Image inspecting device

Abstract

To provide an image inspecting device for increasing position measurement precision of an alignment section.SOLUTION: An alignment section 13 provided in an image inspection device so as to measure a work position comprises: a side face section 131a extending along a photographing direction D14; a higher section 131b that is reflected away from an edge 131a-1 in a side of a photographing section of the side face section 131a in a photographed image, and is positioned in a side of the photographing section relative to the edge 131a-1 for the photographing direction D14; and an inclined plane 131c that extends while being inclined from the edge 131a-1 of the side face section 131a to the higher section 131b, and turns inclined plane reflection light L121 toward a direction different from that of the photographing section side.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image inspection device that photographs a workpiece and performs inspection using the photographed image. [Background technology]

[0002] Conventionally, image inspection devices that photograph and inspect workpieces have been widely used (see, for example, Patent Document 1). The image inspection device described in Patent Document 1 photographs a semiconductor wafer as a workpiece and performs inspection through the photographed image. In this device, an alignment unit is provided at a position that appears in the photographed image together with the wafer as the workpiece, and inspection is performed for distortion, tilt, etc. of the photographed image based on the alignment unit that appears in the photographed image. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-194378 Summary of the Invention [Problem to be solved by the invention]

[0004] To carry out the above-described processing, it is necessary to measure the position of the alignment unit in the captured image. At this time, the accuracy of the alignment unit position measurement may be reduced due to, for example, similarity between the color of the alignment unit and the background color in the captured image, or unclearness of the outline of the alignment unit. Furthermore, a reduction in the accuracy of the alignment unit position measurement may increase errors in workpiece position measurement based on the alignment unit position measurement, which is undesirable.

[0005] Therefore, the present invention focuses on the above-mentioned problems and aims to provide an image inspection device that can improve the position measurement accuracy of an alignment unit. [Means for solving the problem]

[0006] In order to solve the above problems, the image inspection device comprises an alignment unit for measuring the position of the workpiece, which is positioned in a position that appears in the captured image together with the workpiece to be inspected; an illumination unit that irradiates illumination light onto the workpiece and the alignment unit; and an imaging unit that takes an image by receiving light reflected from the illumination light reflected by the workpiece and the alignment unit, wherein the alignment unit comprises a side portion extending along the imaging direction by the imaging unit, a high portion that appears away from the edge of the side portion on the imaging unit side in the captured image and is located closer to the imaging unit than the edge in the imaging direction, and an inclined surface that extends at an angle from the edge to the high portion, and directs the reflected light at the surface portion in a direction different from the imaging unit side. [Effects of the Invention]

[0007] According to the image inspection device described above, the accuracy of measuring the position of the alignment unit can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an image inspection device according to a first embodiment. [Figure 2] 2 is a diagram showing a state in which a twisted shielded pair electric wire is set as a work to be inspected in the image inspection device shown in FIG. 1. FIG. [Figure 3] FIG. 3 is an enlarged perspective view showing one of the alignment sections shown in FIGS. 1 and 2. [Figure 4] 3 is a schematic diagram showing how light emitted from the ring illumination of the first illumination unit is reflected by the pair of alignment units shown in FIGS. 1 and 2, and how part of the reflected light travels toward the imaging unit. FIG. [Figure 5] FIG. 5 is an enlarged view of a pair of alignment portions shown in FIG. 4. [Figure 6] 2 is a schematic flowchart showing the flow of a process for measuring the position of a workpiece performed by the image inspection device shown in FIG. 1; [Figure 7] FIG. 2 is a schematic diagram showing an image captured by the image inspection device shown in FIG. 1. [Figure 8] FIG. 10 is a diagram showing an alignment unit in an image inspection device according to a second embodiment, together with a twisted shielded pair electric wire set as a work to be inspected. [Figure 9] FIG. 9 is a schematic diagram showing an image captured by the image inspection device shown in FIG. 8. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of an image inspection device will be described below. First, a first embodiment will be described.

