X-ray inspection device

Abstract

To provide an X-ray inspection device capable of aligning a position of an optical axis of X-rays with a position of an X-ray line sensor.SOLUTION: An X-ray inspection device having an inspection mode in which X-rays are irradiated onto an inspection object conveyed sequentially, and the inspection object is inspected using an X-ray image acquired from the X-rays that have passed through the inspection object and have been detected by an X-ray line sensor, comprises: a moving mechanism which reciprocally moves the X-ray line sensor in a direction parallel to a conveying direction of the inspection object; an imaging mode execution unit which can execute an imaging mode in which the X-rays are irradiated to the inspection object stopped at an inspection position through which an optical axis of the X-rays passes and imaging is continuously performed while moving the X-ray line sensor in a direction parallel to the conveying direction; and a positioning unit which aligns a position of the optical axis of the X-rays with a position of the X-ray line sensor in the direction parallel to the conveying direction on the basis of the X-ray image acquired in the imaging mode.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an X-ray inspection apparatus. [Background technology]

[0002] Patent Document 1 discloses an X-ray inspection device that irradiates X-rays onto objects to be inspected that are transported sequentially in an inspection space along the transport path and detects the X-rays that have passed through the objects to be inspected, and that includes an X-ray generator arranged at a predetermined height above the inspection space along the transport path, and an X-ray line sensor as an X-ray detector arranged opposite the X-ray generator within the transport section. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7060446 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the X-ray inspection device described in Patent Document 1, for example, when inspecting an object having an internal layer structure separated by partition members so as to form multiple layers, if the position of the X-ray line sensor is misaligned with the position of the optical axis of the X-rays, it may not be possible to accurately capture images of the spaces between the partition members, and it may not be possible to accurately inspect the inside of the object.

[0005] Therefore, when inspecting an object having a layer structure inside, it is important to align the position of the optical axis of the X-ray with the position of the X-ray line sensor.

[0006] However, in the X-ray inspection device described in Patent Document 1, no consideration is given to aligning the position of the optical axis of the X-rays with the position of the X-ray line sensor.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide an X-ray inspection apparatus capable of aligning the position of the optical axis of X-rays with the position of an X-ray line sensor.

Means for Solving the Problems

[0008] The X-ray inspection apparatus according to the present invention includes an X-ray generator that irradiates an object to be inspected with X-rays, and an X-ray line sensor that detects the X-rays transmitted through the object to be inspected. The X-ray inspection apparatus irradiates the object to be inspected that is sequentially conveyed with X-rays, and has an inspection mode for inspecting the object to be inspected using an X-ray image obtained by the X-rays detected by the X-ray line sensor after passing through the object to be inspected. The X-ray inspection apparatus includes a moving mechanism that reciprocally moves the X-ray line sensor in a direction parallel to the conveyance direction of the object to be inspected, and an imaging mode execution unit that can execute an imaging mode in which the object to be inspected stopped at an inspection position through which the optical axis of the X-rays passes is irradiated with the X-rays and continuously imaged while moving the X-ray line sensor in a direction parallel to the conveyance direction, and a positioning unit that aligns the position of the optical axis of the X-rays and the position of the X-ray line sensor in a direction parallel to the conveyance direction based on the X-ray image obtained in the imaging mode.

[0009] With this configuration, in the imaging mode, the X-ray inspection apparatus according to the present invention irradiates the object to be inspected stopped at the inspection position through which the optical axis of the X-rays irradiated from the X-ray generator passes with X-rays and continuously images while moving the X-ray line sensor in a direction parallel to the conveyance direction. Therefore, an X-ray image capable of specifying the position of the optical axis of the X-rays can be obtained by the continuous imaging. Here, the term "stopped" includes not only the case where the object to be inspected that has been moving by conveyance stops, but also the case where the user places it at the inspection position.

[0010] Furthermore, the X-ray inspection device according to the present invention is provided with a positioning unit that aligns the position of the X-ray optical axis in a direction parallel to the conveying direction with the position of the X-ray line sensor based on the X-ray image acquired in the imaging mode, and therefore the position of the X-ray line sensor can be aligned with the position of the X-ray optical axis identified based on the X-ray image acquired in the imaging mode.

[0011] Furthermore, in the X-ray inspection device according to the present invention, it is preferable that the positioning unit detects the position of the optical axis of the X-ray in a direction parallel to the conveying direction based on the X-ray image obtained in the imaging mode, and moves the X-ray line sensor so that the light receiving surface of the X-ray line sensor overlaps with the detected position of the optical axis of the X-ray.

