Inspection device, and method for controlling inspection device

Abstract

To provide a technique to enable accurate inspection of an inspection area through single photographing even when the inspection area is large or a plurality of inspection areas are simultaneously inspected.SOLUTION: An inspection device photographs an inspection area that is irradiated with light by at least part of a plurality of light sources that irradiate the inspection area with light, and conducts inspection related to the inspection area on the basis of a photographed image obtained through the photographing. The plurality of light sources are arranged at positions where virtual images corresponding to the light sources surround the inspection area.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to inspection techniques. [Background technology]

[0002] Conventionally, there has been a method for detecting defects on the surface of industrial products using multiple lighting fixtures for visual inspection. Gloss unevenness, where the gloss intensity varies from region to region, is difficult to detect when receiving specularly reflected light directly, but is easily detected when receiving reflected light components close to the specularly reflected light. Patent Document 1 discloses that by using multiple ring lighting devices, captured images suitable for inspecting embossed objects can be obtained. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-32887 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned Patent Document 1, since an image needs to be captured with each of the two ring illuminations, the inspection takes a long time. Furthermore, when the inspection target area is large or when multiple inspection targets are to be inspected at once, the diameter of the ring illumination must be increased in order to capture reflected light close to specular reflection, which may result in reduced inspection accuracy. The present invention provides a technology that enables highly accurate inspection of an inspection area with a single image capture, even when the inspection area is large or multiple inspection areas are inspected simultaneously. [Means for solving the problem]

[0005] One aspect of the present invention comprises a plurality of light sources that irradiate an inspection area with light, an imaging means that images the inspection area irradiated with light by at least some of the plurality of light sources, and an inspection means that performs an inspection of the inspection area based on the captured image obtained by the imaging, wherein the plurality of light sources are arranged in positions such that virtual images corresponding to the light sources surround the inspection area. [Effects of the Invention]

[0006] According to the present invention, even when the inspection area is large or when multiple inspection areas are inspected simultaneously, the inspection area can be inspected with high accuracy by photographing once. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a block diagram showing an example of the hardware configuration of an inspection apparatus. [Figure 2] 2 is a diagram showing an example of the arrangement of an imaging device 111 and a light source device 116. FIG. [Figure 3] FIG. 2 is a block diagram showing an example of the functional configuration of the inspection device 1. [Figure 4] FIG. 2 is a diagram showing the arrangement position of a gloss inspection light source 203-1. [Figure 5] FIG. 2 is a diagram showing a specific example of the first embodiment. [Figure 6] 10 is a flowchart of a process performed by the information processing device 1 to calculate the arrangement position of the gloss inspection light source 203-1. [Figure 7] FIG. 10 is a diagram showing the arrangement of a gloss inspection light source 203-1. [Figure 8] 4 is a flowchart of a process performed by the inspection device to inspect an inspection target. [Figure 9] 1 is a bird's-eye view of the sample surface from directly above the imaging device 111, which is arranged so that four inspection targets arranged on the sample surface fit within the angle of view. [Figure 10] 10 is a flowchart of a process performed by the information processing device 1 to calculate the arrangement position of the gloss inspection light source 203-1. [Figure 11] FIG. 10 is a diagram showing a specific example of step S1006. [Figure 12] FIG. 10 is a bird's-eye view of a configuration in which the gloss inspection light source 203-1 is placed at the placement position determined as the "placement position for placing the gloss inspection light source 203-1" in step S1006. [Figure 13] FIG. 1A is a front view showing an example of the arrangement of a light source for gloss inspection and a light source for color and unevenness inspection, and FIG. 1B is a diagram showing an example of the arrangement of a light source for gloss inspection. [Figure 14] 4 is a flowchart of a process performed by the inspection device to inspect an inspection object. [Figure 15] 10 is a flowchart showing details of the process in step S1401. [Figure 16] FIG. 1 is a diagram showing an example of an inspection target. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0009] [First embodiment] First, an example of the hardware configuration of the inspection device according to this embodiment will be described using the block diagram of Fig. 1. As shown in Fig. 1, the inspection device according to this embodiment includes an information processing device 1, a display device 115, an input device 110, an imaging device 111, a light source device 116, and a storage device 113.

[0010] The CPU 101 executes various processes using computer programs and data stored in the RAM 103. As a result, the CPU 101 controls the overall operation of the information processing device 1 and executes or controls various processes described as processes performed by the information processing device 1.

[0011] The ROM 102 stores setting data for the information processing device 1, computer programs and data related to the startup of the information processing device 1, computer programs and data related to the basic operation of the information processing device 1, and the like.

[0012] The RAM 103 has an area for storing computer programs and data loaded from the ROM 102 or the storage device 113, and an area for storing captured images output from the imaging device 111. The RAM 103 also has a work area used by the CPU 101 when executing various processes. In this way, the RAM 103 can provide various areas as needed.

