JP2004198608A - Device, reflector, and method for in-tube photography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-tube photographing device capable of photographing a distinctive image. <P>SOLUTION: The in-tube photographing device is so constituted that lighting units 5 and 7 irradiate a tube 100 to be photographed which has its end made open with illumination light from the outside of the opening end to the inner side of the tube. The inner side of the tube 100 to be photographed which is irradiated with the illumination light is photographed by photographing units 4, 6, and 9 from the outside of the opening end. At this time, the illumination light is reflected to the opening end side by a reflector 13 which is provided more on the tube inner side of the tube to be photographed than areas which can be photographed by the photographing units 4, 6, and 9. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an in-pipe photographing apparatus for photographing a photographing target pipe having an opening at an end from the outside of the opening end, such as an industrial processing pipeline, a reflector used for in-pipe photographing, and an in-pipe photographing method.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is the following apparatus as an in-pipe photographing apparatus for photographing a photographing target tube having an opening at an end portion from the outside of the opening end. The in-pipe photographing apparatus photographs the inside of the tube to be photographed from outside the opening end by the photographing device in a state where the illumination light is emitted from the outside of the opening end of the photographing tube toward the inside of the tube. The illuminator includes an illuminator tip formed of a light guide using an optical fiber, and a light source that supplies illumination light to the illuminator tip. The photographing device is composed of a photographing device distal end portion composed of an image guide using an optical fiber, and a photographing device main body (CCD or the like) for converting a light signal captured by the photographing device distal end portion into a video signal. The front end of the illuminator and the front end of the photographing device are housed and arranged in one flexible tube and integrated.
[0003]
There is a case where the imaging target tube is installed in a place where the imaging operator cannot directly work, such as under a high-pressure atmosphere. In such a case, photographing is performed as follows. That is, a transparent viewing window is provided on the outer wall of the installation room for the imaging target tube. The viewing window is provided at a position where the opening end of the tube to be photographed can be photographed from outside the window. Further, the illuminator tip and the photographer tip are disposed outside the installation room (outside the window). In this state, in-pipe imaging is performed by the imaging device in a state where illumination light is emitted from the illumination device toward the opening end of the imaging target tube through the window. As an illuminator, for example, see Patent Document 1.
[0004]
[Patent Document 1]
Japanese Patent Application No. 6-148527 [0005]
[Problems to be solved by the invention]
The conventional in-pipe photographing apparatus has a problem that a clear image cannot be photographed. This will be described below. In the use state described above, the distal end of the illuminator and the distal end of the imaging device must be arranged at a position (for example, a distance of about 10 mm) apart from the opening end of the imaging target tube. Under these conditions, when imaging the inside of a small-diameter (for example, an inner diameter of 5 mm to 6 mm) imaging tube, the illumination direction of the illumination light should be narrowed to selectively irradiate the illumination light into the imaging tube. However, it is difficult to efficiently irradiate the inside of the small-diameter imaging target tube that is spaced apart with the illumination light. For this reason, it was necessary to take a picture under insufficient brightness, which was the reason why a clear image could not be taken.
[0006]
Note that, when imaging a small-diameter imaging target tube that is spaced apart, it is necessary to reduce the imaging angle of view of a lens unit included in the imaging device. Due to its structure, the lens portion has such a characteristic that when the angle of view is reduced, the depth of focus is reduced. An image photographed with a small depth of focus has an apparently narrow focusable and visually recognizable area. For this reason, this also became a reason why clear images could not be taken.
[0007]
Therefore, a main object of the present invention is to enable clear images to be captured.
[0008]
[Means for Solving the Problems]
As a means for solving the above-described problems, the present invention provides an illuminator that irradiates illumination light from an outside of the opening end toward the inside of the imaging target tube having an opening at an end, and the imaging device illuminated by the illumination light. A photographing device for photographing the inside of the target tube from the outside of the opening end thereof, and a reflection disposed to a position farther from the photographable region of the photographing tube than the photographable region of the photographing tube to reflect the illumination light toward the opening end side. And an in-pipe photographing device.
[0009]
This makes it possible to irradiate the photographable area with the reflected illumination light reflected by the reflector. When the reflector is not provided, the light reflected by the reflector passes through the photographable area and passes through the inner side of the tube, and does not contribute to illumination of the photographable area. The present invention conventionally makes it possible to reflect the light that does not contribute to illumination and illuminate the photographable area with the reflected light. Therefore, the illumination efficiency is increased and the clarity of the captured image is improved.
[0010]
The present invention is embodied in an in-pipe photographing apparatus having a configuration in which the illuminator and the photographing apparatus have the same illumination direction and the same photographing direction, and are arranged apart from the opening end of the photographing target tube. Is preferred. The in-pipe imaging apparatus having such a configuration has a feature that the clarity of a captured image is likely to be deteriorated. Therefore, if the present invention is applied to such an in-pipe photographing apparatus, the effect becomes remarkable.
