X-ray transmission inspection apparatus and X-ray transmission inspection method

Abstract

The present invention provides a transmission X-ray inspecting device having improved detection sensitivity with respect to foreign matter in a specimen, the transmission X-ray inspecting device comprising: an X-ray source 2 for emitting X-rays including a plurality of mutually different energy ranges; an optical element 3 for dispersing X-rays in one energy range from the X-rays, and condensing the same toward a specimen W; and a transmitted X-ray detector 4 for detecting transmitted X-rays that have been transmitted through the specimen W.

Description

Technical Field

[0001] The present invention relates to a transmission X-ray inspection apparatus and a transmission X-ray inspection method.

Background Art

[0002] Conventionally, as a system for inspecting foreign substances in a sample, there is one that uses a transmission X-ray inspection apparatus as shown in Patent Document 1. This transmission X-ray inspection apparatus irradiates X-rays from an X-ray generator onto a sample, detects the transmitted X-rays that have passed through the sample, and inspects for foreign substances.

[0003] However, since the X-rays from the X-ray generator are irradiated onto the sample while spreading, the intensity of the X-rays irradiated onto the sample is weak. As a result, the intensity of the transmitted X-rays that pass through the sample also becomes weak. Therefore, the detection sensitivity of the transmission X-ray detector decreases. In order to improve the detection sensitivity of the transmission X-ray detector, it is conceivable to increase the integration dose by increasing the counting time, but the time for inspecting for foreign substances for each sample becomes long.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the present invention has been made in view of the above-described problems, and its main problem is to improve the detection sensitivity of foreign substances in a sample in a transmission X-ray inspection apparatus.

Means for Solving the Problems

[0006] In other words, the transmission X-ray inspection apparatus according to the present invention is characterized by comprising an X-ray source that emits X-rays including multiple energy ranges that are different from each other, an optical element that spectrally separates the X-rays into X-rays of one energy range and focuses them toward a sample, and a transmission X-ray detection unit that detects the transmission X-rays that have passed through the sample.

[0007] With this configuration, X-rays containing multiple different energy ranges are spectrally separated into X-rays of a single energy range and focused toward the sample. This improves the intensity of the X-rays in that single energy range irradiated onto the sample, thereby increasing the contrast of the transmitted X-rays. As a result, the detection sensitivity of foreign matter in the sample can be improved in the transmitted X-ray inspection device. Furthermore, by improving the intensity of the X-rays in that single energy range irradiated onto the sample, the time required for foreign matter inspection of each sample can be shortened. In this invention, foreign matter in the sample includes foreign matter adhering to the sample surface and foreign matter contained within the sample.

[0008] In order to efficiently inspect the sample being transported by the transport mechanism, it is desirable that the optical element be a curved spectrometer that focuses X-rays in one energy range in a line shape.

[0009] Furthermore, it is desirable that the transmitted X-ray detection unit be a line sensor provided in accordance with the line-shaped focused X-rays. In order to detect all X-rays irradiated onto the sample without omission and improve detection accuracy, it is desirable that the pixel width of the line sensor be approximately the same as the width of the line-shaped focused X-rays.

[0010] Furthermore, the transmission X-ray inspection apparatus of the present invention is used in conjunction with a transport mechanism for transporting the sample, and it is desirable that the optical element and the transmission X-ray detection unit are positioned on either side of the sample being transported by the transport mechanism. Here, it is desirable that the longitudinal direction of the line-shaped focused X-rays and the longitudinal direction of the line sensor be perpendicular to the transport direction of the transport mechanism. With this configuration, in a system where samples are transported by a transport mechanism, the intensity of X-rays in one energy range irradiated onto the transported sample can be improved. As a result, the cumulative dose in the transmitted X-ray detection unit can be increased without increasing the counting time, and the contrast of transmitted X-rays can be increased even when transported at a higher speed than before. Consequently, the inspection of foreign objects in samples can be accelerated.

