Battery monomer appearance detection device and detection method

Abstract

The invention discloses a battery monomer appearance detection device and detection method, and relates to the technical field of battery production detection, the battery monomer appearance detection device comprises a reflection piece, a partition light source and an image acquisition piece, the reflection piece is provided with a light hole, and one side of the reflection piece is provided with a diffuse reflection layer; the partitioned light sources are annularly distributed and face the diffuse reflection layer; the image acquisition piece is arranged on the side, away from the partition light source, of the reflection piece and faces the light hole. The method has the advantages of high defect recognition degree and high detection precision.

Description

Technical Field

[0001] The present application relates to the technical field of battery production inspection, and in particular to a battery cell appearance inspection device and inspection method. Background Art

[0002] During the production of battery cells, it is necessary to inspect the appearance of the battery cells. The object of appearance inspection is the outer shell of the battery cells, which is covered with a blue film. However, the current inspection methods have low accuracy in identifying defects. Summary of the invention

[0003] The main purpose of the present application is to provide a battery cell appearance inspection device and inspection method, aiming to at least improve the technical problem of low accuracy in identifying defects in the appearance of battery cells.

[0004] According to some embodiments of the present application, the present application provides a battery cell appearance inspection device, including a reflector, a partitioned light source and an image acquisition component, the reflector is provided with a light-transmitting hole, and a diffuse reflection layer is provided on one side of the reflector; the partitioned light sources are distributed in a ring shape, and the partitioned light sources are arranged toward the diffuse reflection layer; the image acquisition component is arranged on a side of the reflector away from the partitioned light source, and the image acquisition component is arranged toward the light-transmitting hole.

[0005] By providing a diffuse reflection layer on one side of the reflector, the light emitted by the partitioned light source is incident on the diffuse reflection layer, and after diffuse reflection on the diffuse reflection layer, it is incident on the battery cell through the opening. The image acquisition component is used to obtain the light reflected from the battery cell through the light-transmitting hole, thereby obtaining the image information of the battery cell surface. This embodiment can make the light after diffuse reflection incident on the battery cell, so that the light incident on the battery cell is uniform, has the ability to resist high reflection, reduces the risk of bright lines due to overexposure, resulting in unclear defect imaging, is better for defect imaging of different materials and types, can more clearly display the defects on the surface of the battery cell, and has the advantages of high defect recognition and detection accuracy.

[0006] In some embodiments, the reflector comprises a curved shell, the curved shell encloses a cavity with an opening, and the diffuse reflection layer is disposed on an inner wall surface of the cavity.

[0007] By providing a reflective member including a curved shell, light emitted from the partitioned light source can be diffusely reflected multiple times on the diffuse reflection layer on the inner wall of the curved shell, so that the light incident on the battery cell is more uniform, and defects on the surface of the battery cell can be displayed more clearly, further improving defect recognition and detection accuracy.

[0008] In some embodiments, an annular mounting plate is provided at the open end. The partitioned light source includes a plurality of independently controlled first sub-light sources, and the plurality of first sub-light sources are arranged to form an annular closed shape. When one of the first sub-light sources is in the lit state, the remaining first sub-light sources are in the dark state.

[0009] By setting that when one of the first sub-light sources is in the lit state, the remaining first sub-light sources are in the dark state, and using the photometric stereo method in the sub-video flashing technology for measurement, the image information of the surface of the battery cell can be obtained. And by arranging the plurality of first sub-light sources to form an annular closed shape, the battery cell can be irradiated from various positions, the obtained image information is more comprehensive, and the detection accuracy is higher.

[0010] In some embodiments, the mounting plate includes a first mounting area and a second mounting area provided on the outer periphery of the first mounting area. The second mounting area is connected to the curved surface shell. The partitioned light source includes a plurality of first sub-light sources and a second sub-light source. The plurality of first sub-light sources are arranged in the first mounting area and form a first light source group in an annular closed shape on the first mounting area. The second sub-light source forms a second light source group in an annular closed shape on the second mounting area, and the second light source group is arranged on the outer periphery of the first light source group.

[0011] By setting that the partitioned light source includes a plurality of first sub-light sources and a second sub-light source, the plurality of first sub-light sources are arranged in the first mounting area and form a first light source group in an annular closed shape on the first mounting area, and the second sub-light source forms a second light source group in an annular closed shape on the second mounting area, and the second light source group is arranged on the outer periphery of the first light source group. This embodiment is particularly suitable for detecting the windowed surface of the battery cell.

[0012] In some embodiments, the battery cell includes a housing and a blue film. The housing includes a windowed surface. The windowed surface includes an exposed surface and an attached surface provided on the outer periphery of the exposed surface. The blue film is attached to the attached surface. The light emitted by the first sub-light source is incident on the exposed surface, and the light emitted by the second sub-light source passes through the blue film and is incident on the attached surface.

[0013] By setting that the light emitted by the first sub-light source is incident on the exposed surface and the light emitted by the second sub-light source passes through the blue film and is incident on the attached surface, this embodiment is particularly suitable for detecting the windowed surface of the battery cell.

[0014] In some embodiments, the light emitted by the first sub-light source is visible light, and the light emitted by the second sub-light source is infrared light.

[0015] By setting the light emitted by the first sub-light source as visible light and the light emitted by the second sub-light source as visible light, it can be more applicable to the detection of the window surface of the battery cell.

[0016] In some embodiments, the first light source group is distributed in a runway shape, a rectangle, an ellipse or a circle, and / or, the second light source group is distributed in a runway shape, a rectangle, an ellipse or a circle.

[0017] By reasonably setting the distribution forms of the first sub-light source and the second sub-light source, it is beneficial to irradiate the battery cell from various positions, which is beneficial to obtaining the image information of the surface of the battery cell.

[0018] In some embodiments, the first installation area includes a plurality of sub-areas that are connected end to end and have equal areas. Each of the sub-areas is provided with one of the first sub-light sources. The first sub-light source includes a plurality of lamp beads, and the number of the lamp beads of the plurality of first sub-light sources is the same.

[0019] By setting the first installation area to include a plurality of sub-areas with equal areas and the number of lamp beads of the first sub-light source in each sub-area being the same, it ensures that the illumination intensity of each sub-area is uniform and equal, which is beneficial to obtaining image information with uniform exposure and improving the accuracy of recognition.

[0020] In some embodiments, the second sub-light source and each of the first sub-light sources are sequentially and cyclically lit, wherein, when one of the first sub-light sources is in the lit state, the second sub-light source and the remaining first sub-light sources are in the dark state; or, when the second sub-light source is in the lit state, all of the first sub-light sources are in the dark state.

[0021] By controlling the second sub-light source and each of the first sub-light sources to be sequentially and cyclically lit, it is convenient to obtain the image information of the surface of the battery cell.

[0022] In some embodiments, the battery cell appearance detection device further includes a controller, and the controller is used to control the second sub-light source and each of the first sub-light sources to be sequentially lit and extinguished according to the time-sharing stroboscopic logic.

[0023] By setting the controller to sequentially light and extinguish multiple first sub-light sources and second sub-light sources according to the time-sharing stroboscopic logic, it is convenient to obtain the image information of the battery cell. In some embodiments, the battery cell appearance detection device further includes a housing and a mounting bracket mounted on the housing. The mounting bracket is used to mount the image acquisition member, and the image acquisition member is movably mounted on the mounting bracket, and the position of the image acquisition member on the mounting bracket can be adjusted to facilitate obtaining the image information. The mounting hole and the through hole are arranged back to back and communicate with each other. The curved surface shell is mounted on the mounting hole. Specifically, the open edge of the curved surface shell is mounted on the through hole. The light-transmitting hole and the through hole are correspondingly arranged, and the image acquisition member is correspondingly arranged with the through hole, so that the light emitted from the light-transmitting hole can be emitted to the image acquisition member through the through hole, facilitating the image acquisition member to obtain the image information of the battery cell.

