Solar cell module inspection equipment
The inspection device uses illumination light with a wavelength between 380 nm and 430 nm, inclined relative to the imaging axis, to enhance contrast and detect foreign objects like hair in solar cell modules, addressing the challenge of light absorption and reflection by the sealing glass.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- KANEKA CORP
- Filing Date
- 2024-11-06
- Publication Date
- 2026-05-19
AI Technical Summary
Conventional inspection devices struggle to detect hair or similar foreign matter between the sealing glass and solar cell in solar cell modules due to light absorption and total reflection by the sealing glass, making it difficult to differentiate between the solar cell and hair, especially under natural light conditions.
An inspection device that uses illumination light with a maximum peak wavelength between 380 nm and 430 nm, inclined relative to the imaging axis, to minimize light absorption and reflection by the sealing glass, enhancing the contrast between the solar cell and foreign objects like hair.
The device effectively detects foreign objects, such as hair, by creating a visible contrast difference with the solar cell, even when they share similar colors, thereby improving the detection accuracy and reliability of solar cell module inspection.
Smart Images
Figure 2026081916000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an inspection device for a solar cell module.
Background Art
[0002] Conventionally, a solar cell module in which a solar cell is sealed between two sealing glasses has been known (for example, Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] By the way, in the manufacturing process of a solar cell module, when an operator assembles the solar cell module, there may be a case where hair gets mixed between the sealing glass and the solar cell. When hair gets mixed between the sealing glass and the solar cell, depending on the viewing angle of the solar cell module, the hair part may appear to protrude on the solar cell, or the hair may catch fire between the sealing glass and the solar cell during power generation, and there is a problem that it gets scorched in the shape of the hair. Therefore, it is desirable to confirm the mixing of hair between the solar cell and the sealing glass after assembling the solar cell module. However, since the power generation part of the solar cell and the hair are of a similar color, in a photographed image taken under natural light, the solar cell and the hair are almost the same color, and there is a problem that the presence or absence of hair cannot be confirmed.
[0005] There is a conventional visual inspection device for detecting hair, which is described in Patent Document 2. Patent Document 2 discloses a visual inspection device that detects hair by using coaxial illumination and taking images with ultraviolet light as the illumination source. However, since the inspection surface of a solar cell module is made of sealing glass, there is a problem that the light is absorbed by the sealing glass when ultraviolet light of 380 nm or less is irradiated as in Patent Document 2, and when taking images using coaxial illumination as in Patent Document 2, the light is totally reflected at the surface of the sealing glass. As a result, the amount of light that reaches the solar cell side of the sealing glass is small, and there is a problem that foreign matter between the sealing glass and the solar cell cannot be detected.
[0006] Therefore, the object of the present invention is to provide an inspection device for solar cell modules that is the same color as or similar to the majority of the solar cell and can detect foreign matter that has entered between the solar cell and the sealing glass. [Means for solving the problem]
[0007] One aspect of the present invention for solving the above-mentioned problems is an inspection device for a solar cell module comprising a sealing glass, a sealing member, and a solar cell sandwiched between the sealing glass and the sealing member, wherein the device detects a foreign object having the same or similar color as most of the solar cell between the sealing glass and the solar cell, the device comprising: an imaging unit; an illumination unit that irradiates the solar cell with illumination light having a maximum peak in the wavelength range of over 380 nm and up to 430 nm, at least through the sealing glass, toward the irradiated portion of the solar cell from a direction inclined with respect to the imaging axis of the imaging unit; and a foreign object detection unit that detects the foreign object based on image data generated by the imaging unit after receiving the reflected light from the irradiated portion, wherein the solar cell has a reflectance of 5% or more of the illumination light and a reflectance greater than that of the foreign object.
[0008] In this context, "approximate colors" refers to colors that, when photographed under sunlight (natural light) using a digital camera or similar means, have a difference of 20 or less when the colors of the captured image are classified into the 256 gradations of each RGB channel.
