Inspection system

Abstract

To provide an inspection system capable of comparing gloss between ends of an inspection object in a non-destructive manner.SOLUTION: An illumination unit configured to emit light to an irradiated portion of an object to be inspected, a first imaging unit configured to receive reflected light of the light emitted from the illumination unit at the irradiated portion and acquire a first captured image, a second imaging unit configured to receive reflected light of the light emitted from the illumination unit at the irradiated portion and acquire a second captured image, and a first inspection index calculation unit configured to calculate a first inspection index by using a gradation value in a first inspection region in the first captured image; The inspection apparatus includes an index calculation unit configured to calculate a second inspection index using a gradation value in a second inspection region in a second captured image, and an index comparison unit configured to compare the first inspection index and the second inspection index, wherein the first inspection region includes one end portion of the inspection target object in a second direction orthogonal to a first direction, and the second inspection region includes the other end portion of the inspection target object in the second direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, wallpaper has been glued to the walls of a typical room, with each wallpaper lined up widthwise and glued to the wall so that the widthwise edges are butted together, making the boundaries between the wallpaper less visible (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7099053 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when the gloss level differs between adjacent wallpapers, the boundary between the wallpapers becomes conspicuous. Conventionally, when inspecting wallpaper 300, a portion near each of both widthwise ends 301 and 302 of the wallpaper 300 is cut out, as shown in FIG. 12 , and the cutout portions 303 and 304 are positioned so that both ends 301 and 302 are adjacent to each other. An operator then visually compares the cutout portions 303 and 304 to check whether the boundary between both ends 301 and 302 of the wallpaper 300 is conspicuous due to the gloss. This inspection process is time-consuming and labor-intensive, and automation of the inspection process is desirable. Another problem is that the cutout portions 303 and 304 of the wallpaper 300 cannot be used as wallpaper.

[0005] Therefore, an object of the present invention is to provide an inspection system that is capable of comparing gloss between the ends of an object to be inspected non-destructively. [Means for solving the problem]

[0006] One aspect of the present invention for solving the above-mentioned problems is an inspection system that inspects an object to be inspected by moving the object relatively in a first direction, the inspection system comprising: one or more illumination units that irradiate light onto an irradiated portion of the object to be inspected; a first imaging unit that receives light reflected from the irradiated portion of the light irradiated from the illumination unit to acquire a first photographed image; a second imaging unit that receives light reflected from the irradiated portion of the light irradiated from the illumination unit to acquire a second photographed image; an index calculation unit that calculates a first inspection index for a first inspection area in the first photographed image and calculates a second inspection index for a second inspection area in the second photographed image; and an index comparison unit that compares the first inspection index with the second inspection index, wherein the first inspection area includes one end of the object to be inspected in a second direction perpendicular to the first direction, and the second inspection area includes the other end of the object to be inspected in the second direction.

[0007] According to this aspect, a first inspection index is calculated in a first inspection area that includes one end of the object to be inspected using the gradation value of the first inspection area, and a second inspection index is calculated in a second inspection area that includes the other end of the object to be inspected using the gradation value of the second inspection area.Therefore, it is possible to compare both ends of the object to be inspected in the second direction based on the size of the first inspection index and the second inspection index, and the work time can be shortened compared to conventional inspections done by humans. Furthermore, according to this aspect, the first inspection area and the second inspection area are compared using the first captured image and the second captured image, so that the inspection can be performed non-destructively, and the parts belonging to the first inspection area and the second inspection area can also be used as wallpaper.

[0008] A preferred aspect is a first photographing device having a first illumination unit and the first imaging unit, and a second photographing device having a second illumination unit and the second imaging unit, wherein the first imaging unit receives light irradiated from the first illumination unit and reflected from an irradiated portion to obtain a first photographed image, and the second imaging unit receives light irradiated from the second illumination unit and reflected from an irradiated portion to obtain a second photographed image, and the first photographing device and the second photographing device are spaced apart in the second direction.

[0009] In a preferred aspect, an image correction unit is provided that corrects the gradation value of at least one of the first captured image and the second captured image so that the captured images when the same object is captured by the first imaging unit and the second imaging unit are of the same color.

[0010] In a preferred aspect, the index calculation unit calculates the first inspection index using the arithmetic mean values ​​of the R value, G value, and B value of the first inspection area, and calculates the second inspection index using the arithmetic mean values ​​of the R value, G value, and B value of the second inspection area.

[0011] In a preferred aspect, the index calculation unit calculates the first inspection index using the sum of the R value, G value, and B value in the first inspection area, and calculates the second inspection index using the sum of the R value, G value, and B value in the second inspection area.

[0012] In a preferred aspect, the index calculation unit converts the RGB values ​​in the first inspection area into color space data having at least lightness as a spatial axis, and calculates the first inspection index using the lightness value, and converts the RGB values ​​in the second inspection area into color space data having at least lightness as a spatial axis, and calculates the second inspection index using the lightness value.

[0013] In a preferred aspect, the first inspection area is offset from the second inspection area in the first direction.

[0014] In a preferred aspect, the device further includes a determining unit that determines the product as non-defective on the condition that the absolute value of the difference between the first inspection index and the second inspection index is equal to or less than an inspection threshold value.

[0015] In a preferred aspect, the index comparison unit includes a determination unit that determines an abnormality when an absolute value of a difference between the first inspection index and the second inspection index exceeds an inspection threshold value.

[0016] In a preferred aspect, the inspection threshold is set according to the distance between the first inspection area and the second inspection area in the first direction.

