JP2008128730A - Inspection device of inspection target - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inspection device of an inspection target capable of shortening the inspection time required in the inspection of the surface state of the surface to be inspected of the inspection target by expanding the inspection light emitted to the surface to be inspected of the inspection target. <P>SOLUTION: The inspection device of the inspection target is equipped with an inspection target holding part 15 for holding the inspection target 1 having the surface 10 to be inspected, a floodlight projection part 2 for projecting inspection light 8, a light guide member 3 which permits the transmission of the inspection light 8 projected from the floodlight projection part 2 and emits the inspection light 8 to the surface 10 to be inspected of the inspection target 1 and an imaging part 6 for imaging the reflected light 8h reflected from the surface 10 to be inspected of the inspection target 1. The light guide member 3 is formed on the side opposed to the surface 10 to be inspected of the inspection target 1 and equipped with an emitting surface 48, of which the cross section forms an arcuate protruded shape protruded to the surface 10 to be inspected, so as to irradiate the surface 10 to be inspected of the inspection target 1 with the inspection light 8 expanded in its emitting angle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an inspection object inspection apparatus for inspecting the surface state of an inspection object.

  Conventionally, an inner surface observation apparatus for observing an inner wall surface of a concave portion of an inspection object is known (Patent Document 1). This includes an optical transmission part that is inserted into the concave part of the inspection object, a light source for projecting the inspection light to the optical transmission part, and an optical transmission part that reflects the inner wall surface of the concave part of the inspection object. And an imaging unit that images the reflected light (Patent Document 1). According to this, it is possible to observe the inner wall surface of the concave portion of the inspection object.

Further, a surface inspection apparatus that can continuously inspect the shaft end surface and the inner wall surface of a cylindrical inspection object is known (Patent Document 2). The sensor head is inserted into the center hole of the cylindrical inspection object, the first reflection surface formed by the mirror surface provided at the tip of the sensor head, and the upper end side of the inspection object. A conical body having a second reflecting surface formed by a mirror surface of the arranged conical inner wall surface, a lifting drive unit for raising and lowering the sensor head, and reflected light reflected by the object to be inspected are received. And an imaging unit for imaging. According to this, the inspection light projected from the sensor head is reflected radially outward of the inspection object by the first reflecting surface at the tip of the sensor head, and further reflected by the second reflecting surface. Then, it proceeds along the axial length direction of the inspection object and moves toward the axial end surface of the inspection object.
JP 2001-281556 A JP-A-2005-291717

  According to the above-described apparatus, the inspection time for inspecting the surface condition (for example, the presence or absence of foreign matter) of the inspection surface of the inspection object requires a considerable time. For this reason, it is required to shorten the inspection time.

  The present invention has been made in view of the above circumstances, and is required for inspecting the surface state of the inspection surface of the inspection object by expanding the inspection light emitted toward the inspection surface of the inspection object. It is an object of the present invention to provide an inspection object inspection apparatus capable of shortening the inspection time.

  (1) An inspection object inspection apparatus according to aspect 1 is projected from an inspection object holding unit that holds an inspection object having a surface to be inspected, a light projecting unit that projects inspection light, and a light projecting unit. A light guide that transmits the inspection light and emits the inspection light toward the inspection surface of the inspection object, and an inspection device that includes an imaging unit that images the reflected light reflected by the inspection surface of the inspection object In the object inspection apparatus, the light guide is formed on the side of the inspection object that faces the inspection surface, so that the inspection light is irradiated on the inspection surface of the inspection object by expanding the emission angle of the inspection light. It is characterized in that it is provided with an exit surface having a circular arc shape projecting toward the surface to be inspected in a cross section.

  The light guide transmits inspection light. The light guide includes an emission surface formed on the side of the inspection object that faces the inspection surface. The exit surface has a circular arc shape protruding in a cross section toward the surface to be inspected, and the inspection light transmitted through the light guide is expanded toward the surface to be inspected of the inspection object to be expanded light. Therefore, even when the beam diameter of the inspection light before expansion is small, the inspection light is expanded to become expanded light, so that the irradiation area on the inspection surface of the inspection object increases. For this reason, the time for scanning the inspection surface of the inspection object is shortened. Accordingly, the inspection time required for inspecting the inspection surface of the inspection object is shortened.

  Here, it is preferable that the exit surface of the light guide is expanded into a fan shape (slit fan shape) that spreads the inspection light transmitted through the light guide toward the inspection surface of the inspection object. The inspection object is not particularly limited. The object to be inspected may have a cylindrical shape such as a cylindrical shape or a rectangular tube shape, or may have a bowl shape. The surface to be inspected of the inspection object may be an inner wall surface or an outer wall surface. The material of the object to be inspected is not particularly limited, and examples thereof include metals such as iron and aluminum alloys, resins, and ceramics. Examples of the inspection object include a cylinder of a brake device, a cylinder of an internal combustion engine and an external combustion engine.

  The above-described inspection object holding part may be any part as long as it holds the inspection object, and may simply place the inspection object, or may hold the inspection object with a mounting part such as a bolt. The light projecting unit can be a light source that projects inspection light such as laser light. A semiconductor laser is exemplified as the light source. The light guide transmits the inspection light projected from the light projecting unit and emits the inspection light toward the inspection surface of the inspection object. The light guide has an exit surface. The exit surface is formed on the side of the object to be inspected facing the surface to be inspected, has a circular arc shape protruding in the cross section toward the surface to be inspected, and inspects the inspection light transmitted through the light guide The beam diameter is expanded as it proceeds to the surface to be inspected of the object, and the light is expanded. The convex shape of the arc constituting the exit surface may be formed by a perfect circular arc or may be formed by an elliptical arc. It is preferable that the light guide includes a condensing optical component having a light condensing property for reducing the beam diameter of the inspection light before the inspection light is emitted from the emission surface. Examples of the condensing optical component include a GRIN lens, a tip ball lens, and a TEC fiber. The imaging unit captures reflected light reflected by the surface to be inspected of the inspection object, and preferably includes an imaging element such as a CCD.