[0011] To improve the detection sensitivity of the foreign substance to be detected, it is desirable that the optical element spectrally analyzes X-rays in an energy range higher than the X-ray absorption edge of the foreign substance to be detected in the sample. Here, the X-ray absorption edge of the foreign substance is a concept that includes, for example, the K absorption edge, L1 absorption edge, L2 absorption edge, or L3 absorption edge, and the X-ray absorption edge is selected according to the foreign substance, and the optical element is selected accordingly. For example, if the foreign substance is copper, the K absorption edge can be selected.

[0012] To improve the intensity of the X-rays irradiated onto the sample, it is desirable to have two optical elements that spectrally separate the X-rays into X-rays of the same energy range and focus them toward the sample. With this configuration, the cumulative dose of the transmitted X-ray detection unit can be increased without extending the counting time, and the contrast of the transmitted X-rays can be increased even when transported at a higher speed than before. As a result, the accuracy and speed of foreign object inspection of samples can be improved.

[0013] In order to improve the detection sensitivity of one type of foreign object, or to enable the detection of multiple types of foreign objects, it is desirable that the transmission X-ray inspection apparatus of the present invention has multiple types of optical elements, and that these multiple types of optical elements spectrally separate into X-rays in different energy ranges.

[0014] A specific embodiment for improving the detection sensitivity of a single type of foreign substance is to have two types of optical elements, wherein one of the two optical elements spectrally analyzes X-rays in an energy range higher than the X-ray absorption edge of the foreign substance to be detected in the sample, and the other of the two optical elements spectrally analyzes X-rays in an energy range lower than the X-ray absorption edge.

[0015] Here, it is desirable that the multiple types of optical elements spectrally separate the X-rays from a single X-ray source into X-rays in different energy ranges. With this configuration, there is no need to provide multiple X-ray sources corresponding to each of the multiple types of optical elements, and the device can be miniaturized.

[0016] In a configuration that spectrally separates X-rays into different energy ranges using multiple types of optical elements, it is desirable that the transmission X-ray detection unit has multiple transmission X-ray detectors for generating multiple transmission X-ray images corresponding to each of the X-rays in the different energy ranges.

[0017] To improve the accuracy of detecting foreign matter, the transmission X-ray inspection apparatus of the present invention further comprises an image processing unit that processes transmission X-ray images generated using each of the plurality of transmission X-ray detectors, and it is desirable that the image processing unit performs differential processing using the plurality of transmission X-ray images corresponding to each of the X-rays in different energy ranges to detect foreign matter in the sample.

[0018] In order to make the detected foreign object easily visible to the user, the transmission X-ray inspection apparatus of the present invention further comprises a display control unit that displays the transmission X-ray image on a display, and it is desirable that the display control unit displays the foreign object detected by the image processing unit in color.

[0019] As a specific embodiment for inspecting different first and second foreign objects, the optical element includes a first optical element that spectrally separates into first X-rays in an energy range lower than the X-ray absorption edge of the first foreign object, a second optical element that spectrally separates into second X-rays in an energy range higher than the X-ray absorption edge of the first foreign object and lower than the X-ray absorption edge of the second foreign object, and a third optical element that spectrally separates into third X-rays in an energy range higher than the X-ray absorption edge of the second foreign object. The image processing unit preferably performs differential processing using a first transmitted X-ray image obtained by irradiating the first X-rays, a second transmitted X-ray image obtained by irradiating the second X-rays, and a third transmitted X-ray image obtained by irradiating the third X-rays to detect the first and second foreign objects.

[0020] When a plurality of types of optical elements are arranged, the positional relationship with the X-ray source and the transmitted X-ray detection unit is different for each optical element, so the X-ray intensity irradiated on the sample will be different. Therefore, it is desirable that the transmission X-ray inspection apparatus of the present invention further includes a correction unit that corrects the difference in the X-ray intensity irradiated on the sample from each of the plurality of types of optical elements.

