Electrode inspection device

Abstract

Provided is an electrode inspection device configured to take an image of an electrode to visually inspect the electrode for defects, the electrode inspection device including a transparent visual holder configured to hold one end of the electrode, wherein the visual holder is formed with an opening portion to expose a predetermined area including two corner portions of the one end of the electrode.

Description

Technical Field

[0001] This application claims priority based on Korean Patent Application No. 10-2024-0047642, filed on April 8, 2024, the entire contents of which are incorporated herein by reference.

[0002] This invention relates to an inspection apparatus for inspecting electrodes and an electrode inspection method using the inspection apparatus. More specifically, this invention relates to a visual inspection apparatus for inspecting whether cut electrodes have dimensional defects, an inspection method using the visual inspection apparatus, and a battery manufacturing process including the inspection method. Background Technology

[0003] Based on the product group, secondary batteries offer ease of use and possess electrical characteristics such as high energy density. These batteries are widely used not only in portable devices but also in electric vehicles, hybrid vehicles powered by electric sources, and energy storage devices. These secondary batteries are attracting attention as a new energy source for improving environmental friendliness and energy efficiency, not only because of their primary advantage of significantly reducing fossil fuel use but also because they do not produce any byproducts from energy consumption.

[0004] Small mobile devices use one, two, or three battery cells per device, while medium to large devices such as vehicles require high output and large capacity. Therefore, medium to large battery modules or battery packs use multiple battery cells electrically connected together.

[0005] Meanwhile, as types of unit secondary battery cells, cylindrical battery cells, prismatic battery cells, and pouch battery cells are known. Since the goal is to manufacture medium-to-large-sized battery modules as small and lightweight as possible, prismatic and pouch batteries, which are stackable, highly integrated, and have low weight per unit capacity, are mainly used as battery cells for medium-to-large-sized battery modules.

[0006] Among these battery cells, pouch cells have various structures depending on the method used to manufacture the electrode assemblies they contain. In particular, recently, the zigzag stacking method has been frequently used to manufacture high-capacity stacked cells at high speed. This method involves alternately stacking anodes and cathodes between layers of a separator folded in a zigzag pattern. The manufacturing process for such stacked cells includes: a cutting step of cutting electrodes; a loading step of loading electrodes into a cassette; and a step of supplying the electrodes to a stacking device and assembling them with the separator.

[0007] Figure 1 The electrode after cutting is shown. (Reference) Figure 1The electrode 1, which is typically supplied for stacking electrode assemblies, has: a coated region 12 coated with an active material to initiate a battery reaction; an uncoated region 11 without an active material; and an insulating layer 13 coated at the boundary between the coated region 12 and the uncoated region 11 to prevent short circuits.

[0008] Electrode 1 is subjected to laser cutting to produce tabs 10 protruding from one side of electrode 1, and the cut electrode 1 is immediately subjected to a dimensional inspection step after the cutting step to detect dimensional defects such as the width and position of tabs 10 and the overall width of electrode 1.

[0009] Figure 2 and Figure 3 Clamping for visual inspection is shown Figure 1 The electrode manufacturing process. (See reference) Figure 2 and Figure 3 Immediately after the cutting step, electrode 1 is conveyed by being attracted to the conveying device 4 with its central portion. Here, in order to accurately check the dimensions without being affected by the sagging or warping of electrode 1, a pair of visual grippers 2 move up and down to grip one end of electrode 1. The visual grippers 2 are made of a transparent synthetic resin material such as acrylic resin and press the said end of electrode 1 flat while allowing visual inspection using camera 3.

[0010] Meanwhile, the vision gripper 2 moves laterally with the electrode 1 at the same speed as the electrode 1 is moved through the conveying device 4 to achieve faster inspection, and clamps and releases the electrode 1 by moving up and down.

[0011] Figure 4 Images taken for electrode dimensional inspection are shown. (Reference) Figure 4 As the visual gripper 2 clamps and releases the electrode 1 while moving laterally together with the electrode 1, a small frictional force is applied laterally between the visual gripper 2 and the electrode 1, which leaves a scratch S on the visual gripper 2 along the transport direction of the electrode 1.

[0012] When friction material accumulates on the scratches S in the coated area 12, the dark-colored active material enters the scratches S in powder form, and the scratches S may form increasingly clear lines. The problem is that the edges of the electrode 1 and the tab 10 cannot be accurately detected due to the scratches S, thus leading to over-detection of dimensional defects in the electrode 1.

[0013] Simultaneously, electrode 1 can also undergo a corner inspection step to detect defects caused by deformation and / or damage to its fragile corners. The corner inspection can be performed immediately after electrode 1 is cut and / or immediately before it is supplied for stacking.