[0011]
Note that, in addition to the above configuration, the present invention is configured such that the imaging angle of view of the imaging device is set to be narrow in order to match the imaging possible area with the in-tube area of the imaging target tube. It is preferable to implement the present invention in an in-pipe photographing apparatus having the following. The in-pipe photographing apparatus having such a characteristic has a characteristic that the width of an image region with high clarity is narrowed because the depth of focus is narrowed. Therefore, if the present invention is applied to such an in-pipe photographing apparatus, the effect will be more remarkable.
[0012]
In addition, the reflector is fitted to the opening end of the imaging target tube and has a through hole at the center of its axis, and a mounting ring body, and from the insertion hole of the mounting ring body to the axis of the imaging target tube. It is preferable to have a shaft extending along the inner side of the tube along the axis, and a reflector main body provided at the tip of the shaft. Then, the reflector main body can be accurately installed at the installation location without obstructing photographing and illumination light irradiation.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing an overall configuration of a tube photographing apparatus 1 according to an embodiment of the present invention. The in-pipe photographing apparatus 1 includes an eyepiece 2 and a flexible cable 3. The flexible cable 3 is composed of a metal flexible tube or the like.
[0014]
The proximal end of the flexible cable 3 is connected to the eyepiece 2. As shown in FIG. 2, an image guide fiber 4 and a light guide fiber 5 are inserted into the flexible cable 3. An objective lens 6 is attached to the distal end of the flexible cable 3. The objective lens 6 is arranged at a position facing the outside from the distal end of the flexible cable 3. The distal end of the image guide fiber 4 is arranged in a state where it is abutted on the objective lens 6. The distal end of the light guide fiber 5 is arranged at a position facing the outside from the distal end of the flexible cable 3. The light guide fiber 5 has the same illumination direction as the imaging direction of the objective lens 6.
[0015]
A light source device 7 and a video camera 8 are connected to the eyepiece 2. The light source device 7 supplies illumination light to the light guide fiber 5 via the eyepiece 2. The video camera 8 converts the photographic light captured via the objective lens 6 and the image guide fiber 4 into a video signal. A video tape recorder 9 and a television monitor 10 are connected to the video camera 8.
[0016]
With the above configuration, the in-pipe imaging device 1 performs the following basic imaging operation. That is, the outside of the distal end of the flexible cable 3 is illuminated by the light guide fiber 5. In this state, an image facing the objective lens 6 and located at its focal position is captured via the image guide fiber 4 and converted into a video signal by the video camera 8. Then, the obtained video signal is converted into a video and displayed on the television monitor 10. Further, the obtained video signal is recorded on a video tape by the video tape recorder 9.
[0017]
An imaging target tube 100 to be imaged by the in-pipe imaging device 1 is a small-diameter tube having an inner diameter of about 5 mm to 6 mm and having an opening at a tip thereof, and a setting room 101 in which a worker such as a high-pressure atmosphere cannot directly work. Are located in
[0018]
In order to perform in-pipe imaging of the imaging target pipe 100 having such structural features and installation environment, a viewing window 102 in which a transparent plate is fitted is provided on a side wall 101a of the installation chamber 101. The viewing window 102 is arranged at a position facing the open end 100a of the imaging target tube 100 so that the inside of the imaging target tube 100 can be imaged. Further, the viewing window 102 is disposed in a direction substantially orthogonal to the axial direction of the imaging target tube 100. The in-pipe photographing apparatus 1 is configured to photograph an imaging target tube 100 provided in the installation room 101 from the outside 110 of the installation room 101.
[0019]
In order to take an image of the imaging target tube 100 having the above-described structural features and installation environment, the in-tube imaging device 1 has the following configuration.
[0020]
The in-pipe photographing device 1 has a support plate 11 for supporting and fixing the distal end of the flexible cable 3. The support plate 11 has a mounting hole 12 into which the distal end of the flexible cable 3 is mounted. The mounting hole 12 is formed through the thickness of the support plate 11 and has a shape and a size that allow the distal end of the flexible cable 3 to be inserted and fixed.
[0021]
The support plate 11 configured as described above is attached to the outside of the side wall 101a so as to cover the viewing window 102. At this time, the support plate 11 is attached so that the mounting hole 12 is located outside the viewing window 102. The support plate 11 is attached such that the center axis of the mounting hole 12 coincides with the axial direction of the tube 100 to be imaged.
[0022]
The distal end of the flexible cable 3 is inserted and fixed in the mounting hole 12 of the support plate 11. Thus, the distal end of the flexible cable 3 is arranged outside the viewing window 102 so as to face the opening end 100 a of the imaging target tube 100. The flexible cable 3 is arranged such that the light receiving direction (imaging direction) of the image guide fiber 4 coincides with the axial direction of the imaging object tube 100. The focal position f of the objective lens 6 is set to a position at which a predetermined distance from the opening end 100a of the imaging object tube 100 that is located away from the imaging object 100 can be photographed. A specific example of the focal length of the objective lens 6 (separation distance between the objective lens 6 and the focal position f) that enables such photographing is about 30 mm.
[0023]
Since the objective lens 6 having the above characteristics is used to image the inside of the imaging target tube 100 having an inner diameter of about 5 mm to 6 mm, the angle of view of the objective lens 6 is set to a narrow angle of about 17 degrees. The depth of focus of the objective lens 6 having a narrow shooting angle of view of about 17 degrees is a very narrow width of about 5 mm.
[0024]
The in-pipe imaging device 1 includes a reflector 13. The reflector 13 includes a mounting ring body 14, a shaft body 15, and a reflector body 16. The mounting ring body 14 is externally fitted to the opening end 100a of the tube 100 by screwing. An insertion hole 14 a is provided at the center of the axis of the mounting ring body 14.
[0025]
The shaft body 15 is formed of a metal rod having a small diameter (several 100 μm to 1 mm). The shaft body 15 has a base end 15a and an extension 15b. The base end portion 15a and the extension portion 15b are formed in an L-shape. The base end 15a has a length equal to the radius of the mounting ring body 14. The extension portion 15b is set to be slightly longer (for example, about 15 mm) than a separation distance between the opening end 100a of the imaging target tube 100 and the focal position f of the objective lens 6. The shaft body 15 configured as described above is mounted on the mounting ring body 14 as follows. That is, the base end 15a is the outer surface of the mounting ring body 14 (the surface facing the outside of the open end 100a of the imaging target tube 100) in a state where the extension portion 15b is inserted into the insertion hole 14a of the mounting ring body 14. , Whereby the shaft 15 is mounted and fixed to the mounting ring 14. At this time, the shaft body 15 is fixed to the mounting ring body 14 such that the extending direction of the extending portion 15b matches the axial direction of the insertion hole 14a.
[0026]
The reflector body 16 is attached to the tip of the extension 15b. The reflector main body 16 has a hemispherical shape having a planar reflecting surface 16a. The reflector body 16 is attached to the shaft 15 by bonding the center of the reflection surface 16a to the tip of the extension 15b. The reflector main body 16 is mounted such that the reflection surface 16a is orthogonal to the axial direction of the imaging target tube 100. The reflection surface 16a has a size of about の of the inner diameter of the imaging target tube 100 (for example, about 2 mm). The reflecting surface 16a may have an outer surface shape of a circular body in addition to a flat shape. In the case of the outer surface shape of the conical body, the opening angle is preferably between 150 ° and 180 °.
[0027]
In the reflector 13 configured as described above, when the mounting ring body 14 is attached to the opening end 100a of the imaging target tube 100, the reflector main body 16 provided at the distal end of the extension portion 15b has the reflecting surface 16a. It is arranged toward the opening end 100a of the tube 100 to be imaged. At this time, the reflection surface 16a is arranged on the far side of the tube from the focal position f of the objective lens 6 (for example, about 15 cm from the focal position f, on the far side of the tube).
[0028]
In order to make the reflecting surface 16a of the reflector main body 16 a flat surface or an outer surface of a circular body, the reflected light is applied to the focal position f of the objective lens 6 located on the opening end side of the object tube 100 from the reflecting surface 16a. This is for efficient irradiation.
[0029]
In the in-pipe imaging device 1 having the above configuration, an example of an illuminator is configured by the light guide fiber 5 and the light source device 7, and an example of an imaging device is configured by the image guide fiber 4, the objective lens 6, and the video camera 8. Have been.
[0030]
When the inside of the imaging target tube 100 is imaged by the in-tube imaging device 1, the imaging region (the width of the depth of focus including the focal position f) of the imaging target tube 100 is illuminated by the illumination light illuminated from the light guide fiber 5 into the imaging target tube 100. ) Is irradiated. Under this illumination light, a photographable area is photographed. Illumination light that is effective for imaging is light that is reflected from an opening end 100a of the imaging target tube 100 to an imaging area and is emitted from the opening end 100a of the imaging target tube 100 toward the objective lens 6. . Light that is emitted toward the back of the tube without being reflected in the photographable area (hereinafter referred to as “passing light”) is generally not effective light for in-tube photographing.
