Image brightness correction method and electrode inspection apparatus using same

Abstract

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

Description

Image brightness correction method and electrode inspection device using the same

[0001] This application claims the benefit of Korean Patent Application No. 10-2023-0181389 filed with the Korean Intellectual Property Office on December 14, 2023, the entire disclosure of which is incorporated herein by reference.

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

[0003] Secondary batteries are rechargeable batteries that can be reused after discharge. They can be used as energy sources for small devices such as mobile phones, tablet PCs, and vacuum cleaners, and are also utilized as medium- to large-scale energy sources for personal mobility, automobiles, and energy storage systems (ESS) for smart grids. Depending on the system requirements, secondary batteries are used in the form of assemblies such as battery modules, in which multiple battery cells are connected in series and parallel, or battery packs, in which battery modules are connected in series and parallel.

[0004] Batteries can be manufactured through a series of processes, including electrode manufacturing, assembly, and activation / inspection. The resulting battery cells or the output of each process are inspected for defects using inspection equipment. A commonly used defect inspection method is image-based inspection. Image inspection utilizes an optical system to capture images of components and semi-finished products during the manufacturing process and then uses a detection algorithm to detect defects.

[0005] In this regard, during the electrode slitting process, slitting width and the presence of electrode surface defects are among the key factors affecting product quality, and quality inspection using images can be performed. In this case, image brightness can be directly related to inspection quality.

[0006] However, due to changes in raw materials or process conditions, the brightness of the electrode inspection image can fluctuate to a degree that makes normal inspection impossible. In such cases, all related manufacturing equipment must be shut down, and workers must adjust the lighting intensity or camera exposure to bring the inspection image brightness within the acceptable inspection range. Consequently, equipment downtime can lead to decreased production rates and increased production costs, as well as over-inspection and defects caused by manual labor.

[0007] An object of the present invention to solve the above problems is to provide an image brightness correction method for adjusting the brightness of an electrode image during a battery electrode process.

[0008] Another object of the present invention to solve the above problems is to provide a device for inspecting an electrode using the image brightness correction method.

[0009] According to one embodiment of the present invention, a method for correcting image brightness for achieving the above object may include: acquiring a plurality of images in which the appearance of a target object is captured at different brightnesses; 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 area based on the comparison result.

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

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

[0012] The step of calculating a brightness correction value by reflecting the target brightness in the brightness of the inspection target area based on the comparison result may include a step of calculating the brightness correction value based on a difference value between the average brightness and the target brightness when the average brightness of the inspection target area is outside the range of the brightness lower limit value and the brightness upper limit value.

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

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

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

[0016] The above target object may include an electrode during an electrode process of a battery manufacturing process.

[0017] The one or more inspection target areas may include one or more areas of the coated area, the uncoated area, and the insulating area of ​​the electrode, which are distinguished according to the properties of the area.

[0018] A plurality of images captured at different brightnesses include a first image captured at a first brightness and a second image captured at a second brightness, wherein the second brightness is different from the first brightness.

[0019] Defect inspection of a target object being processed can be performed using the above brightness-corrected inspection target area.

[0020]

[0021] According to one embodiment of the present invention for achieving the above other objects, a device for inspecting an electrode of a product is a device for inspecting an electrode during an electrode process of a battery manufacturing process, and may include at least one processor; and a memory for storing at least one command executed through the at least one processor, wherein the at least one command may include a command for receiving a plurality of images of the appearance of a target object captured at different brightnesses from an imaging device; a command for extracting at least one inspection target region within each image; a command for comparing the brightness of the at least one inspection target region with a brightness threshold set for each inspection target region; and a command for calculating a brightness correction value by reflecting a target brightness to the brightness of the inspection target region based on the comparison result.

[0022] The brightness of the above inspection target area can be set to the average brightness of pixels within the inspection target area.