[0013] A display device 115 is connected to the VC (Video Card) 104. For example, the CPU 101 can output the processing results of the CPU 101 to the display device 115 via the VC 104, thereby displaying the processing results as images, characters, etc. on the display device 115. The display device 115 is a display device having a liquid crystal screen or a touch panel screen. The display device 115 may also be a projection device such as a projector.

[0014] To a general-purpose I / F (interface) 105, an input device 103, an imaging device 111, and a light source device 116 are connected.

[0015] The input device 103 is a user interface such as a keyboard, a mouse, or a touch panel, and allows a user to input various instructions and information to the information processing device 1 by operating it.

[0016] The imaging device 111 is a device provided for capturing an image of an object to be inspected, and may be a still image capturing device that captures still images periodically or irregularly, or a video capturing device that captures video images. The light source device 116 is a device provided for irradiating the object to be inspected with light, and has multiple light sources.

[0017] A storage device 113 is connected to the SATA (Serial ATA) I / F 106. The CPU 101 reads and writes computer programs and data from and to the storage device 113 via the SATA I / F 106.

[0018] The storage device 113 is a non-volatile large-capacity information storage device such as a hard disk drive, etc. The storage device 113 stores an OS, computer programs and data for causing the CPU 101 to execute or control various processes described as processes performed by the information processing device 1, and the like.

[0019] Furthermore, the information processing device 1 can be connected to a network such as a LAN or the Internet via a NIC (network interface card) 107, and can perform data communication with devices on the network. The information processing device 1 may acquire some or all of the information used in each process described below from devices on the network via the NIC 107.

[0020] The CPU 101, ROM 102, RAM 103, VC 104, general-purpose I / F 105, SATA I / F 106, and NIC 107 are all connected to a system bus 108. Note that a computer device such as a PC (personal computer), a smartphone, or a tablet terminal device can be applied to the information processing device 1. The configuration of the inspection device shown in FIG. 1 is merely an example, and for example, a device may be configured by combining two or more of the devices shown in FIG. 1.

[0021] Next, an example of the arrangement of the imaging device 111 and light source device 116 arranged to inspect the gloss, color, and unevenness of an inspection object will be described with reference to Fig. 2. The light source device 116 has a gloss inspection light source 203-1 that irradiates the inspection object with light to inspect the gloss of the inspection object, and a color / unevenness inspection light source 203-2 that irradiates the inspection object with light to inspect the color and unevenness of the inspection object.

[0022] In this embodiment, as shown in FIG. 2 , there are two inspection objects, inspection object 202a and inspection object 202b, placed on the sample surface. A gloss inspection light source 203-1 and a color / unevenness inspection light source 203-2 are arranged to surround these two inspection objects and irradiate the two inspection objects with light. The imaging device 111 simultaneously captures images of the two inspection objects irradiated with light by the gloss inspection light source 203-1 and the color / unevenness inspection light source 203-2 (the imaging device 111 captures images of the two inspection objects while keeping them within the angle of view of the imaging device 111). The information processing device 1 inspects the gloss, color, and unevenness of the two inspection objects from the captured images obtained by the image capture (images in which the two inspection objects are captured simultaneously).

[0023] In this embodiment, an LED is used as the light source in light source device 116, but the type of light source is not limited to a specific type and may be another type of light source, such as a xenon lamp. When inspecting an object using a captured image, it is necessary to change the light irradiation method depending on the appearance inspection items of the object.

[0024] For example, when inspecting the color or unevenness of an object to be inspected, it is necessary to irradiate the surface of the object with light from multiple directions so that specularly reflected light does not penetrate in. Therefore, the light source 203-2 for color / unevenness inspection is arranged in a direction such that the angle between the incident vector of the light irradiating the object to be inspected and the normal vector of the object to be inspected onto which the light is irradiated becomes relatively large (so that diffuse reflection occurs as seen from the imaging device 111).

[0025] For example, when inspecting the gloss of an object, it is necessary to irradiate the surface of the object with light from a direction that allows capturing reflected light close to specular reflection. Therefore, the gloss inspection light source 203-1 is positioned in a direction that makes a relatively small angle between the incident vector of the light irradiating the object and the normal vector of the object onto which the light is irradiated (so that the reflection is close to specular reflection when viewed from the imaging device 111).

[0026] The detailed arrangement of the gloss inspection light source 203-1 will be described later. Images of the object to be inspected illuminated by these light sources from multiple directions are synthesized using a known photometric stereo method to generate an inspection image that includes normal information representing unevenness and color information corresponding to reflectance. The gloss inspection light source 203-1 and the color / unevenness inspection light source 203-2 may each have different light-emitting surfaces and spectral characteristics.

[0027] 3 is a block diagram showing an example of the functional configuration of the inspection device 1. An illumination unit 301 corresponds to the light source device 116, and an imaging unit 302 corresponds to the image capturing device 111. An inspection unit 303 corresponds to a functional unit in the information processing device 1 that is involved in inspecting an object to be inspected.

