JP2001259883A - Observing device, monitoring device, welding equipment, and method of welding work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of welding work using a solid-state image pickup device equipped with a solid-state image pickup element which has a broad dynamic range and outputs an electric signal logarithmically transformed with respect to an incident light. SOLUTION: An area sensor 22 outputs an electric signal logarithmically transformed with respect to an incident light when a welding zone image is picked up by the area sensor 22 through an objective lens 21. A signal processing of the electric signal outputted from the area sensor 22 is carried out by a control unit 25 where an electric signal of a high intensity output representing a high luminance part in the vicinity of an arc light generation part is suppressed into a low luminance. An image is reproduced on a liquid crystal display part 23 on the basis of the processed electric signal and the reproduced image is observed by a worker through an eyepiece.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an observation device, a monitoring device, a welding device, and a welding method using an imaging device for imaging a welded portion.

[0002]

2. Description of the Related Art For example, when a metal is welded by arc welding, strong light is generated by a molten metal or arc light. If this light enters the eyes of the worker directly, the eyes are hurt. Therefore, the worker usually wears light-shielding glasses to perform the welding operation. However, these shading glasses only weaken the intensity of light passing through the lens at a constant rate. In addition, the arc light generated at the welded portion and the strong light generated from the molten metal are weakened, but the dark portions around the periphery without strong light are hardly seen. Therefore, infrared cameras and CCDs (Charge Coupled
vice) A method of monitoring and welding a welded portion using a camera or the like has been proposed.

[0003]

However, although the infrared camera can obtain the shape of the molten pool, it cannot recognize the situation in the groove which is the part to be actually welded. In addition, a CCD camera or the like is provided with a solid-state imaging device that outputs an electric signal that is linearly converted with respect to the amount of incident light. However, since the dynamic range of this solid-state imaging device is narrow and limited, monitoring is possible. It becomes impossible to obtain an image.

[0004] In view of the above problems, the present invention provides an observation method capable of simultaneously observing a molten metal or its surroundings in a welded portion or the like that generates intense light and the surroundings of a low luminance portion. It is an object to provide a device and a monitoring device. Further, the present invention also provides a welding apparatus and a welding operation capable of performing a welding operation by accurately recognizing a molten metal or its surroundings in a welding part or the like that generates intense light, and a surrounding low-luminance part. The aim is to provide a method.

[0005]

According to a first aspect of the present invention, there is provided an observation apparatus which captures an image of a molten metal and its periphery, and outputs an electric signal obtained by logarithmically converting incident light. And a display unit that reproduces an image based on an electric signal output from the imaging device.

According to such an observation device, the dynamic range is widened because the imaging device outputs an electric signal logarithmically converted with respect to the incident light. Therefore, for example, when imaging the periphery of the welded part when performing arc welding,
It is possible to capture an image with a wide luminance range from the high luminance portion near the molten metal to the peripheral portion of the welded portion with high definition. Therefore, when an image is reproduced on the display unit based on an electric signal output from such an imaging device,
A high-definition image in which the periphery of the molten metal having high luminance and the dark portion having low luminance are clearly displayed is displayed.

According to a second aspect of the present invention, there is provided a monitoring device which captures an image of a welded portion and its periphery, and outputs an electrical signal obtained by logarithmically converting incident light, and a signal output from the solid-state image capture device. And a display unit for reproducing an image based on the electric signal.

According to such a monitoring device, the solid-state imaging device outputs an electric signal obtained by logarithmically converting incident light, so that the dynamic range is widened. Therefore,
For example, when an image of the periphery of the welded part is taken at the time of arc welding, it is possible to take an image with a wide luminance range from the high luminance part near the arc light generating part to the peripheral part of the welded part with high definition. Therefore, when an image is reproduced on the display unit based on an electric signal output from such a solid-state imaging device, a high-definition arc light having a high luminance and a high-definition dark part having a low luminance are clearly displayed. The image is displayed.

In such a monitoring device, for example, arc welding is performed by performing signal processing on an electric signal output from the solid-state imaging device and reducing an electric signal having a high luminance output higher than a predetermined luminance. At this time, a high-luminance portion in the vicinity of the arc light generating portion is converted into an electric signal with low luminance, and an image is reproduced on the display unit based on the electric signal on which such signal processing is performed. A large amount of light can be prevented from entering the eyes of the operator observing, and safety can be ensured.

