JP2964976B2 - Fiberscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fiberscope, and more particularly, to a fiberscope for observing the inside of a pipe.

[0002]

2. Description of the Related Art Conventionally, inspections for the presence of defects such as cracks in pipes and the presence of foreign matter have been performed by, for example, a fiberscope using an optical fiber. That is, an optical fiber is inserted into a pipe, and an image inside the pipe transmitted by the optical fiber is observed via a monitor. However, since the inside of the pipe is observed in the straight traveling direction, it is very difficult to observe the radial position of the pipe. For example, it is not possible to observe a location immediately after the inner diameter of the pipe has rapidly expanded, unless an optical fiber is inserted from the opposite direction, and the field of view is limited. Therefore, in order to solve such inconvenience, Japanese Utility Model Laid-Open No. 62-763 has been proposed.
A fiberscope as described in Japanese Patent Publication No. 15 has been proposed. This fiberscope receives light from the inner wall of the nearest pipe through an optical system including a prism mirror and an objective lens provided on the distal end side of the optical fiber so that the state of the inner wall of the pipe can be observed. Is configured.

[0003] In addition, a fiber scope described in Japanese Patent Application Laid-Open No. 7-83641 has a plurality of optical fibers arranged in a ring shape to form a ring guide terminal, and
The other end is connected to the monitor side, an image of the inner wall of the pipe is made incident on the ring guide terminal via a conical mirror, transmitted through the optical fiber, and the image is observed on the monitor. Here, the light that has passed through the optical fiber is received by a sensor, converted into an electric signal, and temporarily stored in a memory as image information. At the same time, the optical fiber and the mirror are moved a predetermined distance in the pipe along the pipe axis direction using a stepping motor or the like. Thereafter, image information indicating the state of the inner wall of the pipe in a desired range is displayed on the monitor.

[0004]

However, both of the fiberscopes described in the above publications can reliably observe the state of the inner wall of the pipe, but cannot simultaneously observe the state of the inside of the pipe in the direction of the pipe axis. There is a disadvantage that it cannot be done. Further, the fiber scope described in JP-A-7-83641 has a problem that the inside of the pipe cannot be observed in real time in accordance with the operation of inserting the optical fiber. For this reason, for example, even if foreign matter is mixed in the piping, there is a possibility that the foreign matter may be overlooked.

The present invention has been made in view of the above circumstances, and provides a fiber scope which can simultaneously detect the state of the inside of the pipe in the axial direction and the radial direction to reliably detect an abnormality in the inside of the pipe. It is intended to provide.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 comprises a bundle of optical fibers, an objective lens arranged at one end of an image guide for transmitting an image, and A camera is arranged on the end side, and a first curved mirror is arranged in front of the objective lens, so that light arriving from the side can be incident on the objective lens and can be viewed from the side. According to the fiber scope described above, the curved mirror is a semi-transparent mirror, so that light coming from the front of the objective lens is also made incident on the objective lens so that it can be directly viewed. And

According to a second aspect of the present invention, there is provided the fiber scope according to the first aspect, comprising an optical fiber.
A light guide for illuminating a subject is also added, and a second curved mirror is arranged on an output end side of the light guide, so that a side object can be illuminated. I have.

According to a third aspect of the present invention, there is provided the fiber scope according to the second aspect, wherein the second curved mirror is also a semi-transparent mirror, so that an object in front of the objective lens can be illuminated. It is characterized by being.

According to a fourth aspect of the present invention, there is provided the fiber scope according to the first or second aspect, wherein the first curved mirror includes at least a part of light arriving from the front of the curved mirror. It is characterized in that it is arranged at a position where it can enter the objective lens.