  (2) According to the inspection object inspection apparatus according to aspect 2, in the above aspect, the light guide transmits inspection light along the light guide direction along the extending direction of the inspection surface of the inspection object. A light guide path and a reflection surface that reflects inspection light transmitted through the light guide path in a direction intersecting the light guide direction of the light guide path and toward the inspection surface of the inspection object . In this case, the inspection light transmitted through the light guide path is reflected by the reflection surface, and travels along the direction intersecting the light guide direction of the light guide path toward the inspection surface of the inspection object.

  (3) According to the inspection object inspection apparatus according to aspect 3, in the above aspect, the light guide path includes an optical fiber and a lens connected to the tip of the optical fiber, and the lens has a reflection surface and an emission surface. It is characterized by having a surface. In this case, the inspection light transmitted through the lens is reflected by the reflection surface of the lens and travels along the direction intersecting the light guide direction of the light guide and toward the inspection surface of the inspection object. Further, the reflected light reflected by the reflecting surface is emitted from the exit surface of the lens. Then, the inspection light emitted from the emission surface becomes expanded light that expands toward the inspection surface of the inspection object. For this reason, even when the beam diameter of the inspection light is small, the inspection light becomes spread light, so that the irradiation area on the inspection surface of the inspection object increases. For this reason, the time for scanning the inspection surface of the inspection object is shortened. Accordingly, the inspection time required for inspecting the inspection surface of the inspection object is shortened.

  As the above-described lens, a GRIN lens or a cylindrical lens is exemplified. A GRIN lens (gradient index lens), also called a gradient refractive lens, is a lens in which the refractive index continuously changes as a function of spatial coordinates in the lens medium, and has a light condensing property that narrows the beam diameter. Reduce diffusion. A cylindrical lens is a lens in which at least one surface is curved like a part of a cylinder. The optical fiber may be a step index type in which the core has a uniform refractive index, a graded index type having a refractive index distribution, or a TEC fiber.

  (4) According to the inspection object inspection apparatus according to aspect 4, in the above aspect, the light guide path is an optical fiber, a lens connected to the tip of the optical fiber, and a light transmission part provided at the tip of the lens. And the light transmission part includes a reflection surface and an emission surface. In this case, the inspection light transmitted through the light transmission portion is reflected by the reflection surface of the light transmission portion, and travels along the direction intersecting the light guide direction of the light guide path and toward the inspection surface of the inspection object. . Furthermore, the reflected light reflected by the reflection surface is emitted from the emission surface of the light transmission part. Then, the inspection light emitted from the emission surface becomes expanded light that expands toward the inspection surface of the inspection object. For this reason, even when the beam diameter of the inspection light is small, the inspection light becomes spread light, so that the irradiation area on the inspection surface of the inspection object increases. For this reason, the time for scanning the inspection surface of the inspection object is shortened. Accordingly, the inspection time required for inspecting the inspection surface of the inspection object is shortened. The spreading light is preferably a fan shape such as a slit fan shape.

  (5) According to the inspection object inspection apparatus according to aspect 5, in the above aspect, the inspection surface of the inspection object is a cylindrical inner wall surface or a cylindrical outer wall surface, and the light guide path is formed of the inspection object. A plurality of cylindrical inner wall surfaces or cylindrical outer wall surfaces are arranged in parallel at intervals around the center of the cylinder. The cylindrical shape includes a cylindrical shape and a rectangular tube shape. An example of the light guide path is an optical fiber. The optical fiber includes a TEC fiber. A TEC (thermally Expand Core) fiber is a fiber that changes the beam diameter of light by diffusing a dopant (GeO2, F, B, etc.) for controlling the refractive index distribution of the optical fiber into the optical fiber by heat. Since it has a light condensing property that reduces its diameter, it is advantageous for preventing diffusion of light.

  In this case, it is preferable that a holding element for holding a plurality of light guide paths is provided. The holding element preferably has a cylindrical shape such as a cylindrical shape having a central hole or a rectangular tube shape. As long as the light guide has a light guide function, the holding element does not necessarily have a light guide function. The central hole of the holding element preferably forms part of a reflected light path that reflects reflected light from the surface to be inspected and transmits reflected light toward the imaging unit. In this case, the central hole of the holding element forms a part of the reflected light path that reflects the reflected light toward the imaging surface of the object to be inspected and transmits the reflected light toward the imaging unit, thereby contributing to downsizing of the apparatus.

  (6) According to the inspection object inspection apparatus according to aspect 6, in the above aspect, the inspection object is inspected in the reflected light path that reflects the inspection surface of the inspection object and transmits the reflected light toward the imaging unit. A reflector is provided between the surface and the imaging unit, and the reflector includes a second reflecting surface that receives reflected light reflected by the surface to be inspected of the object to be inspected and reflects it toward the imaging unit. Yes. The second reflecting surface of the reflector receives the reflected light reflected by the surface to be inspected and reflects it toward the imaging unit. In this case, the reflected light reflected by the inspection surface of the inspection object can be favorably reflected by the reflector toward the imaging unit. Examples of the reflector include a cone mirror having a cone shape or a truncated cone shape.

  (7) According to the inspection object inspection apparatus according to aspect 7, in the above aspect, the sensor that holds at least the light guide and the imaging unit is provided, and the sensor is guided along the inspection surface of the inspection object. And a driving unit that moves the sensor along the surface to be inspected of the object to be inspected. In this case, since the sensor moves along the inspection surface of the inspection object, the inspection surface of the inspection object can be inspected by the light guide and the imaging unit mounted on the sensor. As a result, the inspection area of the inspection surface of the inspection object can be increased.

  According to the inspection object inspection apparatus according to the present invention, it is possible to inspect the surface condition (for example, the presence or absence of foreign matter) on the inspection surface of the inspection object. Furthermore, the inspection time required for the inspection of the inspection object can be shortened by expanding the inspection light emitted toward the inspection surface of the inspection object.

(Embodiment 1)
A first embodiment embodying the present invention will be described with reference to FIGS. FIG. 1 shows the concept of an inspection object inspection apparatus according to this embodiment. As shown in FIG. 1, the inspection object inspection apparatus includes an inspection object holding unit 15 having a mounting surface 15a for mounting and holding an inspection object 1 having an inner peripheral surface 10 to be inspected, and a laser beam. A projection unit 2 having a semiconductor laser that projects the inspection light 8 (wavelength: 660 nanometers), and the inspection surface of the inspection object 1 that transmits the inspection light 8 projected from the projection unit 2 10 includes a light guide 3 that emits inspection light 8 toward 10, and an imaging unit 6 that receives and captures reflected light reflected by the inspection surface 10 of the inspection object 1.

