Inspection device

Abstract

To provide an inspection device capable of holding down costs pertaining to a surface inspection of multiple works having different materials.SOLUTION: An inspection device 101 comprises: a conveyor 10 for conveying a workpiece W in a conveyance direction X1; a camera 20 for imaging the workpiece W; and illumination sections 21, 22. The conveyor 10 has a conveyance surface 11 curved upward in a side view and extends, a front side slope 13 tilted down to the front side of the conveyance direction X1 from a top 12 and a rear side slope 14 tilted down to the rear side of the conveyance direction X1 from the top 12 are provided on the conveyance surface 11, the position posture of the camera 20 relative to the conveyance 10 is fixed, inspection light L1 is applied toward one of an irradiation area 13a of the front side slope 13 and an irradiation area 14a of the rear side slope 14 from the illumination sections 21, 22 on the basis of the material of the workpiece W, and reflection light when the inspection light L1 is reflected on the surface of the workpiece W is received by the camera 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Pressed parts used in automobiles and other products are typically manufactured by cutting coil material in a cutting process and then forming the cut workpiece in a pressing process. During the cutting process, dents may occur on the workpiece surface, which can affect the appearance of the workpiece's surface quality. Therefore, to check the surface quality of the workpiece, an inspection system is used that automatically inspects the coil material using imaging devices such as cameras and lighting. In particular, when inspecting the surfaces of multiple workpieces made of different materials using the same inspection system, it is necessary to consider the differences in the reflection characteristics of the inspection light on the surface of each workpiece.

[0003] Therefore, as this type of inspection device, it is possible to use the inspection device disclosed in the following Patent Document 1. This inspection device is equipped with an acquisition means for acquiring surface information of a substrate, which is a workpiece, an angle adjustment means for adjusting the angle of incidence of inspection light from a light source with respect to an inspection area on the surface of the substrate based on the surface information of the substrate acquired by the acquisition means, and a camera adjustment means for adjusting the imaging position and imaging attitude of a camera based on the surface information of the substrate acquired by the acquisition means. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-309718 Summary of the Invention [Problem to be solved by the invention]

[0005] Using the inspection device configured as described above, the angle of incidence of the inspection light from the light source and the imaging position and orientation of the camera are adjusted according to differences in the reflection characteristics of the inspection light on the workpiece. This makes it possible to inspect the surfaces of multiple workpieces made of different materials using the same inspection device. However, using a camera adjustment device to adjust the imaging position and orientation of the camera is problematic in that it is complex and requires high equipment and maintenance costs. Therefore, a possible solution would be to install multiple cameras so that their imaging positions and orientations are different from one another. However, because the cameras themselves are expensive, this solution can also result in similar problems.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide an inspection device that can reduce the costs involved in inspecting the surfaces of a plurality of workpieces made of different materials. [Means for solving the problem]

[0007] One aspect of the present invention is An inspection device for inspecting the surface of a sheet-like workpiece, a conveyor that conveys the workpiece in a conveying direction; A camera that captures an image of the workpiece; an illumination unit capable of irradiating inspection light; Equipped with The conveyor has a conveying surface that extends and curves upward in a side view, and the conveying surface is provided with a front inclined surface that slopes downward from a top portion to a front side in the conveying direction, and a rear inclined surface that slopes downward from the top portion to a rear side in the conveying direction, The position and orientation of the camera relative to the conveyor are fixed, an inspection device configured to irradiate the inspection light from the illumination unit toward either the illumination area of ​​the front inclined surface or the illumination area of ​​the rear inclined surface based on the material of the workpiece, and receive reflected light when the inspection light is reflected on the surface of the workpiece with the camera; is located. [Effects of the Invention]

[0008] In the inspection device of the above aspect, the conveyor's conveying surface extends in a curved upward direction in a side view relative to the conveying direction, and has a front inclined surface that slopes downward from the top to the front in the conveying direction, and a rear inclined surface that slopes downward from the top to the rear in the conveying direction. The camera has a fixed position and orientation relative to the conveyor, and captures an image of the workpiece by receiving reflected light when inspection light irradiated from the illumination unit is reflected on the surface of the workpiece.