[0012] With this configuration, the X-ray inspection device of the present invention detects the position of the X-ray optical axis in a direction parallel to the conveying direction based on the X-ray image obtained in the imaging mode, and moves the X-ray line sensor so that the light receiving surface of the X-ray line sensor overlaps the position of the detected X-ray optical axis, thereby automatically aligning the position of the X-ray line sensor with the position of the X-ray optical axis.

[0013] Furthermore, in the X-ray inspection apparatus according to the present invention, it is preferable that the positioning unit obtains a representative value for each pixel row aligned in a direction parallel to the transport direction within the X-ray image obtained in the imaging mode, and detects the position of the optical axis of the X-ray based on a distribution of the representative values for each pixel row.

[0014] With this configuration, the X-ray inspection device of the present invention calculates a representative value for each pixel row aligned in a direction parallel to the conveying direction within the X-ray image obtained in the imaging mode, and detects the position of the X-ray optical axis based on the distribution of the representative values for each pixel row, so that the position of the X-ray optical axis can be automatically detected from the X-ray image obtained in the imaging mode.

[0015] Further, the X-ray inspection apparatus according to the present invention preferably further includes a display unit that displays an X-ray image obtained in the imaging mode, and an operation input unit that receives an operation for adjusting the position of the X-ray line sensor in a direction parallel to the conveyance direction.

[0016] With this configuration, since the X-ray inspection apparatus according to the present invention further includes a display unit that displays an X-ray image obtained in the imaging mode, and an operation input unit that receives an operation for adjusting the position of the X-ray line sensor in a direction parallel to the conveyance direction, the X-ray image obtained in the imaging mode can be visually recognized by the user. As a result, the user can perform an operation of adjusting the position of the X-ray line sensor based on the X-ray image displayed on the display unit. For example, the user can specify the position of the optical axis of the X-ray based on the X-ray image displayed on the display unit, and perform an operation of moving the X-ray line sensor to the specified position of the optical axis of the X-ray. Further, in the case of a configuration in which the position of the optical axis of the X-ray and the position of the X-ray line sensor are automatically adjusted, the user can perform an operation of adjusting the position of the X-ray line sensor after the automatic adjustment.

Effects of the Invention

[0017] According to the present invention, it is possible to provide an X-ray inspection apparatus capable of aligning the position of the optical axis of the X-ray and the position of the X-ray line sensor.

Brief Description of the Drawings

[0018]

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DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an X-ray inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0020] (Configuration of X-ray inspection equipment) As shown in Figure 1, the X-ray inspection device 1 of this embodiment is an X-ray inspection device that irradiates X-rays onto inspection objects W that are transported sequentially, detects the X-rays that have passed through the inspection objects W, and uses the resulting X-ray images to inspect the inspection objects W for the presence or absence of foreign matter and the shape of the objects.

[0021] The inspection object W inspected by the X-ray inspection apparatus 1 of this embodiment is an inspection object that has a partition member inside that forms a gap that connects the end of the inspection object on the X-ray generator side to the end on the X-ray line sensor side. In this embodiment, an example will be described in which the inspection object W is a lithium ion secondary battery that has multiple layers formed inside with multiple electrodes as partition members.

[0022] The object W to be inspected may be an object having an internal layer structure such as a lithium ion secondary battery, or may be an object having a cross-sectional shape such as a lotus root shape, honeycomb shape, or lattice shape, in which gaps are formed by multiple partition members that connect the end on the X-ray generator side to the end on the X-ray line sensor side.

[0023] The X-ray inspection apparatus 1 of this embodiment includes a housing (not shown), an X-ray generator 2 that generates X-rays, an X-ray line sensor 3 that detects X-rays that have passed through an inspection object W, a control device 4, and a transport unit 5. The X-ray generator 2, the X-ray line sensor 3, the control device 4, and the transport unit 5 are housed in a housing (not shown).

[0024] The transport unit 5 transports the inspection object W sequentially at predetermined intervals. The transport unit 5 is configured, for example, by a belt conveyor arranged horizontally inside the housing. The transport unit 5 transports the inspection object W, which has been carried in from the inlet of the X-ray inspection apparatus 1, toward the outlet (to the right in FIG. 1) at a predetermined transport speed driven by a drive motor (not shown).