[0021] Also, the transmission X-ray inspection method according to the present invention is characterized in that X-rays including a plurality of different energy ranges emitted from an X-ray source are spectrally separated into X-rays of one energy range by an optical element and condensed toward a sample, and the transmitted X-rays transmitted through the sample are detected by a transmitted X-ray detection unit. and others

Advantages of the Invention

[0022] According to the present invention described above, it is possible to improve the detection sensitivity of foreign objects in a sample in a transmission X-ray inspection apparatus.

Brief Description of the Drawings

[0023] [Figure 1] It is a perspective view schematically showing the overall configuration of a transmission X-ray inspection apparatus according to an embodiment of the present invention. [Figure 2] It is a side view schematically showing the overall configuration of the transmission X-ray inspection apparatus in the same embodiment.​ [Figure 3] It is a functional block diagram of the signal processing device in the same embodiment. [Figure 4] It is a graph showing the X-ray absorption edge of the foreign object to be detected in the same embodiment and the energy of the spectroscopically analyzed X-rays. [Figure 5] It is a graph showing the X-ray absorption edges of the first foreign object and the second foreign object and the energy of the spectroscopically analyzed X-rays in the modified embodiment. [Figure 6] It is a diagram showing a configuration in which X-rays from an X-ray source are spectroscopically separated into X-rays in one energy range and irradiated onto a sample W.

Embodiments for Carrying Out the Invention

[0024] Hereinafter, an embodiment of a transmission X-ray inspection apparatus according to the present invention will be described with reference to the drawings. In all the figures shown below, for the sake of clarity, they are schematically drawn with appropriate omissions or exaggerations. The same components are denoted by the same reference numerals and the description thereof will be omitted as appropriate.

[0025] As shown in FIGS. 1 and 2, the transmission X-ray inspection apparatus 100 of the present embodiment includes an X-ray source 2 that emits primary X-rays, an optical element 3 that condenses the primary X-rays while spectroscopically separating them toward a sample W, a transmission X-ray detection unit 4 that detects the transmission X-rays transmitted through the sample W, and a signal processing device 5 that processes the detection signal from the transmission X-ray detection unit 4. [[ID=2�]]

[0026] Furthermore, the X-ray transmission inspection apparatus 100 of this embodiment has a transport mechanism 6 that transports the sample W to be inspected in a predetermined direction (the left-right direction in Figure 2, which is the X direction in this case). The optical element 3 and the X-ray transmission detection unit 4 are positioned to sandwich the sample W being transported by the transport mechanism 6 from above and below. With this configuration, the X-ray transmission inspection apparatus 100 of this embodiment can perform foreign matter inspection of the sample W while the sample W is being transported by the transport mechanism 6. The X-ray transmission inspection apparatus 100 can also be incorporated into an in-line system, for example, by a film coating apparatus 7 that coats a film material onto a substrate. In this embodiment, the sample W is, for example, the positive electrode material of a lithium-ion battery, and the foreign matter S to be detected is copper (K ​​absorption edge energy is 8.98 keV).

[0027] X-ray source 2 emits primary X-rays (multicolor X-rays) that include multiple energy ranges (wavelength ranges) that are different from each other. Specifically, X-ray source 2 is an X-ray tube that generates continuous X-rays and characteristic X-rays by colliding electrons generated by heating a filament with a target metal such as tungsten or molybdenum. In this embodiment, the target metal is tungsten.

[0028] The optical element 3 focuses the primary X-rays onto the sample W while spectrally separating them into X-rays within a single energy range (single wavelength range). Here, the single energy range (single wavelength range) is determined based on the transmittance of the foreign substance S to be detected, particularly the X-ray absorption edge (in this case, the K absorption edge of copper).

