X-ray imaging device and control method thereof

Abstract

Provided are an X-ray imaging device and a control method thereof. The X-ray imaging device according to an embodiment of the present invention includes: a transfer unit for transferring an electrode material of a battery cell; an X-ray generator for irradiating the electrode material of the battery cell with X-rays; an X-ray detector for detecting X-rays irradiated from the X-ray generator and having passed through the electrode material so as to generate projection data; a processor for generating a tomographic image on the basis of a plurality of projection data generated through the X-ray detector; and an image analysis unit for detecting a defective part, which is generated in a notching process, present in the electrode material of the battery cell by using the tomographic image.

Description

X-ray imaging device and its control method

[0001] The present invention relates to an X-ray photographing device and an X-ray photographing image processing method, and more particularly, to an X-ray photographing device and an X-ray image processing method capable of inspecting defects in secondary battery cell electrode materials.

[0002] When an X-ray imaging system captures a 2D X-ray image, the 2D X-ray image is an image in which X-rays are projected in one direction toward the X-ray imaging target. Therefore, when X-rays are projected toward the target in one direction, a problem occurs in which the image of the target overlaps and is obscured.

[0003] Meanwhile, to solve these problems, a representative device for irradiating patients with X-rays and taking pictures of an object is a computed tomography (CT) device. Among medical image processing devices, a computed tomography (CT) device, which is a tomography device, can provide cross-sectional images of an object, and has the advantage of being able to express the internal structure of an object (e.g., organs such as kidneys and lungs) without overlapping compared to a general X-ray device, so it is widely used for the precise diagnosis of diseases.

[0004] Recently, a tomosynthesis (DTS) X-ray imaging system that creates 3D images with low radiation compared to computed tomography (CT) devices has been introduced.

[0005] The tomosynthesis system is a technique that can obtain three-dimensional images with a low dose compared to computed tomography (CT), and can provide depth-specific tomographic images to eliminate overlapping or occlusion effects.

[0006] A tomosynthesis system typically rotates an analog X-ray generator in an arch shape around a rotational axis, and an X-ray detector moves or rotates according to the position of the X-ray generator while capturing multiple X-ray images, and then reconstructs the image into a three-dimensional image using a reconstruction algorithm.

[0007] Meanwhile, as development of secondary batteries has been actively progressing recently, technical issues regarding defect inspection of electrode materials when producing secondary batteries are also arising.

[0008] Previously, to inspect the thickness of the sealing portion of a battery cell, two laser confocal sensors were placed facing each other to simultaneously measure the top and bottom surfaces.

[0009] When using a confocal sensor, there is a problem in that it uses a point measurement method, so it is not possible to obtain information about the entire surface.

[0010] In addition, the conventional method of measuring the thickness of a display cell using a confocal sensor may cause errors in displacement values ​​due to vibrations and shaking caused by the movement of the conveying part during the mass production process, and it is impossible to measure fine protrusions using the point measurement method.

[0011] In addition, when utilizing a point-type confocal sensor, there is a problem that the error in measuring the thickness of the electrode material in the area where the insulating material used to create the battery cell covers the electrode increases, and that it is difficult to fully inspect for defects (burrs, dross, etc.) in the notching process.

[0012] The problem to be solved by the present invention is to provide an X-ray photographing device capable of detecting defects that may occur in the electrode material coating thickness and notching process of a battery cell using an X-ray photographing device instead of a confocal displacement sensor, and a control method thereof.

[0013] An X-ray photographing device according to an embodiment of the present invention includes a transport unit that transports an electrode material of a battery cell, an X-ray generator that irradiates X-rays to the electrode material of the battery cell, an X-ray detector that detects X-rays irradiated from the X-ray generator and transmitted through the electrode material to generate projection data, a processor that generates a tomographic image based on a plurality of projection data generated through the X-ray detector, and an image analysis unit that detects a defective part existing in the electrode material of the battery cell generated in a notching process using the tomographic image.