[0009] According to this configuration, the illumination unit irradiates the solar cell with light having a maximum peak in the wavelength range of over 380 nm and up to 430 nm, at least through the sealing glass, from a direction inclined with respect to the imaging axis of the imaging unit. Therefore, compared to conventional methods, absorption of the irradiated light by the sealing glass is suppressed, while also suppressing total internal reflection by the sealing glass. According to this aspect, solar cells have a reflectivity of 5% or more for irradiated light with a maximum peak in the wavelength range of over 380 nm and up to 430 nm, and their reflectivity is greater than that of foreign objects. Therefore, a difference can be created between the solar cell and the foreign object in the captured image data, making it easier to detect the foreign object even if it is the same color as or similar to the majority of the solar cell. Thus, according to this aspect, it is possible to detect foreign matter that is the same color as or similar to the majority of the solar cell and has entered between the solar cell and the sealing glass.
[0010] A preferred configuration is that the illumination unit irradiates the illumination light at an inclination angle of more than 0 degrees and less than or equal to 45 degrees with respect to the imaging axis of the imaging unit.
[0011] A preferred feature is that the foreign matter consists mostly of hair that is black or a color close to black.
[0012] A preferred configuration is that the irradiated light has a wavelength of 430 nm or less.
[0013] A preferred configuration is that the irradiated light has a wavelength exceeding 380 nm.
[0014] A preferred configuration is that the irradiated light has its maximum peak in the wavelength range of 400 nm to 410 nm.
[0015] A preferred configuration is that the foreign object detection unit identifies the portion of the foreign object in the captured image based on the difference in contrast between the solar cell and the foreign object.
[0016] A preferred aspect is that the sealing glass is a curved substrate having a three-dimensionally extended curved surface.
[0017] A preferred aspect is that a detection operation for detecting a second foreign object different from the foreign object can be executed. The detection operation irradiates light having a wavelength exceeding 430 nm toward the irradiated portion, images using the reflected light of the irradiated light at the irradiated portion, and detects a second foreign object from the captured image.
[0018] As long as the above-described aspects are included in the technical scope of the present invention, they can be made subordinate to each other, a part of the configuration can be cited, or a part of the configuration can be replaced between the aspects.
Effect of the Invention
[0019] According to the inspection apparatus of the present invention, it is possible to detect a foreign object that has entered between the solar cell and the sealing glass and has a color that is the same as or similar to most of the solar cell.
Brief Description of the Drawings
[0020] [Figure 1] It is an explanatory diagram of an inspection apparatus according to a first embodiment of the present invention. (a) is a configuration diagram of the inspection apparatus, and (b) is a side view conceptually showing the inspection apparatus. [Figure 2] It is a cross-sectional view of a solar cell module to be inspected by the inspection apparatus of FIG. 1, and hatching is omitted for easy understanding. [Figure 3] It is a captured image when irradiated light is irradiated from each illumination unit to the solar cell module in the inspection apparatus of FIG. 1. (a) is a captured image when irradiated with irradiated light having a wavelength of 405 nm, (b) is a captured image when irradiated with irradiated light having a wavelength of 467 nm, and (c) is a captured image when irradiated with irradiated light having a wavelength of 860 nm.
Modes for Carrying Out the Invention
[0021] Hereinafter, embodiments of the present invention will be described in detail.
[0022] The inspection apparatus 1 of the first embodiment of the present invention, as shown in Figure 1(a), comprises a shooting device 2 and an image processing device 3. The image processing device 3 performs image processing based on the image captured by the shooting device 2 to detect foreign matter 200 that has entered the inside of the solar cell module 100.
[0023] <Photography device 2> As shown in Figure 1(b), the imaging device 2 comprises an imaging unit 10, a first illumination unit 11, a second illumination unit 12, and a mounting unit 13.
[0024] (Imaging unit 10) The imaging unit 10 has a photodetector that detects the intensity of light and converts the intensity of light into an electrical signal. As shown in Figure 1(b), it is the part that generates imaging image data including an electrical signal obtained by receiving and converting the reflected light from the illuminated portion 101 of the solar cell module 100, which is irradiated from the illumination units 11 and 12, by the photodetector.
