JP7708632B2 - Visual inspection device and visual inspection method - Google Patents

Description

One aspect of the present invention relates to an apparatus and method for visual inspection of parts.

Patent Document 1 describes an appearance inspection device that captures the appearance of a component to inspect the electrode shape, surface defects, scratches, dirt, foreign matter, etc. of the component. The appearance inspection device in Patent Document 1 includes an imaging means with an imaging surface facing a position facing the bottom surface of the component, and mirrors provided corresponding to the four side surfaces of the component, and the mirror reflects images of the four side surfaces of the component toward the imaging surface of the imaging means, and the imaging means captures images of the four side surfaces in addition to the bottom surface image.

With this configuration, multiple faces of a component can be imaged with a single imaging means, which reduces costs compared to a configuration in which an imaging means is provided for each face of a component, and simplifies the imaging process by eliminating the need to switch between imaging means.

JP 2009-276338 A

In the above-mentioned appearance inspection device, the part is transported to the imaging area and the part is stopped in the imaging area to perform imaging processing. Here, from the viewpoint of imaging at high resolution, it is preferable that the above-mentioned mirror is close to the part. On the other hand, from the viewpoint of properly transporting the part, it is necessary to separate the mirror from the part to an extent that allows the part to be transported. Thus, in the past, it was difficult to achieve both ease of transporting the part and imaging the part at high resolution.

One aspect of the present invention has been made in consideration of the above-mentioned circumstances, and relates to an appearance inspection device and an appearance inspection method that ensures the transportability of a part and enables the part to be imaged at high resolution in a configuration in which multiple surfaces of the part are imaged by a single imaging means.

The visual inspection device according to one aspect of the present invention is a visual inspection device that inspects the surface condition of a part, and includes a transport unit configured to transport a placed part along a transport path to an imaging area, an imaging unit that faces the part transported to the imaging area in a first direction and captures the part, a plurality of mirrors that are arranged to surround the part transported to the imaging area when viewed in the first direction and reflect an image of the part toward the imaging surface of the imaging unit, a movement mechanism configured to move the plurality of mirrors, and a control device, and the control device is configured to execute a first control that controls the transport unit so that the part is transported to the imaging area and stops at the imaging area, a second control that controls the movement mechanism so that the plurality of mirrors move toward the imaging area after the first control, a third control that controls the imaging unit to capture an image of the part after the second control, and a fourth control that controls the movement mechanism so that the plurality of mirrors move in a direction away from the transport path including the imaging area after the third control.

In the appearance inspection device according to one aspect of the present invention, multiple mirrors that reflect the image of the part toward the imaging surface of the imaging unit are arranged to surround the part transported to the imaging area, so that multiple sides of the part can be imaged by one imaging unit. Compared to a configuration in which an imaging means is provided for each side of the part, for example, costs are reduced and the imaging process is simplified by eliminating the need to switch between imaging means. In the appearance inspection device according to one aspect of the present invention, when the part is stopped in the imaging area, the movement mechanism is controlled so that the multiple mirrors move toward the imaging area, and then the imaging unit images the part. In this way, the multiple mirrors are moved toward the imaging area and the imaging of the part is performed in that state, so that the multiple mirrors are close to the part when the part is imaged, and the imaging of the part is performed with the frame frame being small when the part is imaged, so that the imaging of the part can be achieved with high resolution (high pixel). Furthermore, in the visual inspection device according to one aspect of the present invention, after imaging, the multiple mirrors are moved in a direction away from the transport path including the imaging area, so that the multiple mirrors are not placed on the transport path except when imaging (before and after imaging), and the multiple mirrors do not interfere with the transport of parts. As described above, in the visual inspection device according to one aspect of the present invention, the control device causes the movement mechanism to move the multiple mirrors, ensuring the transportability of parts and allowing the parts to be imaged at high resolution.

The visual inspection device further includes a support section that supports the component to be transported to the imaging area, and at least the underside of the component is formed in an arch shape, and the surface of the support section that supports the component may be formed in a V shape with a central portion concave downward to correspond to the shape of the arch-shaped component. In this way, the surface of the support section that supports the component is formed in a V shape that conforms to the shape of the component, which effectively prevents the component from being placed on the support section in a misaligned state in the θ direction relative to the axis of the support section when the support section receives the component.