  The object to be inspected 1 is formed using a metal such as an iron alloy or an aluminum alloy as a base material, and has a cylindrical shape having a cylindrical hole-like cavity 14 whose center line M1 extends along the vertical direction (vertical direction). ing. The inspection object 1 has a cylindrical inner wall surface and a cylindrical outer wall surface 16 that become the inspection surface 10, and a shaft end surface 17. A surface 10 (inner wall surface) to be inspected 1 is covered with a plating film such as chrome plating. The outer wall surface 16 and the shaft end surface 17 of the inspection object 1 may be coated with a plating film. The inspection object 1 is exemplified by a cylinder of a brake device, a cylinder of an internal combustion engine or an external combustion engine.

  As shown in FIG. 1, the light guide 3 includes a plurality of light guides 4 and a cylindrical light guide holder 5 having a constant thickness that functions as a holding element that embeds and holds the plurality of light guides 4. And. The light guide path holding part 5 is formed of a light-transmitting resin (transparent resin such as acrylic resin) or a light-transmitting material such as glass, and has an inner diameter and an outer diameter that are equal along the axial direction. ing. The light guide holding unit 5 has an inner peripheral surface 5i and an outer peripheral surface 5p that define a central hole 5r that has a center line M2 and penetrates in the vertical direction (vertical direction). As shown in FIG. 1, the light guide 4 is along the vertical direction (vertical direction), and is embedded in the light guide holder 5. A plurality of the light guide paths 4 are arranged in parallel along the center line M2 of the cylindrical light guide path holding portion 5 (the center line M1 of the inspection object 1). The center line M2 of the light guide holding unit 5 is substantially coaxial with the center line M1 of the inspection object 1. The imaging unit 6 is arranged on the center line M1 or an extension line. The imaging unit 6 includes an optical lens system 60 that faces a reflector 9 described later, and a camera 61.

  The light guide 4 includes a plurality of optical fibers 40 that function as the light guide 4, and a lens 45 (microlens) having a light expanding function connected to the tip 40 f (lower end) of the optical fiber 40. In the optical fiber 40 constituting the light guide 4, the inspection light 8 passes through the inside of the optical fiber 40 along the length direction of the optical fiber 40. As shown in FIG. 1, the optical fiber 40 is covered along the extending direction (arrow H direction, vertical direction, axial length direction of the inspection object 1) of the inspection surface 10 that forms the cylindrical shape of the inspection object 1. It is arranged substantially parallel to the inspection surface 10. For this reason, the light guide direction in the optical fiber 40 is the extending direction of the inspection surface 10 of the inspection object 1. The plurality of optical fibers 40 (light guide paths 4) are substantially parallel to each other. The optical fiber 40 is circular in cross section and has an outer peripheral surface 40p, and may be made of glass or resin. The starting ends of the plurality of optical fibers 40 are connected to the light projecting unit 2. Accordingly, when the light projecting unit 2 projects the inspection light, the inspection light is branched into the plurality of optical fibers 40 and transmitted. Therefore, the light projecting unit 2 functions as a common light source for the plurality of optical fibers 40 (light guides 4).

  As shown in FIG. 3, the lens 45 disposed at the tip of the optical fiber 40 is a GRIN lens having a condensing property, and a joining surface 41 connected to the tip 40 f in the length direction of the optical fiber 40; It has a reflective surface 46 that is inclined obliquely, and an outer peripheral surface 47 that has an arcuate convex shape. The optical fiber 40 and the lens 45 are arranged coaxially so that the axis of the optical fiber 40 and the axis of the lens 45 are aligned. As shown in FIG. 3, the reflecting surface 46 is inclined at an angle θ1 with respect to a horizontal line (a virtual surface along the radial direction of the light guide path holding portion 5), and is an extension line of the center line M5 of the optical fiber 40. Is inclined at an angle θ2. By setting the angles θ1 and θ2, the direction of the inspection light 8 applied to the inspection surface 10 of the inspection object 1 can be adjusted. The reflection surface 46 may be formed of a base material of the lens 45, or may be formed by laminating thin films for promoting reflection of metal (aluminum or the like). A translucent portion 5k that forms part of the translucent light guide holding portion 5 is provided at the tip of the reflecting surface 46 (see FIG. 2). A part of the outer peripheral surface 47 of the lens 45 forms an emission surface 48 having a circular arc shape curved with a predetermined curvature. The exit surface 48 is a cross-section orthogonal to the extension line of the center line M5 of the optical fiber 40 (a cross-section orthogonal to the center line M1 of the surface 10 to be inspected 1), and is formed by a perfect circular arc. .

  As shown in FIG. 3, the inspection light 8 transmitted through the optical fiber 40 along the length direction reaches the lens 45 via the joint surface 41, and the inspection object 1 is inspected by the reflection surface 46 of the lens 45. The light is reflected toward the surface 10, and further emitted outward at the exit surface 48 of the lens 45. Accordingly, the inspection light 8 travels along the direction (arrow D1 direction) intersecting the light guide direction (arrow H direction) of the light guide 4 and toward the inspection surface 10 of the inspection object 1. Here, the exit surface 48 of the lens 45 is a cross section orthogonal to the extension line of the center line M5 of the optical fiber 40 (a cross section orthogonal to the center line M1 of the object 1). An arc convex shape is formed so as to protrude toward the surface 10 to be inspected. Therefore, as shown in FIGS. 3 and 4, the inspection light 8 emitted from the emission surface 48 is directed toward the inspection surface 10 of the inspection object 1 in the radial direction of the light guide path holding portion 5 having a cylindrical shape. It spreads outward (radiation direction) and becomes spread light.

  Specifically, the inspection light 8 emitted from the emission surface 48 travels obliquely downward along the outer diameter direction of the inspection object 1 (see FIG. 2), and the inspection object 1 from the emission surface 48. Expands into a horizontal fan shape toward the surface 10 to be inspected. As shown in FIGS. 1 and 3, the inspection light 8 expanded in a fan shape has an expanded outer edge 8a. Although the inspection light 8 projected from the light projecting unit 2 is a light beam having a small beam diameter as described above, the inspection light 8 emitted from the emission surface 48 is expanded in a horizontal fan shape (slit fan shape). Open. For this reason, in the circumferential direction of the inspection object 1, the irradiation area on the inspection surface 10 of the inspection object 1 increases.