[0014] In an embodiment, the image analysis unit is characterized in that it detects at least one of a notching burr and a notching dross generated in the electrode material of the battery cell during the notching process using the single-layer image.

[0015] In an embodiment, the image analysis unit is characterized in that it performs measurement of at least one of the maximum thickness of the coating applied to the end of the positive electrode material or negative electrode material applied to the electrode material of the battery cell, the slope of the coating, and the coating start reference point using the single-layer image.

[0016] In an embodiment, the X-ray detector is characterized in that the distance to the transfer unit is variable.

[0017] In an embodiment, the magnification of the cross-sectional image is characterized in that it changes based on the change in the distance between the X-ray detector and the transport unit.

[0018] In an embodiment, the X-ray generator includes a plurality of X-ray sources, and the plurality of X-ray sources are characterized in that they are formed to irradiate X-rays to the electrode material at different intervals and angles.

[0019] In an embodiment, the processor is characterized in that it generates a plurality of tomographic images using a plurality of projection data detected by the X-ray detector using the plurality of X-ray sources, and obtains three-dimensional information about the electrode material using the plurality of tomographic images.

[0020] In an embodiment, the X-ray generator includes at least one X-ray source and an image sensor, wherein the at least one X-ray source and the image sensor are arranged to photograph the electrode material at different intervals and angles, and the processor is characterized in that it obtains three-dimensional information about the electrode material by using a cross-sectional image obtained through the X-ray source and an image obtained through the image sensor.

[0021] In an embodiment, the image analysis unit includes an image processing unit that receives the single-layer image, performs clustering by material region, sets a region of interest to be inspected, and a defect reading unit that detects at least one of a notching burr and a notching dross for the region of interest and determines the thickness of the electrode material.

[0022] In an embodiment, the image processing unit includes an image preprocessing module that performs preprocessing on a tomographic image, an image clustering module that performs clustering by material region in the tomographic image using the preprocessed tomographic image, an attenuation coefficient correction module that corrects the attenuation coefficient based on the material-specific attenuation coefficient for each clustering region and the image analysis result, a thickness map generation module that estimates the thickness of an object and creates a map using the corrected attenuation coefficient and brightness information of the tomographic image, a region of interest setting module that sets a region of interest for performing thickness measurement and defect measurement of an electrode material, and a postprocessing module that removes noise components through a postprocessing process on the map for the thickness.

[0023] In an embodiment, the defective reading unit is characterized in that it determines a defective product when the thickness of the electrode material and the measurement value of the defective part measured within the area of ​​interest set by the image processing unit each exceed a set standard value.

[0024] According to the present invention, the present invention can simultaneously detect the thickness of the electrode material of a battery cell and burrs and dross that may occur during the notching process.

[0025] According to the present invention, while a confocal sensor uses a point measurement method, an X-ray image uses a surface measurement method to measure changes in the thickness of an electrode material over a wider area, thereby increasing efficiency in quality control.

[0026] The present invention can accurately obtain thickness information on the electrode material coating due to the insulating material's relatively high X-ray transmittance even when the insulating material is applied to the electrode.

[0027] According to the present invention, measurement errors that may occur due to vibration or shaking of the conveying part can be minimized.

[0028] Further scope of the applicability of the present invention will become apparent from the detailed description below. However, since various modifications and variations within the spirit and scope of the present invention will become apparent to those skilled in the art, it should be understood that the detailed description and specific examples, such as preferred embodiments of the present invention, are given by way of example only.

[0029] Figure 1 is a drawing for explaining an X-ray photographing device according to a conventional tomosynthesis system.

[0030] FIGS. 2 and 3 are block diagrams illustrating an X-ray imaging device according to an embodiment of the present invention.

[0031] Figure 4 is a conceptual diagram for explaining an image analysis unit according to one embodiment of the present invention.