The above-mentioned appearance inspection device further includes a holding jig that holds down the part transported to the positioning area upstream of the imaging area on the transport path from above and positions the part in the front-rear direction, and the control device may be configured to further execute a fifth control that controls the transport unit so that the part is transported to the positioning area and stops in the positioning area before the first control, and a sixth control that controls the holding jig so that the part is held down after the fifth control and before the first control. If the position (orientation) of the part transported to the imaging area is different from the expected position (orientation), it may not be possible to inspect the part after imaging with high accuracy. For example, it is possible to correct the position of the part by using image software, but even if such position correction is performed, the inspection accuracy of the part may not be sufficiently guaranteed. In this regard, in the positioning area upstream of the imaging area, the part is held down by the holding jig and the part is positioned in the front-rear direction (i.e., the position correction of the part is actually performed instead of software correction), thereby improving the inspection accuracy based on the imaging result in the imaging area. Specifically, the part is pressed down from above by the holding jig, correcting the rolling misalignment of the part (misalignment in the direction in which the arch-shaped part rotates), and the holding jig positions the part in the front-to-back direction, correcting the front-to-back misalignment of the part, improving inspection accuracy.

The part may be substantially rectangular when viewed in the first direction, and the multiple mirrors may include four mirrors arranged at each of the four corners of the part when viewed in the first direction to reflect images of the corners. By arranging each mirror at a corner in this manner, each mirror can capture an image of two sides adjacent to the corner (two sides when viewed in the first direction), allowing each face of the part to be properly imaged.

The control device is configured to further execute a seventh control for determining whether the part is good or bad based on the imaging results of the imaging unit in the third control, and in the seventh control, a correction process may be performed to correct the dimensions by multiplying the dimensions by a reduction rate according to the distance from the corner of the part, and then the quality of the part may be determined. By performing such a correction process, the actual dimensions can be estimated with high accuracy taking into account the distance from the corner, and the accuracy of the part quality determination can be improved.

The above-mentioned appearance inspection device may further include a first light arranged above the part transported to the imaging area and irradiating light onto the part, and a second light arranged below the part transported to the imaging area and irradiating light onto the part. By providing a second light irradiating light from below the part in addition to the first light irradiating light from above the part, light can be appropriately irradiated onto the underside (bottom surface) of the part, which is difficult to irradiate with light when only the first light is used, and imaging results that are more likely to improve inspection accuracy can be obtained.

The visual inspection method according to one aspect of the present invention is a visual inspection method for inspecting the surface condition of a part, and includes a first step of transporting the part to an imaging area by a transport unit and stopping the part in the imaging area, a second step of moving a plurality of mirrors arranged to surround the part transported to the imaging area toward the imaging area by a movement mechanism after the first step, a third step of capturing an image of the part by the imaging unit after the second step, and a fourth step of moving the plurality of mirrors away from the imaging area by the movement mechanism after the third step.

According to one aspect of the present invention, in a configuration in which multiple surfaces of a part are imaged using a single imaging device, it is possible to ensure the transportability of the part and to image the part with high resolution.

FIG. 1 is a schematic diagram showing an overall configuration of a visual inspection apparatus. FIG. 2 is a perspective view showing a schematic view of a workpiece to be inspected; FIG. 2 is a diagram illustrating the state in each region. 5A to 5C are diagrams illustrating the operation of a mirror opening and closing mechanism. FIG. 4 is a diagram illustrating a first illumination and a second illumination. FIG. 11 is a diagram showing an example of an imaging result. FIG. 11 is a diagram illustrating division correction. FIG. 2 is a hardware configuration diagram of a controller. 13 is a flowchart showing a visual inspection process.

The following describes the embodiments in detail with reference to the drawings. In the description, the same elements or elements having the same functions are given the same reference numerals, and duplicate descriptions are omitted.

Figure 1 is a schematic diagram showing the overall configuration of an appearance inspection device 1. The appearance inspection device 1 shown in Figure 1 is a device that inspects the surface condition of a workpiece, which is a component. The appearance inspection device 1 judges the quality of the workpiece by inspecting the surface condition of the workpiece. Inspecting the surface condition of a workpiece means inspecting whether or not there is a defect corresponding to a predetermined defect item on the surface of the workpiece. The predetermined defect items are, for example, chips, cracks, dirt (stains), sand, black spots, polishing defects, rattles, cut defects, etc. A chip is a defect in which a part of the workpiece W is chipped off and a concave part is generated. A crack is a defect in which a streak-like concave part is generated. A stain (stain) is a defect in which dirt remains due to insufficient cleaning, for example. A sand is a defect in which a round concave part is generated. Black spots are a defect in deformation and shrinkage in the remaining polished part (part that has not been polished sufficiently). A polishing defect is a defect in a part that has been partially cut too much. A rattle is a defect caused by variation in the height of the foot part. A cut defect is a defect in which the chamfer balance is deteriorated. A specific inspection method will be described later. As shown in FIG. 1, the appearance inspection device 1 has an inspection unit 10 and a controller 90 (control device).