[0028] The position of the gloss inspection light source 203-1 according to this embodiment will now be described with reference to Fig. 4. Fig. 4(a) is a diagram showing the positional relationship among the gloss inspection light source 203-1, the inspection target 402 placed on the sample surface, and the image capture device 111 installed in the specular reflection direction of light emitted from the gloss inspection light source 203-1 and reflected by the inspection target 402. The image capture device 111 is arranged so that the center of the inspection target 402 is located at the center of the angle of view, that is, in the specular reflection direction of light from the gloss inspection light source 203-1. Here, the position of the foot of the gloss inspection light source 203-1 lowered perpendicularly to the sample surface from position L is defined as Lw.

[0029] The imaging device 111 captures a virtual image 404 corresponding to the gloss inspection light source 203-1 at position L' on a line passing through positions L and Lw. Here, the distance between positions Lw and L' is the same as the distance between positions L and Lw. Regarding virtual images, light rays refracted and reflected by lenses and mirrors do not actually converge into an image, but when the light rays are extended in the opposite direction, they converge to form a kind of image. The light rays have the characteristic of appearing to emanate from a virtual image. An erect image created by a lens or a mirror image created by a plane mirror is a virtual image.

[0030] At this time, the positional relationship between the inspection object 402 and the virtual image 404 as viewed from the imaging device 111 is such that the inspection object 402 and the virtual image 404 overlap, as shown in Fig. 4(b). The image captured by the imaging device 111 in this state corresponds to, for example, an image captured of a plane mirror placed on the sample surface, and the positional relationship between the inspection object 402 and the virtual image 404 in the captured image is the positional relationship shown in Fig. 4(b).

[0031] In Figure 4(c), the arrangement of the imaging device 111 is different from that in Figure 4(a). The imaging device 111 is arranged directly above the inspection object 402, so that the center of the inspection object 402 is located at the center of the angle of view, in order to capture light near the specular reflection light from the gloss inspection light source 203-1 at the inspection object 402.

[0032] At this time, the positional relationship between the inspection object 402 and the virtual image 404 as viewed from the imaging device 111 is as shown in Fig. 4(d), where the position of the virtual image 404 is slightly shifted from the inspection object 402. The image captured by the imaging device 111 in this state corresponds to, for example, an image captured of a plane mirror placed on the sample surface, and the positional relationship between the inspection object 402 and the virtual image 404 in the captured image is as shown in Fig. 4(d).

[0033] In this embodiment, taking these points into consideration, the light source is disposed at a position where a virtual image of the light source surrounds the inspection object as viewed from the imaging device. The process performed by the information processing device 1 to calculate the position of the gloss inspection light source 203-1 will be described with reference to the flowchart in FIG. 6. For specific explanation, the following will be described using an example in which the inspection object is placed at positions C1 and C2 on the sample surface, the gloss inspection light source 203-1 is disposed on a plane (illumination placement plane) at a height ZL from the sample surface, and the imaging device 111 is disposed on a plane (imaging plane) at a height ZC from the sample surface, as shown in FIG. 5. In this embodiment, the gloss inspection light source 203-1 is disposed for each inspection object. The following describes the process for calculating the position of the gloss inspection light source 203-1 for the inspection object disposed at position C1, but similar processes are also performed for the inspection object disposed at position C2.

[0034] Also, in Figure 5, the position of the foot lowered perpendicularly to the sample surface from the center position C of the imaging sensor of the imaging device 111 is position O, and the position of the intersection of the line passing through the center position C and position O with the illumination arrangement surface is position LO.

[0035] In step S601, CPU 101 acquires height ZC (the distance between center position C and position O). The method by which CPU 101 acquires height ZC is not limited to a specific method. For example, CPU 101 may acquire height ZC input by the user operating input device 103, or may acquire height ZC stored in advance in storage device 113. The user can set a desired value for height ZC depending on the size of the inspection object, the size and fineness of the defect, etc.

[0036] In step S602, CPU 101 acquires distance xs (the distance between position O and position C1) in the x-axis direction (the left-right direction on the paper) between center position C and position C1, distance ys (0 in FIG. 5 ) in the y-axis direction (the direction perpendicular to the paper) between center position C and position C1, and size w (the size in the x-axis direction in FIG. 5 ) of the inspection target. The method by which CPU 101 acquires distance xs, distance ys, and size w of the inspection target is not limited to a specific method. For example, CPU 101 may acquire distance xs, distance ys, and size w of the inspection target input by the user through input device 103, or may acquire distance xs, distance ys, and size w of the inspection target stored in advance in storage device 113. Note that distance xs can be set to a desired value by the user in consideration of the size of the inspection target.