[0023] The command to compare the brightness of one or more of the inspection target areas with a brightness threshold set for each inspection target area may include a command to compare the average brightness of the inspection target area with a brightness lower limit and brightness upper limit set for the inspection target area.

[0024] The command to calculate a brightness correction value by reflecting the target brightness in the brightness of the inspection target area according to the comparison result may include a command to calculate the brightness correction value based on a difference value between the average brightness and the target brightness when the average brightness of the inspection target area is outside the range of the brightness lower limit value and the brightness upper limit value.

[0025] The command to calculate the brightness compensation value based on the difference value between the average brightness and the target brightness may include a command 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.

[0026] The command to calculate the brightness compensation value based on the difference value between the average brightness and the target brightness may include a command to calculate a camera exposure time adjustment value by multiplying the largest value among the plurality of brightness compensation values ​​by a control constant when there are multiple inspection target areas included in one image and the brightness compensation values ​​calculated for the multiple inspection target areas are different from each other.

[0027] The at least one command may further include a command to provide the generated camera exposure time adjustment value to the imaging device.

[0028] The one or more inspection target areas may include one or more areas of the coated area, the uncoated area, and the insulating area of ​​the electrode, which are distinguished according to the properties of the area.

[0029] The plurality of images captured at different brightnesses may include a first image captured at a first brightness and a second image captured at a second brightness, wherein the second brightness may be different from the first brightness.

[0030] Meanwhile, the at least one command may further include a command to perform a defect inspection of a target object being processed using the brightness-corrected inspection target area.

[0031] According to the above-described embodiment of the present invention, in battery electrode image inspection, quantification and automation of image quality management can be achieved by automatically correcting the brightness of the inspection image in real time.

[0032] Additionally, electrode inspection can be performed without stopping the manufacturing facility, preventing damage caused by facility downtime.

[0033] In addition, it can eliminate the risk of over-inspection and under-inspection due to human error in existing manual work.

[0034] Figure 1 is a schematic diagram of a battery manufacturing process to which the present invention can be applied.

[0035] Figure 2 is a conceptual diagram of a slitting process to which the present invention can be applied.

[0036] Figures 3a and 3b illustrate examples of inspection target areas of an electrode inspection device according to an embodiment of the present invention.

[0037] Figure 4 is a schematic flowchart of an image brightness correction method according to an embodiment of the present invention.

[0038] Figure 5 is a table showing inspection items in each image according to an embodiment of the present invention.

[0039] Figure 6 is a table showing items to be detected through each image inspection according to an embodiment of the present invention.

[0040] FIG. 7 is a drawing showing an item to be detected through each image inspection according to an embodiment of the present invention displayed on an actual image.

[0041] FIG. 8 illustrates an example of a brightness correction method for an image having low brightness according to an embodiment of the present invention.

[0042] Figure 9 is a block diagram of an electrode inspection device according to an embodiment of the present invention.

[0043] The present invention is susceptible to various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention. Throughout the description of each drawing, similar reference numerals have been used to designate similar components.

[0044] Terms such as "first," "second," "A," and "B" may be used to describe various components, but these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, the first component could be referred to as the "second component," and similarly, the second component could also be referred to as the "first component." The term "and / or" includes any combination of multiple related items listed or any one of multiple related items listed.

[0045] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0046] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0047] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and shall not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0048]

[0049] Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0050]

[0051] Figure 1 is a schematic diagram of a battery manufacturing process to which the present invention can be applied.

[0052] Batteries can be manufactured through an electrode process (S10), an assembly process (S20), and an activation / inspection process (S30). The completed battery, which undergoes these processes, is shipped in the form of a battery pack (or battery module) comprising multiple battery cells connected in series. The battery pack is connected to a load through its positive and negative terminals and can perform charge / discharge operations. Depending on the requirements of the system in which the battery is used, the battery pack can be configured to be connected in series or parallel.