[0009] When surface inspection of multiple workpieces made of different materials is performed using the same inspection device, differences in the reflection characteristics of the inspection light on the surface of each workpiece make it difficult to properly capture each workpiece while keeping the camera's position and orientation fixed relative to the conveyor. Therefore, in this embodiment, illumination areas are set on the front and rear inclined surfaces of the conveyor's transport surface, depending on the reflection characteristics of the inspection light on the workpiece. Then, based on the material of the workpiece, the illumination unit irradiates the inspection light toward either the illumination area on the front inclined surface or the illumination area on the rear inclined surface. This makes it possible to capture multiple workpieces made of different materials using a single camera whose position and orientation are fixed relative to the conveyor. This allows for a reduction in the number of cameras. Furthermore, a structure for adjusting the camera's position and orientation is not required, eliminating the costs associated with equipment and maintenance for such a structure.

[0010] As described above, according to the above-described aspect, it is possible to provide an inspection device that can reduce costs associated with inspecting the surfaces of a plurality of workpieces made of different materials. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an overall side view of a processing facility according to a first embodiment. [Figure 2] 1 is a perspective view of the inspection device of the first embodiment as seen from diagonally above the front. [Figure 3] 3 is a cross-sectional view showing a cross section taken along line III-III in FIG. 2 together with a cross section of the workpiece. [Figure 4] FIG. 2 is a flowchart of the surface inspection method according to the first embodiment. [Figure 5] FIG. 4 is a cross-sectional view of the inspection device of FIG. 3 when inspecting the surface of a first workpiece. [Figure 6] 4 is a cross-sectional view of the inspection device of FIG. 3 when inspecting the surface of a second workpiece. [Figure 7] FIG. 4 is a cross-sectional view corresponding to FIG. 3 of the inspection device of the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Preferred embodiments of the above aspects are described below.

[0013] In the inspection device of the above-mentioned aspect, the illumination unit includes a first illumination unit capable of irradiating the inspection light toward the irradiation area of ​​the front inclined surface, and a second illumination unit capable of irradiating the inspection light toward the irradiation area of ​​the rear inclined surface, and both the first illumination unit and the second illumination unit have fixed positions and orientations relative to the conveyor, and it is preferable that the inspection light is irradiated from either the first illumination unit or the second illumination unit based on the material of the workpiece.

[0014] This inspection device uses a first lighting unit and a second lighting unit, both of which have fixed positions and orientations relative to the conveyor. The first lighting unit can emit inspection light toward an illumination area on the front inclined surface, and the second lighting unit can emit inspection light toward an illumination area on the rear inclined surface. Here, by emitting inspection light from either the first lighting unit or the second lighting unit based on the material of the workpiece, a structure for adjusting the position and orientation of each lighting unit is not required, and the costs for equipment and maintenance for such a structure are not incurred. Therefore, it is possible to further reduce the costs associated with surface inspection of multiple workpieces made of different materials.

[0015] It is preferable that the inspection device of the above-mentioned aspect is provided with a position and attitude adjustment unit that adjusts the position and attitude of the lighting unit relative to the conveyor to either a position and attitude in which the inspection light is irradiated toward the irradiation area of ​​the front inclined surface, or a position and attitude in which the inspection light is irradiated toward the irradiation area of ​​the rear inclined surface, based on the material of the workpiece.

[0016] According to this inspection device, by adjusting the position and orientation of the lighting unit relative to the conveyor based on the material of the workpiece, it is possible to perform surface inspection of multiple workpieces made of different materials using a single lighting unit.

[0017] In the inspection device of the above-described aspect, it is preferable that the irradiation area of ​​the front inclined surface and the irradiation area of ​​the rear inclined surface are set so that the reflected light of the inspection light heading toward the irradiation area travels parallel to each other.

[0018] According to this inspection device, by providing irradiation areas on the front and rear inclined surfaces so that the reflected light travels parallel to each other, the position and orientation of the camera can be unified regardless of the material of the workpiece.

[0019] In the inspection device of the above aspect, it is preferable that the conveyor is configured so that the inclination angle of the front inclined surface and the rear inclined surface relative to a horizontal reference plane extending horizontally along the conveying direction is the same.

[0020] According to this inspection device, by matching the inclination angles of the front inclined surface and the rear inclined surface with respect to the horizontal reference plane, the inclined shape of the conveyor's transport surface can be made symmetrical between the front and rear.

[0021] The inspection device of the above aspect preferably includes a guide mechanism that guides the workpiece so that it follows the shape of the transport surface of the conveyor.

[0022] According to this inspection device, even if the workpiece is warped, the guide mechanism guides the workpiece so that it follows the shape of the conveyor's transport surface, thereby suppressing the warping. This prevents the accuracy of the surface inspection results from decreasing due to the warping of the workpiece (for example, variations in the detection of defects).