[0010] FIG. 1 is a perspective view showing an image inspection device according to the first embodiment, and FIG. 2 is a diagram showing how a twisted shielded pair electric wire is set as a work to be inspected in the image inspection device shown in FIG. 1.

[0011] The image inspection device 1 of this embodiment is an apparatus that photographs a twisted shielded pair electric wire W1 shown in Fig. 2 as a workpiece and measures the position of the workpiece in the photographed image. In this embodiment, the twisted shielded pair electric wire W1 has two electric wires W11 as core wires exposed in an untwisted state at one end thereof, and the end coating of each electric wire W11 is removed to form an exposed conductor portion W12. The image inspection device 1 includes a stand frame 11, a workpiece holder 12, an alignment unit 13, a first illumination unit 14, an imaging unit 15, a second illumination unit 16, and a processing unit 17.

[0012] The stand frame 11 is installed at a predetermined inspection location and is a frame member that supports the workpiece holder 12, the first illumination unit 14, the photographing unit 15, and the second illumination unit 16, and includes a base portion 111 and a support column portion 112. The base portion 111 is a rectangular plate-shaped portion that is placed at the inspection location, and the support column portion 112 is erected on its upper surface, and the second illumination unit 16 is attached to it. The support column portion 112 is an erect rectangular strip-shaped plate member with one end fixed to the base portion 111. The workpiece holder 12, the first illumination unit 14, and the photographing unit 15 are supported on one surface of the support column portion 112 by screws or the like.

[0013] The workpiece holder 12 is a component that chucks and holds the vicinity of the exposed wire portion of the outermost sheath portion W13 of the twisted shielded pair electric wire W1, and includes a plate portion 121, a wire chuck portion 122, and an alignment holder 123. The plate portion 121 is a rectangular plate-shaped member, and one short side thereof is supported by the support column portion 112. The central portion of the plate portion 121 that overlaps with the second illumination unit 16 when viewed from the imaging unit 15 forms a rectangular window 121a covered with a transparent plate. The wire chuck portion 122 is fixed near the end of the rectangular window 121a on the opposite side from the support column portion 112, and the alignment holder 123 is fixed near the end on the support column portion 112 side. The alignment holder 123 is fixed in a state in which the relative distance between it and the wire chuck portion 122 is adjustable. The wire chuck portion 122 is a member that clamps and holds the vicinity of the exposed wire portion of the outermost sheath portion W13 of the twisted shielded pair electric wire W1 in a chuck direction D12 along the longitudinal direction D11 of the support pole portion 112. The wire chuck portion 122 clamps and holds the twisted shielded pair electric wire W1 between a first chuck 122a located on the plate portion 121 side and a second chuck 122b located on the imaging unit 15 side. Note that FIG. 2 shows the wire chuck portion 122 with the second chuck 122b removed so that the twisted shielded pair electric wire W1 to be held can be seen. The twisted shielded pair electric wire W1 held by the wire chuck portion 122 is held on the imaging unit 15 side of the rectangular window 121a of the plate portion 121 so that the exposed conductor portions W12 of the two electric wires W11 face toward the alignment holding portion 123. The alignment holding portion 123 is a member that holds the pair of alignment portions 13 at a position spaced a predetermined distance from the exposed conductor portion W12 at the tip of the two electric wires W11 in the twisted shielded pair electric wire W1.

[0014] The pair of alignment units 13 are a pair of members for measuring the position of a workpiece, and are arranged by the alignment holder 123 at a position where they will appear in a captured image together with the twisted shielded pair electric wire W1, which is the workpiece to be inspected. The pair of alignment units 13 are arranged on the capturing unit 15 side of the rectangular window 121a of the plate unit 121 together with the two electric wires W11 of the twisted shielded pair electric wire W1. The alignment units 13 will be described again later with reference to another drawing.

