KR102539715B1 - appearance inspection apparatus for Can for Secondary battery - Google Patents

Abstract

The present disclosure relates to a device for inspecting the appearance of a secondary battery can, which can obtain an image of the appearance of the secondary battery can and determine whether there is a defect. The device for inspecting the appearance of a secondary battery can according to the present disclosure simultaneously acquires side images of a plurality of cans and can create a side image of one can by extracting an area where each can is photographed, thereby improving inspection speeds. In addition, the accuracy of defect diagnosis can be improved by irradiating light in various combinations to obtain images of the side of the can.

Description

Appearance inspection apparatus for Can for Secondary battery {appearance inspection apparatus for Can for Secondary battery}

The present invention relates to an apparatus for inspecting the appearance of a can used for manufacturing a secondary battery.

A secondary battery is a battery that converts chemical energy into electrical energy to supply power to the outside, and when discharged, receives external power and converts electrical energy into chemical energy for storage. Secondary batteries are being applied to various devices in various fields due to the development of electronic devices.

These secondary batteries are produced in various forms, and as one of the various forms, cylindrical batteries, which are conventionally commonly used forms, have been widely used to date.

Since the cylindrical secondary battery is composed of a cylindrical shape and the side surface is formed as a curved surface, performing an inspection while rotating 360 degrees is used as a general exterior inspection method.

Republic of Korea Patent Registration No. 1030449 (announced on April 25, 2011) has been disclosed for an external inspection device for such a cylindrical shape.

However, this conventional inspection method has a problem in that the inspection accuracy is low during the vision inspection of the can, and the defect rate increases after the final battery is produced.

Republic of Korea Patent No. 1030449 (Announced on April 25, 2011)

An object of the present invention is to provide a visual inspection device for a can for a secondary battery to solve the low inspection efficiency, which is a problem of a conventional can external inspection device used for a cylindrical secondary battery.

As a means for solving the above problems, according to the present invention, a secondary battery can external inspection device capable of acquiring an image according to an angle by simultaneously rotating a plurality of cans in a state in which they are arranged side by side in the width direction can be provided.

At this time, an image of the can can be obtained using light combined at various positions according to the rotation angle of the secondary battery can.

In addition, an internal image of the secondary battery can may be acquired using the pinhole inspection module, and an image of the lower surface of the can may be obtained using the lower surface inspection module.

The appearance inspection apparatus for secondary battery cans according to the present invention can increase the defect inspection rate and improve inspection speed by obtaining images for each angle of a plurality of cans and for each lighting combination. In addition, the inner and lower surface inspection modules are provided, respectively, so that the overall exterior inspection of the can can be quickly performed.

1 is a view showing a can for a secondary battery.
2 is a perspective view of an external inspection apparatus for a secondary battery can according to an embodiment of the present invention.
3 is a perspective view of a side inspection module;
4 is an operating state diagram of a side lighting unit.
5 to 13 are diagrams illustrating images acquired corresponding to angles of side lighting units and cans.
14 is a diagram illustrating a concept of generating a side inspection image by combining side object images in an image processing unit.
15 to 17 are diagrams illustrating the concept of side inspection images of multiple cans obtained by irradiating the same pattern of illumination.
18 is a diagram illustrating the concept of a plurality of inspection images of one secondary battery can obtained upon completion of one side inspection.
19 is a perspective view centering on inspection positions of a lower surface inspection module and a pinhole inspection module.
20 is a perspective view of a lower surface inspection module.
21 is a cross-sectional view illustrating an optical axis of a lower surface inspection module.
22 is a partially exploded perspective view of the lower surface inspection module.
23 is another cross-sectional view of the lower surface inspection module.
24 is an exploded perspective view of a lower surface inspection module.
25 is a cross-sectional view of a lower lighting unit.
26 is a view showing an example of a defect on the lower surface.
27 is a conceptual diagram illustrating a wide angle view of a pinhole inspection module.
28 is a view showing an image of the inside of a can taken by a pinhole inspection module.

Hereinafter, an external inspection apparatus for a can for a secondary battery according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, in the description of the following embodiments, the name of each component may be called a different name in the art. However, if they have functional similarity and identity, even if a modified embodiment is employed, it can be regarded as an equivalent configuration. In addition, signs added to each component are described for convenience of description. However, the contents of the drawings in which these symbols are written do not limit each component to the scope in the drawings. Likewise, even if an embodiment in which the configuration in the drawings is partially modified is employed, it can be regarded as an equivalent configuration if there is functional similarity and identity. In addition, in light of the level of a general technician in the relevant technical field, if it is recognized as a component that should be included, the description thereof will be omitted.

Hereinafter, the longitudinal direction in a secondary battery can refers to a height direction in a cylindrical structure, and the width direction refers to a radial direction in a cylindrical structure. In addition, the description will be made on the premise that the direction in which the can is opened is upward.

1 is a view showing a can for a secondary battery.

Referring to FIG. 1 , in the present invention, a can for a secondary battery, which is an object of appearance inspection, is used to form part of the exterior of a secondary battery. A can for a secondary battery is made of a conductive material and is configured to serve as one pole when manufacturing of the secondary battery is completed. As an example, the can can be configured to function as a negative electrode.

