An image acquisition device and a photovoltaic module laser welding system

Abstract

The application provides an image acquisition device and a photovoltaic module laser welding system. The image acquisition device comprises a light source module and an imaging module. The imaging module allows light beams in a preset wavelength range to pass through. The light source module emits light beams with wavelengths in the preset wavelength range, thereby excluding interference of other light beams outside the preset wavelength range on imaging. The light source module comprises first light sources arranged on both sides of a cell sheet along a first direction and second light sources arranged on both sides of the cell sheet along a second direction. The second light sources, the first light sources and the imaging module are sequentially arranged above the cell sheet from bottom to top. The light beams emitted by the first light sources and the second light sources are both obliquely irradiated on the cell sheet from top to bottom at a preset angle. The interference of a silica gel plate on imaging of the cell sheet can be effectively excluded. Clear, reliable and accurate images of the cell sheet are obtained. The laser welding unit can accurately emit light according to position coordinate information of a to-be-welded point, and good welding effect is obtained.

Description

Technical Field

[0001] This application belongs to the field of photovoltaic module manufacturing technology, specifically, it relates to an image acquisition device and a photovoltaic module laser welding system. Background Technology

[0002] In the laser welding process of photovoltaic modules, it is essential to ensure that the solder ribbons remain in close contact with the welding contact points of the solar cells. This guarantees the absence of gaps or voids between the solder ribbons and the welding contact points after welding, ensuring full conductivity in all solar cells. To address this issue, after arranging the solder ribbons on the solar cells, a flexible, semi-transparent silicone sheet (typically 2-3 mm thick) is placed over the entire solar panel. A vacuum is then created between the silicone sheet and the solar panel, ensuring a tight bond between them. A uniform downward pressure is applied to the entire solar panel, ensuring that all solder ribbons on the panel are in close contact with their corresponding welding contact points on the solar cells. Subsequently, an image acquisition device photographs the solar cells to obtain the location information of the intersection of the solder ribbons and welding contact points (the welding points). The laser then performs precise laser beam welding based on this location information.

[0003] Due to factors such as the material, thickness, and optical properties of the silicone plate, it is difficult to obtain clear, stable, and accurate images using existing image acquisition devices, which in turn makes it impossible to obtain accurate location information of the points to be welded, resulting in poor welding effects. Utility Model Content

[0004] In view of this, this application provides an image acquisition device and a photovoltaic module laser welding system, which can eliminate the interference of silicone plate and obtain accurate position information of the point to be welded, thereby achieving excellent welding results.

[0005] An image acquisition device includes a light source module and an imaging module. The light source module emits a light beam that illuminates a battery cell covered with a silicone plate. The imaging module acquires an image of the illuminated battery cell. The imaging module allows light beams within a preset wavelength range to pass through. The wavelength of the light beam emitted by the light source module is within the preset wavelength range.

[0006] The light source module includes a first light source arranged on both sides of the battery cell along a first direction and a second light source arranged on both sides of the battery cell along a second direction. The first direction and the second direction are perpendicular to each other in the same plane, and the first direction is the extension direction of the solder strip.

[0007] A second light source, a first light source, and an imaging module are arranged sequentially above the battery cell from bottom to top. The beams emitted by the first and second light sources are both at a preset angle, illuminating the battery cell obliquely from top to bottom.

[0008] Preferably, the imaging module includes a camera, a lens, and a filter. One end of the lens is connected to the camera, and the filter is installed at the other end of the lens. The filter allows light beams within a preset wavelength range to pass through the lens and then the camera in sequence.

[0009] Preferably, both the first and second light sources are strip-shaped light sources, and their lengths are greater than the lengths of the corresponding sides of the battery cell; and / or, the light beam emitted by the light source module is infrared light with a wavelength of 850 μm, and the preset wavelength range is 810–870 μm.

[0010] Preferably, the preset angle is 30 to 60°.

[0011] Preferably, in the height direction, the vertical distance between the second light source and the battery cell is 150-250 mm.

[0012] Preferably, the vertical distance between the first light source and the second light source in the height direction is 50-100 mm.

[0013] Preferably, in the height direction, the vertical distance between the filter and the battery cell is 300-400 mm.

[0014] Preferably, the distance between the projection of the imaging module's field of view center onto the battery cell and the center of the battery cell is -100 to 100 mm.