[0015] The first illumination unit 14 includes an illumination holding plate 141 and a ring illumination 142. The illumination holding plate 141 is a sheet metal member bent into an L-shape in side view, and a support portion 141a corresponding to the short side of the L-shape is supported by the support column portion 112. The ring illumination 142 is fixed to an illumination fixing portion 141b corresponding to the long side of the L-shape. The illumination holding plate 141 is supported by the support column portion 112 so that the illumination fixing portion 141b and the ring illumination 142 are positioned between the workpiece holder 12 and the imaging unit 15. This support is achieved by fixing the support portion 141a with screws in a state where its position can be adjusted in the length direction D11 of the support column portion 112. A circular imaging window 141c for the imaging unit 15 is formed through the illumination fixing portion 141b in a portion that corresponds to the inside of the ring illumination 142. The ring light 142 is located between the twisted shielded pair electric wire W1 as the workpiece and the pair of alignment units 13 and the photographing unit 15, and irradiates the workpiece and alignment unit 13 with illumination light in a ring shape from the photographing unit 15 side.

[0016] The photographing unit 15 photographs the two electric wires W11 of the twisted shielded pair electric wire W1 as the workpiece together with the pair of alignment units 13 through the photographing window 141c of the light holding plate 141. The photographing at this time is performed under illumination from the ring light 142, and the photographing unit 15 receives light reflected from the twisted shielded pair electric wire W1 and the alignment unit 13. The photographing unit 15 includes a camera holding unit 151, a camera 152, and a photographing lens 153. The camera holding unit 151 is fixed to the tip of the support column portion 112 and holds the camera 152 at a position where it can photograph through the photographing window 141c of the light holding plate 141. The camera 152 is a component that captures the reflected light and photographs the workpiece, and holds a cylindrical photographing lens 153 facing the photographing window 141c. The photographing lens 153 is a component that collects the reflected light that passes through the photographing window 141c and sends it to the camera 152.

[0017] The second illumination unit 16 is a member with a rectangular block-like appearance that is fixed to the opposite side of the photographing unit 15 from the twisted shielded pair electric wires W1 and the alignment unit 13, specifically to the upper surface of the base portion 111 of the stand frame 11. The second illumination unit 16 irradiates background light from its light-emitting surface 161 on the photographing unit 15 side, over the twisted shielded pair electric wires W1 and the alignment unit 13, to the photographing unit 15.

[0018] In this image inspection device 1, the photographing unit 15 photographs the twisted shielded pair electric wire W1 and the alignment unit 13 while illuminating them with irradiation light from the ring illumination 142 of the first illumination unit 14 and background light from the second illumination unit 16. Then, in the photographed image, work position measurement of the twisted shielded pair electric wire W1 as the work is performed, and the image of the alignment unit 13 is used for this work position measurement.

[0019] The processing unit 17 is a control part that controls the operation of each unit in the image inspection device 1 and also performs various inspection processes through image analysis of the image captured by the imaging unit 15.

[0020] Fig. 3 is an enlarged perspective view of one of the alignment units shown in Fig. 1 and Fig. 2. Fig. 4 is a schematic diagram showing how the light emitted from the ring illumination of the first illumination unit is reflected by the pair of alignment units shown in Fig. 1 and Fig. 2, and how part of the reflected light travels toward the imaging unit. Fig. 5 is an enlarged view of the pair of alignment units shown in Fig. 4.

[0021] 3 to 5, the alignment part 13 includes an alignment body 131 and an insertion protrusion 132. The insertion protrusion 132 is a round bar-shaped protrusion that protrudes from the alignment body 131 along the axial direction D13 toward the side opposite to the reflection side of the irradiated light L11. The alignment part 13 is attached to and held by the alignment holding part 123 by driving and inserting the insertion protrusion 132 into an insertion hole in the alignment holding part 123.

