Image brightness correction method and electrode inspection apparatus using the same

Abstract

An image brightness correction method according to an embodiment of the present invention may include the steps of: acquiring a plurality of images of the appearance of a target object captured at different brightness levels; extracting one or more inspection target areas from the above images; comparing the brightness of the one or more inspection target areas with a brightness threshold set for each inspection target area; and calculating a brightness correction value by reflecting a target brightness in the brightness of the inspection target areas according to the comparison result.

Description

Technical Field

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2023-0181389, filed with the Korean Intellectual Property Office on December 14, 2023, and all of the content disclosed in the document of the Korean patent application is incorporated herein.

[0002] The present invention relates to an image brightness correction method and an electrode inspection apparatus using the same, and more particularly, to an image brightness correction method for adjusting the brightness of an image of an electrode during a battery electrode process and an electrode inspection apparatus using the same.

Background Art

[0003] A secondary battery is a battery that can be reused through charging even after discharge, and can be used as an energy source for small devices such as mobile phones, tablet PCs, and vacuum cleaners, and can also be used as a medium and large energy source for personal mobility, automobiles, and smart grid ESSs (Energy Storage Systems). Secondary batteries are used in the form of assemblies such as battery modules in which a number of battery cells are connected in series or parallel, or battery packs in which battery modules are connected in series or parallel, according to the requirements of the system.

[0004] A battery can be manufactured through a process including a large electrode process, an assembly process, and an activation / inspection process, and defective point inspection is performed on the manufactured battery cells or the results of each process through inspection equipment. Among the defective point inspection methods, inspection using an image is one of the most commonly used techniques. Image inspection can be performed by acquiring an image of parts and semi-finished products during the process using an optical system and detecting defects using a detection algorithm.

[0005] In this regard, during the electrode slitting process performed in the electrode manufacturing process, the slit width and the presence or absence of defects on the electrode surface are important factors that affect product quality, and image-based quality inspection can be performed. Here, the brightness of the image in the image inspection can directly affect the inspection quality.

[0006] Incidentally, changes in raw materials or process conditions may cause the brightness of the electrode inspection image to fluctuate to an extent that makes normal inspection impossible. In this case, all related manufacturing equipment must be shut down, and then the operator must adjust the lighting intensity or camera exposure value to bring the brightness of the inspection image within the inspectable specification range. Therefore, not only will this result in a decrease in production rate and an increase in production costs due to equipment shutdown, but problems such as over-detection and defective products being released due to manual work may also occur. [Overview of the project] [Problems that the invention aims to solve]

[0007] The objective of the present invention, in order to solve the above-mentioned problems, is to provide an image brightness correction method for adjusting the brightness of an electrode image during the electrode manufacturing process of a battery.

[0008] Another objective of the present invention to solve the above-mentioned problems is to provide an apparatus for inspecting electrodes using the above-described image brightness correction method. [Means for solving the problem]

[0009] An image brightness correction method according to one embodiment of the present invention for achieving the above objective may include the steps of: acquiring a plurality of images of the appearance of a target object captured at different brightness levels; extracting one or more inspection target areas within each image; comparing the brightness of the one or more inspection target areas with a brightness threshold set for each inspection target area; and calculating a brightness correction value by reflecting a target brightness in the brightness of the inspection target areas according to the comparison result.

[0010] The brightness of the inspection area can be set to the average brightness of the pixels within that area.

[0011] The step of comparing the brightness of one or more inspection areas with a brightness threshold set for each inspection area may include the step of comparing the average brightness of the inspection area with a brightness lower limit and brightness upper limit set for that inspection area.

[0012] In accordance with the above comparison results, the step of calculating a brightness correction value by reflecting the target brightness in the brightness of the area to be inspected may include the step of calculating the brightness correction value based on the difference between the average brightness and the target brightness if the average brightness of the area to be inspected is outside the range of the lower brightness limit or the upper brightness limit.

[0013] The step of calculating the brightness correction value based on the difference between the average brightness and the target brightness may include the step of calculating a camera exposure time adjustment value, which is calculated by multiplying the difference between the average brightness and the target brightness by a control constant.

[0014] The step of calculating the brightness correction value based on the difference between the average brightness and the target brightness may include the step of calculating the camera exposure time adjustment value by multiplying the largest of the multiple brightness correction values ​​by a control constant if there are multiple inspection target areas included in a single image and the brightness correction values ​​calculated for the multiple inspection target areas are different from each other.

[0015] The above image brightness correction method may further include the step of providing the calculated camera exposure time adjustment value to the imaging device.

