Inspection apparatus and inspection method

Abstract

To enrich an inspection which can be performed on an inspection object in a non-contact manner.SOLUTION: In the inspection device 1, the front-side radiation unit 10 radiates the inspection object 3 with first radiation light L1 for emitting photoluminescence light and second radiation light L2 scattered on the front side of the inspection object 3. The imaging unit 30 images the inspection target 3 using the photoluminescence light emitted from the inspection target 3 by the first emission light L1 and the scattered light obtained by scattering the second emission light L2 on the inspection target 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an inspection device and an inspection method. [Background technology]

[0002] There are known techniques for inspecting objects such as solar cells, semiconductors, etc. For example, Patent Document 1 discloses an inspection device for solar cells that uses photoluminescence (PL). By using PL, the object can be inspected without contact, which has the advantage of avoiding damage to the object due to contact and also being applicable even when the object is in the middle of a manufacturing process. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-163059 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for further enhancement of the above-mentioned tests that can be performed without contacting the test subject.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide an inspection device etc. that can enhance inspections that can be performed without contacting the object to be inspected. [Means for solving the problem]

[0006] In order to achieve the above object, an inspection apparatus according to a first aspect of the present invention comprises: a first irradiation unit that irradiates the inspection object with first irradiation light to cause the inspection object to emit photoluminescence light; a second irradiation unit that irradiates the inspection object with second irradiation light that is scattered on a surface of the inspection object; and an imaging unit that images the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated by the first irradiation unit and the scattered light that is scattered on the surface of the inspection object by the second irradiation unit.

[0007] In order to achieve the above object, an inspection apparatus according to a second aspect of the present invention comprises: a first irradiation unit that irradiates the inspection object with first irradiation light to cause the inspection object to emit photoluminescence light; a third irradiation unit that irradiates the inspection object with third irradiation light that passes through the inspection object; and an imaging unit that images the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated by the first irradiation unit and the transmitted light that is transmitted through the inspection object by the third irradiation light irradiated by the third irradiation unit.

[0008] In order to achieve the above object, an inspection method according to a third aspect of the present invention comprises: an irradiation step of irradiating the inspection object with first irradiation light for emitting photoluminescence light and second irradiation light scattered by the surface of the inspection object; and an imaging step of imaging the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated in the irradiation step and the scattered light scattered on the surface of the inspection object by the second irradiation light irradiated in the irradiation step.

[0009] In order to achieve the above object, an inspection method according to a fourth aspect of the present invention comprises: an irradiation step of irradiating the inspection object with first irradiation light for emitting photoluminescence light and third irradiation light that transmits through the inspection object; and an imaging step of imaging the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated in the irradiation step and the transmitted light that has passed through the inspection object by the third irradiation light irradiated in the irradiation step. [Effects of the Invention]

[0010] According to the present invention, it is possible to enhance the quality of testing that can be performed without contacting the test subject. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing the overall configuration of an inspection device according to a first embodiment. [Figure 2] 2 is a diagram showing the configuration of a front-side irradiation unit and a back-side irradiation unit in the first embodiment. FIG. [Figure 3] FIG. 2 is a diagram showing the configuration of an imaging unit in the first embodiment. [Figure 4] 4A and 4B are diagrams illustrating an example of a pre-sensor filter provided in an imaging unit in the first embodiment. [Figure 5] 5A and 5B are diagrams showing examples of wavelengths filtered by a pre-lens filter and a pre-sensor filter in the first embodiment. [Figure 6] 3 is a diagram showing an example of an image captured by an imaging section in the first embodiment. FIG. [Figure 7] FIG. 2 is a block diagram showing the configuration of an image processing unit in the first embodiment. [Figure 8] 1(a), 1(b), and 1(c) are diagrams showing examples of accumulated images of scattered light, PL light, and transmitted light, respectively, in embodiment 1. FIG. 1(d) is a diagram showing an integrated image obtained by integrating the accumulated images shown in 1(a) to 1(c). [Figure 9] 3 is a flowchart showing the flow of an inspection process executed by the inspection device according to the first embodiment. [Figure 10] FIG. 10 is a diagram showing the configuration of a first irradiation unit and a second irradiation unit in the second embodiment. [Figure 11]10 is a diagram showing an example of a pre-sensor filter provided in an imaging unit in the second embodiment. FIG. [Figure 12] 10 is a diagram showing an example of an image captured by an imaging section in the second embodiment. FIG. [Figure 13] 1A is a diagram showing a schematic diagram of a difference in the light-focusing position depending on the wavelength in a lens having chromatic aberration, and FIG. 1B is a diagram showing an example in which the light-focusing position is adjusted by a filter before the sensor in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0013] (Embodiment 1) The inspection device 1 according to the first embodiment is a device that captures an image of an inspection object 3 using a plurality of lights that are generated through different processes, including photoluminescence light (PL light), and inspects the inspection object 3 based on the captured image. Here, photoluminescence (hereinafter referred to as "PL") is luminescence caused by irradiation with electromagnetic waves (light energy), and is a phenomenon in which electrons excited by irradiating a substance with light emit light at a wavelength corresponding to the energy difference between the excited state and the ground state when they return to the ground state.

[0014] 1, the inspection device 1 includes a transport unit 5, a front-side irradiation unit 10, a back-side irradiation unit 20, an imaging unit 30, and an image processing unit 50. The front-side irradiation unit 10, the back-side irradiation unit 20, and the imaging unit 30 can be collectively called an imaging device.

[0015] The transport unit 5 transports the inspection object 3 along a predetermined transport path in a predetermined direction (+X direction in the example of FIG. 1) at a predetermined transport speed V. Hereinafter, the direction in which the inspection object 3 is transported by the transport unit 5 is defined as the X direction, the width direction of the inspection object 3 transported by the transport unit 5 is defined as the Y direction, and the vertical direction is defined as the Z direction. Furthermore, the side in the +Z direction is referred to as the front side (upper side), and the side in the -Z direction is referred to as the back side (lower side).

[0016] <Test subject 3> The inspection object 3 is an object to be inspected by the inspection device 1. One example of the inspection object 3 is a solar cell. In this case, the inspection object 3 is a solar cell using silicon, a solar cell using a compound semiconductor, a solar cell using an inductive semiconductor, or the like. Alternatively, the inspection object 3 is not limited to a solar cell using a conventional semiconductor, but may also be a perovskite solar cell or a solar cell using quantum dots. The solar cell that is the inspection object 3 may be in a state after having passed through the final manufacturing process, or in a state during the manufacturing process.