[0022] On the other hand, the alignment body 131 is a round bar-shaped pin portion having a larger diameter than the fitting protrusion 132, and includes a side portion 131a, a high portion 131b, and an inclined surface 131c. The side portion 131a is a cylindrical circumferential surface portion extending in an imaging direction D14 by the imaging unit 15 along the longitudinal direction D11 of the support pillar portion 112. The high portion 131b is a portion that appears apart from an edge 131a-1 of the side portion 131a on the imaging unit 15 side in the captured image, and is located closer to the imaging unit 15 than the edge 131a-1 in the imaging direction D14. The inclined surface 131c is a surface portion that extends at an angle from the edge 131a-1 of the side portion 131a to the high portion 131b. As shown in FIGS. 4 and 5, the inclined surface 131c directs the inclined surface reflected light L121, which is the illumination light L11 from the ring illumination 142, in a direction different from the photographing unit 15 side.

[0023] In this embodiment, the alignment unit 13 is a pin member arranged with the tip of the alignment body 131 facing the imaging unit 15, and a high portion 131b and an inclined surface 131c are formed at the tip. The inclined surface 131c is a convex curved surface that curves convexly from the edge 131a-1 of the side surface 131a to the high portion 131b. Specifically, the tip of the alignment body 131 in the alignment unit 13 as a pin member is part of a sphere, more specifically a hemisphere, with the apex of the hemisphere being the high portion 131b. Furthermore, the fitting protrusion 132 of the alignment unit 13 is driven and fitted into the fitting hole of the alignment holder 123 by striking the apex of this hemisphere. By striking in this manner, the top of the hemispherical surface becomes a flat high-level portion 131b, and the surrounding spherical surface surrounding this high-level portion 131b becomes an inclined surface 131c as a convex curved surface.

[0024] Of the reflected light L12 produced when illumination light L11 from ring illumination 142 is reflected at the tip of alignment body 131, inclined surface reflected light L121 reflected at inclined surface 131c as described above travels in a direction different from the photographing unit 15. On the other hand, high-level portion reflected light L122 reflected at high-level portion 131b, which has become a flat surface, travels toward photographing unit 15 and is taken in.

[0025] In this embodiment, a pair of such alignment units 13 are provided as shown in Fig. 1. The pair of alignment units 13 are arranged at positions away from the tips of the two electric wires W11 of the twisted shielded pair electric wire W1 held by the electric wire chuck unit 122, so as to sandwich the extension axis W1a of the twisted shielded pair electric wire W1 between them. In the image inspection device 1 of this embodiment, measurement of the position of a workpiece in a captured image using such alignment units 13 is performed as follows under processing by the processing unit 17.

[0026] Figure 6 is a schematic flowchart showing the processing flow of work position measurement performed under the processing of the processing unit in the image inspection device shown in Figure 1, and Figure 7 is a schematic diagram showing a captured image taken by the image inspection device shown in Figure 1.

[0027] In the image inspection device 1, imaging is basically performed under illumination by the irradiation light L11 from the ring illumination 142 and the background light from the second illumination unit 16, but imaging under illumination by only the background light is also possible. In Figure 7, Figure 7(A) shows an image G11 obtained under illumination by the irradiation light L11 from the ring illumination 142 and the background light from the second illumination unit 16, and Figure 7(B) shows an image G12 obtained under illumination by only the background light. The state under which imaging is performed is determined by the control by the processing unit 17 over the ring illumination 142 of the first illumination unit 14, the second illumination unit 16, and the imaging unit 15.

[0028] First, under processing by the processing unit 17, the twisted shielded pair electric wire W1 is set as a workpiece in the electric wire chuck unit 122 of the image inspection device 1, and then an image is taken (step S11). When this image is taken under illumination with the irradiation light L11 from the ring light 142 and the background light from the second illumination unit 16, a captured image G11 shown in FIG. 7(A) is obtained. In this captured image G11, the twisted shielded pair electric wire W1 and a part of the alignment holding unit 123 appear bright. On the other hand, in the image of the pair of alignment units 13 sandwiching the extension axis W1a of the twisted shielded pair electric wire W1 between them, the image portion of the inclined surface 131c at the tip appears dark because the inclined surface reflected light L121 is directed in a direction different from the photographing unit 15. Note that because the central high-level portion 131b is a flat surface directed toward the photographing unit 15, the image portion of this high-level portion 131b appears bright.