[0014] Figure 5Images taken for corner inspection of electrodes are shown. (Reference) Figure 5 To detect deformation and / or damage at the corner of electrode 1, an image of electrode 1 is captured and used in a method for detecting the position and angle of the corner. To determine the precise position and angle of the corner, a method is primarily used that detects the horizontal and vertical axes forming the corner and detects the intersection and angle formed by these axes.

[0015] However, because the uncoated area 11 is thin, even if electrode 1 is free of defects, slight warping C may occur at the corners of electrode 1. As warping C occurs, the corner boundaries become blurred due to shading, making it difficult to accurately detect the horizontal and vertical axes, thus leading to over-detection of corner defects of electrode 1. Summary of the Invention

[0016] Technical issues

[0017] In order to solve the problems of the prior art, the present invention aims to provide an electrode inspection device and an electrode inspection method that can accurately detect dimensional defects in electrodes.

[0018] Specifically, the present invention aims to provide an electrode inspection device and an electrode inspection method that can prevent over-detection of defects caused by scratches resulting from friction with the electrode when clamping it to prevent it from sagging or warping.

[0019] The present invention also aims to provide an electrode inspection device capable of rapidly and accurately visually inspecting electrodes while moving laterally with the electrodes being transported, and an electrode inspection method using the electrode inspection device.

[0020] Another object of the present invention is to provide a battery manufacturing process in which dimensional defects of the electrodes can be accurately detected during the process of cutting and supplying electrodes for lamination.

[0021] The technical problem to be solved by the present invention is not limited to the above-described objectives. Other objectives and advantages not described herein will be understood through the following description and will become clearer through examples of the invention. Furthermore, it will be apparent that the objectives and advantages of the present invention can be achieved by the means set forth in the claims and combinations thereof.

[0022] Technical solution

[0023] To address the aforementioned problems, the present invention provides a structure for an electrode inspection apparatus for visually inspecting the presence of defects in an electrode by photographing the electrode. The electrode inspection apparatus includes: a transport device for transporting the electrode; a transparent visual clamp for clamping one end of the electrode; and a camera for photographing predetermined regions of interest containing two corners of one end of the electrode while the visual clamp is holding the electrode. The visual clamp may include an upper clamp and a lower clamp, which move vertically and clamp the electrode from above and below. At least one of the upper and lower clamps includes an opening that exposes the predetermined regions containing the two corners of one end of the electrode.

[0024] According to the present invention, an electrode inspection device is provided that can achieve more accurate visual inspection by avoiding scratches on the portion of the visual gripper corresponding to the corner of the electrode with the defect to be inspected.

[0025] The delivery device can deliver the electrode while it is attached to a portion spaced inward from the edge of the electrode at a predetermined distance. Here, the edge of the electrode may undergo deformations such as drooping or warping. However, by holding one end of the electrode with a vision gripper, the electrode can be photographed in a flat, unfolded state.

[0026] The vision gripper can move together with the electrode at the same speed as the electrode is moved by the conveying device. Specifically, according to one embodiment of the invention, the vision gripper can move up and down to grip or release the electrode while moving together with the electrode at the same speed as the electrode is moved by the conveying device. Therefore, visual inspection is performed simultaneously with electrode transport, thereby enabling high-speed electrode production and defect inspection.

[0027] Here, since both the electrodes and the vision holder move laterally and come into contact with each other, providing an opening can prevent potential damage to the electrodes or the vision holder.

[0028] The electrode may include a coated area with an active material and an uncoated area at one end, with an opening exposing at least a portion of the boundary between the coated and uncoated areas. This design prevents scratches caused by the active material and also prevents the darkening of scratches due to the accumulation of active material powder.

[0029] An opening can be provided at least in the lower gripper. In this case, active material powder generated by friction between the vision gripper and the electrode can be discharged downward through the opening, and recognition errors caused by the accumulation of active material powder can be prevented.

[0030] Preferably, the opening includes a region that does not overlap with the electrode. That is, since the opening is not blocked by the electrode and is completely open in the vertical direction, the discharge of the active material powder can proceed more smoothly.

[0031] According to one embodiment of the invention, an opening can be provided on both the upper and lower clamps. Therefore, the upper clamp will not be scratched by the electrode, and the active material powder can be discharged through the opening in the lower clamp. Here, each of the upper and lower clamps can define a portion of the edge of the opening and include a corner support that supports the inner portion of each of the two corners of the electrode. The corner support can support the inner side of the corner to prevent the corner of the electrode from sagging due to the opening.

[0032] According to one embodiment of the invention, a portion of the edge of the opening defined by the corner support may be spaced apart from the edge of the electrode by a predetermined distance or less. For example, the opening may have a curved shape including a first extension extending along the length direction of the electrode and a second extension extending along the width direction of the electrode.

