Electrode inspection apparatus

Abstract

The present invention provides: a structure of an electrode inspection apparatus for photographing an electrode to vision-inspect whether the electrode is defective, the electrode inspection apparatus comprising a transparent vision gripper for gripping one end part of the electrode, wherein the vision gripper has an opening part formed to expose a predetermined region including two corner parts of the one end part of the electrode; and an electrode inspection method for inspecting whether an electrode is defective by using the apparatus.

Description

Electrode testing device

[0001] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0047642, dated April 8, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an inspection device for inspecting electrodes and an electrode inspection method utilizing the same. More specifically, the present invention relates to a vision inspection device for inspecting cut electrodes for dimensional defects, an inspection method utilizing the same, and a battery manufacturing process including the same.

[0003] Secondary batteries, which boast high electrical properties such as high energy density and easy applicability across a wide range of product groups, are widely used not only in portable devices but also in electric or hybrid vehicles powered by electrical power sources, as well as in power storage devices. These batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency, not only because they can dramatically reduce fossil fuel use, but also because they produce no byproducts from energy use.

[0004] While small mobile devices typically use one or two or three battery cells per device, medium- to large-sized devices, such as automobiles, require high output and large capacity. Therefore, medium- to large-sized battery modules or packs consisting of multiple battery cells electrically connected are used.

[0005] Meanwhile, known types of unit secondary battery cells include cylindrical, prismatic, and pouch-shaped battery cells. Since it is desirable for mid- to large-sized battery modules to be manufactured with as small a size and weight as possible, prismatic and pouch-shaped batteries, which can be stacked with high integration and have a small weight per capacity, are primarily used as battery cells for mid- to large-sized battery modules.

[0006] Among these, pouch-type battery cells have various structures depending on the manufacturing method of the electrode assembly they contain. Recently, in particular, the zigzag stacking method, in which positive and negative electrodes are alternately laminated between each layer of a zigzag-folded separator, is often used to rapidly manufacture high-capacity stacked cells. The manufacturing process for producing such stacked cells includes a cutting step for cutting the electrodes, a loading step for loading them into a magazine, and a step for feeding them into a stacking device and assembling them with the separator.

[0007] Figure 1 shows an electrode after cutting is completed. Referring to this, an electrode (1) generally supplied for stacking electrode assemblies has a holding portion (12) coated with an active material for inducing a battery reaction, a non-coated portion (11) not coated with the active material, and an insulating layer (13) coated at the boundary between the holding portion (12) and the non-coated portion (11) for preventing short circuits.

[0008] These electrodes (1) are laser-cut to have tabs (10) protruding to one side, and the electrodes (1) cut in this way undergo a dimensional inspection step to detect defects in dimensions such as the width and formation position of the tabs (10) and the width of the entire electrode (1) immediately after the cutting step.

[0009] Figures 2 and 3 illustrate a process of gripping the electrode of Figure 1 for vision inspection. Referring to these drawings, the electrode (1) is transported with its central portion adsorbed on a transport device (4) immediately after the cutting step. At this time, in order to accurately perform dimensional inspection without being affected by sagging or curling of the electrode (1), a pair of vision grippers (2) are raised and lowered to grip one end of the electrode (1). The vision gripper (2) is made of a transparent synthetic resin material such as acrylic, and presses one end of the electrode (1) flatly while enabling vision inspection using a camera (3).

[0010] Meanwhile, at this time, the vision gripper (2) moves laterally together with the electrode (1) at the speed at which it is transported by the transport device (4) to grip and release the electrode (1).

[0011] Fig. 4 shows an image taken for dimensional inspection of an electrode. Referring to this, as the vision gripper (2) grips and releases the electrode (1) while moving laterally along the electrode (1), a minute friction is applied in the laterally direction between the vision gripper (2) and the electrode (1), and this friction leaves a scratch (S) on the vision gripper (2) along the moving direction of the electrode (1).

[0012] When friction of the maintenance part (12) accumulates on the scratch (S), the dark-colored active material flows into the scratch (S) in powder form, so that the scratch (S) can form an increasingly clear line. The problem is that the edge of the electrode (1) and the tab (10) cannot be accurately detected due to the scratch (S), and thus, a phenomenon occurs in which a dimensional defect of the electrode (1) is over-detected.

[0013] In addition, the electrode (1) may also undergo a corner inspection step to detect defects due to deformation and / or damage at its vulnerable corners. This corner inspection may be performed immediately after the electrode (1) is cut and / or immediately before it is supplied for stacking.

