JP5629431B2 - Inspection lighting device - Google Patents

Description

  The present invention relates to an inspection illumination device used when imaging an inspection object having a convex shape toward a camera.

When inspecting whether or not a part whose surface is mirror-finished is a non-defective product, the part is photographed with a camera in a state where illumination is applied to the finished surface, and the quality is determined by image processing. For example, in the inspection apparatus disclosed in Patent Document 1, a hemispherical diffusion dome in which an imaging hole is formed at the top on the apex side, and a plurality of light sources installed at the bottom on the opening side of the diffusion dome The inspection object is photographed through the hole by a camera disposed above the illumination device.
JP 2002-22666 A

  However, in the illuminating device disclosed in Patent Document 1, the light source and the dome for diffusion are arranged above the inspection object on the camera side. Then, if the finished surface of the part is a spherical surface that is convex toward the camera, the light from the illumination cannot be directed to the camera by being applied to the vicinity of the equator, which is the maximum outer diameter part of the spherical surface. The whole part cannot be photographed with appropriate brightness.

  Therefore, an object of the present invention is to provide an illuminating device that can photograph an entire inspection object having a convex shape toward the camera with appropriate brightness.

The present invention has been made in view of the above circumstances, and the inspection illumination device according to the present invention is an illumination device used when photographing an inspection object having a convex hemisphere toward the camera, Surrounding from the light source to the rear of the maximum outer diameter portion of the inspection object around the imaging axis connecting the inspection object and the camera with the light source disposed in front of the camera closer to the inspection object A reflective housing that reflects light from the light source, and the reflective housing is disposed on a side of the object to be inspected so as to surround the imaging axis; and And a back reflection portion located behind the maximum outer diameter portion of the inspection object, and the light reflected by the back reflection portion is reflected by the hemispherical surface of the inspection object and enters the imaging section of the camera The back reflector is Protrudes from the serial side reflecting portion toward the inner diameter side, to the rear reflecting portion, characterized in that the out doorway said inspection object back and forth are formed.

According to the above configuration, since the reflection housing is provided so as to surround from the light source to the rear of the maximum outer diameter portion of the inspection object, even if the inspection object is convex toward the camera, The light reflected behind the object hits the vicinity of the maximum outer diameter portion of the inspection object and is guided to the camera. Therefore, the entire inspection object can be photographed with appropriate brightness as viewed from the camera. In addition, since the inspection object can be easily put in and out of the reflection housing through the doorway from the rear without passing through the front where the camera is located, photographing for inspection can be easily performed on a large number of inspection objects by a flow work. It can be done in a short time.

  The light emitted from the light source is directly reflected by the inspection object, and the light disposed between the light source and the inspection object in an optical path where the reflected light is directly incident on the camera. A diffusion plate may be further provided.

  According to the above configuration, light that is emitted from the light source and directly reflected by the inspection object without hitting the reflection housing is prevented from entering the camera with excessive brightness, and is excessively bright locally. It is possible to prevent an image from being taken.

  You may further provide the coaxial epi-illumination which radiate | emits the light which passed the diffuser plate from the said camera side coaxially with the said imaging axis | shaft.

  According to the said structure, the brightness of the center part of the test object seen from the camera can fully be ensured.

  The inspection object may have a hemispherical surface that is convex toward at least the camera, and the light source may be a ring light source disposed so as to surround the imaging axis.

  According to the said structure, the whole test object which has a hemispherical surface convex toward a camera can be image | photographed with appropriate brightness.

  As is apparent from the above description, according to the present invention, the entire inspection object can be photographed with appropriate brightness as viewed from the camera.

  Embodiments according to the present invention will be described below with reference to the drawings. In the following embodiments, “front” described in the claims is set to “upper” and “rear” is set to “lower”.

(First embodiment)
FIG. 1 is a configuration diagram showing an appearance inspection apparatus 1 having an illumination apparatus 6 according to the first embodiment of the present invention. As shown in FIG. 1, the appearance inspection apparatus 1 takes a picture with a camera in a state where illumination is applied to the finished surface of a workpiece 10 (inspection target) having a mirror-finished surface, and determines whether the work is good or bad by image processing. Is. The appearance inspection apparatus 1 includes a robot 2 that holds and conveys a workpiece 10, and a controller 3 is connected to the robot 2. A personal computer 4 for executing an inspection program is connected to the controller 3, and a camera is connected to the personal computer 4. The camera 5 is disposed above the workpiece 10 and points the imaging unit 5a downward so as to image the workpiece 10 positioned below it.

  The workpiece 10 is, for example, a piston used in a swash plate type piston pump. The workpiece 10 is continuous with a spherical portion 10a, a neck portion 10b having a smaller outer diameter than the spherical portion 10a, and a lower portion of the neck portion 10b. And a cylindrical portion 10c having an outer diameter larger than that of the neck portion 10b. That is, the workpiece 10 has a hemispherical surface convex toward the camera 5 in the spherical body portion 10a. A hole 10d is formed at the upper center of the sphere 10a. The surface of the sphere 10a is a rough surface only in the vicinity of the periphery of the hole 10d, and the remaining surface is a mirror-finished smooth surface.

