JPH06109644A - Tube inner face examination device with ccd camera - Google Patents

Abstract

PURPOSE:To provide a visual examination device with a CCD camera, for the inner wall of a tube, which allows significant improvement in workability and less examination processes by lighting the wall surface to be examined brightly and evenly over an extended area. CONSTITUTION:A CCD camera 1 with built-in light source is used, and a reflection plate 3 is provided in front of its lens. The light emitted from the light source 2, built in the CCD camera 1, is reflected on the inner wall surface of a tube 5, so that a wider wall surface is evenly illuminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for visually inspecting the inner surface of a tube, and more particularly to an apparatus for inspecting the inner surface of a tube using a CCD camera with a built-in light source.

[0002]

2. Description of the Related Art A conventional pipe inner surface visual inspection method is shown in FIGS. All of these methods are based on the television system. Only the camera head of the television is brought into the tube, and the image in the tube is projected on the external TV monitor for visual inspection. Below, only the camera head portion brought into the tube will be described.

First, FIG. 3 shows a fiberscope 6 or a borescope having the same principle as a so-called gastroscope. 4 shows the CCD camera 1, but since it does not have a built-in light source, a separate light 8 is used to illuminate the inside of the tube.
It is inserted in front of or behind the camera 1. Also in FIG.
Shows the case of the CCD camera 1 with a built-in light source which has been recently used.

[0004]

However, in these methods for visually inspecting the inner surface of the tube, first, in the case of FIG. 3, the focal length is short because of the same principle as the gastric camera, and therefore the camera 6 is placed close to the inner wall surface of the tube. In addition, the effective inspection visual field 7 is extremely limited due to the narrow visual field. Therefore, it is necessary to rotate the pipe 5 to be inspected in the circumferential direction,
Alternatively, it is necessary to rotate the scope 6 itself along the inner wall surface of the tube, and the workability is extremely poor.

In the case of FIG. 4, a light 8 for illumination is put in the tube separately from the camera 1, but when this is in front of the CCD camera 1, the light directly enters the camera 1 and causes halation, Also, the light 8 is a CCD
When it was behind the camera 1, the CCD camera 1 itself got in the way, and the shadow was shaded so that the desired image could not be obtained.

Further, in the case of the CCD camera 1 shown in FIG.
Although the workability was greatly improved because the light source 2 was built in, most of the light that radiated the inner surface of the tube 5 was reflected forward because the illumination light emitted from the camera 1 side, I won't come back. This results in very dark lighting,
I couldn't do enough inspection.

The present invention has been made in order to solve such a problem, and improves the illuminance of the surface to be inspected to expand the visual inspection visual field, thereby improving the workability of the inspection and reducing the number of man-hours. The purpose is to provide a visual inspection device.

[0008]

To achieve this object, in the present invention, a CCD camera with a built-in light source is used, and a reflector is attached in front of the lens. Then, the light from the light source built into the CCD camera is reflected on the inner wall surface of the tube by this reflecting plate, so that the entire visual field in the circumferential direction of the inner wall surface of the tube can be visually inspected at one time.

[0009]

Since this inspection apparatus uses a CCD camera with a wide-angle lens, the inspection field of view that can be viewed at one time is the entire circumference of the inner surface of the tube, so there is no need to rotate the tube or the camera.
Since the CCD camera has a built-in light source, there is no need to insert a light separately, and workability is extremely good.

Further, since a reflection plate is provided in front of the CCD camera to reflect the illumination light of the light source built in the camera to the inner surface of the tube, sufficient illuminance can be secured for visually inspecting the inner surface of the tube, and the illumination in the circumferential direction The entire field of view is wide and can be visually inspected at once.

[0011]

1 is a side view of a pipe inner surface inspection apparatus according to the present invention, and FIG. 2 is a bird's eye view thereof. The structure and operation will be described below with reference to FIG.