[0014] Fig. 5 shows an image taken for inspection of a corner of an electrode. Referring to this, in order to detect deformation and / or damage to a corner of the electrode (1), the electrode (1) is photographed and used in a method of detecting the position and formation angle of the corner. In order to determine the exact position and formation angle of the corner, a method of detecting the horizontal and vertical axes forming the corner and detecting their intersection and the angle formed by them is mainly used.

[0015] However, due to the thin thickness of the above-mentioned non-conductive portion (11), even if there is no defect in the electrode (1), a fine curl (C) may occur at the corner of the electrode (1). As the curl (C) occurs, the boundary of the corner becomes blurred due to a shadow, making it difficult to accurately detect the horizontal and vertical axes, and there is a problem that defects at the corner of the electrode (1) are over-detected.

[0016] The present invention was created under the background of the above-mentioned prior art, and its purpose is to provide an electrode inspection device and an electrode inspection method capable of accurately detecting dimensional defects in an electrode.

[0017] Specifically, the present invention aims to provide an electrode inspection device and an electrode inspection method that prevent over-detection of defects due to scratches caused by friction with the electrode while holding the electrode to prevent sagging or curling of the electrode.

[0018] The present invention also seeks to provide an electrode inspection device capable of moving along with a transversely transported electrode and quickly and accurately performing a vision inspection of the electrode, and an electrode inspection method using the same.

[0019] Another technical problem of the present invention is to provide a battery manufacturing process in which dimensional defects of the electrode can be accurately detected during the process of cutting and supplying the electrode for lamination.

[0020] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0021] In order to solve the above problem, the present invention provides a structure of an electrode inspection device that performs vision inspection by photographing an electrode to determine whether there is a defect, the electrode inspection device comprising: a transport device for transporting the electrode; a transparent vision gripper for holding one end of the electrode; and a camera for photographing a predetermined region of interest including both corners of one end of the electrode while the vision gripper is holding the one end of the electrode; wherein the vision gripper includes an upper gripper and a lower gripper configured to be raised and lowered from above and below the electrode, and at least one of the upper gripper and the lower gripper has an opening formed to expose a predetermined region including both corners of one end of the electrode.

[0022] According to the present invention, an electrode inspection device is provided that enables more accurate vision inspection by preventing scratches from occurring in a portion corresponding to a corner of the electrode to be inspected for defects in the vision gripper.

[0023] The above-mentioned transport device can transport by adsorbing a portion spaced inward from the edge of the electrode by a predetermined distance. At this time, the edge of the electrode may be deformed to sag downward or roll upward, and the vision gripper can capture the electrode in a flat, spread-out state by holding one end of the electrode.

[0024] The vision gripper may be configured to move in sync with the speed at which the electrode is transported by the transport device. Specifically, according to one embodiment of the present invention, it is preferable that the vision gripper be configured to move in sync with the speed at which the electrode is transported by the transport device while simultaneously ascending and descending to grip or release the electrode. Accordingly, the vision inspection can be performed simultaneously with the transport of the electrode, enabling the electrode to be produced at a high speed and inspected for defects.

[0025] At this time, since both the electrode and the vision gripper move laterally and come into contact, damage that may occur to the electrode or the vision gripper can be prevented by providing the opening.

[0026] The electrode includes a holding portion coated with an active material and a non-coated portion along one end of the electrode, wherein the opening portion can expose at least a portion of the boundary between the holding portion and the non-coated portion. In this case, scratches caused by the active material can be prevented, and the phenomenon of scratches becoming darker due to accumulation of active material powder can also be prevented.

[0027] The above opening may be provided at least on the lower gripper. In this case, the active material powder generated by friction between the vision gripper and the electrode can be discharged downward through the opening, and recognition errors due to accumulation of the active material powder can be prevented.

[0028] At this time, it is preferable that the opening include a region that does not overlap with the electrode. That is, by including a region that is not blocked by the electrode and is completely penetrated vertically, the discharge of the active material powder can be made smoother.

[0029] According to one embodiment of the present invention, the opening may be provided in both the upper gripper and the lower gripper. Accordingly, the upper gripper is not scratched by the electrode, and the active material powder may be discharged through the opening of the lower gripper. At this time, the upper gripper and the lower gripper may include corner supports that define a portion of the edge of the opening and support the inside of both corners of the electrode. The corner supports may support the inside of the corners to prevent the corners of the electrode from sagging due to the provision of the opening.