[0024] By setting the curved surface shell to be mounted on the mounting hole, and the opening of the curved surface shell facing away from the through hole, the light-transmitting hole corresponding to the through hole, the image acquisition member being movably mounted on the mounting bracket and corresponding to the through hole, the housing provides a mounting position for the curved surface shell and does not hinder the propagation of light, facilitating the image acquisition member to obtain the light reflected by the battery cell, and then obtaining the image information of the battery cell, which can facilitate the subsequent identification of defects in the battery cell.

[0025] In some embodiments, the mounting bracket includes a base plate, a first sliding plate, a second sliding plate and a rotating plate. The base plate is mounted on the housing, the first sliding plate is slidably mounted on the base plate, the second sliding plate is slidably mounted on the first sliding plate, the sliding direction of the first sliding plate is perpendicular to the sliding direction of the second sliding plate, the rotating plate is mounted on the second sliding plate and can rotate relative to the second sliding plate, and the image acquisition member is mounted on the rotating plate.

[0026] By setting the first sliding plate and the second sliding plate with perpendicular sliding directions, the position of the image acquisition member on the horizontal plane can be adjusted, and by setting the rotating plate, the angle of the image acquisition member can be adjusted.

[0027] According to some embodiments of the present application, the present application provides a method for detecting the appearance of a battery cell, which is applied to the battery cell appearance detection device described above. The method for detecting the appearance of a battery cell includes the following steps: Controlling multiple first sub-light sources of the partitioned light source to be sequentially and cyclically lit according to the time-sharing stroboscopic logic; when one of the first sub-light sources is in the lit state, the rest of the first sub-light sources are in the dark state, and the light emitted by the first sub-light source is incident on the diffuse reflection layer of the curved surface shell; Controlling the image acquisition member to obtain the image information of the surface of the battery cell.

[0028] By controlling multiple first sub-light sources of the partitioned light source to be sequentially and cyclically lit according to the time-division strobing logic, and the light emitted by the first sub-light sources is incident on the diffuse reflection layer of the curved surface shell, and controlling the image acquisition component to obtain the image information of the surface of the battery cell, it is possible to make the light after diffuse reflection incident on the battery cell, so that the light incident on the battery cell is uniform, having the ability to resist high reflectivity, reducing the risk of bright lines due to overexposure, resulting in unclear defect imaging, and having better imaging for defects of different materials and types, being able to more clearly display the defects on the surface of the battery cell, and having the advantages of high defect recognition and detection accuracy.

[0029] In some embodiments, the partitioned light source further includes a second sub-light source. Multiple first sub-light sources surround and form a first light source group in a circular closed shape, and the second sub-light source surrounds and forms a second light source group in a circular closed shape. The second light source group is arranged on the outer periphery of the first light source group; the battery cell includes a housing and a blue film. The housing includes a window surface, and the window surface includes an exposed surface and an attachment surface arranged on the outer periphery of the exposed surface, and the blue film is attached to the attachment surface; the step of controlling multiple first sub-light sources of the partitioned light source to be sequentially and cyclically lit according to the time-division strobing logic includes: Controlling the second sub-light source and multiple first sub-light sources to be lit and extinguished according to the time-division strobing logic; wherein, When one of the first sub-light sources is in the bright state, the second sub-light source and the other first sub-light sources are in the dark state; or, When the second sub-light source is in the bright state, each of the first sub-light sources is in the dark state.

[0030] The above embodiments of the present application are particularly suitable for detecting the window surface of the battery cell, and due to the uniform light, the obtained image has a high recognition degree of defects.

[0031] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically lists the specific embodiments of the present application. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0033] Figure 1 It is a schematic exploded view of a battery device according to some embodiments of the present application; Figure 2 Schematic diagram of the three-dimensional structure of a perspective of the battery cell appearance detection device according to some embodiments of the present application; Figure 3 Schematic diagram of the three-dimensional structure of another perspective of the battery cell appearance detection device according to some embodiments of the present application; Figure 4 Schematic diagram of the structure of the light source assembly of the battery cell appearance detection device according to some embodiments of the present application; Figure 5 Schematic diagram of a structure of the mounting plate and the partitioned light source of the battery cell appearance detection device according to some embodiments of the present application; Figure 6 Schematic diagram of a comparison of the battery cell image obtained by the battery cell appearance detection device according to some embodiments of the present application with the related art; Figure 7 Schematic diagram of another comparison of the battery cell image obtained by the battery cell appearance detection device according to some embodiments of the present application with the related art; Figure 8 Schematic diagram of yet another comparison of the battery cell image obtained by the battery cell appearance detection device according to some embodiments of the present application with the related art; Figure 9 Schematic diagram of a structure of the curved surface shell of the battery cell appearance detection device according to some embodiments of the present application; Figure 10 Schematic diagram of the structure of the mounting plate of the battery cell appearance detection device according to some embodiments of the present application; Figure 11 Schematic diagram of another structure of the mounting plate and the partitioned light source of the battery cell appearance detection device according to some embodiments of the present application; Figure 12 Schematic diagram of yet another structure of the mounting plate and the partitioned light source of the battery cell appearance detection device according to some embodiments of the present application; Figure 13 Schematic diagram of still another structure of the mounting plate and the partitioned light source of the battery cell appearance detection device according to some embodiments of the present application; Figure 14 Comparison diagram of the image information of the window surface of the battery cell obtained by the battery cell appearance detection device according to some embodiments of the present application with the related art; Figure 15 Schematic diagram of another structure of the curved surface shell of the battery cell appearance detection device according to some embodiments of the present application; Figure 16 Schematic diagram of the structure of the image acquisition member and the mounting bracket of the battery cell appearance detection device according to some embodiments of the present application; Figure 17 Flow chart of the battery cell appearance detection method according to the first embodiment of the present application; Figure 18 This is a schematic flowchart of the method for detecting the appearance of a battery cell according to the second embodiment of the present application.

[0034] Explanation of the reference numerals in the accompanying drawings: 100, battery device; 10, box body; 20, battery cell; 11, upper cover; 12, bottom; 13, window surface; 131, exposed surface; 14, blue film; 15, edge. 200, battery cell appearance detection device; 220, image acquisition component; 230, housing; 2, partitioned light source; 21, first sub-light source; 22, second sub-light source; 3, mounting plate; 31, first mounting area; 32, second mounting area; 33, opening; 40, reflector; 4, curved shell; 41, connecting plate; 42, light-transmitting hole; 5, mounting bracket; 51, base plate; 511, first slide rail; 52, first slide plate; 521, second slide rail; 53, second slide plate; 54, rotating plate; 6, through hole; 7, diffuse reflection layer.

[0035] The realization of the purpose, functional features, and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0036] Next, the technical solutions in this embodiment will be clearly and completely described with reference to the accompanying drawings in this embodiment. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0037] It should be noted that all directional indications (such as up, down, left, right, front, back...) in this embodiment are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0038] In addition, the descriptions such as "first" and "second" in the present application are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0039] In this application, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integral; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In addition, the technical solutions between various embodiments of this application can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit this application.

[0041] In this application, the descriptions of directions such as "up", "down", "front", "back", "left", and "right" are based on the directions shown in the drawings, and are only used to explain the relative positional relationship between components in the posture shown in the drawings. If this specific posture changes, the directional indication will also change accordingly.

[0042] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydraulic, thermal, wind, and solar power stations, but also widely used in electric transportation such as electric bicycles, electric motorcycles, and electric vehicles, as well as in many fields such as aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also continuously increasing.

[0043] During the production and manufacturing of battery cells, it is necessary to detect the appearance of the battery cells. The object of the appearance detection is the outer shell of the battery cell, and a blue film is coated on the outer surface of the outer shell. However, the current detection means have a low accuracy in identifying defects.