[0025] Here, the object under inspection W is conveyed by the conveyance unit 5 in a posture such that the plane of each flat electrode intersects the conveyance direction of the object under inspection W (right direction in the figure) and is parallel to the direction of the optical axis of the X-ray (indicated by the dotted arrow in FIG. 1). Preferably, the object under inspection W is conveyed by the conveyance unit 5 in a posture such that the plane of each electrode is orthogonal to the conveyance direction.

[0026] The X-ray generator 2 and the X-ray line sensor 3 are arranged so as to face each other in the vertical direction of the conveyance unit 5 with the conveyance path through which the object under inspection W on the conveyance unit 5 passes interposed therebetween.

[0027] The X-ray generator 2 generates X-rays by irradiating the target of the anode with an electron beam from the cathode of the X-ray tube 22 provided therein, and irradiates the object under inspection W located below the X-ray generator 2, as shown by the dashed-dotted line in FIG. 1, with X-rays radially. The X-rays are irradiated radially not only in the direction parallel to the conveyance direction but also in the width direction (the direction orthogonal to the paper surface in FIG. 1) orthogonal to the conveyance direction, as shown by the dashed-dotted line in FIG. 1. Thereby, the X-ray generator 2 irradiates the object under inspection W on the conveyance unit 5 being sequentially conveyed with X-rays.

[0028] In FIG. 1, the optical axis OA indicated by the dotted arrow is the optical axis of the X-rays irradiated by the X-ray generator 2, and in the present embodiment, it means the optical path of the X-rays that can be transmitted with almost no influence from the object under inspection W when the X-rays are irradiated on the object under inspection W.

[0029] The X-ray line sensor 3 includes a plurality of X-ray detection elements (not shown) each including a photodiode (not shown) and a scintillator provided on the photodiode. The X-ray line sensor 3 has the X-ray detection elements arranged linearly in a direction orthogonal to the conveyance direction, and the light receiving surface 31 is disposed on the surface facing the X-ray generator 2, that is, the upper surface.

[0030] The X-ray line sensor 3 detects the X-rays that are irradiated onto the inspection object W from the X-ray generator 2 and that have passed through the inspection object W, and obtains a linear X-ray image in the width direction perpendicular to the transport direction of the inspection object W. Specifically, the X-ray line sensor 3 converts the X-rays into optical signals using a scintillator in the X-ray detection element, and then converts the optical signals into electrical signals using a photodiode. The X-ray line sensor 3 then performs further processing such as noise removal, and generates an X-ray image with a grayscale distribution based on the amount of transmitted X-rays.

[0031] In this embodiment, the X-ray line sensor 3 is configured to be able to move back and forth in a direction parallel to the transport direction by a movement mechanism 8.

[0032] The movement mechanism 8 is configured by an electric actuator, and has a slider 81 , a base 82 , and a motor 83 .

[0033] The slider 81 moves back and forth on the base 82 in a direction parallel to the transport direction, and supports the X-ray line sensor 3 on its upper part. The base 82 has a linear guide (not shown) attached to the slider 81, and a ball screw for linearly moving the linear guide. The motor 83 is composed of a thermomotor or a pulse motor, and rotates the ball screw.

[0034] The movement mechanism 8 reciprocates the X-ray line sensor 3 supported by the slider 81 in a direction parallel to the transport direction by controlling the drive of the motor 83 by the control device 4. Furthermore, the movement mechanism 8 can position and stop the X-ray line sensor 3 at a specific position by controlling the drive amount of the motor 83 based on instructions from the control device 4.

[0035] The moving mechanism 8 of this embodiment is an example and is not limited to this, and any actuator may be used as long as it is capable of moving the X-ray line sensor 3 back and forth in a direction parallel to the transport direction and is configured to control the amount of movement.

[0036] The control device 4 is connected to a display unit 6 and an operation input unit 7.

[0037] The display unit 6 is composed of a flat panel display or the like, and is configured to perform display output to the user. The display unit 6 is configured to display an image such as an inspection result by the control device 4.

[0038] For example, the display unit 6 may display the pass / fail determination result of the object under inspection W with characters or symbols such as "OK" or "NG", or may be configured to display statistical values such as the total number of inspections, the number of good products, and the total number of NGs.

[0039] Furthermore, the display unit 6 is configured to display an X-ray image obtained in the imaging mode described later.

[0040] The display content and display mode of the display unit 6 are determined based on the default settings or requests based on predetermined key operations from the operation input unit 7.

[0041] The operation input unit 7, for example, accepts setting inputs of various parameters and the like from the user to the control device 4, accepts selection of the operation mode of the X-ray inspection device 1, and accepts operations such as adjusting the position of the X-ray line sensor 3 in a direction parallel to the conveyance direction.