[0030] According to one embodiment of the present invention, it is preferable that a portion of the edge of the opening defined by the corner support be spaced apart from the edge of the electrode by a predetermined distance or less. For example, the opening may have a bent shape including a first extension extending along the longitudinal direction of the electrode and a second extension extending along the width direction of the electrode.

[0031] The vision gripper may include a synthetic resin material. According to one embodiment of the present invention, the vision gripper may include an acrylic resin or a polymethyl methacrylate (PMMA) material. In order to prevent scratches on the vision gripper, if the material of the vision gripper is made of a material having high hardness such as tempered glass, there may be durability or cost issues. However, according to the present invention, since the opening is provided, there is no concern about scratches occurring on the vision gripper, so it is possible to form the vision gripper of a durable and economical synthetic resin material.

[0032] The present invention also provides an electrode inspection method using the electrode inspection device.

[0033] The above electrode inspection method sequentially includes: a gripping step in which the vision gripper ascends and descends and grips one end of the electrode up and down; a photographing step in which the camera photographs the region of interest; and a gripping release step in which the vision gripper ascends and descends and releases the electrode.

[0034] In the above shooting step, the vision gripper can move together with the electrode at a speed at which the electrode is transported by the transport device.

[0035] Additionally, in the gripping step and the gripping release step, the vision gripper can be raised or lowered to grip or release the electrode, and can move together at the speed at which the electrode is transported by the transport device.

[0036] At this time, the electrode inspection method may additionally include a judgment step for judging whether the electrode is defective.

[0037] In the above judgment step, whether the width of the electrode is defective can be determined. At this time, since the widthwise ends of the electrode are identifiable within the area where the opening is provided, the width of the electrode can be accurately recognized without recognition errors due to scratches or accumulation of active material.

[0038] In addition, the electrode includes an electrode tab protruding from one end of the electrode, and in the judgment step, at least one of whether the formation position of the electrode tab with respect to both corners of the electrode is defective and whether the width of the electrode tab is defective can be determined. At this time, since the vision gripper is formed of a transparent material, both ends of the tab in the width direction can be accurately recognized, and since the vision gripper has the opening, both ends of the electrode in the width direction can be accurately recognized without a recognition error, and thus the width of the electrode tab and the formation position of the electrode tab can be accurately recognized.

[0039] The present invention also provides a battery manufacturing process including the electrode inspection method.

[0040] The above battery manufacturing process includes: a cutting step for cutting a metal foil to form the electrode; an inspection step for performing the electrode inspection method to determine whether the electrode is defective; and a loading step for loading the electrode into a magazine if the electrode is determined to be a good product in the inspection step.

[0041] According to one embodiment of the present invention, even immediately after the cutting step when the electrode is most vulnerable to folding or curling, the vision gripper can accurately inspect the dimensions of the electrode by holding the electrode.

[0042] The present invention provides an electrode inspection device and an electrode inspection method capable of accurately detecting dimensional defects of an electrode, wherein the electrode is held to prevent sagging or curling of the electrode, while preventing over-detection of defects due to scratches or smearing of active materials caused by friction with the electrode.

[0043] The present invention also provides an electrode inspection device that moves along with a transversely transported electrode and can quickly and accurately perform a vision inspection of the electrode, and an electrode inspection method using the same.

[0044] The present invention can also provide a battery manufacturing process in which dimensional defects in the electrode can be accurately detected during the process of cutting and supplying the electrode for lamination.

[0045] In addition, the present invention may have various other effects, which will be described in each embodiment, or the description of effects that can be easily inferred by a person skilled in the art will be omitted.

[0046] Figure 1 shows an electrode after cutting is completed.

[0047] Figures 2 and 3 illustrate the process of gripping the electrode of Figure 1 for vision inspection.

[0048] Figure 4 shows an image taken for dimensional inspection of the electrode.

[0049] Figure 5 shows an image taken to inspect the corner of the electrode.

[0050] Figure 6 is a flowchart showing an electrode manufacturing process according to one embodiment of the present invention.

[0051] Figures 7 and 8 respectively illustrate electrodes before and after a cutting step according to one embodiment of the present invention.

[0052] Figure 9 is a flowchart showing a method for inspecting the dimensions of an electrode according to one embodiment of the present invention.

[0053] Figures 10 and 11 illustrate a process of performing a first inspection according to one embodiment of the present invention.

[0054] Figures 12 and 13 show images taken for dimensional inspection of an electrode according to one embodiment of the present invention.