[0032] FIGS. 5, 6, 7, 8, and 9 are conceptual diagrams for explaining a method for detecting thickness and defective parts in an electrode material of a battery cell using an X-ray photographing device according to an embodiment of the present invention.

[0033] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers, and redundant descriptions thereof will be omitted. The suffixes "module" and "part" used for components in the following description are assigned or used interchangeably only for the convenience of writing the specification, and do not in themselves have distinct meanings or roles. In addition, when describing the embodiments disclosed in this specification, if it is determined that a specific description of a related known technology may obscure the gist of the embodiments disclosed in this specification, a detailed description thereof will be omitted. In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and technical scope of the present invention.

[0034] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0035] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0036] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0037] In this application, terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but should be understood not to exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0038] Figure 1 is a drawing for explaining an X-ray photographing device according to a conventional tomosynthesis system.

[0039] In a conventional tomosynthesis system (10), an X-ray generator (101) rotates about 20 to 50 degrees around a predetermined rotation axis while irradiating an X-ray to a photographing target (102). An X-ray detector (103) can generate an electrical signal corresponding to the dose of the X-ray transmitted.

[0040] Meanwhile, when the X-ray generator (101) rotates and irradiates the photographing target (102) with X-rays, the projected X-rays are detected by the X-ray detector (103), and a plurality of projection data (106, 107, 108) can be generated.

[0041] Meanwhile, based on the first plane (Plane 1) and the second plane (Plane 2) of the photographing target (102), each of the first point (104) and the second point (105) can be projected by the X-ray emitted by the X-ray generator (101) and mapped to each of the plurality of projection data (106, 107, 108).

[0042] In this case, the first point (104) and the second point (105) mapped to each of the plurality of projection data (106, 107, 108) may be mapped differently due to the change in the incident angle according to the rotational movement of the X-ray generator (101). Therefore, an additional step of reconstructing a 2D or 3D X-ray tomographic image of the photographing target (102) based on the plurality of projection data (106, 107, 108) is required.

[0043] FIGS. 2 and 3 are block diagrams illustrating an X-ray imaging device according to an embodiment of the present invention.

[0044] Referring to FIG. 2, the X-ray imaging device (20) may include an X-ray generator (210), an X-ray detector (820), a memory (250), and a processor (870).

[0045] The X-ray generator (210) may include an X-ray source. The X-ray source may be configured to be movable along a plane parallel to the X-ray detector (230).

[0046] For example, the X-ray generator (210) may be formed with a first frame corresponding to the X-axis and a second frame corresponding to the Y-axis, and may include a first axis formed to slide along the first frame and a second axis formed to slide along the second frame.

[0047] The X-ray source can be positioned at the intersection of the first axis and the second axis.

[0048] Although not shown, the first frame and the second frame may be provided with an actuator (or motor) that moves the first axis or the second axis, and the actuator may be driven under the control of the processor (870).

[0049] The processor (870) can control the actuators provided in the first frame and the second frame to position the X-ray source at a desired position or at desired coordinates, thereby positioning the X-ray source at a desired position through movement of the first and second axes.

[0050] Accordingly, the X-ray source is formed to be movable along a plane parallel to the X-ray detector (230), and can irradiate X-rays perpendicularly to the detector at a position designated by the control of the processor (870).

[0051] The X-ray detector (230) can generate an electrical signal corresponding to the dose of the X-rays transmitted. The X-ray detector (230) can generate projection data by generating the electrical signal.

[0052] The memory (250) stores programs for each signal processing and control within the processor (270), and can store signal-processed images, voices, or data signals, etc. The memory (250) can store a plurality of projection data.

[0053] The processor (870) can control the movement of the X-ray generator (210) or the X-ray detector (230), or control the on or off of the X-ray off when the X-ray source of the X-ray generator (210) is positioned at a desired position.

[0054] Additionally, the processor (870) can store a plurality of projection data generated from the X-ray detector (230) in the memory (250).

