on a program stored in the storage unit (not shown), and also performs various processes including processing the inspection image of the object to be inspected W, and includes a total mass acquisition unit 11 and a division position calculation unit 12.

[0026] The control unit is a device that comprehensively controls the operation of the X-ray inspection apparatus 1, comprising one or more processors and their peripheral circuits, and includes, for example, a CPU (Central Processing Unit) or GPU (Graphics Processing Unit), a DSP (Digital Signal Processor), an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc.

[0027] The total mass acquisition unit 11 acquires the total mass of the block-shaped article W, which is the object to be inspected, from the X-ray image stored in the X-ray image storage unit 4. Specifically, in the X-ray image stored in the X-ray image storage unit 4, pixels with a density of a predetermined level (belt density of the transport belt 2b of the transport unit 2) or higher are defined as the region of the block-shaped article, and the density of that region is converted into mass to determine the total mass of the block-shaped article.

[0028] The division position calculation unit 12 calculates the division positions of the block article based on the X-ray image stored in the X-ray image storage unit 4. These calculations are performed by determining the division positions of the block article in two directions: a pre-cutting position and a cutting position in the direction perpendicular and horizontal with respect to the transport direction A on the transport surface, which is necessary to divide the block article equally with respect to the target values. The unit comprises a first interpolation calculation means 12a and a second interpolation calculation means 12b.

[0029] The first interpolation calculation means 12a calculates the cutting position in the direction of one coordinate axis (X-axis) of the X-ray image, which has axes perpendicular and horizontal with respect to the transport direction A on the transport surface, by determining the provisional cutting position in the direction of one coordinate axis from the corresponding target value (for example, the target value of the length of the item piece), and interpolates to a position where the mass between the determined provisional cutting positions is an integer multiple of the target mass value.

[0030] The second interpolation calculation means 12b calculates the cutting position in the other coordinate axis direction (Y axis) by performing an interpolation calculation to determine the provisional cutting position in the other coordinate axis direction from the corresponding target value (for example, the target value of the width of the article piece) and interpolating the mass between the determined provisional cutting positions to a position where the mass becomes the target mass value.

[0031] Based on the cutting positions calculated by the first interpolation calculation means 12a and the second interpolation calculation means 12b, the output unit 8 outputs the distance from the references in the perpendicular and horizontal directions (one reference position TP11 and the other reference positions TP21, TP31, TP41, which will be described later) with respect to the transport direction A on the transport surface, and the number of cuts, as cutting position information to the cutting device 9. Specific examples of cutting position information will be described later.

[0032] The cutting device 9 cuts the block-shaped article W, which is the object to be inspected and is sequentially conveyed by the conveying unit 2, into multiple article pieces of a predetermined mass based on the cutting position information input from the output unit 8.

[0033] Next, we will explain the method 1 for calculating the cutting position of an article when inspecting a block-shaped article as an object to be inspected W using the X-ray inspection apparatus 1 configured as described above, along with specific examples, with reference to Figures 2 to 4.

[0034] [Method 1 for calculating the cutting position of an item]... A method for calculating one of the cutting positions first. In Figure 2, the parameter setting unit 5 sets the parameters necessary to calculate the cutting position of the block-shaped article W, which is the object to be inspected (ST1). Specifically, the parameter setting unit 5 sets the target value (length or width of the article piece) and its tolerance range for the article piece of the block-shaped article W, and the target mass and its tolerance range for the article piece of the block-shaped article as parameters.

[0035] Once the above parameters are set, it is determined whether or not to start operation (ST2). If it is determined that operation should start (ST2-Yes), the imaging unit 3 images the block-shaped item (food) as the object to be inspected W and acquires an X-ray image (ST3). The acquired X-ray image is stored in the X-ray image storage unit 4.

[0036] Next, the total mass of the bulky object is obtained from the X-ray image stored in the X-ray image storage unit 4 by the total mass acquisition unit 11 of the image processing unit 7 (ST4). Specifically, the total mass acquisition unit 11 identifies the region of the bulky object as pixels with a density equal to or greater than the belt density of the transport belt 2b of the transport unit 2 in the X-ray image stored in the X-ray image storage unit 4, and converts the density of that region into mass to determine the total mass of the bulky object. In the examples of Figures 4(a) to (g), the density of the region WG of the bulky object, indicated by the shaded area, is converted into mass to determine the total mass of the bulky object.