[0037] In step S603, CPU 101 acquires height ZL (the distance between position LO and position O). The method by which CPU 101 acquires height ZL is not limited to a specific method. For example, CPU 101 may acquire height ZL input by the user operating input device 103, or may acquire height ZL stored in advance in storage device 113. Note that the user can set a desired value for height ZL.

[0038] In step S604, the CPU 101 calculates CO', which is the sum of the height ZC acquired in step S601 and the height ZL acquired in step S603, according to the following equation (1).

[0039] CO'=ZC+ZL … (1) The surface of the virtual image (virtual image surface) corresponding to the light source arranged on the illumination arrangement surface is a surface located a distance ZL below the sample surface. Here, the intersection point of the virtual image surface and a straight line passing through the center position C and position O is defined as position O'. In this case, CO' calculated by the above formula (1) is the distance between the center position C and position O' (i.e., the distance between the imaging surface and the virtual image surface).

[0040] In step S605, the CPU 101 calculates the placement position on the illumination placement plane of the gloss inspection light source 203-1 that irradiates the inspection object with light. In this embodiment, a case will be described in which N gloss inspection light sources 203-1 are isotropically placed on the illumination placement plane in a circular ring shape (at positions on a circle with a center position CNT on the illumination placement plane and a radius r) relative to the inspection object.

[0041] Here, the intersection position of the straight line passing through the center position C and the position C1 and the virtual image plane is defined as position L1'. At this time, CPU 101 utilizes the fact that triangle CO'L1' and triangle COC1 are similar figures to calculate the distance O'L1' between positions O' and L1' as the x-coordinate of the center position CNT according to the following equation (2).

[0042] x coordinate of the central position CNT = O'L1' = CO' / ZC x xs … (2) The x-coordinate of the center position CNT is, in other words, the distance between the position LO and the x-coordinate of the center position CNT. In the example of FIG. 5, the y-coordinate of the center position CNT is 0. This makes it possible to calculate the position where the virtual image of the center position CNT is placed at the center of the inspection object. Next, the CPU 101 calculates the placement interval Δθ of the N gloss inspection light sources 203-1 according to the following equation (3):

[0043] Δθ=(360-θa) / (N-1) … (3) Here, θa is a value for adjusting the position of the gloss inspection light source 203-1 so that the gloss inspection light source 203-1 is not included in the field of view range of the imaging device 111, and is a value that is set in advance based on the installation conditions of the imaging device 111, etc.

[0044] Here, the position of the right edge of the inspection object is position W, and the position of the virtual image of the gloss inspection light source 203-1 corresponding to the right edge is LW'. At this time, by utilizing the fact that triangle CC1W and triangle CL1'Lw' are similar shapes, CPU 101 calculates the above-mentioned radius r (the distance between position L1' and position LW') according to the following equation 4 so that the virtual image is positioned outside the inspection object.

[0045] r=wx(ZL+ZC) / (2xZC) … (4) Then, the CPU 101 calculates the position (xn, yn) of the nth (1≦n≦N) gloss inspection light source 203-1 among the N gloss inspection light sources 203-1 according to the following equation (5).

[0046] xn=(x coordinate of center position CNT)+cos(θa / 2+(n-1)Δθ) yn = (y coordinate of the central position CNT) + sin(θa / 2 + (n-1)Δθ) ... (Equation 5) Here, position (xn, yn) represents the position of the nth gloss inspection light source 203-1 on the lighting arrangement surface, with position LO as the origin on the lighting arrangement surface, the "left-right direction on the paper surface" as the x-axis direction, and the "direction perpendicular to the paper surface" as the y-axis direction.

[0047] 6, the position of the gloss inspection light source 203-1 suitable for inspecting gloss unevenness is determined, and the user then places the gloss inspection light source 203-1 at the determined position. The resulting position of the gloss inspection light source 203-1 is shown in FIG. 7. FIG. 7 corresponds to the top view of FIG. 2, and in FIG. 7, the black rectangle represents the gloss inspection light source 203-1, and the white rectangle represents a virtual image of the gloss inspection light source 203-1. As shown in FIG. 7, the gloss inspection light source 203-1 is placed so that its virtual image surrounds the object to be inspected when viewed from the position of the image capture device 111, and is installed so that the gloss inspection light source 203-1 does not fall within the angle of view of the image capture device 111.

[0048] The process performed by the inspection device in which the gloss inspection light source 203-1 is placed at the placement position calculated according to the flowchart of FIG. 6 to inspect the inspection object will be described with reference to the flowchart of FIG.

[0049] In step S801, the CPU 101 controls the light source device 116 to control the emission of light by the gloss inspection light source 203-1 and the color / unevenness inspection light source 203-2. In this embodiment, the gloss inspection light source 203-1 is turned on all at once rather than individually, and the color / unevenness inspection light sources 203-2 are turned on one by one.

[0050] In step S802, the CPU 101 controls the imaging device 111 to capture an image of the inspection object in synchronization with the lighting timing of the light sources (the gloss inspection light source 203-1 and the color / unevenness inspection light source 203-2).