[0016] The above-mentioned target objects may include electrodes in the electrode process of the battery manufacturing process.

[0017] The one or more inspection areas described above may include one or more areas of the electrode that are divided according to the attributes of the area, such as the coated portion, the plain portion, and the insulating portion.

[0018] Multiple images captured at different brightness levels include a first image captured at a first brightness level and a second image captured at a second brightness level, wherein the second brightness level is different from the first brightness level.

[0019] Using the brightness-corrected inspection area described above, defects in the target object during the manufacturing process can be inspected.

[0020] An electrode inspection device for a product according to one embodiment of the present invention for achieving the above-mentioned other objective is a device for inspecting electrodes in the electrode process of a battery manufacturing process, and may include at least one processor; and a memory for storing at least one instruction executed through the at least one processor, wherein the at least one instruction may include an instruction for receiving a plurality of images from an imaging device, each image capturing the appearance of a target object at different brightness levels; an instruction for extracting one or more inspection target areas within each image; an instruction for comparing the brightness of the one or more inspection target areas with a brightness threshold set for each inspection target area; and an instruction for calculating a brightness correction value by reflecting a target brightness in the brightness of the inspection target areas according to the comparison result.

[0021] The brightness of the inspection area can be set to the average brightness of the pixels within that area.

[0022] A command that compares the brightness of one or more inspection areas with a brightness threshold set for each inspection area may include a command that compares the average brightness of an inspection area with a brightness lower limit and brightness upper limit set for that inspection area.

[0023] According to the comparison result, the instruction to calculate the brightness correction value by reflecting the target brightness in the brightness of the inspection target area may include an instruction to calculate the brightness correction value based on the difference value between the average brightness of the inspection target area and the target brightness when the average brightness of the inspection target area is outside the range of the brightness lower limit value to the brightness upper limit value.

[0024] The instruction to calculate the brightness correction value based on the difference value between the average brightness and the target brightness may include an instruction to calculate a camera exposure time adjustment value calculated by multiplying the difference between the average brightness and the target brightness by a control constant.

[0025] The instruction to calculate the brightness correction value based on the difference value between the average brightness and the target brightness may include an instruction to calculate a camera exposure time adjustment value by multiplying the largest value among the plurality of brightness correction values by a control constant when there are a plurality of inspection target areas included in one image and the brightness correction values calculated for the plurality of inspection target areas are different from each other.

[0026] The at least one instruction may further include an instruction to provide the calculated camera exposure time adjustment value to the imaging device.

[0027] The one or more inspection target areas may include one or more areas among the coating part, the plain part, and the insulating part of the electrode divided according to the attributes of the area.

[0028] The plurality of images captured with different brightnesses may include a first image captured with a first brightness and a second image captured with a second brightness, and the second brightness may be different from the first brightness.

[0029] On the other hand, the at least one instruction may further include an instruction to perform a defect inspection of the target object during the process using the brightness-corrected inspection target area.

Effect of the Invention

[0030] According to the embodiments of the present invention described above, in image inspection of battery electrodes, the brightness of the inspection image can be automatically corrected in real time, thereby enabling the quantification and automation of image quality control.

[0031] Furthermore, electrode inspections can be performed without stopping the manufacturing equipment, thus preventing damage caused by equipment downtime.

[0032] Furthermore, it eliminates the risk of over-detection and under-detection due to human error in existing manual processes. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram of a battery manufacturing process to which the present invention can be applied. [Figure 2] This is a conceptual diagram of a slitting process to which the present invention can be applied. [Figure 3a] An example of the inspection area of ​​the electrode inspection device according to an embodiment of the present invention is shown. [Figure 3b] An example of the inspection area of ​​the electrode inspection device according to an embodiment of the present invention is shown. [Figure 4] This is a schematic flowchart of an image brightness correction method according to an embodiment of the present invention. [Figure 5] This is a table showing the inspection items in each image according to the embodiment of the present invention. [Figure 6] This is a table showing the items to be detected through each image inspection according to the embodiments of the present invention. [Figure 7] This figure shows the items to be detected through each image inspection according to the embodiment of the present invention, as actually displayed on the image. [Figure 8] An example of a brightness correction method for images with low brightness according to an embodiment of the present invention is shown. [Figure 9] This is a block diagram of an electrode inspection device according to an embodiment of the present invention. [Modes for carrying out the invention]

[0034] The present invention can be modified in various ways and has many embodiments; therefore, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this should be understood not as limiting the present invention to specific embodiments, but rather as including all modifications, equivalents, or substitutes that fall within the spirit and technical scope of the present invention. Similar reference numerals are used for similar components in the description of each drawing.