As shown in FIG. 1, the inspection unit 10 includes a conveyor 11 (transport section), a camera 12 (imaging section), multiple mirrors 13, mirror opening/closing mechanisms 14, 15, a support section 16, a first light 17, second lights 18, 19, and a positioning jig 20 (see FIG. 3(b) and FIG. 3(d)). Each component included in the inspection unit 10 is controlled by a controller 90. The appearance inspection device 1 inspects the surface condition of a workpiece W, which is a component, according to the control of the controller 90. The workpiece W is, for example, a magnetic component.

2 is a perspective view showing a workpiece W to be inspected. As shown in FIG. 2, the workpiece W is formed in an arch shape. As shown in FIG. 2, the workpiece W has an outer R surface Wo formed in an arch shape, an inner R surface Wi which is the reverse side of the outer R surface Wo and formed in an arch shape, an A end surface Wa which is both end surfaces in the length direction of the workpiece W, a B end surface Wb which is both end surfaces in the width direction of the workpiece W, and a lifting surface Wy and a leg portion Wx which connect the lower end of the A end surface Wa and the end of the inner R surface Wi. The outer R surface Wo is a surface supported by a support portion 16 described later, and is formed in an arch shape along the X direction (see FIG. 3(b) and the like). As shown in FIG. 1, the workpiece W is approximately rectangular when viewed in the vertical direction (first direction).

Returning to FIG. 1, the conveyor 11 is a conveyor that conveys the workpiece W that the operator puts into the inspection unit 10. That is, the conveyor 11 is a conveying section configured to be able to convey the placed workpiece W along the conveying path to the imaging area A2. The conveyor 11 may be, for example, a timing belt conveyor having a timing belt 11a and a timing pulley 11b (see FIG. 3B). In this case, the power source of the conveyor 11 may be, for example, a servo motor (not shown). The conveyor 11 operates as follows by receiving a control signal from the controller 90. That is, the conveyor 11 conveys the workpiece W that is put in by the operator and located in the input area A0 to the positioning area A1 and temporarily stops. In the positioning area A1, a positioning process of the workpiece W is performed (details will be described later). Next, the conveyor 11 conveys the workpiece W located in the positioning area A1 to the imaging area A2 and temporarily stops. In the imaging area A2, an imaging process of the workpiece W is performed (details will be described later). Next, the conveyor 11 transports the workpiece W located in the imaging area A2 to the discharge area A3. The workpiece W is discharged from the discharge area A3 to the outside of the inspection unit 10 and supplied to a subsequent process.

The support section 16 is configured to support the workpiece W being transported to the imaging area A2. The support section 16 receives the workpiece W inserted by the worker in the input area A0, and supports the workpiece W being transported by the conveyor 11. Note that Figures 1, 3(a), and 3(b) show the support section 16 in the input area A0 before supporting the workpiece W. With the workpiece W supported by the support section 16, the support section 16 is transported to the conveyor 11, and the workpiece W moves sequentially to the positioning area A1, the imaging area A2, and the discharge area A3.

In the following description, the vertical direction may be referred to as the Z direction (first direction), the direction in which the workpiece W is transported by the conveyor 11 as the X direction, and the direction intersecting the Z direction and the X direction as the Y direction. Figures 1, 3(a), and 3(c) show the configuration of the inspection unit 10 as viewed from above (as viewed from the Z direction). Figures 3(b) and 3(e) show the configuration of the inspection unit 10 as viewed from the Y direction. Figure 3(d) shows the configuration of the inspection unit 10 as viewed from the X direction.

As shown in FIG. 3(b), the support surface 16a, which is the surface of the support portion 16 that supports the workpiece W, is formed in a V-shape with the center recessed downward to correspond to the arched shape of the workpiece W (specifically, the shape of the outer rounded surface Wo). That is, the support surface 16a is recessed downward as it approaches the center in the X direction. The support surface 16a may be in contact with the outer rounded surface Wo of the workpiece W over substantially the entire surface, or as shown in FIG. 3(b), it may be in contact with the outer rounded surface Wo at both end sides in the X direction and not in contact with the outer rounded surface Wo at the center surface in the X direction.

As shown in Fig. 3(b) and Fig. 3(d), the positioning jig 20 is a holding jig that holds down the workpiece W transported to the positioning area A1 upstream of the imaging area A2 on the transport path from above and positions the workpiece W in the Y direction, which is the front-rear direction. As shown in Fig. 3(d), the positioning jig 20 has a flat body 20a and protrusions 20b, 20c that are provided at both ends of the body 20a in the Y direction and extend downward. The positioning jig 20 approaches the workpiece W transported to the positioning area A1 from above in response to the control of the controller 90, holds down the workpiece W downward with the body 20a, and holds down the workpiece W from both ends in the Y direction with the protrusions 20b, 20c. As shown in Figures 3(d) and 3(e), the main body 20a of the positioning jig 20 presses the workpiece W downward, correcting the rolling misalignment of the workpiece W (misalignment in the direction in which the arch-shaped workpiece W rotates), and the protrusions 20b and 20c press the workpiece W from both ends in the Y direction, correcting the positional misalignment of the workpiece W in the Y direction.