[0023] In the inspection device of the above-mentioned aspect, it is preferable that the conveying surface of the conveyor has a plurality of through holes, and the guide mechanism unit includes a support unit that supports the back surface of the conveyor and an intake case having an intake space that communicates with the plurality of through holes of the conveyor, and a suction machine that is connected to the intake case so as to be able to suck in air from the intake space.

[0024] According to this inspection device, the suction force of the suction machine is used to suck in the air in the intake space of the intake case, so that the air on the conveyor's conveying surface side flows into the intake space of the intake case through the multiple through holes, and the workpieces are sucked onto the conveying surface so as to follow the curved shape of the conveyor's conveying surface. A structure that attracts the workpieces to the conveying surface by the suction force of the suction machine is advantageous in that it is highly effective in suppressing warping during surface inspection of the workpieces.

[0025] In the inspection device of the above aspect, the camera is preferably an area camera that images the workpiece in a plane.

[0026] This inspection device uses an area camera, which allows it to capture images of the workpiece with a wider field of view than a line camera, which has a single field of view. This has the advantage that it is not necessary to precisely align the positional relationship with the lighting unit, and errors in this positional relationship can be tolerated.

[0027] Hereinafter, specific embodiments of the inspection device of the above aspect will be described with reference to the drawings.

[0028] In this specification and drawings, unless otherwise specified, the front-to-back direction along the workpiece transport direction X1 is indicated by arrow X, the left-to-right direction perpendicular to the front-to-back direction is indicated by arrow Y, and the up-to-down direction perpendicular to the front-to-back direction is indicated by arrow Z.

[0029] (Embodiment 1) As shown in Fig. 1, the processing equipment 1 according to the first embodiment is equipment for processing a coil material C made of a metal material. The processing equipment 1 includes, as its main components, an uncoiler 2, a leveler 3, a down looper 4, a feeder 5, a press 6, and a take-out device 8.

[0030] The uncoiler 2 is provided with a coil inner diameter holder and a coil outer diameter holder so that the coil material C can be freely unwound. The leveler 3 has the function of flattening the strip-shaped coil material C unwound from the coil material C. The coil material C flattened by the leveler 3 is introduced into the press machine 6 via the down looper 4 and the feeder 5.

[0031] In the press machine 6, in a press processing area 6a defined by a lower die D1 and an upper die D2, processing such as cutting the coil material C to a desired length and drilling holes in the coil material C is carried out. The rear end of the coil material C is cut in the press processing area 6a of the press machine 6, thereby generating a sheet-like workpiece W, which is the rear end material of the coil. The workpiece W is a flexible metal plate.

[0032] The workpiece W includes a predetermined length of product material and a short, missing piece of material. The product material is used for the product, and the missing piece of material is discarded. As an example, the following describes the case where the workpiece W that will become the product material is removed.

[0033] The take-out device 8 is configured to take the workpiece W generated by the press machine 6 out of the press processing area 6a and transport it in the transport direction X1 on a conveyor 10. This take-out device 8 is provided with an inspection device 101 for inspecting the surface of the sheet-like workpiece W.

[0034] 1. Structure of the inspection device 101 As shown in FIG. 1, the inspection device 101 of the first embodiment includes a conveyor 10, a camera 20, a first illumination unit 21, and a second illumination unit 22.

[0035] 1-1. Structure of conveyor 10 The conveyor 10 is a belt conveyor formed in a loop by a wide belt whose width direction is the second direction Y. As shown in Figures 2 and 3, the conveyor 10 has a conveying surface 11 on which the workpieces W are placed and conveyed. The conveying surface 11 extends and curves upward in a side view in the left-right direction Y that intersects the conveying direction X1.

[0036] The conveying surface 11 of the conveyor 10 is provided with a front inclined surface 13 that slopes downward from the apex 12 to the front in the conveying direction X1, and a rear inclined surface 14 that slopes downward from the apex 12 to the rear in the conveying direction X1. An illumination area 13a by the first illumination unit 21 is set in advance on the front inclined surface 13. An illumination area 14a by the second illumination unit 22 is set in advance on the rear inclined surface 14. The illumination areas 13a, 14a are areas that extend in a strip shape in the left-right direction Y. In addition, a plurality of through holes 15 are provided on the conveying surface 11 of the conveyor 10. As shown in FIG. 3, in this embodiment, the conveyor 10 is configured so that the inclination angle θ4 with respect to a horizontal reference plane H that extends horizontally along the conveying direction X1 is the same for the front inclined surface 13 and the rear inclined surface 14. According to this configuration, by matching the inclination angle θ4 of the front inclined surface 13 and the rear inclined surface 14 with respect to the horizontal reference plane H, the inclined shape of the transfer surface 11 of the conveyor 10 can be made symmetrical in the front and rear directions.