[0055] Additionally, the processor (870) can reconstruct a plurality of projection data into a 2D or 3D X-ray image (tomographic image), which is a cross-sectional image of the photographing target. For example, the processor (870) can apply a predetermined reconstruction algorithm based on a plurality of projection data to generate a 2D or 3D X-ray tomographic image.

[0056]

[0057] Meanwhile, the present invention can detect the thickness of the electrode material of a battery cell required for forming a secondary battery by irradiating it with X-rays and burrs and / or dross that may occur during the notching process.

[0058] As is widely known, secondary batteries are batteries that can be repeatedly charged and discharged, and are used as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs).

[0059] Generally, types of secondary batteries include nickel cadmium batteries, nickel hydrogen batteries, lithium ion batteries, and lithium ion polymer batteries.

[0060] These secondary batteries are used not only in small products such as digital cameras, P-DVDs, MP3Ps, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in large products requiring high output such as electric vehicles and hybrid vehicles, as well as in power storage devices that store surplus generated power or renewable energy and power storage devices for backup.

[0061] To manufacture these secondary batteries, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to manufacture a positive electrode and a negative electrode, and these are laminated on both sides of a separator to form an electrode assembly of a predetermined shape. Then, the electrode assembly is housed in a battery case, filled with electrolyte, and sealed.

[0062] Secondary batteries can be classified into pouch type battery cells and can type battery cells depending on the material of the case that houses the electrode assembly. In particular, a pouch type battery cell (hereinafter, “battery cell”) houses an electrode assembly and an electrolyte in a pouch.

[0063] And, as one of the quality evaluations of these battery cells, it is common to inspect the thickness of the electrode material of the battery cell.

[0064] To this end, referring to FIG. 3, the present invention may include a transport unit (820) formed to transport an electrode material of a battery cell, an X-ray generator (210) that irradiates X-rays to the electrode material of the battery cell, an X-ray detector (230) that detects X-rays irradiated from the X-ray generator (210) and transmitted through the electrode material to generate projection data, a processor (270) that generates a tomographic image (or X-ray image) based on a plurality of projection data generated through the X-ray detector, and an image analysis unit (860) that detects a defective part existing in the electrode material of the battery cell generated in the notching process using the tomographic image.

[0065] Here, the image analysis unit (860) may be a processor (270) or a control unit that detects the thickness and / or defective portion of the electrode material of the battery cell using a cross-sectional image acquired through X-ray. That is, the operation / function / control method performed in the image analysis unit (860) may be performed by the processor (270) (or the control unit).

[0066] In this specification, for the convenience of explanation, the image analysis unit (860) is described as a separate component separated from the processor (270). In addition, the image analysis unit (860) may be implemented as an independent module separated from the processor (270) and configured to detect the thickness and / or defective portion of the electrode material of the battery cell using an X-ray tomography image.

[0067] FIG. 4 is a conceptual diagram for explaining an image analysis unit according to an embodiment of the present invention, and FIGS. 5, 6, 7, 8, and 9 are conceptual diagrams for explaining a method for detecting thickness and defective parts in an electrode material of a battery cell using an X-ray photographing device according to an embodiment of the present invention.

[0068] Referring to FIG. 5, the X-ray photographing device of the present invention may include a transport unit (820) formed to transport an electrode material (500) of a battery cell.

[0069] The X-ray generator (210) can be positioned at the top of the transport section to irradiate the electrode material with X-rays.

[0070] The X-ray detector (230) can detect X-rays emitted from the X-ray generator (210) and transmitted through the electrode material (500) to generate projection data.

[0071] The X-ray generator (210) can irradiate X-rays multiple times while the electrode material moves in one direction by the transfer unit (820).

[0072] The X-ray detector (230) can obtain a plurality of projection data based on a plurality of X-rays irradiated while the electrode material is moved in one direction by the transfer unit (820).

[0073] The processor (270) can generate a cross-sectional image (or X-ray image) of the electrode material of the battery cell based on projection data (or a plurality of projection data).