Returning to FIG. 1, the camera 12 is an imaging unit that faces the workpiece W transported to the imaging area A2 in the Z direction (first direction) and images the workpiece W. The camera 12 captures images by receiving a control signal from the controller 90. The camera 12 transmits the captured image to the controller 90.

The multiple mirrors 13 are composed of four mirrors 13a, 13b, 13c, and 13d. Each mirror 13a, 13b, 13c, and 13d is an optical element such as a prism. When viewed in the Z direction (first direction), each mirror 13a, 13b, 13c, and 13d is arranged to surround the workpiece W transported to the imaging area A2, and reflects the image of the workpiece W toward the imaging surface of the camera 12. Each mirror 13a, 13b, 13c, and 13d is arranged at each of the four corners of the workpiece W, which is approximately rectangular when viewed in the Z direction, and reflects the image of the corners. As shown in FIG. 1, when viewed in the Z direction, each mirror 13a, 13b, 13c, and 13d is arranged at a position that is 45° with respect to the X direction and the Y direction. By providing mirrors 13a, 13b, 13c, and 13d in this manner, the image of the workpiece W is reflected toward the imaging surface of camera 12 with respect to the two sides (two sides viewed in the Z direction) that are close to the corners of the workpiece W.

The mirror opening/closing mechanism 14 is a moving mechanism configured to be able to move the multiple mirrors 13a and 13b to open and close. The mirror opening/closing mechanism 15 is a moving mechanism configured to be able to move the multiple mirrors 13c and 13d to open and close. The mirror opening/closing mechanisms 14 and 15 perform opening and closing operations by receiving control signals from the controller 90.

Figures 4(a) and 4(b) are diagrams explaining the operation of the mirror opening and closing mechanisms 14 and 15. As shown in Figures 4(a) and 4(b), the mirror opening and closing mechanism 14 has a drive unit 14a that has a power source such as an actuator and is movable along the Y direction, and a connecting unit 14b that is connected to the drive unit 14a and is also connected to the mirrors 13a and 13b. The mirror opening and closing mechanism 15 has a drive unit 15a that has a power source such as an actuator and is movable along the Y direction, and a connecting unit 15b that is connected to the drive unit 15a and is also connected to the mirrors 13c and 13d.

Figure 4 (a) shows a state in which the drive units 14a and 15a have moved in a direction away from the transport path in response to control from the controller 90. In this state, the multiple mirrors 13a, 13b, 13c, and 13d are positioned away from the transport path of the workpiece W, so that the multiple mirrors 13a, 13b, 13c, and 13d do not interfere with the transport of the workpiece W.

Figure 4 (b) shows a state in which the drive units 14a and 15a have moved in the direction of the transport path (specifically, in the direction of the imaging area A2) in response to control from the controller 90. In this state, multiple mirrors 13a, 13b, 13c, and 13d are arranged close to the workpiece W, so that the frame can be made small during imaging, enabling imaging of the workpiece W at high resolution (high pixel count).

Returning to FIG. 1, the first lighting 17 is disposed above the workpiece W transported to the imaging area A2 and is a lighting that irradiates light onto the workpiece W. The second lighting 18, 19 is disposed below the workpiece W transported to the imaging area A2 and is a lighting that irradiates light onto the workpiece W.

Figure 5 is a diagram explaining the first lighting 17 and the second lighting 18, 19. As shown in Figure 5, the first lighting 17 is arranged below the camera 12 and above the workpiece W, and is formed in a ring shape so as not to block the space between the camera 12 and the workpiece W. The second lighting 18 is arranged below the workpiece W (see Figure 5) so as to illuminate the surface of the workpiece W on the side where the image is reflected by the multiple mirrors 13a, 13b from below (see Figure 1). The second lighting 19 is arranged below the workpiece W (see Figure 5) so as to illuminate the surface of the workpiece W on the side where the image is reflected by the multiple mirrors 13c, 13d from below (see Figure 1). For the second lighting 18, 19, for example, variable lighting is used, and the bottom surface of the workpiece W is entirely illuminated through a diffusion plate, making it possible to capture images without partial halation unevenness.

Figure 6 is a diagram showing an example of the image captured by the camera 12. As shown in Figure 6, the mirrors 13a, 13b, 13c, and 13d are positioned at 45° to the X and Y directions so as to surround the workpiece W, and the image is captured with light irradiated from the second lights 18 and 19 from below the workpiece W. This allows the single camera 12 to properly capture images of not only the inner rounded surface Wi of the workpiece W, but also the two sides adjacent to the corners of the workpiece W.

