KR20160078799A

KR20160078799A - Apparatus for detecting defect

Info

Publication number: KR20160078799A
Application number: KR1020140189002A
Authority: KR
Inventors: 배호문
Original assignee: 주식회사 포스코
Priority date: 2014-12-24
Filing date: 2014-12-24
Publication date: 2016-07-05

Abstract

The present invention relates to a defect detecting apparatus capable of detecting an under-pickling defect occurring on a parent metal. The defect detecting apparatus according to the present invention comprises: a camera, arranged in an upper part of a parent metal, for photographing a surface of the parent metal; and a light source means, arranged between the parent metal and the camera, for irradiating light in multiple directions for a photographing area of the parent metal. According to the present invention, the surface of the parent metal can be photographed by the camera, and an under-pickling defect can be detected more easily via a photographed image.

Description

{APPARATUS FOR DETECTING DEFECT}

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a defect inspection apparatus, and more particularly, to a defect inspection apparatus capable of detecting fine defects occurring in a base material.

Generally, a base material produced by a steel process is cooled to a room temperature at a high temperature of about 1100 ° C, and the scale reacts with oxygen in the cooling process. After the hot rolling process, the scales generated on the surface are removed through a pickling process. However, when the scales generated on the surface during the pickling process can not be completely removed, it is referred to as a misplaced defect.

If there are any defects in the product produced after cold rolling the base material, there is a problem with the quality of the product. Therefore, the surface quality inspection is carried out before shipping the base material. Until now, the worker has been visually inspected, but the size of the three defects is as small as about 20 to 100 탆, which makes it difficult for a worker to visually inspect the work.

In order to overcome these problems, a method of inspecting three defects by photographing the surface of the base material with a camera can be utilized. 1 (a), the surface roughness R of the base material P is expressed in the image as shown in FIG. 1 (a). In this case, (D) defects. 1 (b), the surface roughness R of the base material P is present in a small portion or a small portion where the surface roughness R is large. When the surface image is acquired, the surface roughness R of the base material P There is a problem that it is difficult to distinguish between the defect (R) and the defect (D).

It is an object of the present invention to provide a defect inspection apparatus which is capable of inspecting three defects through a photographed image by photographing a surface of a base material with a camera.

It is another object of the present invention to provide a defect inspection apparatus capable of reducing the influence of the surface roughness of a base material and easily detecting three defects.

According to another aspect of the present invention, there is provided a defect inspection apparatus comprising: a camera disposed at an upper portion of a base material to photograph a surface of the base material; a camera disposed between the base material and the camera, And light source means for emitting light in a plurality of directions with respect to the light source means.

The light source unit may include a reflective member provided with a hollow portion therein and reflecting the light emitted to the inside in a plurality of directions, and a light source unit disposed on the reflective member and irradiating light to the reflective member.

The reflecting member may be formed in a hemispherical shape having an interior hollow and may be formed to reflect light irradiated to the inside.

The reflective member may further include a camera coupling portion formed to penetrate the center portion and coupled to the camera.

The light source unit may be installed at an end of the reflective member.

The light source may be a linear light source disposed along the circumferential direction of the end of the reflective member.

According to the defect inspection apparatus of the present invention, the surface of the base material can be photographed by a camera, and three defects can be detected more easily through photographed images, thereby improving the work efficiency.

According to the present invention, since the surface of the base material is configured to be irradiated with light in a plurality of directions, the influence of the surface roughness of the base material can be reduced in the image captured by the camera, It is possible to obtain an effect of improving the quality of the image.

1 (a) is a photograph schematically showing a surface of a base material photographed through a general camera,
FIG. 1 (b) is a schematic view schematically showing the position of the grooves in the surface roughness of the base material,
FIG. 2 is a schematic view schematically showing a configuration of a defect inspection apparatus according to an embodiment of the present invention,
FIG. 3 is a schematic view schematically showing a direction in which light is illuminated in a defect inspection apparatus according to an embodiment of the present invention,
4 is a photograph showing the surface of a base material by using a defect inspection apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to facilitate understanding of the features of the present invention, a defect inspection apparatus according to an embodiment of the present invention will be described in detail.

It should be noted that, in order to facilitate understanding of the embodiments described below, reference numerals are added to the constituent elements of each of the accompanying drawings, and the same constituent elements are denoted by the same reference symbols whenever possible . In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, a specific embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a schematic view schematically showing a configuration of a defect inspection apparatus according to an embodiment of the present invention, and FIG. 3 is a schematic view schematically showing a direction in which light is illuminated in the defect inspection apparatus.