[0051] In step S803, the CPU 101 acquires multiple images of the inspection target captured by the imaging device 111 via the general-purpose I / F 105. The CPU 101 then converts each of the acquired images to acquire an RGB image. In this embodiment, the captured images are assumed to be images in the High Efficiency Image File Format (HEIF) format (HEIF images). In this case, the CPU 101 decodes the HEIF images using a known HEIF decoding method. Note that the format of the captured images is not limited to the HEIF format. For example, the captured images may be images in JPEG format or other compressed formats. The CPU 101 then performs degamma processing on the RGB images obtained by the decoding, converting them into RGB images that exhibit a linear relationship with the luminance value. Note that the converted RGB images may also be converted into a predetermined RGB image, such as an sRGB image, using a conversion table based on the characteristics of the imaging device 111.

[0052] In step S804, CPU 101 divides each RGB image obtained by the processing in step S803 into divided images equal in number to the number of inspection objects photographed. In this embodiment, the number of inspection objects photographed at one time is two, so each RGB image is divided into a left half divided image and a right half divided image. Note that the method for dividing the RGB image is not limited to a specific division method, and for example, inspection objects may be extracted from the RGB image and the RGB image may be divided based on the results of the extraction.

[0053] In step S805, CPU 101 repeats the process of step S806 for each segmented image acquired in step S804 in the order of inspection. In step S806, CPU 101 selects one unselected segmented image from all segmented images as a selected segmented image. CPU 101 then performs inspection processing on the inspection target using the selected segmented image. In this embodiment, the inspection processing involves three types of appearance inspection items: color, shape, and gloss. Note that the appearance inspection items are not limited to these. Anything that represents the appearance and can be determined by capturing an image may be used, such as material or pattern. In this embodiment, defects are detected by performing spatial filtering on an inspection image composed of captured images and normal information and color information synthesized using photometric stereo. In this embodiment, CPU 101 integrates the response value of the spatial filtering processing on the inspection image, converts it into a numerical value, and calculates the degree of abnormality.

[0054] In step S807, CPU 101 compares the degree of abnormality calculated in step S806 with a threshold value. If the degree of abnormality is equal to or greater than the threshold value, CPU 101 determines that there is an abnormality (the test result is "fail"), and if the degree of abnormality is less than the threshold value, it determines that there is no abnormality (the test result is "pass"). CPU 101 then causes image or text representing the result of this determination to be displayed on display device 115. Note that the result of this determination is not limited to being displayed on display device 115, and various output methods may be adopted.

[0055] In this manner, in this embodiment, the light source is arranged so that the virtual image of the light source (as seen from the position of the imaging device) on the surface on which the inspection object is placed surrounds the inspection object as seen from the position of the imaging device. Then, the inspection object is photographed in synchronization with the lighting of the light source, and the inspection process is executed sequentially. This allows for highly accurate defect detection of the inspection object.

[0056] In this embodiment, the case where the information processing device 1 performs the processing according to the flowchart in Figure 6 has been described, but this is not limited to this, and other computer devices not included in the inspection device may also perform the processing according to the flowchart in Figure 6.

[0057] <Modification> In the first embodiment, the number of light sources to be arranged is set in advance, and the arrangement positions of the light sources are determined using a preset constant θa so that the light sources are not included in the angle of view of the image capture device 111, as in equation (3). However, the method for preventing the light sources from being included in the angle of view of the image capture device 111 is not limited to this method. For example, if the number of light sources to be arranged is not specified in advance, the arrangement positions of N light sources are calculated using equations (1) to (5) without using the constant θa (assuming θa=0). Then, a configuration may be adopted in which the light sources are arranged at arrangement positions out of the calculated arrangement positions of the image capture device 111 that are not included in the angle of view of the image capture device 111.

[0058] [Second embodiment] In each of the following embodiments and modifications including this embodiment, differences from the first embodiment will be described, and unless otherwise specified below, they will be considered to be the same as the first embodiment. In the first embodiment, a case was described in which an inspection of two inspection objects is performed using images obtained by simultaneously photographing the two inspection objects, but the number of inspection objects is not limited to two. In this embodiment, a case will be described in which an inspection of four inspection objects is performed using images obtained by simultaneously photographing the four inspection objects.

[0059] 9 is a bird's-eye view of the sample surface from directly above the imaging device 111, which is arranged so that four inspection targets (inspection targets 902-1, 902-2, 902-3, and 902-4) arranged on the sample surface fit within the angle of view. Hereinafter, as shown in FIG. 9, the respective arrangement positions of the inspection targets 902-1, 902-2, 902-3, and 902-4 on the sample surface are designated as C1, C2, C3, and C4.