[0037] Next, the first interpolation calculation means 12a of the division position calculation unit 12 calculates one of the temporary cutting positions (ST5). The first interpolation calculation means 12a calculates one of the temporary cutting positions in the direction perpendicular to the transport direction A on the transport surface (one of the coordinate axes: the X-axis direction), based on the total mass of the block-shaped article, the parameterized target value and its allowable range, and the position where no unnecessary article pieces (where the width and mass are outside the allowable range) are created from the target mass and its allowable range. Specifically, as shown in Figure 4(b), the temporary cutting positions TP11 (leading end of the block-shaped article), TP12, TP13, and TP14 (rear end of the block-shaped article) perpendicular to the transport direction A on the transport surface are calculated as one of the temporary cutting positions.

[0038] Next, the first interpolation calculation means 12a of the division position calculation unit 12 calculates one of the cutting positions according to the flowchart in Figure 3, which will be described later (ST6), and determines whether or not there is another cutting position (ST7). Specifically, as shown in Figure 4(c), one of the temporary cutting positions TP11 is calculated as one of the reference positions and the cutting position VP11 is calculated as one of the cutting positions in the direction perpendicular to the transport direction A on the transport surface (one of the coordinate axes: X-axis direction).

[0039] In ST7, if it is determined that there is one of the following cutting positions (ST7-Yes), the process returns to ST6. Specifically, as shown in Figure 4(d), the cutting position VP12 perpendicular to the transport direction A on the transport surface is calculated as the next cutting position, and the cutting position VP13 shown in Figure 4(e) is then calculated as the next cutting position.

[0040] In response to this, if it is determined that there is no cutting position for one of the following (ST7-No), the second interpolation calculation means 12b of the division position calculation unit 12 calculates the other temporary cutting position (ST8). In Figure 4, only the other temporary cutting positions TP21, TP31, and TP41, which serve as the reference position for the other, are shown, but the other temporary cutting position is calculated using the same method as the first temporary cutting position TP11, TP12, TP13, and TP14 described above. That is, the second interpolation calculation means 12b calculates the other temporary cutting position in the horizontal direction (the other coordinate axis: Y-axis direction) with respect to the transport direction A on the transport surface, based on the total mass of the block-shaped article, the parameterized target value and its allowable range, and the position where no unnecessary article pieces (where the width and mass are outside the allowable range) are created from the target mass and its allowable range.

[0041] Next, the second interpolation calculation means 12b of the division position calculation unit 12 calculates the other cutting position according to the flowchart in Figure 3, which will be described later (ST9), and determines whether or not there is a next other cutting position (ST10). If it is determined in ST10 that there is a next other cutting position (ST10-Yes), the process returns to ST9. Specifically, as shown in Figure 4(e), cutting positions HP11 and HP12 in the horizontal direction (the other coordinate axis: Y-axis direction) with respect to the transport direction A on the transport surface are calculated as the other cutting positions. Subsequently, as shown in Figure 4(f), cutting positions HP21 and HP22 in the horizontal direction with respect to the transport direction A on the transport surface are calculated as the next other cutting positions. Furthermore, as shown in Figure 4(g), cutting positions HP31, HP32, and HP33 in the horizontal direction with respect to the transport direction A on the transport surface are calculated as the next other cutting positions.

[0042] In response to this, if ST10 determines that there is no other cutting position (ST10-No), it is determined whether or not the operation is finished (ST11).

[0043] In ST11, if it is determined that the operation has ended (ST11-Yes), the process of calculating the cutting position is terminated. Conversely, if it is determined that the operation has not ended (ST11-No), the process returns to ST3.

[0044] Next, the method for calculating the cutting position in Figure 2 described above will be explained with reference to the flowchart in Figure 3. This cutting position calculation process is performed by the first interpolation calculation means 12a and the second interpolation calculation means 12b of the division position calculation unit 12.

[0045] To calculate the cutting position in Figure 2, first, the mass MB from the reference position perpendicular to the transport direction A on the transport surface (one coordinate axis: X-axis direction) and the reference position horizontally (the other coordinate axis: Y-axis direction) to the temporary cutting position is calculated (ST21). To explain further, the mass from the reference position perpendicular to the transport direction A on the transport surface (the leading or trailing end of the block-shaped article, the calculated vertical cutting position) and the reference position horizontally (the upper or lower horizontal end of the block-shaped article between the calculated vertical cutting positions) to the next temporary cutting position is calculated as the mass MB by converting the density of the corresponding pixels in the X-ray image.