[0031]
However, in the in-pipe photographing apparatus 1, by providing the reflector main body 16 on the far side of the tube from the photographable area, conventionally, a part of the passing light that is not effective in the in-pipe photographing is reflected toward the opening end side. . As a result, it is possible to make the passing light effective light for photographing, and accordingly, the illumination efficiency is increased and the clarity of the photographed image is improved.
[0032]
In general, an in-pipe imaging device is used for imaging a flaw in an in-pipe or an image of a circulating substance (liquid, gas, etc.) in an in-pipe, but using the in-pipe imaging apparatus 1 in which illumination efficiency is increased and clarity of a captured image is enhanced. By photographing these photographing objects, the photographing accuracy is remarkably improved.
[0033]
Since the imaging angle of view of the objective lens 6 is as narrow as 17 degrees, the in-pipe imaging apparatus 1 is characterized in that the depth of focus is very narrow, about 5 mm, and the viewable area is narrow. Therefore, increasing the illumination efficiency in such an in-pipe imaging device 1 is very effective in enabling high-clarity imaging of the entire narrow viewable region.
[0034]
In the above-described embodiment, the imaging target tube 100 is provided in the installation room 101, and the imaging is performed by the in-tube imaging device 1 from outside the installation room 101. However, the imaging target tube 100 is installed in the installation room 101. The present invention can also be implemented in an in-pipe photographing apparatus that photographs an unexamined photographing object tube 100. In short, if the present invention is applied to an in-pipe photographing device that photographs from a position separated from the photographing target tube 100, the effect can be sufficiently exhibited.
[0035]
Further, in the above-described embodiment, the present invention is implemented in the in-pipe photographing apparatus 1 that photographs the photographing tube 100 having an inner diameter of 5 mm to 6 mm, but the size of the photographing tube 100 is not limited to this. In short, the effects of the present invention can be sufficiently exerted by implementing the present invention in an in-pipe photographing apparatus for photographing an observation target tube having a small diameter such that the in-pipe photographing apparatus 1 cannot enter.
[0036]
【The invention's effect】
As described above, according to the present invention, it is possible to capture a clear in-tube image.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a tube photographing apparatus according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of a main part of the in-pipe imaging apparatus according to the embodiment;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 In-pipe imaging device 2 Eyepiece 3 Flexible cable 4 Image guide fiber 5 Light guide fiber 6 Objective lens 7 Light source device 8 Video camera 9 Video tape recorder 10 Television monitor 11 Support plate 12 Mounting hole 13 Reflector 14 Mounting ring 14a Insertion hole 15 Shaft 15a Base end 15b Extension 16 Reflector body 16a Reflection surface 100 Target tube 100a Open end 101 Installation room 101a Side wall 102 Viewing window f Focus position

Claims (6)

An illuminator that irradiates illumination light toward the inside of the tube from outside the opening end to the imaging target tube having an opening at the end,
A photographing device for photographing the inside of the photographing target tube illuminated by the illumination light from outside the opening end thereof,
A reflector that is arranged on the far side of the photographing target tube from the photographable area of the photographing device and reflects the illumination light toward the opening end side,
An in-pipe imaging device, comprising: The in-pipe imaging device according to claim 1,
The illuminator and the imaging device, the illumination direction and the imaging direction are equalized, and are arranged apart from the opening end of the imaging target tube,
An in-pipe imaging device, characterized in that: The in-tube imaging device according to claim 2,
The photographing device has a photographing angle of view set to be narrow in order to match the photographable region with the in-tube region of the photographing target tube.
An in-pipe imaging device, characterized in that: The in-pipe photographing device according to any one of claims 1 to 3,
The reflector is
A mounting ring body that is fitted to the opening end of the imaging target tube and has an insertion hole at the center of its axis,
A shaft body extending from the insertion hole of the mounting ring body toward the back of the tube along the axis of the imaging target tube;
A reflector body provided at the tip of the shaft,
Which has
An in-pipe imaging device, characterized in that: A reflector which has an opening at an end and is attached to a tube to be photographed whose inside is photographed by an in-tube photographing device from the outside of the opening end,
A mounting ring body that is fitted to the opening end of the imaging target tube and has an insertion hole at the center of its axis,
A shaft body extending from the insertion hole of the mounting ring body toward the back of the tube along the axis of the imaging target tube;
A reflector having a reflecting surface facing the open end and provided at a tip of the shaft body,
With
The reflection surface is arranged on the far side of the tube from the photographable area of the in-tube photographing device,
A reflector, characterized in that: A tube to be photographed having an opening at its end is illuminated with illumination light from the outside of the opening end toward the inside of the tube. An in-tube shooting method for shooting,
A reflector is provided on the inner side of the tube of the in-pipe photographing apparatus in the photographing target tube from the photographable area of the in-pipe photographing apparatus. Shoot,
An in-tube imaging method, characterized in that:

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