[0017] The above aspects may be made dependent on each other, or some of the configurations may be quoted or substituted for each other, as long as they are included in the technical scope of the present invention. [Effects of the Invention]

[0018] According to the present invention, it is possible to compare gloss between the ends of an object to be inspected non-destructively. [Brief explanation of the drawings]

[0019] [Figure 1] 1A and 1B are explanatory diagrams of an inspection object to be inspected by the inspection system of the first embodiment of the present invention, in which (a) is a perspective view of the inspection object, and (b) is a perspective view showing the usage state of the inspection object. [Figure 2] 1 is a perspective view of an inspection system according to a first embodiment of the present invention. [Figure 3] FIG. 3 is a configuration diagram of the inspection system of FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view of the inspection system of FIG. 2. [Figure 5] 3 is a perspective view showing the positional relationship between an inspection object, a line illumination unit, and an imaging unit of the inspection system in FIG. 2. FIG. [Figure 6] FIG. 3 is a partially cutaway perspective view of the line illumination unit of FIG. 2. [Figure 7] FIG. 3 is a partially cutaway perspective view of the imaging unit of FIG. 2. [Figure 8] FIG. 3 is an explanatory diagram showing an example of an image captured by the inspection system of FIG. 2. [Figure 9] 3 is a flowchart showing the operation of the inspection system of FIG. 2 when inspecting an inspection object. [Figure 10] 3 is a cross-sectional perspective view showing a gas flow when an inspection object is inspected in the inspection system of FIG. 2. FIG. [Figure 11] FIG. 10 is an explanatory diagram of an inspection area in an inspection system according to another embodiment of the present invention. [Figure 12] FIG. 1 is an explanatory diagram of a conventional inspection work. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments of the present invention will be described in detail.

[0021] An inspection system 1 according to a first embodiment of the present invention is a quality inspection system that inspects the quality of a sheet-like inspection object 200 such as wallpaper, as shown in FIGS. As shown in Figures 2 and 3, the inspection system 1 has as its main components a management device 2, a photography system 3, and a conveying device 5, and the conveying device 5 moves the inspection object 200 relative to the photography system 3 in a first direction (hereinafter also referred to as the conveying direction T1), so that part or all of the inspection object 200 in the movement direction (conveying direction T1) is photographed by the photography system 3.

[0022] <Inspection object 200> The object to be inspected 200 is a sheet-like body having a planar extension, which is divided into multiple pieces along multiple cutting lines C1 (see FIG. 1(a)) in the longitudinal direction as shown in FIG. 1(b), and is used as divided pieces 210a, 210b. Specifically, the segments 210a and 210b are wallpaper, and are adhered to the wall surface 250 of the room, with the end 202 of segment 210a and the end 203 of the adjacent segment 210b butting against each other as shown in Figure 1(b), so that the segments 210a and 210b do not overlap.

[0023] <Management device 2> The management device 2 is a computer having a hardware configuration including a central processing unit consisting of a control device that controls each device and an arithmetic unit that performs calculations on data, a memory device that stores data, an input device that inputs data from the outside, and an output device that outputs data to the outside. As shown in FIG. 3, the management device 2 includes a data storage unit 10, an image capture unit 11, an area setting unit 12, a data comparison unit 13, an image correction unit 14, and a speed detection unit 15.

[0024] (Data storage unit 10) The data storage unit 10 is a section for storing various data such as past and present captured image data, inspection index data, and comparison result data.

[0025] (Image capture unit 11) The image capturing unit 11 is a part that captures the captured images 110 and 111 captured by the image capturing devices 50 and 51 of the image capturing system 3.

[0026] (Area setting unit 12) The region setting unit 12 is a part that sets a plurality of inspection regions 100 and 101 to be inspected from the photographed images 110 and 111 captured by the image capturing unit 11 . In the area setting unit 12 of this embodiment, as shown in Figure 8, it is possible to set a first inspection area 100 including one end (hereinafter also referred to as the first end 202) in the second direction (hereinafter also referred to as the width direction W) of the object to be inspected 200 from the first photographed image 110 photographed by the first photographing device 50, and a second inspection area 101 including the other end (hereinafter also referred to as the second end 203) in the second direction (width direction W) from the second photographed image 111 photographed by the second photographing device 51. The size of the inspection areas 100, 101 can be set appropriately depending on the size of the inspection object 200. For example, when the inspection object 200 is wallpaper as in this embodiment, the size of the inspection areas 100, 101 is a square as shown in FIG. 2 More than 20cm 2 It is preferable that:

[0027] (Data comparison unit 13) The data comparison unit 13 is a part that identifies the inspection areas 100, 101 set by the area setting unit 12 in the captured images 110, 111 and compares the parts of the inspection object 200 within each inspection area 100, 101, and as shown in Figure 3, it is equipped with an index calculation unit 20, an index comparison unit 21, and a judgment unit 22.

[0028] The index calculation unit 20 is a part that calculates an inspection index related to glossiness using the gradation values ​​of the inspection areas 100, 101 of the captured images 110, 111, and in this embodiment, it is possible to calculate an inspection index related to glossiness of the inspection areas 100, 101 using the gradation values ​​of the inspection areas 100, 101 of the captured images 110, 111. Specifically, the index calculation unit 20 calculates the arithmetic mean value of the R value, G value, and B value for each pixel in each inspection area 100, 101, and calculates the inspection index by using the arithmetic mean value to calculate a whiteness index according to the following formula (1).

[0029] The index calculation unit 20 may calculate the inspection index by calculating the whiteness index using the R value, G value, and B value for each pixel in each inspection area 100, 101 according to the above formula (1) and then calculating the arithmetic mean value of the whiteness index. However, from the viewpoint of reducing the amount of calculation, it is preferable to first calculate the arithmetic mean values ​​of the R value, G value, and B value and then calculate the whiteness index.