[0055] Fig. 14 is a flowchart showing a method for inspecting a corner of an electrode according to one embodiment of the present invention.

[0056] FIG. 15 shows an image taken for inspection of a corner of an electrode in a first inspection according to one embodiment of the present invention, and FIG. 16 shows an image taken for inspection of a corner of an electrode in a second inspection according to one embodiment of the present invention.

[0057] Fig. 17 is a schematic diagram showing the second step of inspection of a corner of an electrode according to one embodiment of the present invention.

[0058] [Explanation of symbols]

[0059] 1: Electrode

[0060] 10: Tap

[0061] 11: Ministry of Immigration

[0062] 12: Maintenance Department

[0063] 13: Insulating layer (insulating material)

[0064] 2: Vision Gripper

[0065] 200: Opening

[0066] 201: 1st Extension Section

[0067] 202: Second Extension Department

[0068] 203: Corner support

[0069] 21: Upper gripper

[0070] 22: Lower gripper

[0071] 3: Camera

[0072] 4: Transport device

[0073] R1: First area of ​​interest

[0074] R2: Secondary area of ​​interest

[0075] S: Scratch

[0076] C: Curl

[0077] I1: Image to be inspected

[0078] I2 quality image

[0079] B: Background image

[0080] D1: Tab width

[0081] D2: Tap shoulder width

[0082] D3: Electrode width

[0083] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0084] Although the terms "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0085] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0086] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0087] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0088] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0089] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0090] Hereinafter, a preferred embodiment of the present invention will be described with reference to the attached drawings.

[0091]

[0092] [Battery manufacturing process]

[0093] Hereinafter, with reference to FIGS. 6 to 8, a battery manufacturing process according to an embodiment of the present invention will be described. This embodiment describes a zigzag stacking process in which positive and negative electrodes are alternately stacked between each layer of a separator folded in a zigzag pattern as an example of a battery manufacturing process. However, it will be clearly understood through the following description that the battery manufacturing process according to the present invention is not limited thereto and may include all types of processes including a process of cutting electrodes and supplying them for stacking.

[0094] FIG. 6 is a flowchart illustrating an electrode manufacturing process according to an embodiment of the present invention. Referring to this, the battery manufacturing process according to an embodiment of the present invention includes: a cutting step (S11) of cutting a metal foil to form an electrode; a first inspection step (S12) of determining whether the electrode is defective; a loading step (S13) of loading the electrode into a magazine if the electrode is determined to be a good product in the first inspection step; a second inspection step (S14) of determining whether the electrode is defective; and a supply step (S15) of supplying the electrode to a stacking device if the electrode is determined to be a good product in the second inspection step. Thereafter, the electrodes can be assembled to form an electrode assembly (S16).

[0095] Figures 7 and 8 respectively illustrate electrodes before and after a cutting step according to one embodiment of the present invention. Referring to them, the electrode (1) before cutting may include: a holding portion (12) on which an active material is coated; and a non-coated portion (11) extending along one end of the electrode (1) and not coated with the active material. The electrode (1) may also be provided with an insulating material (13) coated to cover the boundary between the holding portion (12) and the non-coated portion (11). A portion of the insulating material (13) may be coated on the non-coated portion (11) and the remainder may be coated on the holding portion (12).

[0096] In the above cutting step (S11), the electrode (1) may be cut to form a tab (10) protruding from one end thereof. At this time, the electrode (1) may be cut so that the portion excluding the tab (10) at the end where the tab (10) protrudes is covered with the insulating material (13). That is, the electrode (1) may be cut so that the holding portion (12) or the non-woven portion (11) is not exposed as is at one end thereof, but is covered with the insulating material (13) at the portion excluding the tab (10).

[0097] The above cutting step (S11) may be performed using a laser cutting method. However, the above cutting step (S11) may be performed using any other cutting method configured to cut the metal foil into a desired shape. Regardless of the cutting method used for the above cutting step (S11), there is a high possibility that deformation will occur in the electrode (1) immediately after the above cutting step (S11) due to loads such as heat or friction.

[0098]

[0099] [Method for inspecting electrode dimensions]

[0100] Hereinafter, with reference to FIGS. 9 to 13, a method for inspecting the dimensions of an electrode according to an embodiment of the present invention will be described in detail. The method for inspecting the dimensions of an electrode according to the present embodiment is characterized by the structure of a vision gripper that grips one end of the electrode from above and below.