[0033] The vision gripper may comprise a synthetic resin material. According to one embodiment of the invention, the vision gripper may comprise an acrylic resin or polymethyl methacrylate (PMMA) material. To prevent scratches on the vision gripper, it may be made of a high-hardness material such as tempered glass, which could lead to durability or cost issues. However, according to the invention, because of the provided openings and the elimination of concerns about scratches, the vision gripper can be manufactured using a durable and economical synthetic resin material.

[0034] The present invention also provides an electrode inspection method using the electrode inspection device.

[0035] The electrode inspection method includes the following steps in sequence: a clamping step, in which a visual clamp moves up and down and clamps one end of the electrode from above and below; an imaging step, in which a camera captures the region of interest; and a release step, in which the visual clamp moves up and down and releases the electrode.

[0036] During the shooting process, the vision holder can move together with the electrodes at the same speed as the electrodes are moved through the transport device.

[0037] Furthermore, during the clamping and releasing steps, the vision gripper can move up and down to clamp or release the electrode while moving with the electrode at the same speed as the electrode is moved through the transport device.

[0038] Here, the electrode inspection method may further include the following steps: a determination step, determining whether the electrode has defects.

[0039] In the determination step, it can be determined whether there are defects in the width of the electrode. Here, since the two ends of the electrode in the width direction are identifiable in the area where the opening is provided, the width of the electrode can be accurately identified without identification errors caused by scratches due to the accumulation of active material.

[0040] Furthermore, the electrode includes an electrode tab protruding from one end of the electrode, and in the determining step, at least one of the following can be determined: whether there is a defect in the position of the electrode tab relative to the two corners of the electrode; and whether there is a defect in the width of the electrode tab. Here, since the visual gripper is made of a transparent material, the two ends of the electrode tab in the width direction can be accurately identified, and since the visual gripper has an opening, the two ends of the electrode in the width direction can be accurately identified without identification error, thereby accurately identifying the width and position of the electrode tab.

[0041] The present invention also provides a battery manufacturing process including the electrode inspection method described above.

[0042] The battery manufacturing process includes the following steps: a cutting step, cutting metal foil material to form electrodes; an inspection step, performing the electrode inspection method to determine whether the electrodes have defects; and a loading step, loading the electrodes into a cassette when the electrodes are determined to be defect-free products in the inspection step.

[0043] According to one embodiment of the present invention, the size of the electrode can be accurately checked by holding the electrode with a vision clamp, even when the electrode is most prone to sagging or warping immediately after the cutting step.

[0044] Beneficial effects

[0045] The present invention provides an electrode inspection apparatus and method capable of accurately detecting dimensional defects in electrodes, wherein the electrodes are clamped to prevent them from sagging or warping, while preventing over-detection of defects caused by scratches from friction with the electrodes or by active materials.

[0046] The present invention can also provide an electrode inspection device and an electrode inspection method using the electrode inspection device, which can move laterally together with the delivered electrode and quickly and accurately visually inspect the electrode.

[0047] The present invention can also provide a battery manufacturing process in which dimensional defects of the electrodes can be accurately detected during the process of cutting and supplying electrodes for lamination.

[0048] Furthermore, the present invention may have various other effects, and their descriptions will be given in various embodiments, or descriptions of effects that can be easily inferred by those skilled in the art will be omitted. Attached Figure Description

[0049] Figure 1 The electrode after cutting is shown.

[0050] Figure 2 and Figure 3 Clamping for visual inspection is shown Figure 1 The process of electrode fabrication.

[0051] Figure 4 The image shown is from an experiment conducted to check the size of the electrodes.

[0052] Figure 5 The image shown is from an inspection of the corners of the electrodes.

[0053] Figure 6 This is a flowchart illustrating the electrode manufacturing process according to an embodiment of the present invention.

[0054] Figure 7 and Figure 8 The electrodes are shown before and after the cutting step according to an embodiment of the present invention.

[0055] Figure 9 This is a flowchart illustrating a method for inspecting the size of an electrode according to an embodiment of the present invention.

[0056] Figure 10 and Figure 11 The procedure for performing the first check according to an embodiment of the present invention is shown.

[0057] Figure 12 and Figure 13 An image taken for electrode size inspection according to an embodiment of the present invention is shown.

[0058] Figure 14 This is a flowchart illustrating a corner inspection method for electrodes according to an embodiment of the present invention.

[0059] Figure 15 Images taken for corner inspection of electrodes during a first inspection according to an embodiment of the present invention are shown, and Figure 16 The image shown is an image taken for corner inspection of the electrodes during a second inspection according to an embodiment of the present invention.

[0060] Figure 17 This is a schematic diagram illustrating the second step of the corner inspection of the electrodes according to this invention.