[0030] The index comparison unit 21 is a unit that compares the inspection indexes of the inspection areas 100 and 101 calculated by the index calculation unit 20, and compares whether the absolute value of the difference between the inspection indexes of the inspection areas 100 and 101 is equal to or less than the inspection threshold value. The index comparison unit 21 is capable of setting the inspection areas 100, 101 as abnormal areas when the absolute value of the difference between the inspection indexes of the inspection areas 100, 101 exceeds the inspection threshold.

[0031] The determining section 22 is a section that determines whether the inspection object 200 is a non-defective product based on the comparison result of the index comparing section 21.

[0032] (Image correction unit 14) The image correction unit 14 is a part that adjusts the gradation values ​​of the captured images 110, 111 acquired by the image acquisition unit 11 so that the captured images of the same subject photographed by the first imaging unit 62a of the first photographing device 50 and the second imaging unit 62b of the second photographing device 51 are of the same color.

[0033] (Speed ​​detection unit 15) The speed detection unit 15 is a part that detects the speed at which the transport device 5 transports the inspection object 200 .

[0034] <Shooting System 3> As shown in FIG. 3, the imaging system 3 includes a plurality of imaging devices 50, 51 and a gas supply unit 52, and images of an inspection object 200 are taken by the imaging devices 50, 51.

[0035] (Photography devices 50, 51) As shown in FIG. 4, the photographing devices 50 and 51 include a line illumination unit 61 and an imaging unit 62 in a housing unit 60. As shown in Figures 2 and 4, the housing 60 is a box-shaped body having a bottom wall 70, a top wall 71, and peripheral walls 72 to 75, and has an internal storage space 76 surrounded by the walls 70 to 75. The housing 60 has an opening 77 in the bottom wall 70 that connects the inside and outside of the storage space 76 . The opening 77 is a through-hole that penetrates the bottom wall portion 70 in the thickness direction, and is a through-groove that has a width in the transport direction T1 and extends in the width direction W of the inspection object 200 as shown in FIG.

[0036] As shown in Figure 6, the line illumination unit 61 has one or more light source units 80 and a focusing lens unit 81, and is capable of irradiating a line of line light extending in the width direction W (second direction) onto the irradiated portion 201 of the object to be inspected 200, as shown in Figure 5.

[0037] As shown in FIG. 6, the light source sections 80 are arranged in a straight line at intervals in the width direction W (main scanning direction). The light source unit 80 is specifically an LED chip, and is capable of emitting light having directivity in one direction.

[0038] The condenser lens section 81 is a section that condenses and emits light incident from each light source section 80, and is a lens whose longitudinal direction extends in the width direction W as shown in FIG. That is, in the line illumination unit 61, light emitted from a plurality of light source units 80 is combined into a line-shaped light by the condenser lens unit 81 and then emitted.

[0039] As shown in FIG. 7, the imaging unit 62 is an elongated portion extending in the width direction W (main scanning direction), and includes an imaging lens unit 90 and a light receiving element substrate 91. The imaging lens section 90 is a section that transmits light reflected from an irradiated section 201 (see FIG. 4) of the inspection object 200 and forms an image on the light receiving elements 95 of each light receiving element substrate 91. As shown in FIG. 7, the light receiving element substrate 91 has a plurality of light receiving elements 95, which are arranged in a straight line in the width direction W. The light receiving element substrate 91 is capable of converting the light focused by the imaging lens unit 90 into an electrical signal according to the amount of received light by photoelectric conversion of the light received by each light receiving element 95 .

[0040] (gas supply unit 52) As shown in FIG. 10, the gas supply unit 52 is a part that supplies gas into the housing unit 60 and creates a positive pressure inside the housing unit 60. The gas is not particularly limited as long as it does not react with the inspection target 200, but for example, compressed air or an inert gas such as nitrogen or a rare gas such as argon can be used.

[0041] <Transportation device 5> As shown in FIG. 2, the transport device 5 includes a plurality of transport rollers 120a to 120d, and is capable of transporting the inspection object 200 in a transport direction T1 by rotating the transport rollers 120a to 120d using a drive source (not shown). The conveying rollers 120b, 120c adjacent to the photography system 3 are support rollers that support the inspection object 200 from the vertically downward side (the opposite side to the opening 77), as shown in Figure 4, and are capable of supporting the inspection object 200 so that the top surface thereof is horizontal. Conveying roller 120a, which is adjacent to conveying roller 120b on the downstream side, and conveying roller 120d, which is adjacent to conveying roller 120c on the upstream side, are pushing rollers that push the object to be inspected 200 downward, and are tensioning members that apply tension to the object to be inspected 200.

[0042] Next, the positional relationship between the components of the inspection system 1 of this embodiment will be described.

[0043] 2 and 5, in the inspection system 1, the image capturing devices 50 and 51 are arranged side by side at an interval in the width direction W of the inspection object 200. That is, the housing 60 of the first image capturing device 50 and the housing 60 of the second image capturing device 51 are spaced apart in the width direction W. As shown in Figure 5, the first photographing device 50 is arranged so that the irradiated portion 201a by the line light irradiated from each light source unit 80 of the first line illumination unit 61a (first illumination unit) straddles a first end 202 in the width direction W of the object to be inspected 200, and the second photographing device 51 is arranged so that the irradiated portion 201b by the line light irradiated from each light source unit 80 of the second line illumination unit 61b (second illumination unit) straddles a second end 203 in the width direction W of the object to be inspected 200. As shown in Figure 4, the photographing devices 50, 51 have line illumination units 61a, 61b arranged upstream of the irradiated portion 201 of the object to be inspected 200 in the conveying direction T1, and photographing units 62a, 62b arranged downstream. When viewed from the width direction W, the line illumination unit 61 is positioned symmetrically with the imaging unit 62 with respect to a virtual line P1 perpendicular to the irradiated portion 201 of the object to be inspected 200, and the imaging unit 62 is positioned so that it can mainly receive the specularly reflected light of the light irradiated from the line illumination unit 61 at the irradiated portion 201 of the object to be inspected 200.