[0029] On the other hand, if the image is captured under background light only, the captured image G12 shown in Fig. 7(B) is obtained. In this captured image G12, the twisted shielded pair electric wire W1, part of the alignment holding portion 123, and the pair of alignment portions 13 all appear as black silhouettes due to the background light.

[0030] When at least one of the captured images G11, G12 is obtained in this manner, the processing unit 17 performs image analysis on the captured images G11, G12 to extract images of the pair of alignment portions 13 (step S12). Then, the processing unit 17 calculates the coordinates of the centers 131d of the pair of alignment portions 13 based on the extracted images of the alignment portions 13 (circular images in this embodiment) (step S13). Furthermore, in step S13, the processing unit 17 determines an alignment line 131e connecting the pair of centers 131d. Then, when the horizontal edges of the captured images G11, G12 are set as reference lines G11-1, G12-1, the inclination angle of the alignment line 131e with respect to the reference lines G11-1, G12-1 is calculated as the alignment angle.

[0031] Next, the captured images G11 and G12 are analyzed by the processing unit 17 to extract an image of the twisted shielded pair electric wire W1 as the work (step S14). Then, the processing unit 17 calculates a distance T11 between the tip ends of the two electric wires W11 in the extracted twisted shielded pair electric wire W1 and the alignment line 131e obtained in step S13 as a result of work position measurement (step S15).

[0032] According to the image inspection device 1 of the first embodiment described above, the shape of the alignment unit 13 for workpiece position measurement on the side of the imaging unit 15 includes a high portion 131b and an inclined surface 131c, and illumination light L11 from the first illumination unit 14 is reflected by these portions. The image of the alignment unit 13 in the captured image G11 is an image based mainly on the inclined surface reflected light L121 and the high portion reflected light L122. At this time, the inclined surface reflected light L121 is reflected in a direction away from the imaging unit 15 due to the inclination of the inclined surface 131c, and appears black in the captured image G11. That is, in the captured image G11, the portion of the alignment unit 13 near the edge 131a-1 of the side surface 131a appears black and stands out clearly against the background image, with its outline clearly defined. Based on the image of the alignment section 13 with a clear outline, the accuracy of position measurement such as calculation of the coordinates of the center 131d of the alignment section 13 can be improved.

[0033] In this embodiment, a second illumination unit 16 is provided that irradiates background light onto the photographing unit 15 through the twisted shielded pair electric wire W1 as the workpiece and the alignment unit 13. With this configuration, the background of the alignment unit 13 in the photographed image G11 is dominated by the background light from the second illumination unit 16. As a result, the contour of the black image near the edge 131a-1 of the side surface 131a of the alignment unit 13 is further sharpened, and this sharpened contour can further improve the position measurement accuracy. Alternatively, a silhouette image as shown in FIG. 7(B) can be obtained by photographing with only background light irradiated, and the clear contour can be extracted to further improve the position measurement accuracy.

[0034] In this embodiment, the inclined surface 131c is a convex curved surface. With this configuration, the convex curved surface effectively directs the inclined surface reflected light L121 away from the photographing unit 15, thereby further sharpening the outline of the black image of the alignment unit 13 in the photographed image G11.

[0035] In this embodiment, the alignment portion 13 is a pin member, and a high portion 131b and an inclined surface 131c are formed at the tip of the pin member. This configuration is preferable because, for example, the center 131d of the tip of the pin member can be used as a reference for measuring the position of the workpiece.

