Inspection device

Abstract

An inspection device for inspecting the quality of an electrode material for a battery by an optical method, the inspection device being provided with: a plurality of illuminations for irradiating inspection light to the surface of the electrode material; the inspection apparatus includes a plurality of illuminations, each of the plurality of illuminations including a first illumination, the incident angle of which is set such that specular reflected light, which is reflected by the surface of the electrode material, of the irradiated inspection light is incident on the imaging unit, and an adjustment unit that adjusts the incident angle of the first illumination so that the specular reflected light is reflected by the surface of the electrode material. The adjustment unit adjusts or sets a predetermined condition in such a manner that in the imaging unit, the signal intensity acquired on the basis of the reflected light of the inspection light irradiated from the first illumination among the plurality of illuminations is selectively reduced.

Description

Technical Field

[0001] The present invention relates to an inspection device for inspecting the quality of an electrode material for a battery by an optical method. Background Art

[0002] Conventionally, inspection devices or monitoring devices are known for measuring the dimensions of specific points or areas on the surface of an object being conveyed in a predetermined direction or rotating about an axis in a predetermined direction, or for detecting defects such as foreign matter or flaws. These devices can easily and accurately inspect the quality of objects, prevent the accidental discharge of defective products, and improve yield (for example, see Patent Documents 1 to 3).

[0003] However, depending on the type of object, even using the inspection devices or monitoring devices described in Patent Documents 1 to 3, it is sometimes difficult to inspect the quality of the object. As an example of such an object, an electrode material for a battery (e.g., a lithium-ion secondary battery) can be cited. The reflectivity of the surface of the electrode material varies depending on the region. For example, when using the inspection devices or monitoring devices described in Patent Documents 1 to 3, it is difficult to detect the boundaries between such regions in the captured image of the surface of the electrode material. Therefore, the accuracy of measuring the size of a specific region may be reduced. In addition, the accuracy of detecting foreign matter and defects in regions with low reflectivity may also be reduced.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-020873

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2014-178249

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 2012-251929 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The technology disclosed herein has been developed to solve the above-mentioned problem, and an object thereof is to provide an inspection device capable of inspecting the surface of an inspection object with high precision, even when the reflectivity of the surface of the inspection object varies depending on the area.

[0011] Means for solving problems

[0012] The present disclosure for solving the above-mentioned problems is an inspection device, which inspects the quality of electrode materials for batteries by optical methods, and is characterized in that the inspection device includes: multiple illuminations, which irradiate inspection light to the electrode material; and a shooting unit, which respectively receives reflected light of the inspection light irradiated from the multiple illuminations and reflected by the surface of the electrode material, and shoots the surface of the electrode material, the multiple illuminations include a first illumination, the incident angle of the first illumination is set so that the specular reflected light of the irradiated inspection light reflected by the surface of the electrode material is incident on the shooting unit, and the inspection device also includes an adjustment unit, which adjusts or sets a specified condition in the following manner: in the shooting unit, the signal intensity obtained based on the reflected light of the inspection light irradiated from the first illumination among the multiple illuminations and reflected by the surface of the electrode material is selectively reduced.

[0013] The surface of the electrode material that is the inspection object of the inspection device disclosed herein often includes areas with greatly different reflectivities. Therefore, when the surface of the electrode material is photographed by a photographing unit such as a monochrome camera that is included in conventional inspection devices, it may be impossible to inspect the surface of the electrode material with high precision because the obtained photographed image contains areas that are too bright and areas that are too dark. By using the inspection device disclosed herein, the above-mentioned problem can be eliminated, that is, it is possible to detect the boundaries between areas with greatly different reflectivities in the photographed image obtained from the photographing unit. Here, the above-mentioned "selective reduction of signal intensity" means that the degree of reduction of the signal intensity based on the first illumination is relatively large relative to that of other illuminations. In addition, this only indicates the degree of change, and the size of the signal intensity after the change itself is not limited. In addition, the above-mentioned "adjustment or setting" includes both the case of adjusting the conditions during or before the inspection and the case of setting the conditions during design or manufacturing.

[0014] Furthermore, in the present disclosure, the plurality of illuminations may include a second illumination that emits inspection light having a different wavelength and incident angle than the first illumination, the imaging unit receiving reflected light from the surface of the electrode material of the inspection light emitted by the first illumination and reflected light from the surface of the electrode material of the inspection light emitted by the second illumination, respectively, and the inspection device acquiring an image capable of distinguishing the uneven shape of the surface of the electrode material based on the difference in color. This facilitates quality evaluation of the electrode material.