[0044] As shown in Figure 4, the optical axis L1 (incident axis) of the light irradiated from the line illumination unit 61, when viewed from the width direction W of the object to be inspected 200, is inclined at an inclination angle θ1 toward the upstream side of the conveying direction T1 with respect to a virtual line P1 perpendicular to the irradiated portion 201 of the object to be inspected 200. The inclination angle θ1 (incidence angle to the irradiated portion 201 of the inspection object 200) of the optical axis L1 shown in Figure 4 with respect to the virtual line P1 is preferably 20 degrees or more, more preferably 45 degrees or more, and even more preferably 60 degrees or more. The tilt angle θ1 of the optical axis L1 shown in FIG. 4 relative to the imaginary line P1 is less than 90 degrees, preferably 85 degrees or less, and more preferably 80 degrees or less.

[0045] The imaging axis L2 of the imaging unit 62 (the optical axis of the reflected light received by the light receiving element 95) is inclined at an inclination angle θ2 toward the downstream side in the conveying direction T1 with respect to a virtual line P1 perpendicular to the irradiated portion 201 of the inspection object 200 when viewed from the width direction W of the inspection object 200. The tilt angle θ2 (light receiving angle of the light receiving element 95) of the imaging axis L2 shown in FIG. 4 relative to the virtual line P1 is preferably 20 degrees or more, more preferably 45 degrees or more, and even more preferably 60 degrees or more. The tilt angle θ2 of the imaging axis L2 shown in FIG. 4 with respect to the virtual line P1 is less than 90 degrees, preferably 85 degrees or less, and more preferably 80 degrees or less. The difference between the tilt angle θ2 (light receiving angle) of the imaging axis L2 with respect to the virtual line P1 shown in FIG. 4 and the tilt angle θ1 (incident angle) of the optical axis L1 with respect to the virtual line P1 is preferably within 5 degrees, and more preferably within 3 degrees.

[0046] As shown in FIG. 4, the opening 77 of the housing 60 faces the irradiated portion 201 of the inspection object 200 in the vertical direction, and the housing 60 is positioned above the inspection object 200 in the vertical direction. The shortest distance D1 between the opening 77 of the housing part 60 shown in Figure 4 and the irradiated part 201 of the object to be inspected 200 is preferably more than 0 mm and not more than 50 mm, and more preferably not less than 10 mm from the viewpoint of preventing contact of the object to be inspected 200 with the housing part 60.

[0047] The distance D2 between the imaging lens section 90 of the imaging section 62 and the irradiated section 201 of the inspection object 200 shown in FIG. 4 is preferably 20 mm or more, and more preferably 30 mm or more. The distance D2 between the imaging lens section 90 of the imaging section 62 and the irradiated section 201 of the inspection object 200 is preferably 100 mm or less, and more preferably 75 mm or less.

[0048] The inspection object 200 is suspended between the transport rollers 120a to 120d, and the portion suspended between the transport rollers 120b and 120c is in a horizontal position, i.e., it is parallel to and faces the opening 77 of the housing 60 with a gap therebetween.

[0049] Next, the operation of the inspection system 1 when inspecting the inspection target 200 using the inspection system 1 of this embodiment will be described with reference to the flowchart of FIG.

[0050] First, the inspection areas 100, 101 to be compared with the inspection object 200 are set by the area setting unit 12 of the management device 2 (step S1-1). For example, as shown in FIG. 8, the region setting unit 12 sets regions including both end portions 202 and 203 in the width direction W of the inspection object 200 as inspection regions 100 and 101.

[0051] Next, while the transport device 5 transports the inspection object 200 in the transport direction T1, the imaging system 3 photographs the irradiated portion 201 of the inspection object 200, and the management device 2 starts an inspection operation to inspect the inspection object 200 (step S1-2).

[0052] In the inspection operation, first, the photographing system 3 performs a photographing operation in which the first photographing device 50 photographs an image 110 of the object to be inspected 200 so that the image 110 includes the first end 202 in the width direction W of the object to be inspected 200, and the second photographing device 51 photographs an image 111 of the object to be inspected 200 so that the second end 203 in the width direction W of the object to be inspected 200 is included. 5, line light is emitted from each light source unit 80 of the line illumination units 61a and 61b of each imaging device 50 and 51 of the imaging system 3 to the irradiated portions 201a and 201b of the inspection object 200, and specularly reflected light from the irradiated portions 201a and 201b is received by each light receiving element 95 of each imaging unit 62a and 62b. In this state, the inspection object 200 is moved in the conveying direction T1 by the conveying device 5.

[0053] At this time, when the specularly reflected light is received by each light receiving element 95 of the imaging units 62a and 62b, the specularly reflected light is photoelectrically converted into an electrical signal and transmitted to the management device 2. Then, the management device 2 uses the image capture unit 11 to capture the electrical signal as captured images 110 and 111.

[0054] At this time, the housing 60 is filled with gas supplied by the gas supply unit 52 and is under positive pressure, and the gas is injected from the opening 77 toward the irradiated portion 201 of the inspection object 200 as shown by the arrow in Fig. 10. That is, the imaging devices 50, 51 of this embodiment perform imaging in a state in which gas is constantly being injected from the opening 77 toward the irradiated portion 201 of the inspection object 200 during imaging operation. Therefore, impurities such as dust on the irradiated portion 201 of the inspection object 200 are constantly pushed out by the gas.