According to a third aspect of the present invention, an optical system for condensing light from a subject and light condensed from the optical system are incident and logarithmically converted with respect to the incident light. A solid-state imaging device that performs an imaging operation by outputting an electric signal and a liquid crystal display unit that reproduces an image based on the electric signal output from the solid-state imaging device are provided.

In such a monitoring apparatus, for example, when performing a welding operation such as arc welding, the solid-state image pickup device picks up an image of a periphery of a welded portion through an optical system. Then, based on the electric signal logarithmically converted by the solid-state imaging device that has taken an image of the periphery of the welded portion, it is observed by an operator via the eyepiece lens. Further, as described in claim 4, a mounting member for mounting on the eye of the observer may be provided.

A welding apparatus according to a fifth aspect of the present invention provides a welding torch inserted into a portion to be welded for performing welding, a moving mechanism for moving the welding torch to a welding portion,
An imaging device that images a welding portion and outputs an electrical signal that is logarithmically converted to incident light, monitors the welding portion with the imaging device, and moves the welding torch with a moving mechanism to perform welding. And

According to such a monitoring device, the dynamic range is widened because the imaging device outputs an electric signal obtained by logarithmically converting the incident light. Therefore, for example, when imaging around the welded part when performing arc welding,
It is possible to take a high-definition image of an image having a wide luminance range from the high luminance portion near the arc light generating portion to the periphery of the welding portion.

In such a welding apparatus, the state of the welded portion can be detected by providing a detection circuit for detecting the position of the welding line or the molten pool from the output of the imaging device. The drive of the welding torch and the moving mechanism can be controlled in accordance with the detected state. Further, in such a welding apparatus, stable welding can be performed by changing welding conditions according to the detection result of the detection circuit.

[0015] In such a welding apparatus, by performing edge detection from the image provided by the image pickup apparatus, a joint between the workpieces to be welded can be detected as a welding line. In addition, by detecting the edge of the weld pool by performing edge detection from an image given by the imaging device, the amount of wire fed from the welding torch can be changed according to the size of the weld pool, thereby improving the weld pool. Welding can be performed. Further, by detecting the center of the weld pool from the detected contour of the weld pool, the moving mechanism can be controlled such that the center of the weld pool is present on the welding line. Further, for example, when performing arc welding, by detecting an electric signal that becomes a high-luminance output, by detecting the discharge state of the arc light,
By changing the arc voltage or the like depending on the discharge state of the arc light and keeping the length of the arc light constant, it is possible to perform good welding.

A welding operation method according to an eighth aspect of the present invention is characterized in that a welding portion is monitored by using the monitoring device according to any one of the second to fourth aspects.

A welding method according to a ninth aspect is characterized in that the welding operation is performed by the welding device according to any one of the fifth to seventh aspects.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS <Around a Welded Part> The situation around a welded part will be described with reference to FIG. 1 taking an example of welding a metal material by arc welding. FIG. 1 is a diagram showing a situation around a welded portion when two works are welded.

As shown in FIG. 1, when welding a work 1 and a work 2 each made of a metal material, in the case of arc welding, the torch 3 is moved along a moving direction A, and a welding line serving as a joining portion is formed. 4. Insert wire 5 into wire 5
And welding is performed by generating an arc between the workpiece and the joint of the workpiece. In the portion where the wire 5 is inserted, a molten pool 6 in which the wire 5 is melted is generated, and arc light is generated, and strong light is generated in the welded portion and its vicinity. And
When an arc is generated at a portion where the wire 5 is inserted and arc welding is performed, a bead 7 is formed at a welding end portion. When arc welding is performed in this manner, the wire 5
Is inserted and the area where the molten pool 6 occurs and its surroundings are
A very dazzling state is caused by the strong arc light and the molten pool 6.