[0017] Alternatively, the inspection object 3 may be a semiconductor other than a solar cell. In this case, the inspection object 3 may be a semiconductor product such as an LED (Light Emitting Diode), memory, integrated circuit, etc., or may be in the form of a wafer before being commercialized, or may be in the form of a wafer with layers of various materials formed on it. Furthermore, the inspection object 3 is not limited to being a solar cell or a semiconductor, and may be any object made of a substance that emits PL light.

[0018] <Front side irradiation unit 10> The front-side irradiation unit 10 is a unit that irradiates light from the front side of the inspection object 3. The front-side irradiation unit 10 is disposed diagonally above the inspection object 3 that is being transported in a predetermined direction (+X direction) by the transport unit 5. The front-side irradiation unit 10 irradiates electromagnetic waves (hereinafter simply referred to as "light") in a wavelength range (wavelength band) ranging from visible light to infrared light onto the inspection object 3 that is being transported by the transport unit 5 from the front side, i.e., from the +Z direction. More specifically, the front-side irradiation unit 10 irradiates irradiation lights L1 and L2 from a direction inclined, for example, by 20° to 60° with respect to the direction perpendicular to the surface of the transported inspection object 3 (Z direction).

[0019] As shown in FIG. 2, the front-side irradiation unit 10 includes a first irradiation section 11 and a second irradiation section 12. The first irradiation section 11 irradiates the front surface of the inspection object 3 with first irradiation light L1. The first irradiation light L1 is excitation light that causes the inspection object 3 to emit PL light. In other words, the first irradiation light L1 is light in a first wavelength range that excites electrons in the inspection object 3 to emit PL light. The first wavelength range is a wavelength range that corresponds to the optical absorption edge of the inspection object 3, and more specifically, a wavelength range that is slightly shorter than the optical absorption edge of the inspection object 3 (i.e., has higher energy than the optical absorption edge).

[0020] The first irradiation unit 11 has a light source (e.g., an LED light source) that emits light in a first wavelength range, and irradiates the first irradiation light L1 emitted from the light source onto the inspection object 3 transported by the transport unit 5. When the inspection object 3 is irradiated with the first irradiation light L1, it emits PL light of a wavelength corresponding to the energy of the optical absorption edge. The imaging unit 30, which will be described later, captures an image using the PL light generated by the first irradiation light L1, making it possible to visualize the composition, properties, performance, etc. of the inspection object 3.

[0021] The second irradiating unit 12 irradiates the front surface of the inspection object 3 with second irradiation light L2. The second irradiation light L2 is light in a second wavelength range for scattering on the surface of the inspection object 3. The second wavelength range is on the wavelength side shorter than the optical absorption edge of the inspection object 3, and is a wavelength range even shorter than the first wavelength range described above so that the second irradiation light L2 does not pass through the inspection object 3 but is scattered on the surface.

[0022] The second irradiation unit 12 has a light source (e.g., an LED light source) that emits light in a second wavelength range, and irradiates the second irradiation light L2 emitted from the light source onto the inspection object 3 transported by the transport unit 5. When the inspection object 3 is irradiated with the second irradiation light L2, the irradiated second irradiation light L2 is scattered on the surface and the scattered light is emitted into the surrounding area. The scattered light generated by the second irradiation light L2 is used by the imaging unit 30 described below to capture an image, making it possible to image the surface shape of the inspection object 3.

[0023] <Backside illumination unit 20> Returning to FIG. 1, the backside illumination unit 20 is a unit that illuminates the inspection object 3 with light from the back side. The backside illumination unit 20 is disposed below the inspection object 3 that is being transported by the transport unit 5. The backside illumination unit 20 illuminates the inspection object 3 that is being transported by the transport unit 5 with electromagnetic waves in a wavelength range from visible light to infrared light vertically from below, i.e., from the -Z direction to the +Z direction.

[0024] As shown in FIG. 2, the backside illumination unit 20 includes a third illumination unit 21. The third illumination unit 21 irradiates the backside surface of the inspection object 3 with third illumination light L3. The third illumination light L3 is light in a third wavelength range that transmits through the interior of the inspection object 3. The third wavelength range is a wavelength range that allows the third illumination light L3 to transmit from the backside to the frontside of the inspection object 3. As an example, the third wavelength range is a wavelength range in the infrared region that is longer than the optical absorption edge of the inspection object 3. However, depending on the material of the inspection object 3, the third wavelength range is not limited to a wavelength range longer than the optical absorption edge of the inspection object 3, and may be any wavelength range that can transmit through the inspection object 3.

[0025] The third irradiation unit 21 has a light source (e.g., an LED light source) that emits light in a third wavelength range, and irradiates the third irradiation light L3 emitted from the light source onto the back side of the inspection object 3 being transported by the transport unit 5. The irradiated third irradiation light L3 passes through the interior of the inspection object 3 and is emitted as transmitted light to the front side of the inspection object 3. The transmitted light generated by the third irradiation light L3 is used by the imaging unit 30, which will be described later, to capture an image of the internal structure of the inspection object 3.

[0026] In each of the irradiation units 11 to 13, irradiation light L1 to L3 emitted from a light source is output to the outside via a light-guiding member (not shown). The light-guiding member guides the light emitted from the light source into a line-shaped emitted light. By passing through the light-guiding member, the irradiation area on the inspection object 3 onto which the light is irradiated extends long in the width direction (Y direction) of the inspection object 3 and becomes a thin line-shaped area in the transport direction (X direction).

[0027] The wavelengths of the illumination light L1 to L3 emitted from each of the illumination units 11 to 13 need to be appropriately selected depending on the inspection target 3 being used. Specifically, the wavelength of the first illumination light L1 is selected to be shorter than the wavelength corresponding to the optical absorption edge of the inspection target 3 so that PL is appropriately generated in the inspection target 3. Furthermore, the wavelength of the second illumination light L2 is selected depending on the material of the inspection target 3 so that the second illumination light L2 does not transmit through the inspection target 3 but is scattered at its surface. Similarly, the wavelength of the third illumination light L3 is selected depending on the material of the inspection target 3 so that the third illumination light L3 can transmit through the inspection target 3.

[0028] <Imaging unit 30> Returning to FIG. 1 , the imaging unit 30 is a unit that captures an image of the inspection object 3 by capturing an image of the inspection object 3. The imaging unit 30 is disposed above the inspection object 3 transported by the transport unit 5, and receives PL light, scattered light, and transmitted light generated from the inspection object 3. In this way, the imaging unit 30 captures an image of the inspection object 3 using the PL light, scattered light, and transmitted light.

[0029] 3, the imaging unit 30 includes a pre-lens filter 31, one lens 32, a pre-sensor filter 33, and one image sensor 34. These components are arranged so as to face perpendicularly to the surface of the inspection object 3 transported by the transport unit 5, and capture an image of the inspection object 3 from directly above.

