JPH0555055U - Infrared thermal imager - Google Patents

Abstract

(57) [Summary] [Purpose] When the number of passing of the monitored object is small,
The infrared thermal imager is deactivated to prolong the service life of the rotary mirror and reduce power consumption. [Structure] First and second position sensors installed by detecting and outputting the position of an object and positioned outside the monitoring area, and a drive circuit of a raster scanning unit by the outputs of both position sensors. The raster scanning unit includes a control circuit that outputs a control signal for turning on / off and a first switch circuit that turns on / off the drive circuit according to the control signal. The first position sensor detects an object and a raster scanning unit. Turn on the drive circuit of the second
Infrared thermal imager that detects the passage of an object with the position sensor and turns off the drive circuit. [Effect] The service life of the rotary mirror is extended. Power consumption can be saved and factory maintenance costs can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an infrared thermal imager used in an industrial monitoring system for monitoring an object on a production line such as a steel mill or an automobile factory.

[0002]

[Prior Art]

 In general, in steel mills, etc., in order to carry molten iron, etc., a top car (hereinafter referred to as TPC) made of refractory bricks and having a length of 16 m and a height of 6.2 m is used. Has been. This TPC has a high-temperature metal member such as molten iron put inside, and is set at a constant speed for 20 to 30 minutes on a rail laid at a predetermined place in an unmanned factory. It is configured to move to a point. However, since TPC transports high-temperature metal parts, the refractory bricks gradually decrease with the passage of time, and holes may open in the wall or bottom surface, resulting in an accident. Therefore, there is a monitoring system that prevents accidents by monitoring the surface temperature of TPC and detecting the opening of holes.

This is a method for measuring the surface temperature of a TPC using a mechanical raster scanning infrared thermal imager and a factory computer (hereinafter, referred to as FC) to measure the deterioration of the inner wall of the TPC. When the TPC reaches a predetermined position in the detection system, the surface temperatures of both sides of the TPC measured by the infrared thermal imaging device are taken into the FC, and the "precaution temperature, abnormal temperature" is set. The comparison is made and the result is output to the FC display screen. The infrared thermal imager used to measure the surface temperature of the TPC in this system includes a mechanical raster scan type.

In this device, when light from an object such as TPC is transmitted through a silicon window, visible light is blocked and only infrared rays pass through and enter the infrared camera. This infrared light is incident on a rotating mirror arranged in a plane mirror of 10 faces, reflected by each mirror, and scanned in horizontal and vertical directions. This scanning light is reflected by a folding mirror. Then, it enters the infrared detector through a condenser lens, is photoelectrically converted, and is output as a thermal image signal. The electric signal output from the infrared detector is amplified by an amplifier, and various kinds of signal processing are performed in the processor. The result is supplied to a display device such as a cathode ray tube so that a thermal image of the object is displayed. ..

Normally, the number of horizontal scanning lines of this type of infrared thermal imaging device is about 100, and in order to display a thermal image in real time by using a mechanical scanning mechanism, the rotary mirror is 14,400 rpm. It rotates at high speed in the front and back, and displays 15 pixels per second.

[0006]

[Problems to be solved by the device]

 In order to display a thermal image in real time, the rotating mirror must be rotated at a high speed of 14,400 rpm, so the rotating shaft of the rotating mirror is physically worn. For example, when rotating at such a high speed, the life of the rotary shaft of the rotary mirror is about 8000 hours, so that there is a problem that the useful life of the rotary mirror is only about one year. On the other hand, if the object continues to flow in the production line monitored by the infrared thermal imager, it can be said that it is in use for 24 hours, but the object such as TPC in the steel mill is In the case of monitoring, it only passes every 20 to 30 minutes, and the rotary mirror is spinning unnecessarily while the TPC does not pass. Moreover, depending on the factory in which this system is installed, the object to be monitored may only pass through it several times a day. In such a case, the monitoring system is activated all day long. There is also a problem that it is uneconomical to waste electricity because it wastes power.

[0007]

[Means for solving problems]

 This device detects the position of an object and outputs a signal indicating that the object exists, and the first and the first devices are located outside the monitoring area in the moving direction of the object and are separated by a predetermined distance. The second position sensor is connected to the second position sensor, and the first position sensor is connected to the second position sensor by a control signal for turning on the drive circuit by the signal of the presence of the object of the first position sensor. A control circuit connected to the second position sensor, which outputs a control signal for turning off the drive circuit in response to a signal indicating that the object is present, and a control circuit which is connected to the control circuit and turns on the drive circuit according to the control signal. With the first switch circuit that is turned off, the first position sensor detects the target object and turns on the drive circuit of the raster scanning unit, and the second position sensor detects the passage of the target object. The drive circuit was turned off Than it is.

