JPH064333Y2 - Fiberscope monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] This invention transmits an image of an object to be monitored from one end of an image fiber to the other end of the image fiber and projects the image on an image pickup surface of the video camera, and based on a video signal of the video camera. The present invention relates to a fiberscope monitoring device for displaying an image of a monitoring target on a video monitor. More specifically, when there are targets with different emission wavelengths and brightness within the monitoring range, the fiberscope monitoring is effective for monitoring them. Regarding the device.

[Prior Art] The image fiber developed by applying the manufacturing technology of the optical fiber for communication has excellent resolution, heat resistance and radiation resistance, and has low low transmission loss and long length. The monitoring device that combines a fiberscope using this image fiber and a video camera was placed in a high temperature or low temperature place where conventional video cameras cannot be used, or in a special environment such as a strong electromagnetic field atmosphere or a radiation atmosphere. It is used as a device to monitor the object to be observed from a distance.

Conventionally, as an example of this type of monitoring apparatus, a burner flame monitoring apparatus in a thermal power plant will be described with reference to FIG.

This monitoring device monitors the combustion state of the burner flame A of the burner 1. First, an image of the burner flame A is formed by the objective lens 3 on one end 2a of the image fiber 2 inserted in the furnace, It is transmitted from the other end 2b to the outside of the furnace through the image fiber 2. An image of the other end 2b of the image fiber 2 is recorded by a video camera 7 by an optical system including an eyepiece lens 4, a filter 5, a diaphragm mechanism 6 and the like.
Is projected on the image plane 7a. The video camera 7 has a flame A
Image is electrically converted into a video signal, and the video signal is reproduced by the video monitor 8 as an image of the flame A. In reality, the optical system between the image fiber 2 and the video camera 7 has a relay lens (not shown) in addition to the eyepiece 4.

In such a configuration, the diaphragm mechanism 6 is adjusted so that the object to be observed can be imaged in an optimum state and that the object to be observed can be selected and imaged. In the case of a boiler of a thermal power plant, when the light oil is used as a fuel, the flame A becomes orange with a high brightness (close to infrared), so the infrared cut filter 5 and the diaphragm mechanism 6 are used to reduce the light amount. . Also, LN
The flame A when G is used as fuel becomes blue with low brightness and high transparency (closer to ultraviolet), so the color temperature correction filter 5 is used to set the aperture mechanism 6 to open. Such adjustment is adjustment according to the optical characteristics of the object to be observed, and is particularly important for monitoring with a color image.

[Problems to be Solved by the Invention] By the way, when there are a plurality of objects having different emission wavelengths and luminances within the monitoring range, for example, when burning light oil with a flame due to LNG in a boiler furnace, it depends on each flame. It is necessary to adjust the diaphragm mechanism 6. But,
A diaphragm mechanism 6 adapted to each of a plurality of objects to be observed.
Was extremely difficult to adjust.

The present invention solves such a problem.

[Means for Solving Problems] A fiberscope monitoring device of the present invention transmits an image of a monitoring target from one end of an image fiber to the other end, projects the image on an image pickup surface of a video camera, and outputs a video signal of the video camera. Based on this, in a fiberscope monitoring device that displays the image of the monitoring target on a video monitor, a beam splitter that splits the image of the monitoring target that has entered from the image fiber into multiple beams, and a plurality of monitoring targets that are split by this beam splitter. A plurality of video cameras corresponding to each of the images and capturing these images, and transmitting each of the images to be monitored split by the beam splitter to the corresponding video camera, and having an optical filter and diaphragm mechanism. Transmission wavelength range of
A plurality of optical transmission systems that adjust the light amount to optimize the imaging conditions; and an effect amplifier that inputs each of the image signals of the plurality of video cameras, cuts out each image, and combines them into one image, It is characterized by comprising a video monitor for displaying an image synthesized by the effect amplifier.

[Operation] According to the present invention, therefore, the image transmitted by the image fiber is divided into a plurality of images, each image is made into an optimum image pickup state, and then the images are separately picked up, and these images are reproduced again. Even if there are targets having different emission wavelengths or luminances within the monitoring range, the optimum images are displayed as one screen.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

FIG. 1 and FIG. 2 are views for explaining the first embodiment of the present invention. In the case of this embodiment, the observed object is L
The flame A of the burner 11 using NG as a fuel and the flame B of light oil burned by the flame A are two, and these flames A and B are observed at the same time.

The images of the flames A and B are formed on the one end 13a of the image fiber 13 by the objective lens 12, and transmitted through the image fiber 13 to the outside of the furnace from the other end 13b. The image of the other end 13b of the image fiber 13 is
It enters a half mirror (beam splitter) 15 through an eyepiece lens 14 and is split into two by this half mirror 15. The branched one is projected onto the image forming surface 16a of the first video camera 16 by the first light transfer system L1, and the other one is connected to the second video camera 17 by the second light transfer system L2. It is projected on the image plane 17a. The first light transmission system L1 is composed of a first filter 18 and a diaphragm mechanism 19, and the second light transmission system L2 is composed of a second filter 20 and a diaphragm mechanism 21.