[0074] The processor (270) can transmit the generated single-layer image to the image analysis unit (860).

[0075] The image analysis unit (860) can detect the thickness and defective parts of the electrode material of the battery cell using the single-layer image.

[0076] In this way, the process of taking a cross-sectional image using X-rays and measuring and inspecting the thickness and defective parts of the electrode material of the battery cell can be performed at least once during the process of producing the electrode material of the battery cell, as illustrated in FIG. 7.

[0077] For example, the process of measuring and inspecting the thickness and defective parts of the electrode material of a battery cell by taking a cross-sectional image using X-rays can be performed first after drying after coating the top surface of the electrode material of the battery cell, and secondly after drying and notching after coating the bottom surface.

[0078] Here, the notching process can be referred to as the process of cutting out only the necessary parts from the electrode plate that has completed the electrode process.

[0079] The X-ray photographing device of the present invention can measure various parts and various types of electrode materials of a battery cell.

[0080] As shown in (a) of FIG. 8, the image analysis unit (860) can perform measurement and inspection (detection) of the thickness, shape and defective portion of the tab foil stamping surface (910), the thickness, shape and defective portion of the tab insulation or electrode stamping surface (920), and the thickness, shape and defective portion of the bottom stamping surface (930) using a cross-sectional image generated through X-rays.

[0081] In addition, as illustrated in (b) of FIG. 8, the image analysis unit (860) can detect a defective portion (e.g., at least one of a notching burr and a notching dross) that occurs in the electrode material of the battery cell during the notching process using a single-layer image.

[0082] Notching burrs can be a defect that may occur during the mold notching process.

[0083] Notching dross refers to a defective part that can occur during the laser notching process.

[0084] In addition, referring to FIG. 9(a), the electrode material of the battery cell may include at least one of a positive electrode material or a negative electrode material, a coating (or coating material), and an insulator applied to a foil layer.

[0085] The image analysis unit (860), as illustrated in FIG. 9(a), can measure at least one of the maximum thickness of the coating applied to the end of the positive or negative electrode material applied to the electrode material of the battery cell, the slope of the coating, and the coating start reference point using a single-layer image.

[0086] Unlike Fig. 9(a) where the electrode material of the electric cell is single-sidedly coated, as shown in Fig. 9(b), even when the electrode material of the electric cell is double-sidedly coated, the image analysis unit (860) can use the single-layer image to measure at least one of the maximum thickness of the coating applied to the end of the positive or negative electrode material applied to the electrode material of the battery cell, the slope of the coating, and the coating start reference point.

[0087] Meanwhile, referring to FIG. 5, the X-ray detector (230) can be formed so that the distance to the transport unit (820) (more precisely, the vertical distance (or shortest distance) from the X-ray detector (230) to the conveyor belt of the transport unit) (d) is variable.

[0088] Through this, the magnification of the single-layer image can be changed based on the variation of the separation distance (d) between the X-ray detector (230) and the transport unit (820).

[0089] For example, in a tomographic image, the closer the separation distance is, the greater the magnification (allowing for a narrow area to be viewed with great magnification), and the farther the separation distance is, the smaller the magnification (allowing for a wide area to be viewed).

[0090] Meanwhile, the X-ray photographing device of the present invention may include a plurality of X-ray sources (or a plurality of X-ray generators).

[0091] Referring to Fig. 6(a), only one X-ray generator (210) may be provided. In this case, the X-ray generator (210) irradiates the electrode material (500) of the battery cell with X-rays at least once to obtain at least one projection data, and uses the obtained projection data to create a cross-sectional image to detect the thickness and defective parts of the electrode material.

[0092] Referring to FIG. 6(b), the X-ray generator (210) may include a plurality of X-ray sources (210a, 210b) (or a plurality of X-ray generators).

[0093] The above plurality of X-ray sources (210a, 210b) can be formed (or arranged) to irradiate X-rays to the electrode material at different intervals and angles based on the electrode material of the electrode cell.