Further, the control circuit is provided with a relay circuit which is turned off by the signal of the object of the first position sensor, and is set when the off operation of the relay circuit is detected and turned off after a predetermined time. The second switch circuit, which has a timer circuit that operates and a power relay circuit that turns off when the timer circuit is turned off, is connected to the main power circuit of the infrared thermal imaging device, and the drive circuit is turned on. The main power circuit is turned off after a predetermined time from the time.

[0009]

[Action]

 The first and second position sensors-9 and 10 are always set to the operating state. When the object 1 does not exist between the installation positions D and E of the position sensors 9 and 10, the drive circuit 15 of the infrared camera head unit 5 and the main power supply circuit 16 are turned off. Therefore, the infrared thermal imaging device 3 is inactive. Therefore, when the target object 1 reaches the first position sensor-9 installed in front of the monitoring area B, a signal indicating that the target object is present is output, and the timer circuit 24 is set by this signal, and the power relay is set. -The circuit 25 is turned on, the power supply circuit 16 is also turned on, the infrared thermal imaging device 3 is activated, and the timer-circuit 25 starts counting time. At the same time, the high-level control signal of the control circuit 17 is input to the switch circuit 21 to turn it on, the drive circuit 15 of the rotary mirror 51 of the infrared camera head 5 is driven, and the rotary mirror 51 rotates. To do. Next, when the object 1 reaches the monitoring area B, the surface temperatures of both side surfaces are measured here, and the measurement results are taken into the FC 4 and monitored. Further, when the object 1 reaches the position sensor-10, a control signal for turning off the drive circuit 15 is output from the control circuit 17 by the signal indicating that the object exists, the switch circuit 21 is turned off, and the drive circuit 15 is turned off. Then, the rotation of the rotation mirror 51 is stopped. On the other hand, since the timer circuit 24 is turned off after a preset time set by the position sensor 9 signal indicating that there is an object, the power relay circuit 25 is also turned off and the infrared thermal imager 3 The power supply circuit 16 which is the main power supply is turned off, and the infrared thermal imaging device 3 is deactivated.

[0010]

[Example of device]

 A case where the embodiment of the present invention is applied to a monitoring system for a top car (TPC) in a steel mill will be described in detail with reference to FIGS. 1 is a block diagram of the monitoring system, FIG. 2 is a circuit diagram of the main part, FIG. 3 is a waveform diagram of the control circuit 17, and FIG. 4 is a main part of the mechanical raster scanning part of the newly developed infrared thermal imager 3. It is a perspective view. First, an infrared thermal imager having a newly developed mechanical raster scanning unit will be described with reference to FIG. As shown in FIG. 4, a rotating mirror 51 in which a plane mirror 50 having eight faces is arranged in an annular shape, a silicon window 52 that blocks visible light and allows only infrared rays L to pass, and an object such as a TPC that passes through the silicon window 52. The first reflection mirror 53 for totally reflecting the infrared image of the image, the vibration mirror 54 and the rotation mirror 51 for vertically scanning the reflection light from the reflection mirror 53 and reflecting the reflected light on the plane mirror 50 of the rotation mirror 51. A second reflection mirror 55 for totally reflecting the infrared image scanned in the horizontal direction by the plane mirror 50, a condenser lens 57 for forming the reflected light of the reflection mirror 55 on the infrared detector 56, An amplifier 58 for amplifying the electric signal output from the red line detector 56 is provided. The output signal from the amplifier 58 is subjected to various kinds of signal processing in the processor 59, and the result is supplied to a display device 60 such as a cathode ray tube so that a thermal image of the object is displayed.

With this configuration, only the infrared ray L from the object passes through the silicon window 52 and is totally reflected by the reflection mirror 53 to reach the vibration mirror 54. Since this infrared image is shaken by 10 degrees in the vertical direction by the vibration mirror 54, each plane mirror 50 of the rotating mirror 51 scans the surface of the slightly deviated portion of the vibration mirror 54 in the horizontal direction. .. Normally, the number of horizontal scanning lines of this type of infrared thermal imager is about 100. Therefore, when the octahedral rotating mirror 51 is used, it is at least 13 while the vibration mirror 54 shakes 10 degrees. It is necessary to rotate, and the rotation mirror 51 is configured to scan a range of 10 degrees in the vertical direction by 13 rotations.