<Solid-State Imaging Device> A solid-state imaging device used in the present invention will be described with reference to the drawings. FIG.
1 is a circuit block diagram illustrating a configuration of a solid-state imaging device (hereinafter, referred to as an “area sensor”). FIG. 3 is a circuit diagram showing a part of the area sensor of FIG. FIG. 4 is similar to FIG.
FIG. 3 is a circuit diagram showing a configuration of a pixel in the area sensor of FIG.

In FIG. 2, G11 to Gmn indicate pixels arranged in a matrix (matrix arrangement). Reference numeral 11 denotes a vertical scanning circuit, and rows (lines) 13-1, 13-2,
.., 13-n are sequentially scanned. Reference numeral 12 denotes a horizontal scanning circuit which outputs output signal lines 15-1, 15-2,
.., The photoelectric conversion signals derived in 15-m are sequentially read in the horizontal direction for each pixel. 14 is a power supply line.
For each pixel, the lines 13-1, 13-2,.
13-n and output signal lines 15-1, 15-2,.
−m, not only the power supply line 14 but also other lines (for example, a clock line and a bias supply line) are connected, but these are omitted in FIG.

The output signal lines 15-1, 15-2,...
Every 15-m, an N-channel MOS transistor Q1,
Q2 is provided for each pair as shown. Taking the output signal line 15-1 as an example, the gate of the MOS transistor Q1 is connected to the DC voltage line 16, the drain is connected to the output signal line 15-1, and the source is the DC voltage VP.
It is connected to line 17 of S ′. On the other hand, the drain of the MOS transistor Q2 is connected to the output signal line 15-1, the source is connected to the final signal line 18, and the gate is connected to the horizontal scanning circuit 12.

As will be described later, the pixels G11 to Gmn have
An N-channel MOS transistor T2 for outputting a signal based on the photocharge generated in those pixels is provided. The connection relationship between the MOS transistor T2 and the MOS transistor Q1 is as shown in FIG. here,
The relationship between the DC voltage VPS 'connected to the source of the MOS transistor Q1 and the DC voltage VPD' connected to the drain of the MOS transistor T2 is VPD '>VPS',
The DC voltage VPS 'is, for example, a ground voltage (ground).
In this circuit configuration, a signal is input to the gate of the upper MOS transistor T2, and the DC voltage DC is constantly applied to the gate of the lower MOS transistor Q1. Therefore, the lower MOS transistor Q1 is equivalent to a resistor or a constant current source, and the circuit in FIG. 3A is a source follower type amplifier circuit. In this case, what is amplified and output from the MOS transistor T2 may be a current.

The MOS transistor Q2 is connected to the horizontal scanning circuit 1
2 and operates as a switch element.
As described later, an N-channel MOS transistor T3 for switching is also provided in the pixel of FIG. When this MOS transistor T3 is also included, FIG.
The circuit of FIG. 3A is exactly as shown in FIG. That is, the MOS transistor T3 is connected to the MOS transistor Q1.
And the MOS transistor T2. Here, the MOS transistor T3 is for selecting a row, and the transistor Q2 is for selecting a column.

The configuration of the pixels G11 to Gmn in the area sensor having such a configuration will be described below with reference to FIG. In FIG. 4, a pn photodiode PD forms a photosensitive section (photoelectric conversion section). The anode of the photodiode PD is connected to the drain and gate of the MOS transistor T1 and the gate of the MOS transistor T2. The source of the MOS transistor T2 is connected to the drain of the row selection MOS transistor T3. The source of the MOS transistor T3 is the output signal line 15
(This output signal line 15 corresponds to 15-1, 15-2,.
.., corresponding to 15-m). Note that M
Each of the OS transistors T1 to T3 is an N-channel MOS transistor and has a back gate grounded.

The DC voltage VPD is applied to the cathode of the photodiode PD and the drain of the MOS transistor T2. On the other hand, the DC voltage VPS is applied to the source of the MOS transistor T1, and the MOS transistor T1 is biased to operate in the sub-threshold region. Also, the MOS transistor T3
The signal φV is input to the gates of.

In the pixel having such a configuration, when light is incident on the photodiode PD, a photocurrent is generated, and M
Due to the sub-threshold characteristic of the OS transistor, M
A voltage having a value obtained by converting the photocurrent into a natural logarithm is generated at the gates of the OS transistors T1 and T2. By applying the pulse signal φV to the MOS transistor T3, the MOS transistor T2 outputs a source current according to the gate voltage to the signal line 15 via the MOS transistor T3 as an output current.