[0035] Terms such as First, Second, A, B, etc., may be used to describe various components, but the components shall not be limited by such terms. The terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the First component may be named the Second component, and similarly, the Second component may be named the First component. The terms "and / or" include combinations of multiple items described in relation or one of multiple items described in relation.

[0036] When it is stated that one component is "linked" or "connected" to another component, it should be understood that this may mean that it is directly linked or connected to that other component, but that there may also be another component in between. Conversely, when it is stated that one component is "directly linked" or "directly connected" to another component, it should be understood that there is no other component in between.

[0037] The terms used in this application are used solely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless they are clearly different in context. In this application, terms such as “includes” or “having” are intended to specify the presence of features, figures, steps, actions, components, parts, or combinations thereof as described in the specification, and should not be understood to preemptively exclude the presence or possibility of adding one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0038] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless explicitly defined herein.

[0039] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] Figure 1 is a schematic diagram of a battery manufacturing process to which the present invention can be applied.

[0041] The battery can be manufactured through an electrode process (S10), an assembly process (S20), and an activation / testing process (S30). The completed battery is shipped in the form of a battery pack (or battery module) containing multiple battery cells connected in series. The battery pack can be connected to a load via positive and negative terminals for charging and discharging. The battery pack can be configured in series or parallel depending on the required specifications of the system in which the battery is used.

[0042] More specifically, the electrode process (S10) can proceed in the following order: a "mixing process" in which raw materials are mixed, a "coating process" in which the mixed slurry is applied to foil and dried, a "roll pressing process" in which the electrodes are pressed to reduce their thickness, a "slitting process" in which the electrodes are cut to a predetermined width, and a "notching process" in which tabs are made on the electrodes.

[0043] Here, the slitting process involves cutting the electrodes, which have been thinned through the roll press process, to match the size of the battery. This process uses a slitter to cut the electrodes lengthwise according to the specifications of the designed battery. At this time, the blade can be changed depending on the size of the battery cell to be manufactured.

[0044] The assembly process (S20) is the process of assembling the positive electrode plate and negative electrode plate manufactured through the electrode process together with a separator to create a finished cell. The manufacturing procedure differs depending on the battery type (cylindrical, pouch type, or prismatic), and the technologies applied also differ from manufacturer to manufacturer.

[0045] Furthermore, the activation / inspection process (S30) is a process to activate electrical energy and confirm its stability. The activation process is carried out by repeatedly performing aging and charging / discharging. In the "aging" process, the battery is stored at room temperature while maintaining a constant temperature and humidity so that the electrolyte permeates the positive and negative electrodes. Once the electrolyte is dispersed inside the battery and the movement of ions between the positive and negative electrodes becomes smooth, the battery is partially charged to activate the cells. At this time, all lithium ions move to the negative electrode, and as the electrolyte decomposes, a thin solid film called "SEI," which is ion-conductive, is formed on the surface of the negative electrode.

[0046] After the activation process, the batteries undergo a test to check their charging capacity and sort out any defective batteries before being shipped.

[0047] The image brightness correction method according to an embodiment of the present invention can be applied to the electrode process, particularly the slitting process, in the manufacturing process of a battery.

[0048] Figure 2 is a conceptual diagram of a slitting process to which embodiments of the present invention can be applied.

[0049] The slitting process can be performed, for example, on a jumbo roll, which is a roll of thinly stretched electrodes discharged through a roll press process. The jumbo roll has electrode sheets coated and dried with electrode active material wound on it. In this case, it is preferable that the electrode sheets coated and dried with electrode active material be understood as coated electrode sheets after the coating process is completed.

[0050] The electrode (positive electrode plate or negative electrode plate) to be inspected during the battery slitting process according to the embodiment of the present invention comprises an active material coated portion in which an active material slurry is coated on an aluminum or copper thin film, an uncoated plain portion, and an insulating portion to which an insulating material is attached or coated.

[0051] For the slitting process, the electrode sheet, which is wound in a roll, is unwound by rotation. Referring to Figure 2, the jumbo roll 100 is unwound by the rotation of the unwinding roller U, and the unwound electrodes are cut by slitting devices mounted on separate slitting lanes during the conveying process to form multiple unit electrode sheets. Each of the multiple unit electrode sheets is wound up by a rewinder. The rewinder may include a cylindrical winding core C for winding up the unit electrode sheets.