[0094] The processor (270) can generate a plurality of tomographic images using a plurality of projection data detected by the X-ray detector using the plurality of X-ray sources, and can obtain three-dimensional information about the electrode material using the plurality of tomographic images.

[0095] The image analysis unit (860) can detect the thickness and defective parts (notching burrs and notching dross) of the electrode material using three-dimensional information about the electrode material.

[0096] For example, the image analysis unit (860) can determine a portion where a foil layer that has penetrated an insulating layer exists as a notching burr, and can determine a portion of the foil layer that has bulged to a certain thickness or more (or a portion that is thicker by a certain ratio or more compared to the thickness of the foil layer) as a notching dross.

[0097] In another embodiment, the X-ray generator may include at least one X-ray source (or X-ray generator) (210) and an image sensor (600) (or displacement sensor), as illustrated in FIG. 6(c).

[0098] The above image sensor (600) may be, for example, a camera.

[0099] The above at least one X-ray source (210) and image sensor (600) can be arranged to photograph the electrode material at different angles and angles.

[0100] The processor (270) can obtain three-dimensional information about the electrode material (500) of the battery cell by using a cross-sectional image obtained through an X-ray source and an image obtained through the image sensor.

[0101] In summary, the X-ray photographing device of the present invention is composed of a transport unit (820), an X-ray generator (210), an X-ray detector (230), a sensor unit (840), an image analysis unit (860), and a processor (270), and can perform detection of secondary battery electrode defects.

[0102] This X-ray photographing device can be placed in a secondary battery electrode material coating and notching process line, and can photograph and create a cross-sectional image by positioning a battery cell (electrode material of an electric cell) between an X-ray generator (210) and an X-ray detector (230).

[0103] The elliptical imaging device of the present invention can adjust the image magnification by adjusting the distance between the battery cell and the X-ray detector (230).

[0104] An X-ray imaging device can obtain three-dimensional information about the shape of a defective battery cell by using two or more X-ray images (tomograms) obtained by sequentially operating at least two X-ray generators arranged at arbitrary intervals and angles.

[0105] In addition, the X-ray imaging device can obtain three-dimensional information about the shape of a battery cell by arranging one or more X-ray generators and one or more image sensors at arbitrary intervals and angles, and using one or more X-ray images (tomograms) obtained after imaging and one or more image sensor images.

[0106] In addition, the X-ray imaging device can obtain one or more X-ray generators and one or more displacement sensors at arbitrary intervals and angles, acquire one or more X-ray images and one or more displacement sensor data obtained after imaging, and utilize the same to obtain three-dimensional information about the shape of a battery cell and the shape of a battery cell defect.

[0107] Below, each configuration for detecting the thickness and defective parts of the electrode material of a battery cell using X-ray images (tomographic images) will be described in more detail.

[0108] Referring to FIG. 3, the X-ray generator (210) can generate X-rays with a tube voltage and tube current set for battery cell inspection. When two or more generators are provided, the processor (270) can sequentially operate multiple X-ray generators.

[0109] The transport unit (820) can be formed to transport battery cells in a battery cell manufacturing process line.

[0110] An X-ray detector (230) can irradiate X-rays when a battery cell reaches a position set for measurement, obtain an X-ray transmission image (tomogram), and then transmit the image to an image analysis unit (860).

[0111] The processor (270) (or control unit) can control and synchronize the operation of the X-ray generator (210), the transport unit (820), the X-ray detector (230), and the sensor unit (840) and provide functions.

[0112] Data from various sensors are collected for inspection of the sensor unit (840). The sensor unit (840) may include an image sensor or a displacement sensor, as illustrated in FIG. 6. The image analysis unit (860) may acquire additional information using the image sensor or displacement sensor included in the sensor unit (840), thereby increasing measurement accuracy.