[0061] [Explanation of reference numerals in the attached figures]

[0062] 1: Electrode

[0063] 10: Electrode

[0064] 11: Uncoated areas

[0065] 12: Coated area

[0066] 13: Insulation layer (insulating material)

[0067] 2: Visual gripper

[0068] 200: Opening

[0069] 201: First Extension

[0070] 202: Second Extension

[0071] 203: Corner Support

[0072] 21: Upper clamp

[0073] 22: Lower clamp

[0074] 3: Camera

[0075] 4: Conveying device

[0076] R1: Region of First Interest

[0077] R2: Second region of interest

[0078] S: Scratches

[0079] C: Warping

[0080] I1: Image of the product to be inspected

[0081] I2: Image of a defect-free product

[0082] B: Background image

[0083] D1: Electrode width

[0084] D2: Wide shoulders and ears

[0085] D3: Electrode width Detailed Implementation

[0086] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, enabling those skilled in the art to implement the technical concept of the invention. In describing the invention, detailed descriptions of prior art related to the invention will be omitted where it is determined that such detailed descriptions unnecessarily obscure the spirit of the invention. Preferred embodiments according to the invention will be described in detail below with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar parts.

[0087] Although terms such as "first," "second," etc., are used to describe various elements, these elements are certainly not limited by these terms. These terms are only used to distinguish one element from another, and unless otherwise specified, the first element can also be the second element.

[0088] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0089] In the following text, "arranging the component above (or below) the component" or "arranging the component on top (or bottom) of the component" means not only "arranging the component in contact with the upper (or lower) surface", but also "arranging the component above the upper (or lower) surface when another component is in between".

[0090] Furthermore, when describing an element as “connected to,” “linked to,” or “in contact with” another element, it should be understood that the element may be directly “connected to,” “linked to,” or “in contact with” the other element, or that the element may be “connected to,” “linked to,” or “in contact with” another element in between or via another element.

[0091] The singular forms used herein include the plural forms unless the context clearly specifies otherwise. Terms such as “consisting of” or “comprising” as used herein should not be construed as necessarily including all elements or steps described in the specification, but rather as excluding certain elements or steps, or including additional elements or steps.

[0092] Throughout this specification, unless otherwise specified, “A and / or B” means A, B, or A and B, and unless otherwise specified, “C to D” means from equal to or higher than C to equal to or lower than D.

[0093] Preferred embodiments of the invention will be described below with reference to the accompanying drawings.

[0094] [Battery manufacturing process]

[0095] In the following text, reference will be made to Figures 6 to 8 A battery manufacturing process according to an embodiment of the present invention is described. This embodiment exemplifies a battery manufacturing process through a zigzag stacking process, in which anodes and cathodes are alternately inserted and stacked between layers of a zigzag-folded separator. However, it should be clearly understood from the following description that the battery manufacturing process according to the present invention is not limited to this and may include all types of processes including cutting electrodes and supplying them for stacking.

[0096] Figure 6 This is a flowchart illustrating an electrode manufacturing process according to an embodiment of the present invention. (Reference) Figure 6According to an embodiment of the present invention, the battery manufacturing process includes: a cutting step S11, cutting metal foil material to form an electrode; a first inspection step S12, determining whether the electrode has defects; a loading step S13, loading the electrode into a cassette when the electrode is determined to be a defect-free product in the first inspection step; a second inspection step S14, determining whether the electrode has defects; and a supply step S15, supplying the electrode to a stacking device when the electrode is determined to be a defect-free product in the second inspection step. Thereafter, the electrodes can be assembled to form an electrode assembly (S16).

[0097] Figure 7 and Figure 8 The electrodes are shown before and after the cutting step according to an embodiment of the present invention. (Reference) Figure 7 and Figure 8 The electrode 1 before cutting may include: a coated region 12 coated with an active material; and an uncoated region 11, which is not coated with an active material and extends along one end of the electrode 1. The electrode 1 may also be provided with an insulating material 13, which is coated to cover the boundary between the coated region 12 and the uncoated region 11. The insulating material 13 may be partially coated on the uncoated region 11, and the remainder may be coated on the coated region 12.

[0098] In cutting step S11, electrode 1 can be cut to form a tab 10 protruding from one end. Here, electrode 1 can be cut such that the portion of said one end other than the tab 10 protruding therefrom is covered by insulating material 13. That is, electrode 1 can be cut such that the coated area 12 or uncoated area 11 of the portion of said one end other than the tab 10 protruding therefrom is not exposed and is covered by insulating material 13.

[0099] The cutting step S11 can be performed using a laser cutting method. However, the cutting step S11 can be performed using any other cutting method suitable for cutting the metal foil material into the desired shape. Regardless of the cutting method used in the cutting step S11, the electrode 1 is likely to deform immediately after the cutting step S11 due to loads such as heat or friction.