At this time, since the MOS transistor T2 operates as a source follower type MOS transistor, an output signal appears on the signal line 15 as a voltage signal.
Thereafter, the signal φV is changed to low level to turn off the MOS transistor T3. As described above, since the output signal output via the MOS transistors T2 and T3 has a value proportional to the gate voltage of the MOS transistor T2,
The amount of light incident on the photodiode PD is a signal obtained by natural logarithmic conversion.

The area sensor having the configuration as shown in FIG. 2 which outputs the logarithmically converted output signal with respect to the incident light amount has a wide dynamic range. No halation or blooming occurs in the reproduced image. Thus, the area sensor captures an image of a portion where arc light is generated, and the operator views the reproduced image to observe the molten pool 6 in FIG. 1 and its surroundings. Further, since it is possible to sufficiently image the state around the molten pool 6 in FIG. 1, by analyzing the image information, the torch 3 (FIG. 1), the inserted wire 5 (FIG. 1), and the welding line 4 can be measured.

Note that the configuration of the area sensor is not limited to that shown in FIG. 2, but may have a hold circuit for temporarily sampling and holding the output from the pixel. Also, the configuration of the pixel is not limited to the circuit configuration of FIG. 4 and may be any pixel that can perform a logarithmic conversion operation. For example, a pixel having a circuit configuration including an integration circuit or an amplification circuit may be used, or a circuit configuration that can detect sensitivity variation of each pixel due to a threshold characteristic of a MOS transistor provided therein may be used. I do not care.

<First Embodiment> A first embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a description will be given of a welding operation method performed by an operator observing a welding portion through a head-mounted monitoring device. FIG. 5 is a perspective view illustrating a configuration of the head-mounted monitoring device according to the present embodiment. FIG. 6 is a block diagram showing an internal configuration of the head-mounted monitoring device shown in FIG.

The head-mounted monitoring device 20 shown in FIG.
Is an object lens 21, an area sensor 22 that outputs an electric signal obtained by performing logarithmic conversion on light incident through the object lens 21 as described above, and a liquid crystal display that reproduces an image captured by the area sensor 22. Unit 23 and liquid crystal display unit 2
3, an eyepiece lens 24 provided on the image display side, a control unit 25 for performing signal processing on an electric signal output from the area sensor 22 and controlling the liquid crystal display unit 23 to reproduce an image based on the electric signal. , Are provided. In addition, the head-mounted monitoring device 20
As shown in FIG. 5, the eyepiece is shaped like a spectacle, and the eyepiece lens 24 is held in such a manner that the eyepiece lens 24 is brought into contact with the eye of the worker when the handle is put on the ear of the worker. The handle portion corresponds to the “mounting member” in the claims.

In the head-mounted monitoring device 20, an object is imaged by an area sensor 22 via an objective lens 21, and an electric signal logarithmically converted by the area sensor 22 with respect to the amount of incident light is transmitted to a control unit 25. Is output to In the control unit 25, an electric signal output from the area sensor 22 is processed by an image processing device 36 described later. The control unit 25 controls the liquid crystal display unit 23 based on the processed signal, and the image captured by the area sensor 22 is reproduced. Then, the operator can see the image displayed on the liquid crystal display unit 23 through the eyepiece lens 24.

The internal configuration of the control unit 25 will be described. As shown in FIG. 6, a CPU (Central Processing Unit) that controls each block via a bus line 37.
nit) 31, ROM (Read Only Memory) 32 storing software for performing control operations such as signal processing in the control unit 25, and data for performing signal processing in the image processing device 36 and the like are temporarily stored. RAM (Random Access Me)
mory) 33, a sensor controller 34 for controlling the area sensor 22, and a driving circuit 3 for controlling the liquid crystal display unit 23.
5, an image processing device 36 for performing signal processing on an electric signal transmitted from the area sensor 22, and a bus line 37.