[0010]

[0011]

According to the structure of the present invention, since the first curved mirror is disposed in front of the objective lens, light arriving from the side can be made incident on the objective lens and can be viewed from the side. Further, since the curved mirror is a semi-transmissive mirror, light coming from the front of the objective lens can also be made incident on the objective lens to allow direct viewing. That is, it is possible to simultaneously observe the state in the pipe axis direction and the radial direction inside the pipe. Therefore, the complexity and complexity of alternately switching between side observation and direct observation using the switching means can be avoided.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The description will be specifically made using an embodiment. FIG. 1 is a configuration diagram showing an overall configuration of a fiberscope according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view showing a state where the distal end of the fiberscope is inserted into a pipe. As shown in FIG. 1, a fiber scope 1 of this example is used, for example, for inspecting the state of the inside of a pipe 2, and a light source 11 for illuminating the inside of the pipe 2 and a light source 11 inserted into the inside of the pipe 2 for illumination. A light guide 12 for transmitting light, an image guide 13 inserted into the pipe 2 together with the light guide 12 to transmit an image of the inside of the pipe 2 received at the distal end surface, and an illumination guide received from the light guide 12. A ball mirror 14 that reflects light on the mirror surface 141 for illumination and strikes the inner wall 21 of the pipe 2 and reflects light received from the inner wall 21 of the pipe 2 toward the distal end surface of the image guide 13 on the observation mirror surface 142; The objective lens 15 disposed between the distal end surface of the image guide 13 and the observation mirror surface 142, the light guide 12 and the image guide 13 are bundled at the distal end portion, and the ball mirror 14 The observation mirror 142 is disposed at a predetermined distance from the distal end surface of the image guide 13, and the center of the observation mirror 142 is moved by a predetermined distance from the center axis of the image guide 13. Light guide 1 to hit
A holder 16 for holding the front end of the camera 2 and a camera 17 for receiving light transmitted through the image guide 13 from the front end and converting the light into an electric signal, using a CCD or the like; An image processing device 18 that creates an image signal based on the electric signal sent from the camera 17, and a monitor 19 that receives the image signal created by the image processing device 18 and displays an image indicating the state of the inside of the pipe 2. I have it.

The light guide 12 is made of, for example, an optical fiber for illumination having a diameter of about 1 mm, one end of which is disposed below the ball mirror 14 and the other end of which is the light source 1.
1 connected. The image guide 13 has a large number of optical fibers for observation bundled, for example, with a diameter of about 3 mm, and is connected to the camera 17 at the rear end side. Each optical fiber constituting the light guide 12 and the image guide 13 is a step index type optical fiber using quartz glass. Further, the ball mirror 14 has a sphere having a diameter slightly smaller than the diameter of the image guide 13, and a lower part on the inner side of the sphere is cut into a spherical shape. In both cases, silver or aluminum is vapor-deposited to form a mirror surface 141 for illumination and a mirror surface 142 for observation, respectively. In addition, a circle having the circumference of the spherical region forming the illumination mirror surface 141 as a circumference is inclined at an inclination angle of about 45 degrees with respect to the horizontal plane, including the pipe axis of the pipe 2.

The illumination mirror surface 141 and the observation mirror surface 1
42 are both semi-transparent mirrors, and the illumination fiber 1
A part of the illumination light emitted from 2 is reflected by the mirror surface 141 for illumination and reaches the observation mirror surface 142, and a part of this light passes through and illuminates the inner wall 21 of the pipe 2. Another part of the illumination light passes through the illumination mirror surface 141 and illuminates the front of the pipe 2. The center of the ball mirror 14 is
The light guide is arranged at a predetermined distance from the center axis of the image guide 13, and a part of the light arriving from the front passes between the ball mirror 14 and the inner wall 21 and another part. Are transmitted through the observation mirror surface 142 and enter the image guide 13. On the other hand, the light reflected by the inner wall 21 of the pipe 2 and reaching the observation mirror surface 142 is reflected by the observation mirror surface 142, and a part of the reflected light enters the image guide 13.