[0052] As shown in Figure 2, as the slitting process progresses, a unit electrode roll P (also known as a pancake) can be generated for each slitting lane. On the other hand, the slitting process may include not only a first slitting process that cuts a jumbo roll into multiple unit electrode sheets, but also a second slitting process that further cuts one unit electrode sheet to form multiple sub-unit electrode sheets, in which case a sub-unit electrode roll can be formed as a result of the slitting process.

[0053] Figures 3a and 3b show examples of inspection areas of an electrode inspection device according to an embodiment of the present invention.

[0054] The electrode to be inspected in the electrode inspection device according to the embodiment of the present invention may be a positive electrode or a negative electrode. Figure 3a shows an example of a positive electrode for a stacked electrode assembly, and Figure 3b shows an example of a positive electrode for a jelly roll type electrode assembly.

[0055] Referring to Figure 3a, the positive electrode 100 includes a positive electrode current collector 110 and a positive electrode tab 120 protruding from the positive electrode current collector 110. On the positive electrode current collector 110, an insulating coating portion 130 is formed at the boundary between the positive electrode mixture coated portion (or coating portion) 111, to which the positive electrode mixture 140 is applied, and the positive electrode blank portion 112, to which the positive electrode mixture 140 is not applied. The positive electrode tab 120, to which the positive electrode mixture is not applied, can also be considered part of the positive electrode blank portion. In the example in Figure 3a, the insulating portion 130 is formed over the entire positive electrode blank portion 112, but the insulating portion can also be formed only on a part of the positive electrode blank portion of the positive electrode current collector.

[0056] Furthermore, the positive electrode 200 shown in Figure 3b is a positive electrode for a jelly roll type electrode assembly. An insulating portion 230 is formed at the boundary between the positive electrode coated portion 211, on which the positive electrode mixture 240 is applied to the current collector (aluminum foil), and the plain portion 212, on which the positive electrode mixture 240 is not applied. A positive electrode tab 220 is attached to the end of the plain portion 212 in a form that protrudes upward.

[0057] In Figures 3a and 3b, the insulating parts 130;230 can improve the safety of the secondary battery by preventing short circuits caused by contact between the positive and negative electrodes.

[0058] The inspection area according to the embodiment of the present invention may include one or more areas contained within an electrode placed during the electrode process of a battery manufacturing process. More specifically, the inspection area according to the embodiment of the present invention may include one or more areas of the coated portion, plain portion, and insulating portion of the electrode, which are distinguished by the attributes of the area. When images of the coated portion, plain portion, and insulating portion of the electrode are analyzed, the brightness of each area image is shown to differ depending on the attributes of the area.

[0059] Figure 4 is a schematic flowchart of an image brightness correction method according to an embodiment of the present invention.

[0060] The image brightness correction method according to an embodiment of the present invention can be performed by an electrode inspection apparatus according to an embodiment of the present invention. The electrode inspection apparatus includes or can be linked to an imaging apparatus (image capture device), i.e., an optical system, and an image of the object to be inspected can be acquired by the image capture device.

[0061] Referring to Figure 4, the electrode inspection device can acquire multiple images of the appearance of the object to be inspected, captured at different brightness levels from the imaging device, i.e., the camera (S310). According to an embodiment of the present invention, the object to be inspected may be an electrode (positive electrode or negative electrode) in the electrode process of the battery manufacturing process.

[0062] Here, the multiple images captured at different brightness levels may include a first image captured at a first brightness level and a second image captured at a second brightness level. The reason for capturing the same target object at different brightness levels is that the appropriate brightness level for identification and analysis differs depending on the characteristics of the multiple inspection areas contained within the target object. Therefore, the detection factors to be analyzed and detected through the first image may be different from the detection factors to be analyzed and detected through the second image.

[0063] For example, if the first image is relatively bright and the second image is relatively dark, the coated area and the plain area can be extracted as the inspection area in the first image. In the second image, the insulating area and the plain area can be extracted as the inspection area.

[0064] The electrode inspection device extracts one or more inspection target regions from the acquired image (S320). Here, the inspection target region (ROI: Region of Interest) indicates the area in the inspection image that is actually inspected. According to embodiments of the present invention, the inspection target region may include one or more areas of the coated portion, plain portion, and insulating portion of the electrode.

[0065] The electrode inspection device further calculates the brightness of each of the extracted inspection target areas (S330). More specifically, it calculates the brightness of the coated area, the plain area, and the insulating area within the electrode. Here, the brightness of each inspection area can be calculated by converting the image to grayscale, calculating the brightness values ​​of all pixels included in the inspection area, and averaging the results.