[0053] More specifically, the electrode process (S10) may proceed in the following order: a 'mixing process' for mixing raw materials, a 'coating process' for applying the mixed slurry to a foil and drying it, a 'roll pressing process' for compressing the electrode to reduce the thickness of the electrode, a 'slitting process' for cutting the electrode to a preset width, and a 'notching process' for creating a tab on the electrode.

[0054] Here, the slitting process involves cutting the electrodes, which are produced through a thin roll pressing process, to fit the battery size. This process involves using a slitter to cut the electrodes vertically according to the designed battery specifications. The blade used may vary depending on the desired battery cell size.

[0055] The assembly process (S20) is the process of assembling the positive and negative plates manufactured through the electrode process together with the separator to create a finished cell. The manufacturing order differs depending on the battery type (cylindrical, pouch, square), and the technology applied also differs depending on the manufacturer.

[0056] In addition, the activation / inspection process (S30) is a process to activate electric energy and verify stability. The activation process is performed by repeating aging and charging / discharging. In the 'aging' process, the battery is stored at room temperature with a constant temperature and humidity so that the electrolyte permeates the positive and negative electrodes. When 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 cell. At this time, lithium ions completely move to the negative electrode and the electrolyte decomposes, forming an 'SEI' layer, an ion-conductive thin solid film, on the surface of the negative electrode.

[0057] Afterwards, the batteries that have gone through the activation process are tested for charging capacity and go through a process of sorting out defective batteries before being shipped.

[0058] The image brightness correction method according to the present invention can be applied to an electrode process, particularly a slitting process, during a battery manufacturing process.

[0059]

[0060] Figure 2 is a conceptual diagram of a slitting process to which the present invention can be applied.

[0061] The slitting process can be performed on a jumbo roll, which is a rolled-up form of a thinly spread electrode, for example, produced through a roll pressing process. The jumbo roll is wound with an electrode sheet coated and dried with an electrode active material. At this time, it is preferable to understand the electrode sheet coated and dried with an electrode active material as a coated electrode sheet after completing the coating process.

[0062] The electrode (positive electrode or negative electrode) to be inspected during the battery slitting process according to the present invention is configured to include an active material-coated portion in which an active material slurry is coated on an aluminum or copper thin film, an uncoated portion, and an insulating portion in which an insulating material is attached or coated.

[0063] For the slitting process, an electrode sheet wound in a roll shape is unwound by rotation. Referring to FIG. 2, a jumbo roll (200) is unwound by the rotation of an unwinder roller (U), and the unwound electrode is cut by a slitting device installed in each slitting lane during a returning process to form a plurality of unit electrode sheets. Each of the plurality of unit electrode sheets is wound by a rewinder. The rewinder may include a cylindrical winding core (C) for winding the unit electrode sheets.

[0064] As illustrated in Fig. 2, as the slitting process progresses, a unit electrode roll (P; also known as a pancake) may be created for each slitting lane. Meanwhile, the slitting process may include not only a first slitting process for cutting a jumbo roll into a plurality of unit electrode sheets, but also a second slitting process for additionally cutting one unit electrode sheet to form a plurality of sub-unit electrode sheets. In this case, a sub-unit electrode roll may be formed as a result of the slitting process.

[0065]

[0066] Figures 3a and 3b illustrate examples of inspection target areas of an electrode inspection device according to an embodiment of the present invention.

[0067] The electrode to be inspected by the electrode inspection device according to an embodiment of the present invention may be an anode or a cathode. FIG. 3a illustrates an example of an anode for a laminated electrode assembly, and FIG. 3b illustrates an example of an anode for a jelly-roll type electrode assembly.

[0068] Referring to FIG. 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). An insulating coating portion (130) is formed on the positive electrode current collector (110) at the boundary between a positive electrode mixture application portion (or coating portion) (111) on which a positive electrode mixture (140) is applied and a positive electrode non-coated portion (112) on which the positive electrode mixture (140) is not applied. The positive electrode tab (120) on which the positive electrode mixture is not applied can also be viewed as a part of the positive electrode non-coated portion. In the example of FIG. 3A, the insulating portion (130) is formed on the entire positive electrode non-coated portion (112), but the insulating portion may be formed on only a part of the positive electrode non-coated portion of the positive electrode current collector.

[0069] Additionally, the positive electrode (200) illustrated in Fig. 3b is an positive electrode for a jelly-roll type electrode assembly. An insulating portion (230) is formed at the boundary between a positive electrode coating portion (211) on which a positive electrode mixture (240) is applied on a current collector (aluminum foil) and a non-coated portion (212) on which a positive electrode mixture (240) is not applied, and a positive electrode tab (220) is attached in an upwardly protruding form to an end of the non-coated portion (212).

[0070] In FIGS. 3a and 3b, the insulating portion (130; 230) can improve the safety of the secondary battery by preventing a short circuit caused by contact between the positive and negative electrodes.

[0071] The inspection target region according to an embodiment of the present invention may include one or more regions within an electrode placed during an electrode process in a battery manufacturing process. More specifically, the inspection target region according to an embodiment of the present invention may include one or more regions among a coated region, a non-coated region, and an insulating region of the electrode, which are distinguished according to the properties of the corresponding regions. When analyzing the images of the coated region, non-coated region, and insulating region of the electrode, the brightness of the images of each region appears differently due to the properties of the corresponding regions.

[0072]

[0073] Figure 4 is a schematic flowchart of an image brightness correction method according to an embodiment of the present invention.

[0074] The image brightness correction method according to an embodiment of the present invention can be performed by an electrode inspection device according to the present invention. The electrode inspection device may include or be linked to an imaging device (image pickup device), i.e., an optical system, and an image of the inspection target can be acquired by the image pickup device.

[0075] Referring to FIG. 4, the electrode inspection device can acquire multiple images of the exterior of an object to be inspected at different brightness levels from an imaging device, i.e., a camera (S310). According to an embodiment of the present invention, the object to be inspected may be an electrode (anode or cathode) during an electrode process in a battery manufacturing process.

[0076] 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 brightness levels suitable for identification and analysis vary depending on the characteristics of the multiple inspection target areas contained within the target object. Accordingly, the detection factors to be analyzed and detected through the first image may differ from the detection factors to be analyzed and detected through the second image.

[0077] For example, when the first image is a relatively bright image and the second image is a relatively dark image, the coated area and the uncoated area can be extracted as inspection target areas from the first image. Additionally, the insulated area and the uncoated area can be extracted as inspection target areas from the second image.

[0078] 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) represents the region in the inspection image where the actual inspection will be performed. According to an embodiment of the present invention, the inspection target region may include one or more of the coated portion, the uncoated portion, and the insulating portion of the electrode.

[0079] The electrode inspection device also calculates the brightness of each extracted inspection target area (S330). More specifically, it calculates the brightness of the coated area, the uncoated area, and the insulated 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 within the inspection area, and averaging them.

[0080] The electrode inspection device verifies whether the brightness of one or more generated inspection target areas falls 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 upper and lower limits. The brightness threshold range is described in detail with reference to Figures 5 and 6 below.

[0081] The electrode inspection device calculates a brightness correction value by reflecting the target brightness to the brightness of the inspection target area based on the comparison result with the brightness threshold (S350). That is, if the average brightness of the inspection target area falls outside the range of the lower brightness limit and 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 target area and the target brightness.

[0082] 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.

[0083]

[0084] Figure 5 is a table showing inspection items in each image according to an embodiment of the present invention.

[0085] According to 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 has a different brightness than the first brightness, and may have a lower brightness than the first brightness. In other words, the first image and the second image are images of the same object captured at different brightness levels.

[0086] In the table of Fig. 5a, the first image may be a relatively bright image, and the second image may be a relatively dark image.