Returning to FIG. 1, the controller 90 is configured to be able to control each component included in the visual inspection device 1 to inspect a specified inspection surface of the workpiece W (control process), and to judge the surface condition of the workpiece W based on the inspection results (judgment process). The control process and judgment process will be described in detail below.

In the control process, the controller 90 first controls the conveyor 11 so that the workpiece W supported by the support portion 16 is transported along the transport path to the positioning area A1 and stopped at the positioning area A1 (performing the fifth control).

After the fifth control described above, the controller 90 controls the positioning jig 20 so that the workpiece W is positioned in the Y direction in the positioning area A1 as shown in Figures 3(b) and 3(d) (executes the sixth control).

After the sixth control described above, the controller 90 controls the conveyor 11 so that the workpiece W is transported to the imaging area A2 and stopped there, as shown in Figures 3(a) and 3(b), etc. (executing the first control).

After the first control described above, the controller 90 controls the mirror opening/closing mechanisms 14 and 15 so that the multiple mirrors 13a, 13b, 13c, and 13d move toward the imaging area A2, as shown in FIG. 4(b) (performing the second control).

After the second control described above, the controller 90 controls the camera 12 to capture an image of the workpiece W (performing the third control).

After the third control described above, the controller 90 controls the mirror opening/closing mechanisms 14 and 15 so that the multiple mirrors 13a, 13b, 13c, and 13d move in a direction away from the transport path including the imaging area A2 (performing the fourth control).

In the judgment process, the controller 90 judges whether the workpiece W is good or bad based on the image pickup result of the camera 12 in the third control described above (executes the seventh control). The controller 90 judges whether the information such as dimensions, area, and color shading shown in the image pickup result of the camera 12 is within a predetermined normal range. The controller 90 may judge whether the information such as dimensions, area, and color shading is normal (similar to the master image) by comparing the image pickup result of the camera 12 with a master image which is an image of a good workpiece W. Among the defective items, for example, chips, cracks, sand holes, and burrs can be judged according to the dimensions shown in the image pickup result of the camera 12. In addition, for example, stains can be judged according to the shading and area shown in the image pickup result of the camera 12. In addition, for example, black spots, polishing defects, and cutting defects can be judged using the image pickup result of the camera 12. Specifically, black spots can be judged from the area shown in the image pickup result, polishing defects can be judged from the width shown in the image pickup result, and cutting defects can be judged from the dimensions shown in the image pickup result.

The controller 90 may perform various pass/fail judgments in a predetermined order, and when any of the pass/fail judgments result in a failure, may determine that the workpiece W is defective without performing any further pass/fail judgments. The controller 90 may specify the defective item for the workpiece W that is determined to be defective (e.g., black porosity, etc.), and may control the discharge of the workpiece W determined to be defective to a discharge position for each defective item.

When determining whether the workpiece W is a quality product, the controller 90 may perform a division correction process to correct the dimensions by multiplying the reduction rate according to the distance from the corner of the workpiece W, and then determine whether the workpiece W is a quality product.

Figure 7 is a diagram explaining the division correction process. For the periphery of the corner of the workpiece W, the area is divided into five and the reduction rate is multiplied for each area, so that the actual dimensions are estimated with high accuracy. In the example shown in Figure 7, the area around the corner of the workpiece W is divided into five areas. Specifically, for the two sides extending from the corner, the inspection area is set to 3 mm from the center of the workpiece W to the back side (the back side when viewed from the corner), and the area is divided into five areas including an area 3 mm (3 mm on each of the two sides) from the corner of the workpiece W and each area obtained by dividing the remaining inspection area in half on each of the two sides. Note that the divided areas may overlap by, for example, about 3 mm. For each of the five divided areas in this way, a reduction rate according to the distance from the corner is multiplied to estimate the dimensions. Specifically, in the example shown in FIG. 7, the area 3 mm from the corner is multiplied by a reduction rate of 98%, the area closer to the corner of the divided area is multiplied by a reduction rate of 94%, and the area closer to the center of the divided area is multiplied by a reduction rate of 82%, and the dimensions of each area are estimated. These reduction rates may be set based on actual verification results. If a defect is detected where the areas overlap, the smaller of the reduction rates of the divided areas may be multiplied.

The hardware of the controller 90 is composed of, for example, one or more control computers. The controller 90 has, for example, a circuit 900 shown in FIG. 8 as a hardware configuration. The circuit 900 has a processor 901, a memory 902, a storage 903, an input/output port 904, and a driver 905. The driver 905 is a circuit for driving various actuators of the inspection unit 10. In addition to inputting and outputting external signals, the input/output port 904 also inputs and outputs signals to and from the driver 905. The processor 901 executes a program in consultation with at least one of the memory 902 and the storage 903, and inputs and outputs signals via the input/output port 904, thereby constituting the above-mentioned functional modules.