[0101] Referring again to FIG. 6, the method for inspecting the dimensions of an electrode according to the present embodiment can be performed as part of the first inspection step (S12).

[0102] Fig. 9 is a flowchart illustrating a method for inspecting the dimensions of an electrode according to one embodiment of the present invention. Referring to this, the method for inspecting the dimensions of an electrode according to one embodiment of the present invention sequentially includes: a gripping step (S21) in which a vision gripper ascends and descends and grips one end of the electrode up and down; a photographing step (S22) in which a camera photographs a predetermined first region of interest; and a gripping release step (S23) in which the vision gripper ascends and descends and releases the electrode.

[0103] Figures 10 and 11 illustrate a process of performing a first inspection according to one embodiment of the present invention. Referring to these drawings, an electrode inspection device for performing a dimensional inspection method of the electrode includes: a transport device (4) for transporting the electrode (1); a transparent vision gripper (2) for holding one end of the electrode (1); and a camera (3) for photographing a predetermined first region of interest (R1) including both corners of one end of the electrode (1) while the vision gripper (2) is holding one end of the electrode (1).

[0104] The above vision gripper (2) includes an upper gripper (21) and a lower gripper (22) configured to rise and fall from the top and bottom of the electrode (1).

[0105] The above-mentioned transport device (4) can transport by adsorbing a portion spaced inward from the edge of the electrode (1) by a predetermined distance. At this time, deformation such as sagging downward or rolling upward may occur at the edge of the electrode (1). In particular, since the electrode (1) has just been cut at this time, the possibility of rolling or sagging is even greater. At this time, the vision gripper (2) can capture the electrode (1) in a flat, spread-out state by gripping one end of the electrode (1).

[0106] The above vision gripper (2) can be configured to move together with the electrode (1) at the speed at which it is transported by the transport device (4). That is, referring again to Fig. 9, in the photographing step (S22), the vision gripper (2) can move together with the electrode (1) at the speed at which it is transported by the transport device (4).

[0107] Referring again to FIGS. 10 and 11, it is preferable that the vision gripper (2) be configured so that it can move at the same speed at which the electrode (1) is transported by the transport device (4) even while being raised or lowered to grip or release the electrode (1). Accordingly, the electrode dimension inspection can be performed simultaneously with the transport of the electrode (1), thereby producing the electrode (1) at a high speed and inspecting it for defects.

[0108] That is, referring back to FIG. 9, in the gripping step (S21) and the gripping release step (S23), the vision gripper (2) can move up and down to grip or release the electrode (1) while simultaneously moving together at the speed at which the electrode (1) is transported by the transport device (4).

[0109] At this time, since both the electrode (1) and the vision gripper (2) move laterally and come into contact, scratches may occur on the electrode (1) or the vision gripper (2). In particular, if the active material powder accumulates on these scratches, the edge of the electrode (1) may be inaccurately recognized, resulting in over-detection of defects.

[0110] To prevent this, at least one of the upper gripper (21) and the lower gripper (22) according to one embodiment of the present invention has an opening (200) formed to expose a predetermined area including both corners of one end of the electrode (1).

[0111] The above openings (200) can be provided in pairs at locations corresponding to both corners of the electrode (1).

[0112] It is preferable that the above opening (200) be provided at least in the upper gripper (21). Accordingly, both corners of the electrode (1) can be photographed as they are exposed without being covered by the vision gripper (2), and scratches and active material accumulation do not occur in the areas corresponding to both corners of the electrode (1) in the vision gripper (2), so that the edge of the electrode (1) can be accurately recognized.

[0113] In addition, it is preferable that the opening (200) be provided at least in the lower gripper (22). In this case, the active material powder generated by friction between the vision gripper (2) and the electrode (1) can be discharged downward through the opening (200), and recognition errors due to accumulation of the active material powder can be prevented.

[0114] At this time, it is preferable that the opening (200) includes a region that does not overlap with the electrode (1). That is, by including a region in which the opening (200) is not blocked by the electrode (1) and is completely penetrated vertically, the discharge of the active material powder can be made smoother.

[0115] Figures 12 and 13 illustrate images taken for dimensional inspection of an electrode according to one embodiment of the present invention. Referring to these drawings, the opening (200) according to one embodiment of the present invention can be provided in both the upper gripper (21) and the lower gripper (22). Accordingly, scratches caused by the electrode (1) do not occur on the upper gripper (21), and the active material powder can be discharged through the opening of the lower gripper (22).