On the other hand, since the infrared detector 56 receives the thermal image signal at every 0.1 degree by the flat mirror 50 on one surface, one rotation of the rotating mirror 51 scans the object in the vertical direction of 10 degrees. In the horizontal direction, the horizontal viewing angle (15 degrees) of each plane mirror 50 of the rotating mirror 51 is scanned. Therefore, in order to display a thermal image in real time by using such a mechanical scanning mechanism, rotating the rotary mirror 51 at a high speed of about 14,400 rpm gives a display of 15 pixels per second. Be done. Next, referring to FIGS. 1 and 2, as described in the conventional example, a TPC (made of refractory bricks) for transporting high-temperature metal members such as molten iron is used in a steel mill or the like. Object 1) is used, and this is configured to move at a constant speed to a target point as shown by an arrow A on a rail 2 laid at a predetermined location in an unmanned factory. ing. Therefore, a monitoring system is installed in the factory to monitor the surface temperature of this TPC1 to detect the deterioration of the inner wall and prevent accidents due to the opening of holes.

In this surveillance system, an infrared camera head section 5 of a mechanical raster scanning infrared thermal imaging device 3 is installed at a substantially central portion of the surveillance area B, and is provided at a position away from the surveillance area B. An infrared image processing unit 6 and a factory computer (hereinafter, referred to as FC) 4 are installed in the existing monitor area.

Further, a pair of position sensors-7 and 8 are installed at both ends of the monitoring area B (both ends in the moving direction of the object 1), and further outside the position sensors-7 and 8, That is, the light emitting portions 9a and 10a and the light receiving portions 9b and 10b of the pair of first and second position sensors 9 and 10 are located outside the monitoring area, and the light emitting portions 9a and 10a and the light receiving portions 9b and 10b are predetermined along the moving direction of the object 1. They are installed at installation positions D and E, respectively, separated by a distance C. The position sensors 9 and 10 are of the same type and have built-in relays 9c and 10c which are normally closed. When the object 1 shields the infrared rays L, the relays 9c and 10c are opened. In addition to the above structure, an independent power supply circuit 11 is connected to keep the position sensors 9 and 10 in an operating state at all times.

The distance C between the installation positions D and E of the position sensor 9 and the position sensor 10, that is, the predetermined distance C is usually determined by the moving speed of the object 1, and the infrared detector 56 (FIG. 4). ) Is sufficiently cooled by the cooling unit, and is extended to the outside of the monitoring area B by the distance that the object 1 moves during the time (usually about 20 to 30 seconds is required) during which it operates stably. It is the point where it was done. Reference numeral 12 is an interface incorporating a character recognition device 13, and 14 is an FC4 monitor.

The infrared camera head unit 5 has a built-in drive circuit 15 for turning on / off the rotation of the rotation mirror 51 of the mechanical raster scanning unit shown in FIG. Circuit 16 turns the entire device on and off. Reference numeral 17 is a control circuit for ON / OFF controlling the drive circuit 15, and in this embodiment, it is composed of a normally closed relay circuit 18, a NOT circuit 19, and an RS flip-flop circuit 20. When the position sensor 9 is opened, the relay circuit 18 is also opened and turned off. R1 and R2 are the input resistances of the set terminal and the reset terminal of the RS flip-flop circuit 20, respectively. The set signal of the RS flip-flop circuit 20 (the signal with the object from the position sensor 9) (Fig. 3 (a)). ) Is input from the relay circuit 18 to the set terminal of the RS flip-flop circuit 20 via the input resistor R1, and the reset signal from the position sensor-10 (the object presence signal from the position sensor-10) (Fig. 3 ( b)) is input from the input resistor R2 through the NOT circuit 19 to the reset terminal of the RS flip-flop circuit 20. In the time interval t between the set signal and the reset signal shown in FIGS. 3A and 3B, the object 1 moves a predetermined distance C (distance between the installation position D and the installation position E). Equal to time

Reference numeral 21 is a first switch circuit for turning on / off the drive circuit 15. When a signal from the RS flip-flop circuit 20 is input to the base, a transistor Tr that performs a switch operation and a collector of this transistor Tr are provided. The relay circuit 22 is connected to the relay circuit 22. A second switch circuit 23 is a timer circuit 24 which is set when an off operation of the relay circuit 18 is detected and turns off after a predetermined time T, and a power relay which is turned off by the operation of the timer circuit 24. The circuit 25 is connected in series. In this embodiment, the timer circuit 24 is an off-power delay timer which is turned off after a predetermined time T. The output terminal of the power relay circuit 25 is connected to the main power supply circuit 16 of the infrared thermal imaging device 3.