The control unit 2 having such a configuration
When the operator is directed to the welded part to observe the welded part, the electric signal captured by the area sensor 22 is output to the sensor controller 34 in the head-mounted type monitoring device 20 provided with 5. Sensor controller 34
Is supplied to the image processing device 36 via the bus line 37.

Further, the electric signal from the area sensor 22 that has been subjected to the signal processing in the image processing device 36 is given to the drive circuit 35 via the bus line 37. In the driving circuit 35, an image is reproduced on the liquid crystal display unit 23 in accordance with an electric signal given from the image processing device 36.
The liquid crystal display unit 23 is controlled. Also, the sensor controller 3
Reference numeral 4 controls the timing of imaging each pixel of the area sensor 22, thereby controlling the exposure amount of light incident on each pixel. Further, the electric signal output from the area sensor 22 is converted into a digital signal by the sensor controller 34.

As described above, since the area sensor 22 outputs an electric signal logarithmically converted with respect to the amount of incident light, the image reproduced on the liquid crystal display unit 23 is an image in which the luminance near the arc light generating unit is suppressed. Therefore, a large amount of light does not accidentally reach the eyes of the operator. In addition, since the image is reproduced in a form close to the part other than the high-luminance part near the arc light generating part, the periphery of the welded part does not become difficult to be seen unlike the conventional light-shielding glasses.
Therefore, the operator can accurately observe the welded portion.

In the head-mounted monitoring device used in the welding operation method of the present embodiment, when an operator observes a welded portion, an electric signal is processed by an image processing device so that the operator can easily observe the welded portion. A manual switch for the operator to change the degree of the luminance to be changed may be provided. Further, by providing the image processing apparatus with an image enlargement / reduction function, the operator can observe a finer portion.

<Second Embodiment> A second embodiment of the present invention will be described with reference to the drawings. In the present embodiment, a description will be given of a welding device provided with a solid-state imaging device for observing a welded portion, and a welding operation method using the device. FIG. 7 is an external perspective view of the welding device of the present embodiment. FIG. 8 is a block diagram showing an internal configuration of the welding device shown in FIG.

The welding apparatus 40 shown in FIG. 7 includes a base 41, an arm 42 installed on the base 41, a sensor camera 43 provided at the tip of the arm 42 so as to image the welded portion, An arc welding torch 44 provided at the tip of the arm portion 42 and for inserting a wire into a welding line for performing arc welding. Also, the arm portion 42
By rotating the joints a, b, and c, the arc welding torch 44 can be moved to a target welding portion or can be moved along a welding line.

As shown in FIG. 8, the welding device 40 is provided with a control unit 50 for controlling the driving of the arm unit 42, the sensor camera 43, and the arc welding torch 44. The control unit 50 includes a CPU 51 that controls each block via a bus line 58, and a ROM that stores software and the like for performing control operations such as signal processing in the control unit 50.
52 and a RAM for performing an operation such as temporarily storing data for signal processing in the image processing device 54 and the like.
53, an image processing device 54 for processing an output signal from the sensor camera 43, an arm driving mechanism 55 for driving and controlling the arm 42, a welding torch control unit 56 for controlling the arc welding torch 44, and an external A communication device 57 for receiving an instruction signal from the controller 62;
And

The sensor camera 43 includes an objective lens 59.
And an area sensor 60 that outputs an electrical signal obtained by logarithmically converting incident light as described above, and a sensor controller 61 that controls the area sensor 60. Further, a monitor 63 is connected to the controller 62, and data processed by the image processing device 54 based on the electric signal output from the area sensor 60 is given via the communication device 57, and the data is Is reproduced on the monitor 63. When reproduced on the monitor 63 in this way, the operator observes the position of the arc welding torch 44, and when the operator moves the arc welding torch 44 to a target position, the instruction data is transmitted from the controller 62 to the communication device 57. And the drive of the arm unit 42 is controlled.

The operation of the welding device 40 having such a configuration will be described. The arm section 42 is driven and controlled by an arm drive mechanism 55 so that the arc welding torch 44 moves along the welding line. The welded portion is imaged by the sensor camera 43, and the electrical signal logarithmically converted by the area sensor 60 is converted into a digital signal by the sensor controller 61 and provided to the control unit 50.