[0025] <Lighting section 11, 12> As shown in Figure 1(b), the lighting units 11 and 12 are lighting devices capable of irradiating the irradiated portion 101 of the solar cell module 100 with irradiation light L1 and L2. The lighting units 11 and 12 are capable of emitting linear illumination light L1 and L2 that extends in a direction intersecting (orthogonal in this embodiment) the direction of movement T1 of the mounting unit 13. That is, the illuminated portion 101 of the solar cell module 100, which is illuminated by the lighting units 11 and 12, extends in a linear shape in a direction intersecting (orthogonal in this embodiment) the direction of movement T1 of the mounting unit 13.
[0026] The first illumination unit 11 is located upstream of the imaging axis L3 of the imaging unit 10 in the movement direction T1 of the mounting unit 13, and is capable of irradiating illumination light L1 from a direction inclined with respect to the imaging axis L3 of the imaging unit 10. As shown in Figure 1(b), the first illumination unit 11 is inclined at an angle θ1 upstream of the movement direction T1 with respect to the imaging axis L3 of the imaging unit 10 when viewed from the extending direction of the illuminated unit 101. From the viewpoint of receiving reflected light from the illuminated area 101 with the imaging unit 10, the tilt angle θ1 is preferably greater than 0 degrees and 60 degrees or less, and more preferably 45 degrees or less.
[0027] The second illumination unit 12 is located downstream of the imaging axis L3 of the imaging unit 10 in the movement direction T1, and is capable of illuminating with illumination light L2 from a direction inclined with respect to the imaging axis L3 of the imaging unit 10. The second illumination unit 12 is located downstream of the first illumination unit 11 in the movement direction T1. As shown in Figure 1(b), the second illumination unit 12 is inclined at an angle θ2 downstream of the imaging axis L3 of the imaging unit 10 in the movement direction T1 when viewed from the extending direction of the illuminated unit 101. From the viewpoint of enabling the imaging unit 10 to receive reflected light from the irradiated unit 101, the tilt angle θ2 is preferably greater than 0 degrees and 60 degrees or less, and more preferably 45 degrees or less. The inclination angle θ2 is preferably the same as the inclination angle θ1 of the first illumination unit 11.
[0028] The illumination units 11 and 12 are capable of irradiating with illumination light L1 and L2 having a maximum peak in the wavelength range of over 380 nm and up to 430 nm, preferably with illumination light L1 and L2 having a maximum peak in the wavelength range of 420 nm or less, and more preferably with illumination light L1 and L2 having a maximum peak in the wavelength range of 400 nm to 410 nm. Preferably, the illumination units 11 and 12 are cut off at wavelengths exceeding 430 nm by a filter, so that they can emit illumination light L1 and L2 having spectral intensity only at wavelengths of 430 nm or less. In other words, it is preferable that the illumination light L1 and L2 emitted from the illumination units 11 and 12 is visible light and is violet light. Furthermore, it is preferable that the illumination units 11 and 12 are cut off at wavelengths of 380 nm or less by a filter, and that they are capable of emitting illumination light L1 and L2 having spectral intensity only at wavelengths exceeding 380 nm. In this embodiment, both illumination units 11 and 12 use illumination light L1 and L2 with a wavelength of 405 nm.
[0029] The lighting units 11 and 12 are not particularly limited as long as they function as light sources, but for example, LEDs and organic ELs can be used. The lighting units 11 and 12 of this embodiment have multiple directional LEDs, and these LEDs are arranged in the direction of extension of the illuminated area 101.
[0030] (Mounting section 13) The mounting section 13 is a stage on which the solar cell module 100 is mounted, as shown in Figure 1(b), and is movable in the movement direction T1 with respect to the imaging axis L3 of the imaging section 10. In other words, the imaging device 2 moves with the mounting unit 13 mounted so that the light-receiving surface 110, which is the surface to be inspected on the solar cell module 100, faces the imaging unit 10, thereby enabling imaging of the entire inspection target portion of the light-receiving surface 110.
[0031] <Image processing device 3> The image processing device 3 is a computer with a hardware configuration consisting of a central processing unit comprising a control unit that controls each device and an arithmetic unit that performs calculations on the data, a storage device for storing data, an input device for receiving data from the outside, and an output device for outputting data to the outside. As shown in Figure 1(a), the image processing device 3 includes an image acquisition unit 20, a foreign object detection unit 21, and a determination unit 22.