The hardware configuration of the controller 90 is not necessarily limited to configuring functional modules by executing a program. For example, the controller 90 may configure these functional modules using dedicated logic circuits or an ASIC (Application Specific Integrated Circuit) that integrates these circuits.

Next, the appearance inspection process (appearance inspection method) of the workpiece W using the appearance inspection device 1 will be described with reference to FIG. 9.

As shown in FIG. 9, in the visual inspection process, first, the workpiece W is conveyed on the conveyor 11 (step S1). The workpiece W is supported by the support portion 16 on the conveyor 11 and is transported by the conveyor 11 until it reaches the positioning area A1 (step S2). Then, in the positioning area A1, the positioning jig 20 holds down the workpiece W from above and positions the workpiece W in the Y direction, which is the front-to-rear direction (step S3).

Then, the workpiece W is transported by the conveyor 11 to the imaging area A2 where it stops (step S4, first process). Then, the mirror opening/closing mechanisms 14 and 15 perform a mirror closing movement in which the multiple mirrors 13a, 13b, 13c, and 13d move in the direction of the transport path (specifically, in the direction of the imaging area A2) (step S5, second process).

Then, a camera inspection is performed in which the workpiece W is imaged by the camera 12 (step S6, third process). After that, the mirror opening/closing mechanisms 14 and 15 perform a mirror leg movement in which the multiple mirrors 13a, 13b, 13c, and 13d move in a direction away from the transport path (direction away from the imaging area A2) (step S7, fourth process).

Then, a quality judgment of the workpiece W is performed based on camera inspection (step S8), and the defective workpiece W is rejected as a defective product (step S9), and the good workpiece W is rejected as a good product (step S10).

Next, we will explain the effects of the visual inspection device 1 according to this embodiment.

The appearance inspection device 1 according to this embodiment is an appearance inspection device that inspects the surface condition of a workpiece W, and includes a conveyor 11 configured to transport the placed workpiece W along a transport path to an imaging area A2, a camera 12 that faces the workpiece W transported to the imaging area A2 in the Z direction and captures an image of the workpiece W, a plurality of mirrors 13a, 13b, 13c, 13d that are arranged to surround the workpiece W transported to the imaging area A2 when viewed in the Z direction and reflect an image of the workpiece W toward the imaging surface of the camera 12, mirror opening and closing mechanisms 14, 15 configured to move the plurality of mirrors 13a, 13b, 13c, 13d, and a controller 90. The controller 90 is configured to execute a first control for controlling the conveyor 11 so that the workpiece W is transported to the imaging area A2 and stopped in the imaging area A2, a second control for controlling the mirror opening/closing mechanisms 14 and 15 so that the multiple mirrors 13a, 13b, 13c, and 13d move toward the imaging area A2 after the first control, a third control for controlling the camera 12 so that the workpiece W is imaged after the second control, and a fourth control for controlling the mirror opening/closing mechanisms 14 and 15 so that the multiple mirrors 13a, 13b, 13c, and 13d move in a direction away from the transport path including the imaging area A2 after the third control.

In the appearance inspection device 1 according to this embodiment, multiple mirrors 13a, 13b, 13c, 13d that reflect the image of the workpiece W toward the imaging surface of the camera 12 are arranged to surround the workpiece W transported to the imaging area, so that multiple surfaces of the workpiece W can be imaged with one camera 12. Compared to a configuration in which an imaging means is provided for each surface of the workpiece W, for example, costs are reduced and the imaging process is simplified by eliminating the need to switch the imaging means. In the appearance inspection device 1 according to this embodiment, when the workpiece W is stopped in the imaging area A2, the mirror opening/closing mechanisms 14, 15 are controlled so that the multiple mirrors 13a, 13b, 13c, 13d move in the direction of the imaging area A2, and then the camera 12 images the workpiece W. In this way, the multiple mirrors 13a, 13b, 13c, and 13d are moved toward the imaging area A2, and the workpiece W is imaged in this state, so that the multiple mirrors 13a, 13b, 13c, and 13d are close to the workpiece W when the workpiece W is imaged, and the image of the workpiece W is imaged in a state in which the image frame is made small, so that the image of the workpiece W can be imaged with high resolution (high pixel count). Furthermore, in the appearance inspection device 1 according to this embodiment, after the image is captured, the multiple mirrors 13a, 13b, 13c, and 13d are moved in a direction away from the transport path including the imaging area A2, so that the multiple mirrors 13a, 13b, 13c, and 13d are not placed on the transport path except when the image is captured (before and after the image is captured), and the multiple mirrors 13a, 13b, 13c, and 13d do not interfere with the transport of the workpiece W. As described above, according to the visual inspection device 1 of this embodiment, the mirror opening and closing mechanisms 14 and 15 move the multiple mirrors 13a, 13b, 13c, and 13d using the controller 90, ensuring transportability of the workpiece W and enabling the workpiece W to be imaged at high resolution.