[0055] Next, the management device 2 adjusts the gradation values ​​of the captured images 110, 111 using the image correction unit 14 as necessary, the area setting unit 12 identifies the inspection areas 100, 101 in the captured images 110, 111, the index calculation unit 20 of the data comparison unit 13 calculates the inspection index for each inspection area 100, 101 from the captured images 110, 111, and the index comparison unit 21 compares the first inspection index of the first inspection area 100 with the second inspection index of the second inspection area 101 and determines whether the absolute value of the difference between the first inspection index of the first inspection area 100 and the second inspection index of the second inspection area 101 is below the inspection threshold (step S1-4).

[0056] The inspection threshold at this time may be a constant, or may be a variable that varies depending on the positional relationship between the inspection areas 100 and 101. For example, when the distance between the inspection areas 100 and 101 in the transport direction T1 is short, the inspection threshold can be set to a small value, and when the distance between the inspection areas 100 and 101 in the transport direction T1 is long, the inspection threshold can be set to a large value. When the inspection threshold is a constant, it is preferable that the inspection threshold is not less than 0.05% and not more than 1.3% of the full scale. When the inspection areas 100 and 101 are attached adjacent to each other to the wall surface 250 as in this embodiment (FIG. 1), the inspection threshold can be set to a small value. Furthermore, it is preferable that each inspection index is calculated by identifying the portion in the photographed images 110, 111 where the inspection object 200 exists, and using only the gradation values ​​(RGB values) of the portion where the inspection object 200 exists. That is, it is preferable that the whiteness index is calculated as the inspection index by using the arithmetic mean values ​​of the R value, G value, and B value of each pixel in the portion in the photographed images 110, 111 where the inspection object 200 exists.

[0057] If the difference in inspection index between the inspection areas 100, 101 is equal to or less than the inspection threshold (Yes in step S1-4), it is checked whether there is a request to end the inspection operation due to the end of inspection of the inspection object 200, etc. (step S1-5).

[0058] If there is a request to end the inspection (Yes in step S1-5), the inspection operation is ended, and it is checked whether an abnormal area has been detected in the captured images 110, 111 (step S1-6).

[0059] If no abnormal region is detected in the entire inspection object 200, the inspection object 200 is determined to be a non-defective product (step S1-7).

[0060] On the other hand, in step S1-4, if the difference in inspection index between the inspection areas 100, 101 exceeds the inspection threshold (No in step S1-4), the judgment unit 22 determines that there is a difference in glossiness between the inspection areas 100, 101 and that this is abnormal, sets the inspection areas 100, 101 as abnormal areas (step S1-8), and proceeds to step S1-5.

[0061] At this time, if the inspection system 1 cooperates with a manufacturing device for the inspection object 200, the abnormal area may be feedback-controlled to the manufacturing device for the inspection object 200 when the abnormal area is set, as necessary.

[0062] Furthermore, in step S1-5, if a request to end the inspection operation is not confirmed (step S1-5), the process proceeds to step S1-4.

[0063] If an abnormal region is found in the inspection object 200 in step S1-6 (No in step S1-6), the process proceeds to step S1-9, where the inspection object is determined to be a defective product.

[0064] According to the inspection system 1 of this embodiment, the photographing devices 50, 51 have, in a housing 60, a line illumination unit 61 that irradiates a line light extending in the width direction W onto an irradiated portion 201 of the inspection object 200, and an imaging unit 62 that receives reflected light of the line light irradiated from the line illumination unit 61 at the irradiated portion 201 to obtain photographed images 110, 111 of the inspection object 200, and when viewed from the width direction W, the line illumination unit 61 is disposed upstream in the conveying direction T1 of a virtual line P1 that is perpendicular to the irradiated portion 201, and the imaging unit 62 is disposed downstream in the conveying direction T1 of the virtual line P1. This makes it possible to reproduce a situation in which a person is looking at the inspection object 200 with oblique light, and photograph the inspection object 200 so that the gloss of the inspection object 200 is reflected in the photographed images 110, 111. Furthermore, according to the inspection system 1 of this embodiment, the imaging devices 50 and 51 have an imaging section 62 having a plurality of light receiving elements 95 arranged in the width direction W, and light reflected from the irradiated portion 201 can be received by each of the light receiving elements 95. Therefore, imaging can be performed under uniform conditions in the width direction W.

[0065] In the inspection system 1 of this embodiment, when the photographing devices 50 and 51 are viewed from the width direction W, it is preferable that the angle θ2 of the imaging axis L2 of the imaging unit 62 with respect to the virtual line P1 is equal to or greater than 60 degrees and less than 90 degrees. This allows the gloss of the inspection object 200 to be more effectively reflected in the photographed images 110 and 111.

[0066] In the inspection system 1 of this embodiment, when viewed from the width direction W, the difference between the angle θ2 of the imaging axis L2 of the imaging unit 62 with respect to the virtual line P1 and the angle θ1 of the incident axis (optical axis L1) of the line light irradiated from the line illumination unit 61 with respect to the virtual line P1 is preferably 3 degrees or less. This makes it possible to extract a large amount of the specularly reflected light component from the irradiated portion 201, and to better reflect the gloss of the inspection object 200 in the captured images 110 and 111.

[0067] In the inspection system 1 of this embodiment, the imaging unit 62 preferably has a plurality of imaging lens units 90 and a light receiving element 95 that receives reflected light that has passed through each imaging lens unit 90, and the plurality of imaging lens units 90 are preferably arranged in a straight line in the width direction W. This allows imaging to be performed under approximately uniform conditions at any position in the width direction W.

[0068] In the inspection system 1 of this embodiment, the shortest distance D1 between the housing 60 and the irradiated portion 201 of the imaging devices 50 and 51 is greater than 0 mm and equal to or less than 50 mm. This allows the images 110 and 111 to be captured without being too far away from the inspection object 200 and without contacting the inspection object 200.

