Flatness information acquisition device

Abstract

The application relates to the technical field of battery production, and provides a flatness information acquisition device. According to the flatness information acquisition device provided in the application, after a battery monomer is positioned on a bearing plane, the flatness information acquisition device provided in the application is used to press down the tab by a leveling member to level the tab, so that the bending or folding of the tab does not interfere with the acquisition of the flatness of the tab. Then, after the tab is leveled, the flatness information acquisition device provided in the application is used to irradiate the tab by using a light source member, and the tab is irradiated at an angle of less than or equal to 15 degrees with the bearing plane of the bearing member used for bearing the battery monomer, so that the protrusions and recesses on the surface of the tab are presented in longer shadows and more obvious dark areas under the irradiation of the inclined light, and the flatness of the tab is acquired by using an image acquisition member.

Description

Technical Field

[0001] This application relates to the field of battery manufacturing technology, and in particular to a flatness information acquisition device. Background Technology

[0002] In the manufacturing process of lithium-ion batteries, electrolyte corrosion and oxidation cannot be completely avoided on the tabs. If such problems occur, grinding is necessary to remove corrosion points and oxide layers, ensuring the reliability and quality of subsequent laser welding. The flatness of the tabs after grinding is one of the key factors affecting welding quality. Poor flatness can lead to uneven energy distribution during welding, resulting in defects such as incomplete welds, sparking, and insufficient weld strength, seriously affecting the safety and lifespan of the battery.

[0003] Currently, information on the flatness of the polished tabs is mainly obtained through two methods: manual acquisition and acquisition using contact tools.

[0004] Sensory assessment: Operators obtain information about the flatness of the tabs by visual inspection or by scratching the surface with their fingernails, relying on experience. This method is highly subjective, lacks standardized criteria, is inefficient, and prone to misjudgment due to operator fatigue, failing to meet the quality control requirements of modern high-speed production lines.

[0005] Contact tool inspection: such as using a knife-edge ruler in conjunction with a feeler gauge for measurement. Although this method can obtain some quantitative data, the measurement efficiency is low. At the same time, contact measurement carries the risk of scratching the clean surface of the electrode tabs and is not sensitive to minor, localized unevenness. Utility Model Content

[0006] In view of this, this application provides a flatness information acquisition device, which aims to solve the above-mentioned technical problems to a certain extent.

[0007] This application provides a flatness information acquisition device, which is used to inspect the flatness of the tabs of a battery cell. The flatness information acquisition device includes: A support member, the support member including a support plane, the support plane being used to position the battery cell; A leveling component, which is capable of being raised and lowered to press against the electrode lug; A light source component is disposed on the outside of a support component. The light source component is movable relative to the support component and its position is configured to illuminate the electrode tab at an angle of less than or equal to 15 degrees relative to the support plane. An image acquisition component is disposed on the outside of the supporting component, and the image acquisition component is used to acquire an image of the electrode tab.

[0008] Based on the above technical features, the flatness information acquisition device may optionally include a positioning mechanism, which includes two sets of positioning and pushing components arranged opposite to each other, and the two sets of positioning and pushing components can approach each other to clamp the battery cell.

[0009] Based on the above technical features, optionally, a bearing recess is provided on the bearing plane, the bearing recess being used to accommodate the battery cell for positioning the battery cell.

[0010] Based on the above technical features, optionally, the bearing plane has a predetermined extension direction. The flatness information acquisition device includes two light source components that are opposite to each other in the predetermined extension direction.

[0011] Based on the above technical features, optionally, the flatness information acquisition device further includes a platform component, wherein the bearing component, the light source component, and the leveling component are all disposed on the platform component.

[0012] Based on the above technical features, optionally, the flatness information acquisition device further includes a two-axis module and a frame, the two-axis module connecting the platform component and the frame, and the two-axis module being able to drive the platform component to move in the horizontal plane.

[0013] Based on the above technical features, optionally, the frame includes four columns and two beam members, each beam member connecting two columns, and the two-axis module is mounted on the beam members.

