JP2005337853A - Illuminator for visual examination - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive illuminator with a simple constitution suitable for measuring an article to be inspected having columnar or cross-sectionally arcuate mirror surface reflecting characteristics continuously moved in an axial direction. <P>SOLUTION: In the illuminator 10 used for the visual examination of the article 20 to be inspected having columnar or cross-sectionally arcuate mirror surface reflecting characteristics continuously moved in the axial direction, the illuminator has an arcuate shape and is arranged so that its center axis coincides with the center axis of the article to be inspected and has a diffusing light emitting source on its arcuate inner peripheral surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an illuminating device used for appearance inspection of an article at a site such as a manufacturing site or physical distribution, and more specifically, used for an appearance inspection of an inspected article having specular reflection characteristics such as metallic luster. The present invention relates to a lighting device.

  Conventionally, when performing an appearance inspection of an inspection object having a specular reflection characteristic such as metallic luster in an inspection process at a manufacturing site, the illumination light that is regularly reflected on the surface of the inspection object is imaged with a camera or the like. It has been broken. In this case, in order to clearly extract minute scratches and defect shapes on the surface of the inspection object, it is necessary to obtain specular reflection light from the entire outer peripheral surface of the inspection object surface. A method in which surface illumination devices are arranged in the form of a screen in the vicinity of the inspection object, and the entire surface of the inspection object is irradiated with uniform diffused light, or a method of irradiating the surface of the inspection object with uniform diffusion light using a diffusion dome, etc. Has been proposed (see, for example, Patent Document 1).

JP 2001-108639 A

  However, the conventional illumination method is suitable when the object to be inspected is a plate-like individual one by one, but it has a cylindrical or cross-sectional arcuate specular reflection characteristic that moves continuously in the axial direction. In the case of measuring an inspected article, there is a problem in that the shape of the illuminating apparatus becomes complicated because of interference between the extension line of the inspected article and the illuminating apparatus. Further, when the surface illumination device is used, even if the light emission of the surface illumination device is uniform, the part of the article to be inspected at a position near the surface illumination apparatus and the part of the article to be inspected at a position far from the surface illumination apparatus And the like, the amount of specular reflection light becomes non-uniform. Furthermore, in the case of using a diffusion dome, in addition to the above-described problems, there has been a problem that the price is expensive.

  Accordingly, an object of the present invention is to provide an inexpensive illumination device with a simple configuration suitable for measuring an article to be inspected having a specular reflection characteristic of a cylindrical shape or a circular arc shape that continuously moves in the axial direction. It is in.

  In order to achieve the above object, an illuminating device according to claim 1 is an illuminating device used for visual inspection of an article to be inspected having a specular reflection characteristic of a cylindrical shape or a circular arc shape that continuously moves in the axial direction. The lighting device has an arch shape, the central axis of the lighting device is aligned with the central axis of the article to be inspected, and each point of the inspection target area of the outer peripheral surface of the article to be inspected is arranged on the inner peripheral surface of the arch. After regular reflection, the light source has a diffused light source that has a light emitting surface shape that emits a light beam that passes through the center of the lens of the camera.

  In the lighting device according to claim 2, in addition to the configuration of the lighting device according to claim 1, the diffuse light emission source of the inner peripheral surface of the arch is arranged on the inner peripheral surface of the arch toward the axial direction of the arch. A light emitter and a light diffusing plate installed between the light emitter and the article to be inspected are configured.

  In addition to the configuration of the illuminating device according to claim 1, the illuminating device according to claim 3 is a light emission in which a diffused light emission source on the inner peripheral surface of the arch is disposed at the inner lower portion of the arch toward the inner peripheral surface of the arch. A body and a diffuse reflector formed on the inner peripheral surface of the arch.

  Here, the “diffuse reflector” in the present invention means a reflector whose incident angle and reflection angle are not equal. For example, the surface of the aluminum material is intentionally textured or uneven. Is obtained. In addition, the type of the “light emitter” in the present invention is not particularly limited, but a light emitting diode is preferably used from the viewpoint of power consumption, durability, and the like.

  According to the illuminating device according to claim 1, the arch shape is formed, the central axis of the arching device is arranged so that the central axis of the article to be inspected coincides, and the outer peripheral surface of the inspected article is inspected on the inner peripheral surface of the arch. A cylindrical shape that moves continuously in the axial direction because it has a diffused light source that has a light emitting surface shape that emits light rays that pass through the center of the camera lens after regular reflection at each point in the area. Alternatively, the inspection efficiency of the appearance inspection of the inspected article having the specular reflection characteristic having the arcuate cross section is remarkably improved. Moreover, since the shape of the lighting device is simple, the cost of the device can be reduced. Furthermore, since there is no interference between the moving direction of the article to be inspected and the illumination device, the design of the inspection device can be facilitated.