  According to the present embodiment, the lens 45 (GRIN lens) has a function of improving the light condensing property of the inspection light 8 and also reflects the inspection light 8 toward the inspection object 1 by the reflection surface 46. And a spreading function for spreading the inspection light 8 in a fan shape by the emission surface 48. The focal point of the lens 45 is set to be the inspection surface 10 of the inspection object 1.

  When the inspection light 8 passes through the optical fiber 40, scattering of the inspection light 8 is suppressed. However, the inspection light 8 led out from the tip 40f of the optical fiber 40 tends to scatter, but the lens 45 (GRIN lens) connected to the tip 40f of the optical fiber 40 has a condensing function. , Scattering within the lens 45 is suppressed, and resolution is ensured.

  As shown in FIG. 2, when the inspection light 8 is reflected by the inner peripheral surface 10 of the inspection object 1, the inspection light 8 travels in the centripetal direction (D2 direction) of the inspection object 1. Here, as shown in FIG. 2, in the reflected light path that transmits the reflected light 8 h reflected by the surface 10 to be inspected 1, between the surface 10 to be inspected 1 and the imaging unit 6. Is provided with a reflector 9. The reflector 9 is disposed on the lower end portion of the inspection object 1 (the end side in the axial length direction of the inspection object 1). The reflector 9 is made of glass or resin. The reflector 9 is a cone mirror, and includes a top 90 with a sharp tip (upper end) and a second reflecting surface 92 having a conical shape. The reflector 9 is arranged coaxially with the cylindrical light guide path holding portion 5 so that the top 90 of the reflector 9 is positioned on the center line M2 of the light guide path holding portion 5. As a result, the reflected light 8h reflected by the second reflecting surface 92 travels in a ring shape toward the imaging unit 6 in the central hole 5r of the object to be inspected 1, so that the light receiving property in the imaging unit 6 is improved. The second reflecting surface 92 of the reflector 9 receives the reflected light 8h reflected by the surface 10 to be inspected 1 and reflects it toward the imaging unit 6 (upward). As a result, the reflected light 8h reflected in the centripetal direction (arrow D2 direction) on the surface 10 to be inspected 1 can be favorably reflected toward the imaging unit 6 by the second reflecting surface 92 of the reflector 9. it can. The reflected light 8h travels coaxially around the axis of the central hole 5r of the inspection object 1.

  As illustrated in FIG. 1, the light guide 3, the imaging unit 6, the reflector 9, the light projecting unit 2, and the like described above are held in the housing 100 h of the movable sensor 100. The sensor 100 has an arm 102. The drive unit 200 moves the sensor 100 along the extending direction (arrow H direction, height direction) of the inspection surface 10 of the inspection object 1. The drive unit 200 is equipped with a motor device or a fluid pressure cylinder device. The guide part 210 functioning as a sensor guide part is extended along the extension direction (arrow H direction) of the inspection object 1 in the housing 201 of the drive part 200. When the drive control unit 204 is controlled by the control signal of the control unit 300, the drive unit 200 is driven to move the sensor 100 along the extending direction (arrow H direction, vertical direction) of the inspection object 1 of the inspection object 1. To move. The inspection object holding unit 15, the sensor 100, and the driving unit 200 are held by the base 19 of the apparatus.

  A description will be given of how to use this apparatus. First, as shown in FIG. 1, the lower surface of the inspection object 1 is placed on the mounting surface 15 a of the inspection object holding portion 15 to hold the inspection object 1. The light projecting unit 2 projects the inspection light 8. Then, the inspection light 8 is branched into a plurality of light beams and is transmitted downward (arrow H2 direction) from the start end of each optical fiber 40 toward the tip end 40f. Accordingly, the light projecting unit 2 functions as a common light source for the plurality of optical fibers 40 (light guide paths 4). The inspection light 8 that has passed through the optical fiber 40 reaches the lens 45 through the joint surface 41, and the light guide path holding part 5 faces in the radially outward direction toward the surface to be inspected 10 of the inspection object 1 through the reflecting surface 46 of the lens 45. And is further emitted from the emission surface 48 of the lens 45 along the direction of the arrow D1 and toward the inspection surface 10 of the inspection object 1. Here, the exit surface 48 of the lens 45 has an arc convex shape curved with a predetermined curvature. Therefore, as shown in FIGS. 3 and 4, the inspection light 8 emitted from the emission surface 48 is directed toward the inspection surface 10 of the inspection object 1 in the radial direction of the light guide path holding portion 5 having a cylindrical shape. It spreads outward and becomes spread light. Specifically, the inspection light 8 emitted from the emission surface 48 expands in a horizontal fan shape (slit fan shape) from the emission surface 48 toward the inspection surface 10 of the inspection object 1. Thus, since the inspection light 8 expands into a substantially two-dimensional fan shape, the irradiation area on the inspection surface 10 of the inspection object 1 increases.

  As shown in FIG. 1, a plurality of light guide paths 4 are arranged side by side along the circumferential direction (arrow R direction) of the inspection object 1. For this reason, the expanded light expanded in a fan shape continues in a ring shape so as to make one round in the circumferential direction of the inspection object 1, and ring light 8 r is obtained. The peripheral edges of the fan-shaped spread light overlap each other. The ring light 8r means light from which inspection light is emitted in a ring shape. Since the ring light 8r is obtained as described above, the irradiation area on the surface to be inspected 10 of the inspection object 1 is ensured satisfactorily. Accordingly, the scanning for scanning the inspection light 8 in the circumferential direction of the inspection object 1 is reduced.

  When the inspection light 8 is reflected by the inspection surface 10 of the inspection object 1, the inspection light 8 travels in the centripetal direction (D2 direction) of the cavity 14 of the inspection object 1. Here, as shown in FIG. 2, the reflected light 8 h is reflected by the second reflecting surface 92 of the reflector 9, is transmitted upward through the central hole 5 r of the light guide path holding unit 5, travels toward the imaging unit 6, and is optically The light is received by the camera 61 through the lens system 60. The imaging signal of the camera 61 of the imaging unit 6 is stored in a predetermined area of the image memory 7 (image data storage element), and image processing using triangulation is performed by the control unit 300. As a result, the surface state (existence of foreign matter, etc.) of the inspection surface 10 of the inspection object 1 is inspected.