[0014] Based on the above technical features, optionally, the image acquisition component is mounted on the column and can move up and down along the column.

[0015] Based on the above technical features, optionally, the load-bearing member is movably connected to the platform member, so that the load-bearing member can move relative to the platform member.

[0016] Optionally, based on the above technical features, the load-bearing member can rotate relative to the platform member.

[0017] According to the flatness information acquisition device provided in this application, after the battery cell is positioned on the supporting plane, the device flattens the tab by pressing down on it using a leveling component, thus preventing bending or wrinkles of the tab from interfering with the acquisition of the tab's flatness. Next, after the tab is leveled, the device illuminates the tab using a light source component. Specifically, the light source illuminates the tab at an angle of less than or equal to 15 degrees to the supporting plane of the supporting component that carries the battery cell. This causes the protrusions and depressions on the tab surface to appear as longer shadows and more obvious dark areas under the oblique light, thereby allowing the image acquisition component to obtain the flatness of the tab.

[0018] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram showing a three-dimensional view of the flatness inspection device provided according to an embodiment of this application, with some parts of the structure omitted.

[0021] Figure 2 This is a schematic diagram of another three-dimensional view of the flatness inspection device provided according to an embodiment of this application, with some parts of the structure omitted.

[0022] Figure 3 A schematic diagram showing a three-dimensional view of a portion of the structure of a flatness inspection device provided according to an embodiment of this application is shown.

[0023] Figure 4 This is a schematic diagram showing a three-dimensional view of another part of the structure of the flatness inspection device provided according to an embodiment of this application.

[0024] Figure label: 100 - Load-bearing component; 110 - Load-bearing plane; 111 - Load-bearing recess; 200-cell battery; 310 - Leveling component; 320 - Light source component; 400 - Image Acquisition Component; 500 - Positioning mechanism; 510 - Push rod component; 600-Telescopic pole; 700 - Two-axis module; 800 - Platform component; 900 - Frame; 910 - Column; 920 - Beam component; 1000 - Barcode scanner. Detailed Implementation

[0025] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0028] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0029] According to an embodiment of this application, a flatness information acquisition device is provided, which will be described below in conjunction with... Figures 1 to 4 Describe in detail the structure and working principle of the flatness information acquisition device.

[0030] According to the flatness information acquisition device provided in the embodiments of this application, the flatness information acquisition device is used to inspect the flatness of the tabs of the battery cell 200. The flatness information acquisition device includes a bearing member 100, a leveling member 310, a light source member 320, and an image acquisition member 400.

[0031] In this embodiment, the supporting member 100 includes a supporting plane 110 for positioning the battery cell 200; the leveling member 310 is movable to press against the tab.

[0032] In this embodiment, the light source component 320 is disposed on the outside of the support component 100, and the light source component 320 is capable of being raised and lowered relative to the support component 100. The position of the light source component 320 is configured to illuminate the tab at an angle of less than or equal to 15 degrees relative to the support plane 110.

[0033] In this embodiment, the image acquisition component 400 is disposed on the outside of the support component 100, and the image acquisition component 400 is used to acquire the image of the tab.

[0034] According to the flatness information acquisition device provided in this application embodiment, after positioning the battery cell 200 on the bearing plane 110, the flatness information acquisition device provides the flatness information acquisition device in this application embodiment presses down on the tab by the flattening member 310 to flatten the tab, avoiding the interference of the bending or wrinkling of the tab on the acquisition of the flatness of the tab. Then, after the tab is flattened, according to the flatness information acquisition device provided in this application embodiment, the tab is illuminated by the light source member 320. Specifically, the tab is illuminated at an angle of less than or equal to 15 degrees with the bearing plane 110 of the bearing member 100 that supports the battery cell 200. This makes the protrusions and depressions on the surface of the tab appear as longer shadows and depressions as more obvious dark areas under the illumination of the oblique light, so that the flatness of the tab can be acquired by the image acquisition member 400.