[0032] (Image acquisition unit 20) The image acquisition unit 20 is the part that acquires the image data generated by the imaging unit 10 from the imaging unit 10.
[0033] (Foreign object detection unit 21) The foreign object detection unit 21 is the part that generates an image based on the image capture data acquired by the image acquisition unit 20 and detects foreign objects 200 in the image. Specifically, the foreign object detection unit 21 generates a grayscale image based on the image capture data acquired by the image acquisition unit 20, and can identify the portion of the foreign object 200 in the image based on the difference in contrast between the solar cell 150 and the foreign object 200 in the image.
[0034] (Judgment section 22) The determination unit 22 is a part that determines whether the solar cell module 100 is good or bad based on at least one selected from the group of area, shape, and position of the foreign object 200 detected by the foreign object detection unit 21. In this embodiment, the determination unit 22 determines whether the solar cell module 100 is good or bad based on the area of the foreign object 200 detected by the foreign object detection unit 21.
[0035] <Solar cell module 100> As shown in Figure 2, the solar cell module 100 has a light-receiving surface 110 and a back surface 111, and is three-dimensionally curved so that the light-receiving surface 110 is outward relative to the back surface 111, making it a curved module with curvature. The solar cell module 100 is sealed by sandwiching the solar cell string 122 between a light-receiving sealing member 120 and a back-side sealing member 121.
[0036] (Light receiving side sealing member 120) As shown in Figure 2, the light-receiving side sealing member 120 covers the light-receiving surface 110 side of the solar cell string 122, and comprises a light-receiving side sealing glass 130 and a light-receiving side sealing material 131 in order from the light-receiving surface 110 side toward the solar cell string 122 side.
[0037] The light-receiving side sealing glass 130 is a light-transmitting insulating substrate having sealing, insulating, and light-transmitting properties, and is a component that constitutes the light-receiving surface 110. The light-receiving side sealing glass 130 is a curved substrate in which the light-receiving surface 110 is a three-dimensionally extended curved surface, and thus has curvature. The light-receiving sealing glass 130 can be made of a glass substrate such as float glass or colored glass.
[0038] The light-receiving side sealing material 131 is a light-transmitting insulating sealing material that has sealing, insulating, and light-transmitting properties, and is an adhesive that bonds the solar cell string 122 and the light-receiving side sealing glass 130. The light-receiving side encapsulant 131 is not particularly limited as long as it has sealing, insulating, and light-transmitting properties; for example, a resin encapsulant such as polyolefin elastomer can be used.
[0039] (Back side sealing member 121) As shown in Figure 1, the back sealing member 121 covers the back surface 111 side of the solar cell string 122, and comprises a back sealing substrate 140 and a back sealing material 141 in order from the back surface 111 side toward the solar cell string 122 side.
[0040] The back side sealing substrate 140 is an insulating substrate having sealing and insulating properties, and is a component that constitutes the back surface 111. The back-side sealing substrate 140 is a curved substrate that curves in the same direction as the light-receiving side sealing glass 130, and the distance between it and the light-receiving side sealing glass 130 is constant. The back sealing substrate 140 can be, for example, a glass substrate such as float glass or colored glass, or a resin substrate such as a back sheet.
[0041] The back side sealing material 141 is a light-transmitting insulating sealing material that has sealing, insulating, and light-transmitting properties, and is an adhesive that bonds the solar cell string 122 to the back side sealing substrate 140. The back sealing material 141 is not particularly limited as long as it has sealing, insulating, and light-transmitting properties; for example, a resin sealing material such as polyolefin elastomer can be used.
[0042] (Solar cell string 122) The solar cell string 122 consists of multiple solar cells 150 connected in series via a conductive adhesive 151. The solar cell 150 has a reflectance of 5% or more for irradiated light L1 and L2 in the wavelength range of over 380 nm and up to 430 nm at the irradiated part 101, and its reflectance is greater than that of the foreign matter 200. The solar cell 150 has a reflectance of less than 5% for irradiated light L1 and L2 in the wavelength range of 460 nm or more at the irradiated part 101, and the absolute value of the difference between this and the reflectance of the foreign matter 200 is 2% or less. Solar cell 150 is a black solar cell, meaning it has a black appearance.