[0066] The electrode inspection device verifies whether the brightness of one or more inspection target areas calculated is within the brightness threshold range set for each inspection target area (S340). The brightness threshold range set for each inspection target area can be defined by an upper limit and a lower limit. The brightness threshold range will be explained in detail in Figures 5 and 6 below.

[0067] The electrode inspection device calculates a brightness correction value by reflecting the target brightness in the brightness of the inspection area according to the comparison result with the brightness threshold (S350). In other words, if the average brightness of the inspection area is outside the range of the lower brightness limit or the upper brightness limit, the electrode inspection device can calculate a brightness correction value based on the difference between the average brightness of the inspection area and the target brightness.

[0068] The calculated brightness correction value is transmitted to the imaging device (S360) and can be used for the next imaging of the object to be inspected.

[0069] Figure 5 is a table showing the inspection items in each image according to the embodiment of the present invention.

[0070] In an embodiment of the present invention, the first image is an image having a first brightness, and the second image is an image having a second brightness. The second brightness is different from the first brightness and can be lower than the first brightness. That is, the first image and the second image are images of the same object, but are images taken at different brightness levels.

[0071] In the table in Figure 5, the first image may be a relatively bright image, and the second image may be a relatively dark image.

[0072] In the embodiment of the present invention, the first image allows for the extraction of the coated portion and the plain portion as the inspection target area. Furthermore, the second image allows for the extraction of the insulating portion and the plain portion as the inspection target area.

[0073] In each image, the lower limit of brightness (LCL) and the upper limit of brightness (UCL) for the area to be inspected are defined. Specifically, in the first image, the lower limit of brightness (LCL) for the coated area is defined as 90 and the upper limit of brightness (UCL) as 110, while the lower limit of brightness (LCL) for the plain area is defined as 250 and the upper limit of brightness (UCL) as 255. In the first image, the target brightness (Target) for the coated area is set to 100 and the target brightness (Target) for the plain area is set to 255.

[0074] On the other hand, in the second image, the lower limit of brightness (LCL) for the insulated area is defined as 40 and the upper limit of brightness (UCL) as 60, while the lower limit of brightness (LCL) for the plain area is defined as 130 and the upper limit of brightness (UCL) as 230. In the second image, the target brightness (Target) for the insulated area is set to 50 and the target brightness (Target) for the plain area is set to 180.

[0075] The upper limit (UCL), lower limit (LCL), and target brightness (Target) for the same plain area are set differently in the first and second images because the overall brightness of the first image and the overall brightness of the second image are set differently.

[0076] Figure 6 is a table showing the items to be detected through each image inspection according to the embodiment of the present invention.

[0077] Referring to Figure 6, in the embodiment of the present invention, the items to be detected through the first image may include the secondary slit edge for measuring the secondary slit width, and surface defects in the coated and uncoated portions. Furthermore, the items to be detected through the second image may include the primary slit edge for measuring the primary slit width, the boundary between the coated and uncoated portions, the insulating portion edge, and surface defects in the insulating portion.

[0078] Here, the electrode slitting process can consist of a primary slit and a secondary slit. On the other hand, the primary slitting process can be understood as a process of cutting a jumbo roll into multiple unit electrode sheets (for example, four unit electrode sheets), and the secondary slitting process can be understood as a process of further cutting one unit electrode sheet to form multiple sub-unit electrode sheets.

[0079] Figure 7 is a diagram showing the items to be detected through each image inspection according to the embodiment of the present invention, displayed on the image.

[0080] In Figure 7, the first image 71 and the second image 72 are images obtained by imaging the same target object at different brightness levels. The first image 71 is brighter than the second image 72 and is suitable for detecting surface defects in the coated area and the plain area. On the other hand, the second image 72 is darker and is suitable for detecting the boundary between the coated area and the plain area, the edge of the insulating area, and surface defects in the insulating area.

[0081] Figure 8 shows an example of a brightness correction method for images with relatively low brightness according to an embodiment of the present invention.

[0082] The correction method in Figure 8 shows the operation procedure of a brightness correction method applied to a relatively bright image among multiple images acquired at different brightness levels for the same target object. It can be understood as a flowchart that shows some steps of the overall method in Figure 4 in more detail for a specific image. In other words, some steps of the method shown in Figure 8 can partially overlap with the steps of the brightness correction method shown in Figure 4.