[0042] In the present embodiment, the operation input unit 7 is composed of a plurality of keys, switches, etc. operated by the user. For example, the display unit 6 and the operation input unit 7 are integrated as a touch panel display and are arranged at the upper front part of a housing (not shown). Note that the touch panel display is an example of the form of the operation input unit 7 and is not limited thereto, and the arrangement of the operation input unit 7 is not limited to the upper front part of the housing.

[0043] The control device 4 includes an X-ray image storage unit 41, an image processing unit 42, a determination unit 43, a control unit 44, an imaging mode execution unit 45, and a positioning unit 46.

[0044] The X-ray image storage unit 41 stores the X-ray image received from the X-ray line sensor 3 .

[0045] The image processing unit 42 applies various image processing algorithms to the X-ray image read from the X-ray image storage unit 41 to perform image processing. Here, the image processing algorithm is a combination of multiple image processing filters.

[0046] The judgment unit 43 judges whether the object W is good or bad by determining whether there is any electrode stacking misalignment, winding misalignment, short circuit, or foreign matter mixed into the separator in the X-ray image processed by the image processing unit 42.

[0047] The control unit 44 has a CPU and a memory as a storage area or work area for control programs, and is configured to control the entire X-ray inspection apparatus 1. The control contents of the control unit 44 include control of the display content and display form of the display unit 6, as well as control of switching the operation mode in response to a request to switch the operation mode of the X-ray inspection apparatus 1 input via the operation input unit 7.

[0048] In this embodiment, the X-ray inspection apparatus 1 has at least an inspection mode and an imaging mode as operation modes.

[0049] The inspection mode is an operating mode in which X-rays are irradiated onto the objects W to be inspected as they are transported sequentially, and the objects W are inspected using X-ray images obtained by X-rays that pass through the objects W and are detected by the X-ray line sensor 3.

[0050] The imaging mode is an operating mode for obtaining an X-ray image in which the position of the X-ray optical axis OA can be identified. Specifically, as shown in Figure 2, this is an operating mode in which X-rays are irradiated onto the object to be inspected W stopped at the inspection position P through which the X-ray optical axis OA passes, and images are continuously taken while the X-ray line sensor 3 is moved in a direction parallel to the transport direction.

[0051] As the inspection object W used in the imaging mode, for example, an inspection object of a good product sample or an inspection object determined to be a good product in a previous pass / fail determination can be used.

[0052] In the imaging mode, the inspection object W may be placed at the inspection position P by the user, or the inspection object W may be stopped at the inspection position P by the conveyance of the conveyance unit 5.

[0053] When the imaging mode is selected, the imaging mode execution unit 45 irradiates the inspection object W stopped at the inspection position P with X-rays, and continuously detects the X-rays transmitted through the inspection object W while moving the X-ray line sensor 3 in a direction parallel to the conveyance direction. Thereby, an X-ray image Im1 as shown in FIG. 3 is obtained.

[0054] As shown in FIG. 1, based on the X-ray image Im1 (see FIG. 3) acquired in the imaging mode, the positioning unit 46 aligns the optical axis OA of the X-rays and the position of the X-ray line sensor 3 in a direction parallel to the conveyance direction. The detailed operation of the positioning unit 46 will be described later.

[0055] (X-ray image obtained in the imaging mode) As shown in FIG. 3, the X-ray image Im1 acquired in the imaging mode shows an image of the main part of the inspection object W, and is an image in which images Im_e of a plurality of electrodes are arranged in a direction parallel to the conveyance direction (the left-right direction in FIG. 3).

[0056] In the X-ray image Im1, the image Im_e of each electrode is an image in an inclined state corresponding to the position of the X-ray line sensor 3. Also, the inclination direction of the image Im_e of each electrode is reversed with the optical axis position Loa indicating the position of the optical axis OA of the X-rays as a boundary. Furthermore, the farther the image Im_e of the electrode is from the optical axis position Loa, the greater the inclination.

[0057] In FIG. 3, the optical axis position Loa is shown as a virtual line extending in the width direction orthogonal to the conveyance direction and passing through the optical axis OA of the X-ray. The optical axis position Loa is a virtual line indicating the position of the optical axis OA of the X-ray, which is physically determined from the positional relationship among the object to be inspected W, the X-ray generator 2, and the X-ray line sensor 3.

[0058] In the present embodiment, the position of the optical axis OA of the X-ray is detected from this X-ray image Im1. The detection of the position of the optical axis OA of the X-ray is performed by the positioning unit 46.