[0113] Referring to FIG. 3, the image analysis unit (860) may include an image processing unit (870) that receives a single-layer image, performs clustering by material region, sets a region of interest (ROI) to be inspected, and a defect reading unit (880) that detects burrs (or dross) in the region of interest and determines the thickness of the electrode material.

[0114] Referring to FIG. 4, the image processing unit (870) may include an image preprocessing module (871) that performs preprocessing on a tomographic image. The image preprocessing module (image data preprocessing) (871) may perform a preprocessing process on an X-ray image (tomographic image) and image sensor image data. The image preprocessing module (871) may remove noise from the image and improve the quality of the image, thereby increasing the accuracy in subsequent processing.

[0115] The image processing unit (870) may include an image clustering module (872) that performs clustering by material region in a single-layer image using a preprocessed image.

[0116] The image clustering module (872) can cluster images by material region, such as a cathode region or a foil region, based on a preprocessed tomographic image. Here, clustering may refer to a method of classifying data into several groups based on concepts such as similarity. In an X-ray imaging device, clustering by material in a tomographic image can be performed based on at least one of an attenuation coefficient and the intensity of the transmitted X-ray (or brightness information in the tomographic image).

[0117] The image processing unit (870) may include an attenuation coefficient correction module (873) that corrects the attenuation coefficient based on the material-specific attenuation coefficient for each clustering area and the image analysis results.

[0118] The attenuator factor correction module (873) can correct the attenuation factor using the attenuation factor unique to the material initially set for each clustering area and the image analysis results.

[0119] The image processing unit (870) may include a thickness map generation module (874) that estimates the thickness of the subject (electrode material of the electrode cell) and creates a map using the corrected attenuation coefficient and brightness information of the single-layer image.

[0120] The thickness map generation module (874) can estimate the thickness of an object using the calculated attenuation coefficient and image brightness information and create a map of the thickness.

[0121] The image processing unit (870) may include a post-processing module (875) that removes noise components from the map for the thickness through a post-processing process.

[0122] The post-processing module (875) can improve thickness accuracy by removing noise components and adjusting scale, etc. through a post-processing process for the thickness map.

[0123] The image processing unit (870) may include a region of interest generation module (876) for setting a region of interest for performing thickness measurement and defect measurement of the electrode material.

[0124] The region of interest (ROI) setting module (876) can designate the region of the inspection area to be measured, such as the electrode material thickness measurement location and the notching defect measurement location.

[0125] The defective reading unit (880) can determine a defective product if the thickness of the electrode material and the measurement value of the defective portion measured within the area of ​​interest set by the image processing unit (870) each exceed the set standard value.

[0126] The defective reading unit (880) may include an electrode thickness determination module (884) that determines the thickness of the electrode material within the region of interest, and a defective detection module (882) that determines a defective part (such as the size or height of a burr or dross) within the region of interest to be defective if it exceeds a standard value.

[0127] The configurations described in FIGS. 3 and 4 can be implemented as separate modules or chips in hardware, and can be configured to perform the functions that each configuration is configured to perform by transmitting and receiving data to each other through electrical signals.

[0128] Additionally, the configurations described in FIGS. 3 and 4 may be implemented as componentized software modules that perform software-distinct functions within a single processor.

[0129] According to the present invention, the present invention can simultaneously detect the thickness of the electrode material of a battery cell and burrs and dross that may occur during the notching process.

[0130] According to the present invention, while a confocal sensor uses a point measurement method, an X-ray image uses a surface measurement method to measure changes in the thickness of an electrode material over a wider area, thereby increasing efficiency in quality control.

[0131] The present invention can accurately obtain thickness information on the electrode material coating due to the insulating material's relatively high X-ray transmittance even when the insulating material is applied to the electrode.

[0132] According to the present invention, measurement errors that may occur due to vibration or shaking of the conveying part can be minimized.