[0044] After careful research, the applicant found that in the related technology, time-sharing stroboscopic technology is generally used to illuminate the outer shell of the battery cell from various positions with a strip light source, and then the image of the outer shell is captured by a camera for defect identification. As for how to improve the recognition accuracy of outer shell defects. Those skilled in the art have always believed that this is due to the low resolution of the camera, so most people have been committed to how to use higher resolution cameras. It is true that although the use of high-resolution cameras can increase the accuracy of defect identification to a certain extent, the improvement range is limited, and the use of high-resolution cameras means higher production and maintenance costs. There are also some people who are committed to how to increase the intensity of light, because according to the inertial thinking of those skilled in the art, generally low resolution means low clarity, and they all think about how to increase the intensity of light.

[0045] However, after further careful research, the applicant found that there is a big deviation in the direction of attention of technical personnel in this field. Since the shell of the battery cell is generally made of metal material, which has a strong ability to reflect light, the image captured by the camera has a high brightness in some parts. Under high brightness, some defects are covered up. For example, bright lines may appear on the edges of the shell due to overexposure, and if there are defects on the edges, it is difficult to identify them. This reason has not been discovered by technical personnel in this field.

[0046] In order to overcome the technical problem that defects cannot be identified due to high image brightness in some positions, the present application provides a battery cell appearance inspection device, including a reflector, a partitioned light source and an image acquisition component, the reflector is provided with a light-transmitting hole, and a diffuse reflection layer is provided on one side of the reflector; the partitioned light sources are distributed in a ring shape, and the partitioned light sources are arranged toward the diffuse reflection layer; the image acquisition component is arranged on the side of the reflector away from the partitioned light source, and the image acquisition component is arranged toward the light-transmitting hole. The present application can make the light after diffuse reflection incident on the battery cell, so that the light incident on the battery cell is uniform, has the ability to resist high reflection, reduces the risk of unclear defect imaging due to bright lines appearing due to overexposure, and has the advantages of high defect recognition and detection accuracy.

[0047] Please refer to Figure 1 , Figure 1Exploded structural schematic diagram of a battery device provided by some embodiments of the present application. The battery device 100 includes a box body 10 and battery cells 20, and the battery cells 20 are accommodated in the box body 10. Among them, the box body 10 is used to provide an accommodation space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include an upper cover 11 and a bottom 12, the upper cover 11 and the bottom 12 are covered with each other, and the upper cover 11 and the bottom 12 jointly define an accommodation space for accommodating the battery cells 20. The bottom 12 may be a hollow structure with one end open, and the upper cover 11 may be a plate-like structure. The upper cover 11 is covered on the open side of the bottom 12 so that the upper cover 11 and the bottom 12 jointly define an accommodation space; the upper cover 11 and the bottom 12 may also both be hollow structures with one side open, and the open side of the upper cover 11 is covered on the open side of the bottom 12. Of course, the box body 10 formed by the upper cover 11 and the bottom 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0048] The battery device 100 mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing electric energy. The battery cell assembly may include a plurality of battery cells 20, and the plurality of battery cells 20 are connected in series, parallel or in a hybrid connection through a busbar component.

[0049] In some embodiments, the battery cell assembly is usually formed by arranging a plurality of battery cells 20.

[0050] As an example, the battery cell assembly may be a battery module, and the battery module is formed by arranging and fixing a plurality of battery cells 20 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 20 with a cable tie.

[0051] In some embodiments, the battery device 100 may be a battery pack, and the battery pack includes a box body 10 and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body 10.

[0052] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body 10 by fixing the battery module in the box body 10.

[0053] As an example, the battery cell assembly may also be accommodated in the box body 10 by directly fixing a plurality of battery cells 20 to the box body 10.

[0054] In the battery device 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery device 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery device 100 may also include other structures, for example, the battery device 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0055] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0056] Reference Figures 2 - 5 and Figure 15 According to some embodiments of the present application, the present application provides a battery cell appearance inspection device 200, including a reflector 40, a partitioned light source 2 and an image acquisition component 220, the reflector 40 is provided with a light-transmitting hole 42, and a diffuse reflection layer 7 is provided on one side of the reflector 40; the partitioned light sources 2 are distributed in a ring shape, and the partitioned light sources 2 are arranged toward the diffuse reflection layer 7; the image acquisition component 220 is arranged on a side of the reflector 40 away from the partitioned light source 2, and the image acquisition component 220 is arranged toward the light-transmitting hole 42.

[0057] The battery cell appearance inspection device 200 is used to inspect the appearance defects of the battery cell 20. The partitioned light source 2 refers to a light source divided into multiple independently controlled parts, and each part of the partitioned light source 2 distributed in a ring can be cycled and lit in sequence. For example, the light source is divided into multiple first sub-light sources 21, and the lighting parameters of the first sub-light source 21 in each area can be individually adjusted by programming, such as by circuit or software control, and the light brightness or brightness can be adjusted by partition.

[0058] The reflector 40 is a component that can reflect the light of the partitioned light source 2. The partitioned light source 2 is arranged toward the diffuse reflection layer 7, which means that the light emitted by the partitioned light source 2 will first be incident on the diffuse reflection layer 7, and the diffuse reflection layer 7 can make the light incident thereon diffusely reflected on its surface. The diffuse reflection layer 7 can be formed by coating a diffuse reflection material on one side of the reflector 40, or by roughening one side of the reflector 40. During detection, the battery cell 20 and the image acquisition component 220 are arranged on both sides of the reflector 40, and the battery cell 20 is arranged on the reflection path of the light reflected by the diffuse reflection layer 7. The light emitted by the partitioned light source 2 is diffusely reflected on the diffuse reflection layer 7 and then incident on the battery cell 20.

[0059] The image acquisition component 220 can be a camera or a video camera, and can obtain image information by taking pictures. Specifically, the image acquisition component 220 is located on the side of the reflector 40 away from the diffuse reflection layer 7, and the image acquisition component 220 is arranged corresponding to the light-transmitting hole 42. The light reflected from the battery cell 20 can be incident on the image acquisition component 220 through the light-transmitting hole 42. The image acquisition component 220 is used to obtain the reflected light of the battery cell 20 to obtain the image information of the surface of the battery cell 20, and the image information can be used to analyze and identify the defects on the surface of the battery cell 20.

[0060] The optical path of the present application is as follows: the light emitted from the partitioned light source 2 is emitted toward the diffuse reflection layer 7, and after diffuse reflection occurs on the diffuse reflection layer 7, uniform light is formed to be incident on the surface of the battery cell 20. After being reflected by the surface of the battery cell 20, at least part of the light is emitted toward the reflector 40. The image acquisition component 220 can obtain the light reflected by the battery cell 20 through the light-transmitting hole 42, thereby obtaining image information of the surface of the battery cell 20, thereby realizing the acquisition of image information.

[0061] In the above embodiment, by providing a diffuse reflection layer 7 on one side of the reflector 40, the light emitted by the partition light source 2 is incident on the diffuse reflection layer 7, and is incident on the battery cell 20 after being diffusely reflected on the diffuse reflection layer 7. The image acquisition component 220 is used to obtain the light reflected from the battery cell 20 through the light-transmitting hole 42, thereby obtaining the image information of the surface of the battery cell 20. This embodiment can make the light after diffuse reflection incident on the battery cell 20, so that the light incident on the battery cell 20 is uniform, has the ability to resist high reflection, reduces the risk of unclear defect imaging due to bright lines due to overexposure, is better for defect imaging of different materials and types, can more clearly display the defects on the surface of the battery cell 20, and has the advantages of high defect recognition and detection accuracy.

[0062] Reference Figure 9 and Figure 15 In some embodiments, the reflector 40 includes a curved shell 4, which encloses a cavity with an opening, and a diffuse reflection layer 7 is provided on the inner wall surface of the cavity.

[0063] The curved surface shell 4 refers to a shell with a curved surface shape. The light-transmitting holes 42 are provided on the shell wall of the curved surface shell 4. The curved surface shell 4 is not a closed shell but has an opening. Specifically, the opening faces the concave side of the curved surface shell 4, and the image acquisition member 220 is arranged on the convex side of the curved surface shell 4. A diffuse reflection layer 7 is provided on the inner wall surface of the curved surface shell 4. Specifically, the diffuse reflection layer 7 can cover the entire inner wall surface of the curved surface shell 4. The specific shape of the curved surface shell 4 can be arched or hemispherical. The curved surface shell 4 is provided with light-transmitting holes 42 communicating with the cavity. In some specific embodiments, the curved surface shell 4 can be a dome structure. The dome structure mentioned here can be an arch-shaped structure or a structure of a partial cylindrical surface, such as a structure formed by making a section through the central axis of a cylinder. Setting the dome structure can enable the light incident from the partitioned light source 2 to the diffuse reflection layer 7 to form multiple reflections on the curved surface, making the light incident on the battery cell 20 more uniform and incident on the battery cell 20 from more directions.

[0064] Next, the image obtained by the image acquisition member 220 is compared with the image obtained by the technical solution in the related art, and the beneficial effects of the technical solution of the present application are described from the detection results. Refer to Figure 6 , Figure 6 In (a) in Figure 6 , it shows the image of the edge 15 position of the battery cell 20 obtained by adopting the technical solution of the present application, Figure 6 in (b) in Figure 6 it shows the image of the edge 15 position of the battery cell 20 obtained in the related art. It can be seen that Figure 6 the brightness of the edge 15 in (a) is about the same as the surrounding brightness, and the defect features near the edge 15 are obvious, without the occurrence of Figure 7 the bright line in (b) in Figure 7 . The appearance of the bright line in (b) may make it difficult to identify the defect features near the edge 15. Refer to Figure 7 In (c) in Figure 7 , it shows the defect image of the edge 15 of the battery cell 20 obtained by adopting the technical solution of the present application, Figure 7 in (d) in Figure 7 it shows the defect image of the edge 15 of the battery cell 20 obtained in the related art. For easy identification, Figure 8 the defects in Figure 8 are circled in the figure. It can be seen that, compared with Figure 8 in (d) in Figure 8 , the protruding or concave defect features in (c) in Figure 8In (e) of the figure, the defect of the scratch is more obvious. The above-listed are images regarding the brightness of the edge 15, the defects near the edge 15, and the scratches on the surface of the battery cell 20. In fact, for pits, bubbles, foreign objects, and breakages, the technical solution of the present application has a clearer recognition effect, which will not be listed one by one here.

[0065] By setting the reflecting member 40 to include the curved surface shell 4, it can make the light emitted from the partitioned light source 2 undergo multiple diffuse reflections on the diffuse reflection layer 7 on the inner wall of the curved surface shell 4, making the light incident on the battery cell 20 more uniform, being able to more clearly display the defects on the surface of the battery cell 20, and further improving the defect recognition rate and detection accuracy.

[0066] Refer to Figure 5 , in some embodiments, an annular mounting plate 3 is provided at the open end. The partitioned light source 2 includes a plurality of independently controlled first sub-light sources 21. The plurality of first sub-light sources 21 are arranged in an annular closed shape. The plurality of first sub-light sources 21 are sequentially and cyclically lit. When one of the first sub-light sources 21 is in the lit state, the remaining first sub-light sources 21 are in the dark state.

[0067] Certainly, the mounting plate 3 can be a plate-like structure for providing a mounting position for the partitioned light source 2. The mounting plate 3 can be mounted on the open end, specifically on the inner edge of the open end, arranged around the open end in a circle on the inner edge of the open end, that is, extending towards the center of the open end. An opening 33 is formed in the middle of the annular mounting plate 3 for allowing light to pass through. In this way, the partitioned light source 2 is mounted on the side of the mounting plate 3 facing the light-transmitting hole 42, so that the light emitted by the partitioned light source 2 can be directly incident on the diffuse reflection layer 7. Mounting the mounting plate 3 on the open end can utilize the entire curved surface shell 4 for diffuse reflection, and can reduce the volume of the curved surface shell 4.

[0068] Refer to Figure 5 , the first sub-light source 21 is in Figure 5It is represented by a small circle "○" in the figure. A plurality of first sub-light sources 21 are arranged around to form an annular partitioned light source 2. An inner circle of the annular plate forms an opening 33, and an outer circle of the annular plate is installed on an inner cavity wall of the curved surface shell 4, or the outer circle of the annular plate is installed at an open end of the curved surface shell 4. The independently controlled first sub-light sources 21 mean that a plurality of first sub-light sources 21 are separately controlled and can be independent of each other, that is, they are not simultaneously turned off or turned on like the conventional lamp beads we set. The annular shape here means that a plurality of first sub-light sources 21 form a circle with a hollow in the middle. The annular form can be various, including but not limited to square, circular, oval or racetrack-shaped. The plurality of first sub-light sources 21 are controlled by a sub-video strobing technology and are sequentially lit according to a control logic. It can be one lit at a time. The lit state means that the first sub-light source 21 is in the lit state, and the dark state means that the first sub-light source 21 is in the extinguished state. When one first sub-light source 21 is lit, the other first sub-light sources 21 are in the extinguished state, and then the next first sub-light source 21, and still the other first sub-light sources 21 are in the extinguished state. Setting the plurality of first sub-light sources 21 in an annular closed shape can correspond to each position of the battery cell 20 to be irradiated.

[0069] In this application, a photometric stereo method can be used to obtain an image of the surface of the battery cell 20. Specifically, the photometric stereo method is a specific implementation method in the sub-video strobing technology and is a method for obtaining three-dimensional information of an object by controlling the strobing frequency and time of a light source. The basic principle of the photometric stereo method is to utilize the change in the illumination intensity at different positions on the surface of an object at different time points, combine images from multiple viewpoints, and calculate the three-dimensional shape and surface characteristics of the object through a specific algorithm. Specifically, a plurality of first sub-light sources 21 in the partitioned light source 2 flash at a specific frequency. The frequency flashing means the lighting and extinguishing of the first sub-light source 21. At different flashing moments, the lighting conditions on the surface of the object will be different. In the images captured at different time points, the illumination intensity at the same position on the surface of the object will be different. By processing and analyzing these images at different time points, the three-dimensional shape of the object can be reconstructed using photometric information to obtain the image information of the battery cell 20.

[0070] By setting one of the first sub-light sources 21 in the lit state and the remaining first sub-light sources 21 in the dark state, and measuring using the photometric stereo method in the sub-video strobing technology, the image information of the surface of the battery cell 20 can be obtained. And by setting a plurality of first sub-light sources 21 to form an annular closed shape, the battery cell 20 can be irradiated from each position, and the obtained image information is more comprehensive and the detection accuracy is higher.

[0071] Refer to Figure 10 and Figure 11, in some embodiments, the mounting plate 3 includes a first mounting area 31 and a second mounting area 32 disposed on the outer periphery of the first mounting area 31. The second mounting area 32 is connected to the curved surface shell 4. The partitioned light source 2 includes a plurality of first sub-light sources 21 and a second sub-light source 22. The plurality of first sub-light sources 21 are disposed in the first mounting area 31 and form a first light source group in a ring-closed shape on the first mounting area 31. The second sub-light source 22 forms a second light source group in a ring-closed shape on the second mounting area 32, and the second light source group is disposed on the outer periphery of the first light source group.