As described above, the welding portion is imaged by the sensor camera 43, and the electric signal serving as the image data is transmitted to the control unit 5.
When given to 0, the image processing device 54 performs image recognition around the welded portion based on this electric signal. That is, the arc light is identified from the luminance represented by the electric signal output from each pixel of the area sensor 60, and the discharge state of the arc light is recognized. Further, by filtering an image obtained from the electric signal output from the area sensor 60, the edge of the joint between the works to be a welding line and the contour of the molten pool are detected.

An arc current applied to the wire of the arc welding torch 44 is controlled by the arc welding torch control unit 56 so that the arc light detected by the image processing device 54 keeps the length of the arc light constant. . Similarly, by detecting the relative relationship between the detected welding line and the arc light, an arm driving mechanism is provided so that the arc welding torch 44 does not move too close to the welding line or, conversely, does not move too far. 55 controls the arm 42 to rotate the joints a, b, and c of the arm 42.

Further, by recognizing the contour of the weld pool, the size of the weld pool generated at the welded portion is measured.
The arc welding torch control unit 56 controls the amount of wire fed from the arc welding torch 44 according to the size of the weld pool measured in this manner. That is, when the size of the molten pool is large, the amount of wire feeding is reduced, and when the size of the molten pool is small, the amount of wire feeding is increased. Thus, the joints a, b, and c of the arm 42 and the arc welding torch 44 are controlled by the arm drive mechanism 55 and the arc welding torch control unit 56 so that the arc welding can be performed normally.

Further, the image processing device 54 compares the welding line detected from the previously captured image with the welding line detected from the currently captured image. When matched in this way, the center of the weld pool is recognized from the contour of the weld pool detected from the currently captured image, and the center of the weld pool is placed on the welding line detected from the previously captured image. It is determined whether there is.

That is, it is assumed that an image as shown in FIG. 9A has been captured before and an image as shown in FIG. 9B has been captured at present. In FIG. 9, 9
1 is a welding line, 92 and 93 are weld pools, 94
Represents a bead. Note that point B represents the center of the molten pool 93 at the time when the imaging in FIG. 9B is performed. FIG.
FIG. 9A also shows point B in order to explain the correspondence with FIG. 9B. By recognizing the current imaging position based on the amount of movement of the arc welding torch 44, the coordinates of the image in FIG. 9A and the image in FIG. 9B are collated. Then, the welding line existing below the welding pool 93 in FIG. 9B can be recognized as shown in FIG. 9C. In this way, it is determined whether or not point B, which is the center of the weld pool 93, is on the welding line 91. If not, the arm unit 42 is driven by the arm unit driving mechanism 55. Controlled.

As described above, the control section 50 controls the arm section 42 and the arc welding torch 44 on the basis of the electric signal serving as image data obtained from the sensor camera 43, so that good welding along the welding line can be performed. It can be performed. Further, since the welding line can be recognized and the center of the weld pool can be recognized, good welding can be performed even in a complicated shape welding line.

The welding device 40 can perform wireless or wired communication with the controller 62 from the communication device 57. At this time, an electric signal given from the sensor camera 43 is transmitted as image data. When such image data is received by the controller 62, first, signal processing is performed on a portion having a high luminance near the arc light generating portion so as to reduce the luminance. Next, an image is reproduced on the monitor 63 based on the image data on which the signal processing has been performed as described above.

Then, the operator grasps the discharge state of the arc light and the state of the welding portion from the image displayed on the monitor 63, and operates the controller 62 in accordance with each state to drive the welding device 40. . At this time, a command signal representing an operator's operation command is transmitted from the controller 62 to the communication device 57. When the communication device 57 receives this command signal, the arm drive mechanism 55 and the arc welding torch control unit 56 control the drive of the arm unit 42 and the arc welding torch 44. The signal processing for reducing the high-luminance image data to low luminance may be performed by the image processing device 54.

By providing the communication device and the controller in this manner, a more accurate and favorable welding operation can be performed by the operator, and the high-luminance portion near the arc light generating portion is reproduced on the monitor 63 with low luminance. In addition, it is possible to prevent a large amount of light from entering the operator's eyes by mistake.