[0100] [Methods for Inspecting Electrode Dimensions]

[0101] In the following text, reference will be made to Figures 9 to 13 A method for inspecting the dimensions of an electrode according to an embodiment of the present invention is described in detail. The method for inspecting the dimensions of an electrode according to this embodiment is characterized by the structure of a visual clamp that holds one end of the electrode from above and below.

[0102] Refer again Figure 6 The electrode size inspection method according to this embodiment can be performed as part of the first inspection step S12.

[0103] Figure 9 This is a flowchart illustrating a method for inspecting the dimensions of an electrode according to an embodiment of the present invention. (Reference) Figure 9 The electrode size inspection method according to an embodiment of the present invention includes, in sequence: a clamping step S21, in which a visual clamp moves up and down and clamps one end of the electrode from above and below the electrode; an imaging step S22, in which a camera captures the region of interest; and a release step S23, in which the visual clamp moves up and down and releases the electrode.

[0104] Figure 10 and Figure 11 The procedure for performing a first inspection according to an embodiment of the present invention is shown. (Reference) Figure 10 and Figure 11 An electrode inspection apparatus for performing an electrode size inspection method includes: a transport device 4 for transporting an electrode 1; a transparent visual gripper 2 for gripping one end of the electrode 1; and a camera 3 for capturing a predetermined first region of interest R1 while the visual gripper 2 grips the one end of the electrode 1, the first region of interest R1 including the two corners of the one end of the electrode 1.

[0105] The vision gripper 2 includes an upper gripper 21 and a lower gripper 22, which are capable of moving up and down from above and below the electrode 1.

[0106] The conveying device 4 can convey electrode 1 while simultaneously conveying a portion of electrode 1 that is adsorbed onto it and spaced inwards from the edge of electrode 1 at a predetermined distance. Here, the edge of electrode 1 may undergo deformation such as drooping or warping. In particular, since electrode 1 has just been cut, the likelihood of drooping or warping is greater. Here, the visual gripper 2 can hold said end of electrode 1, allowing electrode 1 to be photographed in a flat, unfolded state.

[0107] The vision gripper 2 can move together with the electrode 1 at the same speed as the electrode 1 is moved via the transport device 4. That is, return to reference. Figure 9 In the shooting step S22, the vision holder 2 can move together with the electrode 1 at the same speed as the electrode 1 is moved by the conveying device 4.

[0108] Return to reference Figure 10 and Figure 11 Preferably, the vision gripper 2 is configured to move up and down simultaneously with the electrode 1 at the same speed as the electrode 1 is moved through the conveying device 4 to grip or release the electrode 1. Therefore, electrode size inspection is performed concurrently with the conveying of the electrode 1, enabling high-speed production of the electrode 1 and defect inspection.

[0109] That is, return to reference. Figure 9In the clamping step S21 and the releasing step S23, the vision gripper 2 can move up and down to clamp or release the electrode 1 while moving together with the electrode 1 at the same speed as the electrode 1 is moved through the conveying device 4.

[0110] Here, since both electrode 1 and vision holder 2 move laterally and come into contact with each other, scratches may be generated on electrode 1 or vision holder 2. In particular, when active material powder accumulates on these scratches, the edge of electrode 1 may be inaccurately identified, which may lead to over-detection of defects.

[0111] To prevent this, at least one of the upper clamp 21 and the lower clamp 22 according to an embodiment of the present invention is provided with an opening 200 that exposes a predetermined area including two corners of the one end of the electrode 1.

[0112] A pair of openings 200 can be respectively provided in two parts corresponding to the two corners of electrode 1.

[0113] Preferably, the opening 200 is provided at least in the upper clamp 21. Therefore, the two corners of the electrode 1 can be photographed without being covered by the visual clamp 2, and the active material will not accumulate in the scratches in the visual clamp 2 corresponding to the two corners of the electrode 1, thereby allowing for accurate identification of the edges of the electrode 1.

[0114] Furthermore, preferably, the opening 200 is at least provided in the lower gripper 22. In this case, the active material powder generated by the friction between the vision gripper 2 and the electrode 1 can be discharged downward through the opening 200, and recognition errors caused by the accumulation of active material powder can be prevented.

[0115] Preferably, the opening 200 includes a region that does not overlap with the electrode 1. That is, since the opening 200 is a region that is not covered by the electrode 1 and is completely open in the vertical direction, the discharge of the active material powder can be smoother.

[0116] Figure 12 and Figure 13 Images taken for electrode size inspection according to an embodiment of the present invention are shown. (Reference) Figure 12 and Figure 13 According to an embodiment of the present invention, the opening 200 can be provided in both the upper clamp 21 and the lower clamp 22. Therefore, the upper clamp 21 will not be scratched by the electrode 1, and the active material powder can be discharged through the opening of the lower clamp 22.