Referring to FIG. 1(a) , the secondary battery can 1000 may have an accommodation space therein, an opening formed at an upper side thereof, and a lower wall 1010 and a side wall 1020 may be integrally formed. Referring to FIG. 1(b) , the side wall 1020 and the lower wall 1010 may have a constant thickness. An exterior inspection of the can 1000 for secondary batteries may be performed on a surface that can be confirmed from the outside. As an example, the inner surface 1001 of the side wall and the upper surface 1003 of the lower wall are inspected as the outside of the can 1000, and the outer surface 1002 of the side wall and the lower surface 1004 of the lower wall are inspected as the inner surface of the can 1000. can In the present disclosure, the inside of the can 1000 is inspected to improve the inspection speed, that is, the inner surface 1001 of the side wall and the upper surface 1003 of the lower wall are simultaneously inspected, and the outer surface 1002 of the side wall and the lower surface 1004 of the lower wall are simultaneously inspected. ) can be checked individually.

Since the structure of the can 1000 is three-dimensionally composed of a concave inner surface, a side surface composed of a curved surface, and a flat surface, the external inspection apparatus for the can 1000 for a secondary battery according to the present disclosure includes the inner surface 1001 and 1003, the side surface ( 1002) and the image of the lower surface 1004 are obtained, respectively, and the exterior inspection is performed.

However, in the following description, the outer surface 1002 of the side wall is referred to as a side surface for convenience of description.

2 is a perspective view of an external inspection apparatus for a secondary battery can according to an embodiment of the present invention.

Referring to FIG. 2 , the external inspection apparatus 1 for a secondary battery can according to an embodiment of the present invention includes a side inspection module 100, a bottom inspection module 400, a pinhole inspection module 300, and a transfer unit 200. , It may be configured to include a control unit (not shown) and an image processing unit (not shown).

In a state where the plurality of cans 1000 are arranged side by side in the thickness direction, the side inspection module 100 simultaneously rotates the plurality of cans 1000 by 360 degrees or more around a central axis in the longitudinal direction to simultaneously capture side images of the plurality of cans 1000. configured to obtain.

The side inspection module 100 acquires side images of the plurality of cans 1000 at 0 degrees, 120 degrees, and 240 degrees, respectively, while rotating the can 1000 at predetermined angles, for example, at intervals of 120 degrees. can In this case, the side inspection module may obtain a plurality of images by different combinations of various lights from one angle, that is, by varying the number and position of light emitting units emitted from the lighting unit. This image acquisition operation is repeatedly performed while simultaneously rotating a plurality of cans at a predetermined angle. Meanwhile, the structure and function of the side inspection module will be described in detail later.

The pinhole inspection module 300 is configured to obtain an image of the inside of the can 1000 . In the case of performing an exterior inspection of the lower surface and the inner surface without changing the position of the can, the pinhole inspection module 300 is arranged to look in a direction opposite to that of the camera of the lower surface inspection module 400 . That is, in the pinhole inspection module 300 , a pinhole camera may be disposed in a direction in which an inner surface of the transported can is viewed from the upper side. A pinhole camera has a relatively smaller aperture than a typical camera and can have a wide angle. Accordingly, when the can is viewed from the top, images of the upper surface of the lower wall and the inner surface of the side wall can be simultaneously captured.

The lower surface inspection module 400 is configured to photograph the lower surface of the can 1000 . The lower surface inspection module may include an independent lighting unit and a camera module, and is configured to irradiate light toward the lower surface of the transported can and acquire an image.

The transfer unit 200 is configured to transfer cans for secondary batteries. The transfer unit 200 is configured to transport a plurality of cans from the side inspection module 100 , the bottom inspection module 400 , and the pinhole inspection module 300 to an inspection position for inspecting the can 1000 .

In FIG. 2 , the transfer unit 200 is configured to transport the cans to the inspection positions of the inspection module 400 and the pinhole inspection module 300 when the side surface inspection is completed by the side inspection module 100 . However, the positions of the above-described lower surface inspection module 400 and the pinhole inspection module 300 are merely examples, and the positions may be changed so that cans disposed at different positions may be respectively inspected.

Meanwhile, the transfer unit 200 may transfer the cans 1000 in a state in which they are arranged side by side in the width direction so as to minimize a change in posture for the external inspection.

The conveying unit 200 is divided into a plurality of sections, and the conveying speed of the can can be differently adjusted in each section. For example, in the side inspection module 100 where several cans are inspected at once, transport of the cans stops until the side surfaces of the plurality of cans are inspected. Thereafter, a plurality of cans are separated from the position of the side inspection module at once. That is, the transfer unit 200 is controlled to move as many distances as the number of side inspections at a time in a certain section. In addition, the transfer unit transfers the cans while repeating a process of transferring the cans by a predetermined distance to each other passing through the lower surface inspection module and the pinhole inspection module. That is, the lower surface inspection module and the pinhole inspection module of the transfer unit 200 may be operated in synchronization with a function of repeatedly photographing one can. On the other hand, the conveying unit 200 may have a concave support on the upper side so that each can can be seated, and cans such as a separate hand (not shown) capable of transferring cans between the conveying parts from the side inspection module 100. Various well-known configurations for smooth transfer of may be additionally provided.