[0015] Furthermore, in the present disclosure, the prescribed condition may be the intensity of the inspection light irradiated from the first illumination, or the sensitivity of the imaging unit to the reflected light of the inspection light irradiated from the first illumination, which is reflected from the surface of the electrode material. Thus, the signal intensity obtained based on the reflected light reflected from the surface of the electrode material can be easily adjusted or set. Furthermore, in addition to the intensity of the inspection light irradiated from the first illumination, the sensitivity of the imaging unit to the reflected light of the inspection light irradiated from the first illumination, the prescribed condition may also include the setting angle of the first illumination, the distance between the first illumination and the electrode material, etc. Furthermore, it may also include installing a neutral density filter or an aperture in the first illumination.

[0016] Furthermore, in the present disclosure, the signal intensity obtained by the reflected light reflected from the surface of the electrode material based on the inspection light irradiated from the first illumination may be reduced to less than 1 percent by the adjustment unit. Generally, the signal intensity obtained based on the mirror reflected light is higher than the signal intensity obtained based on the diffuse reflected light. Therefore, without adjusting the signal intensity obtained by the reflected light reflected from the surface of the electrode material based on the inspection light irradiated from the first illumination, the signal intensity obtained by the imaging unit may exceed the allowable value by setting the incident angle so that the mirror reflected light reflected from the surface of the electrode material enters the first illumination of the imaging unit, or may not be able to perform proper imaging due to the relationship with the intensity of the inspection light from other illuminations. Therefore, by setting a limit to reduce the signal intensity to less than 1 percent, this problem can be eliminated.

[0017] Furthermore, in the present disclosure, the plurality of illuminations may include infrared illumination, the infrared illumination emitting infrared light as the inspection light, and the infrared illumination emitting the inspection light at the highest illumination intensity among the plurality of illuminations. Thus, in an image captured by the imaging unit that receives reflected infrared light, it is possible to easily detect darker foreign matter in an area that appears dark due to low reflectivity to visible light.

[0018] Furthermore, in the present disclosure, the incident angles of the inspection light from the multiple illuminations may be different, and the absolute value of the incident angle of the inspection light from the first illumination may be the smallest among the incident angles of the inspection light from the multiple illuminations. Thus, the angle adjustment between the first illumination and the imaging unit becomes easier, and the mirror-reflected light of the first illumination can be made to be incident on the imaging unit more reliably or easily. Furthermore, the difference between the incident angle of the inspection light of illumination other than the first illumination, which causes the diffusely reflected light to be incident on the imaging unit, and the incident angle of the first illumination can be increased, thereby making it possible to more reliably make the diffusely reflected light from illumination other than the first illumination and the mirror-reflected light of the illumination incident on the imaging unit separately.

[0019] Furthermore, in the present disclosure, the electrode material for the battery may be formed by applying a coating of active material to a metal sheet. The coating significantly affects the quality of the electrode material, and its quality evaluation is essential in electrode material production. By being able to detect the boundary between the metal sheet with a relatively high reflectivity and the coating with a relatively low reflectivity in the camera image, dimensions such as the width of the coating can be easily measured, resulting in improved electrode material quality.

[0020] Furthermore, in the present disclosure, the boundary between the coating and the metal sheet may be detected using reflected light from the inspection light emitted by the first illumination device, and the size of the coating may be measured by detecting the boundary between the coating and the metal sheet. By using the specularly reflected light from the inspection light emitted by the first illumination device, the boundary between the coating and the metal sheet is more clearly displayed in the captured image. This allows for more efficient size measurement.

[0021] Furthermore, in the present disclosure, the plurality of illuminations may further include illumination for emitting red light, illumination for emitting blue light, and illumination for emitting green light. Thus, if a defect such as a foreign object or unevenness is present in the captured image, the wavelength of the reflected light incident on the imaging unit can be varied according to the shape of the defect, and the defect can be clearly displayed by combining light of different wavelengths according to the type of defect on the surface of the electrode material.