[0117] Here, the upper clamp 21 and the lower clamp 22 may define a portion of the edge of the opening 200 and may include corner supports 203 that support the inner portion of each of the two corners of the electrode 1. The corner supports 203 protrude toward the two corners to clamp and support the inner portions of the two corners of the electrode 1 from above and below, thereby minimizing the sagging or warping of the two corners in the opening 200.

[0118] According to this embodiment, the opening 200 may have a curved shape, which includes a first extension 201 extending along the length direction of the electrode 1 and a second extension 202 extending along the width direction of the electrode 1. Here, the corner support 203 may be a corner forming the inner edge of the opening 200 extending along the width and length directions.

[0119] Preferably, the corner support 203 is spaced at a predetermined distance or less from the edge of the electrode 1 so as to adequately support the two corners of the electrode 1.

[0120] The vision holder 2 may comprise a synthetic resin material. According to one embodiment of the invention, the vision holder 2 may comprise an acrylic resin or polymethyl methacrylate (PMMA) material. To prevent scratches on the vision holder 2, it may be made of a high-hardness material such as tempered glass, but this could lead to durability or cost issues. However, according to the invention, since the opening 200 is provided and there is no need to worry about scratches on the vision holder 2, it can be manufactured using a durable and economical synthetic resin material.

[0121] Return to reference Figure 9 as well as Figure 13 The electrode size inspection method according to this embodiment may further include a determination step for determining defects in electrode 1.

[0122] In the determination step, defects in the width D3 of electrode 1 can be determined. Here, since both ends of electrode 1 in the width direction are identifiable in the area where the opening 200 is provided, the width D3 of electrode 1 can be accurately identified without identification errors caused by active material accumulated in the scratches.

[0123] Furthermore, in the determination step, at least one of the following can be determined: whether there is a defect in the position of the tab 10 relative to the two corners of the electrode 1; and whether there is a defect in the width of the tab 10. Specifically, in the determination step, the tab width D1 and the tab shoulder width D2 (i.e., the distance from the end of the electrode 1 in the width direction to the tab 10) can be measured. Here, since the visual gripper 2 is made of transparent material, the two ends of the tab 10 in the width direction can be accurately identified, and since the visual gripper 2 has an opening 200, the two ends of the electrode 1 in the width direction can be accurately identified without identification error, and the tab width D1 and the tab shoulder width D2 can be accurately identified.

[0124] [Electrode Corner Inspection Method]

[0125] In the following text, reference will be made to Figures 14 to 17 A detailed description of the corner inspection method for electrodes according to this embodiment is provided. The invention is characterized by determining electrode defects based on a similarity score determined by comparing an image of the product to be inspected obtained by photographing the electrode with pre-learned images of defect-free and / or defective products.

[0126] Return to reference Figure 6 The electrode corner inspection method according to this embodiment can be performed as part of at least one of the first inspection step S12 and the second inspection step S14, and preferably can be included in both the first inspection step S12 and the second inspection step S14.

[0127] Figure 14 This is a flowchart illustrating a method for inspecting the corners of an electrode according to an embodiment of the present invention. (Reference) Figure 14 The corner inspection method for electrodes according to an embodiment of the present invention includes, in sequence: a first step S31, capturing an image of a product to be inspected by photographing a predetermined second region of interest including the corner of the electrode; a second step S33, using an image processing device that has learned images of defect-free products to determine the similarity between the image of the product to be inspected and the image of the defect-free product; and a third step, determining the defects of the electrode based on the similarity.

[0128] Figure 15 Images taken for corner inspection of electrodes during a first inspection according to an embodiment of the present invention are shown, and Figure 16 Images taken for corner inspection of electrodes during a second inspection according to an embodiment of the present invention are shown. (Reference) Figure 15 and Figure 16Since the corner of electrode 1 is part of the uncoated area 11 without active material, the corner of electrode 1 is prone to deformation or damage. Therefore, it is necessary to detect defects caused by deformation or damage. Therefore, the corner inspection method of electrode according to this embodiment detects deformation or damage by photographing the corner of electrode 1.

[0129] To achieve this objective, in the first step S31, preferably, the first region of interest R2 includes at least one corner of the uncoated region 11.

[0130] Preferably, the first region of interest R2 also includes a portion of the background where the electrode 1 is placed and photographed. This is because it is necessary to identify the shape of the corners of the electrode 1.

[0131] In the first step S31, a predetermined background image B can be captured together with the electrode 1 on the background of the electrode 1. Therefore, the image I1 of the product to be inspected can be acquired simultaneously as a single image including the corner of the electrode 1 and the background image B.