After the side inspection of the plurality of cans is completed by the side inspection module 100, the transfer unit 200 may receive a plurality of cans, for example, 8 cans at a time. The transfer unit 200 then moves the can in the width direction by a predetermined distance between the lower surface inspection module 400 and the pinhole inspection module 300 . That is, the transfer unit 200 may transfer cans by the distance between the longitudinal central axes of two adjacent cans. Accordingly, even if the positions of the inspection module 400 and the pinhole inspection module 300 are not adjusted separately, the cans can be transferred to the inspection position one by one by one transfer operation of the transfer unit 200 . The transport unit 200 may include a driving unit for transport and a can seating unit. The can mounting unit may support the can in the width direction between both ends in the longitudinal direction of the can so as to prevent interference when capturing images from the upper and lower sides. On the other hand, since the configuration of the transfer unit can be configured in various ways, further detailed description will be omitted.

A controller (not shown) is configured to control each inspection module and the transfer unit 200 . The control unit may be provided on one side of the secondary battery can inspection device, and may include a well-known processor. The control unit may control an operation of the transfer unit to place each can at an accurate inspection position and an operation to acquire an image of the inspection module.

An image processing unit (not shown) is configured to process a plurality of images obtained from each inspection module. The image processing unit analyzes a plurality of images to determine whether or not there is a defect, and depending on whether or not there is a defect, the control unit can then determine an individual can transport path. In addition, it is configured to transmit information on whether or not there is a defect for each can to the central control unit.

In particular, the image processing unit may generate images for individual cans by incorporating images obtained from a side inspection module to be described later. This will be described in detail in FIGS. 5 to 19 later.

Hereinafter, the side inspection module will be described in detail with reference to FIGS. 3 to 18 .

3 is a perspective view of a side inspection module;

Referring to FIG. 3 , in one embodiment according to the present invention, a side inspection module 100 may include a hand 130 and a side vision module 110 . Here, the side vision module 110 may be provided on a vertical frame provided in a vertical direction. That is, it is configured to take pictures while looking down from the upper side of the plurality of secondary battery cans 1000 arranged side by side in the horizontal direction.

The hand 130 may be configured to simultaneously rotate the plurality of cans 1000 for secondary batteries. The hand 130 is configured to rotate the can while supporting both sides of the transfer unit, that is, both sides of the can loaded on the transfer unit in the longitudinal direction. The hands 130 may be configured as a pair on both sides of the transfer unit to be driven in synchronization with each other. The pair of hands 130 each include a gripper in contact with the can, and the pair of grippers 131 may be configured such that a distance between them can be adjusted. That is, the pair of hands 130 may be spaced apart from each other to prevent interference when the can is transported to the side inspection position or taken out after the side inspection is completed. On the other hand, while the distance between the pair of hands 130 is narrowed to rotate the can 1000 during inspection, the can 1000 is temporarily fixed and rotated by pressing the can 1000 in the longitudinal direction. However, this configuration may be modified and applied to the plurality of cans 1000 in various configurations capable of simultaneously rotating and minimizing interference for side image acquisition.

The side vision module 110 may be configured to acquire images of side surfaces of the plurality of cans 1000 for secondary batteries. The side vision module 110 is configured to acquire images of the plurality of secondary battery cans 1000 picked up on one frame 101 in a state in which the plurality of cans 1000 are aligned in one column.

The side vision module 110 may include a side camera 120 and a side lighting unit 111 . The side camera 120 has an appropriate viewing angle and may be disposed at a point separated by a predetermined distance from the inspection position where the can is picked up and disposed by the hand 130 . The side camera 120 is composed of an area camera and is configured to acquire a photographed image of an inspection position including images for about half of each can 1000 at one time. The optical axis of the side camera 120 may be set perpendicular to the arrangement direction of the cans 1000 arranged at the inspection position. That is, when the plurality of cans 1000 are arranged, the side camera 120 may be arranged such that an optical axis passes through the central position of the arrangement.

The side lighting unit 111 may be configured to radiate light to the plurality of cans 1000 picked up at the same time. The side lighting unit 111 may include a plurality of light emitting units 112 . Each light emitting unit 112 may be formed to extend in a horizontal direction. That is, the area emitted from each side lighting unit 111 may be formed in a direction perpendicular to the longitudinal direction of the picked-up can 1000 . Also, the plurality of light emitting units may be disposed side by side in a vertical direction and operate independently of each other.

The side lighting unit 111 may be disposed to radiate light in an oblique direction with respect to the arrangement direction in which the cans 1000 are picked up and arranged so as to prevent interference with the side camera 120 and appropriately radiate the irradiated light. there is. As an example, the side lighting unit 111 is formed at a predetermined distance from the inspection position, and may be disposed at an angle of 45 degrees from the central portion of the row of secondary battery cans 1000 disposed at the inspection position. However, these angles are set as examples for explanation, and may be arranged by being transformed into various angles.