[0022] Furthermore, the present disclosure is an inspection device that inspects the quality of an electrode material for a battery by an optical method, and is characterized in that the inspection device comprises: a plurality of illuminations that irradiate inspection light onto the surface of the electrode material; and a photographing unit that respectively receives reflected light of the inspection light irradiated from the plurality of illuminations and reflected from the surface of the electrode material, and photographs the surface of the electrode material, the plurality of illuminations including a first illumination, the incident angle of the first illumination being set so that the specular reflected light of the irradiated inspection light reflected from the surface of the electrode material is incident on the photographing unit, the reflected light of the inspection light irradiated from the first illumination is used to detect the boundary between the coating and the metal sheet, thereby enabling the size of the coating to be measured, and the reflected light of the inspection light irradiated from illuminations other than the first illumination among the plurality of illuminations and reflected from the surface of the electrode material, enabling defects or foreign matter in the coating or the metal sheet to be detected.

[0023] That is, the inspection device disclosed in the present invention can not only measure the dimensions of the coated material, but also detect defects or foreign matter in the coated material. This allows for more detailed quality evaluation of the electrode material, making it easier to predict the results of improving the quality of the electrode material.

[0024] In addition, the means for solving the above-mentioned problems can be used in combination with each other as much as possible.

[0025] Effects of the Invention

[0026] According to the technology disclosed in the present invention, in an inspection object whose surface reflectance varies depending on the region, it is possible to inspect the surface of the inspection object with high precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is an explanatory diagram schematically showing the configuration of an inspection device according to an embodiment.

[0028] Figure 2 A is an RGB image showing a plan view of the electrode material of the example. Figure 2 B is Figure 2 The portion surrounded by the dotted line X in A corresponds to an enlarged view of the image. Figure 2 C is Figure 2 An enlarged view of the portion surrounded by the dotted line Y in A.

[0029] Figure 3 A is an infrared image showing a plan view of the electrode material of the example. Figure 3 B is Figure 3 An enlarged view of the portion surrounded by the dotted line Z in A.

[0030] Figure 4 A is a schematic diagram of the relative position of the red light illumination with respect to the line scan camera. Figure 4 B is a schematic diagram of the relative position of the infrared light illumination with respect to the line scan camera.

[0031] Figure 5 A is a schematic diagram of the relative position of the green light illumination with respect to the line scan camera. Figure 5 B is a schematic diagram of the relative position of the blue light illumination with respect to the line scan camera.

[0032] Figure 6 This is a schematic diagram showing an example of display content on a display unit included in the inspection device of the embodiment. DETAILED DESCRIPTION

[0033] [Application Examples]

[0034] Hereinafter, an outline of application examples of the present invention will be described using some drawings. Figure 1This is an explanatory diagram schematically showing the structure of an inspection device 1 that applies the technology in this application example. The inspection device 1 in this application example is configured to include a red light illuminator 11, an infrared light illuminator 12, a green light illuminator 13, and a blue light illuminator 14 as multiple illumination devices that irradiate the battery electrode material 2 with inspection light of different wavelengths from different angles. In addition, the inspection device 1 is configured to include a line scan camera 15 that independently receives each reflected light of the inspection light reflected from the surface of the electrode material 2 and images the surface of the electrode material 2, as well as a light intensity adjustment unit 161 that adjusts the intensity of each of the multiple illumination devices and a signal intensity adjustment unit 162 that adjusts the signal intensity of the line scan camera 15 relative to the intensity of the reflected light. Here, the line scan camera 15 is equivalent to the imaging unit in the present disclosure. Furthermore, the light intensity adjustment unit 161 and the signal intensity adjustment unit 162 are equivalent to the adjustment unit in the present disclosure.

[0035] Red light 11, infrared light 12, green light 13, and blue light 14, respectively, illuminate the electrode material 2 with red light 111, infrared light 121, green light 131, and blue light 141 as detection light. Red light 111, green light 131, and blue light 141 are types of visible light. The cones contained in the human retina are generally able to detect all colors by combining these three types of visible light in a predetermined ratio. Therefore, in the image captured by the line scan camera 15, if there is a defect on the surface of the electrode material 2, the wavelength of the reflected light incident on the line scan camera 15 can be varied according to the shape of the defect. This allows the defect to be clearly displayed by combining different wavelengths of light according to the type of defect.