[0072] In this embodiment, there are two ring-closed light sources. One is the first light source group in a ring-closed shape formed by arranging a plurality of first sub-light sources 21 on the first mounting area 31, which is disposed on the inner side. The other is the second light source group formed by enclosing the second sub-light source 22 on the second mounting area 32, and the second light source group is located on the outer periphery of the first light source group. This embodiment is particularly suitable for the detection of the window surface 13 of the battery cell 20. Specifically, with reference to Figure 14 , a blue film 14 is coated on the outer shell of the battery cell 20. Taking the battery cell 20 as a square battery cell as an example, the square battery cell has a plurality of sides. The window surface 13 refers to the surface where the center part of the side is not coated with the blue film 14 and the blue film 14 is coated around the side. We define the surface coated with the blue film 14 as the attached surface, and the surface without the blue film 14 coated in the middle of the attached surface as the exposed surface 131. The plurality of first sub-light sources 21 are sequentially lit through the time-sharing strobing logic, and the light after being reflected by the diffusing layer 7 is incident on the exposed surface 131. The light emitted by the second sub-light source 22 is incident on the blue film 14 after being reflected by the diffusing layer 7. By setting the light emitted by the second sub-light source 22 to be penetrable and able to pass through the blue film 14 and be incident on the attached surface, the detection of the window surface 13 can be realized, and since the light is uniform, the obtained image has a high recognition degree for defects.

[0073] Regarding the results obtained from the experiment, Figure 14 in (g1) and Figure 14 in (g2) represent the images obtained by detecting the window surface 13 of the battery cell 20 in the embodiment of the present application. Figure 14 in (h1) and Figure 14 in (h2) represent the images obtained by detecting the window surface 13 of the battery cell 20 in the related art. By comparing Figure 14 in (g1) and Figure 14 in (h1), it can be seen that for the scratches on the exposed surface 131, that is, the scratches in the square frame pointed by B1 in Figure 14 in (g1), the image of the embodiment of the present application is more obvious. Similarly, for the pit defects on the exposed surface 131 and the attached surface under the blue film 14, that is, the area framed by the square frame of B2 in Figure 14 in (g1), by comparing the imagesFigure 14 In (h1), it is almost invisible, while it can be clearly identified in the embodiments of the present application. For the edge 15 feature of the battery cell 20, that is Figure 14 As indicated by B3 in (g1), although the blue film 14 is coated, the edge 15 feature can be clearly identified in the embodiments of the present application. On the contrary, it is almost impossible to identify in the comparative example. Therefore, the recognition effect of the embodiments of the present application for detecting the window surface 13 of the battery cell 20 is far better than that of the related technical means.

[0074] By setting the partitioned light source 2 to include a plurality of first sub-light sources 21 and a second sub-light source 22, the plurality of first sub-light sources 21 are arranged in the first installation area 31 and enclose a first light source group in a ring-closed shape on the first installation area 31, and the second sub-light source 22 encloses a second light source group in a ring-closed shape on the second installation area 32, and the second light source group is arranged on the outer periphery of the first light source group. This embodiment is particularly suitable for detecting the window surface 13 of the battery cell 20.

[0075] Refer to Figure 11 , in some embodiments, the first installation area 31 includes a plurality of sub-areas that are connected end to end and have equal areas, and each sub-area is provided with a first sub-light source 21, and the first sub-light source 21 includes a plurality of lamp beads, and the number of lamp beads of the plurality of first sub-light sources 21 is the same.

[0076] The first installation area 31 includes a plurality of sub-areas, and the area of each sub-area is equal, or rather, the length of each sub-area is equal. Since each sub-area is not necessarily linear, the equal length here can be considered as the equal length of the center line of the sub-area. And only one first sub-light source 21 is arranged on each sub-area, and the number of lamp beads of each first sub-light source 21 is the same. It can also be set that the lamp beads are evenly distributed on the first sub-light source 21. With such a setting, the light intensity of each first sub-light source 21 is equal, and the light distribution within each sub-area is uniform. In this way, it is more conducive to forming an image of the battery cell 20 with uniform exposure, which is convenient for defect recognition.

[0077] By setting the first installation area 31 to include a plurality of sub-areas with equal areas, and the number of lamp beads of the first sub-light source 21 in each sub-area is the same, it is ensured that the light intensity of each sub-area is uniform and equal, which is beneficial to obtaining image information with uniform exposure and improving the accuracy of recognition.

[0078] Refer to Figure 14In some embodiments, the battery cell 20 includes an outer shell and a blue film 14, the outer shell includes a window surface 13, the window surface 13 includes an exposed surface 131 and an attachment surface arranged on the periphery of the exposed surface 131, the attachment surface is attached with the blue film 14, the light emitted by the first sub-light source 21 is incident on the exposed surface 131, and the light emitted by the second sub-light source 22 passes through the blue film 14 and is incident on the attachment surface.

[0079] This embodiment arranges two annular first sub-light sources 21 and second sub-light sources 22, which are particularly suitable for detecting the window surface 13 of the battery cell 20. However, the applicant needs to explain that the technical solution of the present application is not only suitable for detecting the window surface 13 of the battery cell 20, but also suitable for side detection of the outer shell that is not covered with the blue film 14, and can detect various defects on the surface of the battery cell 20.

[0080] By setting the light emitted by the first sub-light source 21 to be incident on the exposed surface 131 and the light emitted by the second sub-light source 22 to pass through the blue film 14 and be incident on the attached surface, this embodiment is particularly suitable for detecting the window surface 13 of the battery cell 20 .

[0081] In some embodiments, the light emitted by the first sub-light source 21 is visible light, and the light emitted by the second sub-light source 22 is infrared light.

[0082] Visible light is the part of the electromagnetic spectrum that can be perceived by the human eye. It is the wavelength of electromagnetic waves that can be perceived by the average person's eyes. It is generally believed that visible light is a light wave with a wavelength between 400nm and 760nm. The wavelength range of infrared light is usually defined as 0.76μm~1000μm, which is an electromagnetic wave between visible light and microwaves. For the detection of the window surface 13, the light emitted by the first sub-light source 21 is used to detect the exposed surface 131, that is, the part of the shell exposed to the blue film 14, and visible light can be used. For the attached surface, it is necessary to penetrate the blue film 14 to be incident on the shell, so infrared light with strong penetration is used. This embodiment is particularly suitable for the detection of the window surface 13 of the battery cell 20. The second sub-light source 22 is located on the periphery of the first sub-light source 21. The first sub-light source 21 corresponds to the exposed surface 131, and the light emitted by the second sub-light source 22 corresponds to the blue film 14. Of course, in other embodiments, the first sub-light source 21 and the second sub-light source 22 may both be infrared light or visible light, which can be selected according to the surface state of the workpiece that actually needs to be detected.

[0083] By setting the light emitted by the first sub-light source 21 to be visible light and the light emitted by the second sub-light source 22 to be visible light, it can be more suitable for detecting the window surface 13 of the battery cell 20 .

[0084] Reference Figure 3 and Figures 11 - 13, in some embodiments, the first light source group is distributed in a racetrack shape, a rectangular shape, an oval shape or a circular shape, and / or the second light source group is distributed in a racetrack shape, a rectangular shape, an oval shape or a circular shape.

[0085] Regarding the shapes of the first light source group and the second light source group, the present application does not make specific limitations, and they can be Figure 11 the racetrack shape shown in Figure 12 the circular shape shown in Figure 13 any one of the rectangular shape or the oval shape shown in

[0086] By reasonably setting the distribution patterns of the plurality of first sub-light sources 21 and the second sub-light sources 22, it is beneficial to irradiate the battery cells 20 from various positions, which is beneficial to obtaining the image information of the surface of the battery cells 20.

[0087] In some embodiments, the second sub-light source 22 and the plurality of first sub-light sources 21 are sequentially and cyclically lit. When one of the first sub-light sources 21 is in the lit state, the second sub-light source 22 and the remaining first sub-light sources 21 are in the dark state; when the second sub-light source 22 is in the lit state, each of the first sub-light sources 21 is in the dark state.