Meanwhile, the controller (not shown) may be configured to control the side camera 120, the hand 130, and the side lighting unit 111. The controller may be configured to control the position of the hand 130 and the rotation of the gripper module 131 . The control unit may control the rotational operation of the gripper module 131, the operation of the side camera 120, and the operation of the side lighting unit 111 in connection with each other. The control unit controls the gripper module 131 to rotate when the inspection starts, and operates the side lighting unit 111 by synchronizing the operation of the side lighting unit 111 and the side camera 120, so that when light is irradiated to the inspection position The side camera 120 is operated and controlled to obtain a photographed image. In addition, the controller may control the side lighting unit 111 to emit light by patterning a plurality of light emitting modules in the side lighting unit 111 according to a predetermined order.

4 is an operating state diagram of a side lighting unit.

Referring to FIG. 4 , as described above, the side lighting unit 111 includes a plurality of light emitting modules, and each light emitting module may be arranged side by side in a vertical direction parallel to each other. The side lighting unit 111 may irradiate the light emitting area 113 in a pattern under the control of the controller. As an example, referring to FIG. 4(a), in the first pattern, two linear light emitting regions 113 parallel to each other are generated by simultaneously operating an uppermost light emitting module and a light emitting module spaced downward by a predetermined distance from the light emitting module. It can be. In addition, referring to FIG. 4(b), the second pattern emits light in two straight lines parallel to each other in a pair of horizontal directions, but the position of the selected light emitting module is shifted lower than the first pattern to emit light. (113) can be created. Also, referring to FIG. 4(c) , in the third pattern, a light emitting module at a position shifted downward from the above-described second pattern may be selected to generate the light emitting region 113 . In this way, the side lighting unit 111 irradiates light by switching the light emitting position in the vertical direction, and irradiates light while each light emitting position is switched in the longitudinal direction of the can 1000 being picked up, that is, in the vertical direction. The detection of defects in can be made easier.

5 to 13 are diagrams illustrating images acquired corresponding to angles of side lighting units and cans.

5 to 13 show a perspective view of a secondary battery (a), a light emitting position of the side lighting unit 111 (b), and a conceptual view of a side photographed image (c) to check the rotation angle of the picked-up can 1000, respectively. is appearing In the following drawings, description will be made on the premise that the plurality of cans 1000 are arranged in a row and picked up by the hand and then aligned at the inspection position. Also, as an example, it will be described on the premise that the number of cans for secondary batteries inspected by the side inspection module 100 described above is 8. In the captured image, from the left, the first can 1A, the second can 2A, the third can 3A, the fourth can 4A, the fifth can 5A, the sixth can 6A, It is possible to check the state in which the 7th can 7A and the 8th can 8A are arranged side by side.

First, referring to FIG. 5 , the control unit controls the gripper so that eight cans picked up can rotate. When the rotation starts or before the rotation starts, the side lighting unit 111 selects the light emitting area 113 according to the above-described first pattern and irradiates light to the inspection position. A first captured image 1110 in which half of is obtained.

Referring to FIG. 6 , after obtaining a first captured image 1110, the controller shifts the side lighting unit 111 in a second pattern to select a light emitting area 113 and emits light to generate a second captured image 1120. ) is obtained. In the second image, images of the first can 1B to the eighth can 8B can be confirmed, respectively.

Referring to FIG. 7 , after acquiring the second captured image, the controller shifts the lighting pattern of the side lighting unit 111 from the second pattern to the third pattern to obtain a third captured image 1130 in a state in which light is irradiated thereon. will do Also in the third image, images of the first can 1C to the eighth can 8C can be checked.

Meanwhile, the photographing interval described with reference to FIGS. 5 to 7 may be performed at intervals of several ms or μs. Meanwhile, since the rotational speed of the gripper module 131 is relatively slow, even if the first captured image 1110 to the third captured image 1130 are captured while the gripper module 131 rotates the can 1000, The area to be photographed becomes almost the same as that of photographing in a substantially still state.

Then, the control unit operates the gripper module 131 to rotate the picked up cans at a predetermined angle. For example, the predetermined angle may be 120 degrees. Since the circular can is captured as a flat image, it is difficult to obtain an accurate image of the outer portion of the cylindrical shape due to the limitation of the viewing angle. Therefore, an image is obtained by moving the image as much as an area where an accurate image can be obtained. In other words, the captured image is an image of 180 degrees, which is about half of the can, but it is difficult to accurately judge with the outer image. do. However, this is just an example. In order to increase accuracy, the shooting position may be rotated at intervals of 90 degrees or, more frequently, 60 degrees, 45 degrees, 30 degrees, or the like, depending on the rotation angle. Hereinafter, a case where it is set to rotate 120 degrees and acquire side images three times will be described.

Referring back to FIGS. 8 and 10 , after rotating the can 1000 clockwise by 120 degrees, similarly to FIGS. A fourth captured image 1140 , a fifth captured image 1150 , and a sixth captured image 1160 may be generated.

Next, referring to FIGS. 11 to 13, the gripper module 131 is operated to rotate each of the plurality of cans by 120 degrees, and then the seventh captured image 1170 and the eighth captured image 1170 are changed while changing the lighting pattern as described above. A captured image 1180 and a ninth captured image 1190 may be generated.