[0046] For example, in Figure 4, for the direction perpendicular to the transport direction A on the transport surface, the mass MB from the reference position TP11 perpendicular to the transport direction A on the transport surface to the next temporary cutting position TP12, the mass MB from the calculated cutting position VP11 to the next temporary cutting position TP13, and the mass MB from the calculated cutting position VP12 to the next temporary cutting position TP14 are calculated.

[0047] The target value (length or width of the item piece), which is a parameter, is set as a distance. Therefore, the mass of the preliminary cutting position is calculated by adding an n-pixel line with a pixel width n corresponding to the distance from the starting line including the reference position to the target value, in sub-pixel units.

[0048] Next, it is determined whether the calculated mass MB is less than or equal to the target mass (ST22). If it is determined in ST22 that the calculated mass MB is less than or equal to the target mass (ST22-Yes), the line mass ML obtained by shifting the pixel position by one in the direction of increasing the mass is obtained and added to the mass MB (ST23). To explain further, the line mass ML of a one-pixel line at a position one pixel added from the pixel containing the cutting position is calculated and added to the mass MB.

[0049] Next, it is determined whether the mass obtained by adding the line mass ML to the mass MB is less than or equal to the target mass (ST24). If ST24 determines that the mass obtained by adding the line mass ML to the mass MB is not less than or equal to the target mass (ST24-No), the cutting position is calculated from the line mass ML and the mass MB before addition (ST25). To explain further, the cutting position is calculated by interpolating the pixels that will become the target mass from the line mass ML and the block mass MB before addition in sub-pixel units. A sub-pixel is the smallest unit of distance obtained by dividing one pixel by a predetermined division width.

[0050] In response to this, if ST24 determines that the mass obtained by adding the line mass ML to the mass MB is less than or equal to the target mass (ST24-Yes), the process returns to ST25.

[0051] On the other hand, in ST22, if it is determined that the calculated mass MB is not less than or equal to the target mass (ST22-No), the line mass ML is obtained by shifting the pixel position by one in the direction of reducing the mass, and this is subtracted from the mass MB (ST26). To explain further, the line mass ML of a one-pixel line at a position one pixel away from the pixel containing the cutting position is calculated, and this line mass ML is subtracted from the mass MB.

[0052] Next, it is determined whether the mass obtained by subtracting the line mass ML from the mass MB is less than or equal to the target mass (ST27). If it is determined in ST27 that the mass obtained by subtracting the line mass ML from the mass MB is less than or equal to the target mass (ST27-No), the cutting position is calculated from the line mass ML and the mass MB before subtraction (ST28). To explain further, the cutting position is calculated by interpolating the pixels that will be the target mass from the line mass ML and the mass MB before subtraction on a sub-pixel basis.

[0053] In contrast, if ST27 determines that the mass is not below the target mass (ST27-No), the process returns to ST26.

[0054] As described above, the cutting positions VP11, VP12, VP13 (=TP14) perpendicular to the transport direction A on the transport surface, and the cutting positions HP11, HP12, HP21, HP22, HP31, HP32, HP33 horizontal to the transport direction A on the transport surface are calculated, as shown in Figure 4(g).

[0055] Then, the cutting positions VP11, VP12, VP13, HP11, HP12, HP21, HP22, HP31, HP32, HP33, which are perpendicular and horizontal to the transport direction A on the transport surface calculated by the above method 1 for calculating the cutting position of the article, are displayed superimposed on the X-ray image of the block-shaped article W being inspected on the display screen of the operation display unit 6.

[0056] By the way, in the above method 1 for calculating the cutting position of an article, the calculation of the provisional cutting position and the cutting position in the direction perpendicular and horizontal with respect to the transport direction A on the transport surface is performed from the leading end side of the block-shaped article, but it may also be performed from the trailing end side of the block-shaped article.

[0057] Furthermore, in the above method 1 for calculating the cutting position of an item, the cutting position is calculated after first calculating the temporary cutting position in the direction perpendicular to the transport direction A on the transport surface, and then the cutting position is calculated after first calculating the temporary cutting position in the direction horizontal to the transport direction A on the transport surface, but the method is not limited to this.