[0036] In this embodiment, the tip of the pin member serving as alignment portion 13 is part of a spherical surface with its apex being the high portion 131b. With this configuration, the tip of the pin member serving as alignment portion 13 appears as a circular image with a clear outline in captured image G11, which is preferable because it is easier to use its center 131d as a reference for measuring the workpiece position.

[0037] This concludes the description of the first embodiment, and next we will describe the second embodiment. This second embodiment differs from the first embodiment in the shape of the alignment portion. Below, we will describe the second embodiment, focusing on the differences from the first embodiment.

[0038] Fig. 8 is a diagram showing an alignment unit in an image inspection device according to a second embodiment, together with a twisted shielded pair electric wire set as a workpiece to be inspected. Fig. 9 is a schematic diagram showing an image captured by the image inspection device shown in Fig. 8. In Figs. 8 and 9, components equivalent to those of the first embodiment shown in Figs. 1 to 5 and 7 are assigned the same reference numerals as in Figs. 1 to 5 and 7. In the following description, a duplicated description of these equivalent components will be omitted. In the following description, components shown in Figs. 1 to 5 and 7 will be referred to without any reference to their respective figure numbers.

[0039] The alignment unit 23 in the image inspection device 2 of this embodiment is a generally rectangular block member having a flat surface formed as a higher portion 231b on the imaging unit 15 side. The alignment unit 23 is disposed in an upright position like a partition intersecting the extension axis W1a of the twisted shielded pair electric wire W1 near the end of the rectangular window 121a provided in the plate portion 121 of the workpiece holder 12 on the support column portion 112 side. The alignment unit 23 also has a rectangular groove 232 formed along the upright direction D21 on the workpiece-side side surface 231a facing the tips of the two electric wires W11 of the twisted shielded pair electric wire W1. A pair of inclined surfaces 231c are formed on either side of the rectangular groove 232, extending from at least a portion of the periphery of the flat higher portion 231b, specifically from the workpiece-side edge portion 231b-1 to the edge 231a-1 of the workpiece-side side surface 231a. The location where the inclined surface 231c of this alignment unit 23 is formed is the corner edge of the rectangular block on the imaging unit 15 side, and this corner edge is rounded to form the convex curved inclined surface 231c as a chamfered portion. In addition, the portion higher than this chamfered portion is a flat surface serving as a higher portion 231b.

[0040] The images obtained by photographing using this alignment unit 23 are as follows: In Fig. 9, which shows images obtained by photographing in this embodiment, Fig. 9(A) first shows a photographed image G21 obtained in a state illuminated by irradiation light L11 from ring illumination 142 and background light from second illumination unit 16. Fig. 9(B) also shows a photographed image G22 obtained in a state illuminated only by background light.

[0041] 9(A), the twisted shielded pair electric wire W1 and the flat surface serving as the high portion 231b of the alignment portion 23 appear bright. On the other hand, the pair of inclined surfaces 231c located on both sides of the rectangular groove 232, sandwiching the extension axis W1a of the twisted shielded pair electric wire W1 between them, appear dark because the inclined surface reflected light L121 is directed in a direction different from the photographing unit 15.

[0042] 9(B), in which only background light is present, the twisted shielded pair electric wire W1 and the alignment portion 23 all appear as black silhouettes due to the background light. Note that in the photographed image G22 of FIG. 9(B), the silhouettes of a pair of portions of the alignment portion 23 sandwiching the rectangular groove 232 are captured.

[0043] In workpiece position measurement based on these captured images G21 and G22, first, corner vertices 231d on the groove side of a pair of inclined surfaces 231c located on both sides of the rectangular groove 232 are determined as a reference for position measurement in the alignment unit 23. Then, the inclination angle of an alignment line L231e connecting the pair of corner vertices 231d relative to reference lines G21-1 and G22-1 of the lateral edges in the captured images G21 and G22 is calculated as the alignment angle. Also, a distance T21 between the tips of the two electric wires W11 of the twisted shielded pair electric wire W1 and the alignment line 231e is calculated as the result of the workpiece position measurement.