[0036] about Figure 1 The red light illuminator 11 is shown relative to the line scan camera 15. The red light illuminator 11 and the line scan camera 15 are arranged so that the incident angle of the red light 111 is equal to the angle of the optical axis of the line scan camera 15 relative to the vertical line. This makes it easier for the line scan camera 15 to receive specularly reflected light of the red light 111 from the surface of the electrode material 2, and the signal intensity obtained based on this specularly reflected light is more likely to be high. Therefore, the light quantity adjustment unit 161 and the signal intensity adjustment unit 162 adjust or set the predetermined conditions so that the degree of reduction in this signal intensity is relatively greater than that of the other illuminations (infrared light illuminator 12, green light illuminator 13, and blue light illuminator 14).

[0037] As an example, the prescribed conditions may also include the intensity of the red light 111, the sensitivity of the line scan camera 15 to the reflected light of the red light 111 reflected by the surface of the electrode material 2, the setting angle of the red light illumination 11, the distance between the red light illumination 11 and the electrode material 2, etc. Furthermore, it may also include installing a neutral density filter or an aperture on the red light illumination 11. Furthermore, in this application example, adjustment means determining the conditions during or before the inspection, and setting means determining the conditions during design or manufacturing. In addition, regarding the relative position of the red light illumination 11 with respect to the line scan camera 15, the following embodiments use Figure 4 A will be described in detail. The red light illumination 11 corresponds to the first illumination in the present disclosure.

[0038] [Example]

[0039] Hereinafter, the following will be described using the accompanying drawings (including the examples temporarily described in the above application examples). Figure 1 ) The inspection device 1 according to the embodiment of the present disclosure will be described in more detail. In addition, the inspection device 1 according to the embodiment of the present disclosure is not limited to the following structure.

[0040] <Device Structure>

[0041] Here, return Figure 1 In addition, in the following embodiments, detailed descriptions of the contents described in the above application examples are omitted. In addition, in this specification, the same reference numerals are used to describe the same components.

[0042] about Figure 1 As described above, the inspection device 1 of this embodiment has four types of illumination. The signal intensity obtained based on the reflected light of the detection light irradiated by each illumination is adjusted according to the purpose of processing the electrode material 2. However, the number of illuminations can be multiple and is not limited thereto. In addition, multiple illuminations with equal wavelengths of irradiated inspection light can also be provided. Figure 4 A to Figure 5 B, the relative position of the line scan camera 15 with respect to the lighting is described, but the installation position of the lighting and the line scan camera 15 can also be changed appropriately. For example, Figure 1 The position of the red light illumination 11 and the position of the infrared light illumination 12 shown can be interchanged with each other, and the position of the green light illumination 13 and the position of the blue light illumination 14 can also be interchanged with each other.

[0043] Furthermore, the electrode material 2 to be inspected in this embodiment is a layer of a multi-layered electrode and is a sheet-like component. Specifically, the electrode material 2 is formed by applying a coating 22 of an active material capable of outputting electrical energy to a current collector such as an aluminum foil 21. The reflectivity of the aluminum foil 21 is higher than that of the coating 22, that is, the reflectivity of the surface of the electrode material 2 varies greatly depending on the region. Here, the aluminum foil 21 is equivalent to the metal sheet in the present disclosure. In addition, in Figure 1 In the process, the electrode material 2 is wound from a roller arranged on one side of the inspection device 1 to a winding roller arranged on the opposite side of the inspection device 1 by Figure 1 The four types of illumination shown are shown below the line camera 15. At this time, the surface of the electrode material 2 is irradiated with inspection light from each illumination, and the reflected light is incident on the line camera 15, thereby inspecting the surface condition of the electrode material 2.

[0044] Furthermore, the line scan camera 15 is useful in that it can capture the surface of a sheet-like component such as the electrode material 2 with high precision even during the conveyance of the component. Even if the surface of the electrode material 2 has irregularities, the irregularities can be clearly identified in the captured image. However, the camera used to capture the surface of the electrode material 2 is not necessarily limited to the line scan camera 15. For example, an area scan camera or a contact image sensor (CIS) can also be used. Furthermore, the direction in which the electrode material 2 is conveyed can of course be Figure 1 The direction of the arrow shown can also be the opposite direction. In addition, as long as the electrode material 2 moves at a certain speed under the illumination and line array camera 15, the mode of movement is not limited to conveying. For example, in the case where the electrode material 2 is a long strip that is difficult to be wound onto a roller, the following mode can also be used: the inspection device 1 is equipped with a clamp (not shown), and when the electrode material 2 is fixed to the clamp, the clamp repeatedly performs the following actions at equal intervals: Figure 1 After moving below the illumination and line array camera 15 in a certain range and at a certain speed in the direction of the arrow shown, Figure 1 The light intensity adjustment unit 161 and the signal intensity adjustment unit 162 can be adjusted manually or automatically. The infrared light 12 is set at the smallest angle, while the green light 13 or the blue light 14 is set at the largest angle.