[0083] The image brightness correction method according to an embodiment of the present invention can be performed by an electrode inspection apparatus according to an embodiment of the present invention. The electrode inspection apparatus includes or can be linked to an imaging apparatus (imaging device), i.e., an optical system, and the image of the object to be inspected can be acquired by the imaging device.

[0084] As described above, according to the embodiment of the present invention, the inspection target area for a relatively bright image is the coated area and the plain area.

[0085] In other words, the electrode inspection device extracts the coated and plain areas, which are the inspection areas, from the acquired image and calculates the brightness value of each area (S331). The brightness value of the plain area is compared with the upper limit (UCL) and lower limit (LCL) of brightness for the plain area, and the brightness value of the coated area is compared with the upper limit (UCL) and lower limit (LCL) of brightness for the coated area (S341). If the brightness value of each area is within the specified range (set appropriate range) (yes in S341), the brightness value control procedure is unnecessary and the procedure is terminated.

[0086] In contrast, if either the brightness value of the plain area or the brightness value of the coated area is outside the specified range, it is determined whether the brightness value of the plain area is outside the specified range (S342) or whether the brightness value of the coated area is outside the specified range (S343).

[0087] If the brightness value of the plain area is outside the specified range (No in S342), the brightness correction value for the plain area is set according to the difference between the current brightness value of the plain area and the target brightness value of the plain area (S351). More specifically, (target brightness value of the plain area - current brightness value of the plain area) is set as the brightness correction value for the plain area. Here, if the current brightness value of the plain area exceeds the upper limit of the plain area, the brightness correction value becomes a negative value, and conversely, if the current brightness value of the plain area is less than the lower limit of the plain area, the brightness correction value becomes a positive value. On the other hand, if the brightness value of the plain area is within the specified range (Yes in S342), the brightness correction value for the plain area is set to "0" (S352).

[0088] Next, if the brightness value of the coated area is not within the specified range (No in S343), the brightness correction value for the coated area is set according to the difference between the current brightness value of the coated area and the target brightness value of the coated area (S353). More specifically, (target brightness value of the coated area - current brightness value of the coated area) is set as the brightness correction value. However, if the current brightness value of the coated area exceeds the upper limit of the coated area, the brightness correction value becomes a negative value, and conversely, if the current brightness value of the coated area is less than the lower limit of the coated area, the brightness correction value becomes a positive value. On the other hand, if the brightness value of the coated area is within the specified range (Yes in S343), the brightness correction value for the coated area is set to "0" (S354).

[0089] Subsequently, the camera exposure time correction value is calculated according to the brightness correction value of the plain area and the brightness correction value of the coated area (S360). More specifically, the camera exposure time correction value is calculated by multiplying the larger of the brightness correction value of the plain area and the brightness correction value of the coated area by a control constant. Here, the control constant is a constant used to compensate for the difference in expression units between the brightness correction value and the exposure time correction value. On the other hand, if the correction value is negative, a larger value is selected based on the absolute value of that value, and the camera exposure time correction value is calculated by multiplying it by the control constant.

[0090] The calculated camera exposure time adjustment value is provided to the camera, which can then apply this value to the next image of the target object to adjust the brightness of the captured image. Here, the total amount of light received by the camera sensor can be expressed as the product of the exposure time and the area receiving the light. Therefore, increasing the camera exposure time can also increase the brightness of the image.

[0091] On the other hand, the steps (S331 to S360) of the image brightness correction method shown in Figure 8 above can be repeated until the image brightness of each target area is within an appropriate range, i.e., satisfies the specified specification range.

[0092] Figure 9 is a block diagram of an electrode inspection apparatus according to an embodiment of the present invention.

[0093] An electrode inspection apparatus 900 according to an embodiment of the present invention is an apparatus for inspecting electrodes in the electrode process of a battery manufacturing process, and may include at least one processor 910, a memory 920 for storing at least one instruction executed through the processor, and a transceiver 930 connected to a network for communication.

[0094] The electrode inspection apparatus according to an embodiment of the present invention may be linked to or include an imaging device for capturing images of the appearance of a target object.

[0095] Here, at least one of the above commands may include: a command to receive multiple images from an imaging device, each capturing the appearance of a target object at different brightness levels; a command to extract one or more inspection target areas from the above images; a command to compare the brightness of the one or more inspection target areas with a brightness threshold set for each inspection target area; and a command to calculate a brightness correction value by reflecting the target brightness in the brightness of the inspection target areas according to the comparison result.

[0096] The brightness of the inspection area can be set to the average brightness of the pixels within that area.