Next, the action and operation will be described with reference to FIGS. 1, 2 and 4. The power supply circuit 11 is always turned on, and the first and second position sensors 9 and 10 are always set to the operating state. Therefore, the infrared beams from the light emitting portions 9a and 10a are received by the light receiving portions 9b and 10b, respectively, and the relays 9c and 10c are closed. Therefore, when the object 1 does not exist between the installation positions D and E of the position sensors 9 and 10, not only the drive circuit 15 of the infrared camera head unit 5 but also the main power supply circuit 16 It is off, and the infrared thermal imaging device 3 is inactive.

On the other hand, in the steel mill, a TPC (object) 1 is moving in the direction of arrow A on the laid rail 2 at a constant speed at intervals of 10 to 20 minutes. When the TPC1 reaches the installation position D of the first position sensor 9 installed in front of the monitoring area B, the infrared beam from the light emitting section 9a is shielded by the TPC1 and the relay 9c is released. Is opened and the signal with the object is output. In this way, when the relay 9c is opened, the current from the power supply circuit 11 does not flow into the coil of the relay circuit 18, so that the relay circuit 18 is opened and turned off. At the same time when the relay circuit 18 is turned off, the trigger signal is input to the timer circuit 24, the timer circuit 24 is set, the time counting is started, and the power relay circuit 25 is turned on to turn on the power supply. Since the circuit 16 is also turned on, the infrared thermal imager 3 is activated. At the same time, the set signal shown in FIG. 3 (a) is input to the set terminal of the RS flip-flop circuit 20 from the input resistor R1 to set the RS flip-flop circuit 20, and as shown in FIG. 3 (c), The Q signal end becomes high level. When this high-level signal is input to the base of the transistor Tr, the transistor Tr turns on and a current flows from the collector to the emitter, and the relay circuit 22 turns on, so that the infrared camera head 5 rotates. The drive circuit 15 of the mirror 51 is driven and the rotary mirror 51 rotates.

Next, when the TPC 1 reaches the monitoring area B, the position sensor-7 detects it and the infrared thermal imaging device 3 measures the surface temperature of both side surfaces of the TPC 1, and the measurement result is taken into the FC 4. Then, the result is compared with a preset “warning temperature, abnormal temperature” and the result is output to the display screen of the monitor 14. In this way, the measurement of the surface temperature of the TPC1 is continued until the TPC1 reaches the position sensor-8. Further, when the TPC1 reaches the position sensor-10, the infrared beam from the light emitting section 10a is shielded by the TPC1 in the same manner as described above, so that the relay-10c is opened and a signal indicating that the object exists is output. It When the relay 10c is opened, the reset signal shown in FIG. 3B is input from the input resistor R2 to the reset terminal of the RS flip-flop circuit 20 via the NOT circuit 19. By this reset signal, the RS flip-flop circuit 20 is reset and the Q signal terminal becomes low level. When the Q signal terminal goes low, the base current of the transistor Tr is cut off, so that no current flows from the collector to the emitter, the transistor Tr turns off, and the relay circuit 22 turns off. Therefore, the drive circuit 15 of the rotary mirror 51 is turned off, and the rotation of the rotary mirror 51 is stopped.

On the other hand, since the timer circuit 24 is turned off after a predetermined time T set by the signal of the object of the position sensor 9 is set, the power relay circuit 25 is also turned off, and accordingly, The power supply circuit 16 which is the main power source of the infrared thermal imaging device 3 is turned off, and the infrared thermal imaging device 3 is deactivated. The predetermined time T of the timer circuit 24 is set to be a time longer than the time t during which the object 1 moves from the installation position D to the installation position E in the normal operation state. When the objects 1 pass as a group in a relatively complicated manner, only the drive circuit 15 can be turned on / off for a predetermined time T. The predetermined distance C from the installation position D to E and the predetermined time T of the timer circuit 24 are set in consideration of the moving speed of the object 1, the range of the monitoring area, and the time until the infrared detector 56 is sufficiently cooled. Will be decided. In this embodiment, the power supply circuit 16 is a power supply independent of the drive circuit 15. However, the power supply circuit 16 is connected so as to supply power to the drive circuit 15, and when the power supply circuit 16 is turned off, the drive circuit 15 is turned off. Even if it is configured to be turned off, the same effect can be obtained. The present invention is not limited to the above-described embodiment, and the timer circuit 24 is simply turned on so that the power supply circuit 16 is turned on, for example, for 10 minutes after the position sensor 9 detects the object 1. Can also be set.