[0035] Thus, the flatness information acquisition device provided according to the embodiments of this application not only avoids the uncertainty of manually acquiring the flatness of the tab, but also improves the efficiency of acquiring flatness information.

[0036] The flatness information acquisition device provided according to the embodiments of this application further includes a positioning mechanism 500. The positioning mechanism 500 includes two sets of positioning pushing members arranged opposite to each other. The two sets of positioning pushing members can approach each other to clamp the battery cell 200, thereby effectively positioning the battery cell 200 and preventing the battery cell 200 from shaking and interfering with the acquisition of the flatness of the tab.

[0037] In this embodiment, the pushing member can be, for example, a push rod, the power of which can come from a cylinder. For instance, the push rod can be connected to the piston rod of the cylinder, so that the push rod can be used to push the battery cell 200, thereby changing the position of the battery cell 200 relative to the bearing plane. Here, the two sets of pushing members can be arranged opposite each other along a first horizontal direction, and the battery cell 200 is positioned between the two sets of pushing members.

[0038] In an embodiment, the supporting member 100 may be, for example, a rectangular plate structure, and the supporting plane may be, for example, the upper end face of the rectangular plate structure, which obviously has a rectangular shape. In an embodiment, the light source member 320 may be disposed outside the supporting member 100 and spaced apart from the supporting member 100. For example, the light source member 320 may be disposed on the platform member 800 described below, which will be explained in the following description.

[0039] According to the flatness information acquisition device provided in the embodiments of this application, a bearing recess 111 is provided on the bearing plane. The bearing recess 111 is used to accommodate the battery cell 200 for positioning the battery cell 200. The bearing recess 111 can be configured to mimic the shape of the battery cell 200, and its size can be slightly larger than the size of the battery cell 200, or the same as the size of the battery cell 200.

[0040] In the embodiments, according to the flatness information acquisition device provided in the embodiments of this application, the battery cell 200 can be a square battery, that is, a cuboid-shaped battery. Therefore, the bearing recess 111 can be, for example, a cuboid groove.

[0041] Furthermore, in the embodiment, the internal dimensions of the bearing recess 111 may be slightly larger than the dimensions of the battery cell 200, thereby facilitating the fine adjustment of the position of the battery cell 200 by the push rod member 510 as described above within the bearing recess 111.

[0042] In an embodiment, the supporting recess 111 may generally include two parts: one part for accommodating the main body of the battery cell 200, and the other part for accommodating the tab portion of the battery cell 200. In an embodiment, the number of tabs of the battery cell 200 may be, for example, two.

[0043] In this embodiment, for the existing battery cell 200, there are two types of battery cells 200: those with tabs on both sides and those with tabs on only one side. Therefore, the supporting recess 111 can be designed accordingly for both types of battery cells 200.

[0044] Specifically, the supporting recess 111 may have two grooves on one side of the first horizontal direction to accommodate the tabs, thereby adapting to the battery cell 200 with a single-sided tab. In addition, the supporting recess 111 may also have two grooves on each side of the second horizontal direction perpendicular to the first horizontal direction, which are used to adapt to the battery cells with tabs on both sides.

[0045] like Figure 4As shown, according to the flatness information acquisition device provided in the embodiment of this application, the battery cell 200 has a first tab and a second tab respectively disposed on opposite sides of the battery cell 200. The flatness information acquisition device includes two light source components 320 located on one side of the first tab and the other side of the second tab. Thus, each tab is provided with a corresponding light source component 320 to ensure the accuracy of the tab image acquired by the image acquisition component 400.

[0046] In an embodiment, as an example, the light source component 320 may be, for example, an LED light source. In another embodiment, two light source components 320 may be positioned adjacent to the two corners of the supporting component 100, arranged diagonally opposite each other, so that one light source component 320 can illuminate both sides of the battery cell 200. As an example, when acquiring flatness information, only the light source component 320 closest to the electrode tab may be activated.