[0037] As shown in Figures 2 and 3, the conveyor 10 is provided with work guides 16. The work guides 16 are provided on both sides of the conveyor 10 in the left-right direction Y. The work guides 16 are for transporting the work W along the transport surface 11, and extend in the front-rear direction X along the transport surface 11. The work guides 16 are configured to form a gap between the work guides 16 and the transport surface 11 of the conveyor 10, taking into account the amount of warping of the work W. When the work W is transported on the transport surface 11, it comes into contact with the work guides 16 and is pressed against the transport surface 11. This makes it possible to guide the work W in a way that suppresses warping of the work W.

[0038] As shown in Figures 2 and 3, the conveyor 10 is provided with a workpiece pressure roller 17. The workpiece pressure roller 17 is used to transport the workpiece W along the transport surface 11. The workpiece pressure roller 17 is a cylindrical member with a circular cross-sectional shape and is configured to be rotatable about a central shaft 17a extending in the left-right direction Y. The workpiece pressure roller 17 is disposed above the transport surface 11 of the conveyor 10 so as to form a gap between the workpiece pressure roller 17 and the transport surface 11 of the conveyor 10 that takes into account the amount of warping of the workpiece W. As the workpiece W is transported on the transport surface 11, it comes into contact with the workpiece pressure roller 17 and is pressed against the transport surface 11. At this time, the workpiece pressure roller 17 rotates about the central shaft 17a due to contact with the top surface of the workpiece W. This makes it possible to guide the workpiece W while suppressing warping of the workpiece W.

[0039] As shown in Figures 2 and 3, an intake case 18 is provided below the conveyor 10 in the up-down direction Z. As shown in Figure 3, the intake case 18 has a support portion 18a, an intake space 18c, and an exhaust port 18d. The support portion 18a is a portion that supports the back surface 10a of the conveyor 10. The support portion 18a extends and curves upward in a side view in the left-right direction Y in order to form the curved shape of the conveying surface 11. This support portion 18a is provided with a plurality of through holes 18b that communicate with the plurality of through holes 15 in the conveying surface 11 of the conveyor 10. The intake space 18c is a space that communicates with the plurality of through holes 18b. Therefore, this intake space 18c communicates with the plurality of through holes 15 in the conveying surface 11. A suction device 19 is connected to the intake case 18.

[0040] The suction device 19 is configured to be able to suck air from the intake space 18c of the intake case 18 through the exhaust port 18d. The suction device 19 is controlled by the control device 30 (see FIG. 3) so as to operate at least when the workpiece W is being transported. By sucking air from the intake space 18c of the intake case 18 using the suction force of the suction device 19, air on the conveying surface 11 side of the conveyor 10 flows into the intake space 18c of the intake case 18 through the multiple through holes 15 and the multiple through holes 18b. At this time, the workpiece W is sucked onto the conveying surface 11 so as to follow the curved shape of the conveying surface 11 of the conveyor 10 in accordance with its flexibility. This allows the workpiece W to be guided so as to suppress warping of the workpiece W.

[0041] As described above, the work guide 16, work holding roller 17, and suction device 19 constitute a guide mechanism that guides the work W so that it follows the shape of the conveying surface 11 of the conveyor 10. If necessary, at least one of the work guide 16, work holding roller 17, and suction device 19 can be used. This guide mechanism is also a component of the inspection device 101.

[0042] By using the guide mechanism to guide the workpiece W so that it follows the shape of the conveying surface 11 of the conveyor 10, even if the workpiece W is warped, this warping can be suppressed. This makes it possible to prevent the accuracy of the surface inspection results from decreasing due to the warping of the workpiece W (for example, variations in the detection of defects).