[0060] The process performed by the information processing device 1 to calculate the arrangement position of the gloss inspection light source 203-1 will be described with reference to the flowchart in Fig. 10. In Fig. 10, the same process steps as those in the flowchart in Fig. 6 are assigned the same step numbers as those in the flowchart, and the description of those process steps will be omitted. Note that in this embodiment as well, the processes of steps S601 to S605 are performed for each inspection object.

[0061] In step S1006, the CPU 101 determines, from among the positions calculated in step S605, positions at which the gloss inspection light source 203-1 will not be placed. The processing in step S1006 will be described using a specific example in Fig. 11. In Fig. 11(a), a rectangle arranged on a circumference centered at position C1, a rectangle arranged on a circumference centered at position C2, a rectangle arranged on a circumference centered at position C3, and a rectangle arranged on a circumference centered at position C4 all indicate the positions at which the gloss inspection light source 203-1 is placed calculated in step S605.

[0062] The position 1101 of the gloss inspection light source 203-1 is one of the light sources that cause specular reflection of the inspection object 902-2. However, the position 1109 of the virtual image corresponding to the gloss inspection light source 203-1 at the position 1101 overlaps with the inspection object 902-1, and therefore is a light source that causes specular reflection of another inspection object.

[0063] Similarly, the position 1103 of the gloss inspection light source 203-1 is a light source that causes near-specular reflection for the inspection object 902-4. However, the position 1111 of the virtual image corresponding to the gloss inspection light source 203-1 at the position 1103 overlaps with the inspection object 902-2, and therefore is a light source that causes specular reflection for other inspection objects.

[0064] 11(a), positions 1101 to 1108 are light sources that cause specular reflection of other inspection objects and are not suitable for inspection of the inspection objects. Therefore, in the case of FIG. 11, in step S1006, the CPU 101 determines positions 1101 to 1108 of the placement positions calculated in step S605 as positions where the gloss inspection light source 203-1 will not be placed.

[0065] More specifically, the CPU 101 determines whether the position of the virtual image corresponding to the placement position calculated in step S605 overlaps with the inspection target. As described in the first embodiment, this determination process can be performed using various parameters (such as the position of the image capture device 111, the position of the inspection target, ZL, ZC, and W) shown in FIG. 5 . If the CPU 101 determines that there is overlap as a result of this determination process, it determines the placement position as a “placement position where the gloss inspection light source 203-1 is not placed.” On the other hand, if the CPU 101 determines that there is no overlap as a result of this determination process, it determines the placement position as a “placement position where the gloss inspection light source 203-1 is placed.” The CPU 101 performs this process for each placement position calculated in step S605.

[0066] Fig. 12 shows an overhead view of the configuration in which the gloss inspection light source 203-1 is placed at the placement position determined as the "placement position for placing the gloss inspection light source 203-1" in step S1006. As shown in Fig. 12, the light sources are placed so that each inspection object is surrounded by a virtual image, and light sources that cause specular reflection for other inspection objects are removed.

[0067] In this way, in this embodiment, even if the number of inspection objects is three or more, the light sources can be arranged so that the virtual images of the light sources surround each of the inspection objects, and no light source is arranged that causes specular reflection to other inspection objects. This makes it possible to perform inspection of the inspection objects with high accuracy even if the number of inspection objects is more than two.

[0068] <Modification> In the second embodiment, the case where the number of inspection objects is four has been described, but this is not limiting. For example, if multiple inspection areas are set for one inspection object, the light source can be arranged so that a virtual image of the light source surrounds each inspection area. This is the same as in the first embodiment. In other words, in the above description, the inspection object may be read as "one inspection area set for the inspection object" or "each inspection area set for the inspection object."

[0069] [Third embodiment] In the first and second embodiments, the positions of the light sources suitable for the inspection object (inspection area) are calculated in advance, the light sources are arranged at the positions, and light is emitted from each of the arranged light sources. In this embodiment, the case where the light source that emits light is dynamically determined according to the shape of the inspection area will be described.

[0070] Figure 13(a) shows a front view of an example of the arrangement of the gloss inspection light source and the color / unevenness inspection light source. In Figure 13(a), the black squares are gloss inspection light sources, which are placed on a surface at a specified height (280 mm in Figure 13(a)) from the sample surface. The white rectangles are color / unevenness inspection light sources, which are placed so as to surround the positions C1, C2, and C3 of the inspection targets on the sample surface. The gloss inspection light sources are arranged in a matrix as shown in Figure 13(b) (no gloss inspection light source is placed in the black rectangle in the center), and the gloss inspection light source group is installed so that the plane of the gloss inspection light source group is approximately parallel to the sample surface.

[0071] The processing performed by the inspection device to inspect the inspection object will be described with reference to the flowchart in Fig. 14. In Fig. 14, processing steps that are the same as those shown in Fig. 8 are assigned the same step numbers as those steps, and descriptions of those processing steps will be omitted.

[0072] In step S1401, the CPU 101 selects the gloss inspection light source 203-1 that emits light (turns on) from among the gloss inspection light sources 203-1. Details of the process in step S1401 will be described later.

[0073] In step S1402, the CPU 101 controls the light source device 116 to control the emission of light from the gloss inspection light source 203-1 (the gloss inspection light source 203-1 selected in step S1401) and the color / unevenness inspection light source 203-2.

[0074] Next, details of the processing in step S1401 above will be described with reference to the flowchart in Fig. 15. In Fig. 15, processing steps that are the same as those shown in Fig. 6 are assigned the same step numbers as those steps, and descriptions of those processing steps will be omitted.

[0075] In step S1501, CPU 101 acquires shape information, which is information representing the shape of the inspection area on the inspection surface. For example, the shape information has a flag value corresponding to each position on the sample surface, and the flag value has a value of "1" if the position is within the inspection area and a value of "0" if the position is outside the inspection area.

[0076] The method for acquiring shape information by CPU 101 is not limited to a specific method. For example, CPU 101 may display a list of shape information groups stored in advance in storage device 113 on display device 115, and acquire shape information selected by the user from the displayed list of shape information groups by operating input device 110.

[0077] In step S1505, the CPU 101 initializes the value of a variable i representing a light source number to 0. In this embodiment, it is assumed that each of the arranged gloss inspection light sources 203-1 is assigned a unique light source number.

[0078] In step S1506, the CPU 101 calculates the position of the virtual image corresponding to the gloss inspection light source 203-1 having the light source number corresponding to the value of the variable i, by the method described in the first embodiment (step S605).

[0079] In step S1507, CPU 101 determines the distance between the position of the virtual image calculated in step S1506 and the position of the inspection area represented by the shape information. For example, the coordinates of the upper left corner of an area (i.e., inspection area) that is a collection of positions having a flag value of "1" in the shape information are (xupleft, yupleft), the coordinates of the lower right corner are (xdownright, ydownright), and the position of the virtual image calculated in step S1506 is (xi, yi).

[0080] At this time, if the following formula (6) is satisfied, CPU 101 determines that "the position of the virtual image and the position of the inspection area are close," and if the following formula (6) is not satisfied, CPU 101 determines that "the position of the virtual image and the position of the inspection area are not close."

[0081] (xi-xdownright) 2 +(yi-ydownright) 2 < ε (xi-xupleft) 2 +(yi-yupleft) 2 < ε … (6) Here, ε is a preset threshold value. If it is determined in step S1507 that the position of the virtual image and the position of the inspection area are close to each other, the process proceeds to step S1508, and if it is determined that the position of the virtual image and the position of the inspection area are not close to each other, the process proceeds to step S1510.

[0082] In step S1508, CPU 101 determines whether the position of the virtual image calculated in step S1506 overlaps with the inspection area represented by the shape information, using the following equation (7).

[0083] xupleft <xi<xdownright かつ yupleft<yi<ydownright … (7) If formula (7) is satisfied, it is determined that the position of the virtual image calculated in step S1506 overlaps with the inspection area represented by the shape information, and the process proceeds to step S1510. On the other hand, if formula (7) is not satisfied, it is determined that the position of the virtual image calculated in step S1506 does not overlap with the inspection area represented by the shape information, and the process proceeds to step S1509.

[0084] In step S1509, the CPU 101 selects the gloss inspection light source 203-1 having the light source number corresponding to the value of the variable i as the "gloss inspection light source 203-1 to be irradiated (turned on)."

[0085] In step S1510, the CPU 101 determines whether the value of the variable i is (N-1), that is, whether the processes from step S1506 onward have been performed for all gloss inspection light sources 203-1.

[0086] As a result of this determination, if the value of the variable i is (N-1), that is, if the processes from step S1506 onwards have been performed for all gloss inspection light sources 203-1, the process proceeds to step S1402.

[0087] On the other hand, if the value of variable i is not (N-1), that is, if there are still gloss inspection light sources 203-1 that have not yet been subjected to the processing in step S1506 and subsequent steps, the process proceeds to step S1511. In step S1511, CPU 101 increments the value of variable i by 1. The process then proceeds to step S1506. As described above, in this embodiment, an appropriate light source can be dynamically selected and emitted depending on the shape of the inspection area, enabling inspection to be performed with high accuracy.

[0088] [Fourth embodiment] In the above-described embodiment and modified examples, the inspection object is assumed to be circular and annular illumination is used, but the inspection object does not have to be circular, and the use of annular illumination is not limited. For example, the inspection object may be square as shown in FIG. 16. In this case, the light source may be arranged so that the virtual image of the light source surrounds each inspection object. Furthermore, the inspection object may have a different shape, such as a circle or a square. In this case, the light source may be arranged corresponding to each inspection object.