[0045] Figure 2A is an RGB image showing a top view of the electrode material 2 in the embodiment. In this embodiment, an RGB image is an image obtained by extracting the wavelength components of visible light (i.e., red light 111, green light 131, and blue light 141) from the image captured by the line scan camera 15. As described above, the aluminum foil 21 and the coating 22 have different reflectivities. In the RGB image, the aluminum foil 21, with its higher reflectivity, appears brighter, while the coating 22, with its lower reflectivity, appears darker.

[0046] Figure 2 B is Figure 2 The portion surrounded by the dotted line X in A corresponds to an enlarged view of the image. In this embodiment, it is assumed that the mirror-reflected light of the red light 111 is incident on the line scan camera 15. Figure 2 A and Figure 2 In B, the aluminum foil 21 is shown in red. Figure 2 In B, by using an image obtained by extracting only the signal of the specular reflection light based on the red light 111, the aluminum foil 21 is displayed more brightly, and the boundary between the aluminum foil 21 and the coating 22 can be easily identified. Therefore, for example, the width of the coating 22 ( Figure 2 The coating 22 has a significant impact on the quality of the electrode material 2. Therefore, measuring the dimensions of the coating 22 is very important in evaluating the quality of the electrode material 2, and this can lead to improvements in the quality of the electrode material 2. Furthermore, in addition to the boundary between the aluminum foil 21 and the coating 22, for example, the boundary between wet and dry areas of the coating 22 can also be detected by differences in reflectivity between these areas.

[0047] Figure 2 C is Figure 2 An enlarged view of the portion surrounded by the dotted line Y in A. Figure 2 The area surrounded by white lines shown in C represents the defect 3 of the aluminum foil 21. Assume that the defect 3 has a concave-convex shape, and within the concave-convex shape, there are areas irradiated with green light 131 and areas irradiated with blue light 141. For the area irradiated with green light 131, the line scan camera 15 receives its reflected light and Figure 2 In the RGB image shown in C, it is displayed in green. Similarly, for the area irradiated with blue light 141, Figure 2The RGB image shown in C is displayed in blue. Specifically, if the aluminum foil 21 has a concave-convex defect 3, the wavelength of the reflected light incident on the line scan camera 15 can be varied according to the shape of the defect. The combination of inspection light with different wavelengths allows the shape of the defect 3 to be clearly displayed in the RGB image. This allows such defects 3 to be more reliably detected. Furthermore, foreign matter (not shown) as a defect in the aluminum foil 21 can also be detected using the RGB image, including the shape of the foreign matter. Here, the green light illumination 13 and the blue light illumination 14 correspond to the second illumination in this disclosure.

[0048] Figure 3 A is an infrared image of the electrode material 2 of the embodiment as viewed from above. In this embodiment, the infrared image is obtained by extracting the wavelength component of the infrared light 121 from the image captured by the line scan camera 15. Figure 2 Compared to the RGB image shown in A, the applied object 22 is displayed brightly in the infrared image. Figure 3 B is Figure 3 An enlarged view of the portion surrounded by the dotted line Z in Figure A. In the infrared image, the coating 22 appears brightly, making it easier to detect a defect 3 (more specifically, a dark defect) in the coating 22. This defect 3 is a convex defect occurring in the coating 22, and acquiring an infrared image allows for more reliable detection of such defects. Specifically, in the infrared image, the darker defect 3, which appears dark due to low reflectivity for visible light, can be easily detected. Furthermore, foreign matter (not shown) can also be detected as a defect in the coating 22 using infrared images.

[0049] As described above, an RGB image (or R image) is acquired when the boundary between the aluminum foil 21 and the coated material 22 is clearly displayed and the dimensions of the coated material 22 are measured. Furthermore, an RGB image is acquired when defects 3 or foreign matter in the aluminum foil 21 are detected, including their shapes. Furthermore, an infrared image is acquired when defects 3 or foreign matter in the coated material 22 are detected. Thus, the inspection apparatus 1 of the embodiment can extract any one or more of the four wavelength components of the inspection light from the image captured by the line scan camera 15, depending on the content of the inspection of the surface of the electrode material 2.