The image processing device 18 receives the electric signal sent from the camera 17 and generates an image signal by correcting the image distortion caused by the observation mirror 142 based on the electric signal. Here, a side-view image that looks at the wall surface 21 in the radial direction of the pipe 2 and a direct-view image that looks at the front (pipe axis direction) inside the pipe 2 are separated, and a corresponding side-view image signal and a direct view, respectively. An image signal is generated and sent to the monitor 19. The monitor 19 divides the side-view image and the direct-view image into corresponding side-view image regions 191 and 192 based on the side-view image signal and the direct-view image signal received from the image processing device 18, respectively. indicate.

Next, the operation of this example will be described. First, the light source 11 emits light for illumination. This illumination light travels through the light guide 12, and as shown in FIG.
The light is emitted from the end face of the illumination fiber 12 to illuminate the inside of the pipe 2. Here, a part of the emitted illumination light is reflected by the illumination mirror surface 141 of the ball mirror 14 and passes through the observation mirror surface 142 to illuminate the inner wall 21 of the pipe 2. Another part is transmitted through the mirror surface 141 for illumination, and
To illuminate the inside of the pipe 2 in front. The light reflected by the inner wall 21 and returned to the observation mirror surface 142 is reflected by the observation mirror surface 142, and a part of the light is reflected by the observation mirror surface 142.
The light enters the image guide 13.

Here, for example, as shown in the figure, even when the pipe 2 forms a concave portion 22, is suddenly thickened, or is branched in a T-shape or cross, Illumination light is applied to the inner wall 21, and a part of the light reflected here reaches the observation mirror surface 142 and further enters the image guide 13. In addition, a foreign substance mixed in the pipe 2 and a part of the light reflected on the front inner wall 21 pass through the concave portion 22 side of the ball mirror 14 and
The other part passes through the observation mirror surface 142 and enters the image guide 13.

The light incident on the image guide 13 is transmitted through the image guide 13, received by the camera 17, and converted into an electric signal. The image processing device 18 receives the electric signal sent from the camera 17, corrects an image distortion, generates a side-view image signal and a direct-view image signal, and sends them to the monitor 19. The monitor 19 displays the side-view image area 1 based on the side-view image signal and the direct-view image signal.
91 is a side-view image, a direct-view image area 192 is a direct-view image,
Display each. Here, in the side view image area 191, for example, a precise image of the state of the concave portion 22 of the pipe 2 is displayed, and the inspector observes this image and inspects for cracks or the like. In the direct-view image area 192,
An image in the pipe axis direction inside the pipe 2 is displayed, and the inspector
The inside of the pipe 2 is inspected for a state in front and for the presence of foreign matter. In this way, while inserting the distal end of the fiber scope 1 into the inside of the pipe 2, the inspector observes a screen displayed in real time and inspects the inside of the pipe 2 thoroughly.

According to the above configuration, a part of the illumination light emitted from the front end surface of the light guide 12 is a mirror surface 14 for illumination.
1 illuminates the inner wall 21 of the pipe 2 through the observation mirror surface 142 and transmits another part through the illumination mirror surface 141 to illuminate the inside of the pipe 2 in front. A part of the light arriving from the front of the pipe 2 is arranged on the tip end side of the image guide 13 so as to enter the image guide 13, and the observation mirror surface 142 receives the light received from the inner wall 21 of the pipe 2. Is reflected toward the image guide 11, so that the state of the pipe 2 in the radial direction (side view screen) and the state of the pipe 2 in the pipe axis direction (direct view screen) can be observed. Therefore, it is possible to reliably detect a defect of the inner wall 21 of the pipe 2 or the intrusion of a foreign substance into the inside. Also, at the tip of the image guide 13 and the light guide 12,
Since the substantially spherical ball mirror 14 is attached,
The image guide 13 and the like can be smoothly inserted into the pipe 2.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like that do not depart from the gist of the present invention. Is also included in the present invention. For example, in the above-described embodiment, the case where the observation mirror surface 142 and the illumination mirror surface 141 have spherical shapes has been described. However, the present invention is not limited to spherical surfaces, and may be, for example, elliptical surfaces or parabolic surfaces. good.
Further, the present invention is not limited to the convex mirror, but may be a concave mirror. Also,
The case where the illumination mirror surface 141 is a semi-transparent mirror has been described. However, as shown in FIG. 3, the illumination mirror surface 141 a is arranged so as to be further concealed with respect to the pipe axis direction of the pipe 2, as shown in FIG. The illumination light emitted from the center side (upper part) of the ball mirror 14a on the distal end surface of the guide 12 toward the illumination mirror surface 141a passes above the illumination mirror surface 141a and reaches forward in the pipe 2. Is also good.