[0087] In the first image according to the embodiment of the present invention, the coated portion and the uncoated portion can be extracted as the inspection target area. In addition, in the second image, the insulated portion and the uncoated portion can be extracted as the inspection target area.

[0088] In each image, the lower brightness limit (LCL) and upper brightness limit (UCL) for the inspection target area are defined. That is, in the first image, the lower brightness limit (LCL) of the coated area is defined as 90, the upper brightness limit (UCL) of the uncoated area is defined as 110, and the lower brightness limit (LCL) of the uncoated area is defined as 250, and the upper brightness limit (UCL) of the uncoated area is defined as 255. In the first image, the target brightness of the coated area is set to 100, and the target brightness of the uncoated area is set to 255.

[0089] Meanwhile, in the second image, the lower brightness limit (LCL) of the insulated part is defined as 40, the upper brightness limit (UCL) is defined as 60, the lower brightness limit (LCL) of the unlit part is defined as 130, and the upper brightness limit (UCL) is defined as 230. In the second image, the target brightness of the insulated part is set to 50, and the target brightness of the unlit part is set to 180.

[0090] For the same area, the upper brightness limit (UCL), lower brightness limit (LCL), and target brightness 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.

[0091]

[0092] Figure 6 is a table showing items to be detected through each image inspection according to an embodiment of the present invention.

[0093] Referring to FIG. 6, in an embodiment of the present invention, items to be detected through the first image may include a second slitting edge for measuring a second slitting width, surface defects of the coated portion and the uncoated portion. In addition, items to be detected through the second image may include a first slitting edge for measuring a first slitting width, a boundary between the coated portion and the uncoated portion, an edge of the insulated portion, and surface defects of the insulated portion.

[0094] Here, the slitting process of the electrode may be configured to include primary slitting and secondary slitting, while the primary slitting process may be understood as a process of cutting a jumbo roll into a plurality of unit electrode sheets (e.g., four unit electrode sheets), and the secondary slitting process may be understood as a process of further cutting one unit electrode sheet to form a plurality of sub-unit electrode sheets.

[0095]

[0096] FIG. 7 is a drawing showing an item to be detected through each image inspection according to an embodiment of the present invention displayed on an actual image.

[0097] In Fig. 7, the first image (71) and the second image (72) are images obtained by capturing the same target object at different brightness levels. The first image (71) is a brighter image than the second image (72) and is suitable for detecting surface defects in the coated portion and surface defects in the uncoated portion. On the other hand, the second image (72) is a darker image and is suitable for detecting the boundary between the coated portion and the uncoated portion, the edge of the insulated portion, and surface defects in the insulated portion.

[0098]

[0099] FIG. 8 illustrates an example of a brightness correction method for an image having relatively low brightness according to an embodiment of the present invention.

[0100] The correction method of Fig. 8 shows the operation sequence of a brightness correction method applied to a relatively bright image among multiple images acquired with different brightnesses for the same target object, and can be understood as a flowchart showing some steps of the entire method of Fig. 4 in more detail for a specific image. That is, some steps of the method illustrated in Fig. 8 may overlap with the steps of the brightness correction method illustrated in Fig. 4.

[0101] The image brightness correction method according to an embodiment of the present invention can be performed by an electrode inspection device according to the present invention. The electrode inspection device may include an imaging device (image pickup device), i.e., an optical system, or may be linked to an optical system, and an image of the inspection target can be acquired by the image pickup device.

[0102] Previously, according to the embodiment of the present invention, it was examined that the inspection target area for a relatively bright image is a coated area and an uncoated area.

[0103] That is, the electrode inspection device extracts the coated and uncoated areas, which are the inspection target areas, from the acquired image, and calculates the brightness value of each area (S331). The brightness value of the uncoated area is compared with the brightness upper limit (UCL) and brightness lower limit (LCL) of the uncoated area, and the brightness value of the coated area is compared with the brightness upper limit (UCL) and brightness lower limit (LCL) of the coated area (S341). If the brightness value of each area is within the specification range (set appropriate range) (example of S341), the brightness value control procedure is not necessary, and thus the procedure is terminated.