[0043] 1-2. Structure of camera 20 As shown in Figures 2 and 3, the camera 20 is used to photograph the workpiece W being transported on the transport surface 11 by the conveyor 10. The camera 20 is controlled by a control device 30 (see Figure 3). The camera 20 is an area camera that captures (also referred to as "photographing") the workpiece W on a surface. The position and orientation of the camera 20 relative to the conveyor 10 are fixed. In this embodiment, the position and orientation of the camera 20 is set to a position and orientation P that forms a field of view that extends from above the transport surface 11 of the conveyor 10 diagonally downward and rearward.

[0044] 1-3. Structure of lighting units 21 and 22 2 and 3, both the first lighting unit 21 and the second lighting unit 22 are configured to be able to emit inspection light L1 for surface inspection of the surface of the workpiece W. Similar to the camera 20, the lighting units 21 and 22 have fixed positions and orientations relative to the conveyor 10.

[0045] The position and posture of the first illumination unit 21 is a downward position and posture Q1 from above the transport surface 11 of the conveyor 10 toward the illumination area 13a of the front inclined surface 13. Therefore, the first illumination unit 21 is provided so as to be able to irradiate the inspection light L1 toward the illumination area 13a of the front inclined surface 13. Furthermore, the position and posture of the second illumination unit 22 is a forward position and posture Q2 from above the transport surface 11 of the conveyor 10 toward the illumination area 14a of the rear inclined surface 14. Therefore, the second illumination unit 22 is provided so as to be able to irradiate the inspection light L1 toward the illumination area 14a of the rear inclined surface 14.

[0046] 3, the illumination units 21 and 22 are controlled by a control device 30. The control device 30 controls the first illumination unit 21 and the second illumination unit 22 so that the inspection light L1 is emitted from either the first illumination unit 21 or the second illumination unit 22 based on the material of the workpiece W. When the inspection light L1 is emitted from the first illumination unit 21 toward the illumination area 13a of the front inclined surface 13, the camera 20 receives the reflected light of the inspection light L1 reflected by the surface of the workpiece W. Similarly, when the inspection light L1 is emitted from the second illumination unit 22 toward the illumination area 14a of the rear inclined surface 14, the camera 20 receives the reflected light of the inspection light L1 reflected by the surface of the workpiece W.

[0047] The control device 30 has a function of controlling the equipment related to the surface inspection of the workpiece W, as well as a function of storing the results of the surface inspection and a function of outputting the results of the surface inspection to a display unit (not shown). The control device 30 is a computer device having a known CPU (Central Processing Unit), ROM, RAM, an interface for inputting and outputting data to and from external devices, etc. For example, a desktop or notebook personal computer (PC), a tablet terminal, a mobile terminal, etc. can be used as the computer device.

[0048] 2. Surface inspection method for workpiece W Next, a method for inspecting the surface of a workpiece W will be described with reference to Figs. 4 to 6. In this method, the processes from step S101 to step S105 in the flowchart shown in Fig. 4 are executed sequentially. Each process is executed by the control device 30. If necessary, another step may be added to these steps, or at least one step may be divided into multiple steps.

[0049] Step S101 in Fig. 4 is a step for selecting the lighting units 21, 22 corresponding to the material of the workpiece W to be inspected (the workpiece W produced by the press machine 6 in Fig. 1). Information relating to the link between the material of the workpiece W and the lighting units 21, 22 is stored in advance in a memory unit (not shown) of the control device 30.

[0050] In this embodiment, a case will be described as an example in which a first workpiece Wa (see FIG. 5) made primarily of an aluminum-based material and a second workpiece Wb (see FIG. 6) made primarily of an iron-based material are surface inspected as workpieces W to be surface inspected. When surface inspecting the first workpiece Wa, the first illumination unit 21 is selected, and when surface inspecting the second workpiece Wb, the second illumination unit 22 is selected. The position and orientation Q1 of the first illumination unit 21 is preset as an optimal position and orientation based on the material of the first workpiece Wa. Similarly, the position and orientation Q2 of the second illumination unit 22 is preset as a position and orientation based on the material of the second workpiece Wb. Positions and orientations Q1 and Q2 that are suitable for the material of the workpiece W to be surface inspected are appropriately selected. In step S101 of this embodiment, it is assumed that the first illumination unit 21 corresponding to the first workpiece Wa is selected.