[0047] In an embodiment, the leveling member 310 may include an L-shaped leveling rod, the upper part of which may be horizontal and positioned above the tab, so that the tab can be pressed into the groove where the tab is located when the leveling rod is raised or lowered.

[0048] In this embodiment, the leveling member 310 can be raised or lowered by an electric telescopic rod or a cylinder, which can also be mounted on the platform described below.

[0049] like Figure 4 As shown, Figure 4 An example of the leveling component 310 is shown schematically. Figure 4 Only two leveling members 310, arranged opposite each other in the second horizontal direction, are shown. These two leveling members 310 are applicable to the battery cell 200 with tabs on both sides as described above. But not limited to Figure 4 As shown, for the two tab receiving grooves on one side in the first horizontal direction, two identical flattened components can also be provided.

[0050] It should be noted that, although Figure 4 The positioning mechanism 500 interferes with the two tab receiving grooves on one side in the first horizontal direction, but Figure 4 The position of the positioning mechanism 500 is only an illustrative example. In the actual setting of the positioning mechanism 500, the positioning push rod of the positioning mechanism 500 is located on the outside of the electrode receiving groove in the second horizontal direction to avoid interference with the electrode.

[0051] According to the flatness information acquisition device provided in the embodiments of this application, the flatness information acquisition device may further include a platform component 800, a bearing component 100, a light source component 320 and a leveling component 310, all of which may be disposed on the platform component 800, as mentioned in the above description, and will not be repeated here.

[0052] According to the flatness information acquisition device provided in the embodiments of this application, the flatness information acquisition device further includes a two-axis module 700 and a frame 900. The two-axis module 700 connects the platform component 800 and the frame 900. The two-axis module 700 can drive the platform component 800 to move in the horizontal plane. Thus, when the image acquisition component 400 is located on the outside of the platform component 800, the battery cell 200 can be driven by the platform component 800 to change its position to adapt to the position of the image acquisition component 400.

[0053] like Figures 1 to 3 As shown, Figure 1 and Figure 2 The connection method between the frame 900 and the platform is shown. According to the flatness information acquisition device provided in the embodiment of this application, the frame 900 includes four columns 910 and may also include two beam members 920. Each beam member 920 is connected to two columns 910, and the two-axis module 700 is mounted on the beam member 920.

[0054] According to the flatness information acquisition device provided in the embodiments of this application, the beam member 920 can extend along the second horizontal direction. In the embodiment, the module providing degrees of freedom along the second horizontal direction in the biaxial module 700 includes two parts, both of which can be electric slides, and are respectively arranged along the two beam members 920. The module providing degrees of freedom along the first horizontal direction in the biaxial module 700 is mounted on two electric slides and connected to the platform member 800 through a longitudinal beam, so that the platform, as well as the above-mentioned components and battery cells 200 connected to the platform, can all move in the plane.

[0055] According to the flatness information acquisition device provided in the embodiments of this application, the image acquisition component 400 is mounted on the column 910 and can move up and down along the column 910. In this way, the motion freedom of the image acquisition component 400 and the two-axis module 700 together provide three degrees of freedom for the relative motion between the image acquisition component 400 and the tab.

[0056] In this embodiment, as an example, the image acquisition component 400 can be set to correspond to the column 910. That is, the number of image acquisition components 400 can be the same as the number of columns 910, and they can be raised and lowered on the corresponding column 910 by a separate sliding table. This makes it convenient to take pictures of the electrode under different angles according to actual needs.

[0057] According to the flatness information acquisition device provided in the embodiments of this application, the supporting member 100 can be movably connected to the platform member 800 so that the supporting member 100 can move relative to the platform member 800. As an example, the supporting member 100 can rotate relative to the platform member 800, thereby adjusting the position of the battery cell 200 as needed, thus ensuring that the tabs of the battery cell 200 can be photographed from different angles.

[0058] Based on the technical solutions described above, the following will specifically describe a particular example of the flatness information acquisition device provided according to the embodiments of this application.