The above-mentioned visual inspection device 1 further includes a support part 16 that supports the workpiece W transported to the imaging area A2, and at least the lower surface of the workpiece W is formed in an arch shape, and the surface of the support part 16 that supports the workpiece W may be formed in a V shape with the center concave downward to correspond to the shape of the workpiece W that is formed in an arch shape. In this way, since the surface of the support part 16 that supports the workpiece W is formed in a V shape along the shape of the part, when the support part 16 receives the workpiece W, it is effectively prevented that the workpiece W is placed on the support part 16 in a state where it is misaligned in the θ direction with respect to the axis of the support part 16.

The above-mentioned appearance inspection device 1 further includes a positioning jig 20 that holds down the workpiece W transported to the positioning area A1 upstream of the imaging area A2 on the transport path from above and positions it in the front-rear direction, and the controller 90 may be configured to further execute a fifth control for controlling the conveyor 11 so that the workpiece W is transported to the positioning area A1 and stopped at the positioning area A1 before the first control, and a sixth control for controlling the positioning jig 20 so that the workpiece W is held down after the fifth control and before the first control. If the position (orientation) of the workpiece W transported to the imaging area A2 is different from the expected position (orientation), it may not be possible to inspect the workpiece W after imaging with high accuracy. For example, position correction of the workpiece W may be performed using image software, but even if such position correction is performed, the inspection accuracy of the workpiece W may not be sufficiently guaranteed. In this regard, in the positioning area A1 upstream of the imaging area A2, the positioning jig 20 holds down the workpiece W and positions the workpiece W in the front-to-rear direction (i.e., actually corrects the position of the workpiece W rather than performing software correction), thereby improving the inspection accuracy based on the imaging results in the imaging area A2. Specifically, the positioning jig 20 holds down the workpiece W from above, correcting the rolling misalignment of the workpiece W (misalignment in the direction in which the arch-shaped workpiece W rotates), and the positioning jig 20 positions the workpiece W in the front-to-rear direction, correcting the front-to-rear misalignment of the workpiece W, thereby improving the inspection accuracy.

The workpiece W is approximately rectangular when viewed in the Z direction, and the multiple mirrors 13a, 13b, 13c, and 13d may be configured to include four mirrors 13a, 13b, 13c, and 13d that are arranged at each of the four corners of the workpiece W when viewed in the Z direction and reflect images of the corners. By arranging each mirror 13a, 13b, 13c, and 13d at the corners in this manner, each mirror 13a, 13b, 13c, and 13d can capture images of two sides close to the corners (two sides when viewed in the Z direction), so that each surface of the workpiece W can be properly imaged.

The controller 90 is further configured to execute a seventh control for determining whether the workpiece W is good or bad based on the image capturing result of the camera 12 in the third control. In the seventh control, the quality of the workpiece W may be determined after performing a correction process for correcting the dimensions by multiplying the reduction rate according to the distance from the corner of the workpiece W. By performing such a correction process, the actual dimensions can be estimated with high accuracy taking into account the distance from the corner, and the accuracy of the quality determination of the workpiece W can be improved.

The above-mentioned appearance inspection device 1 may further include a first illuminator 17 arranged above the workpiece W transported to the imaging area A2 and irradiating light onto the workpiece W, and second illuminators 18, 19 arranged below the workpiece W transported to the imaging area A2 and irradiating light onto the workpiece W. By providing the second illuminators 18, 19 that irradiate light from below the workpiece W in addition to the first illuminator 17 that irradiates light from above the workpiece W, light can be appropriately irradiated onto the underside (bottom surface) of the workpiece W, which is difficult to irradiate with light when only the first illuminator 17 is provided, and imaging results that tend to improve inspection accuracy can be obtained.

1...visual inspection device, 11...conveyor (transport section), 12...camera (imaging section), 13a, 13b, 13c, 13d...mirror, 14, 15...mirror opening/closing mechanism (movement mechanism), 16...support section, 17...first lighting, 18, 19...second lighting, 20...positioning jig (holding jig), 90...controller (control device), A1...positioning area, A2...imaging area, W...work (component).