[0051] Step S102 in FIG. 4 is a step of capturing an image of the first workpiece Wa being transported by the conveyor 10. As shown in FIG. 5, in step S102, inspection light L1 is emitted from the first illumination unit 21, which is in position and orientation Q1, toward the illumination area 13a (see FIGS. 2 and 3) of the front inclined surface 13. Then, when this inspection light L1 is reflected by the surface of the first workpiece Wa, reflected light L2 is received by the camera 20. According to step S102, a captured image of the first workpiece Wa is obtained. The image I of the camera 20 includes a strip-shaped imaging area Ia that represents a portion of the first workpiece Wa (see FIG. 5).

[0052] As shown in FIG. 5, when the first workpiece Wa is imaged by the camera 20, the inspection light L1 is irradiated onto the irradiation area A on the surface of the first workpiece Wa at an incident angle θ1 with respect to the perpendicular line M1 of the front inclined surface 13. The inspection light L1 is reflected at the irradiation area A at a reflection angle θ1 with respect to the perpendicular line M1 to form reflected light L2. The reflected light L2 then travels toward the camera 20 at an inclination angle θ3 with respect to the vertical line V1. The incident angle θ1 and the reflection angle θ1 are optimal angles that are effective for properly imaging the first workpiece Wa with the camera 20 irradiated with the inspection light L1 when the first workpiece Wa is placed on a flat surface. For this reason, the incident angle θ1 and the reflection angle θ1 are set in advance before surface inspection of the first workpiece Wa.

[0053] It is preferable that the imaging of the first workpiece Wa be performed while the suction device 19 is operating. In particular, the structure in which the first workpiece Wa is attracted to the conveying surface 11 by the suction force of the suction device 19 is advantageous in that it is highly effective in suppressing warping of the first workpiece Wa during surface inspection. Furthermore, by using the suction device 19, the cooperation of the suction device 19 with the work guide 16 and the workpiece pressing roller 17 further enhances the effect of suppressing warping of the first workpiece Wa.

[0054] Step S103 in Fig. 4 is a step for performing image processing on the captured image of the first workpiece Wa obtained in step S102. In step S103, image processing is performed to stitch together multiple captured images Ia obtained when the first workpiece Wa is continuously captured by the camera 20. Also, in step S103, processing is performed to extract information regarding defects on the surface of the first workpiece Wa from the image information obtained by the image processing.

[0055] 4, it is determined whether or not to detect the next workpiece W. If the next workpiece W is to be detected ("Yes" in step S104), the process proceeds to step S105, and if not ("No" in step S104), the process ends.

[0056] 4, it is determined whether the next workpiece W is a workpiece W made of a different material. If the next workpiece W is a workpiece W made of a different material (if "Yes" in step S105), the process returns to step S101, and if not (if "No" in step S105), the process returns to step S102.

[0057] In this embodiment, when it is determined in step S105 that the next workpiece W is the first workpiece Wa, the workpieces W to be inspected are made of the same material, and so the same processing is repeated from step S102. In contrast, when it is determined in step S105 that the next workpiece W is the second workpiece Wb, the workpiece W to be inspected has changed from the first workpiece Wa to the second workpiece Wb, and the processing is repeated from step S101 for the second workpiece Wb.

[0058] In step S101, the second illumination unit 22 corresponding to the second workpiece Wb is selected instead of the first illumination unit 21. In step S102, an image of the second workpiece Wb is obtained. At this time, the image I of the camera 20 includes a strip-shaped image portion Ib representing a portion of the second workpiece Wb (see FIG. 6). Then, in step S103, image processing is performed to stitch together multiple image portions Ib obtained when the second workpiece Wb is continuously imaged by the camera 20. Also in step S103, processing is performed to extract information regarding defects on the surface of the second workpiece Wb from the image information obtained by the image processing.

[0059] As shown in FIG. 6, when the second workpiece Wb is imaged by the camera 20, the inspection light L1 is irradiated onto the irradiation area A on the surface of the second workpiece Wb at an incident angle θ2 with respect to the perpendicular line M2 of the rear inclined surface 14. The inspection light L1 is reflected at the irradiation area A at a reflection angle θ2 with respect to the perpendicular line M2 to form reflected light L2. The reflected light L2 then travels toward the camera 20 at an inclination angle θ3 with respect to the vertical line V1. The incident angle θ2 and the reflection angle θ2 are optimal angles that are effective for properly imaging the second workpiece Wb with the camera 20 irradiated with the inspection light L1 when the second workpiece Wb is placed on a flat surface. For this reason, the incident angle θ2 and the reflection angle θ2 are set in advance before surface inspection of the second workpiece Wb.