The first light transmission system L1 and the video camera 16 are for monitoring the flame A of the LNG. Therefore, the filter 18 of the first light transmission system L1 is a filter for color temperature correction so as to adapt to the flame A of LNG, that is, the blue flame of low transparency and high transparency, and the diaphragm mechanism 19 is Has been released. On the other hand, the second light transmission system L2 and the video camera 17 are for monitoring the flame B of light oil. Therefore, the filter 20 of the second optical transmission system L2
Is an infrared cut filter so as to adapt to the flame B of light oil, that is, an orange flame with high brightness, and the diaphragm mechanism 21 is set to restrict the amount of light.

As a result of the setting of the first and second light transmission systems L1 and L2 in this way, the first video camera 16 outputs the optimum video signal for the flame A of LNG, but the flame B of light oil. Will output a video signal that exceeds the light amount. On the other hand, the second video camera 17 outputs the optimum video signal for the flame B of light oil, but the LN
For the flame A of G, a video signal of insufficient light amount is output.

The video signals output from the first and second video cameras 16 and 17 are effect amplifiers (ME amplifiers; Mix and Mix).
Effect amp) 22 synthesized and then video monitor 2
It is displayed as one video at 3. Effect amplifier 2
Reference numeral 2 denotes an amplifier that varies the gain of an input image signal by a keying signal supplied from the outside, and can perform a wipe (screen combination) known as a video special effect. For example, when a keying signal that makes a circle "O" is added on the screen of the video monitor 23, two screens are switched at the boundary of the circle to form one screen. That is, the other one screen fits in a circle in one screen. Usually, the keying signal has a fixed pattern. In the case of this example, a keying signal generation circuit 24 is connected between the first video camera 16 and the effect amplifier 22, and a keying signal for screen synthesis is generated based on the video signal of the video camera 16. It is supposed to be generated.

Next, the processing of the video signal in the effect amplifier 22
It will be described with reference to the drawings.

FIG. 7A shows a video signal from the first video camera 16 (hereinafter referred to as “first video signal”), and FIG.
The video signal from the video camera 17 (hereinafter referred to as "second video signal"), FIG. 7C represents the video signal synthesized by the effect amplifier 22. In these figures, the voltage corresponding to the luminance is plotted on the ordinate and the time is plotted on the abscissa, Ec is the upper limit voltage, and T is the horizontal search period.
Here, the range of T1 corresponds to the image centered on the flame B of light oil, and the T2 range corresponds to the image centered on the flame A of LNG.

Since the first light transmission system L1 is adjusted as described above, the first video signal has a portion due to excess light. That is, there is a period Ts during which the signal voltage reaches the upper limit voltage Ec during the period T1 corresponding to the flame B of light oil. On the other hand, in the second video signal, since the second light transmission system L2 is adjusted as described above, a portion due to insufficient light amount occurs. That is, during the period T2 corresponding to the flame A of LNG, the luminance is low and the signal voltage for obtaining an appropriate image cannot be obtained.

The effect amplifier 22 inputs the first and first video signals as described above, and synthesizes the video signals based on the keying signal from the keying signal generation circuit 24. The keying signal generation circuit 24 sets the comparator voltage value Es for detecting the period Ts, and outputs the keying signal during the period when the first video signal is equal to or higher than the voltage Es. Based on this keying signal, the effect amplifier 22
Is a portion of the first video signal during the period Ts,
Replacing the period Ts portion of the second video signal,
The video signals of (c) are combined. As a result, as for the light amount excess portion in the image pickup screen of the first video camera 16, the screen of the second video camera 17 which picked up the portion with an appropriate light amount is replaced, and the video monitor 2
3 displays those combined screens.

The comparator voltage Es in the keying signal generation circuit 24 has a value (0 ≦ Es ≦) up to the upper limit voltage Ec.
Ec) can be set. For example, when the voltage Es' corresponding to the maximum brightness of the flame A of LNG is set,
LN in the screen imaged by the first video camera 16
The portion of the flame A of G having the maximum brightness or higher is displayed by replacing the portion with the screen imaged by the second video camera 17. Also, for color images,
Since the video signal is a combination of a luminance signal and two color difference signals, by incorporating a circuit for electrically generating a keying signal for discriminating a difference in hue as the keying signal generation circuit 24, it is possible to obtain a different color difference. A composite image can be displayed. As described above, the apparatus according to the present invention can automatically change the range of image synthesis according to the change of the observed image by the keying signal. Therefore, an optimum image can be obtained even when the object moves or its brightness changes. This cannot be realized with a filter having a density distribution.