[0132] Background image B must have a pre-known shape or color scheme, similar to screen adjustment images. Specifically, background image B can be an image with at least one of known brightness, contrast, saturation, and hue. As described below, background image B can be a standard used to correct the image I1 of the product to be inspected by homogenizing the image I1 of the product to be inspected relative to the image of the defect-free product, so that the image I1 of the product to be inspected can be compared with the image of the defect-free product regardless of the shooting conditions.

[0133] Figure 17 This diagram schematically illustrates the second step of corner inspection of an electrode according to an embodiment of the present invention. (Reference) Figure 17 Preferably, the processing device learns multiple images I2 of defect-free products. Therefore, only the portion relevant to the determination of defects in electrode 1 can be reflected in the defect determination, without being affected by various peripheral secondary factors that may cause differences between images of electrodes that can be considered defect-free products.

[0134] Here, according to this embodiment, in the second step S33, a similarity can be determined for each of the multiple images I2 of defect-free products, thereby obtaining multiple similarities.

[0135] According to the modified example, in the second step S33, the similarity can be a comprehensive single similarity between multiple images I2 of defect-free products and the image I1 of the product to be inspected.

[0136] In the second step S33, preferably, at least one of alignment, brightness, contrast, saturation, and hue is not reflected in the determination of the similarity between the image I2 of the defect-free product and the image I1 of the product to be inspected. This is to compensate for the fact that the shooting conditions of the image I1 of the product to be inspected may differ from those of the image I2 of the defect-free product due to physical variables such as lighting or angle.

[0137] For example, according to one embodiment of the present invention, between the first step S31 and the second step S33, an image correction step S32 may be included to correct the image I1 of the product to be inspected, thereby homogenizing at least one of the alignment, brightness, contrast, saturation and hue of the image I2 of the defect-free product and the image I1 of the product to be inspected.

[0138] Specifically, to achieve this objective, correction can be performed based on at least one of the brightness, contrast, saturation, and hue of the background image B shown in the image I1 of the product to be inspected. The image correction step S32 can be performed in such a way that at least one of the brightness, contrast, saturation, and hue of the image I1 of the product to be inspected is adjusted so that at least one of the brightness, contrast, saturation, and hue of the background image B shown in the image I1 of the product to be inspected becomes the same as a known value.

[0139] According to another embodiment of the present invention, in the second step S33, the image I1 of the product to be inspected can be compared with the image of a defective product but not the image of a product without defects, thereby determining the similarity between the image I1 of the product to be inspected and the image of the defective product. Accordingly, the defect type of electrode 1 can be identified based on which image of the defective product has the highest similarity to the image I1 of the product to be inspected, thus allowing the type of defect to be detected to be specified from the outset, and simultaneously detecting both the presence and type of defect.

[0140] Here, it is also desirable for the processing device to pre-learn images of multiple defective products. Furthermore, the images of these multiple defective products can be images of electrodes all having the same type of defect, or images of electrodes with different defects. The former can be used to target and detect a specific type of defect, while the latter can be used to identify the defect type of electrode 1 based on which image of the product to be inspected has the highest similarity.

[0141] Return to reference Figure 14According to an embodiment of the present invention, the third step can be performed in a manner that determines a product as defect-free when the similarity is greater than or equal to a predetermined value, and determines a product as defective when the similarity is less than or equal to a predetermined value. In other embodiments of the present invention that use an image of a defective product instead of an image of a product as defect-free, the determination can be performed in a manner that determines a product as defect-free when the similarity is less than or equal to a predetermined value, and determines a product as defective when the similarity is greater than or equal to a predetermined value.

[0142] According to the inspection method of the present invention, there is no particular limitation on the type of defect to be detected in electrode 1, as long as the defect is visually or optically identifiable.

[0143] According to one embodiment of the invention, in the third step, the deformation of electrode 1 can be determined. The deformation of electrode 1 can include various deformations that can be considered defects (such as folding, tearing, and wrinkling). To achieve this, the image of a defect-free product can be an image of an electrode without such deformation.

[0144] Furthermore, in the third step, the peeling of the coating on the insulating material 13 can be determined. To achieve this, the image of a defect-free product can be an image of an electrode without coating peeling.

[0145] According to one embodiment of the present invention, in the third step, the presence of a defect in electrode 1 can be determined based on the sum or average of the plurality of similarities. In this case, it is possible to prevent the local similarity or difference between a specific image in a plurality of defect-free product images I2 and the image I1 of the product to be inspected from excessively influencing the determination result.

[0146] Alternatively, in the third step, the defect of electrode 1 can be determined based on the maximum value among the plurality of similarities, thereby preventing over-detection of defects in electrode 1.

