Vision inspection apparatus for cylindrical battery

Abstract

The present invention provides a cylindrical battery vision inspection device capable of increasing the reliability of the appearance inspection process by accurately detecting defects such as scratches, dents, and bubbles present on the surface of a cylindrical battery despite positional deviations such as vibration and twisting of the cylindrical battery moving at high speed. The cylindrical battery vision inspection device includes a transfer unit, an illumination unit, an imaging unit, and a discrimination unit. The transfer unit rotates and moves the cylindrical battery. The illumination unit irradiates a line-shaped illumination light toward the side of the cylindrical battery rotating and moving in the transfer unit. The imaging unit captures the side of the cylindrical battery illuminated by the illumination light to obtain a planar scan area. The discrimination unit determines whether there is a defect on the side of the cylindrical battery from the image captured by the imaging unit.

Description

Technology Field

[0001] The present invention relates to a cylindrical battery vision inspection device, and more specifically, to a cylindrical battery vision inspection device capable of accurately detecting defects such as scratches, dents, and bubbles present on the surface of a cylindrical battery. Background Technology

[0002] Secondary batteries (hereinafter referred to as "batteries") are used embedded in mobile phones, laptops, electric vehicles, etc., and product demand has been growing rapidly in recent years. In particular, due to recent fires in electric vehicles and other incidents, customer demands for quality control regarding battery safety have increased significantly. Therefore, a final external inspection is performed before the battery is shipped, followed by a packaging process for shipment.

[0003] Visual inspection is a process for inspecting defects such as scratches, dents, and bubbles on the surface of a battery. Since these defects can reduce product reliability and cause the battery to explode, they must be detected accurately and precisely without over-inspection or mis-inspection during the visual inspection process.

[0004] Meanwhile, batteries can be classified into cylindrical batteries and prismatic batteries depending on their shape. Due to their shape, cylindrical batteries are frequently over-inspected or mis-inspected during the visual inspection process compared to prismatic batteries, resulting in many cases of defective shipments.

[0005] The visual inspection of existing cylindrical batteries is performed manually by skilled personnel, and in this case, there is a problem in that the inspection standards can vary depending on the worker's skill level and the condition at the time of inspection.

[0006] Accordingly, there is a recent trend of performing vision inspection using cameras. That is, defects such as scratches, dents, and bubbles present on the surface of a cylindrical battery are inspected from images of the cylindrical battery.

[0007] However, conventional vision inspection has a problem in that the characteristics of the captured images can vary depending on the color or material of the cylindrical battery surface, resulting in varying inspection precision and reduced compatibility depending on the type of battery.

[0008] In addition, when performing vision inspection on cylindrical batteries moving at high speed, there are issues such as delays in upstream and downstream processes or reduced efficiency of the overall manufacturing process, as the movement speed of the batteries must be slowed down to perform visual inspection on all sides of the batteries.

[0009] In addition, cylindrical batteries moving through the visual inspection section have not only high movement speeds but also minute positional deviations such as vibration or misalignment. Due to these positional deviations, the detection images obtained have low reliability, and consequently, defects on the surface of the battery are over-inspected or mis-inspected, leading to the problem of the batteries being shipped as defective. Prior art literature

[0010] Republic of Korea Published Patent Application No. 10-2025-0015677 (Published on Feb. 3, 2025) The problem to be solved

[0011] The objective of the present invention to solve the aforementioned problems is to provide a cylindrical battery vision inspection device capable of accurately detecting defects such as scratches, dents, and bubbles present on the surface of a cylindrical battery.

[0012] In addition, the objective of the present invention is to provide a cylindrical battery vision inspection device capable of significantly increasing the precision of detecting defects present on the surface of a cylindrical battery, despite positional deviations such as vibration and misalignment of the cylindrical battery while it is moving at high speed.

[0013] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0014] A cylindrical battery vision inspection device according to an embodiment of the present invention for solving the above-mentioned problem comprises: a transfer unit for rotating and moving a cylindrical battery; a lighting unit for irradiating a side of the cylindrical battery rotating and moving in the transfer unit; a shooting unit for photographing the side of the cylindrical battery irradiated with the lighting light; and a determination unit for determining whether there is a defect in the side of the cylindrical battery from the image captured by the shooting unit.