[0069] In the inspection system 1 of this embodiment, the photographing system 3 has a first photographing device 50 and a second photographing device 51, and is capable of performing a photographing operation in which the first photographing device 50 photographs an image 110 of the inspection object 200 so as to include a first end 202 which is one end in the width direction W of the inspection object 200, and the second photographing device 51 photographs an image 111 of the inspection object 200 so as to include a second end 203 which is the other end in the width direction W of the inspection object 200. Therefore, when a plurality of inspection objects 200 are arranged in the width direction W, such as wallpaper, as in this embodiment, it is possible to determine the extent of gloss difference between the inspection objects 200.

[0070] The inspection system 1 of this embodiment preferably includes an imaging system 3, a conveying device 5 that moves the inspection object 200 in the conveying direction T1, an image capturing unit 11 that acquires a first captured image 110 captured by the first imaging device 50 and a second captured image 111 captured by the second imaging device 51, and a data comparison unit 13 that compares the captured images 110, 111 captured by the image capturing unit 11. This makes it possible to automatically compare the first captured image 110 captured by the first imaging device 50 and the second captured image 111 captured by the second imaging device 51.

[0071] According to the inspection system 1 of this embodiment, the imaging devices 50, 51 include a housing 60 having an opening 77, a gas supply unit 52 capable of supplying gas into the housing 60 and injecting the gas onto the inspection object 200 through the opening 77, and an imaging operation in which, with the gas supply unit 52 injecting gas onto the inspection object 200, the line illumination unit 61 irradiates the irradiated portion 201 of the inspection object 200 with line light that has passed through the opening 77, and the imaging unit 62 receives the light reflected from the irradiated portion 201 that has passed through the opening 77. Therefore, even if impurities such as dust are attached to the irradiated portion 201 of the inspection object 200, the impurities can be removed by injecting the gas. Furthermore, since the interior of the housing 60 is filled with gas when the imaging operation is performed, impurities such as dust can be prevented from entering the interior of the housing 60 through the opening 77. As a result, impurities such as dust are less likely to appear in the captured images 110, 111 than in the past. Furthermore, according to the inspection system 1 of this embodiment, the opening 77 extends in the direction in which the line light extends (width direction W), and gas can be blown onto the inspection object 200 in a direction intersecting the transport direction T1 of the inspection object 200, making it possible to photograph the entire irradiated area 201 while removing impurities such as dust.

[0072] In the inspection system 1 of this embodiment, it is preferable that the openings 77 of the imaging devices 50, 51 face the irradiated portion 201 of the inspection object 200 with a gap therebetween. This allows the gas to be directly sprayed onto impurities such as dust adhering to the irradiated portion 201 of the inspection object 200, making it easier to remove impurities such as dust from the irradiated portion 201 of the inspection object 200.

[0073] In the inspection system 1 of this embodiment, the shortest distance D2 between the opening 77 and the irradiated portion 201 during the photographing operation of the photographing devices 50 and 51 is more than 0 mm and not more than 50 mm. Therefore, gas can be forcefully sprayed from the opening 77 onto the irradiated portion 201 of the inspection object 200.

[0074] In the inspection system 1 of this embodiment, the gas supplied from the gas supply unit 52 is preferably compressed air or an inert gas. This makes it possible to create a positive pressure inside the housing unit 60 and safely remove impurities such as dust from the inspection target object 200.

[0075] The inspection system 1 of this embodiment includes an imaging device 50 and a conveying device 5 that moves the inspection object 200 in the conveying direction T1, the inspection object 200 being a sheet-like body having a length in the conveying direction T1, and the conveying device 5 preferably includes conveying rollers 120b and 120c that support the inspection object 200 so that the irradiated portion 201 faces the opening 77, and conveying rollers 120a and 120d that apply tension to the inspection object 200. In this way, the inspection object 200 can be photographed while tension is always applied, and even if gas is blown onto the inspection object 200, the inspection object 200 is less likely to bend, and the captured images 110 and 111 are less likely to be distorted.

[0076] According to the inspection system 1 of this embodiment, there are provided line illumination units 61a and 61b that irradiate light onto the irradiated portion 201 of the inspection object 200, a first image capturing unit 62a that receives the light irradiated from the first line illumination unit 61a and reflected by the irradiated portion 201 to obtain a first captured image 110, a second image capturing unit 62b that receives the light irradiated from the second line illumination unit 61b and reflected by the irradiated portion 201 to obtain a second captured image 111, and a second image capturing unit 62c that captures the second captured image 111 in the first captured image 110. The inspection device includes an index calculation unit 20 that calculates a first inspection index in a first inspection area 100 and calculates a second inspection index in a second inspection area 101 in a second captured image 111, and an index comparison unit 21 that compares the first inspection index with the second inspection index, wherein the first inspection area 100 includes a first end 202 of the inspection object 200 in a width direction W perpendicular to the conveying direction T1, and the second inspection area 101 includes a second end 203 of the inspection object 200 in the width direction W. That is, according to the inspection system 1 of this embodiment, the first inspection index is calculated using the gradation value in the first inspection area 100, and the second inspection index is calculated using the gradation value in the second inspection area 101, so that the comparison between the first inspection area 100 and the second inspection area 101 can be automatically determined based on the size of the inspection index, and the work time can be shortened compared to conventional manual inspection. Furthermore, according to the inspection system 1 of this embodiment, the first inspection area 100 and the second inspection area 101 are compared using the first captured image 110 and the second captured image 111 captured by each of the photographing devices 50 and 51, so that the inspection can be performed non-destructively, and the parts belonging to the inspection areas 100 and 101 can also be used as wallpaper. Furthermore, in the case where one inspection object 200 is divided into multiple divided pieces 210a, 210b as in this embodiment, and multiple divided pieces 210a, 210b are arranged side by side in the width direction W, it is possible to determine whether a gloss difference occurs between adjacent divided pieces 210a, 210b.