  An illuminating device 6 is provided around the spherical portion 10a of the workpiece 10 that is gripped and positioned by the robot 2. The illuminating device 6 includes a ring light source 7 disposed above the work 5 and closer to the camera 5, and a reflection housing 8 that reflects light from the ring light source 7. The ring light source 7 is disposed so as to surround an imaging axis connecting the camera 5 and the workpiece 10 in an annular shape. The reflection housing 8 includes a light source installation portion 8a which is an annular plate fixed to the upper surface of the ring light source 7, a side reflection portion 8b which is a cylindrical plate continuous downward from the outer peripheral end of the light source installation portion 8a, And a rear reflecting portion 8c that is an annular plate protruding from the lower end portion of the side reflecting portion 8b toward the inner diameter side.

  The reflecting housing 8 reflects light at least on the inner surfaces of the side reflecting portion 8b and the rear reflecting portion 8c, and a diffusion layer for slightly diffusing the reflected light is formed on the inner surface. The light source installation part 8a and the side reflection part 8b are arranged so as to surround the imaging axis of the camera 5 in an annular shape. The rear reflecting portion 8c is located behind the maximum outer diameter portion 10e (equatorial portion) that is a portion that exhibits the maximum outer diameter D1 of the spherical portion 10a of the workpiece 10. The rear reflecting portion 8c is formed with an inlet / outlet 8d which is a circular hole through which the spherical portion 10a of the workpiece 10 can be taken in and out. The inner diameter D2 of the entrance / exit 8d is slightly larger than the maximum outer diameter D1 of the spherical portion 10a of the workpiece 10. Further, the inner peripheral end of the rear reflecting portion 8c is provided at a position where the light reflected by the rear reflecting portion 8c can be reflected at the maximum outer diameter portion 10e of the spherical body portion 10a or in the vicinity thereof and can enter the photographing portion 5a of the camera 5. It has been.

(Comparative example)
FIG. 3 is a main part configuration diagram showing an appearance inspection apparatus 100 having a lighting device of a comparative example. As shown in FIG. 3, in the appearance inspection apparatus 100 of the comparative example, an annular illumination device 101 is disposed above the spherical portion 10 a of the workpiece 10 and closer to the camera 5. The lighting device 101 is not provided with a reflector that surrounds the workpiece 10.

(Contrast of the present invention and comparative example)
FIG. 2 is an image obtained by photographing the workpiece 10 in the appearance inspection apparatus 1 shown in FIG. FIG. 4 is an image obtained by photographing the workpiece 10 in the comparative example of FIG. As shown in FIG. 4, in the image of the comparative example, the vicinity of the maximum outer diameter portion 10 e of the sphere portion 10 a of the workpiece 10 is photographed darkly. That is, in the comparative example, an image that was specularly reflected only in a part of the region was obtained, and the specular reflection could not be obtained over the entire upper half of the sphere 10a.

  On the other hand, as shown in FIG. 2, in the image of the present invention, the vicinity of the maximum outer diameter portion 10e of the spherical portion 10a of the workpiece 10 is also brightly photographed, and specular reflection is obtained over the entire upper half of the spherical portion 10a of the workpiece 10. I was able to. This is because the light emitted from the ring light source 7 is reflected by the rear reflecting portion 8c of the reflecting housing 8, and the light is reflected at or near the maximum outer diameter portion 10e of the spherical body portion 10a and enters the lens of the camera 5. Because. 2 and 4, the central portion of the sphere 10a is darkly displayed because the light incident on the hole 10d is not reflected toward the camera 5 and the vicinity of the hole 10d is rough. This is because the surface is not subject to inspection.

  According to the configuration of the present invention described above, even if the workpiece 10 has a convex shape toward the camera 5 as in the upper half of the sphere portion 10a, the reflective housing 8 is connected to the sphere portion of the workpiece 10 from the ring light source 7. Since it is provided so as to surround the rear of the maximum outer diameter portion 10e of 10a, the light reflected by the rear reflection portion 8c below (behind) the spherical portion 10a hits the vicinity of the maximum outer diameter portion 10e of the spherical portion 10a. Will be led to 5. Therefore, the entire spherical portion 10a of the work 10 as viewed from the camera 5 can be photographed with appropriate brightness.

  In addition, since the rear reflecting portion 8c of the reflecting housing 8 is provided with the entrance 8d, the spherical portion 10a of the workpiece 10 is moved rearward (lower) without inserting the workpiece 10 into the reflecting housing 8 from the front (upper). Can be easily taken into and out of the reflecting housing 8 through the entrance 8d. Therefore, when photographing a large number of workpieces 10 in a flow operation, the inspection operation can be performed easily and in a short time.