2 and 3, a defect inspection apparatus 1 according to the present invention includes a camera 10 for photographing a surface of a base material P, And a light source 20 for irradiating light.

Preferably, the camera 10 is of a type capable of photographing a predetermined area, and the photographing size of one pixel is set to have a resolution of 5 탆. It is preferable that the lens of the camera 10 is provided so as to be able to be replaced in correspondence with the photographing distance between the base material P and the camera 10. Of course, the performance of the camera 10 is not limited thereto, and various cameras may be applied depending on the material, size, and usage environment of the parent material P for determining the three-dimensional defects.

The light source unit 20 includes a reflecting member 30 capable of reflecting the light L to be emitted in a plurality of directions and a reflecting member 30 disposed on the reflecting member 30, And a light source unit 40 for irradiating the light.

The reflection member 30 is provided in the form of a hemispherical hollow, that is, in the form of a dome. The reflection member 30 reflects the light L emitted to the inside thereof, passes through the center portion, The surface of the base material P is photographed. A camera fastening part 32 is provided at the center of the reflective member 30.

The reflective member 30 may be made of a material capable of reflecting light from the entire body or may be made of a material capable of reflecting light only to the inner side.

The light source unit 40 is installed at an end portion 31 of the reflection member 30 and irradiates light L in a plurality of directions inside the reflection member 30. The light source unit 40 may be disposed as a linear light source along the circumferential direction of the end portion 31 of the reflective member 30.

For example, the light source unit 40 may be provided in a donut shape and may be installed at the end 31 of the reflective member 30, or the light source unit 40 may include a light source, Or may be provided in plural along the circumferential direction of the end portion 31 of the reflecting member 30. It is preferable that the light source unit 40 irradiates light L instantaneously like a flash for a camera and emits light only for about 5 to 20 microseconds.

3, light L emitted in a plurality of directions from the light source unit 40 is irradiated to the inside of the reflection member 30, light L emitted to the inside is reflected, And the surface of the base material P is irradiated. That is, the light L is irradiated to the surface of the base material P in a plurality of directions, and the shade due to the surface roughness can be minimized when the surface of the base material P is photographed by the camera 10.

4 is a photograph showing the surface of a base material by using a defect inspection apparatus according to an embodiment of the present invention.

Referring to FIG. 4, an image photographed using the defect inspection apparatus 1 of the present invention is represented by 256 gray levels of 8 bits. In the photographed image, the average brightness of the surface of the base material P corresponds to about 100 levels, and the brightness of the deep (D) defect corresponds to about 40 levels.

That is, when the surface of the base material P is photographed by the camera 10, the light source means 20 irradiates the surface of the base material P with light L in a plurality of directions, (D) defects were clearly detected in dark color.

With this configuration, it is possible to minimize the dark region appearing due to the surface roughness of the base material when the surface of the base material is photographed by the camera, by the light irradiated in a plurality of directions, thereby making it possible to more clearly display three defects, Three defects can be detected.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is to be understood that various changes and modifications may be made without departing from the scope of the appended claims.

P: base metal R: surface roughness
D: Mysanese L: Light
1: defect inspection device 10: camera
20: light source means 30: reflective member
40:

Claims

A camera disposed on an upper portion of the parent material and photographing a surface of the parent material; And
Light source means disposed between the base material and the camera, the light source means irradiating light to a photographing region of the base material in a plurality of directions;
And the defect inspection device.

The method according to claim 1,
Wherein the light source means comprises:
A reflecting member provided with a hollow portion therein and reflecting the light emitted to the inside in a plurality of directions; And
A light source unit disposed on the reflection member, the light source unit emitting light to the reflection member;
And a defect inspection unit for detecting the defect.

3. The method of claim 2,
Wherein the reflective member comprises:
Wherein the light source unit is provided in a hemispherical shape with an empty interior, and reflects light irradiated to the inside.

The method of claim 3,
Wherein the reflective member comprises:
A camera fastening part formed through the center part and fastened to the camera;
Further comprising a deflector for deflecting the defect.

The method of claim 3,
The light source unit includes:
Wherein the reflection member is provided at an end of the reflection member.

The method of claim 3,
The light source unit includes:
And a linear light source disposed along a circumferential direction of an end of the reflective member.