[0029] Specifically, optical element 3 is a curved spectrometer that spectrally separates (monochromatizes) X-rays in a single energy range while simultaneously focusing them in a linear shape. Here, the longitudinal direction of the X-rays focused in a linear shape by optical element 3a is perpendicular to the transport direction of the transport mechanism 6 (Y direction). By using this curved spectrometer, the primary X-rays incident with a broad spread can be Bragg-reflected by the curved crystal surface and focused at a predetermined position (in this case, the upper surface of the sample W), thereby extracting only X-rays in a predetermined energy range. Examples of materials for the curved spectrometer include silicon, graphite, lithium fluoride, and other materials used as spectroscopic crystals. When a curved spectrometer is constructed by combining two types of spectroscopic crystals, the wavelength of spectral separation is changed by changing the curvature of the spectroscopic crystal (size of the Rowland circle) to change the wavelength of X-rays focused. Alternatively, the wavelength of spectral separation can also be changed by changing the curvature of the spectroscopic crystal (size of the Rowland circle) and / or the material of the spectroscopic crystal. The optical element 3 of this embodiment is L of tungsten fluorescent X-rays. β (High energy; 9.67~9.96 keV) and L α (Low energy; 8.40 keV) is spectrally separated and focused.

[0030] In this embodiment, as shown in Figures 1 and 2, there are multiple types (two types in this case) of optical elements 3a and 3b that spectrally separate into X-rays in different energy ranges. One of the two types of optical element 3a spectrally separates into high-energy X-rays and focuses them onto the sample W. The other of the two types of optical element 3b spectrally separates into low-energy X-rays and focuses them onto the sample W.

[0031] Here, Figure 4 As shown, the X-rays spectrally separated by one optical element 3a are in an energy range higher than the X-ray absorption edge of the foreign substance S to be detected in the sample W. On the other hand, the X-rays spectrally separated by the other optical element 3b are in an energy range lower than the X-ray absorption edge of the foreign substance S to be detected in the sample W.

[0032] The transmitted X-ray detection unit 4 detects transmitted X-rays that have passed through the sample W, and as shown in Figures 1 and 2, it is configured using transmitted X-ray detectors 4a and 4b, which are line sensors provided on the lower surface side of the sample W. These transmitted X-ray detectors 4a and 4b are provided in accordance with the X-rays focused in a line shape. In other words, the longitudinal direction of the transmitted X-ray detectors 4a and 4b is perpendicular to the transport direction of the transport mechanism 6 (Y direction). Furthermore, the pixel width of the transmitted X-ray detectors 4a and 4b is approximately the same as the width of the X-rays focused in a line shape.

[0033] The transmitted X-ray detection unit 4 of this embodiment has a plurality (in this case, two) of transmitted X-ray detectors 4a and 4b for generating a plurality of transmitted X-ray images corresponding to X-rays in different energy ranges. One transmitted X-ray detector 4a is a line sensor provided in correspondence with one optical element 3a and detects transmitted X-rays from a sample W irradiated with high-energy X-rays. The other transmitted X-ray detector 4b is a line sensor provided in correspondence with the other optical element 3b and detects transmitted X-rays from a sample W irradiated with low-energy X-rays. Each line sensor has a scintillator provided in a line and an X-ray filter provided in front of the X-ray incident side of the scintillator. The X-ray filter transmits the transmitted X-rays to be detected while blocking other X-rays that would be disturbing. The line sensors may also be configured using semiconductor radiation detectors (SDDs) or photomultiplier tubes.

[0034] The signal processing device 5 processes the detection signal from the transmission X-ray detection unit 4 to generate a transmission X-ray image and detect foreign objects from the transmission X-ray image. Specifically, the signal processing device is a computer having a CPU, memory, input / output interface, display 50, input means, etc. (Figure) 3 As shown, it has functions such as an image generation unit 5a, an image processing unit 5b, a foreign object detection unit 5c, and a display control unit 5d.

[0035] The image generation unit 5a acquires detection signals from multiple transmission X-ray detectors 4a and 4b and generates multiple transmission X-ray images. In this embodiment, a high-energy transmission X-ray image is generated using the detection signal from one transmission X-ray detector 4a, and a low-energy transmission X-ray image is generated using the detection signal from the other transmission X-ray detector 4b. The transmission X-ray images generated by the image generation unit 5a are transmitted to the image processing unit 5b and to the display control unit 5d.