  According to the illuminating device according to claim 2, in addition to the effect produced by the illuminating device according to claim 1, the diffused light source is disposed on the inner peripheral surface of the arch toward the axial direction of the arch; and By comprising the light diffusing plate installed between the light emitter and the article to be inspected, unnecessary light emitting portions as illumination light can be eliminated, and power saving can be achieved.

According to the illuminating device according to claim 3, in addition to the effect produced by the illuminating device according to claim 1, the illuminant in which the diffused light source is disposed on the inner lower surface of the arch toward the inner peripheral surface of the arch, and the arch The structure of the diffuse reflector formed on the inner peripheral surface can simplify the structure of the arch portion.
In addition, according to the illumination device of the present invention, since the light emitting surface has a shape that is not excessive or insufficient for imaging a specularly reflected light image from a normal shape inspection target region, abnormal shapes such as surface irregularities can be formed. It can be detected with high sensitivity as brightness on the screen.

  Hereinafter, the lighting device according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows an apparatus configuration when performing an appearance inspection of an inspected article 20 having a cylindrical specular reflection characteristic that moves continuously in the axial direction by using the illumination apparatus 10 of the present invention.

  The lighting device 10 has an arch shape, and the inner peripheral surface of the arch diffuses and emits light when energized. Various methods can be considered for diffusing light emission on the inner peripheral surface of the arch. As an example, as shown in FIG. 2, a plurality of light emissions are directed toward the axial direction of the arch on the inner peripheral surface of the arch 16. It is obtained by disposing the diode 12 and installing a light diffusion plate 14 made of an acrylic plate or the like in front of the light emitting diode. By adopting such a configuration, only the inner peripheral surface of the arch can be made to emit light, and a light emitting portion that is not necessary for inspection can be eliminated, which contributes to power saving. The article 20 to be inspected is transported so that the central axis thereof coincides with the central axis of the arch-shaped lighting device. Therefore, since there is no interference between the moving direction of the article to be inspected and the illumination device, the design of the inspection device can be facilitated.

  Further, an imaging device 30 for imaging the surface of the article to be inspected is attached by a support tool 40 in the vicinity of the top of the arch-shaped lighting device. The imaging device 30 images the outer peripheral surface of the inspected article 20 that has passed through the arched illumination device 10 with a certain depression angle. Therefore, the imaging means 30 acquires an image of specularly reflected light such that the depression angle and the reflection angle on the surface of the inspected article match. On the other hand, if there is dirt or scratches on the surface of the article to be inspected, the light that hits it is diffusely reflected without regular reflection, so that only the image captured by the imaging device appears dark and is recognized as an abnormal location. it can.

  As another embodiment for diffusing light emission on the inner peripheral surface of the arch, as shown in FIG. 3, a diffuse reflector 18 on the inner peripheral surface of the arch is formed and directed toward the inner peripheral surface of the arch at the inner lower part of the arch. And the light-emitting diodes 12 arranged in this manner. The light emitted from the light emitting diode 12 is diffused by the diffuse reflector 18 on the inner peripheral surface of the arch and irradiates the surface of the inspection object 20. Furthermore, it is preferable to install the light diffusion plate 19 on the front surface of the light emitting diode 12 because the diffusion on the inner peripheral surface of the arch becomes more uniform.

It is a conceptual diagram of the external appearance inspection apparatus using the illumination device for external appearance inspection in this invention. It is a conceptual diagram which shows one embodiment of the illuminating device for external appearance inspection in this invention. It is a conceptual diagram which shows another embodiment of the illuminating device for external appearance inspection in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Illuminating device 12 ... Light emitting diode 14 ... Light diffusing plate 16 ... Arch 20 ... Article to be inspected 30 ... Imaging means

Claims (3)

In an illuminating device used for visual inspection of an article to be inspected having a specular reflection characteristic of a cylindrical shape or a circular arc shape that moves continuously in the axial direction,
The lighting device has an arch shape, and is arranged so that a central axis thereof coincides with a central axis of the article to be inspected,
On the inner peripheral surface of the arch, a diffused light source having a light emitting surface shape that emits a light beam that passes through the lens center of the camera after being regularly reflected at each point of the inspection target region on the outer peripheral surface of the inspected article An illumination device for visual inspection characterized by the above. The diffuse light emission source is a light emitter disposed on the inner peripheral surface of the arch in the axial direction of the arch, and a light diffusing plate installed between the light emitter and the article to be inspected. The illumination device for visual inspection according to claim 1. 2. The diffuse light source is a light emitter disposed on an inner lower surface of the arch toward an inner peripheral surface of the arch, and a diffuse reflector formed on the inner peripheral surface of the arch. The illumination device for external appearance inspection as described.

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