[0059] (Operation of the positioning unit) Next, the operation of the positioning unit 46 will be described.

[0060] As shown in FIG. 4, the positioning unit 46 detects the position of the optical axis OA of the X-ray in the direction parallel to the conveyance direction based on the X-ray image Im1, and moves the X-ray line sensor 3 so that the light-receiving surface 31 of the X-ray line sensor 3 overlaps the detected position of the optical axis OA of the X-ray.

[0061] Here, an example of the method for detecting the position of the optical axis OA of the X-ray will be described. The positioning unit 46 obtains, for each pixel column arranged in the direction parallel to the conveyance direction in the X-ray image Im1 obtained in the imaging mode, the number of pixels having specific image information in the width direction orthogonal to the conveyance direction as the representative value of the pixel column, and detects the position of the optical axis OA of the X-ray based on the distribution of the representative values of the respective pixel columns.

[0062] More specifically, as shown in FIG. 5, the positioning unit 46 obtains, for each of the above-described pixel columns in the X-ray image Im1, the total value of the pixels indicating the image information of the electrode, for example, the pixels having a pixel value equal to or less than a predetermined value, as the representative value, and graphs the representative values as shown by the dotted line in FIG. 5.

[0063] Note that the above-described graphing method is just an example and is not limited thereto. For example, the sum of pixel values for each pixel column may be used as a representative value for graphing, or after performing binarization processing on the X-ray image Im1, the total value of the number of pixels indicating pixel value "0" for each pixel column may be used as a representative value for graphing. Also, for each pixel column, the sum of the luminance values of the pixels constituting each pixel column or the average value of those luminance values may be obtained as a representative value, and these sum values or average values of luminance values may be used as representative values for graphing. Thus, as long as the characteristics for each pixel column can be graphed, any method may be used for the above-described graphing.

[0064] Then, for each graphed representative value, a process of replacing it with a simplified graph S such that, for example, it is "0" when less than a predetermined threshold TH and "1" when equal to or greater than the predetermined threshold TH is performed. Note that when graphing using the sum of pixel values for each pixel column as a representative value as described above, another threshold different from the predetermined threshold TH is used, and it is "1" when less than the other threshold and "0" when equal to or greater than the other threshold.

[0065] Next, as shown in FIG. 6, the positioning unit 46 obtains the center of the smallest width Sw1 of the width Ws of the region indicating "1" in the graph S and the center of the second smallest width Sw2, and calculates the position that equally divides the middle between those centers, that is, the position between the center of width Sw1 and the center of width Sw2 at equal intervals, as the position of the optical axis OA of the X-ray. Hereinafter, the position of the optical axis OA of the X-ray calculated from the graph S is referred to as the "calculated optical axis position Lc". For example, the positioning unit 46 calculates the pixel column located at the position that equally divides the middle between the center of width Sw1 and the center of width Sw2 as the calculated optical axis position Pc of the X-ray.

[0066] Here, the position information of each pixel column arranged in the direction parallel to the conveyance direction in the X-ray image Im1 is stored in the X-ray image storage unit 41 in association with the movement amount of the X-ray line sensor 3. As the movement amount of the X-ray line sensor 3, for example, the movement amount from the initial position where the X-ray line sensor 3 is located closest to the motor 83 side is used.

[0067] In the direction parallel to the conveyance direction, if the amount of movement when the X-ray line sensor 3 starts imaging and the amount of movement when the imaging ends are known, the position information of each pixel column can be associated with the amount of movement of the X-ray line sensor 3.

[0068] The positioning unit 46 obtains the amount of movement of the X-ray line sensor 3 from the calculated optical axis position Lc of the X-ray calculated as described above, and moves the X-ray line sensor 3 by the amount of movement. As a result, the light receiving surface 31 of the X-ray line sensor 3 overlaps the position of the optical axis OA of the X-ray, and the position of the optical axis OA of the X-ray and the position of the X-ray line sensor 3 match.

[0069] In the present embodiment, the inspection mode is executed in a state where the position of the optical axis OA of the X-ray and the position of the X-ray line sensor 3 are aligned by the positioning unit 46. Therefore, it is preferable that the imaging mode and the positioning of the X-ray line sensor 3 by the positioning unit 46 are performed before the execution of the inspection mode.

[0070] (Relationship between the position of the X-ray line sensor and the X-ray image obtained in the inspection mode) Next, with reference to FIGS. 7 to 15, the relationship between the position of the X-ray line sensor 3 and the X-ray image Im2 obtained in the inspection mode will be described.