On the other hand, three examples of the first pattern, the second pattern, and the third pattern are exemplified as an example of the operation of the above-described side lighting unit 111, that is, shifting, but it is applicable by reducing or increasing the number of patterns. For example, shifting can be performed while converting the pattern into four types and converting it in the lower direction. In this case, as many inspection images as the number of patterns may be acquired at the rotational position of the can.

Hereinafter, with reference to FIGS. 14 to 18, a process of generating an inspection image for inspecting the side of a can by the image processing unit will be described.

14 is a diagram illustrating a concept of generating a side inspection image by combining side object images in an image processing unit.

Referring to FIG. 16 , the image processing unit may generate a side inspection image after receiving a captured image obtained from the side camera 120 . In each photographed image, an image of a portion of side surfaces of a plurality of cans may be obtained. At this time, the predetermined area adjacent to the boundary on both sides of the photographed image is difficult to check as an image, except for this, the image for the predetermined area is extracted centering on the axis of left and right symmetry. The image processing unit extracts the object image area 1200 in which each can is photographed from one photographed image. The image processing unit extracts the object image area 1200 for all captured images 1110, 1120, 1130, 1140, 1150, 1160, 1170, 1180, and 1190. Accordingly, the extracted object image area may be determined by multiplying the number of captured images and the number of picked-up cans.

Based on the example described with reference to FIGS. 5 to 13 described above, the image processing unit may extract 72 object image areas.

15 to 17 are diagrams illustrating the concept of side inspection images of multiple cans obtained by irradiating the same pattern of illumination.

After the image processing unit extracts each object image area, the images are combined and synthesized according to each lighting pattern, each can, and the rotation angle of the can.

Referring to FIG. 15 , the image of the first can captured according to the first pattern is obtained by sequentially combining images of rotation angles of 1A at 0 degrees, 1D at 120 degrees, and 1G at 240 degrees. A side inspection image 1300 for is generated.

The process of generating the side inspection images described above is applied to the first to eighth cans, and eight side inspection images captured by selecting the light emitting region 113 as the first pattern are generated. For convenience of explanation, FIG. 16 shows a first can side inspection image 1311 of the first pattern, a second can side inspection image 1312 of the first pattern, and an eighth can side inspection image of the first pattern ( 1318) is shown.

Referring to FIG. 16 , when the side lighting unit 111 selects the light emitting area 113 in a second pattern and irradiates light, a side inspection image of each can is shown. In this drawing, for convenience of description, a first can side inspection image 1321 of the second pattern, a second can side inspection image 1322 of the second pattern, and an eighth can side inspection image of the second pattern ( 1328) is shown.

Referring to FIG. 17 , when the side lighting unit 111 selects the light emitting area 113 in a third pattern and irradiates light, a side inspection image of each can is shown. In this drawing, for convenience of description, a first can side inspection image 1331 of a third pattern, a second can side inspection image 1332 of a third pattern, and an eighth can side inspection image of a third pattern ( 1338) is shown.

18 is a diagram illustrating the concept of a plurality of inspection images of one secondary battery can obtained upon completion of one side inspection.

Referring to FIG. 18 , three side inspection images generated for the first can are shown. For ease of understanding, the pattern of the lighting unit 111 and the obtained side inspection image are shown at the same time.

18(a) shows an inspection image 1311 of the first can with respect to the first pattern, FIG. 20(b) shows an inspection image 1321 of the first can with respect to the second pattern, and FIG. 20(c) shows the inspection image 1321 of the first can. An inspection image 1331 of a first can for three patterns is shown. As a result, it is possible to obtain a side inspection image for the entire completed side surface by extracting the object image area for each can from the side photographed image and combining them. In addition, it is possible to obtain an inspection image when light is irradiated by shifting the pattern of illumination.

Based on this, the image processing unit can perform a side appearance inspection of each can and determine whether or not there is a defect.

In addition, since a plurality of cans can be simultaneously arranged and photographed and images of the side surfaces of the plurality of cans can be simultaneously acquired, the speed of side appearance inspection can be dramatically improved.

Hereinafter, the inspection module will be described in detail with reference to FIGS. 19 to 25 .

19 is a perspective view of a lower surface inspection module.

Hereinafter, the inspection module will be described in detail with reference to FIGS. 19 to 25 .

19 is a perspective view centering on inspection positions of a lower surface inspection module and a pinhole inspection module.

Referring to FIG. 19 , similar to the pinhole inspection module 300 and the lower surface inspection module 400 in the present invention, it is configured to acquire an image of the inside of the can 1000 from the side of the transfer unit 200 .

The pinhole inspection module 300 includes a pinhole lighting unit and a pinhole camera, and is configured such that the pinhole lighting unit 301 radiates light into the can and acquires an image of the inside of the can.

The lower surface inspection module 400 may be provided on a side surface of the transport unit 200 so that an image can be acquired while looking at the lower surface when the can 1000 is arranged and loaded on the transport unit 200 .

Meanwhile, the lower surface inspection module 400 may be configured to be movable in a horizontal direction by being connected to an external frame. As an example, a horizontal driving unit (not shown) may be provided on the outer frame so that the position of the inspection module can be adjusted. Therefore, if the conveying unit 200 moves the cans step by step and precisely, it can help to obtain an accurate image of the lower surface by adjusting the position of the inspection module in the horizontal direction.

