JP2005345425A - Visual inspection device, and ultraviolet light lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a visual inspection device, and an ultraviolet light lighting system capable of irradiating ultraviolet light on a surface of an inspection target object such that there are no shadows thereon. <P>SOLUTION: An ultraviolet light component irradiated on a semi-transparent mirror 4 via a diffusion plate 3 is guided onto an optical path axis of an image capturing means 6 by a semi-transparent mirror 4 passing one portion of the ultraviolet light component and reflecting other portions. The ultraviolet light reflected by the semi-transparent mirror 4 into a conical surface reflector 5 along the optical path axis of the image capturing means 6 is reflected by the conical surface reflector 5 and irradiated on an outer circumferential surface of the inspection target object 1. The ultraviolet light reflected by the outer circumferential surface of the inspection target object 1 is reflected again by the conical surface reflector 6, and enters the semi-transparent mirror 4. On part of the ultraviolet light entering the semi-transparent mirror 4 passes through and it is guided to the image capturing means 6 in the same way as the ultraviolet light irradiated via the diffusion plate 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an appearance inspection apparatus and an ultraviolet illumination apparatus that inspects the surface of an inspection object using light in the ultraviolet region.

  As a method for inspecting defects appearing on the surface of an article, visual inspection has been mainly performed by an operator. However, the visual inspection is likely to cause variations by the inspector, and it is difficult to prevent even a small defect from being overlooked. For this reason, various techniques have been proposed that allow more accurate inspection.

  By the way, it is known that, depending on the inspection object, inspection using ultraviolet light rather than visible light emphasizes scratches and spots that have been overlooked in inspection using visible light, making inspection easier. Yes. For example, in Patent Document 1, regarding the technique of inspecting the surface of an inspection object using light in the ultraviolet region, the applied state of solder applied to an electrode is indicated by the contrast between the electrode and solder based on the reflectance of ultraviolet light. A technique for inspecting with emphasis is disclosed. According to such a technique, an abnormal part can be emphasized, so that an accurate inspection can be performed.

JP 2003-332730 A

  However, in the ultraviolet light source described in Patent Document 1, the ultraviolet light LED (Light Emitting Diode), which is a point light source, is arranged in a ring shape in plan view, and irradiates ultraviolet light from a predetermined oblique angle. There is a possibility that ultraviolet light is not uniformly irradiated.

  Here, it is preferable to bend the light from the light source so that the optical path of the light that irradiates the surface of the object to be inspected and the optical path that enters the image capturing means are coaxial, or a surface light source is used as the light source. Since ultraviolet light has a large attenuation amount, it has been difficult to obtain ultraviolet light having sufficient intensity.

  The present invention has been proposed in view of such a conventional situation, and an ultraviolet ray having sufficient intensity even if the optical path of the light irradiating the surface of the inspection object and the optical path incident on the image capturing means are coaxial. An object of the present invention is to provide an appearance inspection apparatus and an ultraviolet light illumination apparatus capable of obtaining light.

  In order to solve the above-described problems, an appearance inspection apparatus according to the present invention is an appearance inspection apparatus for inspecting at least a part of the outer peripheral surface of an inspection object, and at least the part of the outer periphery surface of the inspection object is at least ultraviolet. An ultraviolet light illuminating means for illuminating with light, a frustoconical side surface-shaped reflecting surface on the inner surface side, a conical surface reflecting mirror having a large-diameter opening and a small-diameter opening, and the conical reflecting mirror The outer peripheral surface of the inspection object arranged at the inspection position has an image capturing means for capturing an image projected on the conical reflecting mirror as an image, and the ultraviolet illumination means irradiates light including ultraviolet light. A light source for diffusing, an ultraviolet light diffusing means for diffusing at least ultraviolet light of the light emitted from the light source, and a semi-transparent mirror that transmits a part of the ultraviolet light component and reflects the other part, the ultraviolet light from the light source The reflected or transmitted light of the light component is Irradiating the conical surface shape reflector, the transmitted or reflected light of the ultraviolet light component from the circular conical surface shape reflector is characterized by comprising a beam splitter for irradiating the image capturing means.

  An appearance inspection apparatus according to the present invention is an appearance inspection apparatus for inspecting at least a part of a surface of an inspection object, and is an ultraviolet light illumination for illuminating the part of the inspection object with at least ultraviolet light. Means and image capturing means for capturing an image of the surface of the inspection object as an image, and the ultraviolet light illuminating means includes a light source for irradiating light including ultraviolet light, and at least of light emitted from the light source. An ultraviolet light diffusing means that transmits while diffusing ultraviolet light, and a semi-transparent mirror that transmits a part of the ultraviolet light component and reflects the other part, the reflected light or transmitted light of the ultraviolet light component from the light source It has a beam splitter that irradiates the surface of the inspection object and irradiates the image capturing means with the transmitted light or reflected light of the ultraviolet light component from the surface of the inspection object.