[0050] Next, use Figure 4 A to Figure 5 B, yes Figure 1 The relative position of the illumination in the inspection device 1 with respect to the line scan camera 15 is described in detail. Figure 4 A schematically shows the relative position of the red light illumination 11 with respect to the line scan camera 15. Figure 4In A, the red light illuminator 11 is set so that the angle θ1 between an imaginary line extending perpendicularly from the surface of the electrode material 2 and the center of the red light illuminator 11 (the incident angle θ1 of the red light 111) and the angle θ2 between the imaginary line and the center of the lens of the line scan camera 15 (the reflection angle θ2 of the red light 111) are equal, and the reflected light of the red light 111 is equivalent to the mirror reflection light. In addition, the incident angle θ1 of the red light 111 is less than the following angles: Figure 4 The incident angle θ3 of the infrared light 121 shown in B, Figure 5 The incident angle θ4 of the green light 131 shown in A and Figure 5 B shows the incident angle θ5 of the blue light 141 .

[0051] Therefore, Figure 4 The relative position relationship of the red light illumination 11 with respect to the line scan camera 15 shown in A makes it easier to adjust the setting angle of the red light illumination 11 and the line scan camera 15, and can make the specular reflection light of the infrared light 121 more reliable or easy to enter the line scan camera 15. In addition, since the relationship between θ1 and Figure 5 θ4 shown in A and Figure 5 The difference in θ5 shown in B can more reliably separate diffusely reflected light from illumination other than the red light 11 and specularly reflected light from the red light 11 and allow them to enter the line scan camera 15. In this embodiment, both θ1 and θ2 can be close to 7 degrees.

[0052] Furthermore, the signal intensity adjustment unit 162 can be used to adjust the line scan camera 15 so that the signal intensity obtained based on the specularly reflected light of the red light 111 is reduced to less than 1%. Typically, the signal intensity obtained based on specularly reflected light is higher than the signal intensity obtained based on diffusely reflected light. Therefore, if the line scan camera 15 is not adjusted as described above, the signal intensity obtained by the line scan camera 15 may exceed the permissible value due to the red light illumination 11 set at an incident angle of θ1 so that the specularly reflected light of the red light 111 enters the line scan camera 15. Alternatively, the signal intensity obtained by the line scan camera 15 may be affected by the intensity of inspection light from other illumination sources besides the red light illumination 11, making it impossible to obtain appropriate images. Therefore, setting a limit to reduce the signal intensity to less than 1% can eliminate this problem.

[0053] Figure 4 B shows the outline of the relative position of the infrared light illuminator 12 with respect to the line scan camera 15. Figure 4 In B, the infrared light 121 is reflected in all directions as diffuse reflection light by the surface of the electrode material 2, and the line scan camera 15 receives a part of the diffuse reflection light. Figure 3 A and Figure 3As described in FIG. 3 , defects 3 and foreign matter in the coating 22 can be easily detected in the infrared image. Moreover, by making the irradiation intensity of the infrared light 121 the highest among all the irradiation intensities of the inspection light, this effect can be achieved more reliably. In addition, in this embodiment, θ3 can also take a value close to 17. And, Figure 4 θ3 shown in B is larger than the reflection angle of the diffusely reflected light incident on the line camera 15 , but the magnitude relationship may be reversed.

[0054] Figure 5 A shows the outline of the relative position of the green light illumination 13 with respect to the line scan camera 15. Figure 5 In A, it is assumed that a convex defect 3 is generated on the surface of the electrode material 2 (more precisely, the aluminum foil 21), and the green light 131 is irradiated onto the defect 3. The line scan camera 15 sometimes receives a portion of the specularly reflected light of the green light 131 irradiated onto the defect 3. Figure 4 When the red light 111 at the position shown in A is similarly irradiated to the defect 3 with red light 111, the mirror-reflected light thereof will not enter the line scan camera 15. Figure 5 B shows the relative position of the blue light illumination 14 with respect to the line scan camera 15. Figure 5 A is the same, so the description is omitted. In summary, in RGB images, sometimes it is equivalent to Figure 5 The left side of the defect 3 in the direction shown in A is displayed in green, which is sometimes equivalent to Figure 5 B (can also be Figure 5 The portion to the right of the defect 3 in the direction shown in A) is displayed in blue. In contrast, the portion of the surface of the electrode material 2 corresponding to the smooth area where the defect 3 does not occur is easily displayed in red. Therefore, the defect 3 can be more easily identified. In addition, in this embodiment, both θ4 and θ5 can take values ​​close to 70 degrees. In addition, Figure 5 θ4 and Figure 5 θ5 shown in B is larger than the reflection angle of the diffusely reflected light incident on the line camera 15 , but the magnitude relationship between them may be reversed.