[0116] At this time, the upper gripper (21) and the lower gripper (22) may define a portion of the edge of the opening (200) and include corner supports (203) that support the inside of both corners of the electrode (1). The corner supports (203) are provided to protrude toward the both corners so as to support the inside of the both corners of the electrode (1) by gripping them up and down, thereby minimizing the phenomenon of the both corners sagging or rolling in the opening (200).

[0117] According to the present embodiment, the opening (200) may have a bent shape including a first extension (201) extending along the longitudinal direction of the electrode (1) and a second extension (202) extending along the width direction of the electrode (1). At this time, the corner support (203) may form a corner constituting the widthwise and lengthwise inner edges of the opening (200).

[0118] At this time, it is preferable that the corner support (203) be spaced apart from the edge of the electrode (1) by a predetermined distance or less so as to sufficiently support both corners of the electrode (1).

[0119] The above vision gripper (2) may include a synthetic resin material. According to one embodiment of the present invention, the vision gripper (2) may include an acrylic resin or a polymethyl methacrylate (PMMA) material. In order to prevent scratches on the vision gripper (2), if the material of the vision gripper (2) is made of a material having high hardness such as tempered glass, there may be durability or cost issues. However, according to the present invention, since the opening (200) is provided, there is no concern about scratches occurring on the vision gripper (2), so it is possible to form the vision gripper (2) of a durable and economical synthetic resin material.

[0120] Referring back to FIG. 9 together with FIG. 13, the method for inspecting the dimensions of an electrode according to the present embodiment may additionally include a judgment step for determining whether the electrode (1) is defective.

[0121] In the above judgment step, it can be determined whether the width (D3) of the electrode (1) is defective. At this time, since both ends of the electrode (1) in the width direction are identifiable within the area where the opening (200) is provided, the width (D3) of the electrode (1) can be accurately recognized without recognition errors due to scratches or accumulation of active material.

[0122] In addition, in the judgment step, at least one of whether the formation position of the tab (10) with respect to both corners of the electrode (1) is defective and whether the width of the tab (10) is defective can be judged. Specifically, in the judgment step, the tab width (D1) and the tab shoulder width (D2), i.e., the widthwise distance from the widthwise end of the electrode (1) to the tab (10), can be measured. At this time, since the vision gripper (2) is formed of a transparent material, both widthwise ends of the tab (10) can be accurately recognized, and since the vision gripper (2) has the opening (200), both widthwise ends of the electrode (1) can be accurately recognized without recognition errors, and the tab width (D1) and the tab shoulder width (D2) can be accurately recognized.

[0123]

[0124] [Method for inspecting the corners of the electrode]

[0125] Hereinafter, with reference to FIGS. 14 to 17, a method for inspecting corners of an electrode according to the present embodiment will be described in detail. The present invention is characterized in that it determines whether the electrode is defective based on a similarity determined by comparing an inspection target image obtained by photographing the electrode with a learned good and / or defective product image.

[0126] Referring again to FIG. 6, the corner inspection method of the electrode according to the present embodiment may be performed as a part of at least one of the first inspection step (S12) and the second inspection step (S14), and preferably may be included in both the first inspection step (S12) and the second inspection step (S14).

[0127] Fig. 14 is a flowchart illustrating a method for inspecting a corner of an electrode according to an embodiment of the present invention. Referring to this, the method for inspecting a corner of an electrode according to an embodiment of the present invention sequentially includes: a first step (S31) of photographing a predetermined second region of interest including one corner of the electrode to obtain an inspection target image; a second step (S33) of determining a similarity between the inspection target image and the good product image using an image processing device that has learned a good product image; and a third step of determining whether the electrode is defective based on the similarity.

[0128] Fig. 15 shows an image photographed for inspecting a corner of an electrode in a first inspection according to an embodiment of the present invention, and Fig. 16 shows an image photographed for inspecting a corner of an electrode in a second inspection according to an embodiment of the present invention. Referring to these drawings, the corner of the electrode (1) belongs to the non-coated portion (11) where the active material is not coated, and is therefore vulnerable to deformation or damage, and therefore, it is necessary to detect defects caused by this. Accordingly, the method for inspecting a corner of an electrode according to the present embodiment is to photograph the corner of the electrode (1) to detect whether it is deformed or damaged.

[0129] To this end, in the first step (S31), it is preferable that the first area of ​​interest (R2) includes at least one corner of the unshaded portion (11).