[0060] As described above, the reflected light L2 travels parallel to the camera 20 at an inclination angle θ3 with respect to the vertical line V1, both when imaging the first workpiece Wa (see FIG. 5) and when imaging the second workpiece Wb (see FIG. 6). For this reason, the illumination area 13a of the front inclined surface 13 and the illumination area 14a of the rear inclined surface 14 are set so that the reflected light L2 of the inspection light L1 heading toward the illumination area travels parallel to each other. This allows the position and orientation of the camera 20 to be consistent regardless of the material of the workpiece W.

[0061] In the surface inspection method of FIG. 4, the image processing in step S103 may be performed collectively after all of the workpieces W have been imaged, instead of being performed each time an image of each workpiece W is imaged.

[0062] 3. Effects According to the above-described first embodiment, the following effects can be obtained.

[0063] When surface inspection of multiple workpieces Wa, Wb made of different materials is performed using the same inspection device, it is difficult to properly capture images of each workpiece W while keeping the position and orientation of the camera 20 fixed relative to the conveyor 10 due to differences in the reflection characteristics of the inspection light on the surface of each workpiece W. Therefore, in the first embodiment, illumination areas 13a, 14a corresponding to the reflection characteristics of the inspection light L1 on the workpiece W are set on the front inclined surface 13 and the rear inclined surface 14 of the conveyor 10. Then, based on the material of the workpiece W, the inspection light L1 is irradiated from the illumination units 21, 22 toward either the illumination area 13a on the front inclined surface 13 or the illumination area 14a on the rear inclined surface 14. This makes it possible to capture images of multiple workpieces Wa, Wb made of different materials using a single camera 20, even when the camera 20 has a fixed position and orientation P relative to the conveyor 10. This reduces the number of cameras 20. Furthermore, a structure for adjusting the position and orientation P of the camera 20 is not required, eliminating the costs associated with equipment and maintenance for such a structure.

[0064] As described above, according to the first embodiment, it is possible to provide the inspection device 101 that can reduce the cost involved in inspecting the surfaces of a plurality of workpieces Wa and Wb made of different materials.

[0065] According to the inspection device 101, by using an area camera as the camera 20, it is possible to image the workpiece W with a wider field of view than a line camera with a single field of view. This has the advantage that it is not necessary to strictly align the positional relationship with the illumination units 21 and 22, and even if there is an error in the positional relationship, it is acceptable.

[0066] According to the inspection device 101, by irradiating the inspection light L1 from either the first illumination unit 21 or the second illumination unit 22 based on the material of the workpiece W, a structure for adjusting the position and orientation of each illumination unit is not required, and no costs are incurred for equipment and maintenance for such a structure. Therefore, it is possible to further reduce the costs associated with surface inspection of multiple workpieces Wa, Wb made of different materials.

[0067] Hereinafter, other embodiments related to the above-described embodiment 1 will be described with reference to the drawings. In the other embodiments, the same elements as those in embodiment 1 are denoted by the same reference numerals, and the description of the same elements will be omitted.

[0068] (Embodiment 2) 7, the inspection device 102 of the second embodiment differs from the inspection device 101 of the first embodiment in that it uses only the illumination unit 21 to irradiate the inspection light L1. The inspection device 102 includes a position and orientation adjustment unit 23.

[0069] The position and attitude adjustment unit 23 has a function of adjusting the position and attitude of the illumination unit 21 relative to the conveyor 10 to either position and attitude Q1 or position and attitude Q2 based on the material of the workpiece W. In this embodiment, when inspecting the surface of the workpiece Wa, the illumination unit 21 is adjusted to position and attitude Q1 to irradiate the inspection light L1 toward the irradiation area 13a of the front inclined surface 13. On the other hand, when inspecting the surface of the workpiece Wb, the illumination unit 21 is adjusted to position and attitude Q2 to irradiate the inspection light L1 toward the irradiation area 14a of the rear inclined surface 14.

[0070] The other configurations and surface inspection methods are the same as those in the first embodiment.

[0071] According to embodiment 2, by adjusting the position and posture of the illumination unit 21 relative to the conveyor 10 based on the material of the workpiece W, it becomes possible to perform surface inspection of multiple workpieces Wa, Wb made of different materials using a single illumination unit 21.

[0072] In addition, the same effects as those of the first embodiment are achieved.

[0073] The present invention is not limited to the exemplary embodiments described above, and various applications and modifications are possible without departing from the scope of the present invention. For example, the following embodiments can be implemented by applying the above embodiments.