  The ultraviolet illumination device according to the present invention includes a light source that irradiates light including ultraviolet light, an ultraviolet light diffusing means that diffuses and transmits at least ultraviolet light emitted from the light source, and an ultraviolet light component. A semi-transparent mirror that transmits a part and reflects the other part, irradiating the reflected light or transmitted light of the ultraviolet light component from the light source to the illumination target position, and transmitting the ultraviolet light component from the illumination target position Or it has the beam splitter which irradiates an image capturing means with reflected light.

  Here, it is preferable that a quartz diffusion plate is used for the ultraviolet light diffusion means, and a beam splitter in which a partial reflection film is formed on the quartz plate is used for the semi-transparent mirror.

  Further, an ultraviolet lens is preferably used as the lens of the image capturing means.

  An appearance inspection apparatus and an ultraviolet illumination apparatus according to the present invention include an ultraviolet light diffusing unit that diffuses ultraviolet light emitted from a light source, and a semi-transparent mirror that transmits a part of the ultraviolet light component and reflects the other part. Thereby, the ultraviolet light required for the inspection of the inspection object can be obtained.

  Here, a quartz diffusion plate is used for the ultraviolet light diffusing means, and absorption of ultraviolet light can be prevented by using a beam splitter having a partially reflective film formed on the quartz plate for the semi-transparent mirror.

  Further, by using an ultraviolet lens as the lens of the image capturing means, it is possible to image ultraviolet light with high sensitivity.

  Hereinafter, specific embodiments to which the present invention is applied will be described. An appearance inspection apparatus and an ultraviolet light illumination apparatus shown as specific examples of the present invention are such that an optical path for irradiating ultraviolet light onto the surface of an inspection object coincides with an optical path incident on a UV (Ultraviolet) camera. .

(Embodiment 1)
FIG. 1 is a block diagram illustrating a configuration of an appearance inspection apparatus 10 according to the first embodiment. This appearance inspection apparatus 10 inspects at least a part of the outer peripheral surface of an inspection object 1 having a cylindrical shape or a columnar shape. The inspection object 1 is not limited to a cylindrical shape or a columnar shape, but may be a combination of a plurality of cylindrical shapes having different diameters, or a combination of a cylindrical shape and other shapes, and more or less complete. A shape such as a polygonal column that can be identified with a column or the like for inspection is also included even if it is not a cylindrical shape or a columnar shape.

  An appearance inspection apparatus 10 shown in FIG. 1 has an ultraviolet light source 2 that irradiates the surface of an inspection object 1 with light including ultraviolet light, and a diffusion that transmits ultraviolet light emitted from the ultraviolet light source 2 while diffusing it. A conical surface having a large-diameter opening and a small-diameter opening; a plate 3; a semi-transparent mirror 4 that transmits a part of the ultraviolet light component and reflects the other part; -Shaped reflecting mirror 5, image capturing means 6 having a UV camera for capturing an image of the outer peripheral surface of inspection object 1 projected on conical reflecting mirror 5, and image processing means 7 for processing the captured image And an image display device 8 for displaying an image.

  The ultraviolet light source 2 is configured, for example, by arranging a plurality of ultraviolet light LEDs (Light Emitting Diodes) in a planar shape. This LED for ultraviolet light emits light in the ultraviolet light region having a wavelength of 200 to 400 nm.

  The diffusing plate 3 diffuses light and uses the point light source of the ultraviolet light source 2 as a surface light source. This diffusing plate 3 is a sand surface on one side of the substrate with an abrasive. For the substrate, it is desirable to use synthetic quartz having excellent transparency in the wavelength region of 200 nm to 2 μm in order to transmit while diffusing without absorbing ultraviolet light.

  The semi-transparent mirror 4 is composed of a beam splitter that transmits a part of the ultraviolet light component and reflects the other part. The beam splitter reflects the ultraviolet light emitted from the ultraviolet light source 2 and irradiates the conical reflecting mirror 5 and transmits the ultraviolet light reflected by the conical reflecting mirror 5 to the image capturing means. Irradiate. FIG. 2 is an enlarged schematic view of a part of the beam splitter. In this beam splitter, a plurality of fine reflecting films 4a are deposited on a quartz substrate 4b at a predetermined interval. In addition, it is desirable that the beam splitter reflects 50% of the incident light by the reflective film 4a and transmits the remaining 50% by the portion not provided with the reflective film 4a. As such a beam splitter, for example, a polka dot beam splitter (trade name) manufactured by Edmund Industrial Optics may be used. This polka dot beam splitter is obtained by vacuum-depositing a 0.1 × 0.1 mm square reflection-enhanced aluminum film on a synthetic quartz substrate at a center to center of 0.15 mm.

  The conical reflecting mirror 5 has a frustoconical side surface-shaped reflecting surface on the inner surface side, and has a large-diameter opening and a small-diameter opening. The conical reflecting mirror 5 reflects ultraviolet light at the reflecting surface and irradiates the outer peripheral surface of the inspection object 1, and reflects the ultraviolet light reflected at the outer peripheral surface at the reflecting surface. The angle θ of the reflecting surface of the conical reflecting mirror 5 is set to 45 °.