[0077] The inspection system 1 of this embodiment includes a first photographing device 50 having a first line illumination unit 61a and a first imaging unit 62a, and a second photographing device 51 having a second line illumination unit 61b and a second imaging unit 62b, and the first photographing device 50 and the second photographing device 51 are spaced apart in the width direction W. That is, the first photographing image 110 including the first inspection area 100 and the second photographing image 111 including the second inspection area 101 are photographed by the independent photographing devices 50, 51, respectively, so that even if the width of the inspection target 200 is large, inspection can be performed.

[0078] In the inspection system 1 of this embodiment, it is preferable to provide an image correction unit 14 that corrects the gradation value of at least one of the first captured image 110 and the second captured image 111 so that the captured images of the same object captured by the first imaging unit 62a and the second imaging unit 62b have the same color. In this way, the captured images 110, 111 can be normalized by the image correction unit 14, so that the inspection indices can be compared even if the captured images 110, 111 are captured by different imaging devices 50, 51.

[0079] In the inspection system 1 of this embodiment, it is preferable that the index calculation unit 20 calculates the first inspection index using the arithmetic mean values ​​of the R, G, and B values ​​of the first inspection area 100, and calculates the second inspection index using the arithmetic mean values ​​of the R, G, and B values ​​of the second inspection area 101. That is, it is preferable to calculate the inspection index in advance using the arithmetic mean values ​​of the R, G, and B values ​​in the captured images 110, 111. This can reduce the amount of calculation compared to calculating the inspection index for each pixel in each inspection area 100, 101 and then calculating the average of the inspection indices.

[0080] In the inspection system 1 of this embodiment, it is preferable that the index calculation unit 20 calculates the first inspection index using the sum of the R value, G value, and B value in the first inspection area 100, and calculates the second inspection index using the sum of the R value, G value, and B value in the second inspection area 101. In this way, the degree of glossiness between the inspection areas 100 and 101 can be easily determined from the captured images 110 and 111 without performing image conversion processing or the like.

[0081] In the inspection system 1 of this embodiment, the first inspection area 100 is preferably shifted in the transport direction T1 with respect to the second inspection area 101. In the case where one inspection object 200 is divided into a plurality of divided pieces 210a, 210b and the divided pieces 210a, 210b are arranged side by side in the width direction W as in this embodiment, by setting the first inspection area 100 and the second inspection area 101 to be arranged side by side in the width direction W when installed, it is possible to more accurately determine whether a gloss difference occurs between adjacent divided pieces 210a, 210b.

[0082] In the inspection system 1 of this embodiment, it is preferable that the judgment unit 22 judges the object to be inspected 200 as non-defective if the absolute value of the difference between the first inspection index and the second inspection index is equal to or less than the inspection threshold value. This makes it possible to quantitatively judge whether the object to be inspected 200 is good or bad.

[0083] In the inspection system 1 of this embodiment, it is preferable that the judgment unit 22 judges an abnormality when the absolute value of the difference between the first inspection index and the second inspection index exceeds the inspection threshold value. In this way, an abnormal area in a defective product can be identified, and the product can be used as a non-defective product by removing the part corresponding to the abnormal area.

[0084] In the inspection system 1 of this embodiment, the inspection threshold is preferably set according to the distance in the transport direction T1 between the first inspection area 100 and the second inspection area 101. In this way, the inspection threshold can be set in accordance with the allowable change in gloss.

[0085] In the above embodiment, the index calculation unit 20 calculates the whiteness index as the inspection index, but the present invention is not limited to this. The index calculation unit 20 may calculate the inspection index by other methods using RGB values ​​in the inspection areas 100, 101 in the captured images 110, 111 acquired by the imaging units 62a, 62b. For example, the index calculation unit 20 may convert the RGB values ​​in the inspection areas 100 and 101 into color space data with at least brightness as the spatial axis, and calculate the inspection index using the brightness value. Specifically, the inspection index may be calculated by converting the arithmetic mean value of the RGB values ​​of each pixel in each inspection area 100, 101 in the captured images 110, 111 into the L*a*b* color space of CIE 1976 and calculating the L* value representing lightness. That is, the inspection index calculated by the index calculation unit 20 may be the L* value in the L*a*b* color system. By doing so, the glossiness of the inspection areas 100 and 101 can be determined more accurately. The method for converting RGB values ​​into the CIE1976 L*a*b* color space is not particularly limited, but for example, conversion can be performed using a library such as the Open Source Computer Vision Library using Python. In addition, the index calculation unit 20 may calculate the inspection index by converting the RGB values ​​of each pixel of each inspection area 100, 101 in the captured images 110, 111 into the CIE1976 L*a*b* color space and calculating the arithmetic mean value of the L* value, which represents lightness.

[0086] In these cases, the inspection threshold used in the comparison between the inspection areas 100, 101 by the index comparing unit 21 may be a constant, as in the above-described embodiment, or may be a variable that varies depending on the positional relationship between the inspection areas 100, 101.

[0087] In the above embodiment, the index calculation unit 20 calculates the inspection index using the RGB values ​​of the inspection areas 100, 101 of the photographed images 110, 111, but the present invention is not limited to this. The index calculation unit 20 may calculate the inspection index using the grayscale gradation values ​​of the inspection areas 100, 101 of the photographed images 110, 111.

[0088] In the above embodiment, the inspection areas 100, 101 are set to be shifted in the transport direction T1 so that they are adjacent to each other when attached to the wall surface 250, but the present invention is not limited to this. As shown in Figure 11, the inspection areas 100, 101 may be set to be at the same position in the transport direction T1.