[0043] <Foreign object 200> The foreign matter 200 is the same color as or similar to the majority of the solar cell 150, and is in the form of a thin thread. The foreign matter 200 is one in which, when photographed with a digital camera or other photographic means under sunlight (natural light), the difference in the color of the captured image is 20 levels or less when the color of each of the 256 RGB levels is classified, and preferably 10 levels or less. In this embodiment, the foreign object 200 is hair, specifically black hair. That is, the foreign object 200 has a curved outer surface with fine irregularities formed on it. The foreign matter 200 detected by the inspection device 1 of this embodiment includes foreign matter 200a located at the interface between the solar cell 150 and the light-receiving side sealing material 131, and foreign matter 200b located at the interface between the light-receiving side sealing material 131 and the light-receiving side sealing glass 130. In other words, the foreign matter 200 is located between the solar cell 150 and the light-receiving side sealing glass 130.
[0044] Next, a method for detecting foreign matter 200 using the inspection device 1 of this embodiment will be described.
[0045] In the detection method of the inspection device 1, first, the solar cell module 100 is placed on the mounting section 13 so that the light-receiving surface 110 is convex, and while irradiating the irradiated portion 101 of the solar cell module 100 placed on the mounting section 13 with irradiation light L1 and L2 from the first illumination section 11 and the second illumination section 12, the mounting section 13 is moved so that the irradiation light L1 and L2 passes through the entire inspection target portion of the light-receiving surface 110 of the solar cell module 100.
[0046] At this time, the imaging unit 10 receives the reflected light of the illumination light L1 and L2 passing along the imaging axis L3, and the imaging unit 10 generates image data. Furthermore, the image processing device 3 acquires image data generated by the imaging unit 10 from the image acquisition unit 20, generates an image based on the acquired image data in the foreign object detection unit 21, identifies the foreign object 200 in the image based on the difference in contrast between the foreign object 200 and the solar cell 150 in the image, and the determination unit 22 determines whether the solar cell module 100 is good or bad based on the area of the foreign object 200 detected by the foreign object detection unit 21. Specifically, the foreign object detection unit 21 generates a grayscale image based on the image data it acquires. Since the reflectivity of the foreign object 200 is lower than that of the solar cell 150, the foreign object 200 appears darker (more luminous) than the solar cell 150. The difference in luminosity allows the unit 22 to identify the outline of the foreign object 200 in the image. The determination unit 22 then determines that the solar cell module 100 is a good product if the area of the foreign object 200 identified by the foreign object detection unit 21 across the entire inspection target area of the light-receiving surface 110 of the solar cell module 100 is less than or equal to a predetermined area. If the area of the foreign object 200 identified by the foreign object detection unit 21 exceeds the predetermined area, the determination unit 22 determines that the solar cell module 100 is a defective product.
[0047] Next, we will describe the images captured by the inspection device 1 of this embodiment.
[0048] Figure 3(a) shows the image captured when the irradiated area 101 is irradiated with illumination light L1 and L2 with a wavelength of 405 nm from the illumination units 11 and 12 in the inspection device 1. Figure 3(b) shows the image captured when the irradiated area 101 is irradiated with illumination light L1 and L2 with a wavelength of 467 nm from the illumination units 11 and 12 in the inspection device 1. Figure 3(c) shows the image captured when the irradiated area 101 is irradiated with illumination light L1 and L2 with a wavelength of 860 nm from the illumination units 11 and 12 in the inspection device 1. In Figures 3(b) and 3(c), where irradiation was performed with light sources L1 and L2 having their maximum peak in the range of 460 nm or higher, there was almost no contrast difference between the foreign object 200 (hair) and the solar cell 150, and the foreign object 200 and the solar cell 150 appeared to be almost the same color, making it difficult to identify the foreign object 200. In contrast, in Figure 3(a), where irradiation was performed with light sources L1 and L2 having their maximum peak in the range of wavelengths between 380 nm and 430 nm, the difference in density between the foreign object 200 (hair) and the solar cell 150 was clearly visible, making it possible to identify the foreign object 200.