  The drive unit 200 is driven by the drive control unit 204 controlled by the control unit 300, and the sensor 100 moves along the axial length direction (arrow H direction) of the cavity 14 of the inspection object 1. It progresses gradually to the back (downward) of 14. As a result, the ring-shaped inspection light 8 (ring light 8r) moves downward along the axial length direction (arrow H direction) of the cavity 14 of the object 1 to be inspected, and gradually enters the depth of the cavity 14 of the object 1 to be inspected. Progress. As a result, the entire region or almost the entire surface 10 of the inspection object 1 is imaged. FIG. 1 is merely a conceptual diagram, and the actual axial length of the inspection object 1 is set to be longer than that shown in FIG. FIG. 5 shows an image captured by the imaging unit 6 at a predetermined timing. If there is a convex foreign object on the surface 10 to be inspected 1, the convex foreign object is inspected in the image as shown in FIG. 5.

  FIG. 6 shows an example of a flowchart executed by the control system. The flowchart is not limited to this. First, a command to set the inspection object 1 in the inspection object holding unit 15 is output to a transport device (not shown) (step S102). The sensor 100 is moved to the measurement start position of the inspection object 1 (step S104). The inspection light 8 is projected from the light projecting unit 2, and the ring light 8r is irradiated onto the surface 10 to be inspected 1 (step S106). Image data is captured (step S108). The image data is stored in a predetermined area of the image memory 7 (step S110). The shape of the inspection surface 10 of the inspection object 1 is calculated (step S112). Next, it is determined whether the measurement is completed (step S114). If the measurement is not finished (NO in step S114), the sensor 100 is further moved along the inspection surface 10 of the inspection object 1 in the arrow H direction (step S116). If the measurement is completed, the inspection surface shape of the inspection surface 10 of the inspection object 1 is constructed (step S118). The shape of the foreign matter on the surface 10 to be inspected 1 is extracted (step S120). An OK / NG determination is made (step S122). If OK, an OK signal is output (step S124), and if NG, an NG signal is output (step S126).

  As described above, according to the present embodiment, the inspection light 8 expands in a fan shape, so that the irradiation area on the inspection surface 10 of the inspection object 1 increases. Therefore, scanning for scanning the inspection light 8 in the circumferential direction of the inspection object 1 is reduced, and the inspection time for inspecting the inspection surface 10 of the inspection object 1 can be shortened. In particular, since the ring light 8r that makes one round around the surface 10 to be inspected 1 is formed, the scanning for scanning the inspection light 8 in the circumferential direction of the object 1 is reduced. The inspection time for inspecting the surface to be inspected 10 can be shortened. Furthermore, when foreign matter is present on the surface 10 to be inspected 1, the amount of unevenness of the foreign matter and the amount of unevenness of the plating unevenness are considerably different, so that the foreign matter and the plating unevenness can be distinguished. Therefore, it can be applied to the inspection of the presence or absence of foreign matter on the surface 10 to be inspected.

(Embodiment 2)
7 to 9 show the second embodiment. This embodiment has basically the same configuration as that of the first embodiment, and has the same functions and effects. The parts having the same functions as those in the first embodiment are denoted by the same reference numerals. Hereinafter, a description will be given centering on parts different from the first embodiment. As shown in FIG. 7, a cylindrical light guide 3 includes a plurality of light guides 4 and a cylindrical light guide holder having a constant thickness that functions as a holding element that holds the plurality of light guides 4. And 5. The light guide path holding part 5 is formed of a light-transmitting resin (transparent resin such as acrylic resin) or a light-transmitting material such as glass, and has an inner diameter and an outer diameter that are equal along the axial direction. ing. The light guide path holding part 5 has a right cylindrical shape having an inner peripheral surface 5i and an outer peripheral surface 5p that define the central hole 5r. As shown in FIG. 7, the light guide 4 is along the vertical direction (vertical direction, the extension direction of the surface 10 to be inspected 1) and is embedded and held inside the light guide holder 5. ing. A plurality of light guide paths 4 are arranged in parallel along the center line M2 of the light guide path holding portion 5 having a cylindrical shape (that is, the center line M1 of the inspection object 1).

  As shown in FIGS. 8 and 9, the light guide 4 is connected to a TEC fiber 42 (condensing optical component) that functions as a plurality of optical fibers that perform a light guiding function, and a tip 42 f (lower end) of the TEC fiber 42. And a cylindrical lens 45S functioning as a lens having a light spreading function. In the TEC fiber 42 constituting the light guide path 4, the inspection light 8 is transmitted along the length direction of the TEC fiber 42. The TEC fiber 42 is disposed substantially in parallel with the surface 10 to be inspected along the extending direction (arrow H direction, vertical direction) of the surface 10 to be inspected 1. For this reason, the light guide direction in the TEC fiber 42 is the extending direction of the inspection surface 10 of the inspection object 1. The TEC fiber 42 is circular in cross section and has an outer peripheral surface 42p.

  The cylindrical lens 45S has a joint surface 41 connected to the longitudinal end 42f of the TEC fiber 42, a reflective surface 46 that is inclined obliquely, and an outer peripheral surface 45Sp that has an arcuate convex shape. The TEC fiber 42 and the cylindrical lens 45S are coaxially connected so that the axis of the TEC fiber 42 and the axis of the cylindrical lens 45S are aligned.