[0015] In a cylindrical battery vision inspection device according to an embodiment of the present invention, the illumination light may be a line light extending along the longitudinal direction of the cylindrical battery, and the imaging unit may include an area scan camera having a planar scan area of ​​a preset area.

[0016] In a cylindrical battery vision inspection device according to an embodiment of the present invention, the planar scan area may have a second width larger than the first width of the illumination light and a second length longer than the first length of the illumination light so that the line-shaped illumination light is disposed inside.

[0017] In a cylindrical battery vision inspection device according to an embodiment of the present invention, for a single cylindrical battery, the product of the number of planar scan areas and the second width may be greater than the circumference of the cylindrical battery.

[0018] In a cylindrical battery vision inspection device according to an embodiment of the present invention, a scan area control unit for adjusting the size of the second width may be further included. Effects of the invention

[0019] According to the present invention, defects such as scratches, dents, and bubbles present on the surface of a cylindrical battery can be accurately detected despite positional deviations such as vibration and twisting of the cylindrical battery moving at high speed, thereby increasing the reliability of the appearance inspection process.

[0020] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention. Brief explanation of the drawing

[0021] FIG. 1 is an exemplary diagram of a cylindrical battery vision inspection device according to an embodiment of the present invention. Figure 2 is an example diagram showing various positional deviations and defects of a cylindrical battery moving in Figure 1. Figure 3 is an example diagram showing the planar scan area of ​​the imaging unit corresponding to various positional deviations and defects of the cylindrical battery shown in Figure 2. Figure 4 is an example diagram illustrating the process of detecting defects in a cylindrical battery through the discrimination unit of Figure 1. Specific details for implementing the invention

[0022] The present invention will be described below with reference to the attached drawings. Of course, the present invention may be implemented in various different forms not illustrated and is not limited to the embodiments described herein. Furthermore, in order to clearly explain the present invention in the drawings, parts unrelated to the explanation have been omitted, and similar parts throughout the specification have been given similar reference numerals.

[0023] Throughout the specification, when it is stated that a part is "connected (connected, in contact, combined)" with another part, this includes not only cases where they are "directly connected," but also cases where they are "indirectly connected" with other members interposed between them. Furthermore, when it is stated that a part "includes" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion of additional components.

[0024] The terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. Additionally, singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, terms such as “comprising,” “having,” and “having” in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0025] Embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0026] FIG. 1 is an exemplary diagram of a cylindrical battery vision inspection device according to an embodiment of the present invention, FIG. 2 is an exemplary diagram showing various positional deviations and defects of a cylindrical battery moving in FIG. 1, FIG. 3 is an exemplary diagram showing a planar scan area of ​​a shooting unit corresponding to various positional deviations and defects of a cylindrical battery shown in FIG. 2, and FIG. 4 is an exemplary diagram explaining the process of detecting defects of a cylindrical battery through a discrimination unit of FIG. 1.

[0027] Referring to FIGS. 1 to 4, the cylindrical battery vision inspection device according to the present embodiment includes a transfer unit (10), a lighting unit (20), a shooting unit (30), and a discrimination unit (40).

[0028] The transfer unit (10) can rotate and move the cylindrical battery (1).

[0029] The transfer unit (10) may have a rotating unit (11), an input unit (12), and an output unit (13).

[0030] The rotating part (11) can be placed in a vision inspection area and can place a cylindrical battery (1) transferred from the input part (12) and rotate the placed cylindrical battery (1).

[0031] For example, the rotating part (11) may be provided in the form of a roll having a plurality of seating portions formed on the outer surface for seating a cylindrical battery (1), and each seating portion may be equipped with a driving roller for rotating the cylindrical battery (1). That is, when a cylindrical battery (1) inserted from the input portion (12) is seated on the seating portion of the rotating part (11), the driving roller is rotated to rotate the cylindrical battery (1) seated on the seating portion 360 degrees, and then the rotating part (11) is rotated to discharge the cylindrical battery (1) toward the output portion (13).

[0032] The input section (12) is positioned upstream of the rotating section (11), and a large number of cylindrical batteries (1) can be sequentially and continuously transported to the rotating section (11).

[0033] The discharge section (13) is positioned downstream of the rotation section (11) and can continuously discharge the cylindrical battery (1) that has completed vision inspection in the rotation section (11) to a subsequent process.

[0034] A large number of cylindrical batteries (1) can pass through the vision inspection area sequentially in a lying state through the input section (12), the rotation section (11), and the output section (13).

[0035] The lighting unit (20) can irradiate light (21) toward the cylindrical battery (1) mounted on the rotating unit (11).

[0036] The illumination light (21) may be a line light extending along the length direction of the cylindrical battery (1). The line-shaped illumination light (21) may have a first width and a first length.

[0037] Accordingly, a line-shaped light (21) can be irradiated onto the side of the cylindrical battery (1) which is placed in a lying position on the mounting part of the rotating part (11).

[0038] The shooting unit (30) can photograph the side of the cylindrical battery (1) where the illumination light (21) is irradiated while the shooting unit (30) is mounted on the rotating unit (11).

[0039] The shooting unit (30) may include an area scan camera having a planar scan area (31).

[0040] The planar scan area (31) may have a preset planar area. That is, the planar scan area (31) may have a second width (W2) that is larger than the first width of the line-shaped illumination light (21) and a second length (L2) that is longer than the first length of the illumination light (21). Accordingly, at least one line illumination light (21) may be displayed in one planar scan area (31) obtained in a single shot.

[0041] The area of ​​the planar scan area (31), that is, the second width (W2) and the second length (L2), can be appropriately adjusted and set according to the positional deviation caused by vibration and twisting of the cylindrical battery (1) present in the rotating part (11), which is the vision inspection area, and the type and size of the target defect (P).

[0042] As shown in FIG. 2 (a) and (b), the cylindrical battery (1) moving and rotating in the rotating part (11), which is the vision inspection area, may have positional deviations due to up-and-down micro-vibrations or twisting, and as shown in FIG. 2 (c), the cylindrical battery (1) may have defects (P) of various sizes (c: depth) and shapes such as scratches, dents, and bubbles.

[0043] If a line scan camera having a line scan area corresponding to a line-shaped light (21) is used, although the line scan camera has the advantage of having high resolution despite the fast movement speed of the cylindrical battery (1), as explained above, when a position deviation occurs due to vibration or twisting of the moving and rotating cylindrical battery (1), the line-shaped light (21) may move out of the line scan area, resulting in a situation where defects (P) of various sizes and types cannot be detected partially or entirely.

[0044] In contrast, as shown in FIG. 3, when using an area scan camera having a planar scan area (31), the area scan camera can always have a line-shaped illumination light (21) within the planar scan area (31) even if positional deviations occur due to vibration or twisting of the moving and rotating cylindrical battery (1), so all defects (P) of various sizes and types present on the surface of the cylindrical battery (1) can be precisely detected without over-inspection or mis-inspection.

[0045] Meanwhile, the quantity and size (area) of the planar scan area (31) captured by the shooting unit (30) for one cylindrical battery (1) can be appropriately adjusted and set based on the size and rotational movement speed of the cylindrical battery (1).

[0046] Preferably, when the size (area) of the planar scan area (31) obtained from the imaging unit (30) is preset, the product of the number of planar scan areas (31) for one cylindrical battery (1) and the second width (W2) of the planar scan area (31) can be set to be larger than the circumference of the cylindrical battery (1).

[0047] Then, even if positional deviations occur due to vibration or twisting of the cylindrical battery (1), multiple line illumination lights (21) can be displayed without omission within a single overall scan area formed by joining multiple planar scan areas (31), and accordingly, defects (P) of various sizes present on the surface of the cylindrical battery (1) can be precisely detected without over-inspection or mis-inspection. Furthermore, by optimally configuring the size (area) and number of shots of the planar scan area (31) acquired by the shooting unit (30) in correspondence with the size (circumference) of the cylindrical battery (1), the efficiency of the entire manufacturing process as well as the vision inspection process can be increased.