[0044] As in the first embodiment, the image inspection device 1 of the second embodiment described above also produces a black image of the portion of the alignment unit 23 near the edge 231a-1 of the side surface 231a that stands out clearly against the background image, with a clear outline. Based on the image of the alignment unit 23 with the clear outline, it is possible to improve the accuracy of position measurements, such as calculation of the coordinates of the corner vertex 231d of the alignment unit 23.

[0045] In this embodiment, the alignment portion 23 is a block member, and an inclined surface 231b is formed from at least a part of the periphery of the flat surface of the higher portion 231b to the side surface portion 231a on the workpiece side. With this configuration, the inclined surface 231b can be formed with fewer steps, for example, by chamfering the corner edge of the block member, and therefore the manufacturing cost of the alignment portion 23 can be reduced.

[0046] Furthermore, in this embodiment, the alignment unit 23 is a rectangular block member in which a corner edge portion on the imaging unit 15 side is rounded, and the portion higher than the chamfered portion is a flat surface serving as a higher portion 231b, and the chamfered portion is an inclined surface 231b. With this configuration, the convexly curved chamfered portion formed by the rounded chamfering of the corner edge portion becomes the inclined surface 231b. By making such a chamfered portion into the inclined surface 231b, the inclined surface reflected light L121 can be effectively directed away from the imaging unit 15, further sharpening the outline of the black image of the alignment unit 23 in the captured images G21 and G22.

[0047] The first and second embodiments described above are merely representative examples of the image inspection device, and the image inspection device is not limited to these and can be implemented in various modifications.

[0048] For example, in the first and second embodiments described above, image inspection devices 1 and 2 are exemplified as an example of an image inspection device, which photograph a twisted shielded pair electric wire W1 as a work and perform work position measurement. Furthermore, in the first embodiment, calculation of the distance T11 between the tip ends of the two electric wires W11 in the twisted shielded pair electric wire W1 and the alignment line 131e connecting the centers 131d of the pair of alignment portions 13 is exemplified as work position measurement. Furthermore, in the second embodiment, calculation of the distance T21 between the tip ends of the two electric wires W11 in the twisted shielded pair electric wire W1 and the alignment line L231e connecting the corner vertices 231d of the pair of alignment portions 23 is exemplified as work position measurement. However, the image inspection device is not limited to these, and may photograph and measure the work position of an electric wire other than a twisted shielded pair electric wire or any other component other than an electric wire as a work. Furthermore, with regard to workpiece position measurement, the specific content of the processing is not important as long as the processing is based on the image of the alignment portion in the captured image.

[0049] Furthermore, in the above-described first and second embodiments, as an example of an image inspection device, image inspection devices 1 and 2 equipped with a first illumination unit 14 that irradiates illumination light L11 from a ring illumination 142 onto a twisted shielded pair electric wire W1 as a workpiece and onto an alignment unit 13 are exemplified. However, the image inspection device is not limited to this, and the portion that illuminates the workpiece or the like may be, for example, a plurality of point illuminations other than a ring illumination, and the specific illumination mode is not important.

[0050] Furthermore, in the first and second embodiments described above, image inspection devices 1 and 2 provided with a second illumination unit 16 that irradiates background light are exemplified as an example of an image inspection device. However, the image inspection device is not limited to this, and may be one that does not have a second illumination unit and performs imaging without background light. However, as described above, by performing imaging under illumination with background light from the second illumination unit 16, the contours of the black images of the alignment units 13 and 23 in the captured images G11 and G12 can be made even clearer.

[0051] Furthermore, in the first and second embodiments described above, the alignment portions 13 and 23 have the inclined surfaces 131c and 231c that are convexly curved. However, the alignment portion is not limited to this, and the inclined surfaces of the alignment portions may be flat slopes extending from the edge of the side surface to the higher portion. However, as described above, by making the inclined surfaces 131c and 231c convexly curved, the outline of the black image of the alignment portions 13 and 23 in the captured images G11 and G12 can be made even clearer.