[0104] On the other hand, if either the brightness value of the uncoated portion or the brightness value of the coated portion is outside the specification range, it is determined whether the brightness value of the uncoated portion is outside the specification range (S342) or whether the brightness value of the coated portion is outside the specification range (S343).

[0105] If the brightness value of the unshaved area is not within the specification range (No in S342), the brightness compensation value of the unshaved area is set according to the difference between the current brightness value of the unshaved area and the target brightness value of the unshaved area (S351). More specifically, (target brightness value of the unshaved area - current brightness value of the unshaved area) is set as the brightness compensation value of the unshaved area. Here, if the current brightness value of the unshaved area exceeds the upper limit value of the unshaved area, the brightness compensation value becomes a negative value, and conversely, if the current brightness value of the unshaved area is less than the lower limit value of the unshaved area, the brightness compensation value becomes a positive value. On the other hand, if the brightness value of the unshaved area is within the specification range (Yes in S342), the brightness compensation value of the unshaved area is set to "0" (S352).

[0106] Next, if the brightness value of the coating part is not within the specification range (No in S343), the brightness correction value of the coating part is set according to the difference between the current brightness value of the coating part and the target brightness value of the coating part (S353). More specifically, (target brightness value of the coating part - current brightness value of the coating part) is set as the brightness correction value. If the current brightness value of the coating part exceeds the upper limit value of the coating part, the brightness correction value becomes a negative value, and conversely, if the current brightness value of the coating part is less than the lower limit value of the coating part, the brightness correction value becomes a positive value. On the other hand, if the brightness value of the coating part is within the specification range (Yes in S343), the brightness correction value of the coating part is set to "0" (S354).

[0107] Thereafter, the camera exposure time compensation value is calculated based on the brightness compensation value of the uncoated portion and the brightness compensation value of the coated portion (S360). More specifically, the camera exposure time compensation value is calculated by multiplying the larger value between the brightness compensation value of the uncoated portion and the brightness compensation value of the coated portion by a control constant. Here, the control constant is a constant for compensating for the difference in units of expression between the brightness compensation value and the exposure time compensation value. Meanwhile, if the compensation value is a negative value, a larger value is selected based on the absolute value of the corresponding value, and the camera exposure time compensation value is calculated by multiplying the larger value by the control constant.

[0108] The resulting camera exposure time adjustment value is then provided to the camera, which can then apply it to the next image of the target object to adjust the brightness of the captured image. The total amount of light captured by the camera sensor can be expressed as the product of the exposure time and the area receiving light. Therefore, increasing the camera exposure time can also increase the brightness of the image.

[0109] Meanwhile, the steps (S331 to S360) of the image brightness correction method of FIG. 8 described above can be repeatedly performed until the image brightness of each target area satisfies an appropriate range, i.e., a specified specification range.

[0110]

[0111] Figure 9 is a block diagram of an electrode inspection device according to an embodiment of the present invention.

[0112] An electrode inspection device (900) according to an embodiment of the present invention is a device for inspecting an electrode during an electrode process of a battery manufacturing process, and may include at least one processor (910), a memory (920) for storing at least one command executed through the processor, and a transmission / reception device (930) connected to a network for performing communication.

[0113] An electrode inspection device according to an embodiment of the present invention may be linked to or include an imaging device that captures the appearance of a target object.

[0114] Here, the at least one command may include a command to receive a plurality of images of the appearance of the target object captured at different brightnesses from the imaging device; a command to extract one or more inspection target areas within the 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 area based on the comparison result.

[0115] The brightness of the above inspection target area can be set to the average brightness of pixels within the inspection target area.