[0058] In other words, the cutting position may be calculated after calculating the temporary cutting position in the horizontal direction relative to the transport direction A on the transport surface, and then the cutting position may be calculated after calculating the temporary cutting position in the perpendicular direction relative to the transport direction A on the transport surface. In this case, the calculation of the temporary cutting position and the cutting position in the perpendicular and horizontal directions relative to the transport direction A on the transport surface may be performed from either the upper or lower end of the block-shaped article.

[0059] Next, a method 2 for calculating the cutting position of an article when inspecting a block-shaped article as an object to be inspected W using the X-ray inspection apparatus 1 configured as described above, and specific examples will be explained with reference to Figures 5 and 6.

[0060] [Method 2 for calculating the cutting position of an item]... A method for calculating the cutting position for each piece of an item. In Figure 5, the parameter setting unit 5 sets the parameters necessary to calculate the cutting position of the block-shaped article W, which is the object to be inspected (ST31). Specifically, the parameter setting unit 5 sets the target value (length or width of the article piece) and its tolerance range for the article piece of the block-shaped article W, and the target mass and its tolerance range for the article piece of the block-shaped article as parameters.

[0061] Once the above parameters are set, it is determined whether or not to start operation (ST32). If it is determined that operation should start (ST32-Yes), the bulky item (food) as the object to be inspected W is imaged and an X-ray image is acquired (ST33). The acquired X-ray image is stored in the X-ray image storage unit 4.

[0062] Next, the total mass of the bulky object is obtained from the X-ray image stored in the X-ray image storage unit 4 by the total mass acquisition unit 11 of the image processing unit 7 (ST34). Specifically, the total mass acquisition unit 11 identifies the region of the bulky object as pixels with a density equal to or greater than the belt density of the transport belt 2b of the transport unit 2 in the X-ray image stored in the X-ray image storage unit 4, and converts the density of that region into mass to determine the total mass of the bulky object. In the examples of Figures 6(a) to (g), the density of the region WG of the bulky object, indicated by the shaded area, is converted into mass to determine the total mass of the bulky object.

[0063] Next, the first interpolation calculation means 12a of the division position calculation unit 12 calculates one of the temporary cutting positions (ST35). The first interpolation calculation means 12a calculates one of the temporary cutting positions in the direction perpendicular to the transport direction A on the transport surface (one of the coordinate axes: the X-axis direction), based on the total mass of the block-shaped article, the parameterized target value and its allowable range, and the position where no unnecessary article pieces (where the width and mass are outside the allowable range) are created from the target mass and its allowable range. Specifically, as shown in Figure 6(b), the temporary cutting positions TP11 (leading end of the block-shaped article), TP12, TP13, and TP14 (rear end of the block-shaped article) perpendicular to the transport direction A on the transport surface are calculated as one of the temporary cutting positions.

[0064] Next, one of the cutting positions is calculated according to the flowchart in Figure 3 described above (ST36). Specifically, as shown in Figure 6(c), the cutting position VP11 perpendicular to the transport direction A on the transport surface is calculated as one of the cutting positions.

[0065] Next, the temporary cutting position of the other side is calculated (ST37). Although Figure 6 only shows the temporary cutting positions TP21, TP31, and TP41 of the other side, which serve as the reference position for the other side, the temporary cutting position of the other side is calculated using the same method as described above for the temporary cutting positions TP11, TP12, TP13, and TP14 of the first side. That is, the temporary cutting position of the other side is calculated horizontally with respect to the transport direction A on the transport surface (the coordinate axis of the other side: Y-axis direction), and is determined by the total mass of the block-shaped article, the parameterized target value and its tolerance range, and the target mass and its tolerance range to ensure that no unnecessary article pieces (where the width and mass are outside the tolerance range) are created.

[0066] Next, the other cutting position is calculated according to the flowchart in Figure 3 above (ST38), and it is determined whether or not there is another cutting position for the other (ST39). If it is determined in ST39 that there is another cutting position for the other (ST39-Yes), the process returns to ST38. Specifically, as shown in Figure 6(d), the cutting position HP11 in the horizontal direction relative to the transport direction A on the transport surface is calculated as the other cutting position. Next, the cutting position HP12 in the horizontal direction relative to the transport direction A on the transport surface is calculated as the next other cutting position.