[0071] As shown in FIG. 7, when the X-ray line sensor 3 is located at the X-ray line sensor position C1, that is, when the X-ray line sensor 3 is slightly deviated from the position of the optical axis OA of the X-ray, the X-ray image Im2 obtained in the inspection mode is an image as shown in FIG. 8. The X-ray line sensor position C1 shows a case where, as shown in FIG. 2, the light receiving surface 31 of the X-ray line sensor 3 does not overlap the position of the optical axis OA of the X-ray, but is adjacent to the optical axis OA of the X-ray.

[0072] In this case, since imaging is performed from a position slightly deviated in the direction parallel to the conveyance direction with respect to each electrode of the object to be inspected W, as shown in FIG. 8, the image Im_e of each electrode in the X-ray image Im2 is an image slightly inclined in the direction parallel to the conveyance direction.

[0073] As shown in FIG. 9, when the X-ray line sensor 3 is located at the X-ray line sensor position C2, that is, when the X-ray line sensor 3 is farther from the position of the optical axis OA of the X-ray than the X-ray line sensor position C1, the X-ray image Im2 obtained in the inspection mode becomes an image as shown in FIG. 10. The X-ray line sensor position C2 indicates a case where the light receiving surface 31 of the X-ray line sensor 3 is located at a position farther from the position of the optical axis OA of the X-ray than the X-ray line sensor position C1, as shown in FIG. 2.

[0074] In this case, since the imaging is performed from a position shifted in a direction parallel to the conveyance direction with respect to each electrode of the object to be inspected W more than when the X-ray line sensor 3 is located at the X-ray line sensor position C1, as shown in FIG. 10, in the X-ray image Im2, the image Im_e of each electrode is an image that is more greatly inclined in the direction parallel to the conveyance direction than the image Im_e of each electrode shown in FIG. 8.

[0075] As shown in FIG. 11, when the X-ray line sensor 3 is located at the X-ray line sensor position C3, that is, when the X-ray line sensor 3 is farther from the position of the optical axis OA of the X-ray than the X-ray line sensor position C2, the X-ray image Im2 obtained in the inspection mode becomes an image as shown in FIG. 12. The X-ray line sensor position C3 indicates a case where the light receiving surface 31 of the X-ray line sensor 3 is located at a position farther from the position of the optical axis OA of the X-ray than the X-ray line sensor position C2, as shown in FIG. 2.

[0076] In this case, since the imaging is performed from a position shifted in a direction parallel to the conveyance direction with respect to each electrode of the object to be inspected W more than when the X-ray line sensor 3 is located at the X-ray line sensor position C2, as shown in FIG. 12, in the X-ray image Im2, the image Im_e of each electrode is an image that is more greatly inclined in the direction parallel to the conveyance direction than the image Im_e of each electrode shown in FIG. 10. Further, in the X-ray image Im2 shown in FIG. 12, the gap between the images Im_e of each electrode also becomes smaller.

[0077] As shown in FIG. 13, when the X-ray line sensor 3 is located at the X-ray line sensor position C4, that is, when the X-ray line sensor 3 is farther from the position of the optical axis OA of the X-ray than the X-ray line sensor position C3, the X-ray image Im2 obtained in the inspection mode becomes an image as shown in FIG. 14. The X-ray line sensor position C4 indicates a case where the light receiving surface 31 of the X-ray line sensor 3 is at a position farther from the position of the optical axis OA of the X-ray than the X-ray line sensor position C3, as shown in FIG. 2.

[0078] In this case, since the X-ray line sensor 3 images from a position shifted in a direction parallel to the transport direction with respect to each electrode of the object to be inspected W more than when the X-ray line sensor 3 is located at the X-ray line sensor position C3, as shown in FIG. 14, in the X-ray image Im2, the images Im_e of the respective electrodes are more inclined in the direction parallel to the transport direction than the images Im_e of the respective electrodes shown in FIG. 12. Furthermore, in the X-ray image Im2 shown in FIG. 14, the images Im_e of the respective electrodes are in an overlapping state.

[0079] Thus, when the inspection mode is performed when the X-ray line sensor 3 is located at the X-ray line sensor positions C1 to C4, the inspection region between the electrodes of the object to be inspected W becomes difficult to identify due to the images Im_e of the respective electrodes inclined in the direction parallel to the transport direction, and there is a possibility that the inside of the object to be inspected W cannot be accurately inspected.