[0116] The command to compare the brightness of one or more of the inspection target areas with a brightness threshold set for each inspection target area may include a command to compare the average brightness of the inspection target area with a brightness lower limit and brightness upper limit set for the inspection target area.

[0117] The command to calculate a brightness correction value by reflecting the target brightness in the brightness of the inspection target area according to the comparison result may include a command to calculate the brightness correction value based on a difference value between the average brightness and the target brightness when the average brightness of the inspection target area is outside the range of the brightness lower limit value and the brightness upper limit value.

[0118] The command to calculate the brightness compensation value based on the difference value between the average brightness and the target brightness may include a command 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.

[0119] The command to calculate the brightness compensation value based on the difference value between the average brightness and the target brightness may include a command to calculate a camera exposure time adjustment value by multiplying the largest value among the plurality of brightness compensation values ​​by a control constant when there are multiple inspection target areas included in one image and the brightness compensation values ​​calculated for the multiple inspection target areas are different from each other.

[0120] The at least one command may further include a command to provide the generated camera exposure time adjustment value to the imaging device.

[0121] The above plurality of inspection target areas may include one or more areas of the coated area, the uncoated area, and the insulating area of ​​the electrode, which are distinguished according to the properties of the area.

[0122] The plurality of images captured at different brightnesses may include a first image captured at a first brightness and a second image captured at a second brightness, wherein the second brightness may be different from the first brightness.

[0123] Meanwhile, the at least one command may further include a command to perform a defect inspection of a target object being processed using the brightness-corrected inspection target area.

[0124] The electrode inspection device (900) may also include an input interface device (940), an output interface device (950), a storage device (960), etc. Each component included in the electrode inspection device (900) may be connected to each other by a bus (970) and communicate with each other.

[0125] The storage device (960) can store a plurality of images captured by the imaging device, and at least one image produced at each step of the inspection method according to the present invention. The images stored in the storage device (960) can be provided to at least one processor (910) when necessary during execution of the method according to the present invention.

[0126] Here, the processor (910) may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. The memory (or storage device) may be composed of at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory may be composed of at least one of a read-only memory (ROM) and a random access memory (RAM).

[0127]

[0128] The operations of the method according to an embodiment of the present invention can be implemented as a computer-readable program or code on a computer-readable recording medium. A computer-readable recording medium includes any type of recording device that stores data readable by a computer system. Furthermore, a computer-readable recording medium can be distributed across network-connected computer systems, allowing the computer-readable program or code to be stored and executed in a distributed manner.

[0129] While some aspects of the present invention have been described in the context of a device, they may also represent a description of a corresponding method, wherein a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method may also be described as a corresponding block or item or a feature of a corresponding device. Some or all of the method steps may be performed by (or using) a hardware device, such as, for example, a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, one or more of the most significant method steps may be performed by such a device.

[0130] Although the present invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A step of acquiring multiple images of the appearance of a target object at different brightness levels; A step of extracting one or more target regions within each image; A step of comparing the brightness of one or more of the above inspection target areas with a brightness threshold set for each inspection target area; and An image brightness correction method, comprising a step of calculating a brightness correction value by reflecting a target brightness to the brightness of the inspection target area according to the comparison result.

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

3. In claim 2, The step of comparing the brightness of one or more of the above inspection target areas with the brightness threshold set for each inspection target area is: An image brightness correction method, comprising a step of comparing an average brightness of an inspection target area with a lower brightness limit and an upper brightness limit set for the inspection target area.

4. In claim 3, The step of calculating the brightness correction value by reflecting the target brightness to the brightness of the inspection target area according to the above comparison result is as follows. An image brightness correction method, comprising a step of calculating the brightness correction value based on a difference value between the average brightness and the target brightness when the average brightness of the inspection target area is outside the range of the brightness lower limit value and the brightness upper limit value.