  The image capturing means 6 has a UV camera and is arranged so as to capture the outer peripheral surface of the inspection object 1 projected on the conical reflecting mirror 5. As the lens 6a of the UV camera, an ultraviolet lens made of quartz is used so that ultraviolet light is not absorbed. The UV camera is a CCD (Charge Coupled Device) camera having sensitivity in the ultraviolet region. As this UV camera, for example, a CCD element surface is coated with a fluorescent agent that converts ultraviolet light into visible light, or the inner surface of the CCD drive structure is physically shaved so that the ultraviolet light is directly incident on the photoelectric conversion unit. There is something.

  Here, an image captured by the image capturing means 6 will be described with reference to FIG. As shown in FIG. 3, a cylindrical inspection object 1 is mechanically inserted in the Z-axis direction into a conical reflecting mirror 5 having an inclination of 45 ° from the horizontal, and the inspection object is inserted into the conical reflecting mirror 5. An image on which the outer peripheral surface of the object 1 is projected is picked up by the image capturing means 6. Therefore, the image capturing means 6 captures the ring-shaped image projected on the conical reflecting mirror 5 and the image of the top surface of the inspection object 1. In the ring-shaped image, the outer peripheral surface from the bottom surface to the top surface direction of the inspection object 1 is projected from the small diameter toward the large diameter direction.

  The image processing means 7 is composed of, for example, a personal computer capable of storing and calculating. Since the image of the outer peripheral surface of the inspection object 1 captured by the image capturing means 6 is ring-shaped and is deformed compared to the image when the inspection object 1 is observed from the side, the image processing means 7 Image processing is performed, and the outer peripheral surface of the inspection object 1 is converted into an image showing a developed state and displayed on the image display device 8. The area of the defect shown on the display image is proportional to the area of the actual defect, and the defect is evaluated by the image processing means 7. Further, it is desirable that the image processing means 7 has a correcting means for correcting the insertion position of the inspection object 1 when it is shifted in the xy direction.

  Next, the optical path of the appearance inspection apparatus 10 will be described. The ultraviolet light from the ultraviolet light source 2 provided so as to be perpendicular to the optical path to the image capturing means 6 is scattered by the diffusion plate 3 to become a surface light source, and ultraviolet light is emitted from the entire diffusion plate 3. . Then, the entire surface of the inspection object 1 is uniformly irradiated with ultraviolet light.

  The optical path of the ultraviolet light irradiated through the diffusing plate 3 is changed by the semi-transparent mirror 4 provided on the optical path to the image capturing means 6. The semi-transparent mirror 4 is installed so that the angle with respect to the optical path to the image capturing means 6 and the optical path of the ultraviolet light irradiated through the diffusion plate 3 is 45 °. Therefore, the ultraviolet light component irradiated to the semi-transparent mirror 4 via the diffusion plate 3 is partially guided by the other part of the semi-transparent mirror 4 and reflected on the optical path axis of the image capturing means 6.

  The ultraviolet light reflected from the semi-transparent mirror 4 and incident on the conical reflecting mirror 5 along the optical path axis of the image capturing means 6 is reflected by the conical reflecting mirror 5 and irradiates the outer peripheral surface of the inspection object 1. . Since the angle of the reflecting surface of the conical reflecting mirror 5 is 45 °, the outer peripheral surface of the inspection object 1 is irradiated with ultraviolet light at a right angle, and the incident light of the ultraviolet light on the surface and the reflected light are coaxial. .

  The ultraviolet light reflected on the outer peripheral surface of the inspection object 1 is reflected again by the conical reflecting mirror 6 and enters the semi-transparent mirror 4. Similar to the ultraviolet light irradiated through the diffusion plate 3, the semi-transparent mirror 4 transmits a part thereof to the image capturing means 6 and reflects the other part. Therefore, for example, if a beam splitter that reflects 50% of incident light on the semi-transparent mirror 4 and transmits the remaining 50% is used, the ultraviolet light incident on the image capturing means 6 is irradiated through the diffusion plate 3. It is 25% stronger than the ultraviolet light.

  In this way, the semi-transparent mirror 4 that transmits a part of the ultraviolet light component and reflects the other part is provided on the optical path of the image capturing means 6, and the optical path of the emitted ultraviolet light and the optical path incident on the image capturing means 6 Can be irradiated uniformly with ultraviolet light. Moreover, the outer peripheral surface of the inspection object 1 can be imaged over the entire circumference by projecting the outer peripheral surface of the inspection object 1 onto the conical reflecting mirror 5 and capturing an image.

  In the configuration of the outer periphery inspection apparatus 10 in FIG. 1, the image capturing means 6 captures the ultraviolet light transmitted through the semi-transparent mirror 4 among the ultraviolet light reflected on the outer peripheral surface of the inspection object 1. Not limited to this, the ultraviolet light reflected by the semi-transparent mirror 4 may be taken in. In this case, the image capturing means 6 is disposed so that the ultraviolet light semi-emitted by the semi-transparent mirror 4 can be captured, and the ultraviolet light source is disposed so that the ultraviolet light is transmitted through the semi-transparent mirror 4.