[0080] On the other hand, in the present embodiment, since the inspection mode is executed in a state where the position of the optical axis OA of the X-ray and the position of the X-ray line sensor 3 are aligned by the positioning unit 46, the X-ray image Im2 obtained in the inspection mode becomes an image as shown in FIG. 15.

[0081] As shown in FIG. 15, the X-ray image Im2 obtained in the inspection mode of the present embodiment does not become an image in which the images Im_e of the respective electrodes are inclined, and becomes an image in which the inspection region between the electrodes of the object to be inspected W is easily distinguishable.

[0082] (Function and effect) As described above, in the imaging mode, the X-ray inspection apparatus according to the present embodiment irradiates an X-ray to an object to be inspected W that is stopped at an inspection position P through which the optical axis OA of the X-ray irradiated from the X-ray generator 2 passes, and continuously performs imaging while moving the X-ray line sensor 3 in a direction parallel to the conveyance direction. Therefore, an X-ray image IM1 capable of specifying the position of the optical axis OA of the X-ray can be obtained by the continuous imaging.

[0083] Further, the X-ray inspection apparatus according to the present embodiment includes a positioning unit 46 that aligns the position of the optical axis OA of the X-ray in a direction parallel to the conveyance direction and the position of the X-ray line sensor 3 based on the X-ray image IM1 obtained in the imaging mode. Therefore, the position of the X-ray line sensor 3 can be aligned with the position of the optical axis OA of the X-ray specified based on the X-ray image IM1 obtained in the imaging mode.

[0084] Further, the X-ray inspection apparatus according to the present embodiment calculates a calculated optical axis position Lc based on the X-ray image IM1 obtained in the imaging mode, detects the calculated optical axis position Lc as the position of the optical axis OA of the X-ray in a direction parallel to the conveyance direction, and moves the X-ray line sensor 3 so that the light receiving surface 31 of the X-ray line sensor 3 overlaps the detected position of the optical axis OA of the X-ray. Therefore, the position of the X-ray line sensor 3 can be automatically aligned with the position of the optical axis OA of the X-ray.

[0085] Further, the X-ray inspection apparatus according to the present embodiment obtains, for each pixel column arranged in a direction parallel to the conveyance direction within the X-ray image IM1 obtained in the imaging mode, the number of pixels having specific image information in a direction orthogonal to the conveyance direction as a representative value of the pixel column, and calculates the calculated optical axis position Lc based on the distribution of the representative values of the respective pixel columns. Therefore, the position of the optical axis OA of the X-ray can be automatically detected from the X-ray image IM1 obtained in the imaging mode.

[0086] In addition, the X-ray inspection device of this embodiment further includes a display unit 6 that displays the X-ray image IM1 obtained in the imaging mode, and an operation input unit 7 that accepts operations to adjust the position of the X-ray line sensor 3 in a direction parallel to the conveying direction, so that the user can view the X-ray image IM1 obtained in the imaging mode.

[0087] This allows the user to adjust the automatically adjusted position of the X-ray line sensor 3 based on the X-ray image IM1 displayed on the display unit 6. For example, as shown in FIG. 6, if there is a misalignment between the calculated optical axis position Lc calculated from the graph S and the optical axis position Loa, which indicates the position of the X-ray optical axis OA physically determined based on the positional relationship between the object W, the X-ray generator 2, and the X-ray line sensor 3, and this affects the inspection in the inspection mode, the user can manually adjust, for example, the calculated optical axis position Lc. In this case, the optical axis position Loa is displayed within the X-ray image IM1. The optical axis position Loa is, for example, the position of the X-ray optical axis OA visually identified by the user based on the X-ray image IM1 displayed on the display unit 6 and is input by the user via the operation input unit 7. The optical axis position Loa may be displayed so as to be movable left and right within the X-ray image IM1, for example, by the user's cursor operation. In this case, the user can specify the position of the optical axis position Loa by cursor operation.

[0088] Furthermore, a configuration may be adopted in which the amount of deviation between the X-calculated optical axis position Lc and the optical axis position Loa is calculated without manual operation by the user, and correction according to the amount of deviation is automatically performed.

[0089] (Variation) In the present embodiment, a configuration for automatically detecting the optical axis OA of X-rays has been described. However, the present invention is not limited to this, and the optical axis OA of X-rays may be specified visually by the user based on the X-ray image IM1 displayed on the display unit 6. In this case, the user specifies the optical axis OA of X-rays in the X-ray image IM1, and inputs, via the operation input unit 7, the amount of movement of the X-ray line sensor 3 such that the position of the X-ray line sensor 3 matches the position of the specified optical axis OA of X-rays. Thereby, the positioning unit 46 moves the X-ray line sensor 3 based on the amount of movement of the X-ray line sensor 3 input via the operation input unit 7.