[0097] A command that compares the brightness of one or more inspection areas with a brightness threshold set for each inspection area may include a command that compares the average brightness of an inspection area with a brightness lower limit and brightness upper limit set for that inspection area.

[0098] The command to calculate a brightness correction value by reflecting the target brightness in the brightness of the inspection area, in accordance with the above comparison results, may include a command to calculate the brightness correction value based on the difference between the average brightness and the target brightness if the average brightness of the inspection area is outside the range of the above lower brightness limit or upper brightness limit.

[0099] The command to calculate the brightness correction value based on the difference between the average brightness and the target brightness may include a command to calculate a camera exposure time adjustment value, which is calculated by multiplying the difference between the average brightness and the target brightness by a control constant.

[0100] The command to calculate the brightness correction value based on the difference between the average brightness and the target brightness may include a command to calculate the camera exposure time adjustment value by multiplying the largest of the multiple brightness correction values ​​by a control constant if there are multiple inspection target areas in a single image and the brightness correction values ​​calculated for the multiple inspection target areas are different from each other.

[0101] The above at least one instruction may further include an instruction to provide the calculated camera exposure time adjustment value to the imaging device.

[0102] The above-mentioned multiple inspection areas may include one or more areas of the electrode, such as the coated portion, the plain portion, and the insulating portion, which are distinguished by the attributes of the respective areas.

[0103] Multiple images captured at different brightness levels may include a first image captured at a first brightness level and a second image captured at a second brightness level, the second brightness level being different from the first brightness level.

[0104] On the other hand, at least one of the above instructions may further include an instruction to perform a defect inspection of the target object in the process using the brightness-corrected inspection area.

[0105] The electrode inspection device 900 may further include an input interface device 940, an output interface device 950, a storage device 960, and the like. Each component included in the electrode inspection device 900 can communicate with one another via a bus 970.

[0106] The storage device 960 can store a number of images captured by the imaging device, and at least one image produced in each step of the inspection method according to an embodiment of the present invention. The images stored in the storage device 960 can be provided to at least one processor 910 as needed during the execution of the method according to an embodiment of the present invention.

[0107] Here, processor 910 can mean a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which the method according to the embodiment of the present invention is performed. Memory (or storage device) can consist of at least one of volatile storage media and non-volatile storage media. For example, memory can consist of at least one of read-only memory (ROM) and random access memory (RAM).

[0108] The operation of the method according to an embodiment of the present invention can be embodied as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes all types of recording devices that store data that can be read by a computer system. Furthermore, computer-readable recording media can be distributed across networked computer systems, allowing computer-readable programs or code to be stored and executed in a distributed manner.

[0109] Some aspects of the present invention have been described in the context of apparatus, but they can also be described by corresponding methods, where a block or apparatus corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method can be described by corresponding blocks or items or features of corresponding apparatus. Some or all of the method steps can be carried out by (or using) hardware devices such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most important method steps can be carried out by such devices.

[0110] While preferred embodiments of the present invention have been described above with reference to those skilled in the art, a person skilled in the art will understand that the present invention can be modified and altered in various ways without departing from the spirit and scope of the invention as set forth in the following claims. [Explanation of Symbols]

[0111] 100 positive electrode 110 Positive electrode current collector 111 Positive electrode mixture coating area 112 Positive electrode blank area 120 Positive Tab 130 Insulation part 140 Cathode mixture 200 positive electrode 200 Jumbo Rolls 211 Positive electrode coating section 212 Plain section 220 Positive Tab 230 Insulation part 240 Cathode mixture 900 Electrode Inspection Device 910 Processor 920 memory 930 Transceiver 940 Input Interface Device 950 Output Interface Device 960 Storage device 970 Bus

Claims

1. A step of obtaining multiple images of the target object, each captured at a different brightness level; Steps include extracting one or more areas to be examined from each image; A step of comparing the brightness of one or more inspection target areas with a brightness threshold set for each inspection target area; and An image brightness correction method, comprising the step of calculating a brightness correction value by reflecting the target brightness in the brightness of the area to be inspected according to the comparison result.

2. The image brightness correction method according to claim 1, wherein the brightness of the inspection target area is set to the average brightness of the pixels within the inspection target area.

3. The step of comparing the brightness of one or more inspection target areas with a brightness threshold set for each inspection target area is: The image brightness correction method according to claim 1 or 2, comprising the step of comparing the average brightness of the area to be inspected with a brightness lower limit and a brightness upper limit set for the area to be inspected.