Claims (5)

A visual inspection device for inspecting a surface condition of a part, comprising:
a conveying unit configured to convey the placed part along a conveying path to an imaging area;
an imaging unit that faces the component conveyed to the imaging area in a first direction and images the component;
a plurality of mirrors that are arranged to surround the component transported to the imaging area when viewed in the first direction, and that reflect an image of the component toward an imaging surface of the imaging unit;
a moving mechanism configured to be able to move the plurality of mirrors;
A control device,
The control device includes:
a first control for controlling the transport unit so that the component is transported to the imaging area and stopped at the imaging area; a second control for controlling the moving mechanism so that the multiple mirrors move toward the imaging area after the first control; a third control for controlling the imaging unit so that the component is imaged after the second control; and a fourth control for controlling the moving mechanism so that the multiple mirrors move in a direction away from the transport path including the imaging area after the third control ,
a support unit that supports the component to be transported to the imaging area;
At least a lower surface of the component is formed in an arch shape,
a surface of the support portion that supports the component is formed in a V-shape with a central portion concave downward so as to correspond to a shape of the component that is formed in an arch shape,
a pressing tool that presses down the part conveyed to a positioning area upstream of the imaging area on the conveying path from above and positions the part in a front-rear direction,
The control device is configured to further execute a fifth control of controlling the transport section so that the part is transported to the positioning area and stopped at the positioning area before the first control, and a sixth control of controlling the pressing jig so that the part is pressed down after the fifth control and before the first control . A visual inspection device for inspecting a surface condition of a part, comprising:
a conveying unit configured to convey the placed part along a conveying path to an imaging area;
an imaging unit that faces the component conveyed to the imaging area in a first direction and images the component;
a plurality of mirrors that are arranged to surround the component transported to the imaging area when viewed in the first direction, and that reflect an image of the component toward an imaging surface of the imaging unit;
a moving mechanism configured to be able to move the plurality of mirrors;
A control device,
The control device includes:
a first control for controlling the transport unit so that the component is transported to the imaging area and stopped at the imaging area; a second control for controlling the moving mechanism so that the multiple mirrors move toward the imaging area after the first control; a third control for controlling the imaging unit so that the component is imaged after the second control; and a fourth control for controlling the moving mechanism so that the multiple mirrors move in a direction away from the transport path including the imaging area after the third control,
The component has a substantially rectangular shape when viewed in the first direction,
the plurality of mirrors include four mirrors that are disposed at four corners of the component as viewed in the first direction and that reflect images of the corners;
The control device is configured to further execute a seventh control for determining whether the component is good or bad based on an imaging result of the imaging unit in the third control,
In the seventh control, a correction process is performed to correct the dimensions by multiplying the dimensions by a reduction rate according to the distance from the corner of the component, and then the component is judged to be a non-defective product. a first illuminator that is disposed above the component transported to the imaging area and irradiates the component with light;
3. The visual inspection apparatus according to claim 1, further comprising: a second illuminator arranged below the component transported to the imaging area and configured to irradiate the component with light. A visual inspection method for inspecting a surface condition of a part, comprising the steps of:
a first step of conveying the part along a conveying path to an imaging area by a conveying unit and stopping the part in the imaging area;
a second step of moving, by a moving mechanism after the first step, a plurality of mirrors arranged to surround the component transported to the imaging area toward the imaging area;
a third step of capturing an image of the component by an imaging unit after the second step;
a fourth step of moving the plurality of mirrors in a direction away from the imaging area by the moving mechanism after the third step ,
At least a lower surface of the component is formed in an arch shape,
a surface of a support part for supporting the component to be transported to the imaging area is formed in a V-shape with a central portion concave downward so as to correspond to a shape of the component which is formed in an arch shape,
a fifth step of conveying the part by the conveying unit to a positioning area upstream of the imaging area on the conveying path and stopping the part in the positioning area before the first step;
The visual inspection method further includes a sixth step of holding down the part transported to the positioning area with a holding jig that holds down the part from above and positions it in the front-to-back direction after the fifth step and before the first step . A visual inspection method for inspecting a surface condition of a part, comprising the steps of:
a first step of conveying the part along a conveying path to an imaging area by a conveying unit and stopping the part in the imaging area;
a second step of moving, by a moving mechanism after the first step, a plurality of mirrors arranged to surround the component transported to the imaging area toward the imaging area;
a third step of capturing an image of the component by an imaging unit after the second step;
a fourth step of moving the plurality of mirrors in a direction away from the imaging area by the moving mechanism after the third step,
The component has a substantially rectangular shape when viewed in a first direction in which the component and the imaging unit face each other,
the plurality of mirrors include four mirrors that are disposed at four corners of the component as viewed in the first direction and reflect images of the corners;
A seventh step of determining whether the component is good or bad based on the imaging result of the imaging unit in the third step,
In the seventh step, a correction process is performed to correct the dimensions by multiplying the dimensions by a reduction rate according to the distance from the corner of the component, and then the component is judged to be a non-defective product.