[0147] Alternatively, in the third step, the defect of electrode 1 can be determined based on the minimum of the plurality of similarities, thereby minimizing the likelihood of a defective product passing inspection.

[0148] It should be understood that the described embodiments are exemplary and not restrictive in all respects, and the scope of the invention will be indicated by the following claims rather than the detailed description described. Furthermore, the meaning and scope of the claims to be described, as well as all changes and modifications derived from equivalent concepts, should be interpreted as being included within the scope of the invention.

[0149] Although the invention has been described with reference to exemplary accompanying drawings, it should be understood that the invention is not limited to the embodiments and drawings disclosed in this specification, and those skilled in the art will understand that various modifications can be made without departing from the scope and concept of the invention. Furthermore, although the operational effects of the configuration according to the invention are not explicitly described in the description of embodiments of the invention, it should be understood that the predictable effects of this configuration are also recognized.

Claims

1. An electrode inspection device, the electrode inspection device being used to visually inspect the electrode for defects by photographing the electrode, the electrode inspection device comprising: A conveying device that conveys the electrode; A transparent visual gripper for gripping one end of the electrode; as well as A camera, configured to capture images of predetermined regions of interest including two corners of one end of the electrode when the vision holder clamps the electrode. The vision gripper includes an upper gripper and a lower gripper, which move vertically and clamp the electrode from above and below the electrode. At least one of the upper gripper and the lower gripper includes an opening that exposes a predetermined area containing the two corners of one end of the electrode.

2. The electrode inspection device according to claim 1, wherein, The conveying device adsorbs and conveys portions spaced inward from the edge of the electrode at a predetermined distance.

3. The electrode inspection device according to claim 1, wherein, The vision gripper moves together with the electrode at the same speed as the electrode is moved through the transport device.

4. The electrode inspection device according to claim 3, wherein, The vision gripper moves up and down to grip or release the electrode while moving together with the electrode at the same speed as the electrode is moved through the transport device.

5. The electrode inspection device according to claim 1, wherein, The electrode includes a coated area with active material and an uncoated area along one end where no active material is coated. The opening exposes at least a portion of the boundary between the coated area and the uncoated area.

6. The electrode inspection device according to claim 1, wherein, The opening is provided at least in the lower clamp.

7. The electrode inspection device according to claim 6, wherein, The opening includes a region that does not overlap with the electrode.

8. The electrode inspection device according to claim 1, wherein, The opening is provided on both the upper clamp and the lower clamp, and The upper clamp and the lower clamp define a portion of the edge of the opening and include corner supports that support the inner portions of the two corners of the electrode.

9. The electrode inspection device according to claim 8, wherein, A portion of the edge of the opening defined by the corner support is spaced apart from the edge of the electrode by a predetermined distance or less.

10. The electrode inspection device according to claim 1, wherein, The opening includes a first extension extending along the length direction of the electrode and a second extension extending along the width direction of the electrode.

11. The electrode inspection device according to claim 1, wherein, The vision gripper is made of synthetic resin material.

12. The electrode inspection apparatus according to claim 11, wherein, The vision gripper comprises acrylic resin or polymethyl methacrylate (PMMA) material.

13. An electrode inspection method using the electrode inspection apparatus according to claim 1, the electrode inspection method comprising the following steps in sequence: In the clamping step, the vision clamp moves up and down and clamps one end of the electrode from above and below the electrode; The shooting steps involve the camera capturing the area of ​​interest. as well as In the release step, the vision gripper moves up and down and releases the electrodes.

14. The electrode inspection method according to claim 13, wherein, During the shooting step, the vision holder moves together with the electrode at the same speed as the electrode is moved by the transport device.

15. The electrode inspection method according to claim 14, wherein, In the clamping and releasing steps, the vision gripper moves up and down with the electrode at the same speed as the electrode is moved through the transport device to clamp or release the electrode.

16. The electrode inspection method according to claim 13, further comprising the following steps: The steps are determined to determine whether the electrode has defects.

17. The electrode inspection method according to claim 16, wherein, In the determining step, it is determined whether there is a defect in the width of the electrode.

18. The electrode inspection method according to claim 16, wherein, The electrode includes an electrode tab protruding from one end of the electrode, and In the determining step, at least one of the following is determined: whether there is a defect in the position of the electrode tab relative to the two corners of the electrode; and whether there is a defect in the width of the electrode tab.

19. A battery manufacturing process comprising the electrode inspection method according to claim 13, the battery manufacturing process comprising the following steps: The cutting step involves cutting the metal foil material to form electrodes; The inspection step involves performing the electrode inspection method to determine whether the electrode has defects. as well as In the loading step, when the electrode is determined to be a defect-free product in the inspection step, the electrode is loaded into the material box.

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