JP2001218100A - Infrared image pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the accurate temperature distribution of an object to be picked up by eliminating a fixed pattern showing an inhomogeneous temperature distribution on a screen after calibration is performed in an infrared image pickup device. SOLUTION: A correction surface where its surface temperature is uniform is added in order to accurately detect a temperature distribution due to heat generated inside the infrared image pickup device and heat received from an outer environment in the case of performing calibration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infrared imaging apparatus mounted on a moving body such as an aircraft or a vehicle, which has a structure for reducing the influence of a temperature distribution during calibration, and provides a stable and stable image. The present invention relates to an infrared imaging device to be obtained.

[0002]

2. Description of the Related Art In an infrared imaging apparatus, an imaging element detects infrared light of an object to be imaged which enters through a lens and displays the image as an image.
Infrared rays generated inside the imaging device are also detected. In this case, the influence of infrared rays generated inside the imaging device is removed,
By performing calibration for correction, a correct infrared image of the object can be obtained. However, an infrared imaging device mounted on a base such as an aircraft or a vehicle is exposed to drastic changes in the external temperature environment during operation. Even if is performed, the internal temperature changes over time, affecting the captured image, causing shading or a fixed pattern to appear in the image. If a cooling mechanism or structure for keeping the temperature inside the imaging device constant to add this effect is added, the whole device becomes large and complicated, and is not suitable for mounting. For this reason, the infrared imaging device is provided with a black paint surface with low reflectivity and high radiation. For this purpose, a method of performing calibration and eliminating image unevenness is used.

FIG. 4 shows a conventional infrared imaging apparatus, in which a lens 1 and an infrared imaging element 2 are mounted on a frame 3. An infrared ray incident through the lens 1 is formed on the infrared imaging element 2, and the obtained image is output to a signal processor 4 from a cable (not shown) as an imaging signal. The frame 3 is supported on the base frame 7 by the first bearing 5 and the second bearing 6, and the direct motor 9 is driven by a command from the control device 8 to rotate relative to the base frame 7. Driven. A command error with respect to a command value of the control device 8 is detected by a gyro 10 attached to the frame 3 for detecting an angular velocity and an angle sensor 11, and fed back to the control device 8. The base frame 7 has a black paint film 12 having a low heat reflectance.

FIG. 5 is a diagram showing infrared rays incident on an infrared imaging device. Incident infrared rays 13 from the object to be imaged pass through the lens 1 and are collected and detected by the infrared imaging element 2. An infrared ray 14 radiated from the lens 1 is
And infrared rays 15 emitted from the frame 3 are also detected,
Because it is not possible to obtain an accurate infrared image of the object,
Calibration is performed to correct the effects of the infrared rays 14 emitted from the lens 1 and the infrared rays 15 emitted from the frame 3. FIG. 6 is a diagram illustrating execution of calibration of the imaging apparatus. The frame 3 is driven to rotate with respect to the base frame 7 and locked in a state where the frame 3 faces the black coating film 12. Since the black paint film 12 has a low reflectance and a low emissivity, an image is taken with the infrared optical system directly facing the black paint film 12 so that the entire image signal shows a uniform temperature. 2 is subjected to sensitivity correction, and calibration is performed. By calibrating the infrared imaging element 2, the influence of radiation, radiation, and reflection of heat generated by the imaging apparatus itself is removed, and an image of an accurate temperature distribution of the object to be imaged can be obtained.

[0005]

However, in such an infrared imaging device, when the sensitivity of the infrared imaging device is increased, the temperature of the use environment changes and the heat generated by the internal components generates the black image on the painted surface. The temperature distribution is not negligible for the detected temperature range. FIG. 7 is a diagram illustrating the imaging apparatus at the time of calibration. Irregular infrared rays 17 emitted from the image signal processor 4 installed in the base frame 7, infrared rays 17 emitted from the control device 8, and infrared rays 18 flowing from the outside, resulting in uneven temperature distribution of the black coating film 12. The infrared ray 19 emitted from the temperature correction surface, the infrared ray 14 emitted from the lens, and the infrared ray 15 emitted from the frame, together with the infrared ray 19, are incident on the infrared imaging element 2, and the entire image of the black coating film 12 after calibration is obtained. The sensitivity of the element is corrected so that the temperature shows a uniform temperature. Therefore, a pattern opposite to the temperature distribution of the black coating film 12, which is the temperature correction surface, remains on the screen, and the image of the accurate temperature distribution of the object to be imaged. There was a problem that could not be obtained.

The present invention has been made to solve the above problems in an infrared imaging apparatus.
It is an object of the present invention to obtain an infrared imaging device having a temperature correction surface for reducing the influence of sensitivity correction of an imaging device.

[0007]

According to the first aspect of the present invention, there is provided an infrared imaging apparatus comprising: a metal plate having one surface painted in black; a heat insulating material having one surface joined to the other surface of the metal plate; An infrared camera for photoelectrically converting incident infrared light to obtain an image signal, and means for performing calibration at a position where the infrared intake of the infrared camera faces the black painted surface of the metal plate.