[0015] Preferably, the distance between the projection of each first light source and each second light source onto the plane of the solar cell and the center of the solar cell is 100-150 mm.

[0016] This application also provides a photovoltaic module laser welding system, including the aforementioned image acquisition device, as well as an arrangement unit disposed at the front end of the image acquisition device and a laser welding unit disposed at the rear end of the image acquisition device along the photovoltaic module conveying direction;

[0017] The arrangement unit is used to press the silicone plate onto the entire battery panel, and to press the welding strip onto the welding contact point of the battery cell through the silicone plate;

[0018] After receiving the position information of the battery cell from the image acquisition device, the laser welding unit emits a laser beam that passes through the silicone plate to weld the welding strip to the welding contact point.

[0019] The beneficial effects of this application are as follows: the imaging module only allows light beams within a preset wavelength range to pass through, and the wavelength of the light beam emitted by the light source module is within the preset wavelength range, enabling the light beam emitted by the light source module to enter the imaging module, while light beams outside the preset wavelength range cannot enter the imaging module, thereby eliminating interference from other light beams outside the preset wavelength range on the imaging; in addition, a first light source is set on both sides of the battery cell along the first direction, and a second light source is set on both sides of the battery cell along the second direction, with the second light source located above the battery cell in the height direction, the first light source located above the second light source, and the imaging module located above the first light source. The light beams emitted by the first and second light sources are both obliquely illuminating the battery cell from top to bottom at a preset angle, which can effectively eliminate the interference of the silicone plate on the imaging of the battery cell, obtain a clear, reliable, and accurate battery cell image, thereby obtaining accurate position coordinate information of the point to be welded, enabling the laser welding unit to accurately emit light according to the position coordinate information of the point to be welded, and obtain a good welding effect. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0022] Figure 1 This is a schematic diagram of a structure where a silicone plate presses the solder strip onto the solder contact point of the battery cell.

[0023] Figure 2 A schematic diagram of the image acquisition device provided in this application;

[0024] Figure 3 Another structural schematic diagram of the image acquisition device provided in this application;

[0025] Figure 4 Another structural schematic diagram of the image acquisition device provided in this application;

[0026] Figure 5 This is a schematic diagram of the imaging module.

[0027] Figure 6 This is a schematic diagram of the structure of the photovoltaic module laser welding system provided in this application.

[0028] In the diagram: 1-Silicone sheet; 11-Warped surface; 2-Battery cell; 3-Welding strip; 4-Uncontacted area; 5-Light source module; 51-First light source; 52-Second light source; 6-Imaging module; 61-Camera; 62-Lens; 63-Filter; 100-Image acquisition device; 200-Layout unit; 300-Laser welding unit. Detailed Implementation

[0029] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0030] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] To prevent gaps and holes between the solder ribbon and the solar cell during laser welding, after the solder ribbons are arranged on each cell of the entire solar panel (hereinafter referred to as the panel), a semi-transparent flexible silicone sheet (hereinafter referred to as the silicone sheet) is placed over the panel. The silicone sheet is typically 2-3 mm thick and its dimensions are the same as those of the panel. A vacuum is then created in the area between the silicone sheet and the panel, pressing the silicone sheet firmly against the panel and thus pressing the solder ribbons tightly against the welding contact points, ensuring a close fit between the solder ribbons and the welding contact points.

[0032] Before laser welding, an image acquisition device is needed to take pictures of the battery cells to obtain the position coordinates of the intersection of the welding strip and the welding contact point (hereinafter referred to as the welding point) within the field of view of the image acquisition device, so as to position and guide the laser to perform precise laser welding.

[0033] Due to the semi-transparent nature of the silicone sheet, it appears visually as a white, semi-transparent, and blurry image. When the silicone sheet covers the solar cell, if it appears white and semi-transparent, the image of the solar cell obtained using existing image acquisition devices will appear washed out and have reduced contrast, decreasing from 200-220 (images without the silicone sheet) to 30-50. If it appears blurry, it will make it impossible to clearly identify feature locations based on the obtained image of the solar cell, and the edge transition pixels will increase from 2-4 pixels (images without the silicone sheet) to 5-10 pixels.