Similar to the lower surface inspection module 400, the pinhole inspection module 300 may be configured to move a predetermined distance in the same direction as the transport direction of the can. Accordingly, an image may be obtained by adjusting a precise horizontal position along with the movement of the can 1000 by the transfer unit.

The control unit may control the operation of the pinhole inspection module 300 and the transfer unit 200 together. That is, the cans are moved one step at a time and the cans are sequentially placed at the inspection position of the pinhole inspection module. In this case, the pinhole inspection module is driven every time the can is transported to the inspection position, so that an image can be obtained. Similarly, the lower surface inspection module can obtain an image of the lower surface when the can is newly transported to the inspection position.

20 is a perspective view of a lower surface inspection module.

The lower surface inspection module 400 may be provided on the side of the conveying unit so as to acquire an image while looking at the lower surface when cans are arranged and loaded in the conveying unit.

The lower surface inspection module may include a lower surface lighting unit 430 disposed toward the front, that is, a can, and a lower surface camera, and may include a case 450 surrounding the lower surface camera.

21 is a cross-sectional view illustrating an optical axis of a lower surface inspection module.

Referring to FIG. 21 , the lower surface inspection module 400 may include a lower surface lighting unit 430 and a lower surface camera. The lower surface inspection module 400 irradiates light from the lower surface lighting unit 430 in various combinations to radiate light to the lower surface of the can, thereby obtaining an image in which defects are more accurately displayed. The can may be horizontally moved by the transfer unit in a state of lying in the longitudinal direction and transferred to an inspection position of the bottom inspection module. The center of the lower surface of the can may be aligned with the center of the optical axis of each light. The light irradiated by the lower surface lighting unit 430 is irradiated toward the inspection position P, and in a state in which the light is irradiated, the lower surface inspection module 400 may directly acquire an image of the lower surface of the secondary battery can.

22 is a partial exploded perspective view of the lower surface inspection module 400, FIG. 23 is a cross-sectional view of the lower surface inspection module, FIG. 24 is an exploded perspective view of the lower surface inspection module, and FIG. 25 is a cross-sectional view of the lower surface lighting unit.

Referring to FIGS. 22 to 25 , the lower surface inspection module 400 may be configured to acquire images of inspection positions spaced apart by a predetermined distance on the optical axis.

The lower surface inspection module 400 may include a lens module 410, an image sensor module 420, and a lower surface lighting unit 430, and a case 450 surrounding the lens module 410 and the image sensor module 420. ).

The lens module 410 is configured to change the focal length when acquiring an image of a subject, that is, an object in an inspection position. The lens module 410 may include one or more lens kits. The lens is configured to change the focal length, and may be configured of, for example, a polymer lens. When the polymer lens is provided, the shape of the lens itself is changed by an external force so that the focal length can be adjusted. In this case, a focal distance adjusting unit (not shown) may be included so that the shape can be changed by transmitting force to the polymer lens.

The image sensor module 420 may be configured to generate an electrical signal by photographing a subject. However, since a widely used configuration may be applied to the image sensor module 420, further detailed description thereof will be omitted.

The lower surface lighting unit 430 may be configured to irradiate various types of light to an object. Since objects are composed of various shapes and materials, there may be defects that cannot be determined by any one lighting method according to optical characteristics such as reflectance and shadow. Accordingly, the lower surface lighting unit 430 irradiates a variety of optically different lights, such as the angle and amount of light, to check whether or not there is a defect in the exterior, and to improve the accuracy of whether or not there is a defect.

The bottom lighting unit 430 may include a plurality of light sources to irradiate various lights. As an example, the lower lighting unit 430 may include a lighting frame 440, a coaxial lighting unit 431, a fiber lighting unit 433, a dome lighting unit 437, and oblique lighting units 438 and 439. The bottom lighting unit 430 may be configured rotationally symmetrically with respect to the optical axis as a whole. In addition, the plurality of lighting units provided in the lower surface lighting unit 430 may be divided into a plurality of areas along the rotation direction, and operation of each lighting unit 430 may be independently determined. As an example, the area may be divided and controlled at intervals of 90 degrees along the rotation direction around the optical axis. Meanwhile, in some cases, it may be controlled to irradiate light by operating lighting units provided in two areas spaced apart from each other by 180 degrees.

The lighting frame 440 is a base on which various lighting units to be described later can be provided. The illumination frame 440 may be configured in the form of a cone having one side adjacent to the lens module 410 and the other side adjacent to the inspection position and having a wider radius as it approaches the inspection position. The light frame 440 may form a hollow having a predetermined diameter at the center side to form an optical path. The lighting frame 440 may be configured in a rotationally symmetrical shape with respect to the aforementioned optical axis.