(Embodiment 2)
FIG. 2 is a block diagram illustrating a configuration of the appearance inspection apparatus 20 according to the second embodiment. This appearance inspection apparatus 20 inspects the surface of a planar inspection object 21.

  The appearance inspection apparatus 20 includes an ultraviolet light source 2 that irradiates the surface of the inspection object 21 with light including ultraviolet light, a diffusion plate 3 that transmits while diffusing the ultraviolet light emitted from the ultraviolet light source 2, and Semi-transparent mirror 4 that transmits a part of the ultraviolet light component and reflects the other part, image capturing means 6 having a UV camera for capturing an image of the surface of the inspection object 21, and an image for processing the captured image The processing unit 7 and an image display device 8 for displaying an image are included. In addition, the same instruction | indication code | symbol is attached | subjected to the part corresponding to each part of the structure of the external appearance inspection apparatus 10 shown in FIG. 1 mentioned above. That is, this appearance inspection apparatus 20 has a conical side reflecting surface on the inner surface side from the configuration of the appearance inspection apparatus 10 shown in FIG. 1, and a conical reflecting mirror 5 having a large diameter opening and a small diameter opening. Is excluded.

  Here, the optical path of the appearance inspection apparatus 20 will be described. Ultraviolet light from the ultraviolet light source 2 provided so as to be perpendicular to the optical path to the image capturing means 6 is scattered by the diffusion plate 3, and ultraviolet light is emitted from the entire diffusion plate 3. Then, the entire surface of the inspection object 21 is uniformly irradiated with ultraviolet light.

  The optical path of the ultraviolet light irradiated through the diffusing plate 3 is changed by the semi-transparent mirror 4 provided on the optical path to the image capturing means 6. The semi-transparent mirror 4 is installed so that the angle with respect to the optical path to the image capturing means 6 and the optical path of the ultraviolet light irradiated through the diffusion plate 3 is 45 °. Therefore, the ultraviolet light component irradiated to the semi-transparent mirror 4 through the diffusion plate 3 is partially transmitted but reflected on the other part and guided to the optical path axis of the image capturing means 6.

  The ultraviolet light reflected from the semi-transparent mirror 4 and incident along the optical path axis of the image capturing means 6 is irradiated at a right angle to the surface of the inspection object 21, and the incident light of the ultraviolet light on the surface and the reflected light are coaxial. It becomes.

  The ultraviolet light reflected on the surface of the inspection object 21 is incident on the semi-transparent mirror 4 again. The semi-transparent mirror 4 is partially transmitted and guided to the image capturing means 6 as in the case of the ultraviolet light irradiated through the diffusion plate 3, and the other part is reflected. Therefore, for example, if a beam splitter that reflects 50% of incident light on the semi-transparent mirror 4 and transmits the remaining 50% is used, the ultraviolet light incident on the image capturing means 6 is irradiated through the diffusion plate 3. It is 25% stronger than the ultraviolet light.

  In this way, the semi-transparent mirror 4 that transmits a part of the ultraviolet light component and reflects the other part is provided on the optical path of the image capturing means 6, and the optical path of the emitted ultraviolet light and the optical path incident on the image capturing means 6 Can be irradiated uniformly with ultraviolet light. Further, the image captured by the image capturing means 6 is similar to the image that is actually viewed without performing image processing, and therefore it is easy to grasp defects and abnormalities.

(Embodiment 3)
FIG. 5 is a block diagram illustrating a configuration of the appearance inspection apparatus 30 according to the third embodiment. In addition, the same instruction | indication code | symbol is attached | subjected to the part corresponding to each part of the structure shown in FIG. The inspection object 31 may be composed of only a cylindrical shape or a columnar shape, may be a combination of a plurality of cylindrical shapes having different diameters, or may be a combination of a cylindrical shape and other shapes, and may be a substantially complete cylindrical shape or a cylindrical shape. A shape such as a polygonal column that can be identified with a cylinder or the like for inspection is also included even if it is not a shape. Collectively, these articles are hereinafter referred to as “cylindrical objects”.

  The visual inspection apparatus 30 shown in FIG. 5 has sensitivity in an ultraviolet light source 2 for illuminating a cylindrical object that is an inspection object 31 and an ultraviolet light region for capturing an image of the outer periphery of the side surface of the cylindrical object. And an image capturing means 6 having a UV camera. The ultraviolet light from the ultraviolet light source 2 provided on the side surface with respect to the optical path to the image capturing means 6 is scattered by the diffusion plate 3 and the path is changed by the semi-transparent mirror 4 provided in front of the image capturing means 6. And incident along the axis of the image capturing means 6. The ultraviolet light in this embodiment is re-routed by the reflecting mirror 33 provided below the conical reflecting mirror 32 and is incident on the conical reflecting mirror 32. The angle θ of the reflecting surface of the conical reflecting mirror 32 is 45 °. A central hole is formed in the central portion of the conical reflector 32, and a cylindrical object as the inspection object 31 is introduced through the central hole. The illumination light is reflected by the reflecting surface of the conical reflecting mirror 32 and irradiates the cylindrical object. The reflected light reflected from the outer periphery of the side surface of the cylindrical object is reflected by the reflecting surface of the conical reflecting mirror 32, is rerouted by the reflecting mirror 33, passes through the semi-transparent mirror 4, and reaches the image capturing means 6. To do. The image capturing means 6 is arranged so as to capture an image reflected on the conical reflecting mirror 32. In this way, the outer periphery of the side surface of the cylindrical object is imaged on the conical reflecting mirror 32, thereby imaging the side surface of the cylindrical object over the entire circumference without rotating the cylindrical object or the image capturing means 6. can do.

  Here, the distance between the conical reflecting mirror 32 and the reflecting mirror 33 is configured according to the length of the cylindrical object that is the inspection object 31. This is because when the distance between the conical reflecting mirror 32 and the reflecting mirror 33 is not appropriate, the cylindrical object itself blocks the ultraviolet light and the image, so that the side surface of the cylindrical object cannot be completely projected. In this way, by configuring according to the length of the cylindrical object that is the inspection object 31, it can be applied to inspection objects of various lengths.

  FIG. 6 shows the reflecting mirror 33, where (a) is a cross-sectional view, and (b) and (c) are views seen from the inspection object passing direction side (mirror surface) and the opposite side (back surface), respectively. . As shown in FIG. 6, the reflecting mirror 33 has a hole through which the inspection object 31 passes, and the hole is formed by drilling from the inspection object passage direction and the camera imaging direction. That is, the side surface of the through-hole 33a of the reflecting mirror 33 that is installed at an angle of 45 ° is not visible from the imaging direction of the camera and from the inspection object passage direction. The side surface of the through hole 33a is treated with a matte black paint or the like to prevent irregular reflection. In this way, by using the reflecting mirror 33 provided with a passage hole so that light is not reflected, the image capturing means 6 is obtained without irregularly reflecting the image of the outer periphery of the side surface of the cylindrical object projected on the conical reflecting mirror 32. Can be sent to.

  However, the image of the outer periphery of the cylindrical object projected on the mirror surface 33b of FIG. 6B and captured by the image capturing means 6 is a ring shape, which is deformed compared to the image when the cylindrical object is observed from the side surface. It is difficult to perform inspection even if it is displayed as it is. Therefore, image processing is performed by the image processing means 7, and the image is converted into an image showing a developed state of the outer periphery of the side surface of the cylindrical object and displayed on the image display device 8. By displaying in this way, the displayed image is similar to that obtained by observing a cylindrical object from the side, and what is inspected is easy to find defects and abnormalities, and the position and size of the defects. This can be grasped immediately visually or quantitatively. The area of the defect shown on the display image is proportional to the area of the actual defect, and the defect can be evaluated by image processing.

  As described above, when the central axis of the cylindrical object and the central axis of the conical reflecting mirror 32 coincide with each other, the image captured by the image capturing means 6 is changed to an image showing a state in which the outer periphery of the side surface of the cylindrical object is developed. The conversion is performed accurately, but when it is tilted, the conversion is not performed accurately, and the image is displayed in a deformed form. Therefore, in reality, even if it is a straight line, it appears as a curve, and what is inspected cannot be distinguished whether it is a deformation of the screen due to an inclination or an abnormality caused by a deformation of a cylindrical object that is an inspection object. .

In order to solve this problem, it is preferable to provide correction means for preventing the display image from being deformed by tilt. This correction means includes a guide member 34 that guides the position of the conical reflector 32 while correcting the posture of the cylindrical object that is the inspection object 31, and the cylindrical object that is the inspection object inside the guide member 34. And a sensor 35 for detecting that has passed.
By this correcting means, the cylindrical object thrown in from the introduction part of the guide member 34 is adjusted in its posture while proceeding downward through the introduction part. The center axis of the mirror 32 is in agreement. Therefore, the image captured through the conical reflecting mirror 32 is accurately converted and displayed on the image display device 8 as an image showing a state in which the outer periphery of the side surface of the cylindrical object is developed. After the imaging, the cylindrical object passes through the through-hole 33a in which irregular reflection at the center of the reflecting mirror 33 is prevented, and is collected by the conveying means 36 (a container, a conveyor, or the like).

  As described above, in the present embodiment, it is possible to continuously inspect the appearance by simply inserting and dropping the cylindrical object that is the inspection object 31.

  In this embodiment, the outer peripheral surface is inspected in a state where the cylindrical object as the inspection object 31 is thrown in and dropped, but the apparatus is configured horizontally and passes through the cylindrical object in the horizontal direction. By doing so, it is possible to continuously inspect the appearance.

(Embodiment 4)
Next, an appearance inspection apparatus 40 according to the fourth embodiment will be described with reference to the drawings. In the embodiment described below, a coil bobbin, a screw, or the like is illustrated as the inspection object 41, but is not limited to this, and a combination of a plurality of cylindrical shapes having different diameters or a cylindrical shape and the others Further, it may include a shape such as a polygonal column that can be identified with a column or the like for inspection even if it is not substantially perfect cylindrical or columnar.

  FIG. 7 is a block diagram showing a configuration of the appearance inspection apparatus 40. In addition, the same instruction | indication code | symbol is attached | subjected to the part corresponding to each part of the structure shown in FIG.

  The appearance inspection apparatus 40 shown in FIG. 7 is an apparatus for inspecting at least a part of the outer peripheral surface of an inspection object 41 having at least a part of a cylindrical shape or a shape approximated to a cylindrical shape, for example, winding a coil of an electronic component. It is used to inspect flaws and defects on bobbin flanges and screw heads (top and outer 360 °). In the specific example of FIG. 7, a coil bobbin is illustrated as the inspection object 41.

  The appearance inspection apparatus 40 includes a conical reflecting mirror 42, an ultraviolet light source 2, a semi-transparent mirror 4, an annular illumination unit 46, an image capturing unit 6, and an image processing unit 7. . The conical reflecting mirror 42 has a frustoconical side surface-shaped reflecting surface 43 on the inner surface side, and has a large-diameter opening 44 and a small-diameter opening 45.

  The conical surface serving as the reflecting surface 43 of the conical reflecting mirror 42 in the present embodiment has an inclination greater than 45 ° with respect to a plane orthogonal to the central axis of the cone, preferably 60 ° or more. By inclining, more preferably 75 °, a part of the outer peripheral surface (for example, the outer peripheral surface of the flange portion of the coil bobbin) is inspected without inserting the inspection object 41 into the conical reflecting mirror 42. It is configured as possible. That is, the inspection object 41 (for example, a coil bobbin) is simply transported by the transport means 47 to the external inspection position on the small-diameter opening 45 side of the conical reflector 42, and the image capturing means 6 as described later, An image of a partial outer peripheral surface of the inspection object 41 (for example, the outer peripheral surface of the flange portion of the coil bobbin) projected on the reflecting surface 43 of the conical reflecting mirror 42 can be captured as an image.

  Thus, by inspecting and imaging the partial outer peripheral surface of the inspection object 41 on the reflection surface 43 of the conical reflector 42, the inspection object 41 and the image capturing means 6 are not rotated and the inspection object 41 is rotated. In addition to being able to capture an image of a part of the outer peripheral surface, the outer peripheral inspection can be performed without inserting the inspection object 41 into the conical reflecting mirror 42.

  Here, the image of the partial outer peripheral surface of the inspection object 41 (for example, the outer peripheral surface of the flange portion of the coil bobbin) captured by the image capturing means 6 having a UV camera is ring-shaped, and the inspection object 41 is observed from the side surface. The image is deformed compared to the case image, and it is difficult to perform inspection even if it is displayed as it is. Therefore, the image captured by the image capturing means 6 is sent to an image processing means 7 that can be stored and operated, such as a computer, for image processing, so that, for example, the outer peripheral surface of the inspection object 41 is flattened into a rectangular shape. The displayed image is displayed on the image display device 8. By displaying in this way, the displayed image is similar to that obtained by observing the inspection object 41 from the side, and the object to be inspected can easily find defects and abnormalities, and the position of the defect The size can be immediately grasped visually or quantitatively. The area of the defect shown on the display image is proportional to the area of the actual defect, and the defect can be evaluated by image processing. In the present embodiment, the top surface (upper surface) of the inspection object 41 is also simultaneously captured by the image capturing means 6 and displayed as it is.

  The ultraviolet light source 2 irradiates light to the semi-transparent mirror 4 arranged on the optical path between the large-diameter opening 44 of the conical reflector 42 and the image capturing means 6 so as to emit light to the inspection object 41 side. The object to be inspected 41 is illuminated by reflection. In the illumination of the ultraviolet light source 2 through the semi-transparent mirror 4, in consideration of the fact that the top surface (upper surface) of the inspection object 41 is mainly illuminated and the side surfaces are not sufficiently illuminated, an annular shape including light in the ultraviolet light region is included. Illumination means 46 is provided, and the annular illumination means 46 illuminates a part of the outer peripheral surface of the inspection object 41 (for example, the outer peripheral surface of the flange portion of the coil bobbin) by irradiating light.

  The annular illuminating means 46 includes a plurality of light emitting means arranged in an annular shape for ultraviolet light LEDs, and an inspection object 41 arranged at an inspection position by introducing light from the plurality of ultraviolet light LEDs. An annular light guide member that emits light to a part of the outer peripheral surface is provided. The light guide member is formed in an annular shape surrounding the outer periphery of the conical reflecting mirror 42, and is configured using a light diffusion material that diffuses and emits incident light.

  As described above, when only the ultraviolet light source 2 is used for illumination, even if a surface light source is used, the illumination of the side surface of the inspection object 41 is insufficient only by the illumination with the light reflected from the ultraviolet light source 2 by the semi-transparent mirror 4. Further, supplementation of the luminance distribution is required, but supplementing the luminance distribution is not necessary by using the annular illumination means 46 as described above. Further, the appearance inspection apparatuses 10, 20, and 30 in the above-described embodiments are configured such that the optical path that irradiates the ultraviolet light onto the surfaces of the inspection objects 1, 21, and 31 and the optical path that is incident on the UV camera coincide with each other. However, according to the appearance inspection apparatus 40 of the present embodiment, the annular illumination means 46 is provided on the surface even if the optical path irradiated with ultraviolet light is different from the optical path incident on the UV camera. It is possible to reduce the shadows that occur and perform a highly accurate inspection.

  Next, the principle of the present embodiment will be described with reference to FIG. In the present embodiment, the conical surface serving as the reflecting surface 43 of the conical reflecting mirror 42 has an inclination greater than 45 ° with respect to a plane (horizontal plane) orthogonal to the central axis of the cone, Has an inclination of 60 ° or more, more preferably an inclination of 75 °. Thereby, even if the test object 41 is not inserted into the conical reflecting mirror 42, a part of the outer peripheral surface (for example, the outer peripheral surface of the flange portion of the coil bobbin) can be inspected.

  FIG. 8 schematically shows an optical path when performing a flange inspection of a bobbin around which a coil of an electronic component is wound, for example, as a specific example of the appearance inspection apparatus 40 of the present embodiment. In FIG. 8, the inspection object 41, for example, a coil bobbin is mechanically arranged vertically at an inspection position outside the conical reflecting mirror 42 on the small diameter opening 45 side, and the image capturing means 6, for example, one The outer periphery of the coil bobbin is photographed using the UV camera, and image processing is performed by the image processing means 7 connected to the UV camera to inspect the outer periphery of the side surface of the coil bobbin that is the inspection object 41, for example. In this embodiment, the side surface 41s and the top surface (upper surface) 41t of the coil bobbin can be inspected. In this case, the axis of the inspection object 41 (for example, a coil bobbin) is vertical (parallel to the central axis of the conical reflector 42), and the center of the inspection object 41 is positioned on the central axis of the conical reflector 42. Ideally.

  As the conveying means 47 for conveying the inspection object in the production line or the like, for example, a coil bobbin which is the inspection object 41 may be conveyed to an inspection position outside the small-diameter opening 45 side of the conical reflecting mirror 42. Since there is no need to insert it into the inside of the mirror 42, it is possible to use the transport means 47 having a relatively simple structure that can be transported on a horizontal plane.

  The reflecting surface 43 of the conical reflecting mirror 42 shown in FIG. 9 has an inclination of 75 ° with respect to a plane orthogonal to the central axis, and the lower side of the conical reflecting mirror 42 (the small diameter opening side). ) Shows a conceptual diagram in the case where, for example, a coil bobbin which is the inspection object 41 is arranged and the top surface 41t of the coil bobbin and the side surface 41s of the flange are simultaneously inspected. In the example of FIG. 9, the coil bobbin is disposed at the inspection position on the central axis of the conical reflector 42, and the lowest ridgeline of the side surface 41s of the flange of the coil bobbin 2 having the height h is the conical reflector. The state mapped to the lowermost part of the reflecting surface 43 of the mirror 42 is shown. The side surface 41s of the flange of the coil bobbin becomes a ring-shaped map having a width of h / 2 as shown by a gray portion in the top view of FIG.

  According to the present embodiment, as described above, by setting the inclination of the reflecting surface 43 of the conical reflecting mirror 42 to 45 ° or more, preferably 60 ° or more (more preferably 75 °), the inspection object is set. In a state where the object 41 is located outside the small-diameter opening 45 side of the conical reflector 42, the outer peripheral surface of the inspection object 41 (for example, the side surface of the screw head) is the reflecting surface 43 of the conical reflector 42. The image can be captured by the image capturing means 6. As a result, the conveying means 47 for the inspection object 41 only needs to be moved on a plane passing the inspection position outside the conical reflector 42, and not only can the structure be simplified, but also the vertical alignment of the axes. It is easy to improve the accuracy of the center and the center positioning accuracy. Further, when the inclination of the reflecting surface 43 of the conical reflecting mirror 42 is set to 75 °, the image capturing means 6 causes the ring shape having a width just half of the width of a part of the outer peripheral side surface of the inspection object 41. Therefore, there is an advantage that the burden of image processing calculation is reduced.