[0034] Additionally, refer toFigure 1 When a vacuum is drawn in the area between the silicone plate 1 and the battery panel, due to the thickness of the solder strip 3 laid on the battery cell 2 and the flexibility of the silicone plate 1, the silicone plate 1 on both sides of the solder strip 3 in the length direction of the solder strip will have a warped surface 11, which will produce a reflection at a fixed angle. In addition, there may be an uncontacted area 4 between the silicone plate 1 on both sides of the solder strip 3 in the length direction of the solder strip and the solder strip 3. The uncontacted area 4 refers to pores, bubbles, etc. that are not completely vacuumed, which will affect the imaging effect.

[0035] Therefore, this application provides an image acquisition device, with reference to Figures 2-5 It includes a light source module 5 and an imaging module 6. The light beam emitted by the light source module 5 illuminates the battery cell 2 covered with a silicone plate. The imaging module 6 acquires an image of the illuminated battery cell 2. The imaging module 6 allows light beams within a preset wavelength range to pass through. The wavelength of the light beam emitted by the light source module 5 is within the preset wavelength range.

[0036] The light source module 5 includes a first light source 51 arranged along the first direction on both sides of the battery cell 2 and a second light source 52 arranged along the second direction on both sides of the battery cell 2. The first direction and the second direction are perpendicular to each other in the same plane. The first direction is the extension direction of the solder strip (i.e., the length direction of the solder strip).

[0037] A second light source 52, a first light source 51, and an imaging module 6 are arranged sequentially above the battery cell 2 from bottom to top. The beams emitted by the first light source 51 and the second light source 52 are both at a preset angle and irradiate the battery cell 2 from top to bottom.

[0038] The imaging module 6 in this embodiment only allows light beams within a preset wavelength range to pass through, and the wavelength of the light beam emitted by the light source module 5 is within the preset wavelength range, thereby eliminating interference from other light beams outside the preset wavelength range besides the light beam emitted by the light source module 5.

[0039] During image acquisition, in addition to the light beam emitted by the light source module 5, there are other complex ambient lights (hereinafter referred to as stray light), such as sunlight, lamplight, and light generated by other light sources on the equipment. If stray light is not filtered out, it will enter the imaging module 6 and affect the image quality. For example, it may cause the chip inside the camera to become light-sensitive, resulting in a washed-out image. In addition, the irregular changes in stray light can cause the imaging effect to be unstable. For example, it may be affected by sunlight, resulting in high image brightness during the day and low image brightness at night, thereby increasing the difficulty of image processing algorithms and the risk of false detection.

[0040] Light sources are positioned on all four sides of the battery cell 2 to be imaged, uniformly illuminating the battery cell 2 from all four sides to ensure uniform overall brightness. A second light source 52, positioned along the second direction, is located above the battery cell 2, while a first light source 51, positioned along the first direction, is located above the second light source 52. The beams emitted by both light sources 51 and 52 are angled downwards at a preset angle, illuminating the battery cell 2. This allows the first light source 51 to illuminate the battery cell 2 from a higher height, resulting in more uniform illumination and minimizing the influence of reflections from the warped surface 11. The second light source 52, compared to the first light source 52, illuminates the battery cell 2 from a lower height, thus minimizing the influence of the uncontacted area 4.

[0041] In this embodiment, both the first light source 51 and the second light source 52 are strip-shaped light sources, and their length is greater than the side length of the corresponding battery cell, so as to ensure that the entire battery cell can be illuminated uniformly.

[0042] The image acquisition device described in this application embodiment can eliminate the interference of the silicone plate and obtain clear, accurate and stable imaging, thereby obtaining accurate position coordinate information of the point to be welded, so as to make the laser welding position precise.

[0043] In a preferred embodiment, refer to Figure 5 The imaging module 6 includes a camera 61, a lens 62, and a filter 63. One end of the lens 62 is connected to the camera 61, and the filter 63 is installed at the other end of the lens 62. The filter 63 allows light beams within a preset wavelength range to pass through the lens 62 and the camera 61 in sequence.

[0044] By setting a filter 63 at the end of the lens 62 away from the camera 61, light beams outside the preset wavelength range cannot enter the lens 62 and the camera 61, thus eliminating the interference of light beams outside the preset wavelength range on the imaging of the camera 61.

[0045] In one specific embodiment, the light beam emitted by the light source module 5 is infrared light with a wavelength of 850 μm, and the preset wavelength range is 810 to 870 μm.