On the other hand, at least two cutting surfaces may be provided on the inner surface of the lighting frame 440 so that the lighting unit can be disposed at various angles. The at least two cutting surfaces are configured to have different angles from the inspection position, and the lighting unit disposed on each cutting surface can irradiate light to the inspection position at different angles. Meanwhile, a domed reflective surface 441 may be provided on one side of the lighting frame. The dome-shaped reflective surface 441 is configured such that the light irradiated from the dome lighting unit 437, which will be described later, is reflected by the dome-shaped reflective surface 441 and then reaches the inspection position.

The coaxial illumination unit 431 is configured to irradiate light along the same optical axis as the optical axis through which the image sensor module 420 acquires an image. The coaxial lighting unit 431 may be provided on one side of the aforementioned lighting frame 440 and may be configured to emit light in a direction perpendicular to the aforementioned coaxial lighting unit.

A beam splitter 432 may be provided at a point where an optical path of the coaxial lighting unit 431 and an optical axis of the lens module 410 meet. The beam splitter 432 may be configured to pass light from the inspection position toward the lens module 410 and reflect light emitted from the coaxial lighting unit 431 to be directed to the inspection position.

The fiber lighting unit 433 is provided with a light source 435 on one side so as to generate a greater amount of light than other lighting units, and a plurality of optical fibers penetrating the lighting frame 440 from the light source 435 and having one end exposed to the inside. It can be configured to include. A plurality of optical fibers 436 disposed along one circular path may constitute a bundle and be connected to the light source 435 .

The fiber lighting unit 433 may include a first fiber lighting unit 433 and a second fiber lighting unit 434 having different diameters of circular paths at which ends are disposed. Here, the first fiber lighting unit 433 and the second fiber lighting unit 434 refer to portions of the optical fiber bundle that are exposed to the lighting frame 440 in a circular path. The first fiber lighting unit 433 may be disposed along a circular path having a smaller diameter than the second fiber lighting unit 434 .

The first fiber lighting unit 433 and the second fiber lighting unit 434 may each be connected to a light source 435 capable of generating a large amount of light. Referring to FIG. 5, as an example, two light sources 435 are provided on both left and right sides of the lens module 410, respectively, through a plurality of optical fibers 436, the first fiber lighting unit 433 and the second Light may be transmitted to the fiber lighting unit 434 . Accordingly, light can be selectively irradiated along circular paths of different diameters. However, the arrangement and number of the optical fibers 436 are only examples and may be modified and applied in various numbers and combinations.

The dome lighting unit 437 is configured to radiate light to the aforementioned dome-shaped reflective surface 441 and may be disposed along a circular path. The light irradiation direction of the dome lighting unit 437 is irradiated while looking in the opposite direction to the inspection position, and is reflected on the dome-shaped reflective surface 441 so that the light reaches the inspection position.

The inclined lighting units 438 and 439 are configured to emit light at an angle toward the inspection position. The oblique lighting unit may include a first oblique lighting unit 438 and a second oblique lighting unit 439 that emit light at different angles from the inspection position.

The first oblique lighting unit 438 may be configured to emit light at a greater angle than the second oblique lighting unit 439 to the inspection position. The first oblique lighting unit 438 and the second oblique lighting unit 439 may be respectively provided on cutting surfaces configured with different inclinations on the lighting frame 440 . The first oblique lighting unit 438 and the second oblique lighting unit 439 each form a circular path along the cutting surface, and may be configured to radiate light while enclosing the inspection position. Meanwhile, a translucent plate 442 made of a semi-transparent material may be provided adjacent to the first oblique lighting unit so that light emitted from the first oblique lighting unit 438 emits surface light.

The aforementioned coaxial lighting unit 431, the dome lighting unit 437, the first inclined lighting unit 438, and the second inclined lighting unit 439 may be composed of LEDs. The dome lighting unit 437, the first inclined lighting unit 438, and the second inclined lighting unit 439 are composed of a plurality of LEDs and may be provided on the lighting frame 440 along a rotationally symmetric path.

In addition, the bottom lighting unit 430 may select one or more of the coaxial lighting unit 431, the fiber lighting unit 433, the dome lighting unit 437, and the oblique lighting unit to obtain an image in a state in which light is irradiated. For example, one lighting unit may be selected, or a plurality of lighting units may be operated simultaneously to emit light and acquire an image.

26 is a view showing an example of a defect on the lower surface.

Referring to FIG. 26 , as a defect of a typical can 1000 , a mark D may exist regardless of the cause. In particular, since a can is generally made of a metallic material, it is difficult to check it with general lighting when it is taken by an external object. Among them, when a detailed stamping occurs, it is difficult to check with a general camera, but when photographing by irradiating light at various angles, the defect can be confirmed. However, in the case of the inspection module 400 in the present disclosure, defects can be accurately detected.

Hereinafter, the pinhole inspection module will be described with reference to FIGS. 27 to 28 .

27 is a conceptual diagram illustrating a wide angle view of a pinhole inspection module.

Referring to FIG. 27 , the pinhole inspection module 300 has a very wide angle of view because it has a small aperture unlike a general camera. Accordingly, images of the inner side of the can 1000, that is, the inner surface 1001 of the side wall and the upper surface 1003 of the lower wall can be simultaneously obtained.

The pinhole inspection module 300 may include a pinhole camera 302 and a pinhole lighting unit 301 . However, since a widely used configuration may be applied to the configuration of the pinhole inspection module 300, further detailed description will be omitted.