[0130] It is also preferable to photograph the first region of interest (R2) including a portion of the background where the electrode (1) is placed. This is because it is necessary to identify the shape of the corner of the electrode (1).

[0131] In the above first step (S31), a predetermined background image (B) provided on the background where the electrode (1) is placed can be captured together with the electrode (1). Accordingly, the inspection target image (I1) can be acquired as a single image that simultaneously includes the corner portion of the electrode (1) and the background image (B).

[0132] The above background image (B) must be one whose shape and color scheme are known in advance, just like a screen adjustment image. Specifically, the background image (B) may be an image in which at least one of brightness, contrast, saturation, and color tone is known. As described below, the background image (B) may serve as a standard for correcting the inspection target image (I1) to homogenize the inspection target image (I1) in relation to the good product image, so that the inspection target image (I1) can be compared with the good product image regardless of the shooting conditions.

[0133] Fig. 17 is a schematic diagram illustrating the second step of the corner inspection of an electrode according to one embodiment of the present invention. Referring to this, it is preferable that the processing device learn a plurality of images (I2) of the good product. Accordingly, only the portion related to the defect of the electrode (1) can be reflected in the determination of whether or not the electrode (1) is defective, without being influenced by various peripheral and incidental factors that may differ between images of electrodes that can be considered good products.

[0134] At this time, according to the present embodiment, in the second step (S33), the similarity may be determined as multiple similarities, one for each of the multiple good product images (I2).

[0135] According to one variation, in the second step (S33), the similarity may be determined as a single comprehensive similarity between the plurality of good product images (I2) and the inspection target image (I1).

[0136] In the second step (S33), it is preferable that at least one of alignment, brightness, contrast, saturation, and color tone between the good product image (I2) and the inspection target image (I1) is not reflected in the determination of the similarity. This is to compensate for the fact that the shooting conditions of the inspection target image (I1) may differ from the shooting conditions of the good product image (I2) 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 additionally included for correcting the inspection target image (I1) to homogenize at least one of alignment, brightness, contrast, saturation, and color tone between the good product image (I2) and the inspection target image (I1).

[0138] Specifically for this purpose, the correction may be performed based on at least one of brightness, contrast, saturation, and color tone of the background image (B) appearing in the inspection target image (I1). The image correction step (S32) may be performed in a manner of adjusting at least one of brightness, contrast, saturation, and color tone of the inspection target image (I1) so that at least one of brightness, contrast, saturation, and color tone of the background image (B) appearing in the inspection target image (I1) becomes the same as a known one.

[0139] According to another embodiment of the present invention, in the second step (S33), the inspection target image (I1) can be compared with a defective product image rather than a good product image, and thus the similarity between the inspection target image (I1) and the defective product image can be determined. Accordingly, the type or kind of defect of the electrode (1) can be identified depending on which of the defective product images has a high similarity to the inspection target image (I1), so that the inspection can be performed by specifying the type or kind of defect to be detected from the beginning, and it is also possible to detect the type or kind of defect together with the presence or absence of a defect.

[0140] At this time, it is also preferable that the processing device learn a plurality of defective product images. Furthermore, at this time, the plurality of defective product images may all be images of electrodes having the same type of defect, or may be images of electrodes having different types of defects. The former may be used when targeting and detecting a specific type of defect, and the latter may be used to identify the type of defect the electrode (1) has based on which of the plurality of defective product images the inspection target image (I1) has the highest similarity with.

[0141] Referring back to FIG. 14, the third step according to one embodiment of the present invention may be performed in such a way that a good product is determined when the similarity is greater than or equal to a predetermined value, and a defective product is determined when the similarity is less than or equal to a predetermined value. In another embodiment of the present invention that uses a defective product image instead of the good product image, a good product is determined when the similarity is less than or equal to a predetermined value, and a defective product is determined when the similarity is greater than or equal to a predetermined value.

[0142] The type of defect of the electrode (1) that is the target of detection by the inspection method according to the present invention is not particularly limited as long as it can be visually or optically identified.

[0143] According to one embodiment of the present invention, in the third step, it can be determined whether the electrode (1) is deformed. The deformation of the electrode (1) may include various deformations that may be considered defective, such as folding, tearing, and wrinkling. For this purpose, the image of the good product may be an image of an electrode in which such deformation has not occurred.

[0144] Additionally, in the third step, it can be determined whether the coating of the insulating material (13) has peeled off. For this purpose, the image of the good product may be an image of an electrode in which such coating peeling has not occurred.