[0059] In this embodiment, the supporting member 100 can be, for example, an inspection tray. The vertical direction of the inspection tray is a groove shaped like a battery with tabs on both sides, and the horizontal direction is a groove shaped like a battery with tabs on one side. A silicone pad can be provided inside the supporting recess 111, which is laid flat on the bottom of the entire supporting recess 111 and is consistent with the shape of the main body of the battery cell 200 and the tab groove, forming a contour positioning to protect the main body of the battery cell 200 and the outside of the tab.

[0060] In this embodiment, the light source component 320 can be, for example, an LED light source mechanism (the light source mechanism may include two telescopic rods 600 and a rotating shaft; the height of the light source can be adjusted by the vertical telescopic rod, and the position can be adjusted by the horizontal telescopic rod; simultaneously, the two telescopic rods (e.g., multi-section telescopic rods in the prior art) can rotate together via a hollow rotating shaft, thereby adjusting the angle of illumination by the light source). Here, a bendable corrugated tube can also be used to connect the LED light source mechanism, and wires can be routed through the corrugated tube, with the ends of the wires connected to the LED power supply and control switch; these components can also be integrated onto the platform component 800.

[0061] In this embodiment, the image acquisition component 400 can be, for example, a CCD camera (the position and angle of the CCD camera can be adjusted by a slide rail), and a set of robotic arm structures (i.e., the existing two-axis module 700 mentioned above) can be added above the column 910. At the same time, the robotic arm is connected to the platform component 800. There is an inspection tray on the platform component 800. The bottom of the bearing recess 111 of the inspection tray can be equipped with a sensing fiber (the sensing fiber can be embedded in the bottom of the inspection tray and is flush with the bottom of the inspection tray).

[0062] In this embodiment, a barcode scanner 1000 can also be installed on the inspection tray. The barcode scanner 1000 is connected to the inspection platform via a vertical telescopic rod (such as using a cylinder for lifting). A rotating fixing mechanism (mainly composed of a deep groove ball bearing, a stepped driven shaft, and a flip plate fixing seat, and externally connected to a servo motor) is connected between the inspection platform and the inspection tray by screws. Specifically, the driven shaft can pass through the inspection platform and the flip plate fixing seat, and the flip plate fixing seat is set between the inspection platform and the inspection tray. The driven shaft can lift the inspection tray. A deep groove ball bearing is set between the driven shaft and the flip plate fixing seat. The servo motor can be connected to the driven shaft and can be fixed on the lower side of the inspection platform.

[0063] In this embodiment, the battery to be inspected is picked up from the conveyor belt by a robotic arm and placed in the groove of the inspection tray. The sensing fiber (which identifies the presence of a battery by the attenuation of light intensity) senses the battery and gives a signal. The positioning structure pushes the push rod components 510 on both sides towards the middle through a cylinder, thereby precisely positioning the battery.

[0064] After positioning, a barcode scanning operation is performed. After completion, the battery tabs are leveled (the bent or otherwise bent battery tabs are leveled to avoid misjudgment). After leveling, a signal is sent to the PLC, which in turn sends a signal to the CCD camera. The camera then focuses and takes a picture under the illumination of an LED light source (with the tray plane (i.e., the bearing plane 110) at an angle of less than or equal to 15 degrees) to obtain flatness image information.

[0065] Based on the flatness information acquisition device provided in the embodiments of this application, image information can be uploaded to an industrial control computer, the industrial control computer processes the information and sends the judgment result to a PLC, and the PLC performs corresponding processing on the battery according to the result.

[0066] In this embodiment, the flatness information acquisition device provided according to the embodiments of this application can be used to further verify this information. The specific information acquisition and verification steps are as follows: The battery cells to be inspected are transported to the inspection station by a conveyor belt (the inspection station mainly consists of a battery inspection tray, a positioning structure, a CCD camera, and an LED light source), and the positioning fixtures fix them in place.