[0089] In the above-described embodiment, the line illumination unit 61 is arranged upstream of the imaging unit 62 in the conveying direction T1, but the present invention is not limited to this. The line illumination unit 61 may be arranged downstream of the imaging unit 62 in the conveying direction T1. That is, the photographing devices 50, 51 may be arranged such that the imaging unit 62 is arranged upstream of the irradiated portion 201 of the inspection object 200 in the conveying direction T1, and the line illumination unit 61 is arranged downstream.

[0090] In the above-described embodiment, the image capturing devices 50, 51 are oriented such that the opening 77 of the housing 60 faces vertically, but the present invention is not limited to this. The image capturing devices 50, 51 may be oriented such that the opening 77 of the housing 60 faces in a direction other than vertical.

[0091] In the above embodiment, the inspection object 200 is moved relative to the imaging system 3 by the conveying device 5, but the present invention is not limited to this. The imaging system 3 may be moved relative to the inspection object 200.

[0092] In the above embodiment, the photographing system 3 photographs the inspection object 200 using the two photographing devices 50 and 51, but the present invention is not limited to this. The photographing system 3 may photograph the inspection object 200 using one photographing device, or may photograph the inspection object 200 using three or more photographing devices.

[0093] In the above embodiment, the inspection object 200 is wallpaper, but the present invention is not limited to this. The inspection object 200 may be, for example, a solar cell module, a residential interior material, an exterior wall material, a floor material, a ceiling material, or the like.

[0094] In the above embodiment, the conveying device 5 directly conveys the inspection object 200 in the conveying direction T1, but the present invention is not limited to this. The conveying device 5 may convey the inspection object 200 in the conveying direction T1 via a conveying sheet such as a conveyor belt or a conveying chain.

[0095] In the above embodiment, the axial direction of the optical axis L1 of the light irradiated from the line illumination unit 61 is different from the axial direction of the imaging axis L2 of the imaging unit 62, but the present invention is not limited to this. The axial direction of the optical axis L1 of the light irradiated from the line illumination unit 61 may be the same as the axial direction of the imaging axis L2 of the imaging unit 62.

[0096] In the above-described embodiments, each component can be freely substituted or added between the respective embodiments as long as it falls within the technical scope of the present invention. [Explanation of symbols]

[0097] 1. Inspection system 20 Index calculation part 22 Judgment section 21 Exponential Comparison Unit 61, 61a, 61b Line lighting unit (lighting unit) 62, 62a, 62b Imaging unit 100 First Inspection Area 101 Second Inspection Area 200, 200a, 200b Inspection object 201,201a,201b Irradiated area 202 First end (one end) 203 Second end (other end)

Claims

1. An inspection system that inspects an inspection object by relatively moving the inspection object in a first direction, one or more illumination units that irradiate light onto an irradiated portion of the inspection object; a first imaging unit that receives light irradiated from the illumination unit and reflected by the irradiated unit to obtain a first captured image; a second imaging unit that receives light irradiated from the illumination unit and reflected by the irradiated unit to obtain a second captured image; an index calculation unit that calculates a first inspection index using a gradation value in a first inspection area in the first captured image and calculates a second inspection index using a gradation value in a second inspection area in the second captured image; an index comparison unit that compares the first inspection index with the second inspection index; the first inspection area includes one end of the inspection object in a second direction perpendicular to the first direction, An inspection system, wherein the second inspection area includes the other end of the inspection object in the second direction.

2. a first photographing device having a first illumination unit and the first imaging unit, and a second photographing device having a second illumination unit and a second imaging unit; the first imaging unit receives light irradiated from the first illumination unit and reflected by an irradiated portion to acquire a first captured image; the second imaging unit receives light irradiated from the second illumination unit and reflected by an irradiated portion to acquire a second captured image; The inspection system of claim 1 , wherein the first and second image capture devices are spaced apart in the second direction.

3. 3. The inspection system according to claim 2, further comprising an image correction unit that corrects the gradation value of at least one of the first captured image and the second captured image so that the captured images of the same object captured by the first imaging unit and the second imaging unit have the same color.

4. 2. The inspection system of claim 1, wherein the index calculation unit calculates the first inspection index using arithmetic mean values ​​of R values, G values, and B values ​​of the first inspection area, and calculates the second inspection index using arithmetic mean values ​​of R values, G values, and B values ​​of the second inspection area.

5. The inspection system according to any one of claims 1 to 4, wherein the index calculation unit calculates the first inspection index using a total value of the R value, the G value, and the B value in the first inspection area, and calculates the second inspection index using a total value of the R value, the G value, and the B value in the second inspection area.

6. The inspection system according to any one of claims 1 to 4, wherein the index calculation unit converts the RGB values ​​in the first inspection area into color space data having at least lightness as a spatial axis, and calculates the first inspection index using the lightness value, and converts the RGB values ​​in the second inspection area into color space data having at least lightness as a spatial axis, and calculates the second inspection index using the lightness value.

7. The inspection system of claim 1 , wherein the first inspection area is offset relative to the second inspection area in the first direction.

8. 5. The inspection system according to claim 1, further comprising a determination unit that determines a product as non-defective on the condition that the absolute value of the difference between the first inspection index and the second inspection index is equal to or less than an inspection threshold value.

9. The inspection system according to any one of claims 1 to 4, wherein the index comparison unit includes a determination unit that determines an abnormality when the absolute value of the difference between the first inspection index and the second inspection index exceeds an inspection threshold.

10. The inspection system according to claim 8 , wherein the inspection threshold is set according to a distance between the first inspection area and the second inspection area in the first direction.

Images