[0030] In the inspection object 3, the PL light, scattered light, and transmitted light are emitted from linear areas 17-19 corresponding to the irradiation areas irradiated with the irradiation lights L1-L3. The imaging unit 30 captures an image of the imaging area including all of the linear areas 17-19.

[0031] The pre-lens filter 31 is an interference filter installed in front of the lens 32 to prevent unnecessary light from entering the lens 32. The pre-lens filter 31 blocks wavelength components shorter than a predetermined wavelength TH among the PL light, scattered light, and transmitted light incident from the inspection object 3. The predetermined wavelength TH is set to a wavelength shorter than the peak wavelength of any of the PL light, scattered light, and transmitted light. Since short-wavelength components shorter than the predetermined wavelength TH become large noise components, they are blocked by the pre-lens filter 31 before entering the lens 32. Note that the pre-lens filter 31 is installed at a position away from the lens 32 in FIG. 3 . However, the pre-lens filter 31 is not limited to this, and may be installed in front of the lens 32, for example, by coating the lower surface of the lens 32.

[0032] The lens 32 collects the PL light, scattered light, and transmitted light incident from the inspection object 3. The optical axis of the lens is perpendicular to the surface of the transported inspection object 3. The lens 32 simultaneously collects the PL light, scattered light, and transmitted light that have passed through the pre-lens filter 31, and forms an image on the image sensor 34.

[0033] In order to focus multiple light beams with different wavelengths, namely PL light, scattered light, and transmitted light, lens 32 is sufficiently corrected for chromatic aberration and curvature aberration in the wavelength range from visible light to infrared light. For example, it is desirable that the chromatic aberration and curvature aberration be within ±0.01% in the wavelength range from 400 nm to 1600 nm. In this way, lens 32 is a lens specialized for correcting chromatic aberration and curvature aberration, making it possible to image multiple light beams with different wavelengths at the same imaging distance.

[0034] The pre-sensor filter 33 is an interference filter installed between the lens 32 and the image sensor 34 to prevent unnecessary light from entering the image sensor 34. The pre-sensor filter 33 has a plurality of individual filters for each region, each of which corresponds one-to-one to the PL light, scattered light, and transmitted light incident from the inspection object 3.

[0035] Specifically, as shown in Fig. 4, the pre-sensor filter 33 has three individual filters, a scattered light filter 33a, a PL light filter 33b, and a transmitted light filter 33c, separated into three regions. The scattered light filter 33a individually transmits scattered light that is generated by the second irradiation light L2 scattered on the surface of the inspection object 3, and blocks wavelength components other than the scattered light. The PL light filter 33b individually transmits PL light that is emitted from the inspection object 3 by the first irradiation light L1, and blocks wavelength components other than the PL light. The transmitted light filter 33c individually transmits transmitted light that is generated by the third irradiation light L3 passing through the inspection object 3, and blocks wavelength components other than the transmitted light.

[0036] Since the PL light, scattered light, and transmitted light are collected by one lens 32, the positions in the X and Y directions are reversed on the inspection object 3 and on the image sensor 34. Therefore, the correspondence between the three areas 17 to 19 and the three individual filters in the pre-sensor filter 33 is reversed in the X direction. Specifically, scattered light filter 33a, which transmits scattered light incident from area 17 on the -X side of inspection object 3, is located on the +X side, and transmitted light filter 33c, which transmits transmitted light incident from area 19 on the +X side of inspection object 3, is located furthest on the -X side.

[0037] 5 shows an example of wavelength ranges filtered by the pre-lens filter 31 and the pre-sensor filter 33. Light traveling from the inspection object 3 toward the lens 32 is first blocked by the pre-lens filter 31 in front of the lens 32, with wavelength components shorter than the predetermined wavelength TH (the darkly colored parts in FIG. 5).

[0038] The light transmitted through the pre-lens filter 31 then passes through the lens 32 and is filtered by the pre-sensor filter 33 into wavelength ranges (lightly shaded areas in FIG. 5) that include the peak wavelengths of the PL light, scattered light, and transmitted light incident from the inspection object 3. The wavelength ranges filtered by each individual filter in the pre-sensor filter 33 are set to cover, for example, 50 to 90% of the spectral intensity, based on the peak wavelength of the corresponding light. Note that the wavelength values ​​in FIG. 5 are merely examples.

[0039] Returning to Fig. 3, the image sensor 34 is a single area sensor that is sensitive to both visible light and infrared light (for example, in the wavelength range of 400 to 1600 nm). The image sensor 34 is disposed at a position where light is collected by the lens 32. The image sensor 34 receives PL light, scattered light, and transmitted light that are emitted from the inspection object 3 and have passed through the pre-lens filter 31, the lens 32, and the pre-sensor filter 33, and generates a captured image.

[0040] More specifically, the image sensor 34 includes photodiodes arranged in an array and a readout circuit using a complementary metal oxide semiconductor (CMOS). The photodiodes are, for example, made of InGaAs (indium gallium arsenide), a compound semiconductor. The PL light, scattered light, and transmitted light incident on the image sensor 34 are photoelectrically converted by the photodiodes and read out as signals by a readout circuit (not shown). The readout circuit includes, for example, an analog / digital (A / D) converter that converts analog signals representing an image captured by the image sensor 34 into digital data. The signals read out by the image sensor 34 are output to the image processing unit 50.

[0041] By using the image sensor 34 having sensitivity over such a wide wavelength range, it is possible to simultaneously capture images of the inspection object 3 using light in different wavelength ranges, namely PL light, scattered light, and transmitted light, which makes it possible to inspect the inspection object 3 at high speed and from multiple angles.

[0042] FIG. 6 shows an example of a captured image 70 captured by the imaging unit 30. The captured image 70 is an image captured simultaneously using PL light, scattered light, and transmitted light incident from the inspection object 3. As described above, the correspondence between the inspection object 3 and the image sensor 34 is reversed in the X and Y directions. However, for ease of understanding, the X and Y coordinates in the captured image 70 shown in FIG. 6 are made to match the X and Y coordinates on the inspection object 3. This also applies to the subsequent figures.

[0043] Specifically, the captured image 70 is divided into three regions 71 to 73 corresponding to the scattered light filter 33a, the PL light filter 33b, and the transmitted light filter 33c. The first region 71 is the scattered light of the second irradiation light L2 scattered on the surface of the inspection object 3, and is captured by the image sensor 34 receiving the scattered light that has passed through the scattered light filter 33a. The second region 72 is the PL light emitted from the inspection object 3 by the first irradiation light L1, and is captured by the image sensor 34 receiving the PL light that has passed through the PL light filter 33b. The third region 73 is the transmitted light of the third irradiation light L3 that has passed through the inspection object 3, and is captured by the image sensor 34 receiving the transmitted light that has passed through the transmitted light filter 33c.