[0046] The light beams emitted by the first light source 51 and the second light source 52 are both infrared light with a wavelength of 850μm. Compared with visible light, infrared light has a longer wavelength and stronger penetrability. When it shines on the silicone plate, the penetration effect is good. Based on this, the whitening and blurring in the image obtained by the imaging module 6 are significantly improved, and the image is clear.

[0047] In order to allow infrared light with a wavelength of 850μm to enter the lens 62 and camera 61 and to eliminate interference from other light on imaging, this embodiment can use a bandpass filter so that light beams with a preset wavelength range of 810 to 870μm can pass through the filter 63, thereby allowing the light beams emitted by the first light source 51 and the second light source 52 to enter the lens 62 and camera 61.

[0048] The above design avoids the appearance of washed-out and blurry images, and prevents interference from stray light such as visible light, resulting in clear, stable, and accurate images.

[0049] In a further specific implementation, the preset angle is 30 to 60°.

[0050] The preset angle in this embodiment is: Figure 3 and Figure 4 The θ shown in the figure is 30 to 60°, which allows the first light source 51 and the second light source 52 to work together to illuminate the entire area of ​​the battery cell they enclose.

[0051] In a further specific embodiment, in the height direction, the vertical distance between the second light source 52 and the battery cell 2 is 150-250 mm, the vertical distance between the first light source 51 and the second light source 52 is 50-100 mm, and the vertical distance between the filter 63 and the battery cell 2 is 300-400 mm (i.e., the vertical distance between the end of the imaging module 6 closest to the battery cell 2 and the battery cell 2 is 300-400 mm). Furthermore, the distance between the projection of each first light source 51 and each second light source 52 onto the plane of the battery cell and the center of the battery cell 2 is 100-150 mm.

[0052] Through the above design, the image obtained can be minimized from the influence of the warped surface 11 and the uncontacted area 4, resulting in a good imaging effect.

[0053] In a further specific embodiment, the distance between the projection of the field of view center of the imaging module 6 onto the battery cell 2 and the center of the battery cell 2 is -100 to 100 mm. Preferably, the projection of the field of view center of the imaging module 6 onto the battery cell 2 coincides with the center of the battery cell 2. This minimizes the distortion effect of the lens 62 on the camera 61, resulting in better imaging. The better the imaging effect, the more accurate the position coordinates of the point to be welded will be.

[0054] Another embodiment of this application provides a photovoltaic module laser welding system, see reference. Figure 6The image acquisition device 100 mentioned above, as well as the arrangement unit 200 disposed at the front end of the image acquisition device 100 and the laser welding unit 300 disposed at the rear end of the image acquisition device 100 along the photovoltaic module conveying direction.

[0055] The arrangement unit 200 is used to press the silicone plate onto the entire battery panel, and press the welding strip onto the welding contact point of the battery cell through the silicone plate;

[0056] After receiving the position information of the battery cell obtained by the image acquisition device 100, the laser welding unit 300 emits a laser beam that passes through the silicone plate to weld the welding strip to the welding contact point.

[0057] The location information of the solar cell includes the coordinates of the points to be welded.

[0058] After the solder ribbons are arranged at the corresponding positions of each cell on the entire solar panel, they are conveyed to the arrangement unit 200. The arrangement unit 200 presses the silicone plate onto the entire solar panel so that the solder ribbons are pressed onto the solder contact points of the cells.

[0059] The specific structure of the arrangement unit 200 is existing technology. For example, the arrangement unit 200 may include a mechanical handling mechanism and a vacuuming mechanism. The mechanical handling mechanism transports the silicone plate to the top of the entire solar panel, and then places the silicone plate on the solar panel. Subsequently, the vacuuming mechanism is activated to vacuum the area between the silicone plate and the solar panel, pressing the silicone plate firmly onto the solar panel. This allows the silicone plate to press each solder strip onto the corresponding solder contact point of the solar cell.

[0060] After pressing each solder strip onto the corresponding solder contact point of the battery cell using a silicone plate, an image acquisition device is used to acquire images of each battery cell in the battery panel to obtain the position coordinate information of the solder point corresponding to each battery cell.

[0061] The obtained position coordinate information of the welding point corresponding to each battery cell is uploaded to the control system (such as PLC). The control system transmits the position coordinate information of the welding point corresponding to each battery cell to the laser welding unit 300. The laser welding unit 300 emits a laser beam to the corresponding welding point according to the obtained information, and welds the welding strip and the welding contact point together through the silicone plate.