  A part of the outer peripheral surface 45Sp with the cylindrical lens 45S forms an emission surface 48 that is bent with a predetermined curvature. The exit surface 48 is a cross section orthogonal to the extension line of the center line M6 of the TEC fiber 42 (or a cross section orthogonal to the center line M1 of the inspection object 1), and is on the inspection surface 10 of the inspection object 1. It has a circular arc shape that protrudes toward it. As shown in FIG. 9, the reflecting surface 46 is inclined at an angle θ1 with respect to a horizontal line (virtual surface along the radial direction of the light guide path holding portion 5), and is an extension of the center line M6 of the TEC fiber 42. It is inclined at an angle θ4 with respect to the line. A translucent portion 5k that forms part of the translucent light guide holding portion 5 is provided at the tip of the reflecting surface 46 (see FIG. 8). In this case, as shown in FIG. 9, the inspection light 8 transmitted through the TEC fiber 42 along the length direction reaches the cylindrical lens 45S via the joint surface 41, and is inspected by the reflection surface 46 of the cylindrical lens 45S. The object 1 is reflected toward the surface 10 to be inspected, and is further emitted outward from the emission surface 48 of the cylindrical lens 45S. Accordingly, the inspection light 8 travels along the direction (arrow D1 direction) intersecting the light guide direction (arrow H direction) of the light guide 4 and toward the inspection surface 10 of the inspection object 1. Here, as described above, the emission surface 48 of the cylindrical lens 45S has an arcuate convex shape. Therefore, as shown in FIGS. 7 and 9, the inspection light 8 emitted from the emission surface 48 has a horizontal fan shape (slit fan shape, as it goes from the emission surface 48 toward the inspection surface 10 of the inspection object 1. Expands to an expansion angle θ3). The inspection light 8 expanded in a fan shape has an expanded outer edge 8a. Although the inspection light 8 projected from the light projecting unit 2 is a beam light as described above, the inspection light 8 emitted from the emission surface 48 is expanded in a horizontal fan shape (slit fan shape). In the circumferential direction of the inspection object 1, the irradiation area on the inspection surface 10 of the inspection object 1 increases.

  According to the present embodiment, the TEC fiber 42 functions to improve the light collecting property of the inspection light 8. The cylindrical lens 45S has a reflection function for reflecting the inspection light 8 toward the inspection object 1 by the reflection surface 46 and a spreading function for expanding the inspection light 8 by the emission surface 48. As shown in FIGS. 8 and 9, since the tip 42f of the TEC fiber 42 that enhances the light collecting property is disposed near the reflecting surface 46 of the cylindrical lens 45S, the scattering of the inspection light 8 is suppressed, and the resolution is improved. Is secured.

  Also in the present embodiment, as shown in FIG. 8, when the inspection light 8 is reflected by the inspection surface 10 of the inspection object 1, it goes in the centripetal direction (D2 direction) of the inspection object 1. Here, the reflected light 8h reflected in the centripetal direction (D2 direction) on the surface 10 to be inspected 1 is favorably directed toward the imaging unit 6 (upward) by the second reflecting surface 92 of the reflector 9. Reflect.

  As described above, according to the present embodiment, the inspection light 8 is expanded into a fan shape (slit fan shape) by the emission surface 48 of the cylindrical lens 45S, as in the case of the first embodiment, and thus the inspection object 1 Ring light 8r that goes around the surface 10 to be inspected once is obtained, and the irradiation area of the surface 1 to be inspected 1 increases. Therefore, when inspecting the surface 10 to be inspected, the scan for scanning the inspection light 8 in the circumferential direction of the inspection object 1 is reduced. Therefore, the inspection time required for the inspection of the inspection surface 10 of the inspection object 1 can be shortened. Further, when foreign matter is present on the surface 10 to be inspected 1, it is possible to discriminate between foreign matter and plating unevenness, which can be applied to the inspection for the presence of foreign matter.

(Embodiment 3)
10 to 12 show the third embodiment. This embodiment has basically the same configuration as that of the first embodiment, and has the same functions and effects. The parts having the same functions as those in the first embodiment are denoted by the same reference numerals. Hereinafter, a description will be given centering on parts different from the first embodiment. As shown in FIGS. 10 and 11, the light guide path 4 includes an optical fiber 40, a tip spherical lens 43 t having a convex lens surface 43 u connected to the tip of the optical fiber 40, and a tip of the tip spherical lens 43. The light transmission part 44 provided is provided. The optical fiber 40 and the tip ball lens 43 form a tip processing optical fiber.

  As shown in FIGS. 10 and 11, the light transmitting portion 44 has a cylindrical shape formed of a light transmitting material such as transparent resin (for example, acrylic resin) or transparent glass, and is coaxial with each other. Are formed by a vertical inner cylinder 441 and a vertical outer cylinder 442, and are provided with a central hole 445 penetrating in the vertical direction. Since the inner cylinder 441 holds the optical fiber 40 and the tip ball lens 43t, the light transmission part 44 also functions as a light guide path holding part. The inner cylinder 441 does not necessarily have light transmittance, but may have it. The lens surface 43u of the front lens 43t has a light collecting function for reducing the beam diameter. As a result, it can be reduced to about 1/10 (about 0.01) compared to the NA (numerical aperture) of the normal optical fiber 40, and the resolution can be increased. Since the cylindrical light transmission portion 44 formed of a light transmission material is used as a light guide path, the length of the optical fiber 40 can be shortened, and the assembly property of the plurality of optical fibers 40 can be improved.

  As shown in FIG. 11, a reflection surface 46 is formed at the lower end portion of the outer cylinder 442 constituting the light transmission portion 44. The reflection surface 46 is inclined in a conical shape around the center line M4 of the cylindrical light transmission portion 44. A thin reflective film such as metal may or may not be formed on the reflective surface 46. The inner diameter of the reflecting surface 46 is set so as to become smaller toward the imaging unit 6.

  A lower end portion of the outer peripheral surface of the outer cylinder 442 constituting the light transmission portion 44 is an emission surface 48. The emission surface 48 is an arc convex surface curved with a predetermined curvature and protrudes toward the inspection surface 10 of the inspection object 1 in a cross section orthogonal to the center line of the light transmitting portion 44. ing.

  When the light projecting unit 2 projects the inspection light 8, the inspection light 8 is branched into a plurality of light beams that are transmitted in the direction of the arrow H <b> 2 from the start end of each optical fiber 40 toward the front end 40 f. The inspection light 8 transmitted through the optical fiber 40 reaches the tip spherical lens 43t through the joint surface 41, passes through the inside of the outer tube 442 of the light transmission portion 44 from the tip spherical lens 43t, and is a reflection surface of the light transmission portion 44. To 46. The inspection light 8 is reflected by the reflection surface 46 of the outer cylinder 442 of the light transmission portion 44 toward the inspection surface 10 of the inspection object 1 in the radially outward direction of the light guide path holding portion 5, and the inspection light 8 is further transmitted. The light is emitted from the emission surface 48 of the outer cylinder 442 of the light transmitting portion 44 along the direction of the arrow D1 and toward the inspection surface 10 of the inspection object 1.