[0067] If it is determined that there is no other cutting position (ST39-No), then it is determined whether or not there is another cutting position (ST40).

[0068] In ST40, if it is determined that there is one of the following cutting positions (ST40-Yes), the process returns to ST36. Specifically, as shown in Figure 6(d), VP12 perpendicular to the transport direction A on the transport surface is calculated as the next cutting position. Then, as shown in Figure 6(f), the cutting positions HP21 and HP22 horizontally on the transport surface relative to the transport direction A are calculated in that order as the next other cutting positions. After that, as shown in Figure 6(g), the cutting positions HP31, HP32, and HP33 horizontally on the transport surface relative to the transport direction A are calculated in that order as the next other cutting positions.

[0069] In response to this, if it is determined that there is no cutting position (ST40-No), it is determined whether or not the operation is finished (ST41).

[0070] In ST41, if it is determined that the operation has ended (ST41-Yes), the process of calculating the cutting position is terminated. Conversely, if it is determined that the operation has not ended (ST41-No), the process returns to ST33.

[0071] By the way, in the method 2 for calculating the cutting position of an article described above, the cutting position of each article piece is calculated from the upper end of the tip of the lump-shaped article, but the cutting position of each article piece may also be calculated from the lower end of the tip of the lump-shaped article.

[0072] In other words, the above-described method 2 for calculating the cutting position of an article only requires that the cutting position be calculated for each article piece of the lump-shaped article. In addition to the above, methods can be employed to calculate the cutting position for each article piece from the upper or lower end of the rear end of the lump-shaped article, from the front or rear end of the upper end of the lump-shaped article, or from the front or rear end of the lower end of the lump-shaped article.

[0073] Furthermore, TP21, TP31, and TP41, which serve as reference positions for calculating the cutting position, are the cutting position information output to the cutting device 9. In addition, in order to determine a position where no unnecessary pieces of material are created based on the parameterized target value and its tolerance range, one temporary cutting position and the other temporary cutting position are calculated using the target value of the material piece (length or width of the material piece) and its tolerance range. However, it is also possible to calculate only one temporary cutting position based on the target value set for one side of the material piece, and calculate the other position based only on the target weight.

[0074] Next, an example of cutting position information output externally by the output unit 8 will be explained with reference to Figure 7. Here, the cutting position information obtained by the method for calculating the cutting position of an item 1 will be used as an example.

[0075] Figure 7 shows the calculation results of the cutting position using Method 1 for calculating the cutting position of an item, based on the flowcharts in Figures 2 and 3, when one reference position is TP11 and the other reference positions are TP21, TP31, and TP41.

[0076] From the calculation results of the cutting positions in Figure 7, we can obtain information on the relative distance from one reference position TP11 to one cutting position (a cutting position perpendicular to the transport direction A), and information on the relative distance from the other reference positions TP21, TP31, TP41 to the other cutting position (a cutting position horizontal to the transport direction A).

[0077] Specifically, as shown in Figure 7, information on the relative distances A1, A2, and A3 from one reference position TP11 to one cutting position VP11, VP12, and VP13 is obtained. In addition, information on the relative distances B1 and B2 from the other reference position TP21 to the other cutting position HP11 and HP12 is obtained, information on the relative distances B3 and B4 from the other reference position TP31 to the other cutting position HP21 and HP22 is obtained, and information on the relative distances B5, B6, and B7 from the other reference position TP41 to the other cutting position HP31, HP32, and HP33 is obtained.

[0078] As a result, the output unit 8 outputs the cutting position information via message output to the cutting device 9 in the following order: STX (start of message), identification code (identification code for transmitting cutting position information), number of cuts from one reference position TP11: 3, number of cuts from the other reference positions TP21, TP31, TP41: 2, 2, 3, relative distance (unit [mm]) from one reference position TP11 to one cutting position VP11, VP12, VP13: A1, A2, relative distance (unit [mm]) from the other reference position TP21, TP31, TP41 to the other cutting position HP11, HP12, HP21, HP22, HP31, HP32, HP33: B1, B2, B3, B4, B5, B6, B7, and ETX (end of message).