[0052] In the first embodiment, the alignment portion 13 is a pin member whose tip is a part of a spherical surface. In the second embodiment, the alignment portion 23 is a block member whose corners are rounded. However, the alignment portion is not limited to this, and any specific shape is acceptable as long as it has a side surface, a high portion, and an inclined surface. However, as described above, the alignment portion 13, in which the tip of the pin member is a part of a spherical surface, can be easily used as a reference for workpiece position measurement. Furthermore, as described above, the alignment portion 23, in which the corners of the block member are rounded, can further clarify the outline of the black image of the alignment portion 23 and reduce manufacturing costs by reducing the number of steps required to form the inclined surface. [Explanation of symbols]

[0053] 1. Image inspection equipment 11 Stand Frame 12 Workpiece holder 13,23 Alignment section 14 First Lighting Section (Lighting Section) 15 Photography Department 16 Second Lighting Section 17 Processing section 111 Base part 112 Support column part 121 Plate section 121a Rectangular window 122 Wire chuck part 122a First chuck 122b Second chuck 123 Alignment holder 131 Alignment body 131a,231a Side part 131a-1,231a-1 Edge 131b,231b High part 131c,231c Slope 131d center 131e,231e alignment line 132 Inset projection 141 Lighting retaining plate 141a Support part 141b Lighting fixed part 141c Photo window 142 Ring Light 151 Camera holder 152 Cameras 153 Camera Lens 231b-1 Edge 231d Corner apex 232 Rectangular groove D11 Length direction D12 Chuck direction D13 Axial direction D14 Shooting direction D21 Erecting direction G11, G12, G21, G22 captured images G11-1, G12-1, G21-1, G22-1 Reference lines L11 irradiation light L12 reflected light L121 Inclined surface reflected light L122 High-level reflected light T11,T21 distance W1 Twisted shielded pair wire (work) W1a Extension axis W11 Electric wire W12 Exposed conductor

Claims

1. an alignment unit for measuring the position of a workpiece, which is placed at a position where it will appear in the captured image together with the workpiece to be inspected; an illumination unit that irradiates illumination light onto the workpiece and the alignment unit; an imaging unit that captures images by receiving reflected light of the illumination light reflected by the workpiece and the alignment unit, The alignment unit includes: a side surface portion extending along the imaging direction of the imaging unit; a high-position portion that is captured in the captured image away from an edge of the side surface portion on the side of the imaging unit and is located closer to the imaging unit than the edge in the imaging direction; a surface portion extending at an angle from the edge to the high portion, the surface portion being an inclined surface that directs the reflected light in a direction different from the photographing unit side; An image inspection device comprising:

2. The image inspection device according to claim 1, further comprising a second illumination unit that is arranged on the opposite side of the photographing unit from the workpiece and the alignment unit and that irradiates background light onto the photographing unit through the workpiece and the alignment unit.

3. 2. The image inspection device according to claim 1, wherein the inclined surface is a convex curved surface that is convexly curved from the edge to the high portion.

4. 2. The image inspection device according to claim 1, wherein the alignment portion is a pin member arranged with its tip facing the imaging portion, and the high portion and the inclined surface are formed at the tip.

5. 5. The image inspection device according to claim 4, wherein the tip of the pin member is a part of a spherical surface with the apex thereof being the high-position portion.

6. The image inspection device according to claim 1, characterized in that the alignment section is a block member having a flat surface formed as the higher section on the imaging section side, and the inclined surface is formed from at least a portion of the periphery of the flat surface to the end edge.

7. The image inspection device according to claim 6, wherein the block member is a rectangular block having a rounded edge on the corner edge on the side of the imaging unit, the portion higher than the chamfered portion being the flat surface, and the chamfered portion being the inclined surface.

Images