[0067] A ring-shaped LED light source illuminates the polished surface of the tab at a low angle of less than 15 degrees. This lighting method can transform minute unevenness into obvious contrast between light and dark (i.e., the "shadow effect").

[0068] The CCD camera is triggered to capture high-definition images (e.g., 5 megapixels) of the tab surface and transmit the images to the industrial control computer.

[0069] The software within the industrial control computer executes the following algorithm flow: Preprocessing: The color image is converted to grayscale, and Gaussian filtering is used for noise reduction.

[0070] Macroscopic Recognition: The preprocessed image is input into a pre-trained YOLOv5 model. This model can identify two types of defects: "scratches" and "dents." If either defect is detected with a confidence level greater than 90%, a non-compliance signal is immediately sent to the PLC.

[0071] Microscopic assessment: For images where no macroscopic defects are found, quantitative analysis is performed.

[0072] Calculate its gray-level co-occurrence matrix (GLCM) and extract two features: contrast and energy.

[0073] Calculate the gradient magnitude variance of the image to characterize the degree of drastic change in brightness on the surface.

[0074] These three features (contrast, energy, and gradient magnitude variance) are input into a support vector machine regression model. This regression model is pre-trained using a large number of samples with known smoothness. The regression model outputs a smoothness score from 0 to 100.

[0075] Judgment: The passing threshold is set at a score ≥ 80. If the score of the electrode is ≥ 80, it is judged as passing; otherwise, it is judged as failing.

[0076] Execution: The industrial control system sends the judgment result to the PLC, the PLC controls the rejection mechanism to remove the non-conforming products from the production line, and records and displays the current inspection result statistics on the MES system.

[0077] The above are merely preferred embodiments of this application and do not limit the scope of protection of this application. Any equivalent structural transformations made based on the innovative concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the scope of protection of this application.

Claims

1. A device for acquiring flatness information, characterized in that, The flatness information acquisition device is used to inspect the flatness of the tabs of a single battery cell. The flatness information acquisition device includes: A support member, the support member including a support plane, the support plane being used to position the battery cell; A leveling component, which is capable of being raised and lowered to press against the electrode lug; A light source component is disposed on the outside of a support component. The light source component is movable relative to the support component and its position is configured to illuminate the electrode tab at an angle of less than or equal to 15 degrees relative to the support plane. An image acquisition component is disposed on the outside of the supporting component, and the image acquisition component is used to acquire an image of the electrode tab.

2. The flatness information acquisition device according to claim 1, characterized in that, The flatness information acquisition device further includes a positioning mechanism, which includes two sets of positioning and pushing components arranged opposite to each other. The two sets of positioning and pushing components can approach each other to clamp the battery cell.

3. The flatness information acquisition device according to claim 2, characterized in that, The bearing plane is provided with a bearing recess, which is used to accommodate the battery cell for positioning the battery cell.

4. The flatness information acquisition device according to claim 1, characterized in that, The bearing plane has a predetermined extension direction. The flatness information acquisition device includes two light source components that are opposite to each other in the predetermined extension direction.

5. The flatness information acquisition device according to claim 1, characterized in that, The flatness information acquisition device further includes a platform component, and the bearing component, the light source component, and the leveling component are all disposed on the platform component.

6. The flatness information acquisition device according to claim 5, characterized in that, The flatness information acquisition device also includes a two-axis module and a frame. The two-axis module connects the platform component and the frame, and the two-axis module can drive the platform component to move in the horizontal plane.

7. The flatness information acquisition device according to claim 6, characterized in that, The frame includes four columns and two beam members, each beam member connecting two columns, and the two-axis module is mounted on the beam members.

8. The flatness information acquisition device according to claim 7, characterized in that, The image acquisition component is mounted on the column and can move up and down along the column.

9. The flatness information acquisition device according to claim 5, characterized in that, The load-bearing member is movably connected to the platform member so that the load-bearing member can move relative to the platform member.

10. The flatness information acquisition device according to claim 9, characterized in that, The load-bearing component is rotatable relative to the platform component.

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