[0036] The image processing unit 5b performs difference processing using the high-energy and low-energy transmitted X-ray images generated by the image generation unit 5a to detect foreign matter in the sample W. The image processing unit 5b generates a difference image between the high-energy and low-energy transmitted X-ray images to increase the contrast of the transmitted X-ray image, making it easier to extract the foreign matter S. The difference image generated by the image processing unit 5b is transmitted to the foreign matter detection unit 5c and also to the display control unit 5d.

[0037] The foreign object detection unit 5c detects foreign objects S from the difference image generated by the difference processing of the image processing unit 5b. For example, the foreign object detection unit 5c determines the size of the foreign object from the difference image and detects it as a foreign object if its size is, for example, 20 μm or more in area equivalent diameter. The foreign object information indicating the foreign object detected by the foreign object detection unit 5c is transmitted to the display control unit 5d. The foreign object information is image data in which the foreign object was detected, and this image data is also stored in the memory of the signal processing device 5. The foreign object detection unit 5c can also transmit the image data along with error information indicating that a foreign object has been detected to a server (higher-level control device) in the control room, etc.

[0038] The display control unit 5d displays the foreign object S detected by the foreign object detection unit 5c on the display 50. Specifically, the display control unit 5d overlays the difference image generated by the image processing unit 5b with the detected foreign object and displays them on the display 50. Here, the display control unit 5d can display the detected foreign object in a manner that is easy for the user to see, such as by coloring the detected foreign object.

[0039] In addition, the display control unit 5d can also display the X-ray transmission images for each energy range generated by the image generation unit 5a, or the difference images generated by the image processing unit 5b, on the display 50. Furthermore, the display control unit 5d can also overlay the X-ray transmission images for each energy range generated by the image generation unit 5a with the detected foreign object and display them on the display 50.

[0040] <Effects of this embodiment> According to the X-ray transmission inspection apparatus 100 of this embodiment, configured in this way, X-rays containing multiple different energy ranges are spectrally separated into X-rays of a single energy range and focused toward the sample W. This improves the intensity of the X-rays of a single energy range irradiated onto the sample W, thereby increasing the contrast of the transmitted X-rays. As a result, the detection sensitivity of foreign matter S in the sample W can be improved in the X-ray transmission inspection apparatus 100. Furthermore, by improving the intensity of the X-rays of a single energy range irradiated onto the sample W, the time required for foreign matter inspection of each sample W can be shortened.

[0041] Furthermore, the sample W is transported by a transport mechanism 6 In a system that transports samples, the intensity of X-rays in one energy range irradiated onto the transported sample W can be improved. As a result, the cumulative dose of the transmitted X-ray detection unit 4 can be increased without increasing the counting time, and the contrast of transmitted X-rays can be increased even when transported at a higher speed than before. As a result, the inspection of foreign matter in the sample W can be accelerated.

[0042] <Other Embodiments> For example, in the above embodiment, one type of foreign object was detected, but two or more types of foreign objects may be detected. Specifically, when inspecting a first foreign object and a second foreign object of different types, the optical element 3 includes a first optical element that spectrally analyzes first X-rays (see Figure 5) in an energy range lower than the X-ray absorption edge of the first foreign object, a second optical element that spectrally analyzes second X-rays (see Figure 5) in an energy range higher than the X-ray absorption edge of the first foreign object and lower than the X-ray absorption edge of the second foreign object, and a third optical element that spectrally analyzes third X-rays (see Figure 5) in an energy range higher than the X-ray absorption edge of the second foreign object. The first to third optical elements are curved X-ray spectrometers, as in the above embodiment. In addition, corresponding to these three optical elements, the transmitted X-ray detection unit 4 has three transmitted X-ray detectors.

[0043] Then, the image processing unit 5b performs difference processing using the first transmitted X-ray image obtained by irradiating with the first X-ray, the second transmitted X-ray image obtained by irradiating with the second X-ray, and the third transmitted X-ray image obtained by irradiating with the third X-ray, to detect the first foreign object and the second foreign object. Specifically, the second transparent X-ray image and 1 transparent The first foreign object is detected by differential processing with the X-ray image, and the third transparent X-ray image and 2 transparent The second foreign object is detected by differential processing with the X-ray image. The display control unit 5d may display the detected first and second foreign objects separately, or it may color-code the first and second foreign objects in a single image using different colors. Note that the first foreign object is the third transparent X-ray image and 1 transparent Detection may also be performed by differential processing with an X-ray image.