[0044] In this way, images are captured by region using scattered light, PL light, and transmitted light, so that linear area 17 is captured in first region 71, linear area 18 is captured in second region 72, and linear area 19 is captured in third region 73. The portions of captured image 70 corresponding to linear areas 17-19 (white portions in FIG. 6) exhibit brighter luminance values ​​(pixel values) than the other portions (colored portions in FIG. 6). In this way, one captured image 70 contains images using scattered light, PL light, and transmitted light.

[0045] The imaging unit 30 repeatedly captures such captured images 70 at predetermined time intervals Δt, thereby acquiring a plurality of captured images 70. More specifically, the imaging unit 30 captures a captured image 70 each time the inspection object 3 is transported by the transport unit 5 a distance d corresponding to one pixel. For this purpose, the time interval Δt is set to "Δt=d / V," which is the time obtained by dividing the distance d corresponding to one pixel by the transport speed V. By repeatedly capturing images at time intervals Δt in this manner, the imaging unit 30 can capture an image of the entire area of ​​the inspection object 3, from one end to the other, being transported by the transport unit 5, using scattered light, PL light, and transmitted light.

[0046] <Image processing unit 50> 1, the image processing unit 50 is a unit that acquires information related to the inspection of the inspection object 3 based on the captured image 70 acquired by the imaging unit 30. The image processing unit 50 is specifically an information processing device such as a personal computer or a cloud server.

[0047] Here, the information relating to the inspection of the inspection object 3 is, for example, information on the presence or absence of defects in the inspection object 3, or information on whether the inspection object 3 satisfies a predetermined performance standard. Alternatively, the information relating to the inspection of the inspection object 3 may be, for example, an image processed from the captured image 70 for the purpose of inspecting the inspection object 3, such as integrated images 81 to 83 or an integrated image 85, which will be described later.

[0048] 7, the image processing unit 50 includes a control unit 51, a storage unit 52, an input receiving unit 53, a display unit 54, and a communication unit 55. The control unit 51 includes a central processing unit (CPU), a read-only memory (ROM), and a random access memory (RAM). The CPU includes a microprocessor or the like and is a central processing unit that executes various processes and calculations. In the control unit 51, the CPU reads out a control program stored in the ROM and controls the overall operation of the image processing unit 50 while using the RAM as a work memory. The control unit 51 may also include a processor for image processing, such as a digital signal processor (DSP) or a graphics processing unit (GPU).

[0049] The storage unit 52 is a non-volatile memory such as a flash memory or a hard disk. The storage unit 52 stores programs and data executed by the control unit 51 and data generated by the control unit 51. The input receiving unit 53 includes input devices such as a keyboard, a mouse, and a touch panel, and receives operational input from a user. The display unit 54 includes a display device such as a liquid crystal display or an organic EL (Electro Luminescence) display, and displays various images under the control of the control unit 51. For example, the display unit 54 displays an image showing the inspection results obtained by the inspection device 1. The communication unit 55 includes a communication interface for communicating with devices external to the image processing unit 50. For example, the communication unit 55 communicates with external devices, including the imaging unit 30, in accordance with well-known communication standards such as a LAN (Local Area Network) or a USB (Universal Serial Bus).

[0050] The control unit 51 functionally includes a cutout unit 110, an integration unit 120, an integration unit 130, an inspection unit 140, and an output unit 150. In the control unit 51, the CPU reads a program stored in the ROM into the RAM, and executes and controls the program, thereby functioning as each of these units.

[0051] The cropping unit 110 crops out a target image to be inspected from the captured image 70 captured by the imaging unit 30. Specifically, the cropping unit 110 utilizes a region of interest (ROI) function to crop out partial images corresponding to the linear areas 17-19 from regions 71-73 in each of the multiple captured images 70 repeatedly acquired by the imaging unit 30 at time intervals Δt.

[0052] The accumulating unit 120 generates an accumulated image by accumulating the luminance values ​​of pixels in the plurality of captured images 70 acquired by the imaging unit 30, where the same position on the inspection object 3 is captured. Specifically, the accumulating unit 120 regards each of the partial images cut out from the plurality of captured images 70 by the cutout unit 110 as a TDI (Time Delay Integration) sensor, and then accumulates the luminance values ​​while synchronizing with the conveying speed V of the inspection object 3. By accumulating the luminance values ​​in the plurality of captured images 70, it is possible to lengthen the exposure time and suppress fixed noise, which is advantageous for improving sensitivity in imaging.

[0053] The integrating unit 120 integrates the luminance values ​​of pixels captured at the same position on the inspection object 3 for each of the PL light, scattered light, and transmitted light incident from the inspection object 3. As a result, the integrating unit 120 generates an integrated image 81 using scattered light as shown in Fig. 8(a) from the partial image cut out from the region 71, generates an integrated image 82 using PL light as shown in Fig. 8(b) from the partial image cut out from the region 72, and generates an integrated image 83 using transmitted light as shown in Fig. 8(c) from the partial image cut out from the region 73.

[0054] The integrated image 81 is an image acquired using scattered light, and therefore represents the surface shape of the inspection object 3. In FIG. 8(a), the defects captured in the integrated image 81 are defects such as cracks, protrusions, and depressions present on the surface of the inspection object 3. In contrast, the integrated image 82 is an image acquired using PL light, and therefore represents the composition, properties, and performance of the inspection object 3. In FIG. 8(b), the defects captured in the integrated image 82 are defects such as crystal defects in the inspection object 3. Here, crystal defects are defects such as a break in the regular arrangement of crystals or the presence of unnecessary atoms, and are defects that can occur during the crystal growth process. In addition, the integrated image 83 is an image acquired using transmitted light, and therefore represents the internal structure of the inspection object 3. In FIG. 8(c), the defects captured in the integrated image 83 correspond to defects such as voids present inside the inspection object 3.

[0055] 7, the integration unit 130 integrates the multiple integrated images 81 to 83 generated by the accumulation unit 120 to generate an integrated image 85. Specifically, the integration unit 130 adds up the luminance values ​​of the same coordinates in the three integrated images 81 to 83 shown in FIGS. 8(a) to 8(c) to generate an integrated image 85 as shown in FIG. 8(d). The luminance value of each pixel in the integrated image 85 is the sum of the luminance values ​​of the pixels at the same coordinates in the integrated images 81 to 83.