[0022]

The device of the present invention detects the position of an object and outputs a signal indicating that the object exists, and the device is located outside the monitoring area in the moving direction of the object and is installed at a predetermined distance. A first and a second position sensor which are present, and a control signal which is connected to the first position sensor and which turns on the drive circuit by a signal of the presence of the object of the first position sensor; And a control circuit for outputting a control signal for turning off the drive circuit according to a signal of the presence of the object of the second position sensor, and a control circuit connected to the control circuit for driving by the control signal. A first switch circuit that turns the circuit on and off, the first position sensor detects the target object, turns on the drive circuit of the raster scanning unit, and the second position sensor detects the target object. Detects passage and turns off the drive circuit Therefore, when the distance between the objects on the manufacturing line passing through the monitoring area is long, the rotation of the rotary mirror can be stopped, so that the rotary shaft of the rotary mirror is less worn and the rotation of the rotary mirror is reduced. The service life is significantly longer. In addition, if the object passes through the surveillance area only a few times a day, not only the rotation of the rotating mirror but also the main power supply of the infrared thermal imaging device is turned off, and the entire surveillance system is turned off. Since it can be maintained in the operating state, the service life of the entire device is extended, power consumption is saved, and the maintenance cost of the factory can be reduced. In addition, the operating time and the non-operating time of the entire system can be set arbitrarily by the time interval for the object to pass through the monitoring area, so it can be applied to any factory line.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an essential part showing an embodiment of the present invention.

FIG. 2 is a block diagram of a monitoring system showing an embodiment of the present invention.

FIG. 3 is a waveform diagram of a control circuit according to the embodiment of the present invention.

FIG. 4 shows an embodiment of the present invention, and is a perspective view of a main part of a mechanical raster scanning unit of a newly developed infrared thermal imager.

[Explanation of symbols]

 1 Object 3 Infrared Thermal Imaging Device 5 Infrared Camera Head 9 First Position Sensor-10 Second Position Sensor-11 Power Supply Circuit 15 Drive Circuit 16 Main Power Supply Circuit 17 Control Circuit 18 Relay Circuit 21 First Switch Circuit 22 Relay circuit 23 Second switch circuit 24 Timer circuit 25 Power relay circuit B Monitoring area C Predetermined distance D Position sensor-9 installation position E Position sensor-10 installation position T Timer circuit predetermined time

Claims (2)

[Scope of utility model registration request] 1. An infrared thermal imaging apparatus comprising: a mechanical raster scanning unit having horizontal and vertical scanning mechanisms for two-dimensionally scanning an object in a monitoring area; and a drive circuit for driving the mechanical raster scanning unit. , A first and a second that are respectively installed at a predetermined distance apart from the monitoring area in the moving direction of the object while detecting the position of the object and outputting a signal indicating that the object exists. Position sensor, and a control signal connected to the first position sensor for turning on the drive circuit in response to the signal of the presence of the object of the first position sensor, and the second position sensor. A control circuit which is connected to the second position sensor and outputs a control signal for turning off the drive circuit in response to the signal of the presence of the object of the second position sensor; A first switch circuit for turning on / off the drive circuit, and the first position sensor detects the object to turn on the drive circuit of the raster scanning unit;
An infrared thermal imaging apparatus, wherein the position sensor detects the passage of the object and turns off the drive circuit. 2. The control circuit is provided with a relay circuit which is turned off by a signal of the presence of an object of the first position sensor, and is set when an off operation of the relay circuit is detected and turned off after a predetermined time. A second switch circuit having an operating timer circuit and a power relay circuit which is turned off when the timer circuit is turned off is connected to a main power supply circuit of the infrared thermal imaging device to turn on the drive circuit. The infrared thermal imaging apparatus according to claim 1, wherein the main power supply circuit is turned off after the predetermined time from the time when the infrared thermal imaging device is turned on.