Further, the number of images to be combined is not limited to two as in the above embodiment. For example, a half mirror 15 is added in accordance with an object having a different emission wavelength or brightness, an image transmitted by the image fiber 13 is branched into two or more, and each image is projected onto two or more corresponding video cameras. can do. Further, in such a case, the keying signal generation circuit 24 and the effect amplifier 22 may be configured to process two or more video signals.

FIG. 3 is an explanatory diagram when the monitoring device of the present invention is applied for monitoring arc welding.

In the figure, 25 is an electrode rod, which generates an arc C when a high voltage is applied between it and the processed material 26,
The groove portion of the processed material 26 is fusion-bonded. 27 is a weld bead. Weld beads 2 at the joint for good quality welding
The width of 7 must be constant, and the positional relationship between the electrode rod 25 and the work material 26, the voltage value, and the moving speed of the work material 26 must be controlled according to the shape of the welding bead 27. By the way, bright arc In contrast to C, the groove portion of the processed material 26 and the weld bead 27 are extremely dark. Therefore, the transmission characteristics of the first and second light transmission systems L1 and L2 are adjusted according to the former brightness, and the other transmission characteristics are adjusted according to the latter brightness, and the fiberscope objective section 28 is adjusted. An image of the welded portion is input to the image fiber 13 through the. Then, by synthesizing the video signals of the first and second video cameras 16 and 17, the part where the light amount of the arc C is over in one screen is replaced with the other screen. As a result, it is possible to observe the situation of each part where the difference in brightness is large at the same time and control the welding by the image, and at the same time, observe the state of the metal deposited on the electrode rod 25 during the work, and the welding device. It is convenient for maintenance and inspection.

By the way, when the conventional monitoring device is used, it is not possible to observe each part at the same time due to a large difference in brightness. That is, so that the tip of the electrode rod 25 can be observed,
That is, when the filter and the diaphragm mechanism are adjusted according to the brightness of the arc C, the groove portion of the processed material 26 and the welding bead 2
7 is too dark to observe, and conversely, when the shape of the welding bead 27 can be observed, that is, when the filter and the diaphragm mechanism are adjusted according to the brightness of the welding bead 27, the arc C is too bright and the electrode The shape of the rod 25 and the groove of the processed material 26 cannot be observed.

[Effects of the Invention] As described above, the fiberscope monitoring apparatus of the present invention provides a plurality of independent optical systems having different optical transfer characteristics for the image transmitted by the image fiber and the optimum imaging condition for each image. And then project them on multiple video cameras and then combine them into a single screen,
Since it is configured to display, even if there are targets with different emission wavelengths and brightness within the monitoring range, it is possible to obtain the optimum images by optimally setting the filters and diaphragms according to each. You can observe them as one screen.

Further, since the image of the object to be observed is transmitted by the image fiber, even if the number of branching by the beam splitter is increased and the number of video cameras is increased, the image can be unified in the same shape and the same size. The size of the objective part of the fiberscope does not increase.

If a fiberscope is already installed,
It can be configured using it.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of the first embodiment of the present invention, FIG. 2 is an explanatory diagram of the operation of the same embodiment, and FIG. 3 is an explanatory diagram of an object to be observed in the second embodiment of the present invention. is there. FIG. 4 is a schematic configuration diagram of a conventional example. 13 ... Image fiber, 15 ... Half mirror (beam splitter), 16, 17 ... Video camera, 22 ... Effect amplifier, 23 ... Video monitor, A, B ... Flame, L1, L2 ... Light Transmission system.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Cho Fukuda 1440 Rokuzaki, Sakura City, Chiba Fujikura Electric Co., Ltd. Sakura Factory (56) Reference JP 58-82952 (JP, A) JP 60-77743 (JP, A) Actually developed 60-28730 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A fiber for transmitting an image of an object to be monitored from one end of an image fiber to the other end of the image fiber and projecting the image on an image pickup surface of the video camera, and displaying the image of the object to be monitored on a video monitor based on a video signal of the video camera. In a scope monitoring device, a beam splitter that branches an image of a monitoring target that has entered from an image fiber into a plurality of images, and a plurality of images of the monitoring target that are branched by this beam splitter, respectively, and these images are captured. It transmits a plurality of video cameras and each of the images to be monitored split by the beam splitter to the corresponding video camera, and has an optical filter and a diaphragm mechanism.
A plurality of light transmission systems that adjust the light amount to optimize the imaging conditions; an effect amplifier that inputs each of the image signals of the plurality of video cameras, cuts out each image, and combines them into one image; A fiberscope monitoring apparatus comprising a video monitor for displaying an image synthesized by the effect amplifier.