[0056] Through integration by the integration unit 130, defects captured separately in the three integrated images 81 to 83 are integrated into a single integrated image 85. This allows the defects captured separately in the three integrated images 81 to 83 to be correlated and evaluated. For example, if a crack captured in integrated image 81 is located within the region of a crystal defect captured in integrated image 82, the position of the crack can be identified as the core of the crystal defect. In other words, the core of the crystal defect can be identified from integrated image 81 while identifying the range of influence of the crystal defect from integrated image 82. Furthermore, if a void captured in integrated image 83 is located within the region of a crystal defect captured in integrated image 82, the causal relationship between the void and the crystal defect can be evaluated.

[0057] In the inspection device 1 according to the first embodiment, the three integrated images 81 to 83 are acquired using one lens 32 and one image sensor 34, which is an area sensor, and therefore there is high consistency in resolution and position among the integrated images 81 to 83. As a result, a highly accurate integrated image 85 can be generated.

[0058] 7, the inspection unit 140 inspects the inspection object 3 based on the integrated images 81 to 83 generated by the integrating unit 120 or the integrated image 85 generated by the integrating unit 130. Specifically, the inspection unit 140 analyzes the luminance distribution of the integrated images 81 to 83 or the integrated image 85 to determine whether or not a defect exists.

[0059] For example, as shown in FIGS. 8(a) to 8(d), when a defect is captured in the accumulated images 81 to 83 or the integrated image 85, the inspection unit 140 detects that the inspection object 3 contains a defect. The inspection unit 140 then identifies the type of defect based on feature quantities such as the shape and size of the captured defect. Furthermore, when a defect is captured in two or more of the accumulated images 81 to 83, the inspection unit 140 analyzes the relevance of the defects based on their positional relationships. Alternatively, even when there is no defect in the inspection object 3, the inspection unit 140 may determine whether the inspection object 3 satisfies a predetermined performance standard from the brightness distribution of the accumulated images 81 to 83 or the integrated image 85.

[0060] The output unit 150 outputs the inspection results obtained by the inspection unit 140. For example, the output unit 150 displays an image showing the evaluation results of the inspection object 3 on the display unit 54 to notify the user. Alternatively, the output unit 150 may output the inspection results by voice, or may output the inspection results to an external device via the communication unit 55.

[0061] The image processing unit 50 does not necessarily have to have the function of the inspection unit 140, and a device external to the image processing unit 50 may have the function of the inspection unit 140. In this case, the output unit 150 outputs the integrated images 81 to 83 generated by the integrating unit 120 or the integrated image 85 generated by the integrating unit 130 to the external device via the communication unit 55. Then, the external device may execute the processing of the inspection unit 140 described above based on the integrated images 81 to 83 or the integrated image 85.

[0062] Next, the flow of the inspection process executed by the inspection device 1 will be described with reference to the flowchart shown in FIG.

[0063] When the inspection process starts, the transport unit 5 transports the inspection object 3 along a predetermined transport path at a constant transport speed V (step S1). Then, the front-side irradiation unit 10 and the back-side irradiation unit 20 turn on their respective light sources to irradiate the inspection object 3 transported by the transport unit 5 with irradiation lights L1 to L3 in different wavelength ranges (step S2). Steps S1 and S2 are examples of a transport step and an irradiation step, respectively.

[0064] When the front-side irradiation unit 10 and the back-side irradiation unit 20 irradiate the irradiation light L1 to L3, the imaging section 30 images the inspection object 3 using PL light, scattered light, and transmitted light generated from the inspection object 3 by the irradiated irradiation light L1 to L3 (step S3). In this way, the imaging section 30 acquires, for example, the captured image 70 shown in FIG. 6. More specifically, the imaging section 30 acquires a plurality of captured images 70 by repeatedly capturing images of the transported inspection object 3 at a constant time interval Δt. Step S3 is an example of an imaging step.

[0065] Next, the image processing unit 50 analyzes each of the multiple captured images 70 acquired by the imaging unit 30, and acquires information related to the inspection of the inspection object 3. Specifically, the image processing unit 50 functions as a cutout unit 110, and cuts out partial images corresponding to areas 17 to 19 where PL light, scattered light, and transmitted light are generated from each of the multiple captured images 70 acquired (step S4).

[0066] Next, the image processing unit 50 functions as the accumulating unit 120 and accumulates the luminance values ​​of pixels captured at the same position on the inspection object 3 for each of the extracted partial images (step S5). As a result, the image processing unit 50 generates, for example, accumulated images 81 to 83 shown in FIGS. 8(a) to 8(c).

[0067] After generating the integrated images 81 to 83, the image processing unit 50 functions as the integrating unit 130 and integrates the integrated images 81 to 83 (step S6). As a result, the image processing unit 50 generates, for example, an integrated image 85 shown in FIG. 8(d).

[0068] After generating the integrated image 85, the image processing unit 50 functions as the inspection unit 140 and inspects the inspection object 3 by analyzing the accumulated images 81 to 83 or the integrated image 85 (step S7). Specifically, the image processing unit 50 determines whether or not the inspection object 3 has a defect or the like, or whether or not the inspection object 3 satisfies a predetermined performance standard.

[0069] Next, the image processing unit 50 functions as the output unit 150 and outputs the inspection result in step S7 to the outside by display, voice, communication, etc. (step S8). This completes the inspection process shown in Fig. 9. Note that steps S4 to S8 are an example of image processing steps.

[0070] As described above, the inspection device 1 according to the first embodiment irradiates the inspection object 3 with irradiation light L1-L3 and captures an image of the inspection object 3 using PL light, scattered light, and transmitted light generated by the inspection object 3 due to the irradiation light L1-L3. This allows for non-contact inspection of the inspection object 3, eliminating the risk of damaging the inspection object 3. Furthermore, since inspection is possible even during the manufacturing process, it becomes possible to identify defects that occur during the manufacturing process. Furthermore, because the inspection object 3 is inspected using not only PL light but also scattered light and transmitted light, it is possible to combine inspection of the composition, properties, and performance using PL light, inspection of the surface shape using scattered light, and inspection of the internal structure using transmitted light. As a result, the inspection object 3 can be inspected from multiple perspectives, thereby enhancing the inspection process.

[0071] Furthermore, the inspection device 1 according to the first embodiment simultaneously irradiates the inspection object 3 with irradiation light L1 to L3 and simultaneously captures images of all of the areas 17 to 19 where PL light, scattered light, and transmitted light are generated, making it possible to capture images using light of multiple wavelengths in a single scan. This allows the inspection object 3 to be inspected at high speed, leading to a reduction in inspection time.

[0072] In particular, the inspection device 1 according to the first embodiment images the inspection object 3 with light of multiple wavelengths using a single imaging system consisting of a single lens that can handle wavelength ranges from visible light to infrared light and a single image sensor 34. Since there is no need to provide multiple imaging systems for imaging with light of multiple wavelengths, the size and cost of the device can be reduced, leading to a smaller and lighter device.