[0062] The specific structure of the laser welding unit 300 is existing technology and will not be described in further detail.

[0063] The image acquisition device described in this application embodiment can effectively eliminate the interference of the white semi-transparent properties of the silicone plate on imaging, ensuring that the image effect is not washed out and the edge black-and-white contrast is around 200, which is a significant improvement compared to existing image acquisition devices. Simultaneously, it can effectively eliminate the interference of the silicone plate's blurry features on imaging, ensuring that the image effect is not blurry and restoring the number of edge transition pixels to around 3 pixels, which is also a significant improvement compared to existing image acquisition devices. Furthermore, the image acquisition device in this application embodiment can also effectively eliminate reflective interference caused by warped surfaces and the influence of non-contact areas on imaging, resulting in uniform and consistent image quality acquired by the imaging module.

[0064] After the silicone plate is pressed onto the battery plate and the welding strip is pressed onto the welding contact point of the battery cell by the silicone plate, the image acquisition device described in the embodiments of this application can eliminate the interference of the silicone plate on the imaging of the battery cell, obtain a clear, reliable and stable image of the battery cell, thereby obtaining accurate position coordinate information of the point to be welded, so that the laser welding unit can accurately emit light according to the position coordinate information of the point to be welded, and obtain a good welding effect.

[0065] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical parts between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant parts can be referred to the method section.

[0066] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0067] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An image acquisition device, characterized in that, It includes a light source module and an imaging module. The light beam emitted by the light source module illuminates the battery cell covered with a silicone plate, and the imaging module captures the image of the illuminated battery cell. The imaging module allows light beams within a preset wavelength range to pass through, and the wavelength of the light beam emitted by the light source module is within the preset wavelength range. The light source module includes a first light source arranged on both sides of the battery cell along a first direction and a second light source arranged on both sides of the battery cell along a second direction. The first direction and the second direction are perpendicular to each other in the same plane, and the first direction is the extension direction of the solder strip. A second light source, a first light source, and an imaging module are arranged sequentially above the battery cell from bottom to top. The beams emitted by the first and second light sources are both at a preset angle, illuminating the battery cell obliquely from top to bottom.

2. The image acquisition device according to claim 1, characterized in that, The imaging module includes a camera, a lens, and a filter. One end of the lens is connected to the camera, and the filter is installed at the other end of the lens. The filter allows light beams within a preset wavelength range to pass through the lens and then the camera in sequence.

3. The image acquisition device according to claim 2, characterized in that, Both the first and second light sources are strip-shaped light sources, and their lengths are greater than the length of the corresponding side of the battery cell; and / or, The light source module emits infrared light with a wavelength of 850μm, and the preset wavelength range is 810~870μm.

4. The image acquisition device according to any one of claims 1-3, characterized in that, The preset angle is 30 to 60°.

5. The image acquisition device according to any one of claims 1-3, characterized in that, In the height direction, the vertical distance between the second light source and the battery cell is 150-250 mm.

6. The image acquisition device according to any one of claims 1-3, characterized in that, In the height direction, the vertical distance between the first light source and the second light source is 50-100mm.

7. The image acquisition device according to claim 2 or 3, characterized in that, In the height direction, the vertical distance between the filter and the battery cell is 300-400 mm.

8. The image acquisition device according to any one of claims 1-3, characterized in that, The distance between the projection of the imaging module's field of view center onto the battery cell and the center of the battery cell is -100 to 100 mm.

9. The image acquisition device according to any one of claims 1-3, characterized in that, The distance between the projection of each first light source and each second light source onto the plane of the solar cell and the center of the solar cell is 100-150 mm.

10. A photovoltaic module laser welding system, characterized in that, It includes the image acquisition device according to any one of claims 1-9, and an arrangement unit disposed at the front end of the image acquisition device and a laser welding unit disposed at the rear end of the image acquisition device along the photovoltaic module conveying direction. The arrangement unit is used to press the silicone plate onto the entire battery panel, and to press the welding strip onto the welding contact point of the battery cell through the silicone plate; After receiving the position information of the battery cell from the image acquisition device, the laser welding unit emits a laser beam that passes through the silicone plate to weld the welding strip to the welding contact point.

Images