[0055] In summary, the inspection device 1 of this embodiment is configured so that the incident angle of red light 111 is the smallest among all the inspection light incident angles. Furthermore, the reflected light of red light 111 is separated as specular reflection light from the other diffuse reflection light. This allows for easy detection of the boundary between aluminum foil 21 and coating 22 in the R image, and allows for the red display of smooth areas of aluminum foil 21 free of defects 3 or foreign matter in the RGB image, distinguishable from other areas. Furthermore, the infrared light 12 is configured so that the diffuse reflection of infrared light 121 is incident on the line scan camera 15, resulting in the highest irradiation intensity of infrared light 121 among all the inspection light sources. This enables more reliable detection of defects 3 and foreign matter in coating 22. Furthermore, by providing the green light illumination 13 and the blue light illumination 14 so that the diffusely reflected light of the green light 131 and the blue light 141 enters the line camera 15 , the defects 3 and foreign matter in the aluminum foil 21 and their shapes can be easily detected.

[0056] Furthermore, the inspection apparatus 1 of this embodiment may also include a display unit 17 such as a monitor. Figure 6 An example of the display content on the display unit 17 is schematically shown in FIG. Figure 6 The portion enclosed by the dotted line x shows a map that represents the distribution of defects 3 and foreign matter on the surface of the electrode material 2 using dots. This allows the user to instantly understand, for example, which portion of the surface of the electrode material 2 is prone to defects 3 and foreign matter. Furthermore, the portion enclosed by the dotted line y displays enlarged images of the defects 3 and foreign matter corresponding to the map, allowing the user to easily understand the shapes of the defects 3 and foreign matter. Furthermore, in this embodiment, a thumbnail image of the actual inspection can be displayed in the portion enclosed by the dotted line z. In addition, this image shows the locations of the defects 3 and foreign matter, as well as information related to the size and positional deviation of the coating 22.

[0057] <Note 1>

[0058] An inspection device 1 that inspects the quality of an electrode material 2 for a battery by an optical method, characterized in that the inspection device 1 comprises: a plurality of illuminations 11, 12, 13, and 14 that irradiate inspection light 111, 121, 131, and 141 onto the surface of the electrode material; and a photographing unit 15 that respectively receives reflected light of the inspection light irradiated from the plurality of illuminations and reflected by the surface of the electrode material, and photographs the surface of the electrode material, the plurality of illuminations including a first illumination 11, the incident angle of the first illumination being set so that the specular reflected light of the irradiated inspection light reflected by the surface of the electrode material is incident on the photographing unit, and the inspection device 1 further comprises adjustment units 161 and 162 that adjust or set specified conditions in the following manner: so that in the photographing unit, the signal intensity obtained based on the reflected light of the inspection light 111 irradiated from the first illumination among the plurality of illuminations and reflected by the surface of the electrode material is selectively reduced.

[0059] <Note 2>

[0060] An inspection device 1 for inspecting the quality of an electrode material 2 for a battery by an optical method, characterized in that the inspection device 1 comprises: a plurality of lightings 11, 12, 13, 14, which irradiate inspection light 111, 121, 131, 141 onto the surface of the electrode material; and a photographing unit 15, which receives reflected light of the inspection light irradiated by the plurality of lightings and reflected by the surface of the electrode material, and photographs the surface of the electrode material, wherein the plurality of lightings includes a first lighting 11, the incident angle of the first lighting being set so that the inspection light The mirror-reflected light of the inspection light irradiated by the surface of the electrode material is incident on the shooting part, and the boundary between the coating 22 and the metal sheet 21 is detected by the reflected light of the inspection light 111 irradiated from the first illumination, thereby measuring the size of the coating, and the reflected light of the inspection light 121, 131, 141 irradiated by the surface of the electrode material from the illumination 12, 13, 14 other than the first illumination among the multiple illuminations is detected, so that the defect 3 or foreign matter of the coating or the metal sheet can be detected.