[0073] Furthermore, the inspection device 1 according to the first embodiment images the inspection object 3 using PL light, scattered light, and transmitted light with a single imaging system, improving the consistency of resolution and position between the images captured using PL light, scattered light, and transmitted light. This allows the images captured using PL light, scattered light, and transmitted light to be compared with high accuracy, improving the accuracy of evaluation of the inspection object 3.

[0074] Furthermore, the inspection device 1 according to the first embodiment does not require a rotation mechanism such as a filter changer for changing filters because it filters PL light, scattered light, and transmitted light using a single pre-sensor filter 33. This makes it possible to prevent particles from adhering to the inspection object 3 due to the driving of the rotation mechanism, thereby reducing the effort required to clean particles adhering to the inspection object 3 in a subsequent process.

[0075] (Embodiment 2) Next, a description will be given of embodiment 2. Descriptions of the same configurations and functions as embodiment 1 will be omitted where appropriate.

[0076] The inspection device 1 according to the first embodiment irradiates the inspection object 3 with irradiation light L1 to L3, and captures an image of the inspection object 3 using PL light, scattered light, and transmitted light generated from the inspection object 3 by the irradiation light L1 to L3. In contrast, the inspection device 1 according to the second embodiment irradiates the inspection object 3 with excitation light in a plurality of different wavelength ranges as irradiation light L1 for causing the inspection object 3 to emit PL light, causing the inspection object 3 to emit PL light of a plurality of different wavelengths.

[0077] In the second embodiment, the inspection object 3 is a laminate having multiple layers. Specifically, as shown in FIG. 10, the inspection object 3 in the second embodiment has three layers: a top cell 3a, a middle cell 3b, and a bottom cell 3c. As an example, the inspection object 3 in the second embodiment is a solar cell having multiple bandgaps. Solar cells having multiple bandgaps are multi-junction solar cells such as stacked, tandem, and multi-junction solar cells. An example of a multi-junction solar cell is a III-V group (III-V group) semiconductor solar cell.

[0078] In the test object 3, the top cell 3a, middle cell 3b, and bottom cell 3c are made of different materials and have different bandgaps so as to efficiently generate solar energy. When irradiated with excitation light, the top cell 3a, middle cell 3b, and bottom cell 3c emit PL light of different wavelengths corresponding to their respective bandgaps.

[0079] 10, the inspection device 1 according to the second embodiment includes a front-side irradiation unit 10 provided with a first irradiation unit 11 and a second irradiation unit 12, and a back-side irradiation unit 20 provided with a third irradiation unit 21. The second irradiation unit 12 and the third irradiation unit 21 are the same as those in the first embodiment. Specifically, the second irradiation unit 12 irradiates the inspection target 3 from the front side with irradiation light L2, which is scattered on the surface of the inspection target 3 to generate scattered light. The third irradiation unit 21 irradiates the inspection target 3 from the back side with irradiation light L3, which is transmitted through the interior of the inspection target 3 to generate transmitted light.

[0080] In the front-side irradiation unit 10, the first irradiation section 11 includes three irradiation sections 11a to 11c that irradiate irradiation light L1 with irradiation light L11 to L13 as the first irradiation light L1. The irradiation light L11 to L13 are excitation light with different wavelength ranges that excite electrons in each layer of the top cell 3a, middle cell 3b, and bottom cell 3c in the inspection object 3, causing each layer to emit PL light.

[0081] The irradiators 11a to 11c irradiate different irradiation areas on the inspection target 3 with irradiation light L11 to L13 in different wavelength ranges. Specifically, the irradiator 11a irradiates the top cell 3a with irradiation light L1 having a peak wavelength shorter than the optical absorption edge of the material of the top cell 3a to generate PL. The irradiator 11b irradiates the middle cell 3b with irradiation light L2 having a peak wavelength shorter than the optical absorption edge of the material of the middle cell 3b to generate PL. The irradiator 11c irradiates the bottom cell 3c with irradiation light L3 having a peak wavelength shorter than the optical absorption edge of the material of the bottom cell 3c to generate PL. The wavelengths of the irradiation light L1 to L3 need to be appropriately selected depending on the inspection target 3 to ensure that PL is appropriately generated in the inspection target 3.

[0082] When the irradiation units 11a to 11c irradiate the irradiation light L11 to L13 in this manner, the top cell 3a, middle cell 3b, and bottom cell 3c emit PL light having wavelengths corresponding to the optical absorption edges of the respective layers. As a result, PL light of three different wavelengths is emitted from the inspection object 3. The imaging unit 30 receives light of five different wavelengths: the PL light of the three wavelengths thus emitted from the inspection object 3, scattered light due to the irradiation light L2, and transmitted light due to the irradiation light L3. The imaging unit 30 then simultaneously images the inspection object 3 using light of the five different wavelengths using one lens 32 and one image sensor 34, thereby acquiring an image of the inspection object 3.

[0083] More specifically, whereas the imaging unit 30 in the first embodiment includes a mechanism for simultaneously imaging the inspection target 3 with light of three different wavelengths, the imaging unit 30 in the second embodiment includes a mechanism for simultaneously imaging the inspection target 3 with light of five different wavelengths. Specifically, in the second embodiment, the pre-sensor filter 33 includes five individual filters, one for each region, as shown in FIG. 11 . In other words, the PL filter 33b includes three filters, a top cell PL filter, a middle cell PL filter, and a bottom cell PL filter, for receiving PL light emitted from each of the three layers, the top cell 3a, the middle cell 3b, and the bottom cell 3c. The pre-sensor filter 33 individually transmits the PL light, scattered light, and transmitted light emitted from the three layers of the inspection target 3 using the PL filter 33b including these three filters, the scattered light filter 33a, and the transmitted light filter 33c, which are the same as those in the first embodiment.

[0084] The imaging unit 30 simultaneously captures an image of the inspection object 3 using light of five different wavelengths, namely, PL light emitted from three layers of the inspection object 3, scattered light, and transmitted light, to obtain, for example, a captured image 70 shown in FIG. 12. The captured image 70 in the second embodiment is divided into five regions 71, 72a, 72b, 72c, and 73 corresponding to the five individual filters in the pre-sensor filter 33. The regions 72a to 72c are captured by the image sensor 34 receiving PL light that has passed through the top cell PL filter, middle cell PL filter, and bottom cell PL filter in the PL filter 33b, respectively. The five regions 71, 72a, 72b, 72c, and 73 in the captured image 70 capture linear areas 17, 18a, 18b, 18c, and 19, respectively. The imaging section 30 acquires a plurality of captured images 70 by repeatedly acquiring such captured images 70 at predetermined time intervals Δt.