5. In claim 4, The step of calculating the brightness compensation value based on the difference value between the average brightness and the target brightness is as follows: An image brightness compensation method, comprising the step of calculating a camera exposure time adjustment value calculated by multiplying the difference between the average brightness and the target brightness by a control constant.

6. In claim 4, The step of calculating the brightness compensation value based on the difference value between the average brightness and the target brightness is as follows: When there are multiple inspection target areas included in one image and the brightness correction values ​​calculated for the multiple inspection target areas are different, An image brightness correction method, comprising a step of multiplying a control constant by the largest value among a plurality of brightness correction values ​​to derive a camera exposure time adjustment value.

7. In claim 6, An image brightness compensation method further comprising the step of providing the generated camera exposure time adjustment value to an imaging device.

8. In claim 1, An image brightness correction method, wherein the target object includes an electrode during an electrode process of a battery manufacturing process.

9. In claim 1, One or more of the above test target areas are: An image brightness correction method, comprising one or more regions among a coated region, a non-coated region, and an insulating region of an electrode, which regions are distinguished according to the properties of the regions.

10. In claim 1, Multiple images captured at different brightness levels, A first image captured at a first brightness and a second image captured at a second brightness are included, An image brightness correction method, characterized in that the second brightness is different from the first brightness.

11. In claim 1 An image brightness correction method, wherein a defect inspection of a target object being processed is performed using the brightness-corrected inspection target area.

12. A device for inspecting electrodes during the electrode process of the battery manufacturing process. at least one processor; and A memory comprising at least one instruction to be executed via at least one processor, At least one of the above commands, A command to receive multiple images of the appearance of a target object at different brightness levels from an imaging device; A command to extract one or more target regions within each image; A command to compare the brightness of one or more of the inspection target areas with a brightness threshold set for each inspection target area; and An electrode inspection device including a command to calculate a brightness compensation value by reflecting the target brightness to the brightness of the inspection target area according to the comparison result.

13. In claim 12, An electrode inspection device, wherein the brightness of the above inspection target area is set to the average brightness of pixels within the inspection target area.

14. In claim 13, A command to compare the brightness of one or more of the above test target areas with a brightness threshold set for each test target area, An electrode inspection device comprising a command to compare an average brightness of an inspection target area with a lower brightness limit and an upper brightness limit set for the inspection target area.

15. In claim 14, A command to calculate a brightness correction value by reflecting the target brightness to the brightness of the inspection target area based on the above comparison result is as follows: An electrode inspection device, comprising a command to calculate the brightness compensation value based on a difference value between the average brightness and the target brightness when the average brightness of the inspection target area is outside the range of the brightness lower limit value and the brightness upper limit value.

16. In claim 15, A command to calculate the brightness compensation value based on the difference value between the average brightness and the target brightness is as follows: An electrode inspection device, comprising a command to produce a camera exposure time adjustment value calculated by multiplying the difference between the average brightness and the target brightness by a control constant.

17. In claim 15, A command to calculate the brightness compensation value based on the difference value between the average brightness and the target brightness is as follows: When there are multiple inspection target areas included in one image and the brightness correction values ​​calculated for the multiple inspection target areas are different, An electrode inspection device comprising a command to multiply a control constant by the largest value among a plurality of brightness compensation values ​​to produce a camera exposure time adjustment value.

18. In claim 17, At least one of the above commands, An electrode inspection device further comprising a command to provide the generated camera exposure time adjustment value to the imaging device.

19. In claim 12, One or more of the above test target areas are: An electrode inspection device comprising one or more regions of a coated region, a non-coated region, and an insulating region of an electrode, which regions are distinguished according to the properties of the regions.

20. In claim 12, Multiple images captured at different brightness levels, A first image captured at a first brightness and a second image captured at a second brightness are included, An electrode inspection device, characterized in that the second brightness is different from the first brightness.

21. In claim 12, At least one of the above commands, An electrode inspection device further comprising a command to perform a defect inspection of a target object being processed using the brightness-corrected inspection target area.

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