[0061] Label Description

[0062] 1Inspection device

[0063] 11 Red light illumination

[0064] 111 red light

[0065] 12 Infrared lighting

[0066] 121 infrared light

[0067] 13 Green Light Illumination

[0068] 131 green light

[0069] 14 Blue light illumination

[0070] 141 blue light

[0071] 15 line scan cameras

[0072] 161 light intensity adjustment unit

[0073] 162 signal strength adjustment unit

[0074] 17 Display unit

[0075] 2Electrode material

[0076] 21 aluminum foil

[0077] 22 coating

[0078] 3 Defects

Claims

1. An inspection device for inspecting the quality of a battery electrode material by an optical method, characterized in that: The inspection device comprises: a plurality of lighting devices for irradiating inspection light onto the surface of the electrode material; and an imaging unit that receives reflected light of the inspection light irradiated from the plurality of illumination sources and reflected from the surface of the electrode material, and images the surface of the electrode material; The plurality of illuminations include a first illumination whose incident angle is set so that specularly reflected light of the irradiated inspection light reflected from the surface of the electrode material is incident on the imaging unit. The inspection device further includes an adjustment unit that adjusts or sets a predetermined condition so that, in the imaging unit, signal intensity obtained by reflected light reflected from the surface of the electrode material based on the inspection light irradiated from the first illumination among the plurality of illuminations is selectively reduced.

2. The inspection device according to claim 1, characterized in that The plurality of illuminations include a second illumination that emits inspection light having a wavelength and an incident angle different from those of the first illumination. The imaging unit receives the inspection light emitted from the first illumination and reflected from the surface of the electrode material, and the inspection light emitted from the second illumination and reflected from the surface of the electrode material, respectively. The inspection device acquires a captured image capable of discriminating the uneven shape of the surface of the electrode material based on the difference in color.

3. The inspection device according to claim 1, characterized in that The predetermined condition is the intensity of the inspection light emitted from the first illumination or the sensitivity of the imaging unit to the reflected light of the inspection light emitted from the first illumination that is reflected from the surface of the electrode material.

4. The inspection device according to claim 1, wherein: The adjustment unit reduces the signal intensity obtained based on the reflected light of the inspection light emitted from the first illumination and reflected from the surface of the electrode material to 1 percent or less.

5. The inspection device according to claim 1, wherein: The plurality of illuminations include infrared light illumination for irradiating infrared light as the inspection light, The infrared light illumination irradiates inspection light at the highest irradiation intensity among the plurality of illuminations.

6. The inspection device according to claim 1, characterized in that The incident angles of the inspection lights from the plurality of illumination sources are different, An absolute value of an incident angle of the inspection light from the first illumination is smallest among incident angles of the inspection light from the plurality of illuminations.

7. The inspection device according to claim 1, characterized in that The electrode material for the battery is formed by coating a metal sheet with an active material.

8. The inspection device according to claim 7, characterized in that The boundary between the coating material and the metal sheet can be detected by the reflected light of the inspection light irradiated from the first illumination. By detecting the boundary between the applied object and the metal sheet, the size of the applied object can be measured.

9. The inspection device according to claim 5, characterized in that The plurality of illuminations further include illumination for emitting red light, illumination for emitting blue light, and illumination for emitting green light.

10. An inspection device for inspecting the quality of a battery electrode material by an optical method, characterized in that: The inspection device comprises: a plurality of lighting devices for irradiating inspection light onto the surface of the electrode material; and an imaging unit that receives reflected light of the inspection light irradiated from the plurality of illumination sources and reflected from the surface of the electrode material, and images the surface of the electrode material; The plurality of illuminations include a first illumination whose incident angle is set so that specularly reflected light of the irradiated inspection light reflected from the surface of the electrode material is incident on the imaging unit. By detecting the boundary between the coating and the metal sheet by the reflected light of the inspection light irradiated from the first illumination, the size of the coating can be measured. Defects or foreign matter in the coating or the metal sheet can be detected by light reflected from the surface of the electrode material of the inspection light irradiated from illumination other than the first illumination among the plurality of illuminations.

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