  Here, as described above, the exit surface 48 of the light transmitting portion 44 has a cross-sectionally arc-shaped convex shape with a predetermined curvature. For this reason, as shown in FIG. 10, the inspection light 8 emitted from the emission surface 48 is directed outwardly in the radial direction of the light guide path holding portion 5 having a cylindrical shape toward the inspection surface 10 of the inspection object 1. It spreads toward and becomes spread light. Specifically, the inspection light 8 emitted from the emission surface 48 expands in a horizontal fan shape (slit fan shape) from the emission surface 48 toward the inspection surface 10 of the inspection object 1. Thus, since the inspection light 8 expands in a horizontal fan shape, the irradiation area on the inspection surface 10 of the inspection object 1 increases.

  As shown in FIG. 10, a plurality of optical fibers 40 constituting the light guide path 4 are arranged in parallel along the inner wall surface of the cavity 14 of the inspection object 1 along the circumferential direction (arrow R direction) of the inspection object 1. Has been. For this reason, the expanding light expanded in a fan shape is caused to make one round along the circumferential direction of the inspection object 1 on the inner wall surface of the cavity 14 of the inspection object 1. Continuous in a ring shape. The edges of each spreading light overlap each other. In this way, the ring light 8r that makes one round in the circumferential direction of the inspection object 1 is obtained. Since such ring light 8r is obtained, the irradiation area on the surface to be inspected 10 of the inspection object 1 is ensured satisfactorily. Accordingly, the scanning for scanning the inspection light 8 in the circumferential direction of the inspection object 1 is reduced.

  When the inspection light 8 is transmitted through the optical fiber 40, scattering of the inspection light 8 is suppressed. When the inspection light 8 exits the tip 40f of the optical fiber 40, the scattering property of the inspection light 8 becomes high. In this regard, according to the present embodiment, since the tip spherical lens 43t that functions as a condensing lens for reducing the beam diameter is provided between the optical fiber 40 and the light transmitting portion 44, the lens surface of the tip spherical lens 43t. The light condensing property of the inspection light 8 derived from 43u is enhanced. Therefore, the scattering of the inspection light 8 in the light transmitting portion 44 is suppressed, and the resolution is ensured. The focal point of the lens surface 43u of the front lens 43t is set to be the surface to be inspected 10 of the object 1 to be inspected.

  When the inspection light 8 is reflected by the inspection surface 10 of the inspection object 1, as shown in FIG. 11, the inspection light 8 moves in the centripetal direction (D2 direction) of the cavity 14 of the inspection object 1. Here, as shown in FIG. 11, the reflected light 8 h is reflected by the second reflecting surface 92 of the reflector 9, passes upward through the central hole of the light guide path holding unit 5, and moves toward the imaging unit 6 (upward). Opposite), the light is received by the camera 61 through the optical lens system 60. An imaging signal of the camera 61 of the imaging unit 6 is stored in the image memory 7 and is subjected to image processing by the control unit 300. The drive unit 200 controlled by the control unit 300 causes the sensor 100 to move along the axial length direction (arrow H direction) of the cavity 14 of the inspection object 1 and to the back (downward) of the cavity 14 of the inspection object 1. Progresses gradually. As a result, the ring-shaped inspection light 8 (ring light 8r) moves along the axial length direction (arrow H direction) of the cavity 14 of the inspection object 1 and gradually advances to the back of the cavity 14 of the inspection object 1. To go. As a result, the entire area or almost the entire area 10 of the inspection object 10 is imaged and inspected. If a convex foreign matter exists on the surface 10 to be inspected 1, the convex foreign matter is inspected in the image as shown in FIG. 6.

(Embodiment 4)
FIG. 13 shows a fourth embodiment. The present embodiment has basically the same configuration as that of the third embodiment, and has the same functions and effects. Parts having the same functions as those in the third embodiment are denoted by the same reference numerals. Hereinafter, a description will be given centering on parts different from the first embodiment. Furthermore, instead of the combination of the optical fiber 40 and the tip ball lens 43t, a combination of the optical fiber 40 and the GRIN lens 45 may be used as shown in FIG. A GRIN lens 45 is connected to the tip of the optical fiber 40. The inspection light 8 derived from the tip of the optical fiber 40 attempts to scatter (light portion 8x), but the GRIN lens 45 has a light condensing property that narrows the beam diameter, so that the scattering is suppressed. The GRIN lens 45 is connected to the upper part of the light transmission part 44.

(Embodiment 5)
FIG. 14 shows a fifth embodiment. The present embodiment has basically the same configuration as that of the third embodiment, and has the same functions and effects. Parts having the same functions as those in the third embodiment are denoted by the same reference numerals. Hereinafter, a description will be given centering on parts different from the first embodiment. Furthermore, in place of the combination of the optical fiber 40 and the tip lens 43t, a TEC fiber 42 may be used as shown in FIG. Since the TEC fiber 42 has a light condensing property, light scattering is suppressed. The tip 42 f of the TEC fiber 42 is connected to the upper part of the light transmission part 44.

(Other)
The present invention is not limited to the embodiments described above and shown in the drawings, and can be implemented with appropriate modifications within the scope not departing from the gist. The inspection object 1 is not limited to a cylindrical shape, and may be a rectangular tube shape. The inspected object 1 may have a cylindrical shape that makes one round around the center line M1, but may have a cylindrical shape that makes about 3/4 rounds around the center line M1, and almost half a round around the center line M1. It may be a bowl shape. The detection light 8 is a ring light 8r that goes around the surface 10 to be inspected 1 of the object 1 to be inspected, but it may be a partial ring light that goes around 3/4 of the surface 10 to be inspected 1 Or it is good also as a half ring light which makes the to-be-inspected surface 10 of the to-be-inspected object 1 a halve.

  The inspected object 1 is not limited to the longitudinal cylindrical shape in which the center line M1 extends along the vertical direction, and the center line M1 may have a cylindrical shape extending in the horizontal direction. In this case, the light guide 3 is moved in the lateral direction. Alternatively, as the inspection object 1, the center line M1 may be inclined. In this case, the light guide 3 is moved in an oblique direction. The material of the object to be inspected 1 is not limited to metal, but may be ceramic, carbon, hard resin, or the like.