[0085] The image processing unit 50 acquires information related to the inspection of the inspection object 3 based on the captured image 70 acquired by the imaging unit 30. Specifically, the cropping unit 110 crops five partial images corresponding to the linear areas 17, 18a, 18b, 18c, and 19 from the five regions 71, 72a, 72b, 72c, and 73, respectively. The integrating unit 120 generates five integrated images corresponding to the areas 17, 18a, 18b, 18c, and 19 by integrating the luminance values ​​of pixels captured at the same positions on the inspection object 3 for each of the five partial images cropped by the cropping unit 110. In the first embodiment, the integrating unit 120 generates one integrated image 82 as an image captured using PL light. In the second embodiment, however, the integrating unit 120 generates an integrated image for each of the three layers, the top cell 3a, the middle cell 3b, and the bottom cell 3c, using PL light emitted from each of the three layers.

[0086] The integrating unit 130 generates an integrated image by integrating the five integrated images generated by the integrating unit 120. The inspecting unit 140 inspects the inspection object 3 based on the five integrated images generated by the integrating unit 120 or the integrated image generated by the integrating unit 130. For example, the inspecting unit 140 determines whether or not defects exist in each of the three layers included in the inspection object 3 based on integrated images generated individually for each of the three layers. Alternatively, if defects are captured in two or more of the five integrated images, the inspecting unit 140 analyzes the relevance of the defects based on the positional relationship of the defects. Furthermore, the inspecting unit 140 may determine whether or not the inspection object 3 satisfies a predetermined performance standard based on the brightness distribution of the integrated image or the integrated image.

[0087] As described above, the inspection device 1 according to the second embodiment irradiates the inspection object 3 with irradiation light L11 to L13 in different wavelength ranges to emit PL light, and irradiation light L2 and L3 to generate scattered light and transmitted light. The inspection device 1 according to the second embodiment then simultaneously captures an image of the inspection object 3 using light of five wavelengths, namely, the PL light of three different wavelengths emitted from the inspection object 3, the scattered light, and the transmitted light. In the second embodiment, an integrated image is generated separately for each of the three layers included in the inspection object 3, so that more detailed inspection information can be obtained compared to the first embodiment, enabling more comprehensive inspections.

[0088] In the second embodiment, the inspection object 3 is a multi-junction solar cell having three layers. However, the number of layers of the inspection object 3 is not limited to three, and may be two, four or more. If the number of layers of the inspection object 3 is other than three, the number of light sources in the first irradiation unit 11 and the number of individual filters in the PL light filter 33b are not three, but are set to the same number as the number of layers of the inspection object 3, i.e., the number of wavelengths of PL light emitted from the inspection object 3.

[0089] Alternatively, the test object 3 does not need to be clearly divided into multiple layers as long as it emits PL light of multiple different wavelengths when irradiated with excitation light. For example, the test object 3 may be a so-called multi-band solar cell in which multiple materials that emit PL light of different wavelengths are mixed in one layer. Furthermore, the test object 3 may be a semiconductor other than a solar cell or an object other than a semiconductor as long as it is made of a material that emits PL light of multiple different wavelengths.

[0090] (Variation) Although the embodiments of the present invention have been described above, it is possible to combine the embodiments, or to modify or omit the embodiments as appropriate.

[0091] For example, in the above embodiment, the inspection device 1 includes first to third irradiation units 11, 12, and 21, irradiates the inspection object 3 with irradiation light L1 to L3, and captures an image of the inspection object 3 using PL light, scattered light, and transmitted light generated from the inspection object 3 by the irradiation light L1 to L3. However, the inspection device 1 is not limited to using all of PL light, scattered light, and transmitted light. For example, the inspection device 1 may capture an image of the inspection object 3 using PL light and scattered light without using transmitted light. Alternatively, the inspection device 1 may capture an image of the inspection object 3 using PL light and transmitted light without using scattered light. The same applies to the case where PL light of multiple different wavelengths is used as the PL light, as in embodiment 2.

[0092] When transmitted light is not used, the inspection device 1 does not need to include the third irradiation unit 21 that irradiates the inspection object 3 with the third irradiation light L3. In other words, the inspection device 1 does not need to include the backside irradiation unit 20. In this case, the inspection device 1 irradiates the inspection object 3 with irradiation light L1 and L2 from the first irradiation unit 11 and the second irradiation unit 12 provided in the frontside irradiation unit 10 to generate PL light and scattered light. Then, the imaging unit 30 images the inspection object 3 using the PL light and scattered light to obtain a captured image 70, and the image processing unit 50 obtains information related to the inspection of the inspection object 3 based on the captured image 70.

[0093] When scattered light is not used, the inspection device 1 does not need to include the second irradiation unit 12 in the front-side irradiation unit 10 that irradiates the inspection object 3 with the second irradiation light L2. In this case, the inspection device 1 irradiates the inspection object 3 with irradiation light L1 and L3 from the first irradiation unit 11 provided in the front-side irradiation unit 10 and the third irradiation unit 21 provided in the back-side irradiation unit 20, generating PL light and transmitted light. The imaging unit 30 then images the inspection object 3 using the PL light and transmitted light to obtain a captured image 70, and the image processing unit 50 obtains information related to the inspection of the inspection object 3 based on the captured image 70.

[0094] In this way, even when only PL light and scattered light or only PL light and transmitted light are used, rather than using all of PL light, scattered light, and transmitted light, the effect of enhancing the inspection can be obtained compared to when only PL light is used. Furthermore, since imaging with light of multiple wavelengths is possible with a single scan, the inspection object 3 can be inspected at high speed. Which of PL light, scattered light, and transmitted light to use, and how many different wavelengths of PL light to use as PL light, can be freely combined depending on the structure and material of the inspection object 3 used and the items to be inspected.

[0095] In the above embodiment, the lens 32 used has chromatic aberration sufficiently corrected in the wavelength range from visible light to infrared light. However, even if the chromatic aberration of the lens 32 is large, the influence of the chromatic aberration of the lens 32 can be suppressed by adjusting the thickness of each individual filter in the pre-sensor filter 33. Specifically, the thickness of each of the multiple individual filters (scattered light filter 33a, PL light filter 33b, and transmitted light filter 33c) in the pre-sensor filter 33 in the optical axis direction (Z direction) of the lens 32 may be different from one another depending on the wavelength of light passing through each individual filter, provided that the lens 32 has chromatic aberration.

[0096] Specifically, Fig. 13(a) shows the difference in focusing positions F1 to F3 when light of different wavelengths is focused by lens 32 with chromatic aberration. For the sake of explanation, Fig. 13(a) shows a case where pre-sensor filter 33 is not provided between lens 32 and image sensor 34. As shown in Fig. 13(a), when lens 32 has chromatic aberration, the focal length changes depending on the wavelength of light incident on lens 32, and therefore the focusing positions F1 to F3 of light of each wavelength shift in the Z direction.