[0088] In this way, only one sub-light source is in the lit state each time. Here, the sub-light source refers to one of the first sub-light sources 21 or the second sub-light source 22. The following is a specific description of the lighting sequence of the first sub-light source 21 and the second sub-light source 22. In a specific embodiment, referring to Figure 10 , taking the number of sub-regions as four as an example, the first installation region 31 in the inner circle can be divided into four sub-regions A1, A2, A3, and A4. The second installation region 32 is located on the outer periphery of the first installation region 31 and is denoted as A5. With reference to Figure 11 , a first sub-light source 21 is provided in each sub-region, and a second sub-light source 22 is provided in the second installation region 32. The lighting sequence of each light source can be that first, the first sub-light source 21 in A1 is lit, and other light sources are in the extinguished state. Then A1 is extinguished and A2 is lit; then A2 is extinguished and A3 is lit; then A3 is extinguished and A4 is lit; then A4 is extinguished and A5 is lit; then A5 is extinguished and A1 is lit; then A1 is extinguished and A2 is lit. And so on in a cycle to obtain the image information of the surface of the battery cell 20, so as to identify defects according to the image information. Of course, those skilled in the art of the present application can understand that different timing control logics can also be set according to actual needs, and two sub-light sources can also be set to be lit simultaneously while the remaining sub-light sources are extinguished, or three sub-light sources can be set to be lit simultaneously while the remaining sub-light sources are extinguished.

[0089] By controlling the sequential cyclic lighting of the second sub-light source 22 and each first sub-light source 21, it is convenient to obtain the image information of the surface of the battery cell 20.

[0090] In some embodiments, the battery cell appearance detection device 200 further includes a controller for controlling the second sub-light source 22 and each first sub-light source 21 to be sequentially lit and extinguished according to a time-sharing stroboscopic logic.

[0091] The controller can be a control device or include a control chip with a logic program set therein, capable of sequentially lighting and extinguishing the first sub-light source 21 and the second sub-light source 22 according to the time-sharing stroboscopic logic, ensuring that only one sub-light source is in the lit state at a time. At the same time, the lit state or extinguished state of each sub-light source is in a preset order.

[0092] By setting the controller to sequentially light and extinguish multiple first sub-light sources 21 and the second sub-light source 22 according to the time-sharing stroboscopic logic, it is convenient to obtain the image information of the battery cell 20.

[0093] Refer to Figure 2 , in some embodiments, the battery cell appearance detection device 200 further includes a housing 230 and a mounting bracket 5 mounted on the housing 230. The mounting bracket 5 is used to mount the image acquisition member 220, and the image acquisition member 220 is movably mounted on the mounting bracket 5 and can adjust the position of the image acquisition member 220 on the mounting bracket 5 to facilitate obtaining image information. The mounting hole and the through hole 6 are arranged back to back and communicate with each other. The curved surface shell 4 is mounted on the mounting hole. Specifically, the open edge of the curved surface shell 4 is mounted on the through hole 6, the light-transmitting hole 42 and the through hole 6 are correspondingly arranged, and the image acquisition member 220 is correspondingly arranged with the through hole 6, so that the light emitted from the light-transmitting hole 42 can pass through the through hole 6 and be emitted to the image acquisition member 220, facilitating the image acquisition member 220 to obtain the image information of the battery cell 20.

[0094] Specifically, a connecting plate 41 can be provided at the outer edge of the open end of the curved surface shell 4. The connecting plate 41 extends in a direction away from the center of the open end. Through the connecting plate 41, the curved surface shell 4 can be mounted on the outer edge of the mounting hole, that is, fixed on the housing 230. Specifically, threaded holes can be provided at corresponding positions on the connecting plate 41 and the housing 230, and the connecting plate 41 is fixedly connected to the housing 230 through threaded fasteners. The through hole 6 is used for light to pass through, so that the light transmitted from the light-transmitting hole 42 can be received by the image acquisition member 220 through the through hole 6.

[0095] By arranging the curved surface shell 4 to be installed in the installation hole, with the opening 33 of the curved surface shell 4 facing away from the through hole 6, the light-transmitting hole 42 corresponding to the through hole 6, and the image acquisition member 220 being movably installed on the mounting bracket 5 and corresponding to the through hole 6, the housing 230 provides an installation position for the curved surface shell 4 and does not obstruct the propagation of light, facilitating the image acquisition member 220 to obtain the light reflected by the battery cell 20, and further obtaining the image information of the battery cell 20, which can conveniently identify the defects of the battery cell 20 subsequently.

[0096] Referring to Figure 16 , in some embodiments, the mounting bracket 5 includes a base plate 51, a first sliding plate 52, a second sliding plate 53, and a rotating plate 54. The base plate 51 is installed on the housing 230. The first sliding plate 52 is slidably installed on the base plate 51. The second sliding plate 53 is slidably installed on the first sliding plate 52. The sliding direction of the first sliding plate 52 is perpendicular to the sliding direction of the second sliding plate 53. The rotating plate 54 is installed on the second sliding plate 53 and can rotate relative to the second sliding plate 53. The image acquisition member 220 is installed on the rotating plate 54.

[0097] The base plate 51 can be a bottom plate. The base plate 51 is fixedly installed on the housing 230. A first sliding rail 511 is provided on the base plate 51. The first sliding plate 52 is slidably engaged with the first sliding rail 511. The first sliding plate 52 can slide on the first sliding rail 511. At the same time, some parts of the first sliding plate 52 facing away from the base plate 51 are provided with a second sliding rail 521. The second sliding plate 53 is slidably engaged with the second sliding rail 521. The second sliding plate 53 can slide on the second sliding rail 521, and the sliding direction of the first sliding plate 52 is perpendicular to the sliding direction of the second sliding plate 53. In this way, it is convenient to adjust the position of the image acquisition member 220 in the horizontal plane. At the same time, considering the need for the acquisition angle of the image acquisition member 220, the image acquisition member 220 can be not directly installed on the second sliding plate 53, but a rotating plate 54 is provided. The rotating plate 54 is arranged on the second sliding plate 53, and the image acquisition member 220 is installed on the rotating plate 54. The rotating plate 54 can rotate horizontally or vertically. In this way, the angle of the image acquisition member 220 can be adjusted.

[0098] By arranging the first sliding plate 52 and the second sliding plate 53 with perpendicular sliding directions, the position of the image acquisition member 220 in the horizontal plane can be adjusted. By arranging the rotating plate 54, the angle of the image acquisition member 220 can be adjusted.

