JP3142494U - Dark field illumination detector - Google Patents

Abstract

Disclosed is a dark field illumination detection device that can easily detect a surface defect by adjusting an irradiation angle of a light source.
A cavity 1 whose inner surface is a light-absorbing surface 11, an opening 12 is provided at an upper portion thereof, a band 2 disposed in an annular shape on the light-absorbing surface 11 of the cavity 1, and a band 2 A plurality of light emitting devices 3 that are arranged and electrically connected to each other and a position that corresponds to the opening 12 of the cavity 1, and collects and forms an image of the light reflected or refracted inside the cavity 1. A plate 4 is provided.
[Selection] Figure 2

Description

  The present invention relates to an optical device, and more particularly to a dark field illumination detection device for detecting surface defects.

  Dark field illumination technology is widely used for inspection of devices or objects having a specular structure. For example, it is used for detecting surface defects of jewelry and semiconductor devices. In the dark field illumination technique, a light source is arranged, and a light beam emitted from the light source is directly irradiated onto an object to be inspected. An image is formed by reflecting or refracting the irradiated light beam based on the diffuse reflection or refraction property of the light beam of the detection target object. This image is inspected for defects on the surface.

  The prior art will be described below with reference to the drawings. FIG. 1 is a cross-sectional view illustrating a conventional dark field illumination detection apparatus. As shown in FIG. 1, the dark field illumination detection apparatus according to the prior art includes a cavity 10 whose inner surface is a light absorbing surface. An opening 101 is provided at the top end of the cavity 10, and the plate 20 is disposed at a position corresponding to the opening 101. A light emitting device 30 is disposed at the bottom of the cavity 10, and a plurality of light guide tubes 40 are disposed around the light emitting device 30. The light guide tube 40 guides light from the position of the light emitting device 30 to the inspection target object 50. The inspection target object 50 is disposed on the light shielding plate 102, the light beam emitted from the light emitting device 30 is blocked by the light shielding plate 102, and the inspection target object 50 is directly irradiated by the light beam guided to the light guide tube 40. Due to the diffuse reflection or refraction characteristics of the light beam of the inspection object 50, the light beam is condensed on the plate 20 and imaged. From this image, it is determined whether the surface is free from defects.

The dark field illumination detection device according to the prior art uses the light guide tube 40 as a light guide path and provides a light source of the dark field illumination detection device. Since the inspection target object 50 is directly arranged on the light shielding plate 102, when inspecting a surface defect at a different position, it is necessary to intentionally change the position, which affects the inspection efficiency. In addition, the method of indirectly irradiating the light guide tube 40 as a light guide path often results in insufficient image formation due to the diffuse reflection or refraction of light rays due to the lack of light rays. Has been affected. Therefore, a method for improving the above problems has been demanded.
JP-A-8-167638

  An object of the present invention is to provide a dark field illumination detection device that can easily detect surface defects by adjusting the irradiation angle of a light source.

  In order to achieve the above object, the present invention provides a dark field illumination detection apparatus. The dark field illumination detection device of the present invention has a cavity whose inner surface is a light absorption surface, an opening is provided in the upper part, a band disposed in a ring shape on the light absorption surface of the cavity, and a band disposed on the band A plurality of light-emitting devices electrically connected to each other, and a plate that is disposed at a position corresponding to the opening of the cavity, collects the light reflected or refracted inside the cavity, and forms an image. . The light beam applied to the object to be inspected is reflected or refracted and collected on a plate on the opening of the cavity to form an image. From this image, it is determined whether the surface is free from defects.