[0090] In the present embodiment, an example in which the X-ray image IM1 is displayed on the display unit 6 has been described. However, the present invention is not limited to this, and for example, a graph S may be displayed instead of the X-ray image IM1, or these may be displayed simultaneously.

[0091] Further, in the present embodiment, an example in which representative values obtained for each pixel column arranged in a direction parallel to the conveyance direction in the X-ray image Im1 obtained in the imaging mode are graphed, and the position of the optical axis OA of X-rays is detected based on the graph has been described. However, the present invention is not limited to this, and for example, while imaging is performed while moving the X-ray line sensor 3 in the imaging mode, the representative value of each pixel column is calculated for each pixel column, and the position of the optical axis OA of X-rays may be detected based on the change in the representative value of each pixel column accompanying the movement of the X-ray line sensor 3.

[0092] In the present embodiment, an example in which the X-ray inspection apparatus according to the present invention is applied to an X-ray inspection apparatus of a type that irradiates X-rays downward has been described. However, the present invention is not limited to this, and for example, it may be applied to an X-ray inspection apparatus of a type that irradiates X-rays upward.

[0093] Furthermore, in this embodiment, an example has been described in which the X-ray inspection apparatus according to the present invention is applied to an X-ray inspection apparatus of a type in which the X-ray generator 2 and the X-ray line sensor 3 are arranged so as to face each other in the vertical direction across the transport path of the object W to be inspected. However, the present invention is not limited to this, and may also be applied to, for example, a horizontal irradiation type X-ray inspection apparatus in which the X-ray generator 2 and the X-ray line sensor 3 are arranged so as to face each other in the width direction perpendicular to the transport direction of the object W to be inspected across the transport path of the object W to be inspected.

[0094] While an embodiment of the present invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made thereto without departing from the scope of the present invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0095] 1 X-ray inspection equipment 2 X-ray generators 3 X-ray line sensor 4. Control device 5. Conveyor 6 Display section 7 Operation input section 8 Moving mechanism 31 Photosensitive surface 41 X-ray image storage unit 42 Image processing section 43 Judgment section 44 Control Unit 45 Imaging mode execution unit 46 Positioning part 81 Slider 82 base 83 Motor W Inspection object OA X-ray optical axis P Inspection position Im1, Im2 X-ray image Im_e Electrode image C1, C2, C3, C4 X-ray line sensor positions

Claims

1. An X-ray generator (2) that irradiates an object to be inspected (W) with X-rays, an X-ray line sensor (3) that detects the X-rays that have passed through the object to be inspected, and an X-ray inspection apparatus having an inspection mode in which the object to be inspected being sequentially conveyed is irradiated with X-rays, and the object to be inspected is inspected using an X-ray image obtained by the X-rays that have passed through the object to be inspected and detected by the X-ray line sensor, a moving mechanism (8) that reciprocally moves the X-ray line sensor in a direction parallel to the conveyance direction of the object to be inspected, an imaging mode execution unit (45) that irradiates the object to be inspected stopped at an inspection position (P) through which the optical axis of the X-rays passes with the X-rays and continuously performs imaging while moving the X-ray line sensor in a direction parallel to the conveyance direction, an X-ray inspection apparatus comprising a positioning unit (46) that aligns the position of the optical axis of the X-rays and the position of the X-ray line sensor in a direction parallel to the conveyance direction based on the X-ray image obtained in the imaging mode.

2. The X-ray inspection apparatus according to claim 1, wherein the positioning unit detects the position of the optical axis of the X-rays in a direction parallel to the conveyance direction based on the X-ray image obtained in the imaging mode, and moves the X-ray line sensor so that the light receiving surface (31) of the X-ray line sensor overlaps the detected position of the optical axis of the X-rays.

3. The X-ray inspection apparatus according to claim 2, wherein the positioning unit obtains a representative value of each pixel column for each pixel column arranged in a direction parallel to the conveyance direction in the X-ray image obtained in the imaging mode, and detects the position of the optical axis of the X-rays based on the distribution of the representative values of the pixel columns.

4. a display unit (6) that displays the X-ray image obtained in the imaging mode, and an operation input unit (7) that receives an operation for adjusting the position of the X-ray line sensor in a direction parallel to the conveyance direction, and further comprising the X-ray inspection apparatus according to any one of claims 1 to 3.

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