[0079] Thus, according to this embodiment, it is possible to calculate the cutting position in two directions—perpendicular to the transport direction and horizontal to the transport direction—on the transport surface on which the block-shaped article to be inspected, so that the individual pieces of the block-shaped article have the desired mass in a single inspection. Moreover, the cutting position of the block-shaped article to be inspected can be calculated with high accuracy by performing calculations at the sub-pixel level.

[0080] The best mode of the X-ray inspection apparatus and article cutting position calculation method according to the present invention has been described above, but the present invention is not limited by this description and drawings. That is, other modes, examples, and operational techniques based on this embodiment, as made by those skilled in the art, are all included in the scope of the present invention. [Explanation of Symbols]

[0081] 1. X-ray inspection device 2. Conveying section 2a Conveyor roller 2b Conveyor belt 3. Imaging Unit 3a X-ray generator 3b X-ray detector 4 X-ray image storage section 5. Parameter setting section 6 Display operation section 7 Image Processing Unit 8 Output section 9 Cutting device 11 Overall mass acquisition section 12 Division position calculation section 12a First interpolation calculation means 12b Second interpolation calculation means W Object to be inspected (bulk item) Region of a bulky object in a WG X-ray image A Conveying direction TP11 One of the temporary cutting positions (one of the reference positions) TP12, TP13, TP14 One of the temporary cutting positions TP21, TP31, TP41: Other temporary cutting position (other reference position) VP11, VP12, VP13 One cutting position HP11, HP12, HP21, HP22, HP31, HP32, HP33 Cutting position of the other

Claims

1. An X-ray inspection apparatus (1) that outputs positional information for cutting a block-shaped article (W) into article pieces of a predetermined mass in two directions from an X-ray image obtained by irradiating the block-shaped article with X-rays, A total mass acquisition unit (11) that acquires the total mass of the aforementioned block-shaped article, A division position calculation unit (12) calculates the division position of the block article based on the total mass of the block article, the target mass value of the article piece, and at least one target value of the length and width of the article piece, from the X-ray image, An X-ray inspection apparatus characterized by comprising: an output unit (8) that outputs position information to the outside for cutting the block-shaped article into article pieces based on the division position calculated by the division position calculation unit.

2. The division position calculation unit (12) includes a first interpolation calculation means (12a) that calculates a provisional cutting position in the direction of one of the coordinate axes of the X-ray image, with the axes perpendicular and horizontal to the transport direction (A) of the block-shaped article, from the corresponding target value, and calculates the cutting position in the direction of the one coordinate axis by performing an interpolation calculation to a position where the mass between the provisional cutting positions is an integer multiple of the target mass value. The X-ray inspection apparatus according to claim 1, further comprising: a second interpolation calculation means (12b) that calculates the cutting position in the other coordinate axis direction by performing an interpolation calculation to determine a provisional cutting position in the other coordinate axis direction from the corresponding target value and interpolating the mass between the provisional cutting positions to a position where the mass becomes the target mass value.

3. The X-ray inspection apparatus according to claim 2, wherein the first interpolation calculation means (12a) uses the pixel position of the provisional cutting position in the one coordinate axis direction as a reference position, and calculates the cutting position in the one coordinate axis direction based on the mass obtained by increasing or decreasing the pixel position in the one coordinate axis direction, which is the mass of the pixel position that passes through the target mass value and the mass of the line image region in the other coordinate axis direction of that pixel position.

4. The X-ray inspection apparatus according to claim 1, characterized in that the output unit (8) outputs the distance and number of division positions of the block-shaped article from reference positions in the direction perpendicular and horizontal with respect to the transport direction (A) of the block-shaped article.

5. A step of setting a target value for at least one of the length and width of a piece of the block-shaped article to be transported as the object to be inspected (W), and a target mass value for the piece of the article. The steps include: acquiring an X-ray image of the block-shaped article; A step of obtaining the total mass of the aforementioned block-shaped article, A step of calculating the temporary cutting position in one of the coordinate axes, which is perpendicular to the transport direction of the block-shaped article and is horizontal to the transport direction, The steps include calculating the cutting position in the direction of one of the coordinate axes, The step of calculating the cutting position in the other coordinate axis direction, A method for calculating the cutting position of an article, characterized by including the step of outputting the distance and number of cutting positions from reference positions in the coordinate axis directions of one and the other.

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