(Second Embodiment)
FIG. 5 is a block diagram showing an appearance inspection apparatus 21 having an illumination device 26 according to the second embodiment of the present invention. In addition, about the structure which is common in 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 5, in the appearance inspection apparatus 21 of the present embodiment, the light emitted from the ring light source 7 is directly reflected by the spherical portion 10 a of the workpiece 10, and the reflected light is directly reflected on the camera 5. A light diffusing plate 20 is disposed between the ring light source 7 and the workpiece 10 in an incident light path. Then, the light emitted from the ring light source 7 is diffused when passing through the light diffusion plate 20, and the diffused light is reflected by the work 10 and enters the camera 5.

  For example, when the workpiece 10 having a large spherical body 10a and a small inner diameter of the hole 10d is used, the direct light from the ring light source 7 is reflected around the hole 10d, and an extremely bright spot is generated on the image. There is a case. However, in this embodiment, since the light diffusing plate 20 is disposed in the optical path of the direct light, the light emitted from the ring light source 7 and directly reflected by the spherical portion 10a without hitting the reflecting housing 8 is excessive. Is prevented from entering the camera 5 with high brightness. Therefore, as shown in FIG. 6, it is possible to prevent an excessively bright image from being taken locally.

(Third embodiment)
FIG. 7 is a block diagram showing an appearance inspection apparatus 31 having illumination devices 26 and 36 according to the third embodiment of the present invention. In addition, about the structure which is common in 1st and 2nd embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted. As shown in FIG. 7, the workpiece 30 of the present embodiment includes a spherical portion 30a, a neck portion 30b having a smaller outer diameter than the spherical portion 30a, and a lower portion of the neck portion 30b. And a cylindrical portion 30c having a larger outer diameter than the neck portion 30b, and no concave portion is formed at the upper center of the spherical portion 30a.

  In the appearance inspection apparatus 31 according to the present embodiment, the camera 35 is provided with a coaxial incident illumination 36. In the coaxial epi-illumination 36, light from the light source 37 passes through the diffusion plate 38, and the light that has passed through is reflected by the half mirror 39 provided in the imaging unit 35 a of the camera 35, and is directed toward the workpiece 30 coaxially with the imaging axis. It is the structure which radiate | emits. Therefore, when there is no recess at the upper center of the spherical portion 30a of the workpiece 30, the central portion of the workpiece 30 viewed from the camera 35 can be photographed with sufficient brightness.

  In the above-described embodiments, the portions to be inspected are the spherical portions 10a and 30a. However, the shape is not limited to this as long as the shape is convex toward the camera 5. For example, the inspection object only needs to have at least a hemispherical shape, a polygonal shape, a pointed cross section, and more specifically, a hemispherical body, a cylindrical body, a cylindrical body, a polygonal columnar body, and the like. Good.

  As described above, the inspection illumination device according to the present invention has an excellent effect that the entire inspection object can be imaged with appropriate brightness when viewed from the camera, and performs a non-defective inspection based on the image captured by the camera. It is beneficial to apply to a wide range.

It is a block diagram which shows the external appearance inspection apparatus which has an illuminating device which concerns on 1st Embodiment of this invention. It is the image which image | photographed the test target object in the external appearance inspection apparatus shown in FIG. It is a principal part block diagram which shows the external appearance inspection apparatus which has an illuminating device of a comparative example. It is the image which image | photographed the test target object in the comparative example of FIG. It is a block diagram which shows the external appearance inspection apparatus which has an illuminating device which concerns on 2nd Embodiment of this invention. It is the image which image | photographed the test target object in the external appearance inspection apparatus shown in FIG. It is a block diagram which shows the external appearance inspection apparatus which has an illuminating device which concerns on 3rd Embodiment of this invention.

Explanation of symbols

5,35 Camera 6,26,32 Illumination device 7 Ring light source 8 Reflective housing 8d Entrance / exit 10, 30 Work 10a, 30a Spherical part (inspection object)
10e Maximum outer diameter 20 Light diffuser 36 Coaxial epi-illumination

Claims (4)

An illumination device used when imaging an inspection object having a hemispherical surface convex toward a camera,
A light source disposed in front of the inspection object closer to the camera;
A reflection housing that reflects light from the light source around an imaging axis connecting the inspection object and the camera, surrounding the light source from behind the maximum outer diameter portion of the inspection object; and
The reflection housing includes a cylindrical side reflection portion disposed on the side of the inspection object so as to surround the imaging axis, and a rear side positioned behind the maximum outer diameter portion of the inspection object. Having a reflection part,
The rear reflecting portion protrudes from the side reflecting portion toward the inner diameter side so that the light reflected by the rear reflecting portion is reflected by the hemispherical surface of the inspection object and is incident on the photographing portion of the camera. The illumination device for inspection, wherein the rear reflecting portion is formed with an entrance through which the inspection object can be taken in and out.   The light emitted from the light source is directly reflected by the inspection object, and the light disposed between the light source and the inspection object in an optical path where the reflected light is directly incident on the camera. The illumination device for inspection according to claim 1, further comprising a diffusion plate.   The inspection illumination device according to claim 1, further comprising coaxial epi-illumination that emits light that has passed through the diffusion plate from the camera side coaxially with the imaging axis. Before Symbol light source, inspection illumination device according to claim 1 to 3 characterized in that the ring light source is arranged to surround the image pickup axis.