[0048] Meanwhile, the cylindrical battery vision inspection device may further include a scan area control unit.

[0049] The scan area control unit can adjust the size of the second width (W2) of the planar scan area (31) obtained from the imaging unit (30) according to the size (circumference) of the cylindrical battery (1), the positional deviation due to vibration or twisting, the type and size (depth) of the defect (P), etc.

[0050] For example, the scan area control unit can adjust the size of the second width (W2) of the planar scan area (31) by adjusting the optical system provided in the shooting unit (30).

[0051] Through this scan area control unit, the size (circumference) of the cylindrical battery (1), position deviation due to vibration or twisting, and the type and size (depth) of the defect (P) can be effectively managed.

[0052] The determination unit (40) can determine whether there are defects (P), such as scratches, dents, and bubbles, formed on the surface (side) of the cylindrical battery (1) from the image captured by the shooting unit (30).

[0053] First, the discrimination unit (40) can create a single overall scan area (31A) by joining multiple planar scan areas (31) obtained by multiple shots through the shooting unit (30) for a single cylindrical battery (1) rotating within the vision inspection area. Multiple line illumination lights (21) maintaining an even spacing can be displayed in the overall scan area (31A).

[0054] If there are defects (P1, P2) such as scratches, dents, or bubbles on the surface of the cylindrical battery (1), the illumination light (21) irradiated at the location may be refracted and distorted during the reflection process, and a deformation area (s1, s2) corresponding to the defects (P1, P2) may be formed in the image of the line illumination light (21) displayed in the planar scan area.

[0055] Consequently, the determination unit (40) can determine that the defect is defective if the deformation area of ​​the line illumination light (21) image exceeds a preset tolerance value (R).

[0056] For example, as shown in FIG. 4, the first defect (P1) can be determined as a minor defect unrelated to product defects, as the corresponding first deformation area (s1) in the line illumination light (21) image does not exceed the allowable error value (R). Additionally, the second defect (P2) can be determined as a serious defect directly leading to product defects, as the corresponding second deformation area (s2) in the line illumination light (21) image exceeds the allowable error value (R).

[0057] The cylindrical battery vision inspection device according to the present invention can significantly increase the reliability of the appearance inspection process by accurately detecting defects (P), such as scratches, indentations, and bubbles, present on the surface of the cylindrical battery (1) despite positional deviations such as vibration and twisting of the cylindrical battery (1) moving at high speed.

[0058] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form.

[0059] The scope of the present invention is defined by the claims set forth below, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention. Explanation of the symbols

[0060] 10: Transfer section 20: Lighting Department 30: Filming Department 40: Discrimination unit

Claims

Claim 1 A cylindrical battery vision inspection device characterized by comprising: a transfer unit for rotating and moving a cylindrical battery; a lighting unit for irradiating a light toward the side of the cylindrical battery rotating and moving in the transfer unit; a shooting unit for photographing the side of the cylindrical battery irradiated with the light; and a determination unit for determining whether the side of the cylindrical battery is defective from the image captured by the shooting unit. Claim 2 A cylindrical battery vision inspection device according to claim 1, wherein the illumination light is a line light extending along the longitudinal direction of the cylindrical battery, and the imaging unit includes an area scan camera having a planar scan area of ​​a preset area. Claim 3 A cylindrical battery vision inspection device according to claim 2, wherein the planar scan area has a second width larger than the first width of the illumination light and a second length longer than the first length of the illumination light so that the line-shaped illumination light is placed inside. Claim 4 A cylindrical battery vision inspection device according to claim 3, characterized in that, for a single cylindrical battery, the product of the number of planar scan areas and the second width is greater than the circumference of the cylindrical battery. Claim 5 A cylindrical battery vision inspection device characterized by further including a scan area control unit for adjusting the size of the second width in paragraph 3.

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