JPS63271143A - Device for observing body to be inspected - Google Patents

Abstract

PURPOSE:To easily detect abnormality such as a flaw on the surface of a body to be inspected, by illuminating said body to be inspected, by a diffused light through a diffusion member interposed between a light source and the body to be inspected. CONSTITUTION:When a body to be inspected 3 is transferred to the lower part of a television camera 1, a placing table 6 is stopped, and by a mobile mechanism 8, a diffusion member 4 which consists of a material for allowing a light beam to transmit through and diffusing it,and has a dimension by which a light beam from a light source 5 does not irradiate directly the body to be inspected 3 by covering the body to be inspected 3 is allowed to descend, and the body to be inspected 3 is covered. An illuminating light from the light source 5 is diffused in every direction, when it transmits through the diffusion member 4, a part of this diffused light reaches the surface of the body to be inspected 3, and the surface of the body to be inspected 3 is illuminated indirectly and uniformly. Also, since the diffusion member 4 covers the body to be inspected 3, the illuminating light from the light source 5 does not reach directly the body to be inspected 3, it does not occur that the surface of the body to be inspected shines partially.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an optical observation device for a subject.

(Prior art) An object to be inspected as shown in FIG.
When inspecting the presence or absence of scratches 3a on the surface of a product, it was generally done visually, but in order to perform automatic inspection on an automatic production line or to meet various other demands, it is now possible to inspect the surface using a television camera, etc. There is a desire to be able to perform inspections by processing images using observation equipment. When observing a wL specimen using observation equipment in this manner, it is necessary to irradiate the surface of the specimen with light from a light source.

(Problems to be Solved by the Invention) If the shape of the object to be examined is hemispherical as shown in Fig. 4, and the surface is not a matte surface (for example, a shiny metallic surface), The illumination light reflected on the surface of the object 3 directly enters the observation equipment, causing that part to shine, reducing the contrast of the image obtained by the observation equipment and overlooking scratches on the surface of the object 3. Inspection is not possible.Such problems cannot be solved even if the illumination format is changed to epi-illumination, point light source illumination, or even ring-shaped light source illumination.

The present invention has been made in order to solve such conventional problems, and provides an observation device for an object that undergoes image processing, making it possible to highlight abnormal parts such as scratches on the surface of the object. The purpose is to

(Means for Solving the Problems) The present invention provides an object observation device for observing the surface of an object using an observation device such as a television camera.
The present invention is characterized in that a diffusion member covering the subject is interposed between the light source and the subject, and the subject is illuminated by diffused light passing through the diffusion member.

(Function) The illumination light from the light source passes through the diffusion member and becomes diffused light, and the subject is uniformly illuminated by this diffused light. Since the diffusion member covers the subject, the illumination light from the light source will not be directly irradiated onto the subject (and the surface of the subject will not be partially illuminated, so there will be no scratches on the subject's surface). Abnormal parts can be clearly observed.

(Example) Hereinafter, an example of the object observation device according to the present invention will be described with reference to the drawings.

In FIG. 1, it is assumed that a mounting table 6 on which the subject 3 is placed is provided, for example, on a moving mechanism such as a conveyor in a production line, and an imaging lens 2 is provided above a predetermined position of the mounting table 6. A television camera 1 is arranged facing downward. The television camera 1 constitutes an observation device that observes the surface of the subject 3. The format of the television camera 1 is not particularly limited, and may be of a general format using, for example, a solid-state image pickup device such as a COD, an image pickup tube, or the like. A cylindrical light diffusing member 4 is provided below the television camera 1 so as to be movable up and down by a moving mechanism 8 . A light source 5 for illuminating the subject 3 is arranged on the side of the light diffusing member 4 . That is, a diffusion member 4 that covers the subject 3 is interposed between the light source 5 and the subject 3.

The shape of the subject 3 is hemispherical in the illustrated example,
When a conventional general observation device is used, the surface of the object 3 has an unfavorable shape that makes it extremely susceptible to light. In addition to the hemispherical shape described above, the shape of the subject 3 may also be a conical shape, a quadrangular pyramid shape, an ellipsoidal shape, etc., which gradually increase in size from the top toward the mounting table 6. Alternatively, it may be made of a material that reflects light very well, such as a metallic lustrous material.

The diffusion member 4 is made of a material that transmits and diffuses light, such as paper,
Made from celluloid, plastic, frosted glass, etc. Although the shape of the diffusion member 4 does not necessarily have to be cylindrical, it covers the subject 3 and allows the light from the light source 5 to illuminate the subject 3 so that the subject 3 can be illuminated with almost uniform brightness. It needs to be large enough that it won't be exposed to direct light.