[0044] Furthermore, the signal processing device 5 may also include a correction unit that corrects for differences in X-ray intensity irradiated onto the sample W from each of the multiple optical elements 3. This correction unit may correct the parameters used when generating the transmitted X-ray image in the image generation unit 5a based on the optical arrangement of the X-ray source 2, the transmitted X-ray detection unit 4, and the multiple optical elements 3. Alternatively, the correction unit may correct multiple transmitted X-ray images based on the optical arrangement of the X-ray source 2, the transmitted X-ray detection unit 4, and the multiple optical elements 3.

[0045] Furthermore, the signal processing device 5 may also include a sensitivity correction unit that corrects the detection sensitivity of each of the multiple transmission X-ray detectors 4a and 4b to match.

[0046] Furthermore, although the above embodiment involved spectrally separating X-rays from one X-ray source 2 into X-rays of different energy ranges using multiple optical elements 3, it is also possible to have multiple X-ray sources 2. For example, an X-ray source 2 may be provided corresponding to each of the multiple optical elements 3.

[0047] Furthermore, although the above embodiment had a configuration with multiple optical elements and multiple transmission X-ray detectors, it may also have a configuration with one optical element and one transmission X-ray detector. In this case, the optical element can be used to spectrally analyze and focus X-rays with energy higher than the K absorption edge of the foreign substance.

[0048] Furthermore, the configuration for spectrally separating the X-rays from the X-ray source 2 into X-rays of a single energy range and irradiating the sample W may also be the configuration shown in Figure 6. In the configuration shown in Figure 6, two identical optical elements 3 are arranged facing each other. Here, the two optical elements 3 are curved spectrometers that spectrally separate (monochromatize) X-rays of the same energy range and simultaneously focus them into a line. The two optical elements 3 are arranged so that the X-rays focused into a line by each optical element 3 coincide on the sample W. In addition, a first collimator 81 is provided between the X-ray source and the optical elements 3 to remove X-rays that do not enter the optical elements 3, and a second collimator 82 is provided between the optical elements 3 and the sample W to remove X-rays other than those in the desired energy range. A third collimator 83 may also be provided between the second collimator and the sample W to remove unwanted X-rays as needed. With the optical system configuration shown in Figure 6, the intensity of the X-rays irradiated onto the sample W can be improved. As a result, the cumulative dose in the transmitted X-ray detection unit can be increased without increasing the counting time, and the contrast of transmitted X-rays can be increased even when transported at a higher speed than before. Consequently, the accuracy and speed of foreign object inspection of samples can be improved.

[0049] Furthermore, in addition to the configuration of the above embodiment, the configuration may also include a notification unit that notifies the user, such as by issuing an error, when the foreign object detection unit detects a foreign object.

[0050] In addition, although the above embodiment involved inspecting the sample W being transported by the transport mechanism 6 for foreign matter, a standalone type may also be used in which the sample is placed on a fixed inspection table for foreign matter inspection.

[0051] Furthermore, various modifications and combinations of the embodiments are permitted, as long as they do not contradict the spirit of the present invention. [Industrial applicability]

[0052] According to the present invention, the detection sensitivity of foreign substances in a sample can be improved in a transmission X-ray inspection apparatus. [Explanation of symbols]

[0053] 100... X-ray transmission inspection device W... Sample 2...X-ray source 3(3a, 3b)...Optical element 4. Transmission X-ray detection unit 4a, 4b... Transmission X-ray detectors 5. Signal Processing Device 51. Image Processing Unit 52...Display Control Unit

Claims

1. An X-ray source that emits X-rays containing multiple energy ranges that are different from each other, An optical element that spectrally separates the aforementioned X-rays into X-rays in one energy range and focuses them toward a sample, The system includes a transmitted X-ray detection unit that detects transmitted X-rays that have passed through the sample, It is used in conjunction with a transport mechanism for transporting the aforementioned sample, The optical element and the transmitted X-ray detection unit are arranged to sandwich the sample being transported by the transport mechanism. The optical element is a curved spectrometer that focuses X-rays in one energy range in a line shape, The transmitted X-ray detection unit is a line sensor provided in correspondence with the line-shaped focused X-rays, in a transmitted X-ray inspection apparatus.