  In the embodiment described above, the inspection surface 10 of the inspection object 1 is an inner wall surface, but the outer wall surface 16 of the inspection object 1 may be the inspection surface. In this case, the inner diameter of the light guide 3 is set to be larger than the outer diameter of the outer wall surface 16 of the inspection object 1 so that the outer wall surface 16 of the inspection object can be covered with the light guide body 3.

  INDUSTRIAL APPLICABILITY The present invention can be used for an inspection apparatus that inspects the surface state (for example, the presence or absence of foreign matter) of an inspection object surface.

1 is a conceptual diagram of an inspection object inspection apparatus according to Embodiment 1. FIG. FIG. 3 is a conceptual diagram illustrating a cross section of the inspection object inspection apparatus according to the first embodiment. It is a perspective view which shows the state which concerns on Embodiment 1 and the test | inspection light which permeate | transmitted the optical fiber is expanded in the fan shape by the output surface of the GRIN lens. 1A is a conceptual diagram illustrating a state in which inspection light transmitted through an optical fiber is expanded in a fan shape by a GRIN lens according to the first embodiment, and FIG. 2B is a fan shape for inspection light by a GRIN lens. It is a figure which shows the state which is irradiating the to-be-inspected surface of the to-be-inspected object with the ring light expanded in FIG. It is a figure which concerns on Embodiment 1 and shows the imaging form which test | inspected the foreign material with ring light. 6 is a flowchart executed by the control unit according to the first embodiment. FIG. 6 is a conceptual diagram of an inspection object inspection apparatus according to a second embodiment. It is a conceptual diagram which concerns on Embodiment 2 and shows the cross section of a to-be-inspected object inspection apparatus. It is a perspective view which shows the state which concerns on Embodiment 2 and has expanded the test | inspection light which permeate | transmitted the TEC fiber in the fan shape with the output surface of the TEC fiber. FIG. 10 is a conceptual diagram of an inspection object inspection apparatus according to a third embodiment. It is a conceptual diagram which concerns on Embodiment 3 and shows the cross section of a to-be-inspected object inspection apparatus. It is a perspective view which shows the state which concerns on Embodiment 3 and is condensing with the tip ball lens connected to the front-end | tip of an optical fiber. It is a perspective view which shows the state which concerns on Embodiment 4 and is condensed with the GRIN lens connected to the front-end | tip of an optical fiber. FIG. 10 is a perspective view illustrating a state in which inspection light is transmitted through a TEC fiber according to the fifth embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 is to-be-inspected object, 10 is to-be-inspected surface, 15 is to-be-inspected object holding | maintenance part, 19 is a base, 2 is a light projection part, 3 is a light guide, 4 is a light guide path, 5 is a light guide path holding part (holding element ) 5r is a central hole, 40 is an optical fiber, 41 is a cemented surface, 45 is a lens, 46 is a reflective surface, 48 is an exit surface, 42 is a TEC fiber, 43 is a front lens, 6 is an imaging unit, and 61 is a camera. , 7 is an image memory, 8 is inspection light, 8r is ring light, 9 is a reflector, 92 is a second reflecting surface, 100 is a sensor, 200 is a drive unit, 210 is a guide unit, and 300 is a control unit.

Claims (10)

An inspection object holding unit for holding an inspection object having an inspection surface;
A light projecting unit for projecting inspection light;
A light guide that transmits the inspection light projected from the light projecting unit and emits the inspection light toward the inspection surface of the inspection object; and
In the inspection object inspection apparatus comprising an imaging unit that images reflected light reflected by the inspection surface of the inspection object,
The light guide is
Formed on the side of the object to be inspected that faces the surface to be inspected, and inspects the surface of the object to be inspected so as to irradiate the surface of the object to be inspected by expanding the exit angle of the inspection light. An inspection object inspection apparatus comprising an emission surface having a circular arc shape protruding toward a surface.   2. The object according to claim 1, wherein the emission surface of the light guide body expands inspection light transmitted through the light guide body into a fan shape that spreads toward the inspection surface of the inspection object. Inspection object inspection device.   3. The light guide according to claim 1, wherein the light guide transmits the inspection light along a light guide direction along an extending direction of the inspection surface of the inspection object, and transmits the light guide. A test object inspection comprising: a reflection surface that reflects the test light in a direction intersecting the light guide direction of the light guide and toward the test surface of the test object. apparatus.   4. The inspection object according to claim 3, wherein the inspection surface of the inspection object is a cylindrical inner wall surface or a cylindrical outer wall surface, and the light guide path is the cylindrical inner wall surface or the cylindrical outer wall surface of the inspection object. A plurality of inspected devices are arranged in parallel around the center of the tube at intervals.   5. The light guide path according to claim 4, wherein the light guide path includes an optical fiber and a lens connected to a tip portion of the optical fiber, and the lens includes the reflection surface and the emission surface. Inspection object inspection device.   5. The light guide path according to claim 4, wherein the light guide path includes an optical fiber, a lens connected to a distal end portion of the optical fiber, and a light transmission portion provided at the tip of the lens. An inspection object inspection apparatus comprising a reflection surface and the emission surface.   The inspection object inspection apparatus according to claim 4, wherein a holding element that holds a plurality of the light guide paths is provided.   8. The reflected light path according to claim 7, wherein the holding element has a cylindrical shape having a central hole, and the central hole reflects reflected light from the surface to be inspected of the inspection object and transmits reflected light toward the imaging unit. An inspection object inspection apparatus characterized by forming a part of the inspection object.   9. The reflected surface of the inspection object according to claim 1, wherein the reflected light path reflects reflected light from the inspection surface of the inspection object and transmits reflected light toward the imaging unit. A reflector is provided between the imaging unit, and the reflector receives the reflected light reflected by the surface to be inspected of the object to be inspected and reflects the reflected light toward the imaging unit. An inspection object inspection apparatus characterized by comprising:   The guide unit according to claim 1, wherein a sensor that holds at least the light guide and the imaging unit is provided, and guides the sensor along the inspection surface of the inspection object. And a drive unit for moving the sensor along the surface to be inspected of the object to be inspected.

Images