4. The step of calculating a brightness correction value by reflecting the target brightness in the brightness of the inspection area according to the comparison results is as follows: The image brightness correction method according to claim 3, further comprising the step of calculating the brightness correction value based on the difference between the average brightness and the target brightness if the average brightness of the area to be inspected is outside the range of the lower brightness limit to the upper brightness limit.

5. The step of calculating the brightness correction value based on the difference between the average brightness and the target brightness is: The image brightness correction method according to claim 4, further comprising the step of calculating a camera exposure time adjustment value obtained by multiplying the difference between the average brightness and the target brightness by a control constant.

6. The step of calculating the brightness correction value based on the difference between the average brightness and the target brightness is: If an image contains multiple inspection target areas, and the brightness correction values ​​calculated for these multiple inspection target areas are different from each other, The image brightness correction method according to claim 4, further comprising the step of calculating a camera exposure time adjustment value by multiplying the largest value among a plurality of brightness correction values ​​by a control constant.

7. The image brightness correction method according to claim 6, further comprising the step of providing the calculated camera exposure time adjustment value to the imaging device.

8. The image brightness correction method according to claim 1 or 2, wherein the target object includes an electrode in the electrode process of the battery manufacturing process.

9. The one or more areas to be inspected are: The image brightness correction method according to claim 1, comprising one or more regions of the electrode, which are divided according to the attributes of the region, including a coated portion, a plain portion, and an insulating portion.

10. The aforementioned multiple images, each captured at a different brightness, This includes a first image captured at a first brightness level and a second image captured at a second brightness level. The image brightness correction method according to claim 1 or 2, characterized in that the second brightness is different from the first brightness.

11. The image brightness correction method according to claim 1 or 2, wherein a defect inspection of the target object during the process is performed using the brightness-corrected inspection target area.

12. A device for inspecting electrodes during the electrode process in the battery manufacturing process, At least one processor; and Includes memory for storing at least one instruction executed through the at least one processor, The aforementioned at least one instruction, A command to receive multiple images from an imaging device, each capturing the appearance of a target object at a different brightness level; A command to extract one or more target regions within each image; A command to compare the brightness of one or more inspection target areas with a brightness threshold set for each inspection target area; and An electrode inspection device that includes a command to calculate a brightness correction value by reflecting the target brightness in the brightness of the area to be inspected, according to the comparison result.

13. The electrode inspection apparatus according to claim 12, wherein the brightness of the inspection target area is set to the average brightness of the pixels within the inspection target area.

14. The command to compare the brightness of one or more inspection target areas with a brightness threshold set for each inspection target area is: The electrode inspection apparatus according to claim 12 or 13, which includes a command to compare the average brightness of the area to be inspected with a lower brightness limit and a upper brightness limit set for the area to be inspected.

15. The command to calculate a brightness correction value by reflecting the target brightness in the brightness of the area to be inspected, in accordance with the comparison results, The electrode inspection apparatus according to claim 14, further comprising a command to calculate the brightness correction value based on the difference between the average brightness and the target brightness when the average brightness of the area to be inspected is outside the range of the lower brightness limit or the upper brightness limit.

16. The command to calculate the brightness correction value based on the difference between the average brightness and the target brightness is: The electrode inspection apparatus according to claim 15, which includes an instruction to calculate a camera exposure time adjustment value calculated by multiplying the difference between the average brightness and the target brightness by a control constant.

17. The command to calculate the brightness correction value based on the difference between the average brightness and the target brightness is: If an image contains multiple inspection target areas, and the brightness correction values ​​calculated for these multiple inspection target areas are different from each other, The electrode inspection apparatus according to claim 15, which includes an instruction to calculate a camera exposure time adjustment value by multiplying the largest value among a plurality of brightness correction values ​​by a control constant.

18. The aforementioned at least one instruction, The electrode inspection apparatus according to claim 17, further comprising an instruction to provide the imaging device with a calculated camera exposure time adjustment value.

19. The one or more areas to be inspected are: The electrode inspection apparatus according to claim 12 or 13, comprising one or more regions of the electrode, which are divided according to the attributes of the region, including a coated portion, a plain portion, and an insulating portion.

20. Multiple images taken at different brightness levels are This includes a first image captured at a first brightness level and a second image captured at a second brightness level. The electrode inspection apparatus according to claim 12 or 13, characterized in that the second brightness is different from the first brightness.

21. The aforementioned at least one instruction, The electrode inspection apparatus according to claim 12 or 13, further comprising an instruction to perform a defect inspection of a target object during the process using the brightness-corrected inspection target area.

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