Further, in the above-described embodiment, the case where the illumination mirror surface 141 and the observation mirror surface 142 are formed on the ball mirror 14 has been described. However, as shown in FIG. The base body 3 may be provided integrally, and the illumination mirror surface 31 and the observation mirror surface 31 may be formed at predetermined positions of the optical base 3. Further, as shown in FIG. 5, the light guide 12 may be eliminated, and the light of a separately prepared light source may be directly applied to the inside of the pipe 2 using a ball mirror 14b having only the observation mirror surface 142b. good. As shown in FIG. 6, the light guide 12 and the ball mirror 14 are eliminated, the prism 3a is integrally provided at the tip of the image guide 13, and the observation mirror surface 32a is formed at a predetermined position of the prism 3a. You may do it. Each optical fiber used for the light guide 12 and the image guide 13 is not limited to the step index type, but may be a graded index type. Further, the material of the optical fiber is not limited to quartz glass. In the monitor 19, the screen may not be divided in the tube axis direction and the radial direction, and may be displayed on the same screen.

[0022]

As described above, according to the structure of the present invention, since the first curved mirror is disposed in front of the objective lens, light coming from the side is incident on the objective lens. You can see from the side. Further, since the curved mirror is a semi-transmissive mirror, light coming from the front of the objective lens can also be made incident on the objective lens to allow direct viewing. That is, it is possible to simultaneously observe the state in the pipe axis direction and the radial direction inside the pipe. Therefore, the complexity and complexity of alternately switching between side observation and direct observation using the switching means can be avoided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a schematic configuration of a fiberscope according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state where the fiber scope is inserted into a pipe.

FIG. 3 is a cross-sectional view showing a state in which a distal end of a fiberscope which is a modification of the embodiment of the present invention is inserted into a pipe.

FIG. 4 is a cross-sectional view showing a state in which a distal end portion of a fiber scope as another modified example of the embodiment of the present invention is inserted into a pipe.

FIG. 5 is a cross-sectional view showing a state where a distal end portion of a fiberscope which is still another modification of the embodiment of the present invention is inserted into a pipe.

FIG. 6 is a cross-sectional view showing a state in which a distal end of a fiberscope which is still another modification of the embodiment of the present invention is inserted into a pipe.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fiberscope 12 Light guide 13 Image guide 141, 141a Illumination mirror surface (2nd curved mirror) 142 Observation mirror surface (1st curved mirror) 15 Objective lens 17 Camera 18 Image processing device (Image processing means) 2 Piping ( subject)

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02B 23/26

Claims (4)

(57) [Claims] An image guide for transmitting an image is provided with an objective lens at one end and a camera at the other end, and a first lens is provided in front of the objective lens. By arranging the curved mirror of the above, the light coming from the side is incident on the objective lens, a fiber scope configured to be viewed from the side, the curved mirror is a semi-transparent mirror A fiberscope characterized in that light coming from the front of the objective lens is also made incident on the objective lens so that the light can be viewed directly. 2. An optical fiber, a light guide for illuminating a subject is also added, and a second curved mirror is arranged on an output end side of the light guide, so that a side projecting object is formed. The fiberscope according to claim 1, wherein the fiberscope is configured to be illuminated. 3. The fiberscope according to claim 2, wherein the second curved mirror is also a semi-transmissive mirror so that a subject in front of the objective lens can be illuminated. 4. The apparatus according to claim 1, wherein the first curved mirror is arranged at a position where at least a part of the light arriving from the front of the curved mirror can enter the objective lens. Or the fiberscope according to 2.