[0099] According to some embodiments of the present application, the present application provides a battery cell appearance inspection device 200, including a partitioned light source 2, a curved shell 4 and an image acquisition component 220, the curved shell 4 encloses a cavity with an opening, a light-transmitting hole 42 connected to the cavity is arranged on the curved shell 4, a diffuse reflection layer 7 is arranged on the inner wall surface of the curved shell 4, a mounting plate 3 is arranged on the curved shell 4, the curved shell 4 is a dome structure, the mounting plate 3 is arranged at the edge of the opening, and extends toward the center of the opening. The mounting plate 3 is surrounded by an opening 33 connected to the cavity. A partitioned light source 2 is arranged on the side of the mounting plate 3 facing the light-transmitting hole 42. The partitioned light source 2 is arranged along the extending direction of the mounting plate 3. The light emitted by the partitioned light source 2 is incident on the diffuse reflection layer 7, and is diffusely reflected on the diffuse reflection layer 7 and then emitted to the battery cell 20 through the opening 33; the image acquisition component 220 is located on the side of the curved shell 4 away from the diffuse reflection layer 7. The image acquisition component 220 is arranged corresponding to the light-transmitting hole 42, and the image acquisition component 220 is used to obtain the reflected light of the battery cell 20. In a specific embodiment, the mounting plate 3 includes a first mounting area 31 and a second mounting area 32 arranged on the periphery of the first mounting area 31, the second mounting area 32 is connected to the curved shell 4, the partitioned light source 2 includes a plurality of first sub-light sources 21 and a second sub-light source 22, the plurality of first sub-light sources 21 are arranged in the first mounting area 31 and are arranged on the first mounting area 31 to form a first light source group in a circular closed shape, the second sub-light sources 22 are arranged on the second mounting area 32 to form a second light source group in a circular closed shape, the second light source group is arranged on the periphery of the first light source group, the light emitted by the first sub-light source 21 is visible light, and the light emitted by the second sub-light source 22 is infrared light, and the controller uses time-sharing strobe logic to light up and extinguish the plurality of first sub-light sources 21 and the second sub-light source 22 in sequence. The battery cell 20 includes a shell and a blue film 14, the shell includes a window surface 13, the window surface 13 includes an exposed surface 131 and an attached surface arranged on the periphery of the exposed surface 131, the attached surface is attached with a blue film 14, the light emitted by the first sub-light source 21 is incident on the exposed surface 131, and the light emitted by the second sub-light source 22 passes through the blue film 14 and is incident on the attached surface. In another specific embodiment, the battery cell appearance inspection device 200 also includes a shell 230 and a mounting frame 5 installed on the shell 230, the mounting frame 5 includes a substrate 51, a first slide plate 52, a second slide plate 53 and a rotating plate 54, the substrate 51 is installed on the shell 230, the first slide plate 52 is slidably installed on the substrate 51, the second slide plate 53 is slidably installed on the first slide plate 52, the sliding direction of the first slide plate 52 is perpendicular to the sliding direction of the second slide plate 53, the rotating plate 54 is installed on the second slide plate 53 and can rotate relative to the second slide plate 53, and the image acquisition component 220 is installed on the rotating plate 54. The present application has the advantage of high defect recognition accuracy.

[0100] Reference Figure 17 , Figure 17This is a schematic flowchart of the method for detecting the appearance of a battery cell in the first embodiment of the present application. The present application provides a method for detecting the appearance of a battery cell, which is applied to the above-mentioned battery cell appearance detection device 200. The method for detecting the appearance of a battery cell includes the following steps: S100, control multiple first sub-light sources 21 of the partitioned light source 2 to sequentially cycle and light up according to the time-sharing stroboscopic logic; when one of the first sub-light sources 21 is in the lit state, the remaining first sub-light sources 21 are in the dark state, and the light emitted by the first sub-light source 21 is incident on the diffuse reflection layer 7 of the curved surface shell 4.

[0101] Before the detection starts, arrange the battery cell 20 to be detected, the reflector 40, the image acquisition member 220, and the partitioned light source 2 so that the image acquisition member 220 and the battery cell 20 are respectively located on both sides of the reflector 40. The light emitted by the partitioned light source 2 is emitted towards the diffuse reflection layer 7 of the reflector 40, and the light reflected by the diffuse reflection layer 7 is incident on the battery cell 20. The image acquisition member 220 can collect the reflected light of the battery cell 20 through the light-transmitting hole 42. In this embodiment, it is described that the partitioned light source 2 has a closed annular shape. The partitioned light source 2 includes multiple first sub-light sources 21, and the multiple first sub-light sources 21 enclose a closed ring. The multiple first sub-light sources 21 are independently controlled and sequentially cycle and light up. When one of the first sub-light sources 21 is in the lit state, the remaining first sub-light sources 21 are in the dark state. Specifically, the first sub-light source 21 can be arranged on the mounting plate 3.

[0102] Specifically, the first sub-light source 21 is Figure 5 represented by a small circle "○" in the figure, and multiple first sub-light sources 21 surround to form the annular partitioned light source 2. An opening 33 is formed in the inner circle of the mounting plate 3, and the outer circle of the mounting plate 3 is mounted on the inner cavity wall of the curved surface shell 4, or the outer circle of the mounting plate 3 is mounted at the open end of the curved surface shell 4. The independently controlled first sub-light source 21 means that the multiple first sub-light sources 21 are respectively and independently controlled and can be independent of each other, that is, they are not like the conventional lamp beads that are extinguished or lit simultaneously. The annular shape here means that the multiple first sub-light sources 21 enclose a circle with a hollow in the middle. The annular form can have various types, including but not limited to square, circular, oval, or runway-shaped. The multiple first sub-light sources 21 are controlled by the time-sharing stroboscopic technology and are sequentially lit according to the control logic. It can be that one is lit each time. The lit state means that the first sub-light source 21 is in the lit state, and the dark state means that the first sub-light source 21 is in the extinguished state. When one first sub-light source 21 is lit, the other first sub-light sources 21 are in the extinguished state. Setting the multiple first sub-light sources 21 in a closed annular shape can correspond to irradiating each position of the battery cell 20.

[0103] S200, control the image acquisition member 220 to obtain the image information on the surface of the battery cell 20.

[0104] The image acquisition component 220 can be a camera or a video camera, and can obtain image information by taking pictures. Specifically, the image acquisition component 220 is located on the side of the reflector 40 away from the diffuse reflection layer 7. The image acquisition component 220 is arranged corresponding to the light transmission hole 42. The light reflected from the battery cell 20 can enter the image acquisition component 220 through the light transmission hole 42. The image acquisition component 220 is used to acquire the reflected light of the battery cell 20 to obtain the image information of the surface of the battery cell 20, and the image information can be used to analyze and identify the defects on the surface of the battery cell 20.

[0105] In the above embodiments of the present application, by controlling the multiple first sub-light sources 21 of the partitioned light source 2 to be sequentially cyclically lit according to the time-sharing stroboscopic logic, and the light emitted by the first sub-light source 21 enters the diffuse reflection layer 7 of the curved surface shell 4, and controlling the image acquisition component 220 to acquire the image information of the surface of the battery cell 20, the light after diffuse reflection can be made to enter the battery cell 20, so that the light incident on the battery cell 20 is uniform, with the ability to resist high reflectivity, reducing the risk that bright lines appear due to overexposure, resulting in unclear defect imaging. It has better imaging for defects of different materials and types, can more clearly display the defects on the surface of the battery cell 20, and has the advantages of high defect recognition and detection accuracy.

[0106] Refer to Figure 17 , Figure 17 This is a schematic flowchart of the method for detecting the appearance of the battery cell in the first embodiment of the present application. The partitioned light source 2 further includes a second sub-light source 22. The multiple first sub-light sources 21 enclose a first light source group in a circular closed shape. The second sub-light source 22 encloses a second light source group in a circular closed shape. The second light source group is arranged on the outer periphery of the first light source group. The battery cell 20 includes a housing and a blue film 14. The housing includes a window surface 13. The window surface 13 includes an exposed surface 131 and an attachment surface arranged on the outer periphery of the exposed surface 131. The blue film 14 is attached to the attachment surface. The step of controlling the multiple first sub-light sources 21 of the partitioned light source 2 to be sequentially cyclically lit according to the time-sharing stroboscopic logic includes: S101, controlling the second sub-light source 22 and the multiple first sub-light sources 21 to be lit and extinguished according to the time-sharing stroboscopic logic; when one of the first sub-light sources 21 is in the lit state, the second sub-light source 22 and the remaining first sub-light sources 21 are in the dark state; when the second sub-light source 22 is in the lit state, each of the first sub-light sources 21 is in the dark state.

[0107] In this embodiment, there are two annular closed light sources. One is a first light source group formed by arranging a plurality of first sub-light sources 21 on a first installation area 31 in an annular closed shape, which is arranged inside. The other is a second light source group formed by surrounding the second sub-light sources 22 on a second installation area 32. The second light source group is located on the outer periphery of the first light source group. This embodiment is particularly applicable to the detection of the window surface 13 of the battery cell 20. Specifically, with reference to Figure 14 , a blue film 14 is coated on the outer shell of the battery cell 20. Taking the battery cell 20 as a square battery cell as an example, the square battery cell has multiple sides. The window surface 13 refers to the surface where the central part of the side is not coated with the blue film 14 and the blue film 14 is coated around the side. We define the surface coated with the blue film 14 as the attached surface, and the surface without the blue film 14 coated in the middle of the attached surface as the exposed surface 131. The multiple first sub-light sources 21 are sequentially lit through the time-sharing strobing logic. The light after being reflected by the diffuse reflection layer 7 is incident on the exposed surface 131. The light emitted by the second sub-light sources 22 is incident on the blue film 14 after being reflected by the diffuse reflection layer 7. By setting the light emitted by the second sub-light sources 22 to be penetrable, it can pass through the blue film 14 and be incident on the attached surface.