[0049] According to the inspection apparatus 1 of this embodiment, the apparatus includes an imaging unit 10, illumination units 11 and 12 that irradiate the irradiated portion 101 of the solar cell 150 with irradiation light L1 and L2 having a maximum peak in the wavelength range of over 380 nm and up to 430 nm, from a direction inclined with respect to the imaging axis L3 of the imaging unit 10, at least through the light-receiving side sealing glass 130, and a foreign object detection unit 21 that detects foreign objects 200 based on the image data generated by the imaging unit 10 after receiving the reflected light from the irradiated portion 101, wherein the solar cell 150 has a reflectance of 5% or more for the irradiation light L1 and L2, and a reflectance greater than that of the foreign object 200. In other words, the illumination units 11 and 12 irradiate the irradiated portion 101 of the solar cell 150 with illumination light L1 and L2 having a maximum peak in the wavelength range of over 380 nm and up to 430 nm, at least through the light-receiving sealing glass 130, from a direction inclined with respect to the imaging axis L3 of the imaging unit 10. This suppresses absorption of the illumination light L1 and L2 by the light-receiving sealing glass 130 while also suppressing total internal reflection by the light-receiving sealing glass 130. Furthermore, the solar cell 150 has a reflectance of 5% or more for irradiated light L1 and L2, which have their maximum peak in the wavelength range of over 380 nm and up to 430 nm, and its reflectance is greater than that of the foreign object 200. Therefore, a contrast difference can be generated between the solar cell 150 and the foreign object 200, making it easier to detect the outline of the foreign object 200 even if the foreign object 200 is the same color as or similar to most of the solar cell 150. Thus, according to the inspection device 1 of this embodiment, it is possible to detect foreign matter 200 that is the same color as or similar to the majority of the solar cell 150 and has entered between the solar cell 150 and the light-receiving side sealing glass 130.
[0050] In the inspection apparatus 1 of this embodiment, it is preferable that the illumination units 11 and 12 irradiate the imaging unit 10 with illumination light L1 and L2 at inclination angles θ1 and θ2 of 45 degrees or more relative to the imaging axis L3. By doing so, the amount of light from the diffuse reflection component in the direction of the imaging axis L3 is increased, which increases the contrast difference between the foreign object 200 and the solar cell 150 in the captured image, making it easier to detect the foreign object 200.
[0051] According to the inspection device 1 of this embodiment, it is preferable that the foreign matter 200 is mostly black or a hair of a color close to black. This device can be used more favorably in this case.
[0052] In the inspection apparatus 1 of this embodiment, it is preferable that the irradiated light L1 and L2 have a wavelength of 430 nm or less. This increases the contrast difference between the foreign matter 200 and the solar cell 150, making it easier to detect the foreign matter 200.
[0053] In the inspection apparatus 1 of this embodiment, it is preferable that the irradiated light L1 and L2 have wavelengths exceeding 380 nm. This suppresses absorption by the light-receiving sealing glass 130, making it easier to detect foreign matter 200.
[0054] In the inspection apparatus 1 of this embodiment, it is preferable that the irradiation light L1 and L2 have their maximum peak in the wavelength range of 400 nm to 410 nm. This makes it easier to detect foreign matter 200.
[0055] In the inspection device 1 of this embodiment, it is preferable that the foreign object detection unit 21 identifies the portion of the foreign object 200 in the captured image based on the difference in contrast between the solar cell 150 and the foreign object 200. This makes it easier to visually recognize the position and extent of the foreign object 200 from the captured image.
[0056] According to the inspection apparatus 1 of this embodiment, the light-receiving sealing glass 130 is preferably a curved substrate having a three-dimensionally extended curved surface. This apparatus can be used more favorably in such cases.
[0057] As an application example of the above-described embodiment, the inspection device 1 may be capable of performing a detection operation to detect a second foreign object different from the foreign object 200. In this detection operation, it is preferable to irradiate the irradiated area 101 with light having a wavelength exceeding 430 nm, take an image using the reflected light from the irradiated area 101, and detect the second foreign object from the captured image.
[0058] In the embodiments described above, the solar cell module 100 had a convex surface with the light-receiving surface 110 facing outward relative to the back surface 111, but the present invention is not limited thereto. The solar cell module 100 may also have a concave surface with the light-receiving surface 110 facing inward relative to the back surface 111. In the embodiments described above, the solar cell module 100 was a curved solar cell module with a curved shape, but the present invention is not limited thereto. The solar cell module 100 may also be a solar cell module that extends in a flat shape.