2. The transmission X-ray inspection apparatus according to claim 1, wherein the optical element spectrally separates the sample into X-rays in an energy range higher than the X-ray absorption edge of the foreign substance to be detected.

3. The transmission X-ray inspection apparatus according to claim 1, further comprising two optical elements that spectrally separate the aforementioned X-rays into X-rays of the same energy range and focus them toward a sample.

4. The optical element has multiple types, The transmission X-ray inspection apparatus according to claim 1, wherein the plurality of optical elements spectrally separate into X-rays in different energy ranges.

5. The optical element has two types, One of the two types of optical elements spectrally separates the sample into X-rays in an energy range higher than the X-ray absorption edge of the foreign substance to be detected. The transmission X-ray inspection apparatus according to claim 4, wherein the other of the two types of optical elements spectrally separates X-rays in an energy range lower than the X-ray absorption edge.

6. The transmission X-ray inspection apparatus according to claim 4, wherein the plurality of optical elements spectrally separate X-rays from one X-ray source into X-rays in different energy ranges.

7. The transmission X-ray inspection apparatus according to claim 4, wherein the transmission X-ray detection unit has a plurality of transmission X-ray detectors for generating a plurality of transmission X-ray images corresponding to each of the X-rays in different energy ranges.

8. The system further includes an image processing unit that processes the transmitted X-ray images generated using each of the plurality of transmitted X-ray detectors. The transmission X-ray inspection apparatus according to claim 7, wherein the image processing unit performs difference processing using a plurality of transmission X-ray images corresponding to each of the X-rays in different energy ranges to detect foreign matter in the sample.

9. The system further includes a display control unit that displays the aforementioned transmitted X-ray image on a display, The transmission X-ray inspection apparatus according to claim 8, wherein the display control unit displays the foreign object detected by the image processing unit with color.

10. This involves inspecting two different types of foreign objects, the first and second. The optical element includes a first optical element that spectrally separates the X-rays into first X-rays in an energy range lower than the X-ray absorption edge of the first foreign substance, a second optical element that spectrally separates the X-rays into second X-rays in an energy range higher than the X-ray absorption edge of the first foreign substance and lower than the X-ray absorption edge of the second foreign substance, and a third optical element that spectrally separates the X-rays into third X-rays in an energy range higher than the X-ray absorption edge of the second foreign substance. The X-ray transmission inspection apparatus according to claim 8, wherein the image processing unit performs difference processing using a first transmitted X-ray image obtained by irradiating with the first X-ray, a second transmitted X-ray image obtained by irradiating with the second X-ray, and a third transmitted X-ray image obtained by irradiating with the third X-ray to detect the first foreign object and the second foreign object.

11. The transmission X-ray inspection apparatus according to claim 4, further comprising a correction unit for correcting the difference in X-ray intensity irradiated onto the sample from each of the multiple types of optical elements.

12. X-rays, which include multiple energy ranges and are emitted from an X-ray source, are spectrally separated into X-rays of a single energy range by an optical element, and then focused toward a sample being transported by a transport mechanism. The transmitted X-rays that have passed through the aforementioned sample are detected by a transmitted X-ray detection unit. The optical element and the transmitted X-ray detection unit are arranged to sandwich the sample being transported by the transport mechanism. The optical element is a curved spectrometer that focuses X-rays in one energy range in a line shape, A transmission X-ray inspection method, wherein the transmission X-ray detection unit is a line sensor provided in correspondence with the line-shaped focused X-rays.

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