[0108] Specifically, next, a specific description will be made on the lighting sequence of the first sub-light sources 21 and the second sub-light sources 22. In a specific embodiment, with reference to Figure 10 , taking the number of sub-regions as four as an example, the inner first installation area 31 can be divided into four sub-regions A1, A2, A3, and A4. The second installation area 32 is located on the outer periphery of the first installation area 31 and is denoted as A5. With reference to Figure 11 , the first sub-light sources 21 are arranged in each sub-region, and the second sub-light sources 22 are arranged in the second installation area 32. The lighting sequence of each light source can be that first, the first sub-light source 21 in A1 is lit, and other light sources are in the extinguished state. Then A1 is extinguished and A2 is lit; then A2 is extinguished and A3 is lit; then A3 is extinguished and A4 is lit; then A4 is extinguished and A5 is lit; then A5 is extinguished and A1 is lit; then A1 is extinguished and A2 is lit. This cycle is repeated to obtain the image information of the surface of the battery cell 20 for defect recognition based on the image information. Of course, those skilled in the art of this application can understand that different timing control logics can also be set according to actual needs.

[0109] The above embodiment of the present application is particularly applicable to the detection of the window surface 13 of the battery cell 20, and due to the uniform light, the obtained image has a high recognition degree for defects.

[0110] The above are only alternative embodiments of the present application, and do not limit the protection scope of the present application accordingly. Any equivalent structural transformation made by using the content of the specification and drawings of the present application under the technical concept of the present application, or any direct / indirect application in other related technical fields, is included in the protection scope of the present application.

Claims

1. An appearance detection device for a battery cell, characterized in that, include: A reflector, wherein the reflector is provided with a light-transmitting hole, and a diffuse reflection layer is provided on one side of the reflector; A partitioned light source, wherein the partitioned light sources are distributed in a ring shape and are arranged toward the diffuse reflection layer; the partitioned light source comprises a plurality of independently controlled first sub-light sources, wherein the plurality of first sub-light sources are arranged in a ring-shaped closed shape, and the plurality of first sub-light sources are sequentially and cyclically lit; wherein when one first sub-light source is in a bright state, the other first sub-light sources are in a dark state; An image acquisition component is arranged on a side of the reflector away from the partitioned light source, and the image acquisition component is arranged toward the light transmission hole.

2. The appearance detection device for battery cells according to claim 1, characterized in that, The reflector comprises a curved shell, the curved shell encloses a cavity with an opening, and the diffuse reflection layer is arranged on the inner wall surface of the cavity.

3. The battery cell appearance detection device according to claim 2, wherein The opening is provided with an annular mounting plate, and a plurality of the first sub-light sources are arranged on the mounting plate.

4. The battery cell appearance detection device according to claim 3, wherein, The mounting plate includes a first mounting area and a second mounting area arranged on the periphery of the first mounting area, the second mounting area is connected to the curved shell, the partitioned light source also includes a second sub-light source, a plurality of the first sub-light sources are arranged in the first mounting area and are arranged on the first mounting area to form a first light source group in a ring-shaped closed shape, the second sub-light sources are arranged on the second mounting area to form a second light source group in a ring-shaped closed shape, and the second light source group is arranged on the periphery of the first light source group.

5. The battery cell appearance detection device according to claim 4, wherein, The first light source group is distributed in a racetrack shape, a rectangle, an ellipse or a circle, and / or the second light source group is distributed in a racetrack shape, a rectangle, an ellipse or a circle.

6. The battery cell appearance detection device according to claim 4, characterized in that The first installation area includes a plurality of sub-areas connected end to end and having equal areas, each of the sub-areas is provided with a first sub-light source, the first sub-light source includes a plurality of lamp beads, and the number of the lamp beads of the plurality of first sub-light sources is the same.

7. The battery cell appearance detection device according to claim 4, characterized in that The light emitted by the first sub-light source is visible light, and the light emitted by the second sub-light source is infrared light.

8. The battery cell appearance detection device according to claim 7, characterized in that, The battery cell includes an outer shell and a blue film, the outer shell includes a window surface, the window surface includes an exposed surface and an attachment surface arranged on the periphery of the exposed surface, the blue film is attached to the attachment surface, the light emitted by the first sub-light source is incident on the exposed surface, and the light emitted by the second sub-light source passes through the blue film and is incident on the attachment surface.

9. The battery cell appearance detection device according to claim 4, wherein The second sub-light source and the first sub-light sources are sequentially and cyclically lit; wherein, When one of the first sub-light sources is in a bright state, the second sub-light source and the remaining first sub-light sources are in a dark state; or, When the second sub-light sources are in a bright state, each of the first sub-light sources is in a dark state.

10. The battery cell appearance detection device according to claim 9, characterized in that, The battery cell appearance inspection device further includes a controller, which is used to control the second sub-light source and a plurality of the first sub-light sources to light up and extinguish in sequence according to a time-sharing strobe logic.

11. The battery cell appearance detection device according to any one of claims 2 to 8, characterized in that, The battery cell appearance inspection device also includes a shell and a mounting frame installed on the shell, the shell is provided with a mounting hole and a through hole, the curved shell is installed in the mounting hole, the light-transmitting hole is arranged corresponding to the through hole, and the image acquisition component is movably installed on the mounting frame and arranged corresponding to the through hole.

12. The battery cell appearance detection device according to claim 11, wherein, The mounting bracket includes a base plate, a first sliding plate, a second sliding plate and a rotating plate. The base plate is mounted on the housing. The first sliding plate is slidably mounted on the base plate. The second sliding plate is slidably mounted on the first sliding plate. The sliding direction of the first sliding plate is perpendicular to the sliding direction of the second sliding plate. The rotating plate is mounted on the second sliding plate and can rotate relative to the second sliding plate. The image acquisition member is mounted on the rotating plate.

13. A method for detecting the appearance of a battery cell, applied to the battery cell appearance detection device according to any one of claims 1 to 12, characterized in that, The method for detecting the appearance of a single battery cell includes the following steps: Controlling a plurality of first sub-light sources of the partitioned light source to be sequentially and circularly lit according to a time-sharing stroboscopic logic; when one of the first sub-light sources is in the lit state, the remaining first sub-light sources are in the dark state, and the light emitted by the first sub-light source is incident on the diffuse reflection layer of the curved shell; Controlling the image acquisition member to acquire image information on the surface of the single battery cell.

14. The method for detecting the appearance of a battery cell according to claim 13, wherein, The partitioned light source further includes a second sub-light source. A plurality of the first sub-light sources enclose a first light source group in an annular closed shape. The second sub-light source encloses a second light source group in an annular closed shape. The second light source group is arranged on the outer periphery of the first light source group. The single battery cell includes a housing and a blue film. The housing includes a window surface. The window surface includes an exposed surface and an attaching surface provided on the outer periphery of the exposed surface. The blue film is attached to the attaching surface. The step of controlling a plurality of first sub-light sources of the partitioned light source to be sequentially and circularly lit according to a time-sharing stroboscopic logic includes: Controlling the second sub-light source and a plurality of first sub-light sources to be lit and extinguished according to a time-sharing stroboscopic logic; wherein, when one of the first sub-light sources is in the lit state, the second sub-light source and the remaining first sub-light sources are in the dark state; or, when the second sub-light source is in the lit state, all the first sub-light sources are in the dark state.

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