  The dark field illumination detection device of the present invention can adjust the irradiation angle of the light source, and it is not necessary to change the position of the object to be inspected, thereby improving the inspection efficiency. Further, since the amount of light emitted from the light source is sufficient, it is possible to form an image sufficiently and obtain a highly accurate inspection result.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a perspective view illustrating a dark field illumination detection apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a dark field illumination detection apparatus according to an embodiment of the present invention. FIG. 5 is a cross-sectional view illustrating a light absorption surface according to another embodiment of the present invention. As shown in FIGS. 2, 3, and 5, the dark-field illumination detection device according to an embodiment of the present invention includes a cavity 1 whose inner surface is an absorption surface 11. The light absorption surface 11 is made of a black material, and the material in the present embodiment is a black pigment. The light absorption surface 11 may be made of a black cloth as shown in FIG. The cavity 1 is provided with an opening 12 at the top, and the band 2 is arranged in an annular shape on the light absorption surface 11 inside. A plurality of light emitting devices 3 are arranged in the band 2, and the light emitting devices 3 in the present embodiment are light emitting diodes, and the light emitting diodes on the band 2 are electrically connected to each other. A plate body 4 is disposed at a position above the opening 12 of the cavity 1. The plate body 4 blocks the light beam irradiated in the cavity 1 and simultaneously forms an image of the light beam reflected in the cavity 1 on the plate body 4.

  Please refer to FIG. The dark field illumination detection apparatus of the present invention is used for inspecting an inspection object 5 having a mirror surface or a curved surface. For example, like the semiconductor device having a jewel or a mirror surface, the inspection target object 5 has a characteristic of diffuse reflection or refraction of light rays. The inspection target object 5 is hung inside the cavity 1. Electric power is supplied to the band 2 around the inspection target object 5, and light rays emitted from the plurality of light emitting devices 3 on the band 2 directly irradiate the surface of the inspection target object 5. Due to the diffuse reflection or refraction characteristics of the light beam of the inspection object 5, the light irradiated on the inspection object 5 is reflected or refracted and reflected or refracted other than the light absorbed by the light absorption surface 11 in the cavity 1. The light rays (indicated by arrows) are focused on the plate 4 on the opening 12 of the cavity 1 and imaged. From this image, it is determined whether the surface is free from defects.

  FIG. 4 is a perspective view illustrating a dark field illumination detection apparatus according to another embodiment of the invention. As shown in FIG. 4, in the dark field illumination detection apparatus according to another embodiment of the present invention, in the shape of the band 2, the one band 2 is annularly arranged on the light absorption surface 11 of the cavity 1. In addition to the above, the annular band 2 can be used. An annular band 2 is disposed on the light absorption surface 11 in the cavity 1 with a space therebetween, and a plurality of light emitting devices 3 on the same band 2 are electrically connected to each other. By controlling the light emission of the light emitting device 3 on the different band 2, it is determined whether or not there is a defect on the different surface by irradiating the inspection target object 5 with light rays of different angles.

  Although the present invention discloses preferred embodiments as described above, these are not intended to limit the present invention in any way, and anyone skilled in the art is within the spirit and scope of the present invention. Various changes and modifications can be made. Therefore, the scope of protection of the present invention is based on the contents specified in the claims of the utility model.

It is sectional drawing which shows the dark field illumination detection apparatus by a prior art. 1 is a perspective view illustrating a dark field illumination detection device according to an embodiment of the present invention. It is sectional drawing which shows the dark field illumination detection apparatus by one Embodiment of this invention. It is a perspective view which shows the dark-field illumination detection apparatus by another embodiment of this invention. It is sectional drawing which shows the light absorption surface by another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cavity 2 Band 3 Light-emitting device 4 Plate 5 Object to be inspected 11 Absorbing surface 12 Opening

Claims (7)

A cavity whose inner surface is a light-absorbing surface and has an opening at the top;
A band disposed annularly on the light-absorbing surface of the cavity;
A plurality of light emitting devices disposed on the strip and electrically connected to each other;
A dark-field illumination detection apparatus comprising: a plate that is disposed at a position corresponding to the opening of the cavity and collects and focuses a light beam reflected or refracted inside the cavity.   The dark field illumination detection apparatus according to claim 1, wherein the light emitting device is a light emitting diode.   The dark field illumination detection apparatus according to claim 1, wherein the light absorption surface is made of a light-absorbing pigment.   The dark field illumination detection apparatus according to claim 3, wherein the pigment is a black pigment.   The dark field illumination detection apparatus according to claim 1, wherein the light absorption surface is made of a light-absorbing cloth.   The dark field illumination detection apparatus according to claim 1, wherein the cloth is made of a black cloth.   The dark field illumination detection device according to claim 1, wherein the belt is a plurality of the belts and has an annular shape.

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