[0133] Further scope of the applicability of the present invention will become apparent from the detailed description below. However, since various modifications and variations within the spirit and scope of the present invention will become apparent to those skilled in the art, it should be understood that the detailed description and specific examples, such as preferred embodiments of the present invention, are given by way of example only.

[0134] The present invention described above can be implemented as computer-readable code on a medium in which a program is recorded. Computer-readable media include all types of recording devices that store data that can be read by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid state disks (SSDs), silicon disk drives (SDDs), ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., and also include media implemented in the form of carrier waves (e.g., transmission via the Internet). In addition, the computer may include a control unit (180) of a terminal. Therefore, the above detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. A transport section for transporting electrode materials of a battery cell; An X-ray generator for irradiating X-rays onto the electrode material of the above battery cell; An X-ray detector that detects X-rays irradiated from the X-ray generator and transmitted through the electrode material to generate projection data; A processor for generating a tomographic image based on a plurality of projection data generated through the X-ray detector; and An X-ray imaging device including an image analysis unit that detects defective parts existing in electrode materials of a battery cell generated in a notching process using the above-mentioned single-layer image.

2. In paragraph 1, The above image analysis unit, An X-ray imaging device characterized in that it detects at least one of a notching burr and a notching dross generated in the electrode material of the battery cell during the notching process by using the above-mentioned cross-sectional image.

3. In paragraph 1, The above image analysis unit, An X-ray imaging device characterized in that it performs measurement of at least one of the maximum thickness of a coating applied to an end of a positive electrode material or a negative electrode material applied to an electrode material of the battery cell, the inclination of the coating, and the coating start reference point using the above-mentioned cross-sectional image.

4. In paragraph 1, The above X-ray detector, An X-ray photographing device characterized in that the distance to the above-mentioned transfer section is formed so as to be variable.

5. In paragraph 1, An X-ray photographing device, characterized in that the magnification of the above-mentioned cross-sectional image is changed based on the variation of the distance between the X-ray detector and the transport unit.

6. In paragraph 1, The above X-ray generator comprises a plurality of X-ray sources, An X-ray photographing device, characterized in that the plurality of X-ray sources are formed to irradiate X-rays to the electrode material at different intervals and angles.

7. In paragraph 6, The above processor, Using the above multiple X-ray sources, multiple projection data detected by the X-ray detector are used to generate multiple tomographic images, An X-ray imaging device characterized in that it obtains three-dimensional information about the electrode material by using the plurality of tomographic images.

8. In paragraph 1, The above X-ray generator comprises at least one X-ray source and an image sensor, The at least one X-ray source and the image sensor are arranged to photograph the electrode material at different intervals and angles, An X-ray imaging device characterized in that the processor obtains three-dimensional information about the electrode material by using a cross-sectional image obtained through the X-ray source and an image obtained through the image sensor.

9. In paragraph 1, The above image analysis unit, An image processing unit that receives the above-mentioned single-layer image, performs clustering by material area, and sets an area of ​​interest to be inspected; and An X-ray imaging device including a defect reading unit for detecting at least one of a notching burr and a notching dross for a region of interest and determining a thickness of an electrode material.

10. In paragraph 9, The above image processing unit, Image preprocessing module that performs preprocessing on single-layer images; An image clustering module that clusters material regions in a tomographic image using preprocessed tomographic images; An attenuation coefficient correction module that corrects the attenuation coefficient based on the material-specific attenuation coefficient and image analysis results for each clustering area; A thickness map generation module that estimates the thickness of an object using the compensated attenuation coefficient and the brightness information of a tomographic image and creates a thickness map; A post-processing module for removing noise components from a map for the above thickness through a post-processing process; and An X-ray imaging device including a region of interest setting module for setting a region of interest for performing thickness measurement and defect measurement of an electrode material.

11. In paragraph 9, The above defective reading part is, An X-ray imaging device characterized in that when the thickness and defective portion measurements of the electrode material measured within the region of interest set by the image processing unit each exceed a set standard value, the device is judged as defective.

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