According to a second aspect of the present invention, there is provided an infrared imaging apparatus comprising: a thermally conductive metal plate having one surface painted in black; a heat insulating material having one surface joined to the other surface of the metal plate; A base frame to which the other surface of the heat insulating material is joined, movably supported with respect to the base frame,
An infrared camera that photoelectrically converts infrared rays incident through a lens to obtain an image signal, and a driving unit that drives the infrared camera to a position where the lens faces a black painted surface of the metal plate.

The infrared imaging apparatus according to a third aspect of the present invention is a metal plate having one surface coated with black and having a plurality of flow paths through which a coolant flows, and a pipe for transferring the liquid to the flow path of the plate. A heat insulating material having one surface joined to the other surface of the metal plate, a base frame joined to the other surface of the heat insulating material, and a lens supported movably with respect to the base frame via a lens. An infrared camera that photoelectrically converts incident infrared rays to obtain an image signal, and a drive unit that drives the infrared camera to a position where the lens faces the black painted surface of the metal plate.

According to a fourth aspect of the present invention, there is provided an infrared imaging apparatus, wherein a metal plate having one surface painted black, a flat heater having one surface joined to the other surface of the plate, Thermal insulation joined to the other side of the heater;
A base frame to which the other surface of the heat insulating material is joined,
An infrared camera that is movably supported with respect to the base frame and obtains an image signal by photoelectrically converting infrared light incident through a lens, and the infrared camera at a position where the lens faces a black painted surface of the metal plate. And a driving unit for driving.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a temperature correction surface of the infrared imaging device according to the first embodiment of the present invention. The temperature correction surface is composed of a black paint film 12, a metal plate 20, and a heat insulating material 22 made of a foaming material.
The plate 20, the heat insulating material 22, and the base frame 7 are bonded and fixed by an adhesive layer 21 and an adhesive layer 23, respectively.
Reference numerals 1 to 11 are the same as those in the related art.

This embodiment is configured as described above.
As in the conventional case, the calibration of the imaging device is performed as shown in FIG. That is, the frame 3 is driven to rotate with respect to the base frame 7 and locked in a state where the frame 3 faces the black paint film 12. Since the black paint film 12 has a low reflectance and a low emissivity, an image is taken with the infrared optical system directly facing the black paint film 12 so that the entire image signal shows a uniform temperature. 2 is subjected to sensitivity correction, and calibration is performed.

At this time, the temperature distribution generated in the base frame 7 is generated by heat generated by internal devices such as the control device 8 and the signal processor 4 and heat applied from an external environment.
When the amount of heat generated inside the base frame 7 is small,
Since the thermal resistance of the heat insulating material 22 is large, the amount of heat transmitted to the plate 20 is small, and no temperature distribution occurs on the metal plate. When the amount of heat generated by the internal devices of the base frame 7 is large, the amount of heat reaches the plate 20, but since the heat resistance inside the plate 20 is small, the heat is diffused and the distribution is uniform.

On the other hand, even when heat is directly applied to the plate 20 from the outside, since the heat resistance of the heat insulating material 22 is large, the heat is diffused by the plate 20 and transmitted to the heat insulating material, and the temperature distribution of the plate 20 is increased. Becomes uniform.

By using the structure of the temperature correction surface in this embodiment for an infrared imaging device similar to the conventional one, the temperature distribution on the temperature correction surface is reduced, and an uneven fixed pattern ( (A pattern opposite to the temperature distribution on the temperature correction surface), and an image showing the accurate temperature distribution of the object to be imaged can be obtained.

Embodiment 2 FIG. 2 is a configuration diagram of a temperature correction surface of the infrared imaging device according to the second embodiment of the present invention. The temperature correction surface includes a black coating film 12, a metal plate 24 having a plurality of flow paths for a coolant, a heat insulating layer 26 made of a foaming material, a pipe 28 and a pipe 29 joined to the plate 24, Plate 24, heat insulation layer 2
6. The base frame 7 is adhesively fixed by an adhesive layer 25 and an adhesive layer 27, respectively.

The coolant is circulated from the pipe 28 to the pipe 29 via the plate 24. By circulating the coolant through the plurality of flow paths, the temperature of the plate 24 is kept constant. In addition, heat conduction from the base frame 7 is blocked by the heat insulating layer 26, and heat applied to the plate 24 from the outside is diffused in the plate 24, so that the temperature of the plate becomes constant as a whole.

By using the structure of the temperature correction surface in the present embodiment for an infrared imaging device similar to the conventional one, the temperature distribution on the temperature correction surface is reduced, and the fixed pattern on the screen generated during calibration is eliminated.