[0074] In the above embodiment, the surface inspection of the workpiece W, which is a metal plate, is illustrated, but the material of the workpiece W to be inspected is not limited to a metal material. For example, the surface inspection of the workpiece W, which is a resin film made of a resin material, can also be performed.

[0075] In the above-described embodiment, an example was given in which the inclination angle θ4 relative to the horizontal reference plane H is the same for the front inclined surface 13 and the rear inclined surface 14, but instead, the inclination angle θ4 may be different for the front inclined surface 13 and the rear inclined surface 14.

[0076] In the above embodiment, an example was given in which the inclination angle θ3 of the reflected light L2 is the same when using the first lighting unit 21 and when using the second lighting unit 22, but instead, the inclination angle θ3 may be different between the first lighting unit 21 and the second lighting unit 22.

[0077] In the above embodiment, an example was given in which an area camera was used as the camera 20, but a line camera may be used instead. [Explanation of symbols]

[0078] 10... conveyor, 10a... back surface, 11... transport surface, 12... top, 13... front inclined surface, 13a... irradiation area, 14... rear inclined surface, 14a... irradiation area, 15... through hole (guide mechanism), 16... work guide (guide mechanism), 17... work holding roller (guide mechanism), 18... intake case (guide mechanism), 18a... support part, 18c... intake space, 19... suction machine (guide mechanism), 20... camera, 21... first lighting unit (lighting unit), 22... second lighting unit (lighting unit), 23... position and attitude adjustment unit, 101, 102... inspection device, H... horizontal reference plane, L1... inspection light, L2... reflected light, Q1, Q2... position and attitude, W, Wa, Wb... work, X1... transport direction, θ4: Inclination angle relative to the horizontal reference plane

Claims

1. An inspection device for inspecting the surface of a sheet-like workpiece, a conveyor that conveys the workpiece in a conveying direction; A camera that captures an image of the workpiece; an illumination unit capable of irradiating inspection light; Equipped with The conveyor has a conveying surface that extends and curves upward in a side view, and the conveying surface is provided with a front inclined surface that slopes downward from a top portion to a front side in the conveying direction, and a rear inclined surface that slopes downward from the top portion to a rear side in the conveying direction, The position and orientation of the camera relative to the conveyor are fixed, An inspection device configured to irradiate the inspection light from the lighting unit toward either the illumination area of ​​the front inclined surface or the illumination area of ​​the rear inclined surface based on the material of the workpiece, and to receive the reflected light when the inspection light is reflected by the surface of the workpiece with the camera.

2. 2. The inspection device of claim 1, wherein the illumination unit includes a first illumination unit capable of irradiating the inspection light toward the irradiation area of ​​the front inclined surface and a second illumination unit capable of irradiating the inspection light toward the irradiation area of ​​the rear inclined surface, and the first illumination unit and the second illumination unit both have fixed positions and orientations relative to the conveyor, and the inspection light is irradiated from either the first illumination unit or the second illumination unit based on the material of the workpiece.

3. 2. The inspection device according to claim 1, further comprising a position and attitude adjustment unit that adjusts the position and attitude of the illumination unit relative to the conveyor to either a position and attitude in which the inspection light is irradiated toward the irradiation area on the front inclined surface, or a position and attitude in which the inspection light is irradiated toward the irradiation area on the rear inclined surface, based on the material of the workpiece.

4. The inspection device according to any one of claims 1 to 3, wherein the irradiation area of ​​the front inclined surface and the irradiation area of ​​the rear inclined surface are set so that the reflected light of the inspection light heading toward the irradiation area travels parallel to each other.

5. The inspection device according to any one of claims 1 to 3, wherein the conveyor is configured so that the inclination angle of the front inclined surface and the rear inclined surface relative to a horizontal reference plane extending horizontally along the conveying direction is the same.

6. 4. The inspection device according to claim 1, further comprising a guide mechanism that guides the workpiece so that it follows the shape of the transport surface of the conveyor.

7. A plurality of through holes are provided in the conveying surface of the conveyor, 7. The inspection device according to claim 6, wherein the guide mechanism comprises: a support portion that supports the rear surface of the conveyor; an intake case having an intake space that communicates with the plurality of through holes of the conveyor; and a suction machine connected to the intake case so as to be able to suck air from the intake space.

8. 4. The inspection device according to claim 1, wherein the camera is an area camera that captures an image of the workpiece in a plane.

Images