[0059] In the embodiment described above, there were two illumination units 11 and 12, but the present invention is not limited thereto. There may be one illumination unit, or there may be three or more illumination units.
[0060] In the embodiment described above, the illumination units 11 and 12 had the same inclination angles θ1 and θ2 with respect to the imaging axis L3, and were symmetrical with respect to the imaging axis L3 when viewed from the side. However, the present invention is not limited to this. The illumination units 11 and 12 may have different inclination angles θ1 and θ2.
[0061] In the embodiment described above, the foreign object detection unit 21 generates a grayscale image based on the image capture data acquired by the image capture unit 20, but the present invention is not limited thereto. The foreign object detection unit 21 may also generate a color image based on the image capture data acquired by the image capture unit 20. In this case, the portion of the foreign object 200 in the image is identified based on the difference in contrast between the solar cell 150 and the foreign object 200, using the color image.
[0062] In the above-described embodiment, the determination unit 22 determined the quality of the solar cell module 100 based on the area of the foreign object 200 detected by the foreign object detection unit 21, but the present invention is not limited thereto. The determination unit 22 may also determine the quality based on the shape or position of the foreign object 200 detected by the foreign object detection unit 21.
[0063] In the embodiments described above, the components can be freely substituted or added between each embodiment, as long as they fall within the technical scope of the present invention. [Explanation of Symbols]
[0064] 1. Inspection device 10 Imaging Unit 11. First Lighting Section 12. Second Lighting Section 21 Foreign object detection unit 100 solar modules 101 Irradiated area 121 Rear side sealing member (sealing member) 130 Light-receiving side sealing glass (sealing glass) 150 solar cells 200,200a,200b Foreign matter
Claims
1. A solar cell module comprising a sealing glass, a sealing member, and solar cells sandwiched between the sealing glass and the sealing member, wherein an inspection device for a solar cell module is used to detect foreign matter having the same or similar color as most of the solar cells between the sealing glass and the solar cells, Imaging unit, An illumination unit that irradiates the solar cell with illumination light having a maximum peak in the wavelength range of over 380 nm and up to 430 nm, from a direction inclined with respect to the imaging axis of the imaging unit, at least through the sealing glass, toward the irradiated portion of the solar cell, The system includes a foreign object detection unit that detects the foreign object based on the image data generated by the imaging unit after receiving reflected light from the irradiated area, The solar cell is an inspection device for solar cell modules, wherein the reflectance of the irradiated light is 5% or more and is greater than that of the foreign matter.
2. The inspection apparatus for a solar cell module according to claim 1, wherein the illumination unit irradiates the illumination light at an inclination angle of more than 0 degrees and 45 degrees or less with respect to the imaging axis of the imaging unit.
3. The inspection apparatus for solar cell modules according to claim 1 or 2, wherein the foreign matter is mostly black or a color close to black.
4. The inspection apparatus for a solar cell module according to claim 1 or 2, wherein the irradiating light has a wavelength of 430 nm or less.
5. The inspection apparatus for a solar cell module according to claim 1 or 2, wherein the irradiating light has a wavelength exceeding 380 nm.
6. The inspection apparatus for a solar cell module according to claim 1 or 2, wherein the irradiated light has a maximum peak in the wavelength range of 400 nm to 410 nm.
7. The inspection apparatus for a solar cell module according to claim 1 or 2, wherein the foreign object detection unit identifies the portion of the foreign object in the captured image based on the difference in contrast between the solar cell and the foreign object.
8. The inspection apparatus for a solar cell module according to claim 1 or 2, wherein the sealing glass is a curved substrate having a three-dimensionally extended curved surface.
9. A detection operation can be performed to detect a second foreign object that is different from the aforementioned foreign object. The inspection apparatus for a solar cell module according to claim 1 or 2, wherein the detection operation involves irradiating the irradiated area with light having a wavelength exceeding 430 nm, taking an image using the reflected light from the irradiated area, and detecting a second foreign object from the captured image.