It is a block diagram which shows the structure of the external appearance inspection apparatus which concerns on embodiment of this invention. It is a figure for demonstrating a semi-transparent mirror. It is a figure for demonstrating the image taken in by an image taking means. It is a block diagram which shows the structure of the external appearance inspection apparatus which concerns on embodiment of this invention. It is a block diagram which shows the structure of the external appearance inspection apparatus which concerns on embodiment of this invention. It is a figure explaining a reflective mirror. It is a block diagram which shows the structure of the external appearance inspection apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the optical path of the external appearance inspection apparatus which concerns on embodiment of this invention. It is a figure explaining the image in case the center of a test subject and the center of a cone-shaped reflective mirror correspond.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inspection object, 2 Ultraviolet light source, 3 Diffuser plate, 4 Semi-transparent mirror, 5 Conical surface reflection mirror, 6 Image capture means, 7 Image processing means, 8 Image display apparatus, 10 Appearance inspection apparatus, 20 Appearance inspection apparatus, DESCRIPTION OF SYMBOLS 21 Inspection object, 30 Appearance inspection apparatus, 31 Inspection object, 32 Conical surface-shaped reflective mirror, 33 Reflection mirror, 34 Guide member, 35 Sensor part, 36 Conveying means, 40 Appearance inspection apparatus, 41 Inspection object, 42 Cone Planar reflector, 43 reflecting surface, 44 large-diameter opening, 45 small-diameter opening, 46 annular illumination means, 47 transport means

Claims (10)

An appearance inspection apparatus for inspecting at least a part of the outer peripheral surface of an inspection object,
Ultraviolet light illuminating means for illuminating the partial outer peripheral surface of the inspection object with at least ultraviolet light;
A conical reflecting mirror having a frustoconical side surface reflecting surface on the inner surface side and having a large-diameter opening and a small-diameter opening;
Image capturing means for capturing, as an image, an image of the outer peripheral surface of the inspection object arranged at the inspection position of the conical reflector, projected on the conical reflector,
The ultraviolet light illumination means includes:
A light source that emits light including ultraviolet light;
Ultraviolet light diffusing means that transmits while diffusing at least ultraviolet light emitted from the light source;
A semi-transparent mirror that transmits a part of the ultraviolet light component and reflects the other part, and irradiates the conical reflector with the reflected or transmitted light of the ultraviolet light component from the light source, thereby reflecting the conical reflection An appearance inspection apparatus comprising: a beam splitter for irradiating the image capturing means with transmitted light or reflected light of an ultraviolet light component from a mirror.   2. An appearance inspection apparatus according to claim 1, wherein a quartz diffusing plate is used for the ultraviolet light diffusing means, and a semi-transparent mirror having a partially reflecting film formed on the quartz plate is used for the beam splitter.   2. The appearance inspection apparatus according to claim 1, wherein the image capturing means includes an ultraviolet lens and has sensitivity in an ultraviolet light region.   2. An optical path changing reflecting mirror provided on the large-diameter opening side of the conical reflecting mirror and changing an optical path of reflected light from the conical reflecting mirror to the image capturing means. Appearance inspection apparatus as described.   5. The appearance inspection apparatus according to claim 4, wherein a through-hole is provided in the center of the optical path changing reflecting mirror for allowing an inspection object that has been inspected to pass therethrough.   The conical surface serving as the reflective surface of the conical reflector has an inclination of 45 ° with respect to a plane perpendicular to the central axis of the cone, and the inspection position is on the central axis of the conical reflector. The appearance inspection apparatus according to claim 1.   The conical surface, which is the reflecting surface of the conical reflector, has an inclination of 60 ° or more with respect to a plane orthogonal to the central axis of the cone, and the outside of the conical reflector on the small-diameter opening side. The appearance inspection apparatus according to claim 1, wherein the inspection position is an inspection position. An appearance inspection apparatus for inspecting at least a part of a surface of an inspection object,
Ultraviolet light illumination means for illuminating the partial surface of the inspection object with at least ultraviolet light;
Image capturing means for capturing an image of the surface of the inspection object as an image,
The ultraviolet light illumination means includes:
A light source that emits light including ultraviolet light;
Ultraviolet light diffusing means for diffusing at least ultraviolet light of the light emitted from this light source,
A semi-transparent mirror that transmits a part of the ultraviolet light component and reflects the other part, irradiating the surface of the inspection object with reflected or transmitted light of the ultraviolet light component from the light source, An appearance inspection apparatus comprising: a beam splitter that irradiates the image capturing means with transmitted light or reflected light of an ultraviolet light component from the surface. A light source that emits light including ultraviolet light;
Ultraviolet light diffusing means that transmits while diffusing at least ultraviolet light emitted from the light source;
A semi-transparent mirror that transmits a part of the ultraviolet light component and reflects the other part, and irradiates the reflected light or transmitted light of the ultraviolet light component from the light source to the illumination target position, and emits the ultraviolet light from the illumination target position. An ultraviolet light illumination device comprising: a beam splitter that irradiates image capturing means with component transmitted light or reflected light. 10. The ultraviolet light illuminating apparatus according to claim 9, wherein a quartz diffusion plate is used for the ultraviolet light diffusion means, and a semi-transparent mirror in which a partial reflection film is formed on the quartz plate is used for the beam splitter.

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