Embodiment 3 FIG. 3 is a configuration diagram of a temperature correction surface of the infrared imaging device according to the third embodiment of the present invention. The temperature correction surface is composed of a black paint film 12, a metal plate 30, a heater 31 having a planar shape, and a heat insulating layer 32 made of a foaming material. The adhesive layers 33, 34, and 35 bond each other. Fixed.

The heater 31 includes a cable 36 and a cable 3
7, is connected to a power supply 38, is supplied with electric power, and generates heat. The heat generated by the heater 31
2 and does not transfer heat to the base frame 7. Also,
The heat from the base frame 7 is not transferred to the heater 31. The heat transmitted from the heater 31 to the plate 30 is diffused because the thermal resistance in the plate 30 is low, and the entire plate 30 is maintained at a constant temperature by the heater 31. By using the structure of the temperature correction surface in this embodiment for an infrared imaging device similar to the conventional one, the temperature distribution of the temperature correction surface is reduced, and the fixed pattern on the screen generated at the time of calibration is eliminated.

[0021]

Since the present invention is configured as described above, it has the following effects.

According to the first and second aspects of the present invention, the temperature correction surface is formed by using the metal plate having the black painted surface and the heat insulating material bonded to the metal plate, so that the on-screen generated at the time of calibration is generated. This has the effect of eliminating the fixed pattern.

According to the third aspect of the present invention, the temperature correction surface is formed by using a metal plate having a black painted surface and having a plurality of flow paths for flowing the cooling liquid and a heat insulating material joined to the metal plate. There is an effect that a fixed pattern on the screen generated at the time of calibration can be eliminated.

According to the fourth aspect, the temperature correction surface is formed by using a metal plate having a black painted surface, a flat heater joined to the metal plate, and a heat insulating material joined to the heater. There is an effect that a fixed pattern on the screen generated at the time of calibration can be eliminated.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a temperature correction surface according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of a temperature correction surface according to Embodiment 2 of the present invention.

FIG. 3 is a configuration diagram of a temperature correction surface according to a third embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional infrared imaging device.

FIG. 5 is a diagram of infrared light incident on an image sensor of an infrared imaging apparatus.

FIG. 6 is a diagram of the infrared imaging apparatus when performing calibration.

FIG. 7 is a diagram of the infrared imaging apparatus when performing calibration.

[Explanation of symbols]

1 lens, 2 infrared imaging devices, 3 frames, 4
Image signal processor, 5 first bearing, 6 second bearing, 7
Base frame, 8 control device, 9 direct motor, 10 gyro, 11 angle detector, 12 black paint film, 13 incident infrared light, 14 infrared light emitted from lens, 15 infrared light emitted from frame, 16 infrared light emitted from control device, 17 images Infrared rays emitted from the signal processor, 18 infrared rays coming in from the outside, 19 infrared rays emitted from the temperature correction surface, 20 plates, 21 adhesive layers, 22 heat insulating material, 23 adhesive layers, 24 plates, 2
5 adhesive layers, 26 heat insulating layers, 27 adhesive layers, 28 pipes, 29 pipes, 30 plates, 31 heaters, 3
2 Insulation material, 33 adhesive layers, 34 adhesive layers, 35 adhesive layers, 36 cables, 37 cables, 38 power supply.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) H04N 17/00 H04N 17/00 K

Claims (4)

[Claims] 1. A metal plate having one surface painted black, a heat insulating material having one surface joined to the other surface of the metal plate, and an infrared camera for photoelectrically converting incident infrared light to obtain an image signal. Means for performing calibration at a position where the infrared intake port of the infrared camera faces the black painted surface of the metal plate. 2. A heat conductive metal plate having one surface painted in black, a heat insulating material having one surface joined to the other surface of the metal plate, and a heat insulating material joined to the other surface of the heat insulating material. A base frame, an infrared camera that is movably supported with respect to the base frame, and that obtains an image signal by photoelectrically converting infrared rays incident through a lens, and that the lens has a black painted surface of the metal plate during calibration. And a driving unit for driving the infrared camera to a position facing the infrared camera. 3. A metal plate having one surface coated with black and having a plurality of flow paths through which a cooling liquid flows, a pipe for transferring the cooling liquid to the flow path of the plate, and one surface formed of the metal A heat insulating material bonded to the other surface of the plate, a base frame to which the other surface of the heat insulating material is bonded, and a photoelectrically converted infrared ray which is movably supported with respect to the base frame and which enters through a lens. An infrared camera for obtaining an image signal; and a drive unit for driving the infrared camera to a position where the lens faces the black painted surface of the metal plate during calibration. 4. A metal plate having one surface coated with black, a flat heater having one surface bonded to the other surface of the metal plate, and one surface bonded to the other surface of the heater. Heat insulation material, a base frame to which the other surface of the heat insulation material is joined, and an infrared camera that is movably supported with respect to the base frame and that photoelectrically converts infrared light incident through a lens to obtain an image signal. And an actuator for driving the infrared camera to a position where the lens faces the black painted surface of the metal plate during calibration.