Now, the diffusion member 4 is raised by the moving mechanism 8 in a prone position, and the subject 3 is placed on the mounting table 6 and transferred. When the subject 3 is transferred to a predetermined position below the television camera l, the mounting table 6 is stopped and the moving mechanism 8
The diffusing member 4 is lowered to cover the subject 3 with the diffusing member 4.

When the illumination light from the light source 5 passes through the diffusion member 4, it is diffused in all directions, and a portion of this diffused light reaches the surface of the subject 3 and illuminates the surface of the subject 3 indirectly and uniformly. In addition, since the diffusion member 4 covers the subject 3, the illumination light from the light source 5 does not directly reach the subject 3, so that the surface of the subject 3 does not become partially illuminated.

Here, consider light that is diffused from the upper and lower ends of the diffusion member 4 and reaches the surface of the subject 3, and is further reflected on the surface of the subject 3 and reaches the television camera 1 through the imaging lens 2. When the subject 3 is hemispherical as in the illustrated example, the light diffused from the upper end Pa of the diffusing member 4 is reflected at a position Oa near the center of the upper end of the subject 3, and then reaches the television camera 1 where it is effective. It becomes a luminous flux. On the other hand, the light diffused from the lower end pb of the diffusion member 4 is reflected by the lower end outer circumference Ob of the subject 3 and then reaches the television camera 1, where it becomes an effective light beam. As a result, as shown in FIG. 2, the area Za in the center of the subject 3 and the diffusion member The region zb of the lower edge of the outer periphery of the object 3 is lower than the position ob on the surface of the object 3 where the light from the lower end pb of 4 is incident.
Almost no illumination light reflected by the television camera 1 enters the television camera 1 and becomes dark, so the areas Za and Zb become non-detection areas. On the other hand, the X area between the area Za and the area zb is a detection area uniformly illuminated with diffused light, and if there is an abnormality such as a scratch in this X area, the detection area from the abnormal part such as the scratch will be detected. Since almost no reflected light enters the television camera 1, abnormal areas such as scratches become dark and are clearly distinguished from other areas, making it possible to easily detect abnormal areas.

When the observation is completed as described above, the subject 3 is transferred by transferring the mounting table 6 while the diffusion member 4 is raised by the moving mechanism 8.

In the modified embodiment shown in FIG. 3, the mounting part 7 for the subject 3 is formed on the mounting table 6 so as to protrude upward, and the vertical dimension of the diffusion member 4 is made relatively long. Further, the diffusion member 4 is placed on the upper surface of the mounting table 6. According to this embodiment, the position of the upper end Pa of the diffusion member 4 is raised;
On the other hand, the position of the lower end pb of the diffusion member 4 is lower than the lower end of the subject 3. As a result, the position Oa on the surface of the subject 3 where the diffused light from the upper end Pa of the diffusion member 4 is reflected and reaches the television camera 1 approaches the center of the subject 3,
On the other hand, a position O on the surface of the subject 3 where the diffused light from the lower end pb of the diffusion member 4 is reflected and reaches the television camera 1.
As b approaches the lower end of the subject 3, the non-detection areas Za and Zb explained with reference to FIG. 2 become narrower, and conversely,
There is an advantage that the detection area X is wide.

Note that the shape of the object to be examined is not limited to the shape that increases in size from the top to the bottom as described in the embodiment, and can be applied to objects of any shape.

(Effects of the Invention) According to the present invention, a diffusion member covering the subject is interposed between the light source and the subject, and the subject is illuminated by diffused light passing through the diffusion member. can be illuminated with uniform brightness, the surface of the object to be examined will not be partially illuminated, and therefore abnormalities such as scratches on the surface of the object can be easily detected.

[Brief explanation of drawings]

FIG. 1 is a partially sectional front view showing an embodiment of the object observation device according to the present invention, FIG. 2 is a plan view for explaining the detection area of the object in the same embodiment, and FIG. FIG. 4 is a partially sectional front view showing another embodiment of the object observation device according to the present invention, and FIG. 4 is a front view showing an example of the object. 1. Television camera, 3. Subject, 4. Diffusion member, 5. Light source.

Claims (1)

[Claims] In an observation device for an object that irradiates light from a light source onto the surface of the object to be observed and observes the surface of the object with an observation device such as a television camera, there is no space between the light source and the object. 1. An observation device for an object, characterized in that a diffusion member covering the object is interposed, and the object is illuminated by diffused light passing through the diffusion member.