[0145] According to one embodiment of the present invention, in the third step, whether the electrode (1) is defective can be determined based on the sum or average of the plurality of similarities. In this case, it is possible to prevent local similarities or differences between a specific image among the plurality of good product images (I2) and the inspection target image (I1) from excessively influencing the determination result.

[0146] Or, at this time, in the third step, whether the electrode (1) is defective or not can be determined based on the maximum value among the plurality of similarities, thereby preventing the defect of the electrode (1) from being over-detected.

[0147] Alternatively, at this time, in the third step, whether the electrode (1) is defective may be determined based on the minimum value among the plurality of similarities, thereby minimizing the possibility of a defective product passing the inspection.

[0148]

[0149] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0150] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. In an electrode inspection device that takes pictures of electrodes and visually inspects them for defects, A transport device for transporting the above electrode; A transparent vision gripper for holding one end of the electrode; and A camera that captures a predetermined region of interest including both corners of one end of the electrode while the vision gripper is holding one end of the electrode; The above vision gripper includes an upper gripper and a lower gripper configured to be lifted from above and below the electrode, An electrode inspection device, wherein at least one of the upper gripper and the lower gripper has an opening formed to expose a predetermined area including both corners of one end of the electrode.

2. In claim 1, An electrode inspection device in which the above-mentioned transfer device absorbs and transfers a portion spaced a predetermined distance inward from the edge of the electrode.

3. In claim 1, An electrode inspection device, wherein the vision gripper is configured to move together with the electrode at a speed at which the electrode is transported by the transport device.

4. In claim 3, An electrode inspection device, wherein the vision gripper is configured to move at a speed at which the electrode is transported by the transport device while being elevated to grip or release the electrode.

5. In claim 1, The electrode includes a maintenance portion coated with an active material and a non-coated portion along the end portion where the active material is not coated, An electrode inspection device wherein the opening exposes at least a portion of the boundary between the maintenance portion and the non-maintenance portion.

6. In claim 1, An electrode inspection device, wherein the above opening is provided at least in the lower gripper.

7. In claim 6, An electrode inspection device, wherein the opening includes an area that does not overlap with the electrode.

8. In claim 1, The above opening is provided in both the upper gripper and the lower gripper, An electrode inspection device, wherein the upper gripper and the lower gripper define a portion of the edge of the opening and include corner supports that support the inside of both corners of the electrode.

9. In claim 8, An electrode inspection device, wherein a portion of the edge of the opening defined by the corner support member is spaced apart from the edge of the electrode by a predetermined distance or less.

10. In claim 1, An electrode inspection device, wherein the opening includes a first extension portion extending along the longitudinal direction of the electrode and a second extension portion extending along the width direction of the electrode.

11. In claim 1, The above vision gripper is an electrode inspection device comprising a synthetic resin material.

12. In claim 11, The above vision gripper is an electrode inspection device comprising an acrylic resin or polymethyl methacrylate (PMMA) material.

13. In an electrode inspection method using the electrode inspection device of claim 1, A gripping step in which the vision gripper ascends and descends and grips one end of the electrode up and down; A photographing step in which the camera photographs the area of ​​interest; and An electrode inspection method, comprising a step of sequentially lifting and releasing the vision gripper and releasing the electrode.

14. In claim 13, An electrode inspection method wherein, in the above photographing step, the vision gripper moves together with the electrode at a speed at which the electrode is transported by the transport device.

15. In claim 14, An electrode inspection method, wherein, in the above-mentioned gripping step and the above-mentioned gripping release step, the vision gripper is raised and lowered to grip or release the electrode, and at the same time moves together at a speed at which the electrode is transported by the transport device.

16. In claim 13, An electrode inspection method further comprising a judgment step of judging whether the electrode is defective.

17. In claim 16, An electrode inspection method in which, in the above judgment step, it is determined whether the width of the electrode is defective.

18. In claim 16, The electrode includes an electrode tab protruding from one end of the electrode, An electrode inspection method, wherein, in the above judgment step, at least one of whether the formation position of the electrode tab with respect to both corners of the electrode is defective and whether the width of the electrode tab is defective is judged.

19. In a battery manufacturing process including the electrode inspection method of claim 13, The above battery manufacturing process is: A cutting step for forming the electrode by cutting the metal foil; An inspection step for determining whether the electrode is defective by performing the above electrode inspection method; and A battery manufacturing process, comprising a loading step of loading the electrode into a magazine if the electrode is judged to be a good product in the inspection step.

Images