First, the attachment 4 is attached to the CCD camera 1.
While the reflector 3 is fixed by this, the support bar of the reflector 3 is slid back and forth to fix the reflector 3 and the CCD.
Adjust the distance to the camera 1. Further, the reflection plate 3 can be pulled out from the attachment 4 and replaced with another reflection plate. In this embodiment, a convex mirror reflector is used. Further, since the CCD camera 1 is used, a circular inspection visual field is normally obtained, but since the reflector 3 is attached, a circular hollow portion occurs in the center, and the visible inspection visual field has a donut shape. However, in the circumferential direction of the inner surface of the tube 5, the entire field of view is visible.

Next, the illumination light emitted from the built-in light source 2 of the CCD 1 is reflected by the reflection plate 3 of the convex mirror and uniformly illuminates the inner surface of the tube 5, so that a donut-shaped inspection field having a uniform brightness in a wide range. And excellent workability,
The number of inspection steps can be greatly reduced.

When the inner diameter of the tube 5 to be inspected is changed, the reflection angle of the illumination light and the inspection field of view are also changed. Therefore, the size B of the reflecting plate 3 should be changed to match the inner diameter of the tube 5. Then, the position of the reflection plate 3 is moved by sliding inside the attachment 4, and the reflection plate 3 and the CCD camera 1 are moved.
Adjust the distance between and to obtain the optimum illuminance and inspection field range. In FIG. 1, if the distance A between the CCD camera 1 and the reflection plate 3 is increased, the range of the inspection visual field is expanded.
In order to maintain the illuminance in the field of view and its uniformity, it is desirable that the distance A is 5 times or less the size B of the reflector 3. If the size B of the reflection plate 3 is small, the amount of reflected light is reduced and the illuminance on the inner surface of the tube 5 is reduced. In particular, it should not be smaller than the outer diameter of the CCD camera 1. However, since the size of the reflection plate 3 is not strictly limited, it is not necessary to replace the reflection plate 3 each time the inner diameter of the tube 5 changes, unless the inner diameter of the tube 5 changes significantly.

In this embodiment shown in FIG. 1, a convex surface having a shape close to a spherical surface is used for the reflecting plate 3, but this is because of the light diffusivity.
This is because it is possible to obtain better characteristics than a flat surface. However, since sufficient illuminance can be obtained even on a flat surface, it is not necessarily a convex surface and may be a flat surface.

[0016]

As described above, the CC according to the present invention
In the tube inner surface inspection device using the D camera, since the inspection field of view can be obtained 360 ° in the circumferential direction, it is not necessary to rotate the tube or the camera, and the reflector is provided in front of the camera to provide a wide inspection field and a bright image. Since the illuminance can be obtained, there is a remarkable effect in improving workability and reducing the number of inspection steps.

[Brief description of drawings]

FIG. 1 is a side view of a pipe inner surface inspection apparatus using a CCD camera according to the present invention.

FIG. 2 is a bird's-eye view of the pipe inner surface inspection device shown in FIG.

FIG. 3 is an explanatory diagram of a conventional pipe inner surface inspection method 1 (using a fiberscope).

FIG. 4 is an explanatory diagram of a conventional pipe inner surface inspection method 2 (using a CCD camera).

FIG. 5 is an explanatory diagram of a conventional tube inner surface inspection method 3 (using a CCD camera with a built-in light source).

[Explanation of symbols]

1 ... CCD camera 2 ... Light source 3 ... Reflector 4 ... Attachment 5 ... Tube 6 ... Fiberscope 7 ... Inspection field of view 8 ... Light

Front page continuation (72) Inventor Suzou Yamamoto 6-9 Takaracho, Kure City, Hiroshima Prefecture Babcock Hitachi Ltd. Kure Factory (72) Minato Hiratani 6-9 9 Takaracho, Kure City Hiroshima Prefecture Babcock Hitachi Ltd. Kure Factory Within

Claims (1)

[Claims] 1. An apparatus for visually inspecting an inner wall surface of a pipe by using a CCD camera with a built-in light source, wherein the CC with a built-in light source is used.
A CC provided with a reflecting plate for reflecting the light from the light source to the inner wall surface of the tube in front of the lens of the D camera.
Pipe inner surface inspection device with D camera.