28 is a view showing an image of the inside of a can taken by a pinhole inspection module.

Referring to FIG. 28 , an image acquired by the pinhole inspection module 300 can obtain an image in a state in which perspective is maximized due to structural characteristics. Accordingly, images of the inner surface 1001 of the side wall and the upper surface 1003 of the lower wall are simultaneously acquired, and defects can be determined based on the acquired images.

As described above, the apparatus for inspecting the exterior of a can for secondary batteries according to the present invention can inspect defects on the exterior by acquiring images of the side, the bottom, and the inner surface, respectively, and performs side inspection on a plurality of cans. Since it can be performed at the same time, it has the effect of shortening the inspection time.

1: Appearance inspection device for cans for secondary batteries
100: side inspection module
110: lateral vision module
111: side lighting unit
112: light emitting unit
120: side camera
130: hand
140: blocking plate
200: transfer unit
300: pinhole inspection module
400: lower surface inspection module

Claims (15)

a transport unit configured to transport empty secondary battery cans in a width direction by loading them in a width direction;
a side inspection module that simultaneously irradiates light to the side surfaces of the plurality of secondary battery cans aligned and obtains a side photographed image in which the sides of the plurality of secondary battery cans appear together;
a lower surface inspection module provided adjacent to the transfer unit and configured to acquire an image of the lower surface of the can loaded on the transfer unit;
a pinhole inspection module configured to obtain an image of the inside of the secondary battery can; and
An image processing unit configured to determine defects of the can from images received from the side inspection module, the bottom inspection module, and the pinhole inspection module,
The side inspection module,
a hand configured to pick up the plurality of secondary battery cans side by side from a tray, transfer them to a side inspection position, and simultaneously adjust rotational angles of the plurality of secondary battery cans picked up;
a side lighting unit including a plurality of light emitting units configured to radiate light obliquely to side surfaces of the plurality of secondary battery cans at different positions along the longitudinal direction of the secondary battery cans picked up by the hand; and
Including; a side camera composed of an area camera capable of obtaining an area image of the side,
The side camera obtains the side image while changing a lighting pattern in which the light emitting unit of the side lighting unit is operated for each rotation angle of the plurality of cans,
the control unit,
When the plurality of secondary battery cans are rotated at a predetermined angle, the camera and the side lighting unit are controlled to acquire a plurality of side-viewing images for each lighting pattern constituted by the light emitting unit operated by switching in the longitudinal direction,
The image processing unit,
Extracting a plurality of object images, which are regions in which each of the secondary battery cans appear, from each of the side photographed images;
generating an inspection image by combining the object images photographed with the same lighting pattern among the object images of the same secondary battery can obtained at different rotation angles;
Appearance inspection apparatus for a secondary battery can configured to determine a defect on a side surface of the secondary battery can based on the inspection image. delete delete According to claim 1,
The control unit,
Appearance inspection device for secondary battery cans for synchronizing and controlling the photographing of the side camera and the light irradiation of the side lighting unit. According to claim 4,
The control unit,
Apparatus for inspecting the appearance of a secondary battery can for controlling the light emitting units to be sequentially operated along the longitudinal direction of the can. delete delete delete According to claim 1,
The side camera,
Appearance inspection device for a secondary battery can in which an optical axis is vertically disposed with respect to a direction in which the predetermined number of secondary batteries picked up are arranged. According to claim 9,
In the case of the inspection module,
an image sensor module configured to obtain an image of an inspection position when the lower surface of the can loaded in the transfer unit is photographed;
a lens module provided on an optical path between the lower inspection position and the image sensor module and configured to adjust a focal length; and
It is configured to include an upper surface lighting unit configured to irradiate light to the lower surface inspection position,
The upper surface lighting unit,
A coaxial lighting unit configured to irradiate light to an inspection position on the lower surface coaxially with the optical path;
a fiber lighting unit comprising a plurality of optical fibers provided along a circumferential path of a predetermined radius based on the central axis of the optical path;
a dome lighting unit configured to radiate light to a reflective surface provided on one side so that the reflected light is radiated to an inspection position when the lower surface;
Apparatus for inspecting the appearance of a secondary battery can comprising an inclined lighting unit configured to irradiate light by placing an inclination at the lower surface inspection position. According to claim 10,
In the case of the inspection module,
Appearance inspection device for a secondary battery can controlled to obtain an image of the lower surface of the can in a state in which at least one of the coaxial lighting unit, the fiber lighting unit, the dome lighting unit, and the inclined lighting unit is operated. According to claim 10,
The transfer unit,
Apparatus for inspecting the appearance of a secondary battery can that is controlled so that the cans passing through the lower surface inspection module are sequentially located at the lower surface inspection position one by one. According to claim 11,
The transfer unit,
Appearance inspection device for secondary battery cans that is controlled to receive the plurality of cans for which side image acquisition has been completed from the side inspection module and simultaneously transport them in the width direction of the cans. delete According to claim 1,
The pinhole inspection module may include: a pinhole lighting unit configured to irradiate light into the can; and a pinhole camera configured to acquire an image of the inside of the can.

Images