Although the above description has been made by taking arc welding as an example, the invention is not limited to this, and other welding such as gas welding, thermite welding, electroslag welding, electron beam welding, and laser beam welding may be used.

Although the above is the case of arc welding, the welding conditions may be changed by observing the welded portion in other welding as well. For example, in the case of gas welding,
The welding conditions may be changed by changing the gas flow rate or the like, or changing the components of the gas.

Although the present invention has been described by taking welding as an example, the present invention is not limited to welding, but can be applied to general observation of molten metal that generates intense light. The present invention is also applicable to a metal observation device and a monitoring device. Also in this case, the observation result may be fed back to the metal melting condition to change the metal melting condition.

[0056]

According to the observation apparatus of the present invention, since an image pickup apparatus which outputs an electric signal obtained by logarithmically converting incident light is used, an image having a wide luminance range can be taken with high definition. Thus, the molten metal and the high-luminance portion near the molten metal and the surrounding dark portion can be accurately imaged.
Moreover, a large amount of light does not enter the eyes of the observer, and the safety can be ensured. According to the monitoring device of the present invention,
In addition to the above effects, the situation of the high-brightness welded portion and the surroundings of the low-brightness welded portion can be simultaneously accurately grasped, which greatly contributes to facilitation and accuracy of the welding operation. Further, according to the welding apparatus and the welding operation method of the present invention, a welding line and a welding portion to be actually welded are accurately detected, so that good and accurate welding can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view around a welded portion.

FIG. 2 is a block circuit diagram showing a configuration of an area sensor.

FIG. 3 is a circuit diagram showing a part of the area sensor of FIG. 2;

FIG. 4 is a circuit diagram showing a configuration of a pixel provided in the area sensor of FIG. 2;

FIG. 5 is a perspective view showing a configuration of a head-mounted monitoring device.

FIG. 6 is a block diagram showing an internal configuration of the head-mounted monitoring device of FIG. 5;

FIG. 7 is an external perspective view of the welding device.

FIG. 8 is a block diagram showing the internal configuration of the welding device of FIG. 7;

FIG. 9 is a diagram showing an image when a welded portion is imaged.

[Explanation of symbols]

 Reference Signs List 1, 2 Work 3 Torch 4 Welding line 5 Wire 6 Weld pool 7 Bead 20 Head mounted monitoring device 21 Objective lens 22 Area sensor 23 Liquid crystal display unit 24 Eyepiece lens 25 Control unit 40 Welding device 41 Base 42 Arm unit 43 Sensor Camera 44 arc welding torch

Claims (9)

[Claims] 1. An image pickup apparatus for picking up an image of a molten metal and its surroundings and outputting an electric signal obtained by logarithmically converting incident light, and a display for reproducing an image based on the electric signal output from the image pickup apparatus. An observation device comprising: 2. A solid-state imaging device that images a welded portion and its periphery and outputs an electric signal obtained by logarithmically converting incident light, and reproduces an image based on the electric signal output from the solid-state imaging device. A monitoring device, comprising: 3. An optical system for condensing light from a subject, and light condensed from the optical system is incident thereon, and an electric signal obtained by logarithmically converting the incident light is output to perform an imaging operation. A monitoring device, comprising: a solid-state imaging device that performs the operation; and a liquid crystal display unit that reproduces an image based on an electric signal output from the solid-state imaging device. 4. The monitoring device according to claim 3, further comprising a mounting member for mounting on an eye of an observer. 5. A welding torch inserted into a portion to be welded for performing welding, a moving mechanism for moving the welding torch to the welding portion, an image of the welding portion and logarithmic conversion of incident light. And a welding device for monitoring the welding portion with the imaging device and moving the welding torch with a moving mechanism to perform welding. 6. The welding apparatus according to claim 5, further comprising a detection circuit for detecting a position of a welding line or a molten pool from an output of the imaging device. 7. The welding apparatus according to claim 6, wherein a welding condition is changed according to a detection result of the detection circuit. 8. A welding operation method, wherein a welding portion is monitored by using the monitoring device according to any one of claims 2 to 4. 9. A welding operation method, wherein the welding operation is performed by the welding apparatus according to claim 5. Description: