Inspection device

Abstract

To provide an inspection device for inspecting presence / absence of defects on a surface of an inspected object having translucency.SOLUTION: An inspection device 1 includes: an illumination unit 21 that includes one surface 60S1 curved in a convex shape and the other surface 60S2 that opposes the one surface 60S1 and is curved in a recessed shape, is disposed in a side of the other surface 60S2 on the basis of an inspected object 60 that has translucency and is used for a lighting fixture, and applies light to the other surface 60S2; an imaging unit 30 that is disposed in the side of one surface 60S1 on the basis of the inspected object 60 and images light from the illumination unit 21 that is transmitted through the inspected object 60; an inspection section 40 for determining presence / absence of defects on one surface 60S1 and the other surface 60S2 of the inspected object 60 on the basis of the image captured by the imaging unit 30; and a transparent support film 13 that crosses between the illumination unit 21 and the imaging unit 31 and conveys the inspected object 60.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an inspection apparatus for inspecting the surface of a light-transmitting object for defects. [Background technology]

[0002] In an inspection device that inspects the surface of a translucent object for defects, various configurations have been considered to improve the accuracy of defect detection. For example, the following Patent Document 1 discloses an inspection device that includes an illumination unit that irradiates a translucent object with light, and an imaging unit that faces the illumination unit across the object for inspection and captures the light from the illumination unit that passes through the object for inspection. In this inspection device, the presence or absence of a defect on the surface of the object for inspection is determined based on an image captured by the imaging unit.

[0003] [Patent Document 1] JP 2009-180601 A Summary of the Invention

[0004] For example, the inspection device described in the above-mentioned Patent Document 1 may be used to inspect the surface of an outer cover of a lamp through which light passes for defects such as foreign matter. In general, the outer cover includes a convexly curved front surface and a concavely curved rear surface facing the front surface. In addition, the outer cover may have a rib protruding from the rear surface on the outer periphery, and the rib may be attached to another component of the lamp, for example.

[0005] An inspection device according to a first aspect of the present invention is characterized in that it comprises: an illumination unit arranged on the other surface side of an inspection object having translucency, the inspection object including one surface that is convexly curved and another surface that is opposite to the one surface and is concavely curved, and irradiates light onto the other surface; an imaging unit arranged on the one surface side of the inspection object, the inspection object being inspected, and imaging light from the illumination unit that passes through the inspection object; and an inspection section that determines the presence or absence of defects on the one surface and the other surface of the inspection object based on an image captured by the imaging unit.

[0006] In the inspection device of the first aspect, the illumination unit irradiates light onto the other surface that is curved concavely. For this reason, for example, when a rib protruding from the other surface is provided on the outer periphery of the object to be inspected, the light from the illumination unit may be reflected by the boundary between the rib and the other surface or by the rib, etc., and proceed toward the other surface. In this way, a part of the light proceeding toward the other surface is reflected by the other surface. In the inspection device of the first aspect, as described above, the imaging unit is disposed on one surface side with the object to be inspected as a reference, so that the light reflected by the other surface is prevented from entering the imaging unit. In addition, the other part of the light proceeding toward the other surface enters the object to be inspected from the other surface and exits from the one surface. In the inspection device of the first aspect, as described above, the one surface is curved convexly, so that the light entering the object to be inspected from the other surface can be diffused and emitted from the one surface, and this light is prevented from entering the imaging unit. Therefore, the light from the illumination unit is unlikely to be reflected by the boundary between the rib and the other surface, the rib, etc., and this reflected light is unlikely to be captured in the image captured by the imaging unit. Therefore, the inspection device of the first aspect can suppress a decrease in the detection accuracy of defects on the surface of the object to be inspected, even if the outer periphery of the object to be inspected has a rib protruding from the other surface.

[0007] In addition, in the inspection device of the first aspect, the illumination unit may have a first illumination section that irradiates light onto the other surface of the object to be inspected from a first direction, and a second illumination section that irradiates light onto the other surface of the object to be inspected from a second direction different from the first direction, and the imaging unit may be configured to individually image the light from the first illumination section and the light from the second illumination section that pass through the object to be inspected.

[0008] In the inspection device of the first aspect, the inspection unit judges the presence or absence of a defect based on an image captured by light from a first illumination unit irradiated onto the other side of the object to be inspected from a first direction and passing through the object to be inspected. Furthermore, the inspection unit judges the presence or absence of a defect based on an image captured by light from a second illumination unit irradiated onto the other side of the object to be inspected from a second direction different from the first direction and passing through the object to be inspected. That is, the inspection unit judges the presence or absence of a defect in each of the cases where the first illumination unit irradiates the other side of the object to be inspected with light from the first direction and where the second illumination unit irradiates the other side of the object to be inspected with light from the second direction different from the first direction. Since the first direction and the second direction are different from each other, absorption, reflection, refraction, etc. of light caused by defects in the object to be inspected when light is irradiated from the first direction differs from when light is irradiated from the second direction. Therefore, a defect that was difficult to show in an image when light is irradiated from the first direction may be easily shown in an image when light is irradiated from the second direction, and a defect that was difficult to show in an image when light is irradiated from the second direction may be easily shown in an image when light is irradiated from the second direction. Therefore, the inspection device of the first aspect can suppress a decrease in the detection accuracy of defects in the inspected object compared to a case in which the illumination unit does not have the second illumination unit.

[0009] In addition, in the inspection device of the first aspect, when the lighting unit has a first lighting section and a second lighting section, the time when the first lighting section irradiates light onto the other side of the object to be inspected and the time when the second lighting section irradiates light onto the other side of the object to be inspected may be different from each other.

[0010] With this configuration, the light from the second illumination unit is not reflected in an image captured using the light from the first illumination unit. Also, the light from the first illumination unit is not reflected in an image captured using the light from the second illumination unit. Therefore, even if the imaging unit does not have, for example, a first imaging unit that captures the light from the first illumination unit and a second imaging unit that captures the light from the second illumination unit, the imaging unit can capture the light from the first illumination unit and the light from the second illumination unit separately.

[0011] In addition, in the inspection device of the first aspect, when the lighting unit has a first lighting section and a second lighting section, the imaging unit intersects with a first line that is parallel to the optical axis of the first lighting section and passes through the light exit surface of the first lighting section, and does not intersect with a second line that is parallel to the optical axis of the second lighting section and passes through the light exit surface of the second lighting section, and the inspection section may determine the absence or presence of the defect from dark areas in an image captured with light from the first lighting section, and determine the presence or absence of the defect from bright areas in an image captured with light from the second lighting section.

[0012] When the object to be inspected has a defect, most of the light incident on the defect among the light irradiated on the object to be inspected is absorbed or reflected by the defect. On the other hand, most of the light not incident on the defect passes through the object to be inspected. In the inspection device of the first aspect, as described above, the imaging unit is parallel to the optical axis of the first illumination unit and intersects with the first straight line passing through the light exit surface of the first illumination unit, so that the imaging unit can image the light from the first illumination unit that does not enter the defect and passes through the object to be inspected. Therefore, the defect can be displayed as a dark area in the image in which the light from the first illumination unit is imaged. In addition, in the inspection device of the first aspect, as described above, the imaging unit is parallel to the optical axis of the second illumination unit and does not intersect with the second straight line passing through the light exit surface of the second illumination unit, so that the imaging unit can image the light from the second illumination unit that enters the defect and is reflected by the defect, while not imaging the light that does not enter the defect and passes through the object to be inspected. Therefore, the defect can be displayed as a bright area in the image in which the light from the second illumination unit is imaged. However, since light propagates while diffusing, if the defect is thin and fibrous, such as hair or lint, such a defect tends not to be shown as a dark area in an image captured with the light from the first illumination unit. However, in the inspection device of the first aspect, such a defect can be shown as a bright area in an image captured with the light from the second illumination unit. Therefore, the inspection device of the first aspect can detect even thin defects such as fibrous foreign matter.

[0013] Alternatively, when the lighting unit has a first lighting section and a second lighting section, the imaging unit has a first imaging section that images the light from the first lighting section that passes through the inspection object, and a second imaging section that images the light from the second lighting section that passes through the inspection object, wherein the first imaging section intersects with a first line that is parallel to the optical axis of the first illumination section and passes through the light exit surface of the first illumination section, and the second imaging section does not intersect with a second line that is parallel to the optical axis of the second illumination section and passes through the light exit surface of the second illumination section, and the inspection section may determine the presence or absence of the defect from dark areas in the image captured by the first imaging section, and determine the presence or absence of the defect from bright areas in the image captured by the second imaging section.

[0014] In the inspection device of the first aspect, as described above, the first imaging unit intersects with a first straight line that is parallel to the optical axis of the first illumination unit and passes through the light exit surface of the first illumination unit. Therefore, as described above, the defect can be displayed as a dark area in an image captured by the first imaging unit using light from the first illumination unit. Also, as described above, the second imaging unit does not intersect with a second straight line that is parallel to the optical axis of the second illumination unit and passes through the light exit surface of the second illumination unit. Therefore, as described above, the defect can be displayed as a bright area in an image captured by the second imaging unit using light from the second illumination unit. Therefore, even with an inspection device configured in this way, fine defects such as fibrous foreign matter can be detected.

[0015] In addition, in the inspection device of the first aspect, when the imaging unit intersects with the first straight line but does not intersect with the second straight line, and when the imaging unit has a first imaging unit and a second imaging unit, the light from the second illumination unit may be collimated light or light that is focused on the other surface of the object to be inspected.

[0016] By using this configuration, the brightness of the bright area when the defect is displayed as a bright area can be increased compared to when the light from the second illumination unit is diffused light, and the accuracy of detecting thin defects such as fibrous foreign matter can be increased.

[0017] In addition, in the inspection device of the first aspect, the imaging unit has a first imaging section that images light from the lighting unit that is parallel to the optical axis of the lighting unit, intersects with a straight line passing through the light exit surface of the lighting unit, and passes through the inspected object, and a second imaging section that images light from the lighting unit that does not intersect with the straight line and passes through the inspected object, and the inspection section may determine the presence or absence of the defect from dark areas in the image captured by the first imaging section, and determine the presence or absence of the defect from bright areas in the image captured by the second imaging section.

[0018] In the inspection device of the first aspect, as described above, the first imaging unit intersects with a line that is parallel to the optical axis of the lighting unit and passes through the light exit surface of the lighting unit. Therefore, as described above, the defect can be displayed as a dark area in the image captured by the first imaging unit of the light from the lighting unit. Also, as described above, the second imaging unit does not intersect with a line that is parallel to the optical axis of the lighting unit and passes through the light exit surface of the lighting unit. Therefore, as described above, the defect can be displayed as a bright area in the image captured by the second imaging unit of the light from the lighting unit. Therefore, even with an inspection device configured in this way, it is possible to detect fine defects such as fibrous foreign matter.

[0019] An inspection device according to a second aspect of the present invention is characterized in that it comprises: an illumination unit arranged on the one side of an inspection object having translucency, the inspection object including one side that is convexly curved and another side that is opposite to the one side and curved concavely, and irradiating light onto the one side; an imaging unit arranged on the other side of the inspection object, the inspection object being imaged by light from the illumination unit that passes through the inspection object; and an inspection section that determines the presence or absence of defects on the one side and the other side of the inspection object based on an image captured by the imaging unit.

[0020] For example, when a rib protruding from the other surface is provided on the outer periphery of the object to be inspected, light passing through the rib or light reflected by the rib may be reflected in the image captured by the imaging unit. When such a rib is provided, and the illumination unit is disposed on the other surface side of the object to be inspected as a reference, and the imaging unit is disposed on the one surface side of the object to be inspected as a reference, the light from the illumination unit that travels from the rib toward the imaging unit is likely to travel toward the imaging unit via the other surface or one surface in the vicinity of the rib. In this case, most of the light traveling from the rib toward the imaging unit is likely to overlap with the light traveling toward the imaging unit via the other surface or one surface in the vicinity of the rib without passing through the rib and enter the imaging unit. In other words, in the image captured by the imaging unit, the light from the rib is likely to overlap with the other surface or one surface in the vicinity of the rib. For this reason, the light traveling from the rib toward the imaging unit tends to make it difficult to properly detect defects on the other surface or one surface in the vicinity of the rib. On the other hand, in the inspection device according to the second aspect, as described above, the illumination unit is disposed on one side of the object to be inspected as a reference, and the imaging unit is disposed on the other side of the object to be inspected as a reference. Therefore, when a rib protruding from the other side is provided on the outer periphery of the object to be inspected as described above, a part of the light from the illumination unit that enters the object to be inspected from one side, or a part of the light that enters the object to be inspected from one side and exits from the other side of the object to be inspected, may enter the rib or be reflected by the rib and head toward the imaging unit. Even if light heads toward the imaging unit from the rib in this way, the light is likely to head toward the imaging unit without passing through the other side or one side in the vicinity of the rib. Therefore, compared to a case in which the lighting unit is positioned on the other side of the object to be inspected and the imaging unit is positioned on one side of the object to be inspected, even if light is directed from the rib toward the imaging unit, the light is less likely to overlap with light that is directed toward the imaging unit via the other side or one side near the rib without passing through the rib, which can prevent defects on the other side or one side near the rib from being unable to be properly detected.Therefore, this inspection device according to the second aspect can prevent the inspection range for defects on the surface of the object from being narrowed, even if a rib protruding from the other side is provided on the outer peripheral edge of the object to be inspected and light is directed from the rib toward the imaging unit.

[0021] In addition, in a second aspect of the inspection device, the illumination unit may have a first illumination section that irradiates light onto the one surface of the object to be inspected from a first direction, and a second illumination section that irradiates light onto the one surface of the object to be inspected from a second direction different from the first direction, and the imaging unit may be configured to individually image the light from the first illumination section and the light from the second illumination section that pass through the object to be inspected.

[0022] In the inspection device according to the second aspect, the inspection unit judges the presence or absence of a defect based on an image captured by light from a first illumination unit that is irradiated onto one side of the object to be inspected from a first direction and passes through the object to be inspected. Furthermore, the inspection unit judges the presence or absence of a defect based on an image captured by light from a second illumination unit that is irradiated onto one side of the object to be inspected from a second direction different from the first direction and passes through the object to be inspected. That is, the inspection unit judges the presence or absence of a defect in each of the cases where the first illumination unit irradiates the one side of the object to be inspected with light from the first direction and where the second illumination unit irradiates the one side of the object to be inspected with light from the second direction different from the first direction. Since the first direction and the second direction are different from each other, absorption, reflection, refraction, etc. of light caused by defects in the object to be inspected when light is irradiated from the first direction differs from when light is irradiated from the second direction. Therefore, a defect that was difficult to show in an image when light is irradiated from the first direction may be easily shown in an image when light is irradiated from the second direction, and a defect that was difficult to show in an image when light is irradiated from the second direction may be easily shown in an image when light is irradiated from the second direction. Therefore, the inspection device according to the second aspect can suppress a decrease in the detection accuracy of defects in the inspected object compared to a case in which the illumination unit does not have the second illumination unit.

[0023] In addition, in the inspection device of the second aspect, when the lighting unit has a first lighting section and a second lighting section, the time when the first lighting section irradiates light onto the one side of the object to be inspected and the time when the second lighting section irradiates light onto the one side of the object to be inspected may be different from each other.

[0024] With this configuration, the light from the second illumination unit is not reflected in an image captured using the light from the first illumination unit. Also, the light from the first illumination unit is not reflected in an image captured using the light from the second illumination unit. Therefore, even if the imaging unit does not have, for example, a first imaging unit that captures the light from the first illumination unit and a second imaging unit that captures the light from the second illumination unit, the imaging unit can capture the light from the first illumination unit and the light from the second illumination unit separately.

[0025] In addition, in the inspection device of the second aspect, when the lighting unit has a first lighting section and a second lighting section, the imaging unit intersects with a first line that is parallel to the optical axis of the first lighting section and passes through the light exit surface of the first lighting section, and does not intersect with a second line that is parallel to the optical axis of the second lighting section and passes through the light exit surface of the second lighting section, and the inspection section may determine the absence or presence of the defect from dark areas in an image captured with light from the first lighting section, and determine the presence or absence of the defect from bright areas in an image captured with light from the second lighting section.

[0026] When the object to be inspected has a defect, most of the light incident on the defect among the light irradiated on the object to be inspected is absorbed or reflected by the defect. On the other hand, most of the light not incident on the defect passes through the object to be inspected. In the inspection device according to the second aspect, as described above, the imaging unit is parallel to the optical axis of the first illumination unit and intersects with the first straight line passing through the light exit surface of the first illumination unit, so that the imaging unit can image the light from the first illumination unit that does not enter the defect and passes through the object to be inspected. Therefore, the defect can be displayed as a dark area in the image in which the light from the first illumination unit is imaged. In addition, in the inspection device according to the second aspect, as described above, the imaging unit is parallel to the optical axis of the second illumination unit and does not intersect with the second straight line passing through the light exit surface of the second illumination unit, so that the imaging unit can image the light from the second illumination unit that enters the defect and is reflected by the defect, while not imaging the light that does not enter the defect and passes through the object to be inspected. Therefore, the defect can be displayed as a bright area in the image in which the light from the second illumination unit is imaged. However, since light propagates while diffusing, if the defect is thin and fibrous, such as a hair or lint, such a defect tends not to be shown as a dark area in an image captured with the light from the first illumination unit. However, in the inspection device according to the second aspect, such a defect can be shown as a bright area in an image captured with the light from the second illumination unit. Therefore, this inspection device can detect even thin defects such as fibrous foreign matter.

[0027] Alternatively, when the lighting unit has a first lighting section and a second lighting section, the imaging unit has a first imaging section that images the light from the first lighting section that passes through the inspection object, and a second imaging section that images the light from the second lighting section that passes through the inspection object, wherein the first imaging section intersects with a first line that is parallel to the optical axis of the first illumination section and passes through the light exit surface of the first illumination section, and the second imaging section does not intersect with a second line that is parallel to the optical axis of the second illumination section and passes through the light exit surface of the second illumination section, and the inspection section may determine the presence or absence of the defect from dark areas in the image captured by the first imaging section, and determine the presence or absence of the defect from bright areas in the image captured by the second imaging section.

[0028] In the inspection device according to the second aspect, as described above, the first imaging unit intersects with a first straight line that is parallel to the optical axis of the first illumination unit and passes through the light exit surface of the first illumination unit. Therefore, as described above, the defect can be displayed as a dark area in an image captured by the first imaging unit using light from the first illumination unit. Also, as described above, the second imaging unit does not intersect with a second straight line that is parallel to the optical axis of the second illumination unit and passes through the light exit surface of the second illumination unit. Therefore, as described above, the defect can be displayed as a bright area in an image captured by the second imaging unit using light from the second illumination unit. Therefore, even with an inspection device configured in this way, fine defects such as fibrous foreign matter can be detected.

[0029] In addition, in the second aspect of the inspection device, when the imaging unit intersects with the first straight line but does not intersect with the second straight line, and when the imaging unit has a first imaging unit and a second imaging unit, the light from the second illumination unit may be collimated light or light that is focused on the other surface of the object to be inspected.

[0030] By using this configuration, the brightness of the bright area when the defect is displayed as a bright area can be increased compared to when the light from the second illumination unit is diffused light, and the accuracy of detecting thin defects such as fibrous foreign matter can be increased.

[0031] In addition, in the inspection device of the second aspect, the imaging unit has a first imaging section that images light from the lighting unit that is parallel to the optical axis of the lighting unit, intersects with a straight line passing through the light exit surface of the lighting unit, and passes through the inspected object, and a second imaging section that images light from the lighting unit that does not intersect with the straight line and passes through the inspected object, and the inspection section may determine the presence or absence of the defect from dark areas in the image captured by the first imaging section, and determine the presence or absence of the defect from bright areas in the image captured by the second imaging section.

[0032] In the inspection device according to the second aspect, as described above, the first imaging unit intersects with a line that is parallel to the optical axis of the lighting unit and passes through the light exit surface of the lighting unit. Therefore, as described above, the defect can be displayed as a dark area in an image captured by the first imaging unit using the light from the lighting unit. Also, as described above, the second imaging unit does not intersect with a line that is parallel to the optical axis of the lighting unit and passes through the light exit surface of the lighting unit. Therefore, as described above, the defect can be displayed as a bright area in an image captured by the second imaging unit using the light from the lighting unit. Therefore, even an inspection device configured in this way can detect fine defects such as fibrous foreign matter.

[0033] In addition, the above-mentioned inspection device of the second aspect may further include another lighting unit arranged on the other surface side of the object to be inspected as a reference and irradiating light onto the other surface, and another imaging unit arranged on the one surface side of the object to be inspected as a reference and imaging light from the other lighting unit that passes through the object to be inspected, and the inspection section may determine the presence or absence of defects on the one surface and the other surface of the object to be inspected based on an image captured by the imaging unit and an image captured by the other imaging unit. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 is a diagram illustrating an inspection device according to a first embodiment of a first aspect of the present invention. [Diagram 2] 2 is a view of the inspection device in FIG. 1 as seen from the downstream side in the first transport direction. [Diagram 3] FIG. 2 is a diagram illustrating a part of an example of an image captured by an imaging unit. [Figure 4] FIG. 2 is a diagram for explaining propagation of light from a lighting unit. [Diagram 5] FIG. 2 is a view similar to FIG. 1 showing an inspection device according to a second embodiment as a first aspect of the present invention. [Figure 6] 11 is a diagram illustrating a part of an example of an image of light from a second illumination section captured by an imaging unit. FIG. [Figure 7] FIG. 2 is a view similar to FIG. 1 showing an inspection device according to a third embodiment as the first aspect of the present invention. [Figure 8] FIG. 2 is a diagram similar to FIG. 1 showing an inspection device according to a fourth embodiment as a first aspect of the present invention. [Figure 9] FIG. 13 is a diagram illustrating an inspection device according to a fifth embodiment as a second aspect of the present invention. [Figure 10] 10 is a diagram of the inspection device in FIG. 9 as viewed from the downstream side in the first transport direction. [Figure 11] FIG. 10 is a diagram similar to FIG. 9 showing an inspection device according to a sixth embodiment as a second aspect of the present invention. [Figure 12] FIG. 10 is a diagram similar to FIG. 9 showing an inspection device according to a seventh embodiment as a second aspect of the present invention. [Figure 13] FIG. 10 is a diagram similar to FIG. 9 showing an inspection device according to an eighth embodiment as a second aspect of the present invention. [Figure 14] FIG. 10 is a diagram similar to FIG. 9 showing an inspection device according to a ninth embodiment as a second aspect of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Hereinafter, embodiments for carrying out the inspection device according to the present invention will be illustrated with reference to the accompanying drawings. The embodiments illustrated below are intended to facilitate understanding of the present invention, and are not intended to limit the present invention. The present invention can be modified or improved from the following embodiments without departing from the spirit of the present invention. In the drawings referred to below, the dimensions of each component may be changed or reference symbols may be omitted in order to facilitate understanding.

[0036] (First embodiment) A first embodiment as a first aspect of the present invention will be described. FIG. 1 is a diagram showing an inspection device in this embodiment. As shown in FIG. 1, the inspection device 1 of this embodiment mainly comprises a conveying device 10, a lighting unit 21, an imaging unit 30, an inspection section 40, a display section 50, and a control section CO. An inspection object 60 inspected by the inspection device 1 in this embodiment is an outer cover that transmits light in a vehicle lamp. The inspection device 1 inspects the surface of the inspection object 60 for defects, for example, the presence or absence of foreign matter attached to the surface. For ease of understanding, the inspection object 60 is shown by a vertical cross section in FIG. 1.

[0037] The inspection object 60 of this embodiment, which is an outer cover, is a plate-like member having translucency and curved in a convex shape toward one surface 60S1. A translucent rib 61 protruding toward the other surface 60S2 is provided on the outer periphery of the inspection object 60, and the rib 61 extends around the entire circumference of the outer periphery of the inspection object 60. The inspection object 60 includes a hard coat layer (not shown) provided on the one surface 60S1 and an anti-fogging coat layer (not shown) provided on the other surface 60S2. The outer surface of the hard coat layer is the one surface 60S1 of the inspection object 60, and the outer surface of the anti-fogging coat layer is the other surface 60S2 of the inspection object 60. For example, when forming the hard coat layer or the anti-fogging coat layer, foreign matter such as dust may adhere to these layers, causing defects on the surface of the inspection object 60. Such an inspection object 60 can be understood to have a light-transmitting, convexly curved surface 60S1 and a concavely curved surface 60S2 opposite to the surface 60S1. The inspection device 1 of this embodiment inspects the surface 60S1 and the surface 60S2 of the inspection object 60 for defects.

[0038] The control unit CO is composed of, for example, an integrated circuit such as a microcontroller, an integrated circuit (IC), a large-scale integrated circuit (LSI), or an application specific integrated circuit (ASIC), or an NC (Numerical Control) device. When an NC device is used, the control unit CO may or may not use a machine learning device. As described below, some components of the inspection device 1 are controlled by the control unit CO.

[0039] The conveying device 10 is a device that conveys the object 60 to be inspected in a predetermined direction. The conveying device 10 of this embodiment includes a roller 11, a roller 12, and a transparent, strip-shaped support film 13. The rollers 11 and 12 are arranged at a predetermined interval in a roughly horizontal direction. One end of the support film 13 is wound around one roller 11, and the other end of the support film 13 is wound around the other roller 12, and a predetermined tension is applied to the support film 13 between the rollers 11 and 12. The object 60 to be inspected is placed on the support film 13 between the rollers 11 and 12 so as to be located closer to the roller 11 than the illumination unit 21 and the imaging unit 30 described later. In this embodiment, the object 60 to be inspected is placed so that the end of the rib 61 of the object 60 is in contact with the support film 13, and one surface 60S1 of the object 60 to be inspected is located on the opposite side to the support film 13 side from the other surface 60S2 in the vertical direction. By the rotation of the rollers 11 and 12, the inspection object 60 placed on the support film 13 is transported in a substantially horizontal direction from one roller 11 side to the other roller 12 side, which is the first transport direction D1. The rollers 11 and 12 adjust the rotation speed and rotation direction by a control signal from the control unit CO. Therefore, the transport device 10 can transport the inspection object 60 in a second transport direction D2, which is the opposite direction to the first transport direction D1, by reversing the rotation direction of the rollers 11 and 12. An example of the support film 13 is a resin film. Note that the transport device 10 is not particularly limited in configuration as long as it can transport the inspection object 60 in a predetermined direction. For example, the transport device 10 may be composed of a light-transmitting jig that supports the inspection object 60 and a transport mechanism that transports the jig. In this case, the transport mechanism may be configured to include two linear actuators that are arranged to extend substantially parallel to one side and the other side of the jig. The transport mechanism may be a robot arm, in which case the robot arm may support the object 60 to be inspected.

[0040] The lighting unit 21 of this embodiment is disposed below the support film 13 between the rollers 11 and 12. The lighting unit 21 irradiates the other surface 60S2 of the inspection object 60 transported by the transport device 10 with light L1 through the support film 13. That is, it can be understood that the lighting unit 21 is disposed on the other surface 60S2 side of the inspection object 60 as a reference and irradiates the other surface 60S2 with light L1. FIG. 2 is a view of the inspection device 1 of FIG. 1 as seen from the downstream side of the first transport direction D1. Note that, for ease of understanding, in FIG. 2, the inspection object 60 is shown in a vertical cross section. In addition, in FIG. 2, the light L1 emitted from the lighting unit 21 is shown by a two-dot chain line. As shown in FIG. 2, the lighting unit 21 of this embodiment is a single line lighting device composed of a plurality of LEDs arranged in parallel in a direction substantially perpendicular and substantially horizontal to the first transport direction D1. As shown in FIG. 1, a straight line 21a that is parallel to the optical axis of the illumination unit 21 and passes through the light emission surface 21e of the illumination unit 21 is approximately parallel to the vertical, and the light L1 emitted from the illumination unit 21 is white. The straight line 21a may be non-parallel to the vertical direction. Since the inspection object 60 has translucency as described above, the light L1 emitted from the illumination unit 21 passes through the inspection object 60 from the other surface 60S2 side to the one surface 60S1 side of the inspection object 60. Since the illumination unit 21 is a line illumination as described above, the portion of the inspection object 60 through which the light L1 from the illumination unit 21 passes is a line extending in a direction approximately perpendicular to the first transport direction D1. The illumination unit 21 switches between emitting and not emitting light according to a control signal from the control unit CO.

[0041] The imaging unit 30 of this embodiment is disposed above the object 60 to capture the light L1 from the illumination unit 21 that passes through the object 60. That is, the imaging unit 30 is disposed on one surface 60S1 side of the object 60 to capture the light L1 from the illumination unit 21 that passes through the object 60. In this embodiment, the imaging unit 30 is a line sensor camera, is positioned approximately directly above the illumination unit 21, and intersects with the straight line 21a. The imaging unit 30 is disposed so that the imaging range extends in a direction approximately perpendicular to the first transport direction D1 and is located at a portion of the object 60 through which the light L1 from the illumination unit 21 passes or in the vicinity of the portion. The control unit CO controls the imaging unit 30 to capture the light that passes through the object 60 being transported to the imaging unit 30 at a predetermined time interval and to output a two-dimensional image including the entire one surface 60S1 of the object 60 to the inspection unit 40. Furthermore, the control unit CO controls the illumination unit 21 to cause the illumination unit 21 not to emit the light L1. The imaging unit 30 may output one-dimensional images captured at a predetermined time interval to the inspection unit 40. In this case, the inspection unit 40, which will be described later, generates a two-dimensional image including the entire one surface 60S1 from the multiple one-dimensional images input to the inspection unit 40.

[0042] The inspection section 40 of this embodiment judges the presence or absence of defects on one surface 60S1 and the other surface 60S2 of the inspection object 60 based on the two-dimensional image input from the imaging unit 30. The judgment by the inspection section 40 means changing the signal output from the inspection section 40 to the control section CO based on the two-dimensional image. Specific judgments by the inspection section 40 will be described later. An example of the configuration of such an inspection section 40 is a configuration similar to that of the control section CO.

[0043] The display unit 50 displays the inspection result based on the determination of the presence or absence of defects made by the inspection unit 40. An example of the display unit 50 is a liquid crystal display.

[0044] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0045] First, the object 60 to be inspected is placed on the support film 13 between the rollers 11 and 12 of the transport device 10 so as to be located closer to the rollers 11 than the illumination unit 21 and the imaging unit 30. The control unit CO controls the illumination unit 21 to emit light L1. The control unit CO also controls the transport device 10 to transport the object 60 to the first transport direction D1. For this reason, the illumination unit 21 irradiates the other surface 60S2 of the object 60 to be inspected, which is transported by the transport device 10 in the first transport direction D1, with light L1 through the support film 13. The control unit CO controls the imaging unit 30 to capture the light L1 from the illumination unit 21 that passes through the object 60 to be inspected, which is transported in the first transport direction D1, at a predetermined time interval, and outputs a two-dimensional image including the entire one surface 60S1 of the object 60 to the inspection section 40.

[0046] Here, when there is a defect such as a foreign object on one surface 60S1 or the other surface 60S2 of the inspection object 60, most of the light L1 irradiated to the inspection object 60 by the illumination unit 21 and incident on the defect is absorbed or reflected by the defect and does not enter the imaging unit 30. On the other hand, most of the light not incident on the defect passes through the inspection object 60 from the other surface 60S2 side to the one surface 60S1 side and enters the imaging unit 30. For this reason, as shown in FIG. 3, in the image of the light L1 from the illumination unit 21 captured by the imaging unit 30, the defect may be displayed as a dark portion 72 surrounded by a bright portion 71. FIG. 3 is a diagram showing a schematic view of a part of an example of an image captured by the imaging unit 30. In FIG. 3, the dark portion 72 is hatched.

[0047] The inspection section 40 of this embodiment extracts areas having a brightness value lower than a predetermined threshold value in an image captured by the imaging unit 30, and calculates the area of ​​the extracted areas. Then, when at least one of the calculated areas is larger than the predetermined area, the inspection section 40 outputs a signal indicating that there is a defect to the control section CO. On the other hand, when all of the calculated areas are smaller than the predetermined area or when no areas are extracted, the inspection section 40 outputs a signal indicating that there is no defect to the control section CO. In this way, the inspection section 40 judges the presence or absence of defects on one surface 60S1 and the other surface 60S2 of the inspection object 60 based on the image captured by the imaging unit 30. Note that it is sufficient for the inspection section 40 to be able to judge the presence or absence of defects on one surface 60S1 and the other surface 60S2 of the inspection object 60 based on the image captured by the imaging unit 30. For example, the inspection section 40 may perform a binarization process on the two-dimensional image input from the imaging unit 30 using a predetermined threshold value, and extract areas having a brightness value lower than the predetermined threshold value in the binarized image. In addition, the inspection unit 40 may calculate the area of ​​the extracted region and the maximum width of the region, and if the calculated area is larger than a predetermined area and the calculated width is larger than the predetermined width, output a signal to the control unit CO indicating that there is a defect.

[0048] The control unit CO outputs a control signal corresponding to a signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. In this way, the inspection device 1 of this embodiment inspects the presence or absence of defects on one surface 60S1 and the other surface 60S2 of the inspection object 60. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the second conveying direction D2, which is the opposite direction to the first conveying direction D1, and returns the inspection object 60 to the position where the inspection object 60 was placed on the conveying device 10. Therefore, the position of the inspection object 60 before inspection and the position of the inspection object 60 after inspection are approximately the same. Therefore, for example, an operator who places the inspection object 60 on the conveying device 10 of the inspection device 1 can store the inspection object 60 after inspection without moving. It is noted that the conveying device 10 does not need to convey such an inspection object 60 in the second conveying direction D2.

[0049] Meanwhile, the outer peripheral edge of the inspection object 60, which is the outer cover, is provided with a rib 61 that protrudes toward the other surface 60S2. For this reason, depending on the direction of irradiation of light onto the inspection object 60, the light may be reflected by the boundary between the rib 61 and the other surface 60S2 or by the rib 61, etc., and the reflected light may appear in an image. When reflected light is reflected in an image in this way, it may be impossible to detect a defect due to this light, or this light may be erroneously detected as a defect, which tends to reduce the accuracy of defect detection.

[0050] Therefore, the inspection device 1 of this embodiment includes an illumination unit 21, an imaging unit 30, and an inspection section 40. The illumination unit 21 is disposed on the other surface 60S2 side of the inspection object 60, which includes one surface 60S1 curved convexly and the other surface 60S2 curved concavely opposite to the one surface 60S1 and has translucency, and irradiates light L1 onto the other surface 60S2. The imaging unit 30 is disposed on the one surface 60S1 side of the inspection object 60, and images the light L1 from the illumination unit 21 that passes through the inspection object 60. The inspection section 40 judges the presence or absence of a defect in the inspection object 60 based on the image captured by the imaging unit 30. In the inspection device 1 of this embodiment, the illumination unit 21 irradiates light L1 onto the other surface 60S2 curved concavely. In addition, a rib 61 protruding from the other surface 60S2 is provided on the outer periphery of the inspection object 60. For this reason, as shown in Fig. 4, a part of the light L1 from the illumination unit 21 may be reflected by the boundary between the rib 61 and the other surface 60S2 or by the rib 61 and head toward the other surface 60S2. A part of the light L1a headed toward the other surface 60S2 is reflected by the other surface 60S2. In the inspection device 1 of this embodiment, the imaging unit 30 is disposed on the one surface 60S1 side with respect to the object to be inspected 60 as described above, so that the light reflected by the other surface 60S2 is prevented from entering the imaging unit 30. Another part of the light L1a headed toward the other surface 60S2 enters the object to be inspected 60 from the other surface 60S2 and exits from the one surface 60S1. In the inspection device 1 of this embodiment, since the one surface 60S1 is curved in a convex shape as described above, the light incident on the inspection object 60 from the other surface 60S2 can be diffused and emitted from the one surface 60S1, and the light is prevented from entering the imaging unit 30. Therefore, the light emitted from the illumination unit 21 and reflected from the boundary between the rib 61 and the other surface 60S2 or from the rib 61 is unlikely to be reflected in the image captured by the imaging unit 30. Therefore, the inspection device 1 of this embodiment can prevent a decrease in the detection accuracy of defects on the one surface 60S1 or the other surface 60S2, which are the surfaces of the inspection object 60, even if the rib 61 protruding from the other surface 60S2 is provided on the outer periphery of the inspection object 60.

[0051] Second embodiment Next, a second embodiment as the first aspect of the present invention will be described in detail with reference to Fig. 5. Note that components that are the same as or equivalent to those in the first embodiment will be given the same reference numerals and duplicated descriptions will be omitted unless otherwise specified.

[0052] Fig. 5 is a diagram showing an inspection device in a second embodiment of the present invention similar to Fig. 1. As shown in Fig. 5, the inspection device 1 of this embodiment is mainly different from the inspection device 1 of the first embodiment in that the illumination unit 21 has a first illumination section 23 and a second illumination section 25. In Fig. 5, light L3 emitted from the first illumination section 23 and light L5 emitted from the second illumination section 25 are indicated by two-dot chain lines.

[0053] The first illumination section 23 in this embodiment has the same configuration as the illumination unit 21 in the first embodiment. Therefore, the first illumination section 23 in this embodiment is disposed below the support film 13 between the rollers 11 and 12, and is a line illumination composed of a plurality of LEDs arranged in parallel in a direction substantially perpendicular and substantially horizontal to the first conveying direction D1. In addition, a first straight line 23a that is parallel to the optical axis of the first illumination section 23 and passes through the light emission surface 23e of the first illumination section 23 is substantially parallel to the vertical, and the imaging unit 30 intersects with this first straight line 23a. The first illumination section 23 irradiates the other surface 60S2 of the inspection object 60 conveyed by the conveying device 10 with light L3 through the support film 13, and this light L3 passes through the inspection object 60 from the other surface 60S2 side to the one surface 60S1 side of the inspection object 60. The portion of the inspection object 60 through which the light L3 from the first illumination unit 23 passes forms a line extending in a direction substantially perpendicular to the first transport direction D1.

[0054] On the other hand, the second illumination section 25 of this embodiment is disposed below the support film 13 between the rollers 11 and 12, closer to the roller 11 than the first illumination section 23. The second illumination section 25 is a line illumination consisting of a plurality of LEDs arranged in parallel in a direction substantially perpendicular and substantially horizontal to the first conveying direction D1, similar to the first illumination section 23. A second straight line 25a that is parallel to the optical axis of the second illumination section 25 and passes through the light emission surface 25e of the second illumination section 25 extends in the vertical direction, but is inclined upward toward the roller 12 and is not parallel to the first straight line 23a. This second straight line 25a passes between the imaging unit 30 and the roller 12, and does not intersect with the imaging unit 30. The second illumination section 25 irradiates the other surface 60S2 of the inspection object 60 transported by the transport device 10 with light L5 through the support film 13, and this light passes through the inspection object 60 from the other surface 60S2 side to the one surface 60S1 side of the inspection object 60. The portion of the inspection object 60 through which the light L5 from the second illumination section 25 passes is linear and extends in a direction substantially perpendicular to the first transport direction D1, and overlaps with the portion of the inspection object 60 through which the light L3 from the first illumination section 23 passes. The imaging range of the imaging unit 30 is located at a portion where the portion of the inspection object 60 through which the light L3 from the first illumination section 23 passes and the portion of the inspection object 60 through which the light L5 from the second illumination section 25 passes overlap, or in the vicinity of this overlapping portion. In other words, the first illumination section 23, the second illumination section 25, and the imaging unit 30 are arranged so that the imaging range of the imaging unit 30 is positioned in this way.

[0055] In addition, the illumination unit 21 does not emit light L5 from the second illumination section 25 when emitting light L3 from the first illumination section 23, and does not emit light L3 from the first illumination section 23 when emitting light L5 from the second illumination section 25. In other words, the time when the first illumination section 23 irradiates the other surface 60S2 of the object 60 with light L3 and the time when the second illumination section 25 irradiates the other surface 60S2 of the object 60 with light L5 are different from each other.

[0056] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0057] In this embodiment, similarly to the first embodiment, the inspection object 60 is placed on the support film 13 between the rollers 11 and 12 of the conveying device 10 so as to be located closer to the rollers 11 than the illumination unit 21 and the imaging unit 30. The control unit CO controls the first illumination unit 23 to emit light L3. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the first conveying direction D1. For this reason, the first illumination unit 23 irradiates light through the support film 13 to the other surface 60S2 of the inspection object 60 conveyed by the conveying device 10 in the first conveying direction D1. At this time, the light L5 from the second illumination unit 25 is not emitted. The control unit CO controls the imaging unit 30 to capture light L3 from the first illumination unit 23 that passes through the object to be inspected 60 being transported in the first transport direction D1 at a predetermined time interval, and outputs a two-dimensional image including the entirety of one side 60S1 of the object to be inspected 60 to the inspection unit 40.

[0058] In this embodiment, after the imaging unit 30 has completed the imaging, the control unit CO controls the second illumination unit 25 to emit light L5. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the second conveying direction D2, and returns the inspection object 60 to the position where the inspection object 60 was placed on the conveying device 10. For this reason, the second illumination unit 25 irradiates the other surface 60S2 of the inspection object 60 conveyed in the second conveying direction D2 by the conveying device 10 with light L5 through the support film 13. At this time, the light L3 from the first illumination unit 23 is not emitted. The control unit CO controls the imaging unit 30 to capture light L5 from the second illumination unit 25 that passes through the object to be inspected 60 being transported in the second transport direction D2 at a predetermined time interval, and outputs a two-dimensional image including the entirety of one side 60S1 of the object to be inspected 60 to the inspection unit 40.

[0059] As described above, in this embodiment, the first straight line 23a and the second straight line 25a are non-parallel to each other. Therefore, it can be understood that the illumination unit 21 has the first illumination section 23 that irradiates the other surface 60S2 of the object 60 with light from a first direction, and the second illumination section 25 that irradiates the other surface 60S2 of the object 60 with light L5 from a second direction different from the first direction. In addition, it can be understood that the imaging unit 30 individually images the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 that pass through the object 60.

[0060] The inspection unit 40 of this embodiment judges the presence or absence of a defect based on an image captured by the light L3 from the first illumination unit 23, and further judges the presence or absence of a defect based on an image captured by the light L5 from the second illumination unit 25. Specifically, the inspection unit 40 judges the presence or absence of a defect from a dark area in an image captured by the light L3 from the first illumination unit 23. The first straight line 23a of this embodiment intersects with the imaging unit 30. Therefore, similar to the first embodiment, a defect may be displayed as a dark area in the image captured by the imaging unit 30 of the light L3 from the first illumination unit 23. Similarly to the first embodiment, the inspection unit 40 of this embodiment extracts an area having a luminance value lower than a predetermined threshold in the image captured by the imaging unit 30 of the light L3 from the first illumination unit 23, and calculates the area of ​​the extracted area. Then, if the calculated area is larger than the predetermined area, a signal indicating the presence of a defect is output to the control unit CO.

[0061] On the other hand, the second straight line 25a does not intersect with the imaging unit 30. Therefore, compared to the case where the second straight line 25a intersects with the imaging unit 30, among the light L5 irradiated to the inspection object 60 by the second illumination section 25, the light that does not enter the defects on the one surface 60S1 and the other surface 60S2 of the inspection object 60 and transmits through the inspection object 60 from the other surface 60S2 side to the one surface 60S1 side is less likely to enter the imaging unit 30. In this embodiment, the position and orientation of the second illumination section 25 with respect to the imaging unit 30 are adjusted so that among the light L5 irradiated to the inspection object 60 by the second illumination section 25, most of the light that transmits through the inspection object 60 in this way does not enter the imaging unit 30. On the other hand, among the light L5 irradiated to the inspection object 60 by the second illumination section 25, most of the light that enters the defects is absorbed by the defects or reflected by the defects. Therefore, the light that is reflected by the defects and transmits through the inspection object 60 can enter the imaging unit 30. Therefore, as shown in Fig. 6, in the image of the light L5 from the second illumination section 25 captured by the imaging unit 30, the defect may be displayed as a bright area 71 surrounded by a dark area 72. Note that Fig. 6 is a diagram that shows a part of an example of the image of the light L5 from the second illumination section 25 captured by the imaging unit 30. In Fig. 6, the dark area 72 is hatched. The inspection section 40 of this embodiment extracts areas having a luminance value higher than a predetermined threshold in the image of the light L5 from the second illumination section 25 captured by the imaging unit 30, and calculates the area of ​​the extracted area. Then, when at least one of the calculated areas is larger than the predetermined area, a signal indicating the presence of a defect is output to the control unit CO.

[0062] In addition, when all of the areas of the regions extracted in the image of the light L3 from the first illumination unit 23 captured by the imaging unit 30 are smaller than a predetermined area or no region is extracted, and when all of the areas of the regions extracted in the image of the light L5 from the second illumination unit 25 captured by the imaging unit 30 are larger than a predetermined area or no region is extracted, the inspection unit 40 outputs a signal indicating that there is no defect to the control unit CO. In this way, the inspection unit 40 determines the presence or absence of a defect based on an image captured by the light L3 from the first illumination unit 23, and further determines the presence or absence of a defect based on an image captured by the light L5 from the second illumination unit 25. In addition, it is sufficient for the inspection unit 40 to determine the presence or absence of a defect based on an image captured by the light L3 from the first illumination unit 23, and further determine the presence or absence of a defect based on an image captured by the light L5 from the second illumination unit 25. For example, when the inspection section 40 determines the presence or absence of a defect based on an image captured with the light L5 from the second illumination section 25, the inspection section 40 may perform binarization processing on the two-dimensional image input from the imaging unit 30 using a predetermined threshold, and extract an area having a luminance value higher than the predetermined threshold in the binarized image. Furthermore, when the inspection section 40 determines the presence or absence of a defect based on an image captured with the light L5 from the second illumination section 25, the inspection section 40 may calculate the area of ​​the extracted area and the maximum width of the area, and output a signal indicating the presence of a defect to the control section CO if the calculated area is larger than the predetermined area and the calculated width is larger than the predetermined width.

[0063] The control unit CO outputs a control signal corresponding to the signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. As described above, the object 60 to be inspected is returned to the position where the object 60 was placed on the transport device 10. Therefore, similar to the first embodiment, the position of the object 60 before inspection and the position of the object 60 after inspection are approximately the same.

[0064] As described above, in the inspection device 1 of this embodiment, the illumination unit 21 has the first illumination section 23 that irradiates the other surface 60S2 of the inspection object 60 with light L3 from a first direction, and the second illumination section 25 that irradiates the other surface 60S2 of the inspection object 60 with light L5 from a second direction different from the first direction. The imaging unit 30 individually captures the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 that pass through the inspection object 60. In addition, the imaging unit 30 intersects with the first straight line 23a but does not intersect with the second straight line 25a. In addition, the inspection section 40 judges the presence or absence of a defect from the dark portion 72 in the image captured with the light L3 from the first illumination section 23, and judges the presence or absence of a defect from the bright portion 71 in the image captured with the light L5 from the second illumination section 25. Incidentally, since light propagates while diffusing, if the defect is thin and fibrous, such as a hair or lint, such a defect tends not to be shown as a dark area 72 in an image captured with light L3 from the first illumination unit 23. However, the inspection device 1 of this embodiment can make such a defect appear as a bright area 71 in an image captured with light L5 from the second illumination unit 25. Therefore, the inspection device 1 of this embodiment can detect even thin defects such as fibrous foreign matter.

[0065] In the inspection device 1 of the present embodiment, the time when the first illumination section 23 irradiates the other surface 60S2 of the inspection object 60 with the light L3 is different from the time when the second illumination section 25 irradiates the other surface 60S2 of the inspection object 60 with the light L5. Therefore, the light L5 from the second illumination section 25 is not reflected in an image in which the light L3 from the first illumination section 23 is captured. Furthermore, the light L3 from the first illumination section 23 is not reflected in an image in which the light L5 from the second illumination section 25 is captured. Therefore, even if the imaging unit 30 does not have, for example, a first imaging section that captures the light L3 from the first illumination section 23 and a second imaging section that captures the light L5 from the second illumination section 25, the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 can be individually captured.

[0066] From the viewpoint of increasing the accuracy of detection of fine defects such as fibrous foreign matter, it is preferable that the light L5 from the second illumination unit 25 is collimated light or light that is focused on the other surface 60S2 of the inspection object 60. With this configuration, the brightness of the bright portion 71 when the defect is projected as the bright portion 71 can be increased compared to the case where the light L5 from the second illumination unit 25 is diffuse light, and the accuracy of detection of fine defects such as fibrous foreign matter can be increased.

[0067] Third embodiment Next, a third embodiment as the first aspect of the present invention will be described in detail with reference to Fig. 7. Note that components that are the same as or equivalent to those in the second embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0068] Fig. 7 is a diagram showing an inspection device in a third embodiment of the present invention in the same manner as Fig. 1. As shown in Fig. 7, the inspection device 1 in this embodiment differs from the inspection device 1 in the second embodiment mainly in that the second illumination section 25 is located downstream of the first illumination section 23 in the first conveying direction D1 and in that the imaging unit 30 has a first imaging section 31 and a second imaging section 32.

[0069] The second illumination section 25 in this embodiment has a similar configuration to the second illumination section 25 in the second embodiment. However, as described above, the second illumination section 25 is located downstream of the first illumination section 23 in the first transport direction D1.

[0070] The first imaging section 31 in this embodiment has the same configuration as the imaging unit 30 in the second embodiment. Therefore, the first imaging section 31 in this embodiment is a line sensor camera, is located approximately directly above the first illumination section 23, and intersects with the first straight line 23a. The first imaging section 31 is disposed so that the imaging range extends in a direction approximately perpendicular to the first conveying direction D1 and is located at a portion of the inspection object 60 through which the light L3 from the first illumination section 23 passes or in the vicinity of the portion. The first imaging section 31 captures an image of the light L3 from the first illumination section 23 that passes through the inspection object 60.

[0071] The second imaging section 32 of this embodiment is a line sensor camera, similar to the first imaging section 31. The second imaging section 32 is located above the inspection object 60 and closer to the roller 12 than the first illumination section 23 and the first imaging section 31 in a direction parallel to the first conveying direction D1, and does not intersect with the first straight line 23a and the second straight line 25a. The second imaging section 32 is disposed so that an imaging range extends in a direction substantially perpendicular to the first conveying direction D1 and the imaging range is located at a portion of the inspection object 60 through which the light L5 from the second illumination section 25 passes or in the vicinity of the portion. The second imaging section 32 captures an image of the light L5 from the second illumination section 25 that passes through the inspection object 60.

[0072] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0073] In this embodiment, similarly to the second embodiment, the inspection object 60 is placed on the support film 13 between the rollers 11 and 12 of the conveying device 10 so as to be located closer to the roller 11 than the illumination unit 21 and the imaging unit 30. The control unit CO controls the first illumination unit 23 to emit light L3. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the first conveying direction D1. For this reason, the first illumination unit 23 irradiates the light L3 through the support film 13 to the other surface 60S2 of the inspection object 60 conveyed in the first conveying direction D1 by the conveying device 10. At this time, the light L5 from the second illumination unit 25 is not emitted. The control unit CO controls the first imaging unit 31 to cause the first imaging unit 31 to capture images of light L3 from the first illumination unit 23 that passes through the object to be inspected 60 being transported in the first transport direction D1 at a predetermined time interval, and to output a two-dimensional image including the entirety of one surface 60S1 of the object to be inspected 60 to the inspection unit 40.

[0074] Moreover, as in the second embodiment, after the above-mentioned imaging by the first imaging unit 31 is completed, the control unit CO controls the second illumination unit 25 to emit light L5. Moreover, the control unit CO controls the conveying device 10 to convey the inspection object 60 in the second conveying direction D2, and returns the inspection object 60 to the position where the inspection object 60 was placed on the conveying device 10. Therefore, the second illumination unit 25 irradiates the other surface 60S2 of the inspection object 60 conveyed in the second conveying direction D2 by the conveying device 10 with light L5 through the support film 13. At this time, the light L3 from the first illumination unit 23 is not emitted. The control unit CO controls the second imaging unit 32 to cause the second imaging unit 32 to capture images of light L5 from the second illumination unit 25 that passes through the object to be inspected 60 being transported in the second transport direction D2 at predetermined time intervals, and to output a two-dimensional image including the entirety of one surface 60S1 of the object to be inspected 60 to the inspection unit 40.

[0075] That is, in this embodiment, the first imaging section 31 images the light L3 from the first illumination section 23 that passes through the object 60 to be inspected, and the second imaging section 32 images the light L5 from the second illumination section 25 that passes through the object 60 to be inspected.

[0076] The first straight line 23a in this embodiment intersects with the first imaging section 31. Therefore, in the same manner as in the second embodiment, the defect of the inspection object 60 may be displayed as a dark area in the image of the light L3 from the first illumination section 23 captured by the first imaging section 31. In addition, the second straight line 25a does not intersect with the second imaging section 32. In this embodiment, as in the second embodiment, the position and orientation of the second illumination section 25 with respect to the second imaging section 32 are adjusted so that most of the light L5 irradiated to the inspection object 60 by the second illumination section 25 and transmitted through the inspection object 60 without entering the defect of the inspection object 60 does not enter the second imaging section 32. Therefore, in the image of the light L5 from the second illumination section 25 captured by the second imaging section 32, the defect may be displayed as a bright area surrounded by a dark area.

[0077] As in the second embodiment, the inspection unit 40 of this embodiment determines the presence or absence of defects from dark areas in the image of light L3 from the first illumination unit 23 captured by the first imaging unit 31, and further determines the presence or absence of defects from bright areas in the image of light L5 from the second illumination unit 25 captured by the second imaging unit 32.

[0078] As in the second embodiment, the control unit CO outputs a control signal corresponding to a signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. As described above, the object 60 to be inspected is returned to the position where the object 60 was placed on the transport device 10. Therefore, as in the first embodiment, the position of the object 60 before inspection and the position of the object 60 after inspection are approximately the same.

[0079] The inspection device 1 of this embodiment, like the second embodiment, can detect even fine defects such as fibrous foreign matter.

[0080] In the inspection device 1 of the present embodiment, the imaging unit 30 has a first imaging section 31 that images the light L3 from the first illumination section 23 that passes through the object 60 to be inspected, and a second imaging section 32 that images the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, according to the inspection device 1 of the present embodiment, the degree of freedom of the position and orientation of the second illumination section 25 with respect to the object 60 can be improved compared to a case where the imaging unit 30 does not have the second imaging section 32, and defects can be more easily reflected in an image captured by the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, the inspection device 1 of the embodiment can further suppress a decrease in the detection accuracy of defects in the object 60 to be inspected.

[0081] (Fourth embodiment) Next, a fourth embodiment as a first aspect of the present invention will be described in detail with reference to Fig. 8. Note that components that are the same as or equivalent to those in the third embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0082] Fig. 8 is a diagram showing an inspection device according to a fourth embodiment of the present invention in the same manner as Fig. 1. As shown in Fig. 8, the inspection device 1 of this embodiment differs from the inspection device 1 of the third embodiment mainly in that the illumination unit 21 is composed of one illumination section and that the second imaging section 32 is inclined with respect to the vertical direction.

[0083] The illumination unit 21 of this embodiment has the same configuration as the illumination unit 21 of the first embodiment. Therefore, the illumination unit 21 of this embodiment is disposed below the support film 13 between the rollers 11 and 12, and is a line illumination composed of a plurality of LEDs arranged in parallel in a direction approximately perpendicular and approximately horizontal to the first conveying direction D1. In addition, a straight line 21a that is parallel to the optical axis of the illumination unit 21 and passes through the exit surface 21e of the illumination unit 21 is approximately parallel to the vertical, the first imaging section 31 intersects with this straight line 21a, and the second imaging section 32 does not intersect with this straight line 21a. The portion of the inspection object 60 through which the light L1 from the illumination unit 21 passes is a line extending in a direction approximately perpendicular to the first conveying direction D1. The imaging range of the first imaging section 31 is located in the portion of the inspection object 60 through which the light L1 from the illumination unit 21 passes or in the vicinity of the portion.

[0084] As described above, the second imaging section 32 of this embodiment is tilted with respect to the vertical direction. Specifically, the second imaging section 32 is tilted with respect to the vertical direction so that the imaging range extends in a direction substantially perpendicular to the first transport direction D1 and the imaging range is located at a portion of the inspection object 60 through which the light L1 from the illumination unit 21 passes or in the vicinity of the portion. In other words, the second imaging section 32 is disposed so that the imaging range is located in this manner.

[0085] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0086] In this embodiment, similarly to the third embodiment, the inspection object 60 is placed on the support film 13 between the rollers 11, 12 of the conveying device 10 so as to be located closer to the rollers 11 than the illumination unit 21 and the imaging unit 30. The control unit CO controls the illumination unit 21 to emit light L1. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the first conveying direction D1. For this reason, the illumination unit 21 irradiates light, via the support film 13, onto the other surface 60S2 of the inspection object 60 conveyed by the conveying device 10 in the first conveying direction D1. The control unit CO controls the first imaging unit 31 and the second imaging unit 32 to cause the first imaging unit 31 and the second imaging unit 32 to capture light L1 from the illumination unit 21 that passes through the object to be inspected 60 being transported in the first transport direction D1 at predetermined time intervals, and output two-dimensional images including the entirety of one surface 60S1 of the object to be inspected 60 to the inspection unit 40.

[0087] That is, in this embodiment, the first imaging section 31 that intersects with the straight line 21a and the second imaging section 32 that does not intersect with the straight line 21a each capture an image of the light L1 from the illumination unit 21 that passes through the object 60 to be inspected.

[0088] In this embodiment, since the first imaging section 31 intersects with the straight line 21a as described above, the defect of the inspection object 60 may be displayed as a dark area in the image of the light L1 from the illumination unit 21 captured by the first imaging section 31, as in the third embodiment. In addition, the straight line 21a does not intersect with the second imaging section 32. In this embodiment, as in the third embodiment, the position and orientation of the second imaging section 32 with respect to the illumination unit 21 are adjusted so that most of the light L1 irradiated to the inspection object 60 by the illumination unit 21 and transmitted through the inspection object 60 without entering the defect of the inspection object 60 does not enter the second imaging section 32. Therefore, the defect may be displayed as a bright area surrounded by a dark area in the image of the light L1 from the illumination unit 21 captured by the second imaging section 32.

[0089] As in the third embodiment, the inspection section 40 of this embodiment determines the presence or absence of defects from dark areas in the image of the light L1 from the lighting unit 21 captured by the first imaging section 31, and further determines the presence or absence of defects from bright areas in the image of the light L1 from the lighting unit 21 captured by the second imaging section 32.

[0090] As in the third embodiment, the control unit CO outputs a control signal corresponding to a signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. The control unit CO also controls the transport device 10 to transport the inspection object 60 in a second transport direction D2 that is the opposite direction to the first transport direction D1, and returns the inspection object 60 to the position where the inspection object 60 was placed on the transport device 10. Therefore, the position of the inspection object 60 before inspection and the position of the inspection object 60 after inspection are approximately the same. Note that the control unit CO does not have to cause the transport device 10 to transport the inspection object 60 in the second transport direction D2.

[0091] The inspection device 1 of this embodiment, like the third embodiment, can detect even fine defects such as fibrous foreign matter.

[0092] In the inspection device 1 of the present embodiment, the imaging unit 30 has a first imaging section 31 that images the light L3 from the first illumination section 23 that passes through the object 60 to be inspected, and a second imaging section 32 that images the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, according to the inspection device 1 of the present embodiment, the degree of freedom of the position and orientation of the second illumination section 25 with respect to the object 60 can be improved compared to a case where the imaging unit 30 does not have the second imaging section 32, and defects can be more easily reflected in an image captured by the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, the inspection device 1 of the embodiment can further suppress a decrease in the detection accuracy of defects in the object 60 to be inspected.

[0093] Fifth embodiment Next, a fifth embodiment of the present invention will be described as a second aspect. Note that components that are the same as or equivalent to those in the first embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0094] Fig. 9 is a diagram showing an inspection device according to the present embodiment. As shown in Fig. 9, the inspection device 1 according to the present embodiment differs from the inspection device 1 according to the first embodiment mainly in that an illumination unit 21 is disposed above the support film 13 between the rollers 11 and 12, and an imaging unit 30 is disposed below the support film 13 between the rollers 11 and 12.

[0095] The illumination unit 21 of this embodiment irradiates light L1 onto one surface 60S1 of the inspection object 60 transported by the transport device 10. In other words, it can be understood that the illumination unit 21 is disposed on the one surface 60S1 side of the inspection object 60 as a reference and irradiates the light L1 onto this one surface 60S1. FIG. 10 is a view of the inspection device 1 of FIG. 9 as seen from the downstream side of the first transport direction D1. For ease of understanding, the inspection object 60 is shown in a vertical cross section in FIG. 10. Also, in FIG. 10, the light L1 emitted from the illumination unit 21 is shown by a two-dot chain line. As shown in FIG. 10, the light L1 passes through the inspection object 60 from the one surface 60S1 side of the inspection object 60 toward the other surface 60S2 side.

[0096] The imaging unit 30 of this embodiment captures the light L1 from the illumination unit 21 that passes through the object 60 through the support film 13. That is, the imaging unit 30 is disposed on the other surface 60S2 side of the object 60 as a reference, and captures the light L1 from the illumination unit 21 that passes through the object 60. In this embodiment, the imaging unit 30 is a line sensor camera, and is positioned substantially directly below the illumination unit 21 and intersects with the straight line 21a. The imaging unit 30 is disposed so that the imaging range extends in a direction substantially perpendicular to the first transport direction D1 and the imaging range is located at a portion of the object 60 through which the light L1 from the illumination unit 21 passes or in the vicinity of the portion. The control unit CO controls the imaging unit 30 to capture the light that passes through the object 60 being transported to the imaging unit 30 at a predetermined time interval, and to output a two-dimensional image including the entire other surface 60S2 of the object 60 to the inspection unit 40.

[0097] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0098] In this embodiment, similarly to the first embodiment, the inspection object 60 is placed on the support film 13 between the rollers 11 and 12 of the conveying device 10 so as to be located closer to the rollers 11 than the illumination unit 21 and the imaging unit 30. The control unit CO controls the illumination unit 21 to emit light L1. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the first conveying direction D1. For this reason, the illumination unit 21 irradiates light L1 onto one side 60S1 of the inspection object 60 conveyed in the first conveying direction D1 by the conveying device 10. The control unit CO controls the imaging unit 30 to capture the light L1 from the illumination unit 21 that passes through the inspection object 60 conveyed in the first conveying direction D1 at a predetermined time interval, and outputs a two-dimensional image including the entire other side 60S2 of the inspection object 60 to the inspection section 40.

[0099] If there is a defect such as a foreign matter on one surface 60S1 or the other surface 60S2 of the object to be inspected 60, the defect may be shown as a dark area 72 surrounded by a bright area 71 in the image of light from the illumination unit 21 captured by the imaging unit 30, as shown in Figure 3, in the same manner as in the first embodiment.

[0100] The inspection section 40 of this embodiment determines the presence or absence of defects on one surface 60S1 and the other surface 60S2 of the inspection object 60 based on images captured by the imaging unit 30, in the same manner as in the first embodiment.

[0101] The control unit CO outputs a control signal corresponding to the signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. The control unit CO also controls the conveying device 10 to return the inspection object 60 to the position where the inspection object 60 was placed on the conveying device 10.

[0102] Meanwhile, the outer peripheral edge of the inspection object 60, which is the outer cover, is provided with a rib 61 protruding toward the other surface 60S2. For this reason, a part of the light from the illumination unit 21 may be incident on the rib 61 and emitted from the rib 61 toward the imaging unit 30, or may be reflected by the rib 61 toward the imaging unit 30. That is, the light passing through the rib 61 or the light reflected by the rib 61 may be reflected in an image captured by the imaging unit 30. When the light from the rib 61 overlaps with a portion of the inspection object 60 corresponding to the surface 60S1 or the surface 60S2 in the image, the light from the rib 61 may make it impossible to properly inspect the presence or absence of defects in this portion, and in this case, there is a concern that the inspection range for defects on the surface of the inspection object may be narrowed.

[0103] Therefore, the inspection device 1 of this embodiment includes an illumination unit 21, an imaging unit 30, and an inspection section 40. The illumination unit 21 is disposed on the side of the one surface 60S1 of the inspection object 60, which includes one surface 60S1 curved convexly and the other surface 60S2 curved concavely opposite to the one surface 60S1 and has translucency, and irradiates the one surface 60S1 with light. The imaging unit 30 is disposed on the other surface 60S2 of the inspection object 60, and captures the light L1 from the illumination unit 21 that passes through the inspection object 60. The inspection section 40 judges the presence or absence of a defect in the inspection object 60 based on the image captured by the imaging unit 30. In the inspection device 1 of this embodiment, the imaging unit 30 is disposed on the other surface 60S2 of the inspection object 60. In addition, a rib 61 protruding from the other surface 60S2 is provided on the outer periphery of the inspection object 60. Of the light L1 from the illumination unit 21, a part of the light incident on the object 60 from one surface 60S1, or a part of the light incident on the object 60 from one surface 60S1 and exiting from the other surface 60S2 of the object 60 may be incident on the rib 61 or reflected by the rib 61 and head toward the imaging unit 30. Even if the light heads toward the imaging unit 30 from the rib 61 in this way, the light is likely to head toward the imaging unit 30 without passing through the other surface 60S2 or the one surface 60S1 in the vicinity of the rib 61. On the other hand, unlike this embodiment, when the illumination unit 21 is disposed on the other surface 60S2 side with respect to the object 60 as a reference and the imaging unit 30 is disposed on the one surface 60S1 side with respect to the object 60 as a reference, the light from the illumination unit 21 headed toward the imaging unit from the rib 61 is likely to head toward the imaging unit 30 via the other surface 60S2 or the one surface 60S1 in the vicinity of the rib 61. In this case, most of the light traveling from the rib 61 toward the imaging unit 30 is likely to overlap with light traveling toward the imaging unit 30 via the other surface 60S2 or one surface 60S1 in the vicinity of the rib 61 without passing through the rib 61, and enter the imaging unit 30. In other words, in an image captured by the imaging unit 30, the light from the rib 61 is likely to overlap with the other surface 60S2 or one surface 60S1 in the vicinity of the rib 61.Therefore, the light from the rib 61 toward the imaging unit 30 tends to make it impossible to properly detect defects on the other surface 60S2 or the one surface 60S1 in the vicinity of the rib 61. Therefore, in the inspection device 1 of this embodiment, even if light is directed from the rib 61 toward the imaging unit 30, the light is less likely to overlap with light directed toward the imaging unit 30 via the other surface 60S2 or the one surface 60S1 in the vicinity of the rib 61 without passing through the rib 61, compared to a case in which the illumination unit 21 is arranged on the other surface 60S2 side with respect to the object to be inspected 60 and the imaging unit 30 is arranged on the one surface 60S1 side with respect to the object to be inspected 60. Therefore, the inspection device 1 of this embodiment can suppress the inability to properly detect defects on the other surface 60S2 or the one surface 60S1 in the vicinity of the rib 61. Therefore, the inspection device 1 of this embodiment can prevent the inspection range for defects on the surface of the object to be inspected 60 from becoming narrower, even if a rib 61 protruding from the other surface 60S2 is provided on the outer peripheral edge of the object to be inspected 60 and light is directed from the rib 61 toward the imaging unit 30.

[0104] Sixth embodiment Next, a sixth embodiment as a second aspect of the present invention will be described in detail with reference to Fig. 11. Note that components that are the same as or equivalent to those in the fifth embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0105] Fig. 11 is a diagram showing the inspection device in this embodiment similarly to Fig. 9. As shown in Fig. 11, the inspection device 1 in this embodiment is mainly different from the inspection device 1 in the fifth embodiment in that the illumination unit 21 has a first illumination section 23 and a second illumination section 25. In Fig. 11, light L3 emitted from the first illumination section 23 and light L5 emitted from the second illumination section 25 are indicated by two-dot chain lines.

[0106] The first illumination section 23 in this embodiment has the same configuration as the illumination unit 21 in the fifth embodiment. Therefore, the first illumination section 23 in this embodiment is disposed above the object 60 to be inspected, and is a line illumination consisting of a plurality of LEDs arranged in parallel in a direction substantially perpendicular and substantially horizontal to the first conveying direction D1. In addition, a first straight line 23a that is parallel to the optical axis of the first illumination section 23 and passes through the light emission surface 23e of the first illumination section 23 is substantially parallel to the vertical, and the imaging unit 30 intersects with this first straight line 23a. The first illumination section 23 irradiates light L3 onto one surface 60S1 of the object 60 to be inspected that is conveyed by the conveying device 10, and this light L3 passes through the object 60 to be inspected from the one surface 60S1 side to the other surface 60S2 side of the object 60 to be inspected. The portion of the inspection object 60 through which the light L3 from the first illumination unit 23 passes forms a line extending in a direction substantially perpendicular to the first transport direction D1.

[0107] On the other hand, the second illumination section 25 of this embodiment is disposed above the object 60 and closer to the roller 11 than the first illumination section 23. The second illumination section 25 is a line illumination consisting of a plurality of LEDs arranged in parallel in a direction substantially perpendicular and substantially horizontal to the first conveying direction D1, similar to the first illumination section 23. A second straight line 25a, which is parallel to the optical axis of the second illumination section 25 and passes through the light emission surface 25e of the second illumination section 25, extends in the vertical direction, but is inclined downward toward the roller 12 side and is not parallel to the first straight line 23a. This second straight line 25a passes between the imaging unit 30 and the roller 12 and does not intersect with the imaging unit 30. The second illumination section 25 irradiates light L5 onto one surface 60S1 of the object 60 to be inspected, which is conveyed by the conveying device 10, and this light L5 passes through the object 60 from one surface 60S1 side to the other surface 60S2 side of the object 60 to be inspected. The portion of the object 60 through which the light L5 from the second illumination section 25 passes forms a line extending in a direction substantially perpendicular to the first transport direction D1, and overlaps with the portion of the object 60 through which the light L3 from the first illumination section 23 passes. The imaging range of the imaging unit 30 is located at the portion where the portion of the object 60 through which the light L3 from the first illumination section 23 passes and the portion through which the light L5 from the second illumination section 25 passes overlap, or in the vicinity of this overlapping portion. In other words, the first illumination section 23, the second illumination section 25, and the imaging unit 30 are arranged so that the imaging range of the imaging unit 30 is positioned in this way.

[0108] In addition, the illumination unit 21 does not emit light L5 from the second illumination section 25 when emitting light L3 from the first illumination section 23, and does not emit light L3 from the first illumination section 23 when emitting light L5 from the second illumination section 25. In other words, the time when the first illumination section 23 irradiates the one surface 60S1 of the inspection object 60 with light L3 and the time when the second illumination section 25 irradiates the one surface 60S1 of the inspection object 60 with light L5 are different from each other.

[0109] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0110] In this embodiment, the object 60 to be inspected is placed on the support film 13, as in the fifth embodiment. The control unit CO controls the first illumination unit 23 to emit light L3. The control unit CO also controls the conveying device 10 to convey the object 60 to be inspected in the first conveying direction D1. For this reason, the first illumination unit 23 irradiates light L3 onto one side 60S1 of the object 60 to be inspected, which is conveyed by the conveying device 10 in the first conveying direction D1. At this time, the light L5 from the second illumination unit 25 is not emitted. The control unit CO controls the imaging unit 30 to capture the light L3 from the first illumination unit 23 that passes through the object 60 to be inspected, which is conveyed in the first conveying direction D1, at a predetermined time interval, and outputs a two-dimensional image including the entire other side 60S2 of the object 60 to the inspection unit 40.

[0111] In this embodiment, after the imaging by the imaging unit 30 is completed, the control unit CO controls the second illumination unit 25 to emit light L5. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the second conveying direction D2, and returns the inspection object 60 to the position where the inspection object 60 was placed on the conveying device 10. For this reason, the second illumination unit 25 irradiates light onto one side 60S1 of the inspection object 60 conveyed in the second conveying direction D2 by the conveying device 10. At this time, the light L3 from the first illumination unit 23 is not emitted. The control unit CO controls the imaging unit 30 to capture the light L5 from the second illumination unit 25 that passes through the inspection object 60 conveyed in the second conveying direction D2 at a predetermined time interval, and outputs a two-dimensional image including the entire other side 60S2 of the inspection object 60 to the inspection unit 40.

[0112] As described above, in this embodiment, the first straight line 23a and the second straight line 25a are not parallel to each other. Therefore, it can be understood that the illumination unit 21 has the first illumination section 23 that irradiates the one surface 60S1 of the object 60 with light L3 from a first direction, and the second illumination section 25 that irradiates the one surface 60S1 of the object 60 with light L5 from a second direction different from the first direction. In addition, it can be understood that the imaging unit 30 individually images the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 that pass through the object 60.

[0113] The inspection unit 40 of this embodiment judges the presence or absence of a defect based on an image captured by the light L3 from the first illumination unit 23, and further judges the presence or absence of a defect based on an image captured by the light L5 from the second illumination unit 25. Specifically, the inspection unit 40 judges the presence or absence of a defect from a dark area in an image captured by the light L3 from the first illumination unit 23. The first straight line 23a of this embodiment intersects with the imaging unit 30. Therefore, similar to the fifth embodiment, a defect may be displayed as a dark area in the image captured by the imaging unit 30 of the light L3 from the first illumination unit 23. Similarly to the fifth embodiment, the inspection unit 40 of this embodiment extracts an area having a luminance value lower than a predetermined threshold in the image captured by the imaging unit 30 of the light L3 from the first illumination unit 23, and calculates the area of ​​the extracted area. Then, if the calculated area is larger than the predetermined area, a signal indicating the presence of a defect is output to the control unit CO.

[0114] On the other hand, the second straight line 25a does not intersect with the imaging unit 30. Therefore, compared to the case where the second straight line 25a intersects with the imaging unit 30, among the light L5 irradiated to the inspection object 60 by the second illumination section 25, the light that does not enter the defects on the one surface 60S1 and the other surface 60S2 of the inspection object 60 and passes through the inspection object 60 from the one surface 60S1 side to the other surface 60S2 side is less likely to enter the imaging unit 30. In this embodiment, the position and orientation of the second illumination section 25 with respect to the imaging unit 30 are adjusted so that among the light L5 irradiated to the inspection object 60 by the second illumination section 25, most of the light that passes through the inspection object 60 in this way does not enter the imaging unit 30. On the other hand, among the light L5 irradiated to the inspection object 60 by the second illumination section 25, most of the light that enters the defects is absorbed or reflected by the defects. Therefore, the light that is reflected by the defects and passes through the inspection object 60 can enter the imaging unit 30. 6, in the image of light L5 from the second illumination section 25 captured by the imaging unit 30, the defect may be shown as a bright area 71 surrounded by a dark area 72. As in the second embodiment, the inspection section 40 of this embodiment determines the presence or absence of a defect based on an image captured with light L3 from the first illumination section 23, and further determines the presence or absence of a defect based on an image captured with light L5 from the second illumination section 25, and outputs a signal according to the determination to the control section CO.

[0115] The control unit CO outputs a control signal corresponding to the signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. As described above, the object 60 to be inspected is returned to the position where the object 60 was placed on the transport device 10. Therefore, similar to the fifth embodiment, the position of the object 60 before inspection and the position of the object 60 after inspection are substantially the same.

[0116] As described above, in the inspection device 1 of the present embodiment, the illumination unit 21 includes the first illumination section 23 that irradiates the one surface 60S1 of the object 60 with light L3 from a first direction, and the second illumination section 25 that irradiates the one surface 60S1 of the object 60 with light L5 from a second direction different from the first direction. The imaging unit 30 individually captures the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 that pass through the object 60. The imaging unit 30 also intersects with the first straight line 23a but does not intersect with the second straight line 25a. The inspection section 40 also determines the presence or absence of a defect from the dark portion 72 in the image captured with the light L3 from the first illumination section 23, and determines the presence or absence of a defect from the bright portion 71 in the image captured with the light L5 from the second illumination section 25. Incidentally, since light propagates while diffusing, if the defect is thin and fibrous, such as a hair or lint, such a defect tends not to be shown as a dark area 72 in an image captured with light L3 from the first illumination unit 23. However, the inspection device 1 of this embodiment can make such a defect appear as a bright area 71 in an image captured with light L5 from the second illumination unit 25. Therefore, the inspection device 1 of this embodiment can detect even thin defects such as fibrous foreign matter.

[0117] In addition, in the inspection device 1 of this embodiment, the time when the first illumination section 23 irradiates the one surface 60S1 of the inspection object 60 with the light L3 and the time when the second illumination section 25 irradiates the one surface 60S1 of the inspection object 60 with the light L5 are different from each other. Therefore, the light L5 from the second illumination section 25 is not reflected in the image in which the light L3 from the first illumination section 23 is captured. Furthermore, the light L3 from the first illumination section 23 is not reflected in the image in which the light L5 from the second illumination section 25 is captured. Therefore, even if the imaging unit 30 does not have, for example, a first imaging section that captures the light L3 from the first illumination section 23 and a second imaging section that captures the light L5 from the second illumination section 25, the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 can be individually captured.

[0118] From the viewpoint of increasing the accuracy of detection of fine defects such as fibrous foreign matter, it is preferable that the light L5 from the second illumination unit 25 is collimated light or light that is focused on one surface 60S1 of the inspection object 60. With this configuration, the luminance of the bright portion 71 when the defect is projected as the bright portion 71 can be increased compared to the case where the light L5 from the second illumination unit 25 is diffused light, and the accuracy of detection of fine defects such as fibrous foreign matter can be increased.

[0119] Seventh embodiment Next, a seventh embodiment as a second aspect of the present invention will be described in detail with reference to Fig. 12. Note that components that are the same as or equivalent to those in the sixth embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0120] Fig. 12 is a diagram showing the inspection device in this embodiment similarly to Fig. 9. As shown in Fig. 12, the inspection device 1 in this embodiment mainly differs from the inspection device 1 in the sixth embodiment in that the second illumination section 25 is located downstream of the first illumination section 23 in the first conveying direction D1 and the imaging unit 30 has a first imaging section 31 and a second imaging section 32.

[0121] The second illumination section 25 in this embodiment has a similar configuration to the second illumination section 25 in the sixth embodiment. However, as described above, the second illumination section 25 is located downstream of the first illumination section 23 in the first transport direction D1.

[0122] The first imaging section 31 in this embodiment has the same configuration as the imaging unit 30 in the sixth embodiment. For this reason, the first imaging section 31 in this embodiment is a line sensor camera, is located substantially directly below the first illumination section 23, and intersects with the first straight line 23a. The first imaging section 31 is disposed so that an imaging range extends in a direction substantially perpendicular to the first transport direction D1, and the imaging range is located at a portion of the inspection object 60 through which the light L3 from the first illumination section 23 passes or in the vicinity of the portion. The first imaging section 31 captures an image of the light L3 from the first illumination section 23 that passes through the inspection object 60.

[0123] The second imaging section 32 of this embodiment is a line sensor camera, similar to the first imaging section 31. The second imaging section 32 is located below the support film 13 between the rollers 11 and 12 and closer to the roller 12 than the first illumination section 23 and the first imaging section 31 in a direction parallel to the first conveying direction D1, and does not intersect with the first straight line 23a and the second straight line 25a. The second imaging section 32 is disposed so that an imaging range extends in a direction substantially perpendicular to the first conveying direction D1 and the imaging range is located at a portion of the inspection object 60 through which the light L5 from the second illumination section 25 passes or in the vicinity of the portion. The second imaging section 32 captures an image of the light L5 from the second illumination section 25 that passes through the inspection object 60.

[0124] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0125] In this embodiment, the object 60 to be inspected is placed on the support film 13, as in the sixth embodiment. The control unit CO controls the first illumination unit 23 to emit light L3. The control unit CO also controls the conveying device 10 to convey the object 60 to be inspected in the first conveying direction D1. For this reason, the first illumination unit 23 irradiates light L3 onto one side 60S1 of the object 60 to be inspected, which is conveyed by the conveying device 10 in the first conveying direction D1. At this time, the light L5 from the second illumination unit 25 is not emitted. The control unit CO controls the first imaging unit 31 to image the light L3 from the first illumination unit 23 that passes through the object 60 to be inspected, which is conveyed in the first conveying direction D1, at a predetermined time interval, and outputs a two-dimensional image including the entire other side 60S2 of the object 60 to the inspection unit 40.

[0126] Moreover, as in the sixth embodiment, after the first imaging unit 31 has completed the imaging, the control unit CO controls the second illumination unit 25 to emit light L5. The control unit CO also controls the conveying device 10 to convey the inspection object 60 in the second conveying direction D2, and returns the inspection object 60 to the position where the inspection object 60 was placed on the conveying device 10. For this reason, the second illumination unit 25 irradiates light L5 onto one surface 60S1 of the inspection object 60 conveyed in the second conveying direction D2 by the conveying device 10. At this time, light L3 from the first illumination unit 23 is not emitted. The control unit CO controls the second imaging unit 32 to cause the second imaging unit 32 to image the light L5 from the second illumination unit 25 that passes through the object to be inspected 60 being transported in the second transport direction D2 at a predetermined time interval, and output a two-dimensional image including the entire other surface 60S2 of the object to be inspected 60 to the inspection unit 40.

[0127] That is, in this embodiment, the first imaging section 31 images the light L3 from the first illumination section 23 that passes through the object 60 to be inspected, and the second imaging section 32 images the light L5 from the second illumination section 25 that passes through the object 60 to be inspected.

[0128] The first straight line 23a in this embodiment intersects with the first imaging section 31. Therefore, in the same manner as in the sixth embodiment, the defect of the inspection object 60 may be displayed as a dark area in the image of the light L3 from the first illumination section 23 captured by the first imaging section 31. In addition, the second straight line 25a does not intersect with the second imaging section 32. In this embodiment, as in the sixth embodiment, the position and orientation of the second illumination section 25 with respect to the second imaging section 32 are adjusted so that most of the light L5 irradiated to the inspection object 60 by the second illumination section 25 and transmitted through the inspection object 60 without entering the defect of the inspection object 60 does not enter the second imaging section 32. Therefore, in the image of the light L5 from the second illumination section 25 captured by the second imaging section 32, the defect may be displayed as a bright area surrounded by a dark area.

[0129] As in the sixth embodiment, the inspection unit 40 of this embodiment determines the presence or absence of a defect from dark areas in the image of light L3 from the first illumination unit 23 captured by the first imaging unit 31, and further determines the presence or absence of a defect from bright areas in the image of light L5 from the second illumination unit 25 captured by the second imaging unit 32.

[0130] As in the sixth embodiment, the control unit CO outputs a control signal corresponding to a signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. As described above, the object 60 to be inspected is returned to the position where the object 60 was placed on the transport device 10. Therefore, as in the fifth embodiment, the position of the object 60 before inspection and the position of the object 60 after inspection are approximately the same.

[0131] The inspection device 1 of this embodiment, like the sixth embodiment, can detect even fine defects such as fibrous foreign matter.

[0132] In the inspection device 1 of the present embodiment, the imaging unit 30 has a first imaging section 31 that images the light L3 from the first illumination section 23 that passes through the object 60 to be inspected, and a second imaging section 32 that images the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, according to the inspection device 1 of the present embodiment, the degree of freedom of the position and orientation of the second illumination section 25 with respect to the object 60 can be improved compared to a case where the imaging unit 30 does not have the second imaging section 32, and defects can be more easily reflected in an image captured by the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, the inspection device 1 of the embodiment can further suppress a decrease in the detection accuracy of defects in the object 60 to be inspected.

[0133] Eighth embodiment Next, an eighth embodiment as a second aspect of the present invention will be described in detail with reference to Fig. 13. Note that components that are the same as or equivalent to those in the seventh embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0134] Fig. 13 is a diagram showing the inspection device in this embodiment similar to Fig. 9. As shown in Fig. 13, the inspection device 1 in this embodiment mainly differs from the inspection device 1 in the seventh embodiment in that the illumination unit 21 is composed of one illumination section and that the second imaging section 32 is inclined with respect to the vertical direction.

[0135] The illumination unit 21 of this embodiment has the same configuration as the illumination unit 21 of the fifth embodiment. Therefore, the illumination unit 21 of this embodiment is arranged above the object 60 to be inspected, and is a line illumination composed of a plurality of LEDs arranged in parallel in a direction substantially perpendicular and substantially horizontal to the first transport direction D1. In addition, a straight line 21a that is parallel to the optical axis of the illumination unit 21 and passes through the emission surface 21e of the illumination unit 21 is substantially parallel to the vertical, the first imaging section 31 intersects with this straight line 21a, and the second imaging section 32 does not intersect with this straight line 21a. The portion of the object 60 through which the light L1 from the illumination unit 21 passes is linear and extends in a direction substantially perpendicular to the first transport direction D1. The imaging range of the first imaging section 31 is located in the portion of the object 60 through which the light L1 from the illumination unit 21 passes or in the vicinity of the portion.

[0136] As described above, the second imaging section 32 of this embodiment is tilted with respect to the vertical direction. Specifically, the second imaging section 32 is tilted with respect to the vertical direction so that the imaging range extends in a direction substantially perpendicular to the first transport direction D1 and the imaging range is located at a portion of the inspection object 60 through which the light L1 from the illumination unit 21 passes or in the vicinity of the portion. In other words, the second imaging section 32 is disposed so that the imaging range is located in this manner.

[0137] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0138] In this embodiment, the object 60 to be inspected is placed on the support film 13, as in the seventh embodiment. The control unit CO controls the illumination unit 21 to emit light L1. The control unit CO also controls the transport device 10 to transport the object 60 to be inspected in the first transport direction D1. For this reason, the illumination unit 21 irradiates light L1 onto one surface 60S1 of the object 60 to be inspected, which is transported by the transport device 10 in the first transport direction D1. The control unit CO controls the first imaging unit 31 and the second imaging unit 32 to capture the light L1 from the illumination unit 21 that passes through the object 60 to be inspected transported in the first transport direction D1 at a predetermined time interval, and outputs two-dimensional images including the entire other surface 60S2 of the object 60 to the inspection unit 40.

[0139] That is, in this embodiment, the first imaging section 31 that intersects with the straight line 21a and the second imaging section 32 that does not intersect with the straight line 21a each capture an image of the light L1 from the illumination unit 21 that passes through the object 60 to be inspected.

[0140] In this embodiment, since the first imaging section 31 intersects with the straight line 21a as described above, the defect of the inspection object 60 may be displayed as a dark area in the image of the light L1 from the illumination unit 21 captured by the first imaging section 31, as in the seventh embodiment. In addition, the straight line 21a does not intersect with the second imaging section 32. In this embodiment, as in the seventh embodiment, the position and orientation of the second imaging section 32 with respect to the illumination unit 21 are adjusted so that most of the light L1 irradiated to the inspection object 60 by the illumination unit 21 and transmitted through the inspection object 60 without entering the defect of the inspection object 60 does not enter the second imaging section 32. Therefore, the defect may be displayed as a bright area surrounded by a dark area in the image of the light L1 from the illumination unit 21 captured by the second imaging section 32.

[0141] As in the seventh embodiment, the inspection section 40 of this embodiment determines the presence or absence of defects from dark areas in the image of the light L1 from the lighting unit 21 captured by the first imaging section 31, and further determines the presence or absence of defects from bright areas in the image of the light L1 from the lighting unit 21 captured by the second imaging section 32.

[0142] As in the seventh embodiment, the control unit CO outputs a control signal corresponding to a signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result. The control unit CO also controls the transport device 10 to transport the inspection object 60 in a second transport direction D2 that is the opposite direction to the first transport direction D1, and returns the inspection object 60 to the position where the inspection object 60 was placed on the transport device 10. Therefore, the position of the inspection object 60 before inspection and the position of the inspection object 60 after inspection are approximately the same. Note that the control unit CO does not have to cause the transport device 10 to transport the inspection object 60 in the second transport direction D2.

[0143] The inspection device 1 of this embodiment, like the seventh embodiment, can detect even a thin defect such as a fibrous foreign matter.

[0144] In the inspection device 1 of the present embodiment, the imaging unit 30 has a first imaging section 31 that images the light L3 from the first illumination section 23 that passes through the object 60 to be inspected, and a second imaging section 32 that images the light from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, according to the inspection device 1 of the present embodiment, the degree of freedom of the position and orientation of the second illumination section 25 with respect to the object 60 can be improved compared to a case where the imaging unit 30 does not have the second imaging section 32, and defects can be more easily reflected in an image captured by the light L5 from the second illumination section 25 that passes through the object 60 to be inspected. Therefore, the inspection device 1 of the embodiment can further suppress a decrease in the detection accuracy of defects in the object 60 to be inspected.

[0145] Ninth embodiment Next, a ninth embodiment as a second aspect of the present invention will be described in detail with reference to Fig. 14. Note that components that are the same as or equivalent to those in the fifth embodiment will be given the same reference numerals and will not be described again unless otherwise specified.

[0146] Fig. 14 is a diagram showing the inspection device in this embodiment similarly to Fig. 9. As shown in Fig. 14, the inspection device 1 in this embodiment is mainly different from the inspection device 1 in the fifth embodiment in that it includes a separate illumination unit 121 and a separate imaging unit 130.

[0147] The other lighting unit 121 of this embodiment has the same configuration as the lighting unit 21 of the first embodiment, and is disposed below the support film 13 on the downstream side of the lighting unit 21 and the imaging unit 30 in the first conveying direction D1. The other lighting unit 121 irradiates the other surface 60S2 of the inspection object 60 conveyed by the conveying device 10 with light L11 through the support film 13. That is, the other lighting unit 121 is disposed on the other surface 60S2 side with respect to the inspection object 60 as a reference, and irradiates the other surface 60S2 with light L11. In addition, a straight line 121a that is parallel to the optical axis of the other lighting unit 121 and passes through the light emission surface 121e of the other lighting unit 121 is approximately parallel to the straight line 21a, but the straight line 121a and the straight line 21a may be non-parallel, and the straight line 121a and the straight line 21a may be non-parallel to the vertical direction. Furthermore, the distance between the illumination unit 21 and the other illumination unit 121 in the direction parallel to the first transport direction D1 is smaller than the width of the object to be inspected 60 in the direction parallel to the first transport direction D1, but may be larger than this width. Furthermore, in the vertical direction perpendicular to the first transport direction D1, the exit surface 121e of the other illumination unit 121 is located closer to the support film 13 than the imaging unit 30, but the positional relationship between the exit surface 121e and the imaging unit 30 is not particularly limited.

[0148] The other imaging unit 130 of this embodiment has the same configuration as the imaging unit 30 of the first embodiment, and is disposed downstream of the illumination unit 21 and the imaging unit 30 in the first conveying direction D1 and above the object to be inspected 60, and captures the light L11 from the other illumination unit 121 that passes through the object to be inspected 60. That is, the other imaging unit 130 is disposed on one surface 60S1 side of the object to be inspected 60 as a reference, and captures the light L11 from the other illumination unit 121 that passes through the object to be inspected 60. In this embodiment, the other imaging unit 130 is a line sensor camera, and is positioned approximately directly above the other illumination unit 121 and intersects with the above-mentioned straight line 121a. In addition, in the vertical direction, the other imaging unit 130 is positioned on the opposite side to the support film 13 side from the exit surface 21e of the illumination unit 21, but the positional relationship between the other imaging unit 130 and the exit surface 21e is not particularly limited.

[0149] Next, an operation of inspecting the object 60 for defects in the inspection device 1 of this embodiment will be described.

[0150] In this embodiment, the object 60 to be inspected is placed on the support film 13, as in the fifth embodiment. The control unit CO controls the illumination unit 21 to emit light L1. The control unit CO also controls the conveying device 10 to convey the object 60 to be inspected in the first conveying direction D1. For this reason, the illumination unit 21 irradiates the light L1 onto one side 60S1 of the object 60 to be inspected, which is conveyed in the first conveying direction D1 by the conveying device 10. At this time, the light L11 from another illumination unit 121 is not emitted. The control unit CO controls the imaging unit 30 to capture the light L1 from the illumination unit 21 that passes through the object 60 to be inspected, which is conveyed in the first conveying direction D1, at a predetermined time interval, and outputs a two-dimensional image including the entire other side 60S2 of the object 60 to the inspection unit 40.

[0151] After the imaging unit 30 has completed the imaging, the control unit CO controls the other illumination unit 121 to emit light L11. The control unit CO controls the transport device 10 to transport the object 60 to the second transport direction D2, and returns the object 60 to the position where the object 60 was placed on the transport device 10. For this reason, the other illumination unit 121 irradiates light L11 onto one surface 60S1 of the object 60 transported in the second transport direction D2 by the transport device 10. At this time, the light L1 from the illumination unit 21 is not emitted. The control unit CO controls another imaging unit 130 to capture light L11 from another illumination unit 121 that passes through the object to be inspected 60 being transported in the second transport direction D2 at a predetermined time interval, and outputs a two-dimensional image including the entire other surface 60S2 of the object to be inspected 60 to the inspection section 40.

[0152] That is, in this embodiment, the imaging unit 30 captures the light L1 from the illumination unit 21 that passes through the object 60 to be inspected, and another imaging unit 130 captures the light L11 from another illumination unit 121 that passes through the object 60 to be inspected.

[0153] In this embodiment, similarly to the fifth embodiment, the inspection section 40 determines the presence or absence of a defect from a bright portion in an image of light L1 from the illumination unit 21 captured by the imaging unit 30. Also, the inspection section 40 determines the presence or absence of a defect from a bright portion in an image of light L11 from another illumination unit 121 captured by another imaging unit 130.

[0154] As in the fifth embodiment, the control unit CO outputs a control signal corresponding to a signal input from the inspection unit 40 to the display unit 50, and causes the display unit 50 to display the inspection result.

[0155] In this embodiment, the presence or absence of a defect is determined from an image of light L1 passing through the inspection object 60 from one surface 60S1 side to the other surface 60S2 side, and an image of light L11 passing through the inspection object 60 from the other surface 60S2 side to the one surface 60S1 side. Therefore, compared to a case where the separate illumination unit 121 and the separate imaging unit 130 are not provided, the detection accuracy of defects on the surface of the inspection object 60 can be improved.

[0156] The other illumination unit 121 and the other imaging unit 130 may be disposed upstream of the illumination unit 21 and the imaging unit 30 in the first transport direction D1. The imaging by the other imaging unit 130 may be performed when the inspection object 60 is transported in the first transport direction D1. In this case, it is preferable that the other imaging unit 130 is separated from the illumination unit 21 so that the light L1 from the illumination unit 21 is not incident. For example, it is preferable that the distance between the illumination unit 21 and the other imaging unit 130 in the direction parallel to the first transport direction D1 is larger than the width of the inspection object 60 in the direction parallel to the first transport direction D1. In this way, imaging by the other imaging unit 130 can be performed after imaging by the imaging unit 30 is completed. Also, when the inspection object 60 is transported in the first transport direction D1, the illumination unit 21 and another illumination unit 121 may alternately irradiate the light L1 and L11 at a predetermined time interval, the imaging unit 30 may capture the light L1 in synchronization with the illumination unit 21, and the other imaging unit 130 may capture the light L11 in synchronization with the other illumination unit 121. Also, any of the second to fourth embodiments may be applied to the other illumination unit 121 and the other imaging unit 130, and for example, the other illumination unit 121 may have the same configuration as the illumination unit 21 of the second embodiment shown in FIG. Also, any of the sixth to eighth embodiments may be applied to the illumination unit 21 and the imaging unit 30, and for example, the illumination unit 21 may have the same configuration as the illumination unit 21 of the sixth embodiment shown in FIG.

[0157] Although the first and second aspects of the present invention have been described above using the above-mentioned embodiments as examples, the present invention is not limited to these.

[0158] For example, in the first to ninth embodiments, the inspection object 60 is an outer cover provided with the rib 61 around the entire circumference of the outer periphery. However, the inspection object 60 only needs to have a light-transmitting property, a convexly curved surface 60S1, and a concavely curved surface 60S2 opposite the surface 60S1. For example, the rib 61 may be provided on a part of the outer periphery of the inspection object 60, or the rib 61 may not be provided on the outer periphery of the inspection object 60. Also, a part of the inspection object 60 may be colorless and transparent, and another part of the inspection object 60 may be colored and transparent.

[0159] In the first to ninth embodiments, the illumination unit 21 that irradiates the object 60 with white light has been described as an example. In the ninth embodiment, the illumination unit 121 that irradiates the object 60 with white light has been described as an example. However, the color of the light that the illumination unit 21 or the illumination unit 121 irradiates the object 60 is not particularly limited. In addition, when a part of the object 60 is colorless and transparent and another part of the object 60 is colored and transparent, it is preferable that the color of the light that the illumination unit 21 or the illumination unit 121 irradiates the object 60 is approximately the same color as the color of the colored and transparent part of the object 60. By adopting such a configuration, unevenness in the brightness of the image due to differences in color is suppressed, and the detection accuracy of the defect of the object 60 can be suppressed from decreasing.

[0160] In the second, third, sixth and seventh embodiments, the inspection section 40 is described as an example in which the presence or absence of a defect is determined from a dark portion in an image captured with the light L3 from the first illumination section 23, and the presence or absence of a defect is determined from a bright portion in an image captured with the light L5 from the second illumination section 25. However, in a case where the illumination unit 21 has the first illumination section 23 that irradiates the other surface 60S2 of the object to be inspected 60 with the light L3 from a first direction and the second illumination section 25 that irradiates the other surface 60S2 with the light from a second direction different from the first direction, and the imaging unit 30 individually images the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 that pass through the object to be inspected 60, from the viewpoint of suppressing a decrease in the detection accuracy of the defect in the object to be inspected 60, the inspection section 40 may determine the presence or absence of a defect based on the image captured by the imaging unit 30. In such an inspection device, since the first direction and the second direction are different from each other, the absorption, reflection, refraction, etc. of light caused by defects in the inspection object 60 when light is irradiated from the first direction is different from that when light is irradiated from the second direction. Therefore, a defect that is difficult to show in an image when light is irradiated from the first direction may be easily shown in an image when light is irradiated from the second direction, and a defect that is difficult to show in an image when light is irradiated from the second direction may be easily shown in an image when light is irradiated from the second direction. Therefore, such an inspection device can suppress a decrease in the detection accuracy of defects in the inspection object 60 compared to a case where the illumination unit 21 does not have the second illumination section 25.

[0161] In the second and sixth embodiments, the imaging unit 30 is described as being parallel to the optical axis of the second illumination unit 25 and does not intersect with the second straight line 25a passing through the light exit surface 25e of the second illumination unit 25. However, in the second and sixth embodiments, when the first straight line 23a and the second straight line 25a are non-parallel, the imaging unit 30 may intersect with the second straight line 25a. In this case, for example, the inspection unit 40 determines the presence or absence of a defect from a dark portion in an image captured with light L5 from the second illumination unit 25, in the same way as determining the presence or absence of a defect based on an image captured with light L3 from the first illumination unit 23. Even with this configuration, since the first straight line 23a and the second straight line 25a are non-parallel, a defect that was difficult to show in an image captured with the light L3 from the first illumination section 23 may be easily shown in an image captured with the light L5 from the second illumination section 25, and a defect that was difficult to show in an image captured with the light L5 from the second illumination section 25 may be easily shown in an image captured with the light L3 from the first illumination section 23. Therefore, such an inspection device can suppress a decrease in the detection accuracy of defects in the inspection object 60, compared to a case in which the illumination unit 21 does not have the second illumination section 25.

[0162] In the second and sixth embodiments, the second illumination section 25 is located upstream of the first illumination section 23 in the first transport direction D1. However, in the second and sixth embodiments, the position of the second illumination section 25 relative to the first illumination section 23 is not particularly limited, and the second illumination section 25 may be located downstream of the first illumination section 23 in the first transport direction D1. In this case, for example, in the second embodiment, the second illumination section 25 is arranged so that the second straight line 25a is inclined upward in the opposite direction to the first transport direction D1, and in the sixth embodiment, the second illumination section 25 is arranged so that the second straight line 25a is inclined downward in the opposite direction to the first transport direction D1. Note that the first straight line 23a may not be parallel to the vertical direction.

[0163] In the second and sixth embodiments, when the inspection object 60 is transported in the first transport direction D1, the first illumination section 23 and the second illumination section 25 may alternately irradiate the light L3 and L5 at a predetermined time interval, and the imaging unit 30 may alternately image the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 in synchronization with the irradiation of the light L3 and L5 from the first illumination section 23 and the second illumination section 25. Even in such a configuration, the imaging unit 30 can individually image the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25. Furthermore, the inspection object 60 is transported in only one direction. Therefore, the configuration of the transport device can be simplified compared to the case where the inspection object 60 is transported in multiple directions. Furthermore, the time required for the inspection device 1 to inspect the inspection object 60 for defects can be shortened.

[0164] In the third and seventh embodiments, the second imaging section 32 is described as capturing an image of the light L5 from the second illumination section 25 that passes through the object 60 when the object 60 is transported in the second transport direction D2. However, in the third and seventh embodiments, the second imaging section 32 may capture an image of the light L5 from the second illumination section 25 that passes through the object 60 when the object 60 is transported in the first transport direction D1. In this case, for example, the first illumination section 23 and the second illumination section 25 are separated from each other, and the first imaging section 31 and the second imaging section 32 are separated from each other so that the light L3 from the first illumination section 23 is unlikely to be incident on the second imaging section 32 and the light L5 from the second illumination section 25 is unlikely to be incident on the first imaging section 31. In this way, even if the illumination unit 21 simultaneously emits light L3 and L5 from the first illumination section 23 and the second illumination section 25, the imaging unit 30 can capture the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 individually. Furthermore, the inspection object 60 is transported only in one direction. Therefore, the configuration of the transport device can be simplified compared to the case where the inspection object 60 is transported in multiple directions. Furthermore, the time required for the inspection device 1 to inspect the inspection object 60 for defects can be shortened.

[0165] In the third and seventh embodiments, the second imaging unit 32 is described as being parallel to the optical axis of the second illumination unit 25 and does not intersect with the second straight line 25a passing through the light exit surface 25e of the second illumination unit 25. However, in the third embodiment, when the first straight line 23a and the second straight line 25a are non-parallel, the second imaging unit 32 may intersect with the second straight line 25a. In this case, for example, the inspection unit 40 determines the presence or absence of a defect from a dark portion in an image captured by the second imaging unit 32 using light L5 from the second illumination unit 25, in the same way as determining the presence or absence of a defect based on an image captured by the first imaging unit 31 using light L3 from the first illumination unit 23. Even with this configuration, since the first straight line 23a and the second straight line 25a are non-parallel, a defect that was difficult to show in an image captured with the light L3 from the first illumination section 23 may be easily shown in an image captured with the light L5 from the second illumination section 25, and a defect that was difficult to show in an image captured with the light L5 from the second illumination section 25 may be easily shown in an image captured with the light L3 from the first illumination section 23. Therefore, such an inspection device can suppress a decrease in the detection accuracy of defects in the inspection object 60, compared to a case in which the illumination unit 21 does not have the second illumination section 25.

[0166] In the third and seventh embodiments, the second illumination section 25 located downstream of the first illumination section 23 in the first conveying direction D1 and the second imaging section 32 located downstream of the first imaging section 31 in the first conveying direction D1 are described as examples. However, in the third and seventh embodiments, the positions of the first illumination section 23, the second illumination section 25, the first imaging section 31, and the second imaging section 32 in the direction parallel to the first conveying direction D1 are not particularly limited. For example, the second illumination section 25 may be disposed upstream of the first illumination section 23 in the first conveying direction D1. In addition, the second illumination section 25 may be disposed upstream of the first illumination section 23 in the first conveying direction D1, and the second imaging section 32 may be disposed upstream of the first imaging section 31 in the first conveying direction D1. In the third embodiment, the second illumination section 25 may be disposed such that the second straight line 25a is inclined upward in the opposite direction to the first conveying direction D1. In the seventh embodiment, the second illumination section 25 may be disposed such that the second straight line 25a is inclined downward in the opposite direction to the first conveying direction D1. From the viewpoint of suppressing the incidence of the light L5 from the second illumination section 25 on the first imaging section 31, it is preferable that the second straight line 25a is inclined from the second illumination section 25 toward the side where the imaging unit 30 is located, toward the opposite side to the first imaging section 31 side with the second illumination section 25 as a reference in the direction parallel to the first conveying direction D1, as in the third and seventh embodiments. From the viewpoint of miniaturization, it is preferable to dispose the second illumination section 25 such that the second straight line 25a passes between the first illumination section 23 and the first imaging section 31.

[0167] In the second, third, sixth and seventh embodiments, an example has been described in which the inspection device 1 captures the image of the light L3 from the first illumination section 23 and then captures the image of the light L5 from the second illumination section 25. However, in the third embodiment, the inspection device 1 may capture the image of the light L3 from the first illumination section 23 and then capture the image of the light L5 from the second illumination section 25.

[0168] In the third and seventh embodiments, when the inspection object 60 is transported in the first transport direction D1, the first illumination section 23 and the second illumination section 25 may alternately irradiate the light L3 and L5 at a predetermined time interval, the first imaging section 31 may capture the light L3 from the first illumination section 23 in synchronization with the irradiation of the light L3 from the first illumination section 23, and the second imaging section 32 may capture the light L5 from the second illumination section 25 in synchronization with the irradiation of the light L5 from the second illumination section 25. Even in such a configuration, the imaging unit 30 may capture the light L3 from the first illumination section 23 and the light L5 from the second illumination section 25 individually. Furthermore, the inspection object 60 is transported only in one direction. Therefore, the configuration of the transport device may be simplified compared to the case where the inspection object 60 is transported in multiple directions. Furthermore, the time required for the inspection device 1 to inspect the inspection object 60 for defects may be shortened.

[0169] In the first, fourth, fifth, eighth, and ninth embodiments, the illumination unit 21 is a single line illumination, and in the second, third, sixth, and seventh embodiments, the illumination unit 21 is a single line illumination having a first illumination section 23 and a second illumination section 25. In the ninth embodiment, the illumination unit 21 is a single line illumination. However, the illumination unit 21 and the other illumination unit 121 are not particularly limited. For example, the illumination unit 21 in the first, fourth, fifth, eighth, and ninth embodiments and the other illumination unit 121 in the ninth embodiment may be planar illumination in which LEDs are two-dimensionally arranged. In the second, third, sixth, and seventh embodiments, the first illumination section 23 and the second illumination section 25 may be planar illumination in which LEDs are two-dimensionally arranged.

[0170] In the first, second, fifth, sixth and ninth embodiments, the imaging unit 30 is described as an example of a line sensor camera, and in the third, fourth, seventh and eighth embodiments, the imaging unit 30 is described as an example of a line sensor camera having a first imaging section 31 and a second imaging section 32. In the ninth embodiment, the imaging unit 30 is described as an example of a line sensor camera. However, the imaging unit 30 and the other imaging unit 130 are not particularly limited. For example, the imaging unit 30 in the first, second, fifth, sixth and ninth embodiments and the other imaging unit 130 in the ninth embodiment may be an area sensor camera. In the third, fourth, seventh and eighth embodiments, the first imaging section 31 and the second imaging section 32 may be an area sensor camera.

[0171] In the above embodiment, the transport device 10 that moves the object 60 to be inspected relative to the illumination unit 21 and the imaging unit 30 has been described as an example. However, the transport device may be one that moves the illumination unit 21 and the imaging unit 30 relative to the object 60 to be inspected.

[0172] According to a first aspect of the present invention, an inspection device is provided that can suppress a decrease in the accuracy of detecting defects on the surface of an object to be inspected, and according to a second aspect of the present invention, an inspection device is provided that can suppress a narrowing of the inspection range for defects on the surface of an object to be inspected, and can be used in fields such as inspection devices for the surface of lighting fixtures.

Claims

1. an illumination unit including a convexly curved surface and a concavely curved surface opposite to the one surface, the illumination unit being translucent and disposed on the other surface side based on an object to be inspected used in a lighting fixture, and irradiating light onto the other surface; an imaging unit that is disposed on the one surface side of the inspection object based on the inspection object and captures an image of light from the illumination unit that passes through the inspection object; an inspection unit that determines the presence or absence of defects on the one surface and the other surface of the object to be inspected based on images captured by the imaging unit; a transparent support film that crosses between the illumination unit and the imaging unit and carries the object to be inspected; Equipped An inspection device characterized by:

2. the imaging unit includes a first imaging section that images light from the illumination unit, the first imaging section intersecting a straight line that is parallel to an optical axis of the illumination unit and passes through the light exit surface of the illumination unit, and that images the light from the illumination unit, the light passing through the object to be inspected, and a second imaging section that images the light from the illumination unit, the light not intersecting the straight line, and that passes through the object to be inspected; The inspection unit determines the presence or absence of the defect from a dark portion in an image captured by the first imaging unit, and determines the presence or absence of the defect from a bright portion in an image captured by the second imaging unit.

2. The inspection apparatus according to claim 1 .

3. an illumination unit including a convexly curved surface and a concavely curved surface opposite to the one surface, the illumination unit having translucency and being disposed on the one surface side based on an object to be inspected to be used in a lighting fixture, and irradiating light onto the one surface; an imaging unit that is disposed on the other surface side of the inspection object based on the inspection object and captures an image of light from the illumination unit that passes through the inspection object; an inspection unit that determines the presence or absence of defects on the one surface and the other surface of the object to be inspected based on images captured by the imaging unit; a transparent support film that crosses between the illumination unit and the imaging unit and carries the object to be inspected; Equipped An inspection device characterized by:

4. the imaging unit includes a first imaging section that images light from the illumination unit, the first imaging section intersecting a straight line that is parallel to an optical axis of the illumination unit and passes through the light exit surface of the illumination unit, and that images the light from the illumination unit, the light passing through the object to be inspected, and a second imaging section that images the light from the illumination unit, the light not intersecting the straight line, and that passes through the object to be inspected; The inspection unit determines the presence or absence of the defect from a dark portion in an image captured by the first imaging unit, and determines the presence or absence of the defect from a bright portion in an image captured by the second imaging unit.

4. The inspection apparatus according to claim 3.

5. Another illumination unit is disposed on the other surface side of the object to be inspected and irradiates the other surface with light; Another imaging unit is disposed on the one surface side of the inspection object based on the inspection object, and captures an image of light from the other illumination unit that passes through the inspection object; Further comprising: The inspection unit determines the presence or absence of the defect based on the image captured by the imaging unit and the image captured by the other imaging unit, the imaging unit intersects with a first straight line that is parallel to an optical axis of the lighting unit and passes through a light exit surface of the lighting unit; the other imaging unit intersects with a second straight line that is parallel to the optical axis of the other lighting unit and passes through the light exit surface of the other lighting unit; The first line and the second line do not intersect between the illumination unit and the imaging unit.

5. The inspection apparatus according to claim 3 or 4.

6. a light-transmitting rib protruding toward the other surface side is provided on an outer periphery of the object to be inspected, The test object is placed on the support film with the end of the rib abutting against the support film, The other surface and the one surface are spaced apart from the support film.

6. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

Images