[0089] The numerical values, processing timing, processing order, processing subject, data (information) configuration / acquisition method / sending destination / sending source / storage location, etc. used in the above embodiments and variant examples are given as examples to provide a concrete explanation, and are not intended to be limited to these examples.

[0090] Furthermore, some or all of the above-described embodiments and modifications may be used in appropriate combination, and some or all of the above-described embodiments may be selectively used.

[0091] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments and modifications to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0092] The invention of this specification includes the following inspection apparatus and inspection apparatus control method. (Item 1) a plurality of light sources for irradiating light onto an inspection area; an imaging means for imaging the inspection area illuminated with light from at least some of the plurality of light sources; an inspection means for inspecting the inspection area based on the photographed image obtained by the photographing; Equipped with The plurality of light sources are arranged at positions where virtual images corresponding to the light sources surround the inspection area. An inspection device characterized by: (Item 2) 2. The inspection device according to item 1, wherein the plurality of light sources are arranged on a circle defined by a position based on the distance between the imaging means and the virtual image, the height of the imaging means, and the position of the inspection area, and a radius based on the height of the light source, the height of the imaging means, and the size of the inspection area. (Item 3) 3. The inspection device according to item 1 or 2, wherein the plurality of light sources are arranged so as not to be included in the angle of view range of the imaging means. (Item 4) 4. The inspection device according to any one of items 1 to 3, wherein the plurality of light sources are arranged for each inspection area such that virtual images corresponding to the light sources surround the inspection area. (Item 5) the imaging means images a plurality of inspection areas illuminated with light from at least some of the plurality of light sources within an angle of view range, The inspection means performs inspection of the inspection areas based on the photographed images including the inspection areas obtained by the photographing. 5. The inspection device according to any one of items 1 to 4. (Item 6) The plurality of light sources are arranged such that, for each inspection area, a virtual image corresponding to the light source is disposed at a position surrounding the inspection area, and the virtual image is not a light source that causes specular reflection with respect to other inspection areas different from the inspection area. 2. The inspection device according to item 1, (Item 7) moreover, 7. The inspection device according to any one of items 1 to 6, further comprising a selection means for selecting, as a light source to irradiate light, a light source from among the plurality of light sources whose virtual image does not overlap with the inspection area, based on information representing the shape of the inspection area. (Item 8) 8. The inspection device according to any one of items 1 to 7, wherein the inspection includes inspection of gloss, color, and unevenness of the inspection area. (Item 9) taking an image of the inspection area illuminated with light from at least some of the light sources that illuminate the inspection area with light, and performing an inspection of the inspection area based on the image obtained by the imaging; The plurality of light sources are arranged at positions where virtual images corresponding to the light sources surround the inspection area. 2. A control method for an inspection apparatus comprising:

[0093] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0094] 301: Lighting section 302: Photography section 303: Inspection section

Claims

1. a plurality of light sources for irradiating light onto an inspection area; an imaging means for imaging the inspection area illuminated with light from at least some of the plurality of light sources; an inspection means for inspecting the inspection area based on the photographed image obtained by the photographing; Equipped with The plurality of light sources are arranged at positions where virtual images corresponding to the light sources surround the inspection area. An inspection device characterized by:

2. 2. The inspection device according to claim 1, wherein the plurality of light sources are arranged on a circle defined by a position based on the distance between the imaging means and the virtual image, the height of the imaging means, and the position of the inspection area, and a radius based on the height of the light source, the height of the imaging means, and the size of the inspection area.

3. 2. The inspection device according to claim 1, wherein the plurality of light sources are arranged so as not to be included in the range of the angle of view of the imaging means.

4. 2. The inspection device according to claim 1, wherein the plurality of light sources are arranged for each inspection area at positions where virtual images corresponding to the light sources surround the inspection area.

5. the imaging means images a plurality of inspection areas illuminated with light from at least some of the plurality of light sources within an angle of view range, The inspection means performs inspection of the inspection areas based on the photographed images including the inspection areas obtained by the photographing.

2. The inspection device according to claim 1.

6. The plurality of light sources are arranged such that, for each inspection area, a virtual image corresponding to the light source is disposed at a position surrounding the inspection area, and the virtual image is not a light source that causes specular reflection with respect to other inspection areas different from the inspection area.

2. The inspection device according to claim 1.

7. moreover, 2. The inspection device according to claim 1, further comprising a selection means for selecting, as a light source to irradiate light, a light source from among the plurality of light sources whose virtual image does not overlap with the inspection area, based on information representing the shape of the inspection area.

8. 2. The inspection device according to claim 1, wherein the inspection includes inspection of gloss, color, and unevenness of the inspection area.

9. taking an image of the inspection area illuminated with light from at least some of the light sources that illuminate the inspection area with light, and performing an inspection of the inspection area based on the image obtained by the imaging; The plurality of light sources are arranged at positions where virtual images corresponding to the light sources surround the inspection area.

2. A control method for an inspection apparatus comprising:

Images