[0097] In contrast to this, Fig. 13(b) shows an example in which a pre-sensor filter 33 is installed between the lens 32 and the image sensor 34, and the thicknesses of three individual filters in the pre-sensor filter 33 are made different, thereby adjusting the light collection positions F1 to F3 for each wavelength. Note that for ease of understanding, Fig. 13(b) only shows the vicinity of the three individual filters and the image sensor 34, and does not include the lens 32. Also, the dimensions do not necessarily match the actual dimensions.

[0098] 13(b), of the three individual filters, scattered light filter 33a is made the thickest, and transmitted light filter 33c is made the thinnest. As a result, the focusing position F1 of scattered light generated by irradiation light L1 is adjusted to be farther away from lens 32, and the focusing position F3 of transmitted light generated by irradiation light L3 is adjusted to be closer to lens 32. As a result, the deviation in the Z direction between the three focusing positions F1 to F3 can be reduced.

[0099] In this way, even if the chromatic aberration of the lens 32 is large, by providing differences in thickness between the individual filters in the pre-sensor filter 33, it is possible to adjust the focal positions of multiple light beams of different wavelengths on the image sensor 34. Therefore, at the same imaging distance, it is possible to image the inspection object 3 using multiple light beams of different wavelengths, such as scattered light, PL light, and transmitted light.

[0100] Note that the magnitude of chromatic aberration for each wavelength varies depending on the design of lens 32 (including the design of the coating of lens 32), and therefore the difference in thickness of the individual filters is not limited to the example shown in Fig. 13(b). For example, depending on the design of lens 32, the scattered light filter 33a of the three individual filters may be made the thinnest, and the transmitted light filter 33c may be made the thickest.

[0101] Furthermore, unlike in the case where the pre-sensor filter 33 has five individual filters as in the second embodiment, the number of individual filters in the pre-sensor filter 33, i.e., the number of light of different wavelengths incident on the lens 32 from the inspection object 3, is not limited to three. Even if the pre-sensor filter 33 has a number other than three individual filters, the thicknesses of the individual filters may be different from one another so as to reduce the deviation in the Z direction of the focusing positions of the light passing through each individual filter.

[0102] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to illustrate the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined not by the embodiments but by the claims. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention. [Explanation of symbols]

[0103] 1 inspection device, 2 imaging device, 3 inspection object, 3a top cell, 3b middle cell, 3c bottom cell, 5 transport unit, 10 front side irradiation unit, 11, 11a to 11c, 12, 21 irradiation unit, 17 to 19, 18a to 18c area, 20 back side irradiation unit, 30 imaging unit, 31 pre-lens filter, 32 lens, 33 pre-sensor filter, 33a scattered light filter, 33b PL light filter, 33c transmitted light filter, 34 image sensor, 50 image processing unit, 51 control unit, 52 memory unit, 53 input reception unit, 54 display unit, 55 communication unit, 70 captured image, 71 to 73, 72a to 72c area, 81 to 83 accumulated image, 85 integrated image, 110 cut-out unit, 120 accumulation unit, 130 integration unit, 140 Inspection unit, 150 Output unit, F1~F3 Light collection position, L1~L3, L11~L13 Irradiation light

Claims

1. a first irradiation unit that irradiates the inspection object with first irradiation light to cause the inspection object to emit photoluminescence light; a second irradiation unit that irradiates the inspection object with second irradiation light that is scattered by a surface of the inspection object; an imaging unit that images the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated by the first irradiation unit and the scattered light that is generated by scattering the second irradiation light irradiated by the second irradiation unit on the surface, Inspection equipment.

2. The imaging unit a lens that collects the photoluminescent light and the scattered light; an image sensor that receives the photoluminescence light and the scattered light collected by the lens; The inspection device according to claim 1 .

3. the imaging unit further includes a pre-sensor filter between the lens and the image sensor; the pre-sensor filter has, in separate regions, a photoluminescence light filter that transmits the photoluminescence light and a scattered light filter that transmits the scattered light; The inspection device according to claim 2 .

4. the first irradiating unit irradiates the inspection object with irradiation light in a plurality of wavelength ranges as the first irradiation light to cause photoluminescence light of a plurality of different wavelengths to be emitted; The imaging unit images the inspection object using photoluminescence light of the plurality of wavelengths emitted from the inspection object by irradiation light of the plurality of wavelength ranges irradiated by the first irradiation unit and the scattered light. The inspection device according to any one of claims 1 to 3.

5. the first irradiation unit and the second irradiation unit irradiate the inspection object, which is transported at a predetermined transport speed, with the first irradiation light and the second irradiation light, respectively; the imaging unit repeatedly images the inspection object being transported at the transport speed at predetermined time intervals using the photoluminescent light and the scattered light, thereby obtaining a plurality of captured images; an image processing unit that generates an integrated image by integrating luminance values ​​of pixels in the plurality of captured images at the same position on the inspection object, The inspection device according to any one of claims 1 to 3.

6. a third irradiation unit that irradiates the inspection object with third irradiation light that transmits through the inspection object, the imaging unit captures an image of the inspection object using the photoluminescence light, the scattered light, and transmitted light obtained by transmitting the third irradiation light irradiated by the third irradiation unit through the inspection object. The inspection device according to claim 1 .

7. The imaging unit a lens that collects the photoluminescent light, the scattered light, and the transmitted light; an image sensor that receives the photoluminescence light, the scattered light, and the transmitted light collected by the lens and that is sensitive to both visible light and infrared light; The inspection device according to claim 6.

8. a first irradiation unit that irradiates the inspection object with first irradiation light to cause the inspection object to emit photoluminescence light; a third irradiation unit that irradiates the inspection object with third irradiation light that transmits through the inspection object; an imaging unit that images the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated by the first irradiation unit and the transmitted light that is the third irradiation light irradiated by the third irradiation unit and transmitted through the inspection object, Inspection equipment.

9. an irradiation step of irradiating the inspection object with first irradiation light for emitting photoluminescence light and second irradiation light scattered by the surface of the inspection object; an imaging step of imaging the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated in the irradiation step and the scattered light resulting from scattering on the surface of the inspection object by the second irradiation light irradiated in the irradiation step, Testing method.

10. an irradiation step of irradiating the inspection object with first irradiation light for emitting photoluminescence light and third irradiation light that transmits through the inspection object; an imaging step of imaging the inspection object using the photoluminescence light emitted from the inspection object by the first irradiation light irradiated in the irradiation step and the transmitted light which is transmitted through the